Mark AckPacer @unchecked Sendable

Its mutable state is confined to the serial pacer queue; the annotation
silences the capture-of-non-Sendable warning in the scheduler callback
(NostrTransport.swift:123) under the app target's concurrency checking.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Configs/Release.xcconfig

@@ -1,4 +1,4 @@
-MARKETING_VERSION = 1.5.4
+MARKETING_VERSION = 1.6.0
 CURRENT_PROJECT_VERSION = 1
 
 IPHONEOS_DEPLOYMENT_TARGET = 16.0

bitchat/App/AppChromeModel.swift

@@ -18,6 +18,9 @@ final class AppChromeModel: ObservableObject {
     private let chatViewModel: ChatViewModel
     private var cancellables = Set<AnyCancellable>()
 
+    /// Bulletin-board coordinator, created on first use of the board sheet.
+    private(set) lazy var boardManager = BoardManager(transport: chatViewModel.meshService)
+
     init(chatViewModel: ChatViewModel, privateInboxModel: PrivateInboxModel) {
         self.chatViewModel = chatViewModel
         self.nickname = chatViewModel.nickname
@@ -59,6 +62,28 @@ final class AppChromeModel: ObservableObject {
         isAppInfoPresented = true
     }
 
+    /// Builds the mesh topology map model from the transport's gossiped
+    /// graph plus the live nickname table. Unknown nodes (heard about via a
+    /// neighbor claim but never announced to us) fall back to a short ID.
+    func meshTopologyDisplayModel() -> MeshTopologyDisplayModel {
+        let mesh = chatViewModel.meshService
+        guard let snapshot = mesh.currentMeshTopology() else { return .empty }
+        let nicknames = mesh.getPeerNicknames()
+
+        let nodes = snapshot.nodes.map { peerID -> MeshTopologyDisplayModel.Node in
+            let isSelf = peerID == snapshot.localPeerID
+            let label: String
+            if isSelf {
+                label = chatViewModel.nickname
+            } else {
+                label = nicknames[peerID] ?? "\(peerID.id.prefix(8))…"
+            }
+            return MeshTopologyDisplayModel.Node(id: peerID.id, label: label, isSelf: isSelf)
+        }
+        let edges = snapshot.edges.map { ($0.a.id, $0.b.id) }
+        return MeshTopologyDisplayModel(nodes: nodes, edges: edges)
+    }
+
     func triggerScreenshotPrivacyWarning() {
         showScreenshotPrivacyWarning = true
     }

bitchat/App/AppRuntime.swift

@@ -28,6 +28,7 @@ final class AppRuntime: ObservableObject {
     let locationChannelsModel: LocationChannelsModel
     let peerListModel: PeerListModel
     let appChromeModel: AppChromeModel
+    let boardAlertsModel: BoardAlertsModel
 
     private let idBridge: NostrIdentityBridge
     private var cancellables = Set<AnyCancellable>()
@@ -91,6 +92,24 @@ final class AppRuntime: ObservableObject {
             chatViewModel: self.chatViewModel,
             privateInboxModel: self.privateInboxModel
         )
+        let chatViewModel = self.chatViewModel
+        self.boardAlertsModel = BoardAlertsModel(
+            arrivals: BoardStore.shared.postArrivals.eraseToAnyPublisher(),
+            wipes: BoardStore.shared.didWipe.eraseToAnyPublisher(),
+            dependencies: BoardAlertsModel.Dependencies(
+                isOwnPost: { post in
+                    let key = chatViewModel.meshService.noiseSigningPublicKeyData()
+                    return !key.isEmpty && key == post.authorSigningKey
+                },
+                emitSystemLine: { content, geohash in
+                    if geohash.isEmpty {
+                        chatViewModel.addMeshOnlySystemMessage(content)
+                    } else {
+                        chatViewModel.addGeohashSystemMessage(content, geohash: geohash)
+                    }
+                }
+            )
+        )
 
         GeoRelayDirectory.shared.prefetchIfNeeded()
         bindRuntimeObservers()

bitchat/App/ConversationUIModel.swift

@@ -193,7 +193,9 @@ final class ConversationUIModel: ObservableObject {
 
     private func refreshComputedState() {
         if let selectedPeerID = privateConversationModel.selectedPeerID {
-            canSendMediaInCurrentContext = !(selectedPeerID.isGeoDM || selectedPeerID.isGeoChat)
+            // Media transfer is not wired for groups in v1; keep it off so the
+            // composer can't strand a media placeholder that never sends.
+            canSendMediaInCurrentContext = !(selectedPeerID.isGeoDM || selectedPeerID.isGeoChat || selectedPeerID.isGroup)
             return
         }
 

bitchat/App/LocationChannelsModel.swift

@@ -12,20 +12,26 @@ final class LocationChannelsModel: ObservableObject {
     @Published private(set) var bookmarkNames: [String: String]
     @Published private(set) var locationNames: [GeohashChannelLevel: String]
     @Published private(set) var userTorEnabled: Bool
+    @Published private(set) var gatewayEnabled: Bool
 
     private let manager: LocationChannelManager
     private let network: NetworkActivationService
+    private let gateway: GatewayService
     private var cancellables = Set<AnyCancellable>()
 
     init(
         manager: LocationChannelManager? = nil,
-        network: NetworkActivationService? = nil
+        network: NetworkActivationService? = nil,
+        gateway: GatewayService? = nil
     ) {
         let manager = manager ?? .shared
         let network = network ?? .shared
+        let gateway = gateway ?? .shared
 
         self.manager = manager
         self.network = network
+        self.gateway = gateway
+        self.gatewayEnabled = gateway.isEnabled
         self.permissionState = manager.permissionState
         self.availableChannels = manager.availableChannels
         self.selectedChannel = manager.selectedChannel
@@ -96,6 +102,10 @@ final class LocationChannelsModel: ObservableObject {
         network.setUserTorEnabled(enabled)
     }
 
+    func setGatewayEnabled(_ enabled: Bool) {
+        gateway.setEnabled(enabled)
+    }
+
     func refreshMeshChannelsIfNeeded() {
         guard case .mesh = selectedChannel,
               permissionState == .authorized,
@@ -160,6 +170,10 @@ final class LocationChannelsModel: ObservableObject {
         network.$userTorEnabled
             .receive(on: DispatchQueue.main)
             .assign(to: &$userTorEnabled)
+
+        gateway.$isEnabled
+            .receive(on: DispatchQueue.main)
+            .assign(to: &$gatewayEnabled)
     }
 
     private func level(forLength length: Int) -> GeohashChannelLevel {

bitchat/App/PeerListModel.swift

@@ -14,6 +14,9 @@ struct MeshPeerRow: Identifiable, Equatable {
     let isMutualFavorite: Bool
     let encryptionStatus: EncryptionStatus
     let showsVerifiedBadgeWhenOffline: Bool
+    /// Vouched-for by someone I verified, without an explicit verification of
+    /// mine — rendered as the unfilled seal (verified gets the filled one).
+    let showsVouchedBadge: Bool
 
     var id: String { peerID.id }
 }
@@ -26,11 +29,22 @@ struct GeohashPersonRow: Identifiable, Equatable {
     let isBlocked: Bool
 }
 
+struct GroupChatRow: Identifiable, Equatable {
+    let peerID: PeerID
+    let name: String
+    let memberCount: Int
+    let isCreator: Bool
+    let hasUnread: Bool
+
+    var id: String { peerID.id }
+}
+
 @MainActor
 final class PeerListModel: ObservableObject {
     @Published private(set) var allPeers: [BitchatPeer] = []
     @Published private(set) var meshRows: [MeshPeerRow] = []
     @Published private(set) var geohashPeople: [GeohashPersonRow] = []
+    @Published private(set) var groupRows: [GroupChatRow] = []
     @Published private(set) var reachableMeshPeerCount = 0
     @Published private(set) var connectedMeshPeerCount = 0
     @Published private(set) var visibleGeohashPeerCount = 0
@@ -129,6 +143,13 @@ final class PeerListModel: ObservableObject {
             }
             .store(in: &cancellables)
 
+        chatViewModel.groupStore.$groups
+            .receive(on: DispatchQueue.main)
+            .sink { [weak self] _ in
+                self?.refresh()
+            }
+            .store(in: &cancellables)
+
         peerIdentityStore.$encryptionStatuses
             .receive(on: DispatchQueue.main)
             .sink { [weak self] _ in
@@ -183,13 +204,12 @@ final class PeerListModel: ObservableObject {
         let myPeerID = chatViewModel.meshService.myPeerID
         let meshRows = allPeers.map { peer in
             let isMe = peer.peerID == myPeerID
-            let verifiedBadge: Bool
-            if !isMe && !peer.isConnected,
-               let fingerprint = chatViewModel.getFingerprint(for: peer.peerID) {
-                verifiedBadge = peerIdentityStore.isVerified(fingerprint)
-            } else {
-                verifiedBadge = false
-            }
+            let fingerprint = isMe ? nil : chatViewModel.getFingerprint(for: peer.peerID)
+            let isVerifiedFingerprint = fingerprint.map { peerIdentityStore.isVerified($0) } ?? false
+            let verifiedBadge = !peer.isConnected && isVerifiedFingerprint
+            // Vouched is subordinate to verified: never show both seals.
+            let vouchedBadge = !isVerifiedFingerprint
+                && (fingerprint.map { chatViewModel.isVouchedFingerprint($0) } ?? false)
 
             return MeshPeerRow(
                 peerID: peer.peerID,
@@ -202,7 +222,8 @@ final class PeerListModel: ObservableObject {
                 isReachable: peer.isReachable,
                 isMutualFavorite: peer.isMutualFavorite,
                 encryptionStatus: chatViewModel.getEncryptionStatus(for: peer.peerID),
-                showsVerifiedBadgeWhenOffline: verifiedBadge
+                showsVerifiedBadgeWhenOffline: verifiedBadge,
+                showsVouchedBadge: vouchedBadge
             )
         }
 
@@ -217,22 +238,40 @@ final class PeerListModel: ObservableObject {
         }
 
         let geohashPeople = buildGeohashPeople()
+        let groupRows = buildGroupRows()
 
         self.meshRows = meshRows
         reachableMeshPeerCount = meshCounts.reachable
         connectedMeshPeerCount = meshCounts.connected
         self.geohashPeople = geohashPeople
         visibleGeohashPeerCount = geohashPeople.count
+        self.groupRows = groupRows
         renderID = (
             meshRows.map {
                 "\($0.id)-\($0.isConnected)-\($0.isReachable)-\($0.hasUnread)-\($0.isFavorite)-\($0.isBlocked)"
             } +
             geohashPeople.map {
                 "geo:\($0.id)-\($0.isTeleported)-\($0.isBlocked)-\($0.displayName)"
+            } +
+            groupRows.map {
+                "group:\($0.id)-\($0.name)-\($0.memberCount)-\($0.hasUnread)"
             }
         ).joined(separator: "|")
     }
 
+    private func buildGroupRows() -> [GroupChatRow] {
+        let myFingerprint = chatViewModel.meshService.noiseIdentityFingerprint()
+        return chatViewModel.groupStore.groups.map { group in
+            GroupChatRow(
+                peerID: group.peerID,
+                name: group.name,
+                memberCount: group.members.count,
+                isCreator: group.creatorFingerprint == myFingerprint,
+                hasUnread: chatViewModel.hasUnreadMessages(for: group.peerID)
+            )
+        }
+    }
+
     private func buildGeohashPeople() -> [GeohashPersonRow] {
         let myHex = currentGeohashIdentityHex()
         let teleportedSet = Set(locationPresenceStore.teleportedGeo.map { $0.lowercased() })

bitchat/App/PrivateConversationModels.swift

@@ -108,7 +108,13 @@ struct PrivateConversationHeaderState: Equatable {
     let encryptionStatus: EncryptionStatus?
 
     var supportsFavoriteToggle: Bool {
-        !conversationPeerID.isGeoDM
+        !conversationPeerID.isGeoDM && !conversationPeerID.isGroup
+    }
+
+    /// Group chats have no single peer identity behind the header: no
+    /// fingerprint screen, no per-peer encryption badge.
+    var isGroupConversation: Bool {
+        conversationPeerID.isGroup
     }
 }
 
@@ -206,6 +212,13 @@ final class PrivateConversationModel: ObservableObject {
             }
             .store(in: &cancellables)
 
+        chatViewModel.groupStore.$groups
+            .receive(on: DispatchQueue.main)
+            .sink { [weak self] _ in
+                self?.refreshSelectedConversation()
+            }
+            .store(in: &cancellables)
+
         NotificationCenter.default.publisher(for: Notification.Name("peerStatusUpdated"))
             .receive(on: DispatchQueue.main)
             .sink { [weak self] _ in
@@ -229,6 +242,26 @@ final class PrivateConversationModel: ObservableObject {
     }
 
     private func makeHeaderState(for conversationPeerID: PeerID) -> PrivateConversationHeaderState {
+        // Group chats: the "peer" is the whole crew. Name + member count in
+        // the header; availability reads as mesh since group traffic floods
+        // the local mesh, and the per-peer encryption badge does not apply.
+        if conversationPeerID.isGroup {
+            let displayName: String
+            if let group = chatViewModel.groupStore.group(for: conversationPeerID) {
+                displayName = "#\(group.name) (\(group.members.count))"
+            } else {
+                displayName = String(localized: "common.unknown", comment: "Fallback label for unknown peer")
+            }
+            return PrivateConversationHeaderState(
+                conversationPeerID: conversationPeerID,
+                headerPeerID: conversationPeerID,
+                displayName: displayName,
+                availability: .meshReachable,
+                isFavorite: false,
+                encryptionStatus: nil
+            )
+        }
+
         let headerPeerID = chatViewModel.getShortIDForNoiseKey(conversationPeerID)
         let peer = chatViewModel.getPeer(byID: headerPeerID)
         let displayName = resolveDisplayName(for: conversationPeerID, headerPeerID: headerPeerID, peer: peer)

bitchat/App/VerificationModel.swift

@@ -9,6 +9,14 @@ struct FingerprintPresentationState: Equatable {
     let theirFingerprint: String?
     let myFingerprint: String
     let isVerified: Bool
+    /// Number of currently-valid vouches from peers the user verified
+    /// (0 when the peer is explicitly verified — the stronger badge wins).
+    let voucherCount: Int
+    /// Display names of the (verified) vouchers, where known.
+    let voucherNames: [String]
+
+    /// Vouched for by ≥1 peer the user verified (and not explicitly verified).
+    var isVouched: Bool { voucherCount > 0 }
 
     var canToggleVerification: Bool {
         encryptionStatus == .noiseSecured || encryptionStatus == .noiseVerified
@@ -82,6 +90,24 @@ final class VerificationModel: ObservableObject {
         let encryptionStatus = chatViewModel.getEncryptionStatus(for: statusPeerID)
         let theirFingerprint = chatViewModel.getFingerprint(for: statusPeerID)
         let peerNickname = resolveDisplayName(for: peerID, statusPeerID: statusPeerID)
+        let isVerified = theirFingerprint.map { peerIdentityStore.isVerified($0) } ?? false
+
+        // Vouch state is recomputed on read: only vouchers still in the
+        // verified set count, so removing a verification silently retires the
+        // vouches that peer gave.
+        let vouchers: [VouchRecord]
+        if !isVerified, let theirFingerprint {
+            vouchers = chatViewModel.identityManager.validVouchers(for: theirFingerprint)
+        } else {
+            vouchers = []
+        }
+        let voucherNames = vouchers.compactMap { record -> String? in
+            guard let social = chatViewModel.identityManager.getSocialIdentity(for: record.voucherFingerprint) else {
+                return nil
+            }
+            if let petname = social.localPetname, !petname.isEmpty { return petname }
+            return social.claimedNickname.isEmpty ? nil : social.claimedNickname
+        }
 
         return FingerprintPresentationState(
             statusPeerID: statusPeerID,
@@ -89,7 +115,9 @@ final class VerificationModel: ObservableObject {
             encryptionStatus: encryptionStatus,
             theirFingerprint: theirFingerprint,
             myFingerprint: chatViewModel.getMyFingerprint(),
-            isVerified: theirFingerprint.map { peerIdentityStore.isVerified($0) } ?? false
+            isVerified: isVerified,
+            voucherCount: vouchers.count,
+            voucherNames: voucherNames
         )
     }
 
@@ -122,6 +150,17 @@ final class VerificationModel: ObservableObject {
                 self?.objectWillChange.send()
             }
             .store(in: &cancellables)
+
+        // Vouch state changes (ChatVouchCoordinator.notifyPeerTrustChanged)
+        // are signalled via this notification rather than a published
+        // property, so an open fingerprint sheet refreshes its vouched badge
+        // live when a vouch batch is accepted.
+        NotificationCenter.default.publisher(for: Notification.Name("peerStatusUpdated"))
+            .receive(on: DispatchQueue.main)
+            .sink { [weak self] _ in
+                self?.objectWillChange.send()
+            }
+            .store(in: &cancellables)
     }
 
     private func resolveDisplayName(for peerID: PeerID, statusPeerID: PeerID) -> String {

bitchat/BitchatApp.swift

@@ -40,6 +40,7 @@ struct BitchatApp: App {
                 .environmentObject(runtime.locationChannelsModel)
                 .environmentObject(runtime.peerListModel)
                 .environmentObject(runtime.appChromeModel)
+                .environmentObject(runtime.boardAlertsModel)
                 .onAppear {
                     appDelegate.runtime = runtime
                     runtime.start()

bitchat/Identity/IdentityModels.swift

@@ -126,13 +126,37 @@ struct SocialIdentity: Codable {
     var notes: String?
 }
 
+/// Trust ladder: unknown → casual → vouched → trusted → verified.
+///
+/// Persistence compatibility: `TrustLevel` is stored by its *String* raw
+/// value ("unknown", "casual", …), not by ordinal position, so inserting
+/// `vouched` mid-ladder cannot corrupt previously persisted values — every
+/// pre-existing case keeps the exact raw value it was written with. The
+/// `vouched` tier is additionally never persisted into `SocialIdentity`
+/// (it's recomputed on read from stored vouches), so downgraded builds never
+/// encounter the unfamiliar raw value.
 enum TrustLevel: String, Codable {
     case unknown
     case casual
+    /// Transitively trusted: vouched for by at least one peer *I* verified.
+    /// Derived at read time — never written to persistent storage.
+    case vouched
     case trusted
     case verified
 }
 
+// MARK: - Vouching (transitive verification)
+
+/// One accepted vouch: a peer I verified (the voucher) attested that they
+/// verified the vouchee. Validity is recomputed on read — a record only
+/// counts while its voucher remains in `verifiedFingerprints` and its
+/// timestamp is within `VouchAttestation.maxAge` — so unverifying a voucher
+/// silently invalidates the vouches they gave without a cascade delete.
+struct VouchRecord: Codable, Equatable {
+    let voucherFingerprint: String
+    let timestamp: Date
+}
+
 // MARK: - Identity Cache
 
 /// Persistent storage for identity mappings and relationships.
@@ -154,7 +178,22 @@ struct IdentityCache: Codable {
     
     // Blocked Nostr pubkeys (lowercased hex) for geohash chats
     var blockedNostrPubkeys: Set<String> = []
-    
+
+    // Vouching (transitive verification). All three fields are Optional so
+    // caches persisted before this feature decode cleanly — the synthesized
+    // decoder uses decodeIfPresent for optionals, and a missing key must not
+    // trip the "unreadable cache" recovery path that discards everything.
+
+    // Vouchee fingerprint -> accepted vouches (capped per vouchee)
+    var vouchesByVouchee: [String: [VouchRecord]]? = nil
+
+    // Peer fingerprint -> when we last sent them a vouch batch (rate limit)
+    var vouchBatchSentAt: [String: Date]? = nil
+
+    // Fingerprint -> when we verified it (orders outgoing vouch batches;
+    // entries verified before this field exists sort as oldest)
+    var verifiedAt: [String: Date]? = nil
+
     // Schema version for future migrations
     var version: Int = 1
 }

bitchat/Identity/SecureIdentityStateManager.swift

@@ -133,6 +133,17 @@ protocol SecureIdentityStateManagerProtocol {
     func setVerified(fingerprint: String, verified: Bool)
     func isVerified(fingerprint: String) -> Bool
     func getVerifiedFingerprints() -> Set<String>
+
+    // MARK: Vouching (transitive verification)
+    @discardableResult
+    func recordVouch(voucheeFingerprint: String, voucherFingerprint: String, timestamp: Date) -> Bool
+    func validVouchers(for fingerprint: String) -> [VouchRecord]
+    func isVouched(fingerprint: String) -> Bool
+    func effectiveTrustLevel(for fingerprint: String) -> TrustLevel
+    func lastVouchBatchSent(to fingerprint: String) -> Date?
+    func markVouchBatchSent(to fingerprint: String, at date: Date)
+    func signingPublicKey(forFingerprint fingerprint: String) -> Data?
+    func mostRecentlyVerifiedFingerprints(limit: Int, excluding fingerprint: String) -> [String]
 }
 
 /// Singleton manager for secure identity state persistence and retrieval.
@@ -550,16 +561,20 @@ final class SecureIdentityStateManager: SecureIdentityStateManagerProtocol {
         queue.async(flags: .barrier) {
             if verified {
                 self.cache.verifiedFingerprints.insert(fingerprint)
+                var verifiedAt = self.cache.verifiedAt ?? [:]
+                verifiedAt[fingerprint] = Date()
+                self.cache.verifiedAt = verifiedAt
             } else {
                 self.cache.verifiedFingerprints.remove(fingerprint)
+                self.cache.verifiedAt?.removeValue(forKey: fingerprint)
             }
-            
+
             // Update trust level if social identity exists
             if var identity = self.cache.socialIdentities[fingerprint] {
                 identity.trustLevel = verified ? .verified : .casual
                 self.cache.socialIdentities[fingerprint] = identity
             }
-            
+
             self.saveIdentityCache()
         }
     }
@@ -576,6 +591,159 @@ final class SecureIdentityStateManager: SecureIdentityStateManagerProtocol {
         }
     }
 
+    // MARK: - Vouching (transitive verification)
+
+    /// Maximum vouchers retained per vouchee (most recent kept).
+    static let maxVouchersPerVouchee = 8
+
+    /// Records an accepted vouch, enforcing every accept-policy gate that can
+    /// be evaluated against stored state (signature verification is the
+    /// caller's job — it needs the sender's announce-bound signing key):
+    /// - the voucher must be a fingerprint *I* verified
+    /// - self-vouches are ignored
+    /// - vouches for peers I already verified are ignored (nothing to add)
+    /// - attestations outside the validity window are ignored
+    /// - at most `maxVouchersPerVouchee` vouchers are kept per vouchee
+    ///
+    /// Returns true when the vouch was stored (or refreshed).
+    @discardableResult
+    func recordVouch(voucheeFingerprint: String, voucherFingerprint: String, timestamp: Date) -> Bool {
+        recordVouch(
+            voucheeFingerprint: voucheeFingerprint,
+            voucherFingerprint: voucherFingerprint,
+            timestamp: timestamp,
+            now: Date()
+        )
+    }
+
+    @discardableResult
+    func recordVouch(voucheeFingerprint: String, voucherFingerprint: String, timestamp: Date, now: Date) -> Bool {
+        queue.sync(flags: .barrier) {
+            guard voucheeFingerprint != voucherFingerprint,
+                  self.cache.verifiedFingerprints.contains(voucherFingerprint),
+                  !self.cache.verifiedFingerprints.contains(voucheeFingerprint) else {
+                return false
+            }
+            let age = now.timeIntervalSince(timestamp)
+            guard age <= VouchAttestation.maxAge, age >= -VouchAttestation.maxClockSkew else {
+                return false
+            }
+
+            var records = self.cache.vouchesByVouchee?[voucheeFingerprint] ?? []
+            if let index = records.firstIndex(where: { $0.voucherFingerprint == voucherFingerprint }) {
+                let newest = max(records[index].timestamp, timestamp)
+                records[index] = VouchRecord(voucherFingerprint: voucherFingerprint, timestamp: newest)
+            } else {
+                records.append(VouchRecord(voucherFingerprint: voucherFingerprint, timestamp: timestamp))
+            }
+            // Keep the most recent vouchers up to the cap.
+            records.sort { $0.timestamp > $1.timestamp }
+            let capped = Array(records.prefix(Self.maxVouchersPerVouchee))
+            guard capped.contains(where: { $0.voucherFingerprint == voucherFingerprint }) else {
+                return false // Full of fresher vouches; nothing changed.
+            }
+
+            var vouches = self.cache.vouchesByVouchee ?? [:]
+            vouches[voucheeFingerprint] = capped
+            self.cache.vouchesByVouchee = vouches
+            self.saveIdentityCache()
+            return true
+        }
+    }
+
+    /// The vouches that currently count for `fingerprint`. Validity is
+    /// recomputed here rather than maintained by cascade deletes: a record
+    /// only counts while its voucher is still verified-by-me and its
+    /// timestamp is within the expiry window.
+    func validVouchers(for fingerprint: String) -> [VouchRecord] {
+        validVouchers(for: fingerprint, now: Date())
+    }
+
+    func validVouchers(for fingerprint: String, now: Date) -> [VouchRecord] {
+        queue.sync {
+            self.validVouchersLocked(for: fingerprint, now: now)
+        }
+    }
+
+    /// Requires `queue`.
+    private func validVouchersLocked(for fingerprint: String, now: Date) -> [VouchRecord] {
+        guard let records = cache.vouchesByVouchee?[fingerprint] else { return [] }
+        return records.filter { record in
+            record.voucherFingerprint != fingerprint
+                && cache.verifiedFingerprints.contains(record.voucherFingerprint)
+                && now.timeIntervalSince(record.timestamp) <= VouchAttestation.maxAge
+        }
+    }
+
+    /// True when the peer has at least one valid vouch and no explicit
+    /// verification of ours.
+    func isVouched(fingerprint: String) -> Bool {
+        isVouched(fingerprint: fingerprint, now: Date())
+    }
+
+    func isVouched(fingerprint: String, now: Date) -> Bool {
+        queue.sync {
+            guard !self.cache.verifiedFingerprints.contains(fingerprint) else { return false }
+            return !self.validVouchersLocked(for: fingerprint, now: now).isEmpty
+        }
+    }
+
+    /// The trust level to display: explicit verification wins, then the
+    /// persisted level, with `vouched` layered in (derived, never persisted)
+    /// between `casual` and `trusted`.
+    func effectiveTrustLevel(for fingerprint: String) -> TrustLevel {
+        effectiveTrustLevel(for: fingerprint, now: Date())
+    }
+
+    func effectiveTrustLevel(for fingerprint: String, now: Date) -> TrustLevel {
+        queue.sync {
+            if self.cache.verifiedFingerprints.contains(fingerprint) { return .verified }
+            let stored = self.cache.socialIdentities[fingerprint]?.trustLevel ?? .unknown
+            let vouched = !self.validVouchersLocked(for: fingerprint, now: now).isEmpty
+            switch stored {
+            case .verified, .trusted:
+                return stored
+            case .vouched, .casual, .unknown:
+                if vouched { return .vouched }
+                // `.vouched` should never be persisted; degrade defensively.
+                return stored == .vouched ? .casual : stored
+            }
+        }
+    }
+
+    func lastVouchBatchSent(to fingerprint: String) -> Date? {
+        queue.sync { cache.vouchBatchSentAt?[fingerprint] }
+    }
+
+    func markVouchBatchSent(to fingerprint: String, at date: Date) {
+        queue.async(flags: .barrier) {
+            var sentAt = self.cache.vouchBatchSentAt ?? [:]
+            sentAt[fingerprint] = date
+            self.cache.vouchBatchSentAt = sentAt
+            self.saveIdentityCache()
+        }
+    }
+
+    /// The peer's announce-bound Ed25519 signing key, if seen this session.
+    func signingPublicKey(forFingerprint fingerprint: String) -> Data? {
+        queue.sync { cryptographicIdentities[fingerprint]?.signingPublicKey }
+    }
+
+    /// Verified fingerprints ordered most recently verified first (entries
+    /// without a recorded verification time sort last), excluding the given
+    /// fingerprint. Feeds the outgoing vouch batch.
+    func mostRecentlyVerifiedFingerprints(limit: Int, excluding fingerprint: String) -> [String] {
+        queue.sync {
+            let verifiedAt = cache.verifiedAt ?? [:]
+            let ordered = cache.verifiedFingerprints
+                .filter { $0 != fingerprint }
+                .sorted {
+                    (verifiedAt[$0] ?? .distantPast, $0) > (verifiedAt[$1] ?? .distantPast, $1)
+                }
+            return Array(ordered.prefix(limit))
+        }
+    }
+
     var debugNicknameIndex: [String: Set<String>] {
         queue.sync { cache.nicknameIndex }
     }

bitchat/Models/CommandInfo.swift

@@ -16,14 +16,18 @@ enum CommandInfo: String, Identifiable {
     // suggesting a spelling the processor rejects teaches users dead ends.
     case block
     case clear
+    case group
     case help
     case hug
     case message = "msg"
     case slap
+    case pay
     case unblock
     case who
     case favorite = "fav"
     case unfavorite = "unfav"
+    case ping
+    case trace
 
     var id: String { rawValue }
 
@@ -31,8 +35,12 @@ enum CommandInfo: String, Identifiable {
 
     var placeholder: String? {
         switch self {
-        case .block, .hug, .message, .slap, .unblock, .favorite, .unfavorite:
+        case .block, .hug, .message, .slap, .unblock, .favorite, .unfavorite, .ping, .trace:
             return "<" + String(localized: "content.input.nickname_placeholder") + ">"
+        case .group:
+            return "<" + String(localized: "content.input.group_placeholder") + ">"
+        case .pay:
+            return "<" + String(localized: "content.input.token_placeholder") + ">"
         case .clear, .help, .who:
             return nil
         }
@@ -42,24 +50,35 @@ enum CommandInfo: String, Identifiable {
         switch self {
         case .block:        String(localized: "content.commands.block")
         case .clear:        String(localized: "content.commands.clear")
+        case .group:        String(localized: "content.commands.group")
         case .help:         String(localized: "content.commands.help")
         case .hug:          String(localized: "content.commands.hug")
         case .message:      String(localized: "content.commands.message")
+        case .pay:          String(localized: "content.commands.pay")
         case .slap:         String(localized: "content.commands.slap")
         case .unblock:      String(localized: "content.commands.unblock")
         case .who:          String(localized: "content.commands.who")
         case .favorite:     String(localized: "content.commands.favorite")
         case .unfavorite:   String(localized: "content.commands.unfavorite")
+        case .ping:         String(localized: "content.commands.ping")
+        case .trace:        String(localized: "content.commands.trace")
         }
     }
 
     static func all(isGeoPublic: Bool, isGeoDM: Bool) -> [CommandInfo] {
-        let baseCommands: [CommandInfo] = [.block, .unblock, .clear, .help, .hug, .message, .slap, .who]
-        // The processor rejects favorites in geohash contexts, so only
-        // suggest them where they actually work: mesh.
-        if isGeoPublic || isGeoDM {
-            return baseCommands
+        var commands: [CommandInfo] = [.block, .unblock, .clear, .help, .hug, .message, .slap, .who]
+        // Cashu tokens are bearer instruments: in a public geohash any nearby
+        // stranger can redeem one, so don't *suggest* /pay there (the
+        // processor still allows it behind an explicit "public" confirm).
+        // Payments make sense in every DM and in mesh public.
+        if !isGeoPublic {
+            commands.append(.pay)
         }
-        return baseCommands + [.favorite, .unfavorite]
+        // The processor rejects favorites, groups, and mesh diagnostics in
+        // geohash contexts, so only suggest them where they work: mesh.
+        if isGeoPublic || isGeoDM {
+            return commands
+        }
+        return commands + [.favorite, .unfavorite, .ping, .trace, .group]
     }
 }

bitchat/Models/RequestSyncPacket.swift

@@ -1,19 +1,21 @@
+import BitFoundation
 import Foundation
 
 // REQUEST_SYNC payload TLV (type, length16, value)
 //  - 0x01: P (uint8) — Golomb-Rice parameter
 //  - 0x02: M (uint32, big-endian) — hash range (N * 2^P)
 //  - 0x03: data (opaque) — GR bitstream bytes (MSB-first)
-//  - 0x04: types (bitfield) — SyncTypeFlags of covered message types
-//  - 0x05: sinceTimestamp (uint64, big-endian) — oldest ts the filter covers
-//  - 0x06: fragmentIdFilter (utf8) — reserved
-//
-// TODO(v2): fragmentIdFilter (0x06) is parsed and re-serialized but never
-// populated or honored — it's the reserved surface for incremental fragment
-// sync (request the missing fragments of one file by ID instead of diffing the
-// whole fragment set). Either wire it into buildGcsPayload/_handleRequestSync
-// or drop the field; don't leave it as silent dead protocol surface.
+//  - 0x04: types (SyncTypeFlags) — packet types the filter covers
+//  - 0x05: sinceTimestamp (uint64, big-endian) — filter coverage cursor
+//  - 0x06: fragmentIdFilter (UTF-8) — comma-separated 16-hex-char (8-byte)
+//          fragment stream IDs; restricts the fragment diff to exactly those
+//          streams (targeted resync for stalled reassemblies)
 struct RequestSyncPacket {
+    /// Maximum fragment IDs one 0x06 filter may carry. Each ID encodes as
+    /// 16 hex chars plus a comma separator, so the largest encoded value is
+    /// 60 * 17 - 1 = 1019 bytes, which fits the 1024-byte decoder cap.
+    static let maxFragmentIdFilterCount = 60
+
     let p: Int
     let m: UInt32
     let data: Data
@@ -21,6 +23,29 @@ struct RequestSyncPacket {
     let sinceTimestamp: UInt64?
     let fragmentIdFilter: String?
 
+    /// Encodes 8-byte fragment stream IDs as the 0x06 filter string,
+    /// dropping malformed IDs and capping at `maxFragmentIdFilterCount`.
+    static func encodeFragmentIdFilter(_ fragmentIDs: [Data]) -> String? {
+        let tokens = fragmentIDs
+            .filter { $0.count == 8 }
+            .prefix(maxFragmentIdFilterCount)
+            .map { $0.hexEncodedString() }
+        guard !tokens.isEmpty else { return nil }
+        return tokens.joined(separator: ",")
+    }
+
+    /// Decodes a 0x06 filter string back into 8-byte fragment stream IDs,
+    /// ignoring malformed tokens and capping at `maxFragmentIdFilterCount`.
+    static func decodeFragmentIdFilter(_ filter: String?) -> Set<Data>? {
+        guard let filter else { return nil }
+        var ids: Set<Data> = []
+        for token in filter.split(separator: ",").prefix(maxFragmentIdFilterCount) {
+            guard token.count == 16, let id = Data(hexString: String(token)) else { continue }
+            ids.insert(id)
+        }
+        return ids.isEmpty ? nil : ids
+    }
+
     init(p: Int, m: UInt32, data: Data, types: SyncTypeFlags? = nil, sinceTimestamp: UInt64? = nil, fragmentIdFilter: String? = nil) {
         self.p = p
         self.m = m
@@ -97,7 +122,9 @@ struct RequestSyncPacket {
                     sinceTimestamp = ts
                 }
             case 0x06:
-                if let fid = String(data: v, encoding: .utf8) {
+                // Same acceptance cap as the GCS payload; an oversized filter
+                // is ignored rather than failing the whole request.
+                if v.count <= maxAcceptBytes, let fid = String(data: v, encoding: .utf8) {
                     fragmentIdFilter = fid
                 }
             default:

bitchat/Nostr/NostrPoW.swift

@@ -0,0 +1,215 @@
+import BitFoundation
+import CryptoKit
+import Foundation
+
+/// NIP-13 proof-of-work for Nostr events.
+///
+/// Outgoing kind-20000 geohash messages mine a `["nonce", "<value>", "<target>"]`
+/// tag so the event ID carries at least `target` leading zero bits. Inbound
+/// events are scored (never hard-rejected — the network has clients that do
+/// not mine): validated PoW at or above `rateLimitBypassBits` relaxes the
+/// per-sender public rate limit, everything else keeps the strict limits.
+enum NostrPoW {
+
+    // MARK: - Tuning
+
+    /// Difficulty (leading zero bits of the event ID) mined onto outgoing
+    /// geohash messages. 8 bits is ~256 hash attempts — typically well under
+    /// 100 ms on any supported device.
+    static let targetBits = 8
+
+    /// Inbound events whose validated NIP-13 difficulty is at least this many
+    /// bits skip the per-sender rate-limit bucket (the content-flood bucket
+    /// still applies). See `MessageRateLimiter.allow`.
+    static let rateLimitBypassBits = 8
+
+    /// Hard cap on mining wall-clock time. When it hits, the committed target
+    /// steps down until a difficulty reachable in a small extra budget is
+    /// found and the message is sent anyway — mining never blocks sending.
+    static let miningTimeCap: TimeInterval = 2.0
+
+    /// Budget for each stepped-down attempt after the main cap (or a task
+    /// cancellation) hits.
+    private static let fallbackTimeCap: TimeInterval = 0.15
+
+    /// The hot loop checks the deadline and task cancellation every this many
+    /// hash attempts.
+    private static let checkInterval: UInt64 = 1024
+
+    /// The nonce value is a fixed-width hex counter so the serialized event
+    /// template can be mutated in place without reallocation.
+    private static let nonceLength = 16
+
+    // MARK: - Scoring
+
+    /// Number of leading zero bits in a byte sequence (NIP-13 difficulty of
+    /// an event-ID hash).
+    static func leadingZeroBits<Bytes: Sequence<UInt8>>(_ bytes: Bytes) -> Int {
+        var total = 0
+        for byte in bytes {
+            if byte == 0 {
+                total += 8
+            } else {
+                total += byte.leadingZeroBitCount
+                break
+            }
+        }
+        return total
+    }
+
+    /// Validated NIP-13 difficulty of an inbound event.
+    ///
+    /// The committed target in the nonce tag is what counts: the actual
+    /// leading zero bits of the ID must meet it (otherwise the claim is void
+    /// and the event scores 0), and work beyond the commitment earns no extra
+    /// credit — this stops spammers who mine a low target from getting lucky
+    /// high scores. Events without a well-formed commitment score 0.
+    static func validatedDifficulty(idHex: String, tags: [[String]]) -> Int {
+        guard let nonceTag = tags.last(where: { $0.first == "nonce" }),
+              nonceTag.count >= 3,
+              let committed = Int(nonceTag[2]),
+              committed > 0, committed <= 256,
+              let idData = Data(hexString: idHex)
+        else {
+            return 0
+        }
+        return leadingZeroBits(idData) >= committed ? committed : 0
+    }
+
+    // MARK: - Mining
+
+    /// Mine a `["nonce", value, target]` tag for the given unsigned-event
+    /// fields. Nonisolated async: runs off the calling actor.
+    ///
+    /// Bounded by `miningTimeCap`: when the cap hits — or the surrounding
+    /// task is cancelled — the committed target steps down (halving to 0,
+    /// which any hash satisfies) so the event still ships promptly with an
+    /// honest commitment at the difficulty actually reached. Returns nil only
+    /// if canonical serialization fails; the caller then sends unmined.
+    static func mineNonceTag(
+        pubkey: String,
+        createdAt: Int,
+        kind: Int,
+        tags: [[String]],
+        content: String,
+        targetBits: Int = NostrPoW.targetBits
+    ) async -> [String]? {
+        var target = min(max(targetBits, 0), 256)
+        var budget = miningTimeCap
+        while true {
+            if let tag = mineAttempt(
+                pubkey: pubkey,
+                createdAt: createdAt,
+                kind: kind,
+                baseTags: tags,
+                content: content,
+                targetBits: target,
+                budget: budget
+            ) {
+                return tag
+            }
+            // Target 0 succeeds on the first hash, so reaching it with nil
+            // means serialization itself failed — give up on mining.
+            if target == 0 { return nil }
+            target /= 2
+            budget = fallbackTimeCap
+        }
+    }
+
+    /// One bounded mining pass at a fixed committed target. Allocation-light:
+    /// the canonical serialization is built once and only the fixed-width
+    /// nonce bytes are rewritten per attempt (the event ID is recomputed for
+    /// every attempt, per NIP-13). Returns nil on timeout/cancellation or if
+    /// the template could not be built.
+    private static func mineAttempt(
+        pubkey: String,
+        createdAt: Int,
+        kind: Int,
+        baseTags: [[String]],
+        content: String,
+        targetBits: Int,
+        budget: TimeInterval
+    ) -> [String]? {
+        let targetString = String(targetBits)
+        guard let template = serializedTemplate(
+            pubkey: pubkey,
+            createdAt: createdAt,
+            kind: kind,
+            baseTags: baseTags,
+            content: content,
+            targetString: targetString
+        ) else {
+            return nil
+        }
+        var buffer = template.buffer
+        let nonceRange = template.nonceRange
+
+        let deadline = DispatchTime.now().uptimeNanoseconds &+ UInt64(budget * 1_000_000_000)
+        let hexDigits = [UInt8]("0123456789abcdef".utf8)
+        var nonce = UInt64.random(in: .min ... .max)
+        var attempts: UInt64 = 0
+
+        while true {
+            // Write the nonce as 16 lowercase hex chars, in place.
+            var value = nonce
+            var index = nonceRange.upperBound
+            while index > nonceRange.lowerBound {
+                index -= 1
+                buffer[index] = hexDigits[Int(value & 0xF)]
+                value >>= 4
+            }
+
+            if leadingZeroBits(SHA256.hash(data: buffer)) >= targetBits {
+                // Identical to the bytes just written into the buffer.
+                return ["nonce", String(format: "%016llx", nonce), targetString]
+            }
+
+            nonce &+= 1
+            attempts &+= 1
+            if attempts % checkInterval == 0,
+               Task.isCancelled || DispatchTime.now().uptimeNanoseconds >= deadline {
+                return nil
+            }
+        }
+    }
+
+    /// Canonical NIP-01 serialization of the event with a placeholder nonce,
+    /// plus the byte range of the nonce value inside it.
+    ///
+    /// The range is located by serializing twice with two same-length
+    /// placeholders and diffing the buffers — the only differing bytes are
+    /// the nonce value, so this stays correct however `JSONSerialization`
+    /// escapes the surrounding fields (and even if the content contains the
+    /// placeholder text itself).
+    private static func serializedTemplate(
+        pubkey: String,
+        createdAt: Int,
+        kind: Int,
+        baseTags: [[String]],
+        content: String,
+        targetString: String
+    ) -> (buffer: Data, nonceRange: Range<Int>)? {
+        func serialize(noncePlaceholder: String) -> Data? {
+            var tags = baseTags
+            tags.append(["nonce", noncePlaceholder, targetString])
+            let serialized: [Any] = [0, pubkey, createdAt, kind, tags, content]
+            return try? JSONSerialization.data(withJSONObject: serialized, options: [.withoutEscapingSlashes])
+        }
+
+        guard let zeros = serialize(noncePlaceholder: String(repeating: "0", count: nonceLength)),
+              let effs = serialize(noncePlaceholder: String(repeating: "f", count: nonceLength)),
+              zeros.count == effs.count
+        else {
+            return nil
+        }
+
+        var firstDiff = -1
+        var lastDiff = -1
+        for index in 0..<zeros.count where zeros[index] != effs[index] {
+            if firstDiff < 0 { firstDiff = index }
+            lastDiff = index
+        }
+        guard firstDiff >= 0, lastDiff - firstDiff + 1 == nonceLength else { return nil }
+        return (zeros, firstDiff..<(firstDiff + nonceLength))
+    }
+}

bitchat/Nostr/NostrProtocol.swift

@@ -19,6 +19,7 @@ struct NostrProtocol {
         case giftWrap = 1059 // NIP-59 gift wrap
         case ephemeralEvent = 20000
         case geohashPresence = 20001
+        case deletion = 5 // NIP-09 event deletion request
     }
     
     /// Create a NIP-17 private message
@@ -170,6 +171,63 @@ struct NostrProtocol {
         nickname: String? = nil,
         teleported: Bool = false
     ) throws -> NostrEvent {
+        let event = NostrEvent(
+            pubkey: senderIdentity.publicKeyHex,
+            createdAt: Date(),
+            kind: .ephemeralEvent,
+            tags: ephemeralGeohashTags(geohash: geohash, nickname: nickname, teleported: teleported),
+            content: content
+        )
+        let schnorrKey = try senderIdentity.schnorrSigningKey()
+        return try event.sign(with: schnorrKey)
+    }
+
+    /// Create a kind-20000 geohash message carrying a NIP-13 proof-of-work
+    /// nonce tag (see `NostrPoW`). Mining runs off the calling actor and is
+    /// bounded by `NostrPoW.miningTimeCap`; when the cap hits (or the
+    /// surrounding task is cancelled) the event ships at the highest
+    /// committed difficulty still met, and if mining is impossible it ships
+    /// unmined — sending is never blocked.
+    static func createMinedEphemeralGeohashEvent(
+        content: String,
+        geohash: String,
+        senderIdentity: NostrIdentity,
+        nickname: String? = nil,
+        teleported: Bool = false,
+        powTargetBits: Int = NostrPoW.targetBits
+    ) async throws -> NostrEvent {
+        var tags = ephemeralGeohashTags(geohash: geohash, nickname: nickname, teleported: teleported)
+        // Fix created_at up front: the mined nonce commits to the full
+        // serialized event, so the signed event must reuse the exact value.
+        let createdAt = Int(Date().timeIntervalSince1970)
+        if let nonceTag = await NostrPoW.mineNonceTag(
+            pubkey: senderIdentity.publicKeyHex,
+            createdAt: createdAt,
+            kind: EventKind.ephemeralEvent.rawValue,
+            tags: tags,
+            content: content,
+            targetBits: powTargetBits
+        ) {
+            tags.append(nonceTag)
+        }
+        let event = NostrEvent(
+            pubkey: senderIdentity.publicKeyHex,
+            createdAt: Date(timeIntervalSince1970: TimeInterval(createdAt)),
+            kind: .ephemeralEvent,
+            tags: tags,
+            content: content
+        )
+        let schnorrKey = try senderIdentity.schnorrSigningKey()
+        return try event.sign(with: schnorrKey)
+    }
+
+    /// Tags for a kind-20000 geohash message (shared by the plain and mined
+    /// variants).
+    private static func ephemeralGeohashTags(
+        geohash: String,
+        nickname: String?,
+        teleported: Bool
+    ) -> [[String]] {
         var tags = [["g", geohash]]
         if let nickname = nickname?.trimmedOrNilIfEmpty {
             tags.append(["n", nickname])
@@ -177,15 +235,7 @@ struct NostrProtocol {
         if teleported {
             tags.append(["t", "teleport"])
         }
-        let event = NostrEvent(
-            pubkey: senderIdentity.publicKeyHex,
-            createdAt: Date(),
-            kind: .ephemeralEvent,
-            tags: tags,
-            content: content
-        )
-        let schnorrKey = try senderIdentity.schnorrSigningKey()
-        return try event.sign(with: schnorrKey)
+        return tags
     }
 
     /// Create a geohash presence heartbeat (kind 20001)
@@ -207,16 +257,22 @@ struct NostrProtocol {
     }
 
     /// Create a persistent location note (kind 1: text note) tagged to a street-level geohash.
+    /// An optional `expiresAt` adds a NIP-40 expiration tag so honoring relays
+    /// drop the note in step with a bridged board post's expiry.
     static func createGeohashTextNote(
         content: String,
         geohash: String,
         senderIdentity: NostrIdentity,
-        nickname: String? = nil
+        nickname: String? = nil,
+        expiresAt: Date? = nil
     ) throws -> NostrEvent {
         var tags = [["g", geohash]]
         if let nickname = nickname?.trimmedOrNilIfEmpty {
             tags.append(["n", nickname])
         }
+        if let expiresAt {
+            tags.append(["expiration", String(Int(expiresAt.timeIntervalSince1970))])
+        }
         let event = NostrEvent(
             pubkey: senderIdentity.publicKeyHex,
             createdAt: Date(),
@@ -227,7 +283,25 @@ struct NostrProtocol {
         let schnorrKey = try senderIdentity.schnorrSigningKey()
         return try event.sign(with: schnorrKey)
     }
-    
+
+    /// Create a NIP-09 deletion request for one of our own events. Relays that
+    /// honor NIP-09 drop the referenced event; it must be signed by the same
+    /// key that signed the original.
+    static func createDeleteEvent(
+        ofEventID eventID: String,
+        senderIdentity: NostrIdentity
+    ) throws -> NostrEvent {
+        let event = NostrEvent(
+            pubkey: senderIdentity.publicKeyHex,
+            createdAt: Date(),
+            kind: .deletion,
+            tags: [["e", eventID]],
+            content: ""
+        )
+        let schnorrKey = try senderIdentity.schnorrSigningKey()
+        return try event.sign(with: schnorrKey)
+    }
+
     // MARK: - Private Methods
     
     private static func createSeal(

bitchat/Protocols/BitchatProtocol.swift

@@ -18,7 +18,7 @@
 /// - Efficient binary message encoding
 /// - Message fragmentation for large payloads
 /// - TTL-based routing for mesh networks
-/// - Privacy features like padding and timing obfuscation
+/// - Privacy features: message padding and randomized relay jitter
 /// - Integration points for end-to-end encryption
 ///
 /// ## Protocol Design
@@ -38,18 +38,20 @@
 /// 7. **Decoding**: Binary data parsed back to message objects
 ///
 /// ## Security Considerations
-/// - Message padding obscures actual content length
-/// - Timing obfuscation prevents traffic analysis
+/// - Message padding (to 256/512/1024/2048-byte blocks) obscures actual content length
+/// - Randomized relay jitter reduces the traffic-analysis signal; there is no
+///   cover traffic or per-message timing obfuscation
 /// - Integration with Noise Protocol for E2E encryption
 /// - No persistent identifiers in protocol headers
 ///
 /// ## Message Types
 /// - **Announce/Leave**: Peer presence notifications
-/// - **Message**: User chat messages (broadcast or directed)
+/// - **Message**: Public chat messages
 /// - **Fragment**: Multi-part message handling
-/// - **Delivery/Read**: Message acknowledgments
-/// - **Noise**: Encrypted channel establishment
-/// - **Version**: Protocol version negotiation
+/// - **NoiseHandshake/NoiseEncrypted**: Encrypted channel establishment and
+///   all private payloads (messages, delivery acks, read receipts)
+/// - **CourierEnvelope**: Sealed store-and-forward mail
+/// - **RequestSync/FileTransfer**: Gossip history sync and media transfer
 ///
 /// ## Future Extensions
 /// The protocol is designed to be extensible:
@@ -72,17 +74,25 @@ enum NoisePayloadType: UInt8 {
     case privateMessage = 0x01      // Private chat message
     case readReceipt = 0x02         // Message was read
     case delivered = 0x03           // Message was delivered
+    // Private groups (0x04/0x05 reserved by other features)
+    case groupInvite = 0x06         // Creator-signed group state (invite)
+    case groupKeyUpdate = 0x07      // Creator-signed group state (key rotation / roster update)
     // Verification (QR-based OOB binding)
     case verifyChallenge = 0x10     // Verification challenge
     case verifyResponse  = 0x11     // Verification response
-    
+    // Transitive verification (web of trust)
+    case vouch = 0x12               // Batch of vouch attestations
+
     var description: String {
         switch self {
         case .privateMessage: return "privateMessage"
         case .readReceipt: return "readReceipt"
         case .delivered: return "delivered"
+        case .groupInvite: return "groupInvite"
+        case .groupKeyUpdate: return "groupKeyUpdate"
         case .verifyChallenge: return "verifyChallenge"
         case .verifyResponse: return "verifyResponse"
+        case .vouch: return "vouch"
         }
     }
 }
@@ -114,6 +124,9 @@ protocol BitchatDelegate: AnyObject {
     // Low-level events for better separation of concerns
     func didReceiveNoisePayload(from peerID: PeerID, type: NoisePayloadType, payload: Data, timestamp: Date)
 
+    // Encrypted group broadcast (opaque envelope; decrypted by the group coordinator)
+    func didReceiveGroupMessage(payload: Data, timestamp: Date)
+
     // Bluetooth state updates for user notifications
     func didUpdateBluetoothState(_ state: CBManagerState)
     func didReceivePublicMessage(from peerID: PeerID, nickname: String, content: String, timestamp: Date, messageID: String?)
@@ -133,6 +146,10 @@ extension BitchatDelegate {
         // Default empty implementation
     }
 
+    func didReceiveGroupMessage(payload: Data, timestamp: Date) {
+        // Default empty implementation
+    }
+
     func didReceivePublicMessage(from peerID: PeerID, nickname: String, content: String, timestamp: Date, messageID: String?) {
         // Default empty implementation
     }

bitchat/Protocols/BoardPackets.swift

@@ -0,0 +1,348 @@
+//
+// BoardPackets.swift
+// bitchat
+//
+// This is free and unencumbered software released into the public domain.
+// For more information, see <https://unlicense.org>
+//
+
+import CryptoKit
+import Foundation
+
+// MARK: - Board wire format (MessageType.boardPost payloads)
+//
+// TLV layout (type u8, length u16 big-endian, value), matching REQUEST_SYNC:
+//  - 0x01: kind (u8) — 0x01 post, 0x02 tombstone
+//  - 0x02: postID (16B random)
+//  - 0x03: geohash (UTF-8, empty = mesh-local board, max 12 chars)
+//  - 0x04: content (UTF-8, 1...512 bytes) [post]
+//  - 0x05: authorSigningKey (32B Ed25519 public key)
+//  - 0x06: authorNickname (UTF-8, max 64 bytes)
+//  - 0x07: createdAt (u64 big-endian, ms) [post]
+//  - 0x08: expiresAt (u64 big-endian, ms, max 7 days after createdAt) [post]
+//  - 0x09: flags (u8, bit0 = urgent) [post]
+//  - 0x0A: signature (64B Ed25519)
+//  - 0x0B: deletedAt (u64 big-endian, ms) [tombstone]
+// Unknown TLVs are skipped for forward compatibility.
+
+enum BoardWireConstants {
+    static let postIDLength = 16
+    static let signingKeyLength = 32
+    static let signatureLength = 64
+    static let contentMaxBytes = 512
+    static let nicknameMaxBytes = 64
+    static let geohashMaxLength = 12
+    /// Posts may live at most 7 days past their creation timestamp.
+    static let maxLifetimeMs: UInt64 = 7 * 24 * 60 * 60 * 1000
+    static let postSigningContext = "bitchat-board-v1"
+    static let tombstoneSigningContext = "bitchat-board-del-v1"
+    static let geohashAlphabet = Set("0123456789bcdefghjkmnpqrstuvwxyz")
+}
+
+private enum BoardTLVType: UInt8 {
+    case kind = 0x01
+    case postID = 0x02
+    case geohash = 0x03
+    case content = 0x04
+    case authorSigningKey = 0x05
+    case authorNickname = 0x06
+    case createdAt = 0x07
+    case expiresAt = 0x08
+    case flags = 0x09
+    case signature = 0x0A
+    case deletedAt = 0x0B
+}
+
+private enum BoardWireKind: UInt8 {
+    case post = 0x01
+    case tombstone = 0x02
+}
+
+/// A signed, persistent bulletin-board notice.
+struct BoardPostPacket: Equatable {
+    let postID: Data
+    /// Empty string scopes the post to the mesh-local board.
+    let geohash: String
+    let content: String
+    let authorSigningKey: Data
+    let authorNickname: String
+    let createdAt: UInt64
+    let expiresAt: UInt64
+    let flags: UInt8
+    let signature: Data
+
+    static let urgentFlag: UInt8 = 0x01
+
+    var isUrgent: Bool { flags & Self.urgentFlag != 0 }
+
+    /// Canonical bytes covered by the Ed25519 signature. Variable-length
+    /// fields are length-prefixed so no two field combinations can collide.
+    static func signingBytes(
+        postID: Data,
+        geohash: String,
+        content: String,
+        authorSigningKey: Data,
+        authorNickname: String,
+        createdAt: UInt64,
+        expiresAt: UInt64,
+        flags: UInt8
+    ) -> Data {
+        var out = Data()
+        BoardWireEncoding.appendContext(BoardWireConstants.postSigningContext, to: &out)
+        out.append(postID)
+        BoardWireEncoding.appendLengthPrefixed(Data(geohash.utf8), to: &out)
+        BoardWireEncoding.appendLengthPrefixed(Data(content.utf8), to: &out)
+        out.append(authorSigningKey)
+        BoardWireEncoding.appendLengthPrefixed(Data(authorNickname.utf8), to: &out)
+        BoardWireEncoding.appendUInt64(createdAt, to: &out)
+        BoardWireEncoding.appendUInt64(expiresAt, to: &out)
+        out.append(flags)
+        return out
+    }
+
+    var signingBytes: Data {
+        Self.signingBytes(
+            postID: postID,
+            geohash: geohash,
+            content: content,
+            authorSigningKey: authorSigningKey,
+            authorNickname: authorNickname,
+            createdAt: createdAt,
+            expiresAt: expiresAt,
+            flags: flags
+        )
+    }
+
+    func verifySignature() -> Bool {
+        BoardWireEncoding.verify(signature: signature, over: signingBytes, publicKey: authorSigningKey)
+    }
+}
+
+/// A signed deletion marker. Only the author's key can produce one; receivers
+/// keep it until the post's original expiry so the delete outruns the post.
+struct BoardTombstonePacket: Equatable {
+    let postID: Data
+    let authorSigningKey: Data
+    let deletedAt: UInt64
+    let signature: Data
+
+    static func signingBytes(postID: Data, deletedAt: UInt64) -> Data {
+        var out = Data()
+        BoardWireEncoding.appendContext(BoardWireConstants.tombstoneSigningContext, to: &out)
+        out.append(postID)
+        BoardWireEncoding.appendUInt64(deletedAt, to: &out)
+        return out
+    }
+
+    var signingBytes: Data {
+        Self.signingBytes(postID: postID, deletedAt: deletedAt)
+    }
+
+    func verifySignature() -> Bool {
+        BoardWireEncoding.verify(signature: signature, over: signingBytes, publicKey: authorSigningKey)
+    }
+}
+
+/// Decoded board payload: either a live post or a tombstone.
+enum BoardWire: Equatable {
+    case post(BoardPostPacket)
+    case tombstone(BoardTombstonePacket)
+
+    func encode() -> Data {
+        var out = Data()
+        func putTLV(_ t: BoardTLVType, _ v: Data) {
+            out.append(t.rawValue)
+            let len = UInt16(v.count)
+            out.append(UInt8((len >> 8) & 0xFF))
+            out.append(UInt8(len & 0xFF))
+            out.append(v)
+        }
+        switch self {
+        case .post(let post):
+            putTLV(.kind, Data([BoardWireKind.post.rawValue]))
+            putTLV(.postID, post.postID)
+            putTLV(.geohash, Data(post.geohash.utf8))
+            putTLV(.content, Data(post.content.utf8))
+            putTLV(.authorSigningKey, post.authorSigningKey)
+            putTLV(.authorNickname, Data(post.authorNickname.utf8))
+            putTLV(.createdAt, BoardWireEncoding.uint64Data(post.createdAt))
+            putTLV(.expiresAt, BoardWireEncoding.uint64Data(post.expiresAt))
+            putTLV(.flags, Data([post.flags]))
+            putTLV(.signature, post.signature)
+        case .tombstone(let tombstone):
+            putTLV(.kind, Data([BoardWireKind.tombstone.rawValue]))
+            putTLV(.postID, tombstone.postID)
+            putTLV(.authorSigningKey, tombstone.authorSigningKey)
+            putTLV(.deletedAt, BoardWireEncoding.uint64Data(tombstone.deletedAt))
+            putTLV(.signature, tombstone.signature)
+        }
+        return out
+    }
+
+    /// Structural decode; the caller must still verify the signature before
+    /// ingesting (`verifySignature()`).
+    static func decode(from data: Data) -> BoardWire? {
+        var off = data.startIndex
+        var kind: BoardWireKind?
+        var postID: Data?
+        var geohash: String?
+        var content: String?
+        var contentBytes = 0
+        var authorSigningKey: Data?
+        var authorNickname: String?
+        var nicknameBytes = 0
+        var createdAt: UInt64?
+        var expiresAt: UInt64?
+        var flags: UInt8?
+        var signature: Data?
+        var deletedAt: UInt64?
+
+        while off + 3 <= data.endIndex {
+            let t = data[off]; off += 1
+            let len = (Int(data[off]) << 8) | Int(data[off + 1]); off += 2
+            guard off + len <= data.endIndex else { return nil }
+            let v = data.subdata(in: off..<(off + len)); off += len
+            switch BoardTLVType(rawValue: t) {
+            case .kind:
+                guard v.count == 1 else { return nil }
+                kind = BoardWireKind(rawValue: v[v.startIndex])
+            case .postID:
+                guard v.count == BoardWireConstants.postIDLength else { return nil }
+                postID = v
+            case .geohash:
+                guard v.count <= BoardWireConstants.geohashMaxLength else { return nil }
+                geohash = String(data: v, encoding: .utf8)
+            case .content:
+                guard v.count <= BoardWireConstants.contentMaxBytes else { return nil }
+                contentBytes = v.count
+                content = String(data: v, encoding: .utf8)
+            case .authorSigningKey:
+                guard v.count == BoardWireConstants.signingKeyLength else { return nil }
+                authorSigningKey = v
+            case .authorNickname:
+                guard v.count <= BoardWireConstants.nicknameMaxBytes else { return nil }
+                nicknameBytes = v.count
+                authorNickname = String(data: v, encoding: .utf8)
+            case .createdAt:
+                createdAt = BoardWireEncoding.uint64(from: v)
+            case .expiresAt:
+                expiresAt = BoardWireEncoding.uint64(from: v)
+            case .flags:
+                guard v.count == 1 else { return nil }
+                flags = v[v.startIndex]
+            case .signature:
+                guard v.count == BoardWireConstants.signatureLength else { return nil }
+                signature = v
+            case .deletedAt:
+                deletedAt = BoardWireEncoding.uint64(from: v)
+            case nil:
+                continue // forward compatible; ignore unknown TLVs
+            }
+        }
+
+        guard let postID, let authorSigningKey, let signature else { return nil }
+
+        switch kind {
+        case .post:
+            guard let geohash, let content, let authorNickname,
+                  let createdAt, let expiresAt, let flags,
+                  contentBytes >= 1,
+                  nicknameBytes <= BoardWireConstants.nicknameMaxBytes,
+                  isValidGeohashField(geohash),
+                  expiresAt > createdAt,
+                  expiresAt - createdAt <= BoardWireConstants.maxLifetimeMs else {
+                return nil
+            }
+            return .post(BoardPostPacket(
+                postID: postID,
+                geohash: geohash,
+                content: content,
+                authorSigningKey: authorSigningKey,
+                authorNickname: authorNickname,
+                createdAt: createdAt,
+                expiresAt: expiresAt,
+                flags: flags,
+                signature: signature
+            ))
+        case .tombstone:
+            guard let deletedAt else { return nil }
+            return .tombstone(BoardTombstonePacket(
+                postID: postID,
+                authorSigningKey: authorSigningKey,
+                deletedAt: deletedAt,
+                signature: signature
+            ))
+        case nil:
+            return nil
+        }
+    }
+
+    func verifySignature() -> Bool {
+        switch self {
+        case .post(let post): return post.verifySignature()
+        case .tombstone(let tombstone): return tombstone.verifySignature()
+        }
+    }
+
+    /// Cheap TLV peek for relay policy: is this payload an urgent post?
+    /// Avoids a full decode on the hot relay path.
+    static func urgentFlag(in data: Data) -> Bool {
+        var off = data.startIndex
+        while off + 3 <= data.endIndex {
+            let t = data[off]; off += 1
+            let len = (Int(data[off]) << 8) | Int(data[off + 1]); off += 2
+            guard off + len <= data.endIndex else { return false }
+            if t == BoardTLVType.flags.rawValue, len == 1 {
+                return data[off] & BoardPostPacket.urgentFlag != 0
+            }
+            off += len
+        }
+        return false
+    }
+
+    /// Empty geohash = mesh-local board; otherwise 1-12 chars of the geohash
+    /// base32 alphabet.
+    private static func isValidGeohashField(_ geohash: String) -> Bool {
+        geohash.isEmpty || geohash.allSatisfy { BoardWireConstants.geohashAlphabet.contains($0) }
+    }
+}
+
+enum BoardWireEncoding {
+    static func appendContext(_ context: String, to out: inout Data) {
+        let bytes = Data(context.utf8)
+        out.append(UInt8(min(bytes.count, 255)))
+        out.append(bytes.prefix(255))
+    }
+
+    static func appendLengthPrefixed(_ value: Data, to out: inout Data) {
+        let len = UInt16(min(value.count, Int(UInt16.max)))
+        out.append(UInt8((len >> 8) & 0xFF))
+        out.append(UInt8(len & 0xFF))
+        out.append(value.prefix(Int(UInt16.max)))
+    }
+
+    static func appendUInt64(_ value: UInt64, to out: inout Data) {
+        var be = value.bigEndian
+        withUnsafeBytes(of: &be) { out.append(contentsOf: $0) }
+    }
+
+    static func uint64Data(_ value: UInt64) -> Data {
+        var out = Data()
+        appendUInt64(value, to: &out)
+        return out
+    }
+
+    static func uint64(from data: Data) -> UInt64? {
+        guard data.count == 8 else { return nil }
+        var value: UInt64 = 0
+        for byte in data { value = (value << 8) | UInt64(byte) }
+        return value
+    }
+
+    static func verify(signature: Data, over message: Data, publicKey: Data) -> Bool {
+        guard let key = try? Curve25519.Signing.PublicKey(rawRepresentation: publicKey) else {
+            return false
+        }
+        return key.isValidSignature(signature, for: message)
+    }
+}

bitchat/Protocols/Geohash.swift

@@ -18,6 +18,14 @@ enum Geohash {
         return geohash.lowercased().allSatisfy { base32Map[$0] != nil }
     }
 
+    /// Validates a geohash string at any channel precision (1-12 characters).
+    /// - Parameter geohash: The geohash string to validate
+    /// - Returns: true if a non-empty base32 geohash of at most 12 characters
+    static func isValidGeohash(_ geohash: String) -> Bool {
+        guard (1...12).contains(geohash.count) else { return false }
+        return geohash.lowercased().allSatisfy { base32Map[$0] != nil }
+    }
+
     /// Encodes the provided coordinates into a geohash string.
     /// - Parameters:
     ///   - latitude: Latitude in degrees (-90...90)

bitchat/Protocols/NostrCarrierPacket.swift

@@ -0,0 +1,136 @@
+//
+// NostrCarrierPacket.swift
+// bitchat
+//
+// This is free and unencumbered software released into the public domain.
+// For more information, see <https://unlicense.org>
+//
+
+import BitFoundation
+import Foundation
+
+/// Wire payload for `MessageType.nostrCarrier` (0x28): a complete, signed
+/// Nostr event ferried over the mesh between a mesh-only peer and an
+/// internet gateway peer.
+///
+/// - `toGateway` rides a DIRECTED packet (recipientID = the gateway peer):
+///   a mesh-only sender asks the gateway to publish its locally signed
+///   geohash event to Nostr relays.
+/// - `fromGateway` rides a BROADCAST packet (default TTL): the gateway
+///   rebroadcasts inbound relay events so mesh-only peers see the channel.
+///
+/// The carried event is public geohash chat — already plaintext on Nostr —
+/// so the carrier adds no encryption. It IS signed by the originator's
+/// per-geohash identity, so neither the gateway nor any mesh relay can forge
+/// or alter it undetected: gateways and receivers verify the Schnorr
+/// signature before acting on it.
+///
+/// TLV encoding with 2-byte big-endian lengths (the event JSON exceeds the
+/// 1-byte TLV range used by smaller packets). Unknown TLV types are skipped
+/// for forward compatibility.
+struct NostrCarrierPacket: Equatable {
+    enum Direction: UInt8 {
+        case toGateway = 0x01
+        case fromGateway = 0x02
+    }
+
+    let direction: Direction
+    let geohash: String
+    /// Complete signed Nostr event JSON (id, pubkey, created_at, kind, tags,
+    /// content, sig).
+    let eventJSON: Data
+
+    /// BLE airtime cap for a carried event.
+    static let maxEventJSONBytes = 16 * 1024
+    static let maxGeohashLength = 12
+
+    private enum TLVType: UInt8 {
+        case direction = 0x01
+        case geohash = 0x02
+        case eventJSON = 0x03
+    }
+
+    init?(direction: Direction, geohash: String, eventJSON: Data) {
+        let geohashBytes = Data(geohash.utf8)
+        guard !geohashBytes.isEmpty,
+              geohashBytes.count <= Self.maxGeohashLength,
+              !eventJSON.isEmpty,
+              eventJSON.count <= Self.maxEventJSONBytes else {
+            return nil
+        }
+        self.direction = direction
+        self.geohash = geohash
+        self.eventJSON = eventJSON
+    }
+
+    init?(direction: Direction, geohash: String, event: NostrEvent) {
+        guard let json = try? event.jsonString(), !json.isEmpty else { return nil }
+        self.init(direction: direction, geohash: geohash, eventJSON: Data(json.utf8))
+    }
+
+    /// Decodes the carried event. Callers MUST still verify
+    /// `event.isValidSignature()` before publishing or displaying it.
+    func event() -> NostrEvent? {
+        guard let dict = try? JSONSerialization.jsonObject(with: eventJSON) as? [String: Any] else {
+            return nil
+        }
+        return try? NostrEvent(from: dict)
+    }
+
+    func encode() -> Data? {
+        var data = Data()
+        data.reserveCapacity(eventJSON.count + geohash.utf8.count + 12)
+
+        func appendTLV(_ type: TLVType, _ value: Data) {
+            data.append(type.rawValue)
+            data.append(UInt8((value.count >> 8) & 0xFF))
+            data.append(UInt8(value.count & 0xFF))
+            data.append(value)
+        }
+
+        appendTLV(.direction, Data([direction.rawValue]))
+        appendTLV(.geohash, Data(geohash.utf8))
+        appendTLV(.eventJSON, eventJSON)
+        return data
+    }
+
+    static func decode(_ data: Data) -> NostrCarrierPacket? {
+        // Defensive slice re-base (Data slices keep parent indices).
+        let data = Data(data)
+        var offset = 0
+        var direction: Direction?
+        var geohash: String?
+        var eventJSON: Data?
+
+        while offset + 3 <= data.count {
+            let typeRaw = data[offset]
+            let length = (Int(data[offset + 1]) << 8) | Int(data[offset + 2])
+            offset += 3
+            guard offset + length <= data.count else { return nil }
+            let value = data.subdata(in: offset..<offset + length)
+            offset += length
+
+            switch TLVType(rawValue: typeRaw) {
+            case .direction:
+                guard value.count == 1, let parsed = Direction(rawValue: value[0]) else { return nil }
+                direction = parsed
+            case .geohash:
+                guard let parsed = String(data: value, encoding: .utf8) else { return nil }
+                geohash = parsed
+            case .eventJSON:
+                eventJSON = value
+            case nil:
+                // Unknown TLV; skip (tolerant decoder for forward compatibility).
+                continue
+            }
+        }
+
+        guard offset == data.count,
+              let direction,
+              let geohash,
+              let eventJSON else {
+            return nil
+        }
+        return NostrCarrierPacket(direction: direction, geohash: geohash, eventJSON: eventJSON)
+    }
+}

bitchat/Protocols/Packets.swift

@@ -1,3 +1,4 @@
+import BitFoundation
 import Foundation
 
 // MARK: - Protocol TLV Packets
@@ -7,12 +8,28 @@ struct AnnouncementPacket {
     let noisePublicKey: Data            // Noise static public key (Curve25519.KeyAgreement)
     let signingPublicKey: Data          // Ed25519 public key for signing
     let directNeighbors: [Data]?        // 8-byte peer IDs
+    let capabilities: PeerCapabilities? // advertised feature bits; nil when absent (old clients)
+
+    init(
+        nickname: String,
+        noisePublicKey: Data,
+        signingPublicKey: Data,
+        directNeighbors: [Data]?,
+        capabilities: PeerCapabilities? = nil
+    ) {
+        self.nickname = nickname
+        self.noisePublicKey = noisePublicKey
+        self.signingPublicKey = signingPublicKey
+        self.directNeighbors = directNeighbors
+        self.capabilities = capabilities
+    }
 
     private enum TLVType: UInt8 {
         case nickname = 0x01
         case noisePublicKey = 0x02
         case signingPublicKey = 0x03
         case directNeighbors = 0x04
+        case capabilities = 0x05
     }
 
     func encode() -> Data? {
@@ -48,6 +65,15 @@ struct AnnouncementPacket {
             }
         }
 
+        // TLV for capabilities (optional)
+        if let capabilities = capabilities {
+            let capabilityBytes = capabilities.encoded()
+            guard capabilityBytes.count <= 255 else { return nil }
+            data.append(TLVType.capabilities.rawValue)
+            data.append(UInt8(capabilityBytes.count))
+            data.append(capabilityBytes)
+        }
+
         return data
     }
 
@@ -57,6 +83,7 @@ struct AnnouncementPacket {
         var noisePublicKey: Data?
         var signingPublicKey: Data?
         var directNeighbors: [Data]?
+        var capabilities: PeerCapabilities?
 
         while offset + 2 <= data.count {
             let typeRaw = data[offset]
@@ -87,6 +114,8 @@ struct AnnouncementPacket {
                         }
                         directNeighbors = neighbors
                     }
+                case .capabilities:
+                    capabilities = PeerCapabilities(encoded: Data(value))
                 }
             } else {
                 // Unknown TLV; skip (tolerant decoder for forward compatibility)
@@ -99,7 +128,8 @@ struct AnnouncementPacket {
             nickname: nickname,
             noisePublicKey: noisePublicKey,
             signingPublicKey: signingPublicKey,
-            directNeighbors: directNeighbors
+            directNeighbors: directNeighbors,
+            capabilities: capabilities
         )
     }
 }

bitchat/Protocols/PeerCapabilities+Local.swift

@@ -0,0 +1,7 @@
+import BitFoundation
+
+extension PeerCapabilities {
+    /// Capabilities this build advertises in its announce packets.
+    /// Each feature adds its bit here when it ships.
+    static let localSupported: PeerCapabilities = [.vouch, .prekeys, .groups]
+}

bitchat/Protocols/VouchAttestation.swift

@@ -0,0 +1,225 @@
+//
+// VouchAttestation.swift
+// bitchat
+//
+// This is free and unencumbered software released into the public domain.
+// For more information, see <https://unlicense.org>
+//
+
+import CryptoKit
+import Foundation
+
+/// A signed statement that the *sender of the enclosing Noise payload* has
+/// verified the identity described here ("transitive verification").
+///
+/// The voucher's identity is deliberately implicit: attestations only travel
+/// inside an authenticated Noise session (`NoisePayloadType.vouch`), so the
+/// receiver verifies the Ed25519 signature against the session peer's
+/// announce-bound signing key and stores the vouch keyed by that peer's
+/// fingerprint. Nothing in the attestation names the voucher, so a captured
+/// attestation cannot be replayed by a third party whose signing key doesn't
+/// match.
+///
+/// Wire format — single attestation (TLV, 1-byte type + 1-byte length):
+/// - `0x01` voucheeFingerprint: 32 bytes, SHA-256 of the vouchee's Noise static key
+/// - `0x02` voucheeSigningKey: 32 bytes, Ed25519; anchors the vouch to a concrete identity
+/// - `0x03` timestamp: 8 bytes big-endian, milliseconds since 1970
+/// - `0x04` signature: 64 bytes, Ed25519 by the VOUCHER's signing key over
+///   `"bitchat-vouch-v1" | voucheeFingerprint | voucheeSigningKey | timestamp`
+///
+/// Unknown TLV types are skipped for forward compatibility.
+///
+/// Batch format (the `vouch` Noise payload body):
+/// `[count: UInt8]` then per attestation `[length: UInt16 BE][attestation TLV]`.
+struct VouchAttestation: Equatable {
+    static let signingContext = "bitchat-vouch-v1"
+    /// Receiver-side expiry for attestations.
+    static let maxAge: TimeInterval = 30 * 24 * 60 * 60
+    /// Tolerated clock skew for attestations timestamped in the future.
+    static let maxClockSkew: TimeInterval = 60 * 60
+    /// Upper bound of attestations carried/accepted in one batch payload.
+    static let maxBatchCount = 16
+
+    static let fingerprintSize = 32
+    static let signingKeySize = 32
+    static let signatureSize = 64
+
+    let voucheeFingerprint: Data  // 32 bytes
+    let voucheeSigningKey: Data   // 32 bytes
+    let timestampMs: UInt64
+    let signature: Data           // 64 bytes
+
+    private enum TLVType: UInt8 {
+        case voucheeFingerprint = 0x01
+        case voucheeSigningKey = 0x02
+        case timestamp = 0x03
+        case signature = 0x04
+    }
+
+    var voucheeFingerprintHex: String { voucheeFingerprint.hexEncodedString() }
+
+    var timestamp: Date { Date(timeIntervalSince1970: TimeInterval(timestampMs) / 1000) }
+
+    /// The exact bytes the voucher signs.
+    static func signableBytes(
+        voucheeFingerprint: Data,
+        voucheeSigningKey: Data,
+        timestampMs: UInt64
+    ) -> Data {
+        var message = Data(signingContext.utf8)
+        message.append(voucheeFingerprint)
+        message.append(voucheeSigningKey)
+        var timestampBE = timestampMs.bigEndian
+        withUnsafeBytes(of: &timestampBE) { message.append(contentsOf: $0) }
+        return message
+    }
+
+    var signableBytes: Data {
+        Self.signableBytes(
+            voucheeFingerprint: voucheeFingerprint,
+            voucheeSigningKey: voucheeSigningKey,
+            timestampMs: timestampMs
+        )
+    }
+
+    /// Builds and signs an attestation. `sign` is the voucher's Ed25519
+    /// signing primitive (e.g. `Transport.noiseSignData`).
+    static func build(
+        voucheeFingerprint: Data,
+        voucheeSigningKey: Data,
+        timestampMs: UInt64 = UInt64(Date().timeIntervalSince1970 * 1000),
+        sign: (Data) -> Data?
+    ) -> VouchAttestation? {
+        guard voucheeFingerprint.count == fingerprintSize,
+              voucheeSigningKey.count == signingKeySize else { return nil }
+        let message = signableBytes(
+            voucheeFingerprint: voucheeFingerprint,
+            voucheeSigningKey: voucheeSigningKey,
+            timestampMs: timestampMs
+        )
+        guard let signature = sign(message), signature.count == signatureSize else { return nil }
+        return VouchAttestation(
+            voucheeFingerprint: voucheeFingerprint,
+            voucheeSigningKey: voucheeSigningKey,
+            timestampMs: timestampMs,
+            signature: signature
+        )
+    }
+
+    /// Verifies the Ed25519 signature against the voucher's announce-bound
+    /// signing key.
+    func verifySignature(voucherSigningKey: Data) -> Bool {
+        guard let publicKey = try? Curve25519.Signing.PublicKey(rawRepresentation: voucherSigningKey) else {
+            return false
+        }
+        return publicKey.isValidSignature(signature, for: signableBytes)
+    }
+
+    /// Whether the attestation is outside its validity window (older than
+    /// `maxAge`, or timestamped implausibly far in the future).
+    func isExpired(now: Date = Date()) -> Bool {
+        let age = now.timeIntervalSince(timestamp)
+        return age > Self.maxAge || age < -Self.maxClockSkew
+    }
+
+    // MARK: - Encoding
+
+    func encode() -> Data? {
+        guard voucheeFingerprint.count == Self.fingerprintSize,
+              voucheeSigningKey.count == Self.signingKeySize,
+              signature.count == Self.signatureSize else { return nil }
+        var data = Data()
+        func appendTLV(_ type: TLVType, _ value: Data) {
+            data.append(type.rawValue)
+            data.append(UInt8(value.count))
+            data.append(value)
+        }
+        appendTLV(.voucheeFingerprint, voucheeFingerprint)
+        appendTLV(.voucheeSigningKey, voucheeSigningKey)
+        var timestampBE = timestampMs.bigEndian
+        appendTLV(.timestamp, withUnsafeBytes(of: &timestampBE) { Data($0) })
+        appendTLV(.signature, signature)
+        return data
+    }
+
+    static func decode(from data: Data) -> VouchAttestation? {
+        var fingerprint: Data?
+        var signingKey: Data?
+        var timestampMs: UInt64?
+        var signature: Data?
+
+        var offset = data.startIndex
+        while offset < data.endIndex {
+            guard data.index(offset, offsetBy: 2, limitedBy: data.endIndex) != nil,
+                  offset + 1 < data.endIndex else { return nil }
+            let type = data[offset]
+            let length = Int(data[offset + 1])
+            let valueStart = offset + 2
+            guard let valueEnd = data.index(valueStart, offsetBy: length, limitedBy: data.endIndex) else {
+                return nil
+            }
+            let value = Data(data[valueStart..<valueEnd])
+            switch TLVType(rawValue: type) {
+            case .voucheeFingerprint:
+                guard value.count == fingerprintSize else { return nil }
+                fingerprint = value
+            case .voucheeSigningKey:
+                guard value.count == signingKeySize else { return nil }
+                signingKey = value
+            case .timestamp:
+                guard value.count == 8 else { return nil }
+                timestampMs = value.reduce(UInt64(0)) { ($0 << 8) | UInt64($1) }
+            case .signature:
+                guard value.count == signatureSize else { return nil }
+                signature = value
+            case nil:
+                break // Unknown TLV: skip for forward compatibility.
+            }
+            offset = valueEnd
+        }
+
+        guard let fingerprint, let signingKey, let timestampMs, let signature else { return nil }
+        return VouchAttestation(
+            voucheeFingerprint: fingerprint,
+            voucheeSigningKey: signingKey,
+            timestampMs: timestampMs,
+            signature: signature
+        )
+    }
+
+    // MARK: - Batch encoding
+
+    /// Encodes up to `maxBatchCount` attestations into one payload body.
+    static func encodeList(_ attestations: [VouchAttestation]) -> Data? {
+        guard !attestations.isEmpty, attestations.count <= maxBatchCount else { return nil }
+        var data = Data()
+        data.append(UInt8(attestations.count))
+        for attestation in attestations {
+            guard let encoded = attestation.encode(), encoded.count <= Int(UInt16.max) else { return nil }
+            var lengthBE = UInt16(encoded.count).bigEndian
+            withUnsafeBytes(of: &lengthBE) { data.append(contentsOf: $0) }
+            data.append(encoded)
+        }
+        return data
+    }
+
+    /// Decodes a batch payload, dropping malformed entries and ignoring
+    /// anything beyond `maxBatchCount` (sender-declared count is not trusted).
+    static func decodeList(from data: Data) -> [VouchAttestation] {
+        guard data.count > 1 else { return [] }
+        let declaredCount = Int(data[data.startIndex])
+        let limit = min(declaredCount, maxBatchCount)
+        var attestations: [VouchAttestation] = []
+        var offset = data.startIndex + 1
+        while attestations.count < limit, offset < data.endIndex {
+            guard let lengthEnd = data.index(offset, offsetBy: 2, limitedBy: data.endIndex) else { break }
+            let length = Int(data[offset]) << 8 | Int(data[offset + 1])
+            guard let entryEnd = data.index(lengthEnd, offsetBy: length, limitedBy: data.endIndex) else { break }
+            if let attestation = decode(from: Data(data[lengthEnd..<entryEnd])) {
+                attestations.append(attestation)
+            }
+            offset = entryEnd
+        }
+        return attestations
+    }
+}

bitchat/Services/BLE/BLEFragmentAssemblyBuffer.swift

@@ -64,6 +64,9 @@ struct BLEFragmentAssemblyBuffer {
         let type: UInt8
         let total: Int
         let timestamp: Date
+        let isBroadcast: Bool
+        var lastFragmentAt: Date
+        var lastResyncRequestAt: Date?
     }
 
     private var fragmentsByKey: [BLEFragmentKey: [Int: Data]] = [:]
@@ -105,7 +108,15 @@ struct BLEFragmentAssemblyBuffer {
             return .oversized(header: header, projectedSize: projectedSize, limit: limit, started: started)
         }
 
+        // Only actual progress resets the stall clock: fragment packets
+        // bypass the packet deduplicator, so relayed duplicates of an
+        // already-held index must not keep suppressing the targeted
+        // REQUEST_SYNC for a stalled stream.
+        let isNewIndex = fragmentsByKey[header.key]?[header.index] == nil
         fragmentsByKey[header.key]?[header.index] = header.fragmentData
+        if isNewIndex {
+            metadataByKey[header.key]?.lastFragmentAt = now
+        }
 
         guard let fragments = fragmentsByKey[header.key],
               fragments.count == header.total else {
@@ -138,10 +149,59 @@ struct BLEFragmentAssemblyBuffer {
         }
 
         fragmentsByKey[header.key] = [:]
-        metadataByKey[header.key] = Metadata(type: header.originalType, total: header.total, timestamp: now)
+        metadataByKey[header.key] = Metadata(
+            type: header.originalType,
+            total: header.total,
+            timestamp: now,
+            isBroadcast: header.isBroadcastFragment,
+            lastFragmentAt: now
+        )
         return true
     }
 
+    /// Fragment stream IDs (8-byte, big-endian) of incomplete broadcast
+    /// reassemblies that have not seen a new fragment for `stalledAfter`
+    /// seconds — candidates for a targeted REQUEST_SYNC. Each returned
+    /// stream is marked so it is not re-requested within `retryAfter`.
+    /// At most `RequestSyncPacket.maxFragmentIdFilterCount` streams are
+    /// returned per pass — the wire filter cannot carry more — selected
+    /// oldest-stall first; overflow streams stay unmarked and eligible for
+    /// the next pass. Directed reassemblies are excluded: peers only archive
+    /// broadcast fragments for gossip sync, so a targeted request cannot
+    /// recover them.
+    mutating func stalledBroadcastFragmentIDs(
+        stalledAfter: TimeInterval,
+        retryAfter: TimeInterval,
+        now: Date = Date()
+    ) -> [Data] {
+        var candidates: [(key: BLEFragmentKey, lastFragmentAt: Date)] = []
+        for (key, metadata) in metadataByKey {
+            guard metadata.isBroadcast,
+                  let fragments = fragmentsByKey[key],
+                  fragments.count < metadata.total,
+                  now.timeIntervalSince(metadata.lastFragmentAt) >= stalledAfter else { continue }
+            if let lastRequest = metadata.lastResyncRequestAt,
+               now.timeIntervalSince(lastRequest) < retryAfter { continue }
+            candidates.append((key: key, lastFragmentAt: metadata.lastFragmentAt))
+        }
+
+        // Mark only the streams that will actually go on the wire, so the
+        // overflow is not silently suppressed for `retryAfter`.
+        let selected = candidates
+            .sorted {
+                if $0.lastFragmentAt != $1.lastFragmentAt {
+                    return $0.lastFragmentAt < $1.lastFragmentAt
+                }
+                return ($0.key.sender, $0.key.id) < ($1.key.sender, $1.key.id)
+            }
+            .prefix(RequestSyncPacket.maxFragmentIdFilterCount)
+
+        return selected.map { candidate in
+            metadataByKey[candidate.key]?.lastResyncRequestAt = now
+            return withUnsafeBytes(of: candidate.key.id.bigEndian) { Data($0) }
+        }
+    }
+
     private static func assemblyLimit(for originalType: UInt8) -> Int {
         if originalType == MessageType.fileTransfer.rawValue {
             // Allow headroom for TLV metadata and binary framing overhead.

bitchat/Services/BLE/BLEFragmentHandler.swift

@@ -33,13 +33,21 @@ final class BLEFragmentHandler {
 
     func handle(_ packet: BitchatPacket, from peerID: PeerID) {
         let env = environment
-        // Don't process our own fragments
+        guard let header = BLEFragmentHeader(packet: packet) else { return }
+
+        // Sync replay legitimately hands us our own fragments back (the RSR
+        // ttl=0 restore path): after a relaunch the fragment store starts
+        // empty, so our sync filter doesn't cover them and peers re-offer
+        // them. Record them as seen — the next round's filter then covers
+        // them and the redelivery stops — but skip assembly: we authored
+        // the original, there is nothing to reassemble.
         if peerID == env.localPeerID() {
+            if header.isBroadcastFragment {
+                env.trackPacketSeen(packet)
+            }
             return
         }
 
-        guard let header = BLEFragmentHeader(packet: packet) else { return }
-
         if header.isBroadcastFragment {
             env.trackPacketSeen(packet)
         }

bitchat/Services/BLE/BLEOutboundPacketPolicy.swift

@@ -12,7 +12,7 @@ enum BLEOutboundPacketPolicy {
         switch MessageType(rawValue: packetType) {
         case .noiseEncrypted, .noiseHandshake:
             return true
-        case .none, .announce, .message, .leave, .requestSync, .fragment, .fileTransfer, .courierEnvelope:
+        case .none, .announce, .message, .leave, .requestSync, .fragment, .fileTransfer, .courierEnvelope, .boardPost, .ping, .pong, .nostrCarrier, .prekeyBundle, .groupMessage:
             return false
         }
     }

bitchat/Services/BLE/BLEPeerRegistry.swift

@@ -9,6 +9,7 @@ struct BLEPeerInfo: Equatable {
     var signingPublicKey: Data?
     var isVerifiedNickname: Bool
     var lastSeen: Date
+    var capabilities: PeerCapabilities = []
 }
 
 struct BLEPeerAnnounceUpdate: Equatable {
@@ -107,6 +108,15 @@ struct BLEPeerRegistry {
         peers[peerID]?.noisePublicKey?.sha256Fingerprint()
     }
 
+    func capabilities(for peerID: PeerID) -> PeerCapabilities {
+        peers[peerID.toShort()]?.capabilities ?? []
+    }
+
+    /// Peers whose last verified announce advertised the given capability.
+    func peers(advertising capability: PeerCapabilities) -> [PeerID] {
+        peers.values.filter { $0.capabilities.contains(capability) }.map(\.peerID)
+    }
+
     func displayNicknames(selfNickname: String) -> [PeerID: String] {
         let connected = peers.filter { $0.value.isConnected }
         let tuples = connected.map { ($0.key, $0.value.nickname, true) }
@@ -157,7 +167,8 @@ struct BLEPeerRegistry {
         noisePublicKey: Data,
         signingPublicKey: Data?,
         isConnected: Bool,
-        now: Date
+        now: Date,
+        capabilities: PeerCapabilities = []
     ) -> BLEPeerAnnounceUpdate {
         let existing = peers[peerID]
         let update = BLEPeerAnnounceUpdate(
@@ -173,7 +184,8 @@ struct BLEPeerRegistry {
             noisePublicKey: noisePublicKey,
             signingPublicKey: signingPublicKey,
             isVerifiedNickname: true,
-            lastSeen: now
+            lastSeen: now,
+            capabilities: capabilities
         )
 
         return update

bitchat/Services/BLE/BLEReceivePipeline.swift

@@ -51,13 +51,25 @@ struct BLEReceivePipeline {
             // Courier envelopes are directed opaque ciphertext like DMs; a
             // remote handover toward a relayed announce rides this same
             // deterministic relay treatment instead of the broadcast clamp.
+            // Ping/pong diagnostics ride it too: probes need the same
+            // deterministic multi-hop relay as DMs (always relay, jitter,
+            // no TTL cap) so RTT and hop counts reflect the real path.
+            // Directed nostrCarrier uplinks (mesh-only peer -> gateway) need
+            // the same multi-hop treatment to reach a non-adjacent gateway.
             isDirectedEncrypted: (packet.type == MessageType.noiseEncrypted.rawValue
-                || packet.type == MessageType.courierEnvelope.rawValue) && packet.recipientID != nil,
+                || packet.type == MessageType.courierEnvelope.rawValue
+                || packet.type == MessageType.ping.rawValue
+                || packet.type == MessageType.pong.rawValue
+                || packet.type == MessageType.nostrCarrier.rawValue) && packet.recipientID != nil,
             isFragment: packet.type == MessageType.fragment.rawValue,
             isDirectedFragment: packet.type == MessageType.fragment.rawValue && packet.recipientID != nil,
             isHandshake: packet.type == MessageType.noiseHandshake.rawValue,
             isAnnounce: packet.type == MessageType.announce.rawValue,
             isRequestSync: packet.type == MessageType.requestSync.rawValue,
+            // Board posts relay like broadcast messages; urgent ones get the
+            // announce-class TTL headroom so alerts travel the extra hop.
+            isUrgentBoardPost: packet.type == MessageType.boardPost.rawValue
+                && BoardWire.urgentFlag(in: packet.payload),
             degree: degree,
             highDegreeThreshold: highDegreeThreshold
         )

bitchat/Services/BLE/BLERecentPeripheralCache.swift

@@ -0,0 +1,53 @@
+import Foundation
+
+/// Remembers recently seen bitchat peripherals (fresh discoveries and dropped
+/// links) so the service can arm pending background connections against them
+/// when the app leaves the foreground. Generic over the peripheral type so
+/// the eviction/expiry logic is testable without CoreBluetooth.
+final class BLERecentPeripheralCache<Peripheral> {
+    private struct Entry {
+        let peripheral: Peripheral
+        var lastSeen: Date
+    }
+
+    private var entries: [String: Entry] = [:]
+    private let capacity: Int
+    private let maxAge: TimeInterval
+
+    init(
+        capacity: Int = TransportConfig.bleRecentPeripheralCacheCap,
+        maxAge: TimeInterval = TransportConfig.bleRecentPeripheralMaxAgeSeconds
+    ) {
+        self.capacity = capacity
+        self.maxAge = maxAge
+    }
+
+    var count: Int { entries.count }
+
+    func record(_ peripheral: Peripheral, peripheralID: String, at now: Date) {
+        entries[peripheralID] = Entry(peripheral: peripheral, lastSeen: now)
+        guard entries.count > capacity else { return }
+        // Inserts overshoot capacity by at most one; evict the stalest entry
+        if let stalest = entries.min(by: { $0.value.lastSeen < $1.value.lastSeen }) {
+            entries.removeValue(forKey: stalest.key)
+        }
+    }
+
+    /// Most-recently-seen peripherals eligible for a pending background
+    /// connect, freshest first, capped at `limit`. Expired entries are
+    /// pruned as a side effect.
+    func reconnectTargets(
+        now: Date,
+        limit: Int,
+        excluding: (String) -> Bool
+    ) -> [(peripheralID: String, peripheral: Peripheral)] {
+        let cutoff = now.addingTimeInterval(-maxAge)
+        entries = entries.filter { $0.value.lastSeen >= cutoff }
+        guard limit > 0 else { return [] }
+        return entries
+            .filter { !excluding($0.key) }
+            .sorted { $0.value.lastSeen > $1.value.lastSeen }
+            .prefix(limit)
+            .map { (peripheralID: $0.key, peripheral: $0.value.peripheral) }
+    }
+}

bitchat/Services/BLE/BLESourceRouteFailureCache.swift

@@ -0,0 +1,95 @@
+import BitFoundation
+import Foundation
+
+/// Tracks whether source-routed sends to a recipient appear to be working.
+///
+/// A routed unicast rides exactly one path, so a broken hop silently loses the
+/// packet where a flood would have healed around it. Rather than building a
+/// retransmission machine (MessageRouter already retries at a higher layer),
+/// this cache degrades: a routed send that sees no inbound traffic from the
+/// recipient within the confirmation window marks the route as failed, and
+/// subsequent sends fall back to flooding until the suppression TTL lapses.
+struct BLESourceRouteFailureCache {
+    struct Config {
+        /// How long a routed send may go unconfirmed before it counts as a
+        /// route failure.
+        var confirmationWindowSeconds: TimeInterval = TransportConfig.bleSourceRouteConfirmationWindowSeconds
+        /// How long to flood instead of routing after a failure.
+        var suppressionSeconds: TimeInterval = TransportConfig.bleSourceRouteSuppressionSeconds
+    }
+
+    private struct State {
+        var pendingSince: Date?
+        var suppressedUntil: Date?
+    }
+
+    private let config: Config
+    private var states: [PeerID: State] = [:]
+
+    init(config: Config = Config()) {
+        self.config = config
+    }
+
+    /// Whether the next directed send to `recipient` may carry a source
+    /// route. Flips the recipient into suppression when the last routed send
+    /// went unconfirmed past the confirmation window.
+    mutating func shouldAttemptRoute(to recipient: PeerID, now: Date = Date()) -> Bool {
+        guard var state = states[recipient] else { return true }
+
+        if let until = state.suppressedUntil {
+            guard now >= until else { return false }
+            state.suppressedUntil = nil
+        }
+
+        if let pending = state.pendingSince,
+           now.timeIntervalSince(pending) > config.confirmationWindowSeconds {
+            // The routed send was never confirmed: treat the route as broken
+            // and flood until the suppression window lapses.
+            state.pendingSince = nil
+            state.suppressedUntil = now.addingTimeInterval(config.suppressionSeconds)
+            states[recipient] = state
+            return false
+        }
+
+        states[recipient] = state
+        return true
+    }
+
+    /// Records that a source-routed packet was sent to `recipient`. Keeps the
+    /// earliest unconfirmed send so back-to-back packets share one deadline.
+    mutating func noteRoutedSend(to recipient: PeerID, now: Date = Date()) {
+        var state = states[recipient] ?? State()
+        if state.pendingSince == nil {
+            state.pendingSince = now
+        }
+        states[recipient] = state
+    }
+
+    /// Any inbound packet authored by `peer` confirms the pending routed send
+    /// (delivery acks and replies arrive this way). Deliberately does not
+    /// lift an active suppression: that traffic may have arrived via flood.
+    mutating func noteInboundActivity(from peer: PeerID) {
+        guard var state = states[peer] else { return }
+        state.pendingSince = nil
+        if state.suppressedUntil == nil {
+            states.removeValue(forKey: peer)
+        } else {
+            states[peer] = state
+        }
+    }
+
+    /// Drops entries that can no longer influence a routing decision. An
+    /// expired-but-unconverted pending entry is kept for as long as the
+    /// suppression it would trigger could still be active.
+    mutating func prune(now: Date = Date()) {
+        let pendingRetention = config.confirmationWindowSeconds + config.suppressionSeconds
+        states = states.filter { _, state in
+            if let until = state.suppressedUntil, now < until { return true }
+            if let pending = state.pendingSince,
+               now.timeIntervalSince(pending) <= pendingRetention {
+                return true
+            }
+            return false
+        }
+    }
+}

bitchat/Services/BLE/BLESourceRouteOriginationPolicy.swift

@@ -0,0 +1,40 @@
+import BitFoundation
+import Foundation
+
+/// Decides whether an outbound directed packet should carry a v2 source
+/// route. Pure gating logic so BLEService's hot send path stays a thin wire.
+enum BLESourceRouteOriginationPolicy {
+    /// Returns the intermediate-hop route to attach, or nil to keep the
+    /// current flood/direct-write behavior unchanged.
+    ///
+    /// Routes are only originated when every gate passes:
+    /// - we authored the packet (relays must not rewrite and re-sign someone
+    ///   else's packet; route-following for in-flight routed packets lives in
+    ///   `BLERouteForwardingPolicy`),
+    /// - the packet is directed at a single peer (not broadcast),
+    /// - the packet has TTL headroom to traverse hops (link-local TTL-0
+    ///   packets like REQUEST_SYNC never route),
+    /// - the recipient is not directly connected (a direct write already
+    ///   delivers in one hop),
+    /// - routing to the recipient is not suppressed by a recent unconfirmed
+    ///   routed send, and
+    /// - the topology yields a complete path.
+    static func route(
+        for packet: BitchatPacket,
+        to recipient: PeerID,
+        localPeerIDData: Data,
+        isRecipientConnected: (PeerID) -> Bool,
+        shouldAttemptRoute: (PeerID) -> Bool,
+        computeRoute: (PeerID) -> [Data]?
+    ) -> [Data]? {
+        guard packet.senderID == localPeerIDData else { return nil }
+        guard let recipientData = packet.recipientID,
+              recipientData.count == 8,
+              !recipientData.allSatisfy({ $0 == 0xFF }) else { return nil }
+        guard packet.ttl > 1 else { return nil }
+        guard !isRecipientConnected(recipient) else { return nil }
+        guard shouldAttemptRoute(recipient) else { return nil }
+        guard let route = computeRoute(recipient), !route.isEmpty else { return nil }
+        return route
+    }
+}

bitchat/Services/Board/BoardAlertsModel.swift

@@ -0,0 +1,160 @@
+//
+// BoardAlertsModel.swift
+// bitchat
+//
+// This is free and unencumbered software released into the public domain.
+// For more information, see <https://unlicense.org>
+//
+
+import Combine
+import Foundation
+
+/// Turns newly arriving board posts into local, scope-matched chat alerts.
+/// Everything here is derived from posts the mesh already synced — no extra
+/// wire traffic, nothing another peer can't already see.
+///
+/// - Urgent, recent pins get one system line in the matching chat (geo pin →
+///   that geohash's timeline, mesh pin → mesh chat), collapsed when several
+///   arrive together.
+/// - Every other new pin just marks the header's pin icon until the notices
+///   sheet is opened.
+@MainActor
+final class BoardAlertsModel: ObservableObject {
+    struct Dependencies {
+        /// Own posts never alert; the author already knows.
+        var isOwnPost: @MainActor (BoardPostPacket) -> Bool
+        /// Appends a local system line to a scope's chat timeline
+        /// (geohash, or "" for mesh chat).
+        var emitSystemLine: @MainActor (_ content: String, _ geohash: String) -> Void
+        var now: () -> Date = Date.init
+        /// Schedules the collapsed flush of pending urgent alerts; tests
+        /// inject a synchronous hook.
+        var scheduleFlush: (_ flush: @escaping @MainActor () -> Void) -> Void = { flush in
+            Task { @MainActor in
+                try? await Task.sleep(nanoseconds: UInt64(BoardAlertsModel.collapseDelaySeconds * 1_000_000_000))
+                flush()
+            }
+        }
+    }
+
+    /// Posts older than this at arrival are backfilled history carried in by
+    /// a peer, not something happening now; they badge but never line the chat.
+    static let inlineRecencyWindow: TimeInterval = 30 * 60
+    /// Urgent arrivals within this window collapse into one line.
+    static let collapseDelaySeconds: TimeInterval = 4
+    private static let alertContentMaxChars = 120
+
+    /// Unseen new pins by postID (hex) → geohash scope, cleared when the
+    /// notices sheet opens.
+    @Published private(set) var unseenPostScopes: [String: String] = [:]
+
+    /// PostIDs already handled this session, so store eviction/re-sync churn
+    /// can't re-alert. Bounded by session wire volume (32-byte strings).
+    private var handledPostIDs = Set<String>()
+    private var pendingUrgent: [String: [BoardPostPacket]] = [:]
+    private var flushScheduled = false
+    private let dependencies: Dependencies
+    private var cancellable: AnyCancellable?
+    private var wipeCancellable: AnyCancellable?
+
+    private enum Strings {
+        static func urgentSingle(author: String, content: String) -> String {
+            String(
+                format: String(localized: "notices.alert.urgent_single", defaultValue: "📌 urgent notice from @%@: %@", comment: "Local chat line when one urgent notice is pinned nearby"),
+                locale: .current,
+                author, content
+            )
+        }
+
+        static func urgentCollapsed(_ count: Int) -> String {
+            String(
+                format: String(localized: "notices.alert.urgent_collapsed", defaultValue: "📌 %lld new urgent notices — tap the pin to view", comment: "Local chat line when several urgent notices arrive together"),
+                locale: .current,
+                count
+            )
+        }
+    }
+
+    init(
+        arrivals: AnyPublisher<BoardPostPacket, Never>,
+        wipes: AnyPublisher<Void, Never> = Empty(completeImmediately: false).eraseToAnyPublisher(),
+        dependencies: Dependencies
+    ) {
+        self.dependencies = dependencies
+        cancellable = arrivals
+            .receive(on: DispatchQueue.main)
+            .sink { [weak self] post in
+                self?.handleArrival(post)
+            }
+        wipeCancellable = wipes
+            .receive(on: DispatchQueue.main)
+            .sink { [weak self] in
+                self?.reset()
+            }
+    }
+
+    func unseenCount(forGeohash geohash: String) -> Int {
+        unseenPostScopes.values.reduce(0) { $0 + ($1 == geohash ? 1 : 0) }
+    }
+
+    /// Marks pins in the given scopes as seen — only the scopes the notices
+    /// sheet actually shows, so unseen pins for other geohash channels keep
+    /// their badge until visited.
+    func markSeen(forScopes scopes: Set<String>) {
+        guard unseenPostScopes.contains(where: { scopes.contains($0.value) }) else { return }
+        unseenPostScopes = unseenPostScopes.filter { !scopes.contains($0.value) }
+    }
+
+    /// Panic wipe: drop everything derived from pre-wipe posts, including
+    /// urgent lines still waiting on the collapse flush.
+    func reset() {
+        pendingUrgent.removeAll()
+        handledPostIDs.removeAll()
+        guard !unseenPostScopes.isEmpty else { return }
+        unseenPostScopes.removeAll()
+    }
+
+    func handleArrival(_ post: BoardPostPacket) {
+        let postID = post.postID.hexEncodedString()
+        guard !handledPostIDs.contains(postID) else { return }
+        handledPostIDs.insert(postID)
+        guard !dependencies.isOwnPost(post) else { return }
+
+        unseenPostScopes[postID] = post.geohash
+
+        let createdAt = Date(timeIntervalSince1970: TimeInterval(post.createdAt) / 1000)
+        guard post.isUrgent,
+              dependencies.now().timeIntervalSince(createdAt) <= Self.inlineRecencyWindow else {
+            return
+        }
+        pendingUrgent[post.geohash, default: []].append(post)
+        if !flushScheduled {
+            flushScheduled = true
+            dependencies.scheduleFlush { [weak self] in
+                self?.flushPendingUrgent()
+            }
+        }
+    }
+
+    private func flushPendingUrgent() {
+        flushScheduled = false
+        let pending = pendingUrgent
+        pendingUrgent.removeAll()
+        for (geohash, posts) in pending {
+            guard let first = posts.first else { continue }
+            let line: String
+            if posts.count == 1 {
+                let author = first.authorNickname.trimmedOrNilIfEmpty ?? "anon"
+                line = Strings.urgentSingle(author: author, content: Self.truncated(first.content))
+            } else {
+                line = Strings.urgentCollapsed(posts.count)
+            }
+            dependencies.emitSystemLine(line, geohash)
+        }
+    }
+
+    private static func truncated(_ content: String) -> String {
+        guard content.count > alertContentMaxChars else { return content }
+        return content.prefix(alertContentMaxChars) + "…"
+    }
+}

bitchat/Services/Board/BoardManager.swift

@@ -0,0 +1,197 @@
+//
+// BoardManager.swift
+// bitchat
+//
+// This is free and unencumbered software released into the public domain.
+// For more information, see <https://unlicense.org>
+//
+
+import BitLogger
+import Combine
+import Foundation
+
+/// UI-facing coordinator for the bulletin board: builds and signs posts and
+/// tombstones with the device's Noise signing key, hands them to the mesh
+/// transport, and mirrors the store's live posts for SwiftUI.
+@MainActor
+final class BoardManager: ObservableObject {
+    /// Live posts across all boards, newest state from the store.
+    @Published private(set) var posts: [BoardPostPacket] = []
+
+    private let transport: Transport
+    private let store: BoardStore
+    /// Publishes a bridged kind-1 note (expiring with the board post via
+    /// NIP-40) and returns its Nostr event id, or nil when bridging failed or
+    /// was skipped.
+    private let publishToNostr: (_ content: String, _ geohash: String, _ nickname: String, _ expiresAtMs: UInt64) -> String?
+    /// Requests NIP-09 deletion of a previously bridged note.
+    private let deleteFromNostr: (_ eventID: String, _ geohash: String) -> Void
+    /// Bridged Nostr event ids by postID, for merged deletes. In-memory only:
+    /// after a relaunch a delete still tombstones the board copy, but the
+    /// Nostr copy is left to expire with relay retention.
+    private var bridgedEventIDs: [Data: String] = [:]
+    private var cancellable: AnyCancellable?
+
+    init(
+        transport: Transport,
+        store: BoardStore = .shared,
+        publishToNostr: ((String, String, String, UInt64) -> String?)? = nil,
+        deleteFromNostr: ((String, String) -> Void)? = nil
+    ) {
+        self.transport = transport
+        self.store = store
+        self.publishToNostr = publishToNostr ?? Self.livePublishToNostr
+        self.deleteFromNostr = deleteFromNostr ?? Self.liveDeleteFromNostr
+        cancellable = store.$postsSnapshot
+            .receive(on: DispatchQueue.main)
+            .sink { [weak self] snapshot in
+                self?.posts = snapshot
+            }
+    }
+
+    /// Posts for one board context, urgent first, then newest first.
+    func posts(forGeohash geohash: String) -> [BoardPostPacket] {
+        posts
+            .filter { $0.geohash == geohash }
+            .sorted {
+                if $0.isUrgent != $1.isUrgent { return $0.isUrgent }
+                return $0.createdAt > $1.createdAt
+            }
+    }
+
+    func isOwnPost(_ post: BoardPostPacket) -> Bool {
+        let key = transport.noiseSigningPublicKeyData()
+        return !key.isEmpty && key == post.authorSigningKey
+    }
+
+    /// Creates, signs, and broadcasts a board post. Returns false when the
+    /// content is empty/oversized or signing fails.
+    @discardableResult
+    func createPost(
+        content: String,
+        geohash: String,
+        urgent: Bool,
+        expiryDays: Int,
+        nickname: String
+    ) -> Bool {
+        guard let trimmed = content.trimmedOrNilIfEmpty,
+              trimmed.utf8.count <= BoardWireConstants.contentMaxBytes else {
+            return false
+        }
+        let signingKey = transport.noiseSigningPublicKeyData()
+        guard signingKey.count == BoardWireConstants.signingKeyLength else { return false }
+
+        var cleanNickname = nickname
+        while cleanNickname.utf8.count > BoardWireConstants.nicknameMaxBytes {
+            cleanNickname.removeLast()
+        }
+        let createdAt = UInt64(Date().timeIntervalSince1970 * 1000)
+        let lifetimeMs = min(
+            UInt64(max(1, expiryDays)) * 24 * 60 * 60 * 1000,
+            BoardWireConstants.maxLifetimeMs
+        )
+        let expiresAt = createdAt + lifetimeMs
+        let flags: UInt8 = urgent ? BoardPostPacket.urgentFlag : 0
+        var postID = Data(count: BoardWireConstants.postIDLength)
+        let status = postID.withUnsafeMutableBytes { buffer -> Int32 in
+            guard let base = buffer.baseAddress else { return -1 }
+            return SecRandomCopyBytes(kSecRandomDefault, buffer.count, base)
+        }
+        guard status == errSecSuccess else { return false }
+
+        let signingBytes = BoardPostPacket.signingBytes(
+            postID: postID,
+            geohash: geohash,
+            content: trimmed,
+            authorSigningKey: signingKey,
+            authorNickname: cleanNickname,
+            createdAt: createdAt,
+            expiresAt: expiresAt,
+            flags: flags
+        )
+        guard let signature = transport.noiseSignData(signingBytes) else {
+            SecureLogger.error("Board: failed to sign post", category: .session)
+            return false
+        }
+        let post = BoardPostPacket(
+            postID: postID,
+            geohash: geohash,
+            content: trimmed,
+            authorSigningKey: signingKey,
+            authorNickname: cleanNickname,
+            createdAt: createdAt,
+            expiresAt: expiresAt,
+            flags: flags,
+            signature: signature
+        )
+        transport.sendBoardPayload(BoardWire.post(post).encode())
+
+        // Nostr bridge: geohash posts also go out as kind-1 location notes so
+        // online users see them. Remember the event id for merged deletes.
+        if !geohash.isEmpty, let eventID = publishToNostr(trimmed, geohash, cleanNickname, expiresAt) {
+            bridgedEventIDs[postID] = eventID
+        }
+        return true
+    }
+
+    /// Signs and broadcasts a tombstone for one of our own posts.
+    @discardableResult
+    func deletePost(_ post: BoardPostPacket) -> Bool {
+        guard isOwnPost(post) else { return false }
+        let deletedAt = UInt64(Date().timeIntervalSince1970 * 1000)
+        let signingBytes = BoardTombstonePacket.signingBytes(postID: post.postID, deletedAt: deletedAt)
+        guard let signature = transport.noiseSignData(signingBytes) else {
+            SecureLogger.error("Board: failed to sign tombstone", category: .session)
+            return false
+        }
+        let tombstone = BoardTombstonePacket(
+            postID: post.postID,
+            authorSigningKey: post.authorSigningKey,
+            deletedAt: deletedAt,
+            signature: signature
+        )
+        transport.sendBoardPayload(BoardWire.tombstone(tombstone).encode())
+
+        // Merged delete: also retract the bridged Nostr copy when we still
+        // know its event id.
+        if !post.geohash.isEmpty, let eventID = bridgedEventIDs.removeValue(forKey: post.postID) {
+            deleteFromNostr(eventID, post.geohash)
+        }
+        return true
+    }
+
+    private static func livePublishToNostr(content: String, geohash: String, nickname: String, expiresAtMs: UInt64) -> String? {
+        let relays = GeoRelayDirectory.shared.closestRelays(toGeohash: geohash, count: TransportConfig.nostrGeoRelayCount)
+        guard !relays.isEmpty else {
+            SecureLogger.debug("Board: no geo relays for \(geohash); skipping Nostr bridge", category: .session)
+            return nil
+        }
+        do {
+            let identity = try NostrIdentityBridge().deriveIdentity(forGeohash: geohash)
+            let event = try NostrProtocol.createGeohashTextNote(
+                content: content,
+                geohash: geohash,
+                senderIdentity: identity,
+                nickname: nickname,
+                expiresAt: Date(timeIntervalSince1970: TimeInterval(expiresAtMs) / 1000)
+            )
+            NostrRelayManager.shared.sendEvent(event, to: relays)
+            return event.id
+        } catch {
+            SecureLogger.error("Board: failed to bridge post to Nostr: \(error)", category: .session)
+            return nil
+        }
+    }
+
+    private static func liveDeleteFromNostr(eventID: String, geohash: String) {
+        let relays = GeoRelayDirectory.shared.closestRelays(toGeohash: geohash, count: TransportConfig.nostrGeoRelayCount)
+        guard !relays.isEmpty else { return }
+        do {
+            let identity = try NostrIdentityBridge().deriveIdentity(forGeohash: geohash)
+            let deletion = try NostrProtocol.createDeleteEvent(ofEventID: eventID, senderIdentity: identity)
+            NostrRelayManager.shared.sendEvent(deletion, to: relays)
+        } catch {
+            SecureLogger.error("Board: failed to delete bridged Nostr note: \(error)", category: .session)
+        }
+    }
+}

bitchat/Services/Board/BoardStore.swift

@@ -0,0 +1,376 @@
+//
+// BoardStore.swift
+// bitchat
+//
+// This is free and unencumbered software released into the public domain.
+// For more information, see <https://unlicense.org>
+//
+
+import BitFoundation
+import BitLogger
+import Combine
+import Foundation
+
+/// Outcome of feeding a board packet into the store, so the transport can
+/// decide whether the packet is still worth relaying.
+enum BoardIngestResult {
+    /// New post or tombstone accepted (or a quota rejected it locally while
+    /// it remains valid for other devices).
+    case accepted
+    /// Already known; nothing changed.
+    case duplicate
+    /// Invalid, expired, or deleted; do not relay.
+    case rejected
+}
+
+/// Persistent storage for bulletin-board posts and their tombstones.
+///
+/// Posts are signed public notices designed to outlive chat: they stay on
+/// disk until their author-chosen expiry (max 7 days) and re-enter gossip
+/// sync after a restart. Tombstones are retained until the deleted post's
+/// original expiry so the delete keeps outrunning stale copies of the post.
+///
+/// The on-disk format is the raw signed packets themselves (like
+/// `GossipMessageArchive`); state is rebuilt by re-verifying and re-ingesting
+/// them on launch. Wiped on panic.
+final class BoardStore {
+    enum Limits {
+        static let maxPosts = 200
+        static let maxPostsPerAuthor = 5
+        /// Retention for a tombstone whose post we never saw: we cannot know
+        /// the original expiry, so cap at the max post lifetime.
+        static let orphanTombstoneLifetimeMs = BoardWireConstants.maxLifetimeMs
+        /// Orphan tombstones name posts nobody here has seen, so their volume
+        /// is entirely sender-controlled; cap them like posts.
+        static let maxOrphanTombstones = 100
+        static let maxOrphanTombstonesPerAuthor = 5
+        /// Allowance for clock skew between peers when judging received
+        /// timestamps against local time.
+        static let clockSkewMs: UInt64 = 60 * 60 * 1000
+    }
+
+    private struct StoredPost {
+        let post: BoardPostPacket
+        let packet: BitchatPacket
+        let rawPacket: Data
+    }
+
+    private struct StoredTombstone {
+        let tombstone: BoardTombstonePacket
+        let packet: BitchatPacket
+        let rawPacket: Data
+        let retainUntil: UInt64
+        /// True when no matching post was known at ingest time; only these
+        /// count against the orphan caps.
+        let isOrphan: Bool
+    }
+
+    /// On-disk entry: the raw signed packet, plus the retention deadline for
+    /// tombstones (derived from the deleted post's original expiry, which is
+    /// no longer recoverable once the post is gone).
+    private struct PersistedEntry: Codable {
+        let packet: Data
+        let retainUntil: UInt64?
+    }
+
+    static let shared = BoardStore()
+
+    /// Live posts, published on the main thread for the board UI.
+    @Published private(set) var postsSnapshot: [BoardPostPacket] = []
+
+    /// Fires on the main thread for each post newly accepted from the wire
+    /// (radio, sync, or local echo) — not for disk restores. Drives the
+    /// local new-pin chat alerts; duplicates never fire twice because the
+    /// store rejects them.
+    let postArrivals = PassthroughSubject<BoardPostPacket, Never>()
+
+    /// Fires on the main thread after a panic wipe so derived state (pending
+    /// alerts, unseen badges) is dropped along with the posts themselves.
+    let didWipe = PassthroughSubject<Void, Never>()
+
+    private var posts: [StoredPost] = []
+    private var tombstones: [StoredTombstone] = []
+    private let queue = DispatchQueue(label: "chat.bitchat.board.store")
+    private let fileURL: URL?
+    private let now: () -> Date
+
+    /// - Parameter fileURL: Overrides the on-disk location (tests). Ignored
+    ///   when `persistsToDisk` is false.
+    init(persistsToDisk: Bool = true, fileURL: URL? = nil, now: @escaping () -> Date = Date.init) {
+        self.now = now
+        self.fileURL = persistsToDisk ? (fileURL ?? Self.defaultFileURL()) : nil
+        loadFromDisk()
+    }
+
+    // MARK: - Ingest
+
+    /// Ingest a board packet whose payload decodes to `wire`. The caller must
+    /// have verified the wire signature already (`BoardWire.verifySignature`).
+    @discardableResult
+    func ingest(_ wire: BoardWire, packet: BitchatPacket) -> BoardIngestResult {
+        guard let rawPacket = packet.toBinaryData(padding: false) else { return .rejected }
+        let nowMs = currentMs()
+        return queue.sync {
+            let result = ingestLocked(wire, packet: packet, rawPacket: rawPacket, nowMs: nowMs)
+            if result == .accepted {
+                persistLocked()
+                if case .post(let post) = wire {
+                    DispatchQueue.main.async { [weak self] in
+                        self?.postArrivals.send(post)
+                    }
+                }
+            }
+            return result
+        }
+    }
+
+    // MARK: - Reads
+
+    /// Live posts scoped to one board (geohash, or "" for the mesh board).
+    func posts(forGeohash geohash: String) -> [BoardPostPacket] {
+        let nowMs = currentMs()
+        return queue.sync {
+            pruneExpiredLocked(nowMs: nowMs)
+            return posts.map(\.post).filter { $0.geohash == geohash }
+        }
+    }
+
+    /// Raw signed packets (posts and live tombstones) for gossip sync rounds.
+    func syncCandidates() -> [BitchatPacket] {
+        let nowMs = currentMs()
+        return queue.sync {
+            pruneExpiredLocked(nowMs: nowMs)
+            return posts.map(\.packet) + tombstones.map(\.packet)
+        }
+    }
+
+    // MARK: - Maintenance
+
+    func pruneExpired() {
+        let nowMs = currentMs()
+        queue.sync {
+            pruneExpiredLocked(nowMs: nowMs)
+            persistLocked()
+        }
+    }
+
+    /// Panic wipe: drop all board data from memory and disk.
+    func wipe() {
+        queue.sync {
+            posts.removeAll()
+            tombstones.removeAll()
+            if let fileURL {
+                try? FileManager.default.removeItem(at: fileURL)
+            }
+            publishSnapshotLocked()
+        }
+        DispatchQueue.main.async { [weak self] in
+            self?.didWipe.send()
+        }
+    }
+
+    // MARK: - Internals (call only on `queue`)
+
+    private func ingestLocked(
+        _ wire: BoardWire,
+        packet: BitchatPacket,
+        rawPacket: Data,
+        nowMs: UInt64,
+        retainUntilOverride: UInt64? = nil
+    ) -> BoardIngestResult {
+        pruneExpiredLocked(nowMs: nowMs)
+        switch wire {
+        case .post(let post):
+            return ingestPostLocked(post, packet: packet, rawPacket: rawPacket, nowMs: nowMs)
+        case .tombstone(let tombstone):
+            return ingestTombstoneLocked(tombstone, packet: packet, rawPacket: rawPacket, nowMs: nowMs, retainUntilOverride: retainUntilOverride)
+        }
+    }
+
+    private func ingestPostLocked(_ post: BoardPostPacket, packet: BitchatPacket, rawPacket: Data, nowMs: UInt64) -> BoardIngestResult {
+        guard post.expiresAt > nowMs else { return .rejected }
+        // Receive-time sanity (this is the single chokepoint for radio, sync,
+        // and disk restores): the decoder only enforces the createdAt to
+        // expiresAt span, so a forged future createdAt would sort ahead of
+        // honest posts and hold a store slot without ever pruning.
+        guard post.createdAt <= nowMs &+ Limits.clockSkewMs,
+              post.expiresAt <= nowMs &+ BoardWireConstants.maxLifetimeMs &+ Limits.clockSkewMs else {
+            return .rejected
+        }
+        if tombstones.contains(where: { $0.tombstone.postID == post.postID && $0.tombstone.authorSigningKey == post.authorSigningKey }) {
+            return .rejected
+        }
+        guard !posts.contains(where: { $0.post.postID == post.postID }) else { return .duplicate }
+
+        posts.append(StoredPost(post: post, packet: packet, rawPacket: rawPacket))
+
+        // Per-author cap, then global cap; oldest posts are evicted first.
+        let authorPosts = posts.filter { $0.post.authorSigningKey == post.authorSigningKey }
+        if authorPosts.count > Limits.maxPostsPerAuthor {
+            evictOldestLocked(from: authorPosts, keep: Limits.maxPostsPerAuthor)
+        }
+        if posts.count > Limits.maxPosts {
+            evictOldestLocked(from: posts, keep: Limits.maxPosts)
+        }
+        publishSnapshotLocked()
+        // Even when the new post itself was the eviction victim it stays
+        // valid mesh-wide; peers with room should still receive it.
+        return .accepted
+    }
+
+    private func ingestTombstoneLocked(
+        _ tombstone: BoardTombstonePacket,
+        packet: BitchatPacket,
+        rawPacket: Data,
+        nowMs: UInt64,
+        retainUntilOverride: UInt64? = nil
+    ) -> BoardIngestResult {
+        guard !tombstones.contains(where: { $0.tombstone.postID == tombstone.postID }) else { return .duplicate }
+
+        // Cap retention by both the claimed deletion time (so a doctored file
+        // cannot pin a tombstone past any legal expiry) and the receive time:
+        // deletedAt is sender-chosen, so a far-future value must not retain
+        // the tombstone longer than any post still able to arrive could live.
+        let maxRetain = min(
+            tombstone.deletedAt &+ Limits.orphanTombstoneLifetimeMs,
+            nowMs &+ Limits.orphanTombstoneLifetimeMs &+ Limits.clockSkewMs
+        )
+        let retainUntil: UInt64
+        let isOrphan: Bool
+        if let index = posts.firstIndex(where: { $0.post.postID == tombstone.postID }) {
+            let target = posts[index].post
+            // Only the author's key can delete: the tombstone signature was
+            // already verified against its embedded key, so it suffices to
+            // require that key to be the post's author key.
+            guard target.authorSigningKey == tombstone.authorSigningKey else { return .rejected }
+            retainUntil = target.expiresAt
+            isOrphan = false
+            posts.remove(at: index)
+            publishSnapshotLocked()
+        } else if let retainUntilOverride {
+            // Restored from disk: the post is long gone, so trust the
+            // retention deadline recorded when the delete was first applied.
+            // Orphans were already capped when first ingested off the air.
+            retainUntil = min(retainUntilOverride, maxRetain)
+            isOrphan = false
+        } else {
+            // Post unknown (tombstone raced ahead); keep it around so the
+            // post is suppressed if it arrives later.
+            retainUntil = maxRetain
+            isOrphan = true
+        }
+        guard retainUntil > nowMs else { return .rejected }
+        tombstones.append(StoredTombstone(tombstone: tombstone, packet: packet, rawPacket: rawPacket, retainUntil: retainUntil, isOrphan: isOrphan))
+        if isOrphan {
+            enforceOrphanTombstoneCapsLocked(author: tombstone.authorSigningKey)
+        }
+        // Like posts, a locally evicted tombstone stays valid mesh-wide.
+        return .accepted
+    }
+
+    /// Orphan tombstones reference posts we never saw, so a peer can mint
+    /// unlimited valid ones for random IDs; bound them per author and
+    /// globally, evicting the oldest received first (array order).
+    private func enforceOrphanTombstoneCapsLocked(author: Data) {
+        let authorOrphans = tombstones.filter { $0.isOrphan && $0.tombstone.authorSigningKey == author }
+        if authorOrphans.count > Limits.maxOrphanTombstonesPerAuthor {
+            removeTombstonesLocked(authorOrphans.prefix(authorOrphans.count - Limits.maxOrphanTombstonesPerAuthor))
+        }
+        let orphans = tombstones.filter(\.isOrphan)
+        if orphans.count > Limits.maxOrphanTombstones {
+            removeTombstonesLocked(orphans.prefix(orphans.count - Limits.maxOrphanTombstones))
+        }
+    }
+
+    private func removeTombstonesLocked(_ victims: ArraySlice<StoredTombstone>) {
+        guard !victims.isEmpty else { return }
+        let victimIDs = Set(victims.map { $0.tombstone.postID })
+        tombstones.removeAll { victimIDs.contains($0.tombstone.postID) }
+    }
+
+    private func evictOldestLocked(from candidates: [StoredPost], keep: Int) {
+        let victims = candidates
+            .sorted { $0.post.createdAt < $1.post.createdAt }
+            .prefix(max(0, candidates.count - keep))
+        guard !victims.isEmpty else { return }
+        let victimIDs = Set(victims.map { $0.post.postID })
+        posts.removeAll { victimIDs.contains($0.post.postID) }
+    }
+
+    private func pruneExpiredLocked(nowMs: UInt64) {
+        let postsBefore = posts.count
+        posts.removeAll { $0.post.expiresAt <= nowMs }
+        tombstones.removeAll { $0.retainUntil <= nowMs }
+        if posts.count != postsBefore {
+            publishSnapshotLocked()
+        }
+    }
+
+    private func publishSnapshotLocked() {
+        let snapshot = posts.map(\.post)
+        DispatchQueue.main.async { [weak self] in
+            self?.postsSnapshot = snapshot
+        }
+    }
+
+    private func currentMs() -> UInt64 {
+        UInt64(max(0, now().timeIntervalSince1970) * 1000)
+    }
+
+    // MARK: - Persistence
+
+    private func persistLocked() {
+        guard let fileURL else { return }
+        let payloads = posts.map { PersistedEntry(packet: $0.rawPacket, retainUntil: nil) }
+            + tombstones.map { PersistedEntry(packet: $0.rawPacket, retainUntil: $0.retainUntil) }
+        do {
+            if payloads.isEmpty {
+                try? FileManager.default.removeItem(at: fileURL)
+                return
+            }
+            try FileManager.default.createDirectory(
+                at: fileURL.deletingLastPathComponent(),
+                withIntermediateDirectories: true
+            )
+            let data = try JSONEncoder().encode(payloads)
+            var options: Data.WritingOptions = [.atomic]
+            #if os(iOS)
+            options.insert(.completeFileProtection)
+            #endif
+            try data.write(to: fileURL, options: options)
+        } catch {
+            SecureLogger.error("Failed to persist board store: \(error)", category: .session)
+        }
+    }
+
+    private func loadFromDisk() {
+        guard let fileURL,
+              let data = try? Data(contentsOf: fileURL),
+              let payloads = try? JSONDecoder().decode([PersistedEntry].self, from: data) else {
+            return
+        }
+        let nowMs = currentMs()
+        queue.sync {
+            for entry in payloads {
+                guard let packet = BitchatPacket.from(entry.packet),
+                      packet.type == MessageType.boardPost.rawValue,
+                      let wire = BoardWire.decode(from: packet.payload),
+                      wire.verifySignature() else { continue }
+                _ = ingestLocked(wire, packet: packet, rawPacket: entry.packet, nowMs: nowMs, retainUntilOverride: entry.retainUntil)
+            }
+            publishSnapshotLocked()
+        }
+    }
+
+    private static func defaultFileURL() -> URL? {
+        guard let base = try? FileManager.default.url(
+            for: .applicationSupportDirectory,
+            in: .userDomainMask,
+            appropriateFor: nil,
+            create: true
+        ) else { return nil }
+        return base
+            .appendingPathComponent("board", isDirectory: true)
+            .appendingPathComponent("posts.json")
+    }
+}

bitchat/Services/Board/UnifiedNotices.swift

@@ -0,0 +1,88 @@
+//
+// UnifiedNotices.swift
+// bitchat
+//
+// This is free and unencumbered software released into the public domain.
+// For more information, see <https://unlicense.org>
+//
+
+import Foundation
+
+/// One row in the unified notices sheet: a mesh board post or a Nostr
+/// location note, normalized for display.
+struct NoticeItem: Identifiable, Equatable {
+    enum Source: Equatable {
+        /// Signed board post carried by the mesh.
+        case board(BoardPostPacket)
+        /// Kind-1 location note seen on geo relays.
+        case nostr(LocationNotesManager.Note)
+    }
+
+    let id: String
+    let author: String
+    let content: String
+    let createdAt: Date
+    let isUrgent: Bool
+    let source: Source
+
+    var isBoardPost: Bool {
+        if case .board = source { return true }
+        return false
+    }
+
+    init(post: BoardPostPacket) {
+        id = post.postID.hexEncodedString()
+        author = post.authorNickname.trimmedOrNilIfEmpty ?? "anon"
+        content = post.content
+        createdAt = Date(timeIntervalSince1970: TimeInterval(post.createdAt) / 1000)
+        isUrgent = post.isUrgent
+        source = .board(post)
+    }
+
+    init(note: LocationNotesManager.Note) {
+        id = note.id
+        let display = note.displayName
+        author = display.split(separator: "#", maxSplits: 1, omittingEmptySubsequences: false)
+            .first.map(String.init) ?? display
+        content = note.content
+        createdAt = note.createdAt
+        isUrgent = false
+        source = .nostr(note)
+    }
+}
+
+/// Merges mesh board posts and Nostr location notes into one deduplicated
+/// list for the notices sheet's geo tab.
+enum UnifiedNotices {
+    /// Board posts on geohash channels are bridged to Nostr as kind-1 notes at
+    /// post time, so the same notice arrives twice. The copies share content
+    /// and nickname but are signed by unlinkable keys; match them
+    /// heuristically by content + author within a time window.
+    static let bridgeDedupeWindow: TimeInterval = 15 * 60
+
+    /// Returns board posts and notes as one list, urgent posts first, then
+    /// newest first. Notes that look like bridged copies of a board post are
+    /// dropped — the board copy wins because it carries urgency and supports
+    /// merged deletion. The geohash must match exactly: the notes
+    /// subscription also surfaces neighboring cells, and a same-text note
+    /// from a neighbor is not the bridged copy.
+    static func merge(posts: [BoardPostPacket], notes: [LocationNotesManager.Note]) -> [NoticeItem] {
+        var items = posts.map(NoticeItem.init(post:))
+        for note in notes {
+            let noteNickname = note.nickname?.trimmedOrNilIfEmpty ?? "anon"
+            let isBridgedCopy = posts.contains { post in
+                post.geohash == note.geohash
+                    && post.content == note.content
+                    && (post.authorNickname.trimmedOrNilIfEmpty ?? "anon") == noteNickname
+                    && abs(Date(timeIntervalSince1970: TimeInterval(post.createdAt) / 1000).timeIntervalSince(note.createdAt)) <= bridgeDedupeWindow
+            }
+            if !isBridgedCopy {
+                items.append(NoticeItem(note: note))
+            }
+        }
+        return items.sorted {
+            if $0.isUrgent != $1.isUrgent { return $0.isUrgent }
+            return $0.createdAt > $1.createdAt
+        }
+    }
+}

bitchat/Services/CashuTokenDecoder.swift

@@ -0,0 +1,339 @@
+//
+// CashuTokenDecoder.swift
+// bitchat
+//
+// Decodes Cashu ecash tokens (V3 `cashuA` = base64url JSON, V4 `cashuB` =
+// base64url CBOR) just far enough to summarize them for the UI: total
+// amount, unit, mint host, and memo. The app never contacts a mint — tokens
+// are bearer strings and redemption is delegated to an external wallet.
+//
+// This parses attacker-controlled message content, so every path is
+// bounds-checked, size-capped, and returns nil instead of trapping.
+//
+// This is free and unencumbered software released into the public domain.
+// For more information, see <https://unlicense.org>
+//
+
+import Foundation
+
+enum CashuTokenDecoder {
+
+    struct TokenInfo: Equatable {
+        /// Token serialization version: "A" (JSON) or "B" (CBOR).
+        let version: String
+        /// Sum of all proof amounts; nil when no valid amounts were found.
+        let amount: Int?
+        /// Currency unit as declared by the token (commonly "sat"), if any.
+        let unit: String?
+        /// Host of the (first) mint URL, for display.
+        let mintHost: String?
+        /// Optional sender memo, sanitized for display.
+        let memo: String?
+
+        /// "500 sat" style summary, defaulting the unit to sats per NUT-00.
+        var displayAmount: String? {
+            amount.map { "\($0) \(unit ?? "sat")" }
+        }
+    }
+
+    /// Upper bound on accepted token length in characters. Real tokens are a
+    /// few KB; anything much bigger is abuse we shouldn't spend CPU on.
+    static let maxTokenLength = 60_000
+    /// Per-proof and total amount sanity caps (order of total sats in existence).
+    private static let maxAmount: Int64 = 2_100_000_000_000_000
+
+    // MARK: - Public API
+
+    /// Extracts the bare `cashuA…`/`cashuB…` token from raw text that may be
+    /// a `cashu:`/`cashu://` URI and/or percent-encoded. Returns nil when the
+    /// input doesn't look like a Cashu token at all.
+    static func bareToken(from raw: String) -> String? {
+        var token = raw.trimmingCharacters(in: .whitespacesAndNewlines)
+        let lower = token.lowercased()
+        if lower.hasPrefix("cashu://") {
+            token = String(token.dropFirst(8))
+        } else if lower.hasPrefix("cashu:") {
+            token = String(token.dropFirst(6))
+        }
+        if token.contains("%"), let decoded = token.removingPercentEncoding {
+            token = decoded
+        }
+        guard token.count >= 12, token.count <= maxTokenLength else { return nil }
+        guard token.hasPrefix("cashuA") || token.hasPrefix("cashuB") else { return nil }
+        // Base64 / base64url payload charset ('.' appears in some legacy multi-part tokens)
+        let allowed = CharacterSet.alphanumerics.union(CharacterSet(charactersIn: "-_+/=."))
+        guard token.unicodeScalars.allSatisfy({ allowed.contains($0) }) else { return nil }
+        return token
+    }
+
+    /// Decodes a token (raw or `cashu:` URI form) into a display summary.
+    ///
+    /// In the default (permissive) mode this is for *rendering*: V3 tokens
+    /// must parse as JSON, but a V4 token whose CBOR we cannot walk still
+    /// returns a generic `TokenInfo` (version "B", no amount) because the
+    /// payload may use encodings this minimal reader doesn't support — an
+    /// unknown chip is fine for display.
+    ///
+    /// In `strict` mode (used by the `/pay` SEND path) there is no permissive
+    /// fallback: the token must cleanly decode to a known version *and* carry
+    /// a positive amount, otherwise this returns nil. This stops base64 junk
+    /// and truncated V4 tokens from being relayed as if they were valid money.
+    static func decode(_ raw: String, strict: Bool = false) -> TokenInfo? {
+        guard let token = bareToken(from: raw) else { return nil }
+        let version = String(token[token.index(token.startIndex, offsetBy: 5)])
+        guard let payload = base64URLDecode(String(token.dropFirst(6))), !payload.isEmpty else {
+            return nil
+        }
+        let info: TokenInfo?
+        switch version {
+        case "A":
+            info = decodeV3(payload)
+        case "B":
+            if let walked = decodeV4(payload) {
+                info = walked
+            } else if strict {
+                // Couldn't cleanly walk the CBOR — refuse to send it.
+                return nil
+            } else {
+                info = TokenInfo(version: "B", amount: nil, unit: nil, mintHost: nil, memo: nil)
+            }
+        default:
+            return nil
+        }
+        guard let info else { return nil }
+        if strict {
+            // A sendable token must resolve to a positive, sane amount.
+            guard let amount = info.amount, amount > 0 else { return nil }
+        }
+        return info
+    }
+
+    // MARK: - Base64url
+
+    private static func base64URLDecode(_ input: String) -> Data? {
+        var s = input
+            .replacingOccurrences(of: "-", with: "+")
+            .replacingOccurrences(of: "_", with: "/")
+        // Normalize padding (wallets emit both padded and unpadded forms)
+        s = s.replacingOccurrences(of: "=", with: "")
+        let remainder = s.count % 4
+        if remainder == 1 { return nil }
+        if remainder > 0 { s += String(repeating: "=", count: 4 - remainder) }
+        return Data(base64Encoded: s)
+    }
+
+    // MARK: - V3 (JSON)
+
+    private static func decodeV3(_ payload: Data) -> TokenInfo? {
+        guard let obj = (try? JSONSerialization.jsonObject(with: payload)) as? [String: Any],
+              let entries = obj["token"] as? [[String: Any]],
+              !entries.isEmpty else {
+            return nil
+        }
+        var total: Int64 = 0
+        var sawAmount = false
+        var mintHost: String?
+        for entry in entries {
+            if mintHost == nil, let mint = entry["mint"] as? String {
+                mintHost = sanitizedHost(from: mint)
+            }
+            for proof in (entry["proofs"] as? [[String: Any]]) ?? [] {
+                guard let number = proof["amount"] as? NSNumber else { continue }
+                let value = number.int64Value
+                guard value > 0, value <= maxAmount else { continue }
+                total += value
+                guard total <= maxAmount else { return nil }
+                sawAmount = true
+            }
+        }
+        return TokenInfo(
+            version: "A",
+            amount: sawAmount ? Int(total) : nil,
+            unit: sanitizedUnit(obj["unit"] as? String),
+            mintHost: mintHost,
+            memo: sanitizedMemo(obj["memo"] as? String)
+        )
+    }
+
+    // MARK: - V4 (CBOR)
+
+    /// Minimal walk of the NUT-00 TokenV4 CBOR map:
+    /// { "m": mint, "u": unit, "d": memo, "t": [ { "i": bytes, "p": [ { "a": amount, … } ] } ] }
+    private static func decodeV4(_ payload: Data) -> TokenInfo? {
+        var reader = CBORReader(data: payload)
+        guard case .map(let pairs)? = reader.parseValue(depth: 0) else { return nil }
+        var mintHost: String?
+        var unit: String?
+        var memo: String?
+        var total: Int64 = 0
+        var sawAmount = false
+        for (key, value) in pairs {
+            guard case .text(let name) = key else { continue }
+            switch (name, value) {
+            case ("m", .text(let mint)):
+                mintHost = sanitizedHost(from: mint)
+            case ("u", .text(let u)):
+                unit = sanitizedUnit(u)
+            case ("d", .text(let d)):
+                memo = sanitizedMemo(d)
+            case ("t", .array(let groups)):
+                for case .map(let group) in groups {
+                    for case (.text("p"), .array(let proofs)) in group {
+                        for case .map(let proof) in proofs {
+                            for case (.text("a"), .unsigned(let amount)) in proof {
+                                guard amount > 0, amount <= UInt64(maxAmount) else { continue }
+                                total += Int64(amount)
+                                guard total <= maxAmount else { return nil }
+                                sawAmount = true
+                            }
+                        }
+                    }
+                }
+            default:
+                break
+            }
+        }
+        return TokenInfo(
+            version: "B",
+            amount: sawAmount ? Int(total) : nil,
+            unit: unit,
+            mintHost: mintHost,
+            memo: memo
+        )
+    }
+
+    // MARK: - Display Sanitization (values are attacker-controlled)
+
+    private static func sanitizedHost(from mint: String) -> String? {
+        guard mint.count <= 512, let host = URL(string: mint)?.host, !host.isEmpty else { return nil }
+        return String(host.lowercased().prefix(48))
+    }
+
+    private static func sanitizedUnit(_ unit: String?) -> String? {
+        guard let unit, !unit.isEmpty, unit.count <= 12,
+              unit.unicodeScalars.allSatisfy({ CharacterSet.alphanumerics.contains($0) }) else {
+            return nil
+        }
+        return unit
+    }
+
+    private static func sanitizedMemo(_ memo: String?) -> String? {
+        guard let memo, memo.count <= 512 else { return nil }
+        let stripped = CharacterSet.controlCharacters.union(.newlines)
+        var cleaned = ""
+        cleaned.unicodeScalars.append(contentsOf: memo.unicodeScalars.filter { !stripped.contains($0) })
+        cleaned = cleaned.trimmingCharacters(in: .whitespaces)
+        guard !cleaned.isEmpty else { return nil }
+        return String(cleaned.prefix(80))
+    }
+}
+
+// MARK: - Minimal CBOR Reader
+
+/// Just enough definite-length CBOR to traverse a TokenV4 map. Bounded in
+/// depth, item count, and byte length; indefinite-length items and anything
+/// else exotic make the parse fail (the caller degrades to a generic chip).
+private struct CBORReader {
+    indirect enum Value {
+        case unsigned(UInt64)
+        case text(String)
+        case array([Value])
+        case map([(Value, Value)])
+        /// Parsed-and-skipped content we don't need (byte strings, negatives, floats…)
+        case opaque
+    }
+
+    private let bytes: [UInt8]
+    private var index = 0
+    /// Total item budget so hostile nesting can't run away.
+    private var itemBudget = 50_000
+    private static let maxDepth = 16
+    private static let maxContainerCount: UInt64 = 10_000
+
+    init(data: Data) {
+        bytes = [UInt8](data)
+    }
+
+    mutating func parseValue(depth: Int) -> Value? {
+        guard depth < Self.maxDepth, itemBudget > 0 else { return nil }
+        itemBudget -= 1
+        guard let (major, argument) = readHead() else { return nil }
+        switch major {
+        case 0: // unsigned int
+            return .unsigned(argument)
+        case 1: // negative int (argument already consumed)
+            return .opaque
+        case 2: // byte string
+            return readBytes(count: argument) != nil ? .opaque : nil
+        case 3: // text string
+            guard let raw = readBytes(count: argument) else { return nil }
+            return String(bytes: raw, encoding: .utf8).map(Value.text) ?? .opaque
+        case 4: // array
+            guard argument <= Self.maxContainerCount else { return nil }
+            var items: [Value] = []
+            items.reserveCapacity(Int(min(argument, 64)))
+            for _ in 0..<argument {
+                guard let item = parseValue(depth: depth + 1) else { return nil }
+                items.append(item)
+            }
+            return .array(items)
+        case 5: // map
+            guard argument <= Self.maxContainerCount else { return nil }
+            var pairs: [(Value, Value)] = []
+            pairs.reserveCapacity(Int(min(argument, 64)))
+            for _ in 0..<argument {
+                guard let key = parseValue(depth: depth + 1),
+                      let value = parseValue(depth: depth + 1) else { return nil }
+                pairs.append((key, value))
+            }
+            return .map(pairs)
+        case 6: // tag: skip the tag number, parse the tagged value
+            return parseValue(depth: depth + 1)
+        case 7: // simple values / floats (payload consumed by readHead)
+            return .opaque
+        default:
+            return nil
+        }
+    }
+
+    /// Reads a CBOR head byte plus its argument. Rejects indefinite lengths.
+    private mutating func readHead() -> (major: UInt8, argument: UInt64)? {
+        guard index < bytes.count else { return nil }
+        let head = bytes[index]
+        index += 1
+        let major = head >> 5
+        let info = head & 0x1F
+        switch info {
+        case 0...23:
+            return (major, UInt64(info))
+        case 24:
+            return readUInt(width: 1).map { (major, $0) }
+        case 25:
+            return readUInt(width: 2).map { (major, $0) }
+        case 26:
+            return readUInt(width: 4).map { (major, $0) }
+        case 27:
+            return readUInt(width: 8).map { (major, $0) }
+        default: // 28-30 reserved, 31 indefinite
+            return nil
+        }
+    }
+
+    private mutating func readUInt(width: Int) -> UInt64? {
+        guard bytes.count - index >= width else { return nil }
+        var value: UInt64 = 0
+        for _ in 0..<width {
+            value = (value << 8) | UInt64(bytes[index])
+            index += 1
+        }
+        return value
+    }
+
+    private mutating func readBytes(count: UInt64) -> [UInt8]? {
+        guard count <= UInt64(bytes.count - index) else { return nil }
+        let length = Int(count)
+        let slice = Array(bytes[index..<(index + length)])
+        index += length
+        return slice
+    }
+}

bitchat/Services/CommandProcessor.swift

@@ -22,6 +22,17 @@ struct CommandGeoParticipant {
     let displayName: String
 }
 
+/// The conversation a command was typed into, captured when the command is
+/// issued so deferred output (e.g. an async /ping result, which can arrive
+/// many seconds later) lands there even if the user switches chats first.
+enum CommandOutputDestination: Equatable {
+    /// The #mesh public timeline. Commands that defer output (/ping) are
+    /// mesh-only, so a non-DM origin is always the mesh timeline.
+    case meshTimeline
+    /// The private chat that was open when the command was typed.
+    case privateChat(PeerID)
+}
+
 /// Protocol defining what CommandProcessor needs from its context.
 /// This breaks the circular dependency between CommandProcessor and ChatViewModel.
 @MainActor
@@ -45,15 +56,33 @@ protocol CommandContextProvider: AnyObject {
     /// Empties the peer's chat (single-writer store intent for `/clear`).
     func clearPrivateChat(_ peerID: PeerID)
     func sendPublicRaw(_ content: String)
+    /// Sends a normal public message (with local echo) to the active channel.
+    func sendPublicMessage(_ content: String)
 
     // MARK: - System Messages
     func addLocalPrivateSystemMessage(_ content: String, to peerID: PeerID)
     func addPublicSystemMessage(_ content: String)
+    /// The conversation the user is typing into right now. Commands that
+    /// finish asynchronously capture this BEFORE starting async work, so a
+    /// chat switch cannot misroute their deferred output.
+    func currentCommandDestination() -> CommandOutputDestination
+    /// Routes deferred command output (e.g. an async /ping result) into the
+    /// conversation captured when the command was issued.
+    func addCommandOutput(_ content: String, to destination: CommandOutputDestination)
 
     // MARK: - Favorites
     /// Toggles the favorite via the unified peer flow, which persists by the
     /// real noise key and notifies the peer over mesh or Nostr.
     func toggleFavorite(peerID: PeerID)
+
+    // MARK: - Groups
+    // Group logic lives in `ChatGroupCoordinator`; these forward the parsed
+    // /group subcommands.
+    func groupCreate(named name: String) -> CommandResult
+    func groupInvite(nickname: String) -> CommandResult
+    func groupRemove(nickname: String) -> CommandResult
+    func groupLeave() -> CommandResult
+    func groupList() -> CommandResult
 }
 
 /// Processes chat commands in a focused, efficient way
@@ -100,12 +129,23 @@ final class CommandProcessor {
             return handleBlock(args)
         case "/unblock":
             return handleUnblock(args)
+        case "/group":
+            if inGeoPublic || inGeoDM { return .error(message: "groups are only for mesh peers in #mesh") }
+            return handleGroup(args)
         case "/fav":
             if inGeoPublic || inGeoDM { return .error(message: "favorites are only for mesh peers in #mesh") }
             return handleFavorite(args, add: true)
         case "/unfav":
             if inGeoPublic || inGeoDM { return .error(message: "favorites are only for mesh peers in #mesh") }
             return handleFavorite(args, add: false)
+        case "/ping":
+            if inGeoPublic || inGeoDM { return .error(message: "ping only works for mesh peers in #mesh") }
+            return handlePing(args)
+        case "/trace":
+            if inGeoPublic || inGeoDM { return .error(message: "trace only works for mesh peers in #mesh") }
+            return handleTrace(args)
+        case "/pay":
+            return handlePay(args)
         case "/help":
             return .success(message: Self.helpText)
         default:
@@ -125,6 +165,12 @@ final class CommandProcessor {
     /slap @name — slap with a large trout
     /block @name · /unblock @name
     /fav @name · /unfav @name — favorites (mesh only)
+    /group create <name> — start an encrypted group
+    /group invite @name · /group remove @name — manage members (creator)
+    /group leave · /group list — leave or list your groups
+    /ping @name — measure round-trip time (mesh only)
+    /trace @name — estimated mesh path (mesh only)
+    /pay <token> — send a cashu ecash token in this chat
     /help — this list
     """
 
@@ -331,6 +377,138 @@ final class CommandProcessor {
         return .error(message: "cannot unblock \(nickname): not found")
     }
     
+    private static let groupUsage = "usage: /group create <name> · invite @name · remove @name · leave · list"
+
+    private func handleGroup(_ args: String) -> CommandResult {
+        let parts = args.split(separator: " ", maxSplits: 1, omittingEmptySubsequences: true)
+        guard let subcommand = parts.first else {
+            return .error(message: Self.groupUsage)
+        }
+        let rest = parts.count > 1 ? String(parts[1]) : ""
+        guard let provider = contextProvider else { return .handled }
+
+        switch subcommand {
+        case "create":
+            return provider.groupCreate(named: rest)
+        case "invite":
+            return provider.groupInvite(nickname: rest)
+        case "remove":
+            return provider.groupRemove(nickname: rest)
+        case "leave":
+            return provider.groupLeave()
+        case "list":
+            return provider.groupList()
+        default:
+            return .error(message: Self.groupUsage)
+        }
+    }
+
+    // MARK: - Mesh Diagnostics
+
+    private enum MeshPeerResolution {
+        case resolved(peerID: PeerID, nickname: String)
+        case failed(CommandResult)
+    }
+
+    /// Resolves a mesh peer for /ping and /trace. Geohash identities are
+    /// rejected — diagnostics measure the BLE mesh, not Nostr.
+    private func resolveMeshPeer(_ args: String, command: String) -> MeshPeerResolution {
+        let targetName = args.trimmed
+        guard !targetName.isEmpty else {
+            return .failed(.error(message: "usage: /\(command) <nickname>"))
+        }
+        let nickname = targetName.hasPrefix("@") ? String(targetName.dropFirst()) : targetName
+        guard let peerID = contextProvider?.getPeerIDForNickname(nickname),
+              !peerID.isGeoDM, !peerID.isGeoChat else {
+            return .failed(.error(message: "cannot \(command) \(nickname): not found on mesh"))
+        }
+        return .resolved(peerID: peerID, nickname: nickname)
+    }
+
+    private func handlePing(_ args: String) -> CommandResult {
+        let target: (peerID: PeerID, nickname: String)
+        switch resolveMeshPeer(args, command: "ping") {
+        case .resolved(let peerID, let nickname): target = (peerID, nickname)
+        case .failed(let result): return result
+        }
+
+        let nickname = target.nickname
+        let currentProvider = contextProvider
+        // Capture the origin conversation now: the pong can arrive up to
+        // meshPingTimeoutSeconds later, and reading the selected chat at
+        // callback time would misroute the result after a chat switch.
+        let destination = contextProvider?.currentCommandDestination() ?? .meshTimeline
+        meshService?.sendMeshPing(to: target.peerID) { [weak currentProvider] result in
+            let provider = currentProvider
+            guard let result else {
+                provider?.addCommandOutput("no reply from \(nickname)", to: destination)
+                return
+            }
+            let hopText: String = result.hops.map { hops in
+                hops == 1 ? " · direct (1 hop)" : " · \(hops) hops"
+            } ?? ""
+            provider?.addCommandOutput("pong from \(nickname): \(result.rttMs) ms\(hopText)", to: destination)
+        }
+        return .success(message: "pinging \(nickname)…")
+    }
+
+    private func handleTrace(_ args: String) -> CommandResult {
+        let target: (peerID: PeerID, nickname: String)
+        switch resolveMeshPeer(args, command: "trace") {
+        case .resolved(let peerID, let nickname): target = (peerID, nickname)
+        case .failed(let result): return result
+        }
+
+        guard let mesh = meshService,
+              let intermediates = mesh.computeMeshPath(to: target.peerID) else {
+            return .success(message: "no known path to \(target.nickname)")
+        }
+        // Graph-derived from gossiped neighbor claims, not route-recorded —
+        // present it as an estimate.
+        let hopNames = intermediates.map { hop in
+            mesh.peerNickname(peerID: hop) ?? "\(hop.id.prefix(8))…"
+        }
+        let chain = (["you"] + hopNames + [target.nickname]).joined(separator: " → ")
+        let hops = intermediates.count + 1
+        return .success(message: "estimated path: \(chain) (\(hops) hop\(hops == 1 ? "" : "s"))")
+    }
+
+    /// `/pay <cashu-token>` — validates the token decodes, then sends it as
+    /// the message body in the current chat. Cashu tokens are bearer
+    /// instruments (whoever redeems first gets the funds), so posting one to
+    /// a public channel requires an explicit `/pay <token> public` confirm.
+    /// The app never contacts a mint; it only relays the string.
+    private func handlePay(_ args: String) -> CommandResult {
+        var parts = args.trimmed.split(separator: " ").map(String.init)
+        guard !parts.isEmpty else {
+            return .success(message: "usage: /pay <token> — paste a cashu token: /pay cashuA…")
+        }
+
+        let confirmedPublic = parts.count > 1 && parts.last?.lowercased() == "public"
+        if confirmedPublic { parts.removeLast() }
+
+        guard parts.count == 1, let token = CashuTokenDecoder.bareToken(from: parts[0]) else {
+            return .error(message: "that doesn't look like a cashu token — expected cashuA… or cashuB…")
+        }
+        guard let info = CashuTokenDecoder.decode(token, strict: true) else {
+            return .error(message: "invalid cashu token — it doesn't decode to a known token with an amount, not sending it")
+        }
+
+        let summary = info.displayAmount ?? "a cashu token"
+
+        if let peerID = contextProvider?.selectedPrivateChatPeer {
+            contextProvider?.sendPrivateMessage(token, to: peerID)
+            return .success(message: "sent \(summary) — cashu is a bearer token; whoever redeems it first gets the funds")
+        }
+
+        guard confirmedPublic else {
+            return .error(message: "this is a public channel — anyone reading it can redeem the token. send anyway: /pay <token> public")
+        }
+
+        contextProvider?.sendPublicMessage(token)
+        return .success(message: "sent \(summary) to the public channel — anyone here can redeem it")
+    }
+
     private func handleFavorite(_ args: String, add: Bool) -> CommandResult {
         let targetName = args.trimmed
         guard !targetName.isEmpty else {

bitchat/Services/Courier/CourierStore.swift

@@ -42,9 +42,11 @@ final class CourierStore {
         var sprayedTo: Set<Data>
         /// Last speculative multi-hop handover toward a relayed announce.
         var lastRemoteHandoverAt: Date?
+        /// Prekey-sealed (envelope v2) discriminator; nil for static-sealed v1.
+        let prekeyID: UInt32?
 
         var envelope: CourierEnvelope {
-            CourierEnvelope(recipientTag: recipientTag, expiry: expiry, ciphertext: ciphertext, copies: copies)
+            CourierEnvelope(recipientTag: recipientTag, expiry: expiry, ciphertext: ciphertext, copies: copies, prekeyID: prekeyID)
         }
 
         init(
@@ -56,7 +58,8 @@ final class CourierStore {
             tier: CourierDepositTier,
             copies: UInt8,
             sprayedTo: Set<Data> = [],
-            lastRemoteHandoverAt: Date? = nil
+            lastRemoteHandoverAt: Date? = nil,
+            prekeyID: UInt32? = nil
         ) {
             self.recipientTag = recipientTag
             self.expiry = expiry
@@ -67,6 +70,7 @@ final class CourierStore {
             self.copies = copies
             self.sprayedTo = sprayedTo
             self.lastRemoteHandoverAt = lastRemoteHandoverAt
+            self.prekeyID = prekeyID
         }
 
         // Files written before tiers/spray lack the newer fields; treat that
@@ -82,6 +86,7 @@ final class CourierStore {
             copies = try container.decodeIfPresent(UInt8.self, forKey: .copies) ?? 1
             sprayedTo = try container.decodeIfPresent(Set<Data>.self, forKey: .sprayedTo) ?? []
             lastRemoteHandoverAt = try container.decodeIfPresent(Date.self, forKey: .lastRemoteHandoverAt)
+            prekeyID = try container.decodeIfPresent(UInt32.self, forKey: .prekeyID)
         }
     }
 
@@ -186,7 +191,8 @@ final class CourierStore {
                 depositorNoiseKey: depositorNoiseKey,
                 storedAt: date,
                 tier: tier,
-                copies: envelope.copies
+                copies: envelope.copies,
+                prekeyID: envelope.prekeyID
             ))
             persistLocked()
             return true

bitchat/Services/Gateway/GatewayService.swift

@@ -0,0 +1,492 @@
+//
+// GatewayService.swift
+// bitchat
+//
+// This is free and unencumbered software released into the public domain.
+// For more information, see <https://unlicense.org>
+//
+
+import BitFoundation
+import BitLogger
+import Combine
+import Foundation
+
+/// Policy engine for gateway mode: an opt-in "share my internet with the
+/// mesh" bridge. While the toggle is on, this device advertises the
+/// `.gateway` capability bit, publishes signed geohash events deposited by
+/// mesh-only peers to Nostr relays (uplink), and rebroadcasts inbound relay
+/// events onto the mesh (downlink) so mesh-only peers can take part in the
+/// local geohash channel. Mesh-only peers need no toggle: their uplink
+/// engages automatically when relays are unreachable and a gateway peer
+/// exists.
+///
+/// Threat model:
+/// - Keys never leave the originating device. Mesh-only senders sign events
+///   locally with their per-geohash ephemeral identity; the gateway carries
+///   only the finished, signed event.
+/// - The gateway cannot forge or alter events: every carried event is
+///   Schnorr-verified here before it is published or rebroadcast, and again
+///   independently by relays and receivers.
+/// - Carried contents are public geohash chat, already plaintext on Nostr,
+///   so the mesh carrier adds no confidentiality loss.
+///
+/// Loop-prevention rules:
+/// 1. An event learned from a `fromGateway` mesh broadcast is never
+///    re-published to relays, never re-uplinked, and never rebroadcast
+///    (`meshBroadcastEventIDs`), so a second gateway on the same mesh cannot
+///    echo mesh-carried traffic back out. Mesh-level propagation of the
+///    original broadcast packet is the TTL relay's job, not ours.
+/// 2. An uplink deposit is published at most once (`publishedEventIDs`) and
+///    a relay event is rebroadcast at most once (`rebroadcastEventIDs`), so
+///    repeat deposits and relay echoes are absorbed. An event this gateway
+///    itself uplinked (`publishedEventIDs`) is additionally never
+///    downlink-rebroadcast: it originated on this mesh, so echoing it back
+///    when our own relay subscription redelivers it would double BLE airtime
+///    (the device-confirmed self-echo bug).
+/// 3. Uplink is only attempted for locally composed events at the send site
+///    (`GeohashSubscriptionManager.sendGeohash`); events received over the
+///    carrier never re-enter the uplink path. This is a call-site convention;
+///    the `meshBroadcastEventIDs`/`publishedEventIDs` backstops in
+///    `uplinkViaMesh` enforce it defensively and are unit-tested.
+/// Rules 1 and 2 are enforced here and unit-tested.
+/// Rebroadcast storms at the mesh layer are additionally bounded by the BLE
+/// `MessageDeduplicator` and packet TTL, and receivers dedup carried events
+/// against their own relay subscriptions via the Nostr event-ID cache in
+/// `NostrInboundPipeline`.
+///
+/// All dependencies are closure-injected (repo convention) so the policy
+/// layer is unit-testable without relays or radios.
+@MainActor
+final class GatewayService: ObservableObject {
+    enum Limits {
+        /// Uplink deposits held while relays are unreachable (CourierStore-style
+        /// bounded mailbag: bounded total, bounded per depositor).
+        static let maxQueuedUplinks = 20
+        static let maxQueuedUplinksPerDepositor = 5
+        /// Uplink deposits accepted per depositor per minute.
+        static let uplinkEventsPerMinutePerDepositor = 10
+        /// Downlink mesh rebroadcasts per minute — BLE airtime is precious.
+        /// Beyond the budget events queue (bounded, drop-oldest) and drain on
+        /// a scheduled timer once the window frees (also re-driven by the next
+        /// inbound relay event); a quiet channel does not strand its backlog.
+        static let downlinkEventsPerMinute = 30
+        static let maxPendingDownlinks = 30
+        /// Accepted clock skew for a carried ephemeral event; anything older
+        /// is stale replay the relays would drop anyway.
+        static let maxEventAgeSeconds: TimeInterval = 15 * 60
+        /// Bounded loop-prevention ID caches (oldest evicted).
+        static let maxTrackedEventIDs = 512
+    }
+
+    struct QueuedUplink {
+        let depositor: PeerID
+        let geohash: String
+        let event: NostrEvent
+        let queuedAt: Date
+    }
+
+    static let shared = GatewayService()
+
+    /// The user toggle. While true this device advertises `.gateway` and
+    /// bridges mesh <-> Nostr for geohash channels.
+    @Published private(set) var isEnabled: Bool
+
+    // MARK: Wiring (set once by the bootstrapper; fakes in tests)
+
+    /// Publishes a verified event to the geo relays for a geohash.
+    var publishToRelays: (@MainActor (NostrEvent, String) -> Void)?
+    /// Broadcasts an encoded `fromGateway` carrier payload on the mesh.
+    var broadcastToMesh: (@MainActor (Data) -> Void)?
+    /// Sends an encoded `toGateway` carrier payload directed to a gateway
+    /// peer. Returns false when the transport could not accept it.
+    var sendToGatewayPeer: (@MainActor (Data, PeerID) -> Bool)?
+    /// Reachable mesh peers currently advertising the `.gateway` capability.
+    var availableGatewayPeers: (@MainActor () -> [PeerID])?
+    /// Whether any Nostr relay connection is currently working.
+    var relaysConnected: (@MainActor () -> Bool)?
+    /// The geohash channel the local user is viewing, if any.
+    var currentGeohash: (@MainActor () -> String?)?
+    /// Injects a verified carried event into the same inbound pipeline as
+    /// relay-received events (blocking, rate limits, dedup, rendering).
+    var injectInbound: (@MainActor (NostrEvent) -> Void)?
+    /// Fired on toggle changes (advertise/withdraw the capability bit and
+    /// force a re-announce).
+    var onEnabledChanged: (@MainActor (Bool) -> Void)?
+    /// Schedules a downlink-drain closure to run after a delay. Injected so
+    /// the drain timer is deterministic in tests; nil arms a real `Task`.
+    var scheduleDrainTimer: (@MainActor (TimeInterval, @escaping @MainActor () -> Void) -> Void)?
+
+    // MARK: State
+
+    /// Loop rule 1: event IDs seen in `fromGateway` mesh broadcasts.
+    private var meshBroadcastEventIDs: BoundedIDSet
+    /// Loop rule 2 (uplink): event IDs this gateway already published.
+    private var publishedEventIDs: BoundedIDSet
+    /// Loop rule 2 (downlink): event IDs this gateway already rebroadcast.
+    private var rebroadcastEventIDs: BoundedIDSet
+
+    private(set) var queuedUplinks: [QueuedUplink] = []
+    private var uplinkDepositTimes: [PeerID: [Date]] = [:]
+    private var downlinkSendTimes: [Date] = []
+    private var pendingDownlinks: [(event: NostrEvent, geohash: String)] = []
+    /// True while a drain timer is armed, so a burst schedules at most one.
+    private var downlinkDrainScheduled = false
+
+    private let defaults: UserDefaults
+    private let now: () -> Date
+    private static let enabledKey = "gateway.userEnabled"
+
+    init(defaults: UserDefaults = .standard, now: @escaping () -> Date = Date.init) {
+        self.defaults = defaults
+        self.now = now
+        self.isEnabled = defaults.bool(forKey: Self.enabledKey)
+        self.meshBroadcastEventIDs = BoundedIDSet(capacity: Limits.maxTrackedEventIDs)
+        self.publishedEventIDs = BoundedIDSet(capacity: Limits.maxTrackedEventIDs)
+        self.rebroadcastEventIDs = BoundedIDSet(capacity: Limits.maxTrackedEventIDs)
+    }
+
+    // MARK: - Toggle
+
+    func setEnabled(_ enabled: Bool) {
+        guard enabled != isEnabled else { return }
+        isEnabled = enabled
+        defaults.set(enabled, forKey: Self.enabledKey)
+        if !enabled {
+            queuedUplinks.removeAll()
+            pendingDownlinks.removeAll()
+            uplinkDepositTimes.removeAll()
+        }
+        SecureLogger.info("🌐 Gateway mode \(enabled ? "enabled" : "disabled")", category: .session)
+        onEnabledChanged?(enabled)
+    }
+
+    // MARK: - Mesh carrier ingress (both roles)
+
+    /// Entry point for received `nostrCarrier` packets. `directedToUs` is
+    /// true for packets addressed to this device (uplink deposits); false
+    /// for broadcasts (downlink rebroadcasts from a gateway).
+    func handleMeshCarrier(_ payload: Data, from peerID: PeerID, directedToUs: Bool) {
+        guard let carrier = NostrCarrierPacket.decode(payload) else {
+            SecureLogger.debug("🌐 Gateway: dropping undecodable carrier from \(peerID.id.prefix(8))…", category: .session)
+            return
+        }
+        switch carrier.direction {
+        case .toGateway:
+            // Uplink deposits are directed; a broadcast toGateway is malformed.
+            guard directedToUs else { return }
+            handleUplinkDeposit(carrier, from: peerID)
+        case .fromGateway:
+            // Downlink rides broadcast only; a directed fromGateway is malformed.
+            guard !directedToUs else { return }
+            handleDownlinkBroadcast(carrier)
+        }
+    }
+
+    // MARK: - Uplink (gateway role: mesh peer -> internet)
+
+    private func handleUplinkDeposit(_ carrier: NostrCarrierPacket, from depositor: PeerID) {
+        guard isEnabled else { return }
+        // Cheap structural checks first (parse, size, geohash, kind, #g tag,
+        // age) — no crypto — so junk and stale replays are dropped before we
+        // ever pay for a MainActor Schnorr verify.
+        guard let event = structurallyValidEvent(from: carrier) else {
+            SecureLogger.debug("🌐 Gateway: rejected uplink deposit from \(depositor.id.prefix(8))… (failed validation)", category: .security)
+            return
+        }
+        // Dedup by the carried event ID BEFORE verification. Loop rule 1: a
+        // fromGateway-learned event is mesh-carried and must never be
+        // re-published. Loop rule 2: repeat deposits of an already handled
+        // event are absorbed. A replay of one valid deposit is short-circuited
+        // here without a per-packet signature verify.
+        guard !meshBroadcastEventIDs.contains(event.id),
+              !publishedEventIDs.contains(event.id),
+              !queuedUplinks.contains(where: { $0.event.id == event.id }) else {
+            return
+        }
+        // Consume the per-depositor rate token BEFORE the expensive verify so
+        // a flood of distinct forged/junk deposits is bounded by cheap work,
+        // not by main-actor Schnorr verifications.
+        guard allowUplinkDeposit(from: depositor) else {
+            SecureLogger.debug("🌐 Gateway: rate-limited uplink deposit from \(depositor.id.prefix(8))…", category: .session)
+            return
+        }
+        // Only now pay for cryptographic verification; receivers verify again.
+        guard event.isValidSignature() else {
+            SecureLogger.debug("🌐 Gateway: rejected uplink deposit from \(depositor.id.prefix(8))… (bad signature)", category: .security)
+            return
+        }
+
+        let accepted: Bool
+        if relaysConnected?() ?? false {
+            publish(event, geohash: carrier.geohash)
+            accepted = true
+        } else {
+            accepted = enqueueUplink(QueuedUplink(depositor: depositor, geohash: carrier.geohash, event: event, queuedAt: now()))
+        }
+
+        // Only render on our own timeline what we actually accepted for
+        // publish or queue: a quota-dropped deposit is never published and,
+        // being directed, no other peer will ever see it, so showing it would
+        // diverge our timeline permanently from what reached the channel.
+        if accepted, currentGeohash?() == carrier.geohash {
+            injectInbound?(event)
+        }
+    }
+
+    /// Publish everything queued while relays were unreachable. Called when
+    /// relay connectivity comes back.
+    func flushQueuedUplinks() {
+        guard isEnabled, relaysConnected?() ?? false, !queuedUplinks.isEmpty else { return }
+        let queued = queuedUplinks
+        queuedUplinks.removeAll()
+        for item in queued where !publishedEventIDs.contains(item.event.id) {
+            publish(item.event, geohash: item.geohash)
+        }
+    }
+
+    private func publish(_ event: NostrEvent, geohash: String) {
+        publishedEventIDs.insert(event.id)
+        publishToRelays?(event, geohash)
+        SecureLogger.info("🌐 Gateway: published carried event \(event.id.prefix(8))… to relays for #\(geohash)", category: .session)
+    }
+
+    /// Returns true when the item was actually stored for later publish.
+    @discardableResult
+    private func enqueueUplink(_ item: QueuedUplink) -> Bool {
+        let fromDepositor = queuedUplinks.filter { $0.depositor == item.depositor }.count
+        guard fromDepositor < Limits.maxQueuedUplinksPerDepositor else {
+            SecureLogger.debug("🌐 Gateway: uplink queue quota reached for \(item.depositor.id.prefix(8))…", category: .session)
+            return false
+        }
+        if queuedUplinks.count >= Limits.maxQueuedUplinks {
+            queuedUplinks.removeFirst(queuedUplinks.count - Limits.maxQueuedUplinks + 1)
+        }
+        queuedUplinks.append(item)
+        return true
+    }
+
+    private func allowUplinkDeposit(from depositor: PeerID) -> Bool {
+        let cutoff = now().addingTimeInterval(-60)
+        var times = uplinkDepositTimes[depositor, default: []]
+        times.removeAll { $0 < cutoff }
+        guard times.count < Limits.uplinkEventsPerMinutePerDepositor else {
+            uplinkDepositTimes[depositor] = times
+            return false
+        }
+        times.append(now())
+        uplinkDepositTimes[depositor] = times
+        // Bound the tracker itself against a churn of spoofed depositors.
+        if uplinkDepositTimes.count > Limits.maxTrackedEventIDs {
+            uplinkDepositTimes = uplinkDepositTimes.filter { !$0.value.isEmpty && $0.value.contains { $0 >= cutoff } }
+        }
+        return true
+    }
+
+    // MARK: - Downlink (gateway role: internet -> mesh)
+
+    /// Called for every event the gateway's own geohash-channel subscription
+    /// delivers. Wraps it in a `fromGateway` carrier and broadcasts it on
+    /// the mesh, within the airtime budget.
+    func rebroadcastRelayEvent(_ event: NostrEvent, geohash: String) {
+        guard isEnabled, broadcastToMesh != nil else { return }
+        guard event.kind == NostrProtocol.EventKind.ephemeralEvent.rawValue else { return }
+        // Freshness + geohash gate BEFORE spending any budget. A channel
+        // (re)subscribe backfills up to an hour of history (limit 200), but
+        // every receiver's `validatedEvent` drops anything older than the
+        // same window — so rebroadcasting backfill would burn the whole
+        // per-minute budget on events no mesh peer accepts. Also require the
+        // event's own `#g` tag to match the carrier geohash.
+        guard isFresh(event),
+              event.tags.contains(where: { $0.count >= 2 && $0[0] == "g" && $0[1] == geohash }) else {
+            return
+        }
+        // Loop rule 1: never rebroadcast mesh-carried events back onto the
+        // mesh. Loop rule 2 (self-echo): never rebroadcast an event this
+        // gateway itself uplinked (`publishedEventIDs`) — it originated on this
+        // very mesh, so our own relay subscription echoing it back must not
+        // double the BLE airtime by pushing it out again. Loop rule 2
+        // (downlink): rebroadcast each genuine inbound relay event at most once
+        // — but mark only AFTER it is actually sent (in `drainPendingDownlinks`),
+        // so an event dropped by the queue overflow stays retryable on relay
+        // redelivery. Guard against a redelivery re-queueing an event that is
+        // still waiting to be sent.
+        guard !meshBroadcastEventIDs.contains(event.id),
+              !publishedEventIDs.contains(event.id),
+              !rebroadcastEventIDs.contains(event.id),
+              !pendingDownlinks.contains(where: { $0.event.id == event.id }) else {
+            return
+        }
+        // Verify before spending BLE airtime; receivers verify again.
+        guard event.isValidSignature() else { return }
+
+        pendingDownlinks.append((event, geohash))
+        if pendingDownlinks.count > Limits.maxPendingDownlinks {
+            // Bandwidth guard: drop-oldest — fresher chat is worth more. The
+            // dropped event is not yet in `rebroadcastEventIDs`, so a later
+            // relay redelivery can still carry it.
+            pendingDownlinks.removeFirst(pendingDownlinks.count - Limits.maxPendingDownlinks)
+        }
+        drainPendingDownlinks()
+    }
+
+    private func drainPendingDownlinks() {
+        let cutoff = now().addingTimeInterval(-60)
+        downlinkSendTimes.removeAll { $0 < cutoff }
+        while !pendingDownlinks.isEmpty,
+              downlinkSendTimes.count < Limits.downlinkEventsPerMinute {
+            let (event, geohash) = pendingDownlinks.removeFirst()
+            // A queued event may have aged past the window while it waited;
+            // don't burn airtime on what receivers would now drop.
+            guard isFresh(event) else { continue }
+            guard let carrier = NostrCarrierPacket(direction: .fromGateway, geohash: geohash, event: event),
+                  let payload = carrier.encode() else { continue }
+            broadcastToMesh?(payload)
+            // Mark-after-send: only now is the relay event definitively
+            // rebroadcast (loop rule 2).
+            rebroadcastEventIDs.insert(event.id)
+            downlinkSendTimes.append(now())
+        }
+        // Budget exhausted with events still queued: arm a timer to drain when
+        // the window frees, instead of stranding them until the next inbound
+        // relay event (which may never come on a channel that went quiet).
+        scheduleDownlinkDrainIfNeeded()
+    }
+
+    /// Arms a single timer to drain the backlog once the per-minute window
+    /// frees. No-op when nothing is pending or a drain is already scheduled.
+    private func scheduleDownlinkDrainIfNeeded() {
+        guard !pendingDownlinks.isEmpty, !downlinkDrainScheduled else { return }
+        // The window frees when the oldest recorded send ages out of 60s.
+        let oldest = downlinkSendTimes.min() ?? now()
+        let delay = max(0.05, 60 - now().timeIntervalSince(oldest))
+        downlinkDrainScheduled = true
+        let fire: @MainActor () -> Void = { [weak self] in
+            guard let self else { return }
+            self.downlinkDrainScheduled = false
+            self.drainPendingDownlinks()
+        }
+        if let scheduleDrainTimer {
+            scheduleDrainTimer(delay, fire)
+        } else {
+            Task { @MainActor in
+                try? await Task.sleep(nanoseconds: UInt64(delay * 1_000_000_000))
+                fire()
+            }
+        }
+    }
+
+    // MARK: - Downlink (receiver role: carried event arrives over mesh)
+
+    private func handleDownlinkBroadcast(_ carrier: NostrCarrierPacket) {
+        guard let event = validatedEvent(from: carrier) else { return }
+        // Mark only AFTER signature verification, so a forged copy carrying a
+        // real event's ID cannot poison the never-republish set, and use the
+        // marking as dedup: the same broadcast relayed along several mesh
+        // paths injects once (the pipeline's Nostr event-ID cache additionally
+        // dedups against our own relay subscription).
+        guard meshBroadcastEventIDs.insert(event.id) else { return }
+        // Only inject events for the channel we're viewing; the inbound
+        // pipeline files public messages under the current geohash.
+        guard currentGeohash?() == carrier.geohash else { return }
+        injectInbound?(event)
+    }
+
+    // MARK: - Uplink (sender role: mesh-only peer with no relays)
+
+    /// Hands a locally signed event to a mesh gateway peer when we have no
+    /// working relay connection. Returns true when the event was sent.
+    ///
+    /// v1 is deliberately fire-and-forget: no gateway ack. The event also
+    /// stays in `NostrRelayManager`'s own pending queue, so if our internet
+    /// comes back the relays dedup the duplicate publish by event ID.
+    ///
+    /// Loop rule 3: call sites only pass freshly composed events (see
+    /// `GeohashSubscriptionManager.sendGeohash`); received carrier events
+    /// never reach this path, and the mesh-carried guard below backstops it.
+    func uplinkViaMesh(event: NostrEvent, geohash: String) -> Bool {
+        if relaysConnected?() ?? true { return false }
+        guard !meshBroadcastEventIDs.contains(event.id),
+              !publishedEventIDs.contains(event.id) else {
+            return false
+        }
+        // A single gateway is enough — relays fan out from there, and BLE
+        // airtime is precious.
+        guard let gateway = availableGatewayPeers?().first else { return false }
+        guard let carrier = NostrCarrierPacket(direction: .toGateway, geohash: geohash, event: event),
+              let payload = carrier.encode() else {
+            return false
+        }
+        guard sendToGatewayPeer?(payload, gateway) ?? false else { return false }
+        SecureLogger.info("🌐 Gateway: uplinked event \(event.id.prefix(8))… for #\(geohash) via mesh gateway \(gateway.id.prefix(8))…", category: .session)
+        return true
+    }
+
+    // MARK: - Validation
+
+    /// Structural and cryptographic checks every carried event must pass
+    /// before a gateway publishes it or a receiver displays it. Ordered
+    /// cheap-first; Schnorr verification runs last.
+    private func validatedEvent(from carrier: NostrCarrierPacket) -> NostrEvent? {
+        guard let event = structurallyValidEvent(from: carrier),
+              event.isValidSignature() else {
+            return nil
+        }
+        return event
+    }
+
+    /// The cheap half of `validatedEvent`: parse + size + geohash + kind +
+    /// `#g` tag + freshness, with NO signature verification. Callers that can
+    /// dedup or rate-limit on the carried ID run this first so the expensive
+    /// Schnorr verify is reached only for events that survive the cheap gates.
+    private func structurallyValidEvent(from carrier: NostrCarrierPacket) -> NostrEvent? {
+        guard carrier.eventJSON.count <= NostrCarrierPacket.maxEventJSONBytes,
+              Self.isValidGeohash(carrier.geohash),
+              let event = carrier.event(),
+              event.kind == NostrProtocol.EventKind.ephemeralEvent.rawValue,
+              event.tags.contains(where: { $0.count >= 2 && $0[0] == "g" && $0[1] == carrier.geohash }),
+              isFresh(event) else {
+            return nil
+        }
+        return event
+    }
+
+    /// True when `event.created_at` is within the accepted clock skew — the
+    /// SAME freshness window receivers enforce, so a gateway never spends
+    /// airtime on events every receiver would drop as stale.
+    private func isFresh(_ event: NostrEvent) -> Bool {
+        abs(now().timeIntervalSince1970 - TimeInterval(event.created_at)) <= Limits.maxEventAgeSeconds
+    }
+
+    static func isValidGeohash(_ geohash: String) -> Bool {
+        let allowed = Set("0123456789bcdefghjkmnpqrstuvwxyz")
+        return (1...NostrCarrierPacket.maxGeohashLength).contains(geohash.count)
+            && geohash.allSatisfy { allowed.contains($0) }
+    }
+}
+
+/// Insertion-ordered string set with a fixed capacity; the oldest entry is
+/// evicted when full.
+private struct BoundedIDSet {
+    private var members: Set<String> = []
+    private var order: [String] = []
+    let capacity: Int
+
+    init(capacity: Int) {
+        self.capacity = capacity
+    }
+
+    func contains(_ id: String) -> Bool {
+        members.contains(id)
+    }
+
+    /// Returns false when the ID was already present.
+    @discardableResult
+    mutating func insert(_ id: String) -> Bool {
+        guard members.insert(id).inserted else { return false }
+        order.append(id)
+        if order.count > capacity {
+            members.remove(order.removeFirst())
+        }
+        return true
+    }
+}

bitchat/Services/Groups/GroupProtocol.swift

@@ -0,0 +1,569 @@
+//
+// GroupProtocol.swift
+// bitchat
+//
+// Wire formats and crypto for private groups: creator-signed group state
+// (invites and key updates over Noise) and ChaCha20-Poly1305 group messages
+// broadcast as MessageType.groupMessage (0x25).
+//
+// This is free and unencumbered software released into the public domain.
+// For more information, see <https://unlicense.org>
+//
+
+import BitFoundation
+import CryptoKit
+import Foundation
+
+// MARK: - Models
+
+/// A member of a private group as pinned in the creator-signed roster.
+struct GroupMember: Codable, Equatable {
+    /// SHA-256 fingerprint (64 hex chars) of the member's Noise static key.
+    let fingerprint: String
+    /// The member's Ed25519 signing public key (32 bytes, from their announce).
+    let signingKey: Data
+    /// Nickname at invite time; display fallback when the peer is offline.
+    var nickname: String
+}
+
+/// Creator-managed encrypted group. Metadata only — the symmetric key lives
+/// in the keychain (see `GroupStore`).
+struct BitchatGroup: Codable, Equatable {
+    static let maxMembers = 16
+    static let groupIDLength = 16
+    static let keyLength = 32
+
+    /// 16 random bytes; travels in cleartext on group message packets so
+    /// relays can dedup/filter without membership.
+    let groupID: Data
+    var name: String
+    /// Bumps on every key rotation; messages are bound to the epoch they
+    /// were sealed under.
+    var epoch: UInt32
+    var members: [GroupMember]
+    /// Fingerprint of the creator — the only identity allowed to sign group
+    /// state (invites, key updates) in v1.
+    let creatorFingerprint: String
+
+    /// Virtual conversation ID this group's chat is keyed under.
+    var peerID: PeerID { PeerID(groupID: groupID) }
+
+    var creator: GroupMember? {
+        members.first { $0.fingerprint == creatorFingerprint }
+    }
+
+    func isMember(fingerprint: String) -> Bool {
+        members.contains { $0.fingerprint == fingerprint }
+    }
+
+    func member(withSigningKey signingKey: Data) -> GroupMember? {
+        members.first { $0.signingKey == signingKey }
+    }
+}
+
+// MARK: - TLV helpers
+
+enum GroupTLVError: Error, Equatable {
+    /// A TLV value exceeded the 16-bit length field. Encoding fails instead
+    /// of silently truncating (which would ship a value the receiver drops).
+    case valueTooLong
+}
+
+private enum GroupTLV {
+    /// Appends a (type, 16-bit length, value) triple. Throws rather than
+    /// truncating when `value` does not fit the 16-bit length field, so an
+    /// oversize field surfaces a send failure instead of a silently truncated
+    /// blob the recipient rejects during decrypt/verify.
+    static func put(_ type: UInt8, _ value: Data, into out: inout Data) throws {
+        guard value.count <= Int(UInt16.max) else { throw GroupTLVError.valueTooLong }
+        out.append(type)
+        let length = UInt16(value.count)
+        out.append(UInt8((length >> 8) & 0xFF))
+        out.append(UInt8(length & 0xFF))
+        out.append(value)
+    }
+
+    /// Iterates (type, value) pairs; returns nil on malformed framing.
+    static func parse(_ data: Data) -> [(type: UInt8, value: Data)]? {
+        var fields: [(UInt8, Data)] = []
+        var offset = data.startIndex
+        while offset < data.endIndex {
+            guard data.distance(from: offset, to: data.endIndex) >= 3 else { return nil }
+            let type = data[offset]
+            let high = Int(data[data.index(offset, offsetBy: 1)])
+            let low = Int(data[data.index(offset, offsetBy: 2)])
+            let length = (high << 8) | low
+            let valueStart = data.index(offset, offsetBy: 3)
+            guard data.distance(from: valueStart, to: data.endIndex) >= length else { return nil }
+            let valueEnd = data.index(valueStart, offsetBy: length)
+            fields.append((type, Data(data[valueStart..<valueEnd])))
+            offset = valueEnd
+        }
+        return fields
+    }
+
+    static func epochData(_ epoch: UInt32) -> Data {
+        var bigEndian = epoch.bigEndian
+        return withUnsafeBytes(of: &bigEndian) { Data($0) }
+    }
+
+    static func epoch(from data: Data) -> UInt32? {
+        guard data.count == 4 else { return nil }
+        return data.reduce(UInt32(0)) { ($0 << 8) | UInt32($1) }
+    }
+
+    static func timestampData(_ timestampMs: UInt64) -> Data {
+        var bigEndian = timestampMs.bigEndian
+        return withUnsafeBytes(of: &bigEndian) { Data($0) }
+    }
+
+    static func timestamp(from data: Data) -> UInt64? {
+        guard data.count == 8 else { return nil }
+        return data.reduce(UInt64(0)) { ($0 << 8) | UInt64($1) }
+    }
+}
+
+// MARK: - Roster wire form
+
+enum GroupRosterCoding {
+    private static let fingerprintLength = 32
+    private static let signingKeyLength = 32
+    private static let maxNicknameBytes = 64
+
+    /// Deterministic roster blob: count byte, then per member the raw 32-byte
+    /// fingerprint, 32-byte signing key, and length-prefixed UTF-8 nickname.
+    /// The creator signature covers the SHA-256 of these exact bytes.
+    static func encode(_ members: [GroupMember]) -> Data? {
+        guard members.count <= BitchatGroup.maxMembers else { return nil }
+        var out = Data([UInt8(members.count)])
+        for member in members {
+            guard let fingerprintData = Data(hexString: member.fingerprint),
+                  fingerprintData.count == fingerprintLength,
+                  member.signingKey.count == signingKeyLength else { return nil }
+            out.append(fingerprintData)
+            out.append(member.signingKey)
+            // Truncate on a Character boundary so the byte prefix is always
+            // valid UTF-8; a raw byte-prefix could split a multi-byte scalar
+            // and make the whole signed roster undecodable on the recipient.
+            let nickname = truncatedNicknameBytes(member.nickname)
+            out.append(UInt8(nickname.count))
+            out.append(nickname)
+        }
+        return out
+    }
+
+    static func decode(_ data: Data) -> [GroupMember]? {
+        guard let count = data.first, count <= UInt8(BitchatGroup.maxMembers) else { return nil }
+        var members: [GroupMember] = []
+        var offset = data.index(after: data.startIndex)
+        for _ in 0..<count {
+            let fixed = fingerprintLength + signingKeyLength + 1
+            guard data.distance(from: offset, to: data.endIndex) >= fixed else { return nil }
+            let fingerprintEnd = data.index(offset, offsetBy: fingerprintLength)
+            let fingerprint = Data(data[offset..<fingerprintEnd]).hexEncodedString()
+            let signingKeyEnd = data.index(fingerprintEnd, offsetBy: signingKeyLength)
+            let signingKey = Data(data[fingerprintEnd..<signingKeyEnd])
+            let nickLength = Int(data[signingKeyEnd])
+            let nickStart = data.index(after: signingKeyEnd)
+            guard data.distance(from: nickStart, to: data.endIndex) >= nickLength else { return nil }
+            let nickEnd = data.index(nickStart, offsetBy: nickLength)
+            guard let nickname = String(data: Data(data[nickStart..<nickEnd]), encoding: .utf8) else { return nil }
+            members.append(GroupMember(fingerprint: fingerprint, signingKey: signingKey, nickname: nickname))
+            offset = nickEnd
+        }
+        guard offset == data.endIndex else { return nil }
+        return members
+    }
+
+    /// UTF-8 bytes of `nickname` trimmed to at most `maxNicknameBytes`,
+    /// dropping whole Characters so the result is never split mid-scalar.
+    private static func truncatedNicknameBytes(_ nickname: String) -> Data {
+        var candidate = nickname
+        while Data(candidate.utf8).count > maxNicknameBytes {
+            candidate.removeLast()
+        }
+        return Data(candidate.utf8)
+    }
+}
+
+// MARK: - Group state payload (groupInvite / groupKeyUpdate over Noise)
+
+/// Creator-signed group state. The same wire form serves invites (0x06) and
+/// key updates (0x07); receivers verify the creator signature — computed over
+/// "bitchat-group-v1" | groupID | epoch | SHA256(key) | SHA256(roster) —
+/// against the creator's signing key pinned in the roster, and require the
+/// Noise session peer to BE the creator before accepting any state.
+struct GroupStatePayload: Equatable {
+    let groupID: Data
+    let name: String
+    /// Symmetric ChaCha20-Poly1305 group key (32 bytes) for `epoch`.
+    let key: Data
+    let epoch: UInt32
+    let members: [GroupMember]
+    let creatorFingerprint: String
+    /// Ed25519 signature by the creator.
+    let signature: Data
+
+    private enum FieldType: UInt8 {
+        case groupID = 0x01
+        case name = 0x02
+        case key = 0x03
+        case epoch = 0x04
+        case roster = 0x05
+        case creatorFingerprint = 0x06
+        case signature = 0x07
+    }
+
+    static let signingDomain = Data("bitchat-group-v1".utf8)
+
+    /// The bytes the creator signs. Binding the key, roster, and name by hash
+    /// keeps the signed content fixed-size. The name is covered so a relay
+    /// that caches/replays a signed state (e.g. store-and-forward) cannot swap
+    /// the display name while keeping a valid creator signature.
+    static func signingContent(groupID: Data, epoch: UInt32, key: Data, rosterBlob: Data, name: String) -> Data {
+        var content = signingDomain
+        content.append(groupID)
+        content.append(GroupTLV.epochData(epoch))
+        content.append(key.sha256Hash())
+        content.append(rosterBlob.sha256Hash())
+        content.append(Data(name.utf8).sha256Hash())
+        return content
+    }
+
+    /// Builds a signed state payload. Returns nil when the roster cannot be
+    /// encoded (over cap, malformed member) or signing fails.
+    static func makeSigned(
+        group: BitchatGroup,
+        key: Data,
+        sign: (Data) -> Data?
+    ) -> GroupStatePayload? {
+        guard let rosterBlob = GroupRosterCoding.encode(group.members) else { return nil }
+        let content = signingContent(groupID: group.groupID, epoch: group.epoch, key: key, rosterBlob: rosterBlob, name: group.name)
+        guard let signature = sign(content) else { return nil }
+        return GroupStatePayload(
+            groupID: group.groupID,
+            name: group.name,
+            key: key,
+            epoch: group.epoch,
+            members: group.members,
+            creatorFingerprint: group.creatorFingerprint,
+            signature: signature
+        )
+    }
+
+    func encode() -> Data? {
+        guard let rosterBlob = GroupRosterCoding.encode(members),
+              let fingerprintData = Data(hexString: creatorFingerprint),
+              fingerprintData.count == 32 else { return nil }
+        var out = Data()
+        do {
+            try GroupTLV.put(FieldType.groupID.rawValue, groupID, into: &out)
+            try GroupTLV.put(FieldType.name.rawValue, Data(name.utf8), into: &out)
+            try GroupTLV.put(FieldType.key.rawValue, key, into: &out)
+            try GroupTLV.put(FieldType.epoch.rawValue, GroupTLV.epochData(epoch), into: &out)
+            try GroupTLV.put(FieldType.roster.rawValue, rosterBlob, into: &out)
+            try GroupTLV.put(FieldType.creatorFingerprint.rawValue, fingerprintData, into: &out)
+            try GroupTLV.put(FieldType.signature.rawValue, signature, into: &out)
+        } catch {
+            return nil
+        }
+        return out
+    }
+
+    static func decode(_ data: Data) -> GroupStatePayload? {
+        guard let fields = GroupTLV.parse(data) else { return nil }
+        var groupID: Data?
+        var name: String?
+        var key: Data?
+        var epoch: UInt32?
+        var rosterBlob: Data?
+        var members: [GroupMember]?
+        var creatorFingerprint: String?
+        var signature: Data?
+
+        for (type, value) in fields {
+            switch FieldType(rawValue: type) {
+            case .groupID where value.count == BitchatGroup.groupIDLength:
+                groupID = value
+            case .name:
+                name = String(data: value, encoding: .utf8)
+            case .key where value.count == BitchatGroup.keyLength:
+                key = value
+            case .epoch:
+                epoch = GroupTLV.epoch(from: value)
+            case .roster:
+                rosterBlob = value
+                members = GroupRosterCoding.decode(value)
+            case .creatorFingerprint where value.count == 32:
+                creatorFingerprint = value.hexEncodedString()
+            case .signature where value.count == 64:
+                signature = value
+            default:
+                break // forward compatible; ignore unknown TLVs
+            }
+        }
+
+        guard let groupID, let name, let key, let epoch,
+              rosterBlob != nil, let members, !members.isEmpty,
+              let creatorFingerprint, let signature else { return nil }
+        return GroupStatePayload(
+            groupID: groupID,
+            name: name,
+            key: key,
+            epoch: epoch,
+            members: members,
+            creatorFingerprint: creatorFingerprint,
+            signature: signature
+        )
+    }
+
+    /// Verifies the creator signature against the creator's signing key
+    /// pinned in the roster, and that the creator is actually in the roster.
+    func verifyCreatorSignature() -> Bool {
+        guard members.count <= BitchatGroup.maxMembers,
+              let creator = members.first(where: { $0.fingerprint == creatorFingerprint }),
+              let rosterBlob = GroupRosterCoding.encode(members) else { return false }
+        let content = GroupStatePayload.signingContent(groupID: groupID, epoch: epoch, key: key, rosterBlob: rosterBlob, name: name)
+        return GroupCrypto.verify(signature: signature, for: content, publicKey: creator.signingKey)
+    }
+
+    var asGroup: BitchatGroup {
+        BitchatGroup(
+            groupID: groupID,
+            name: name,
+            epoch: epoch,
+            members: members,
+            creatorFingerprint: creatorFingerprint
+        )
+    }
+}
+
+// MARK: - Group message envelope (MessageType 0x25 payload)
+
+/// Cleartext framing of a group message broadcast. Only the group ID, epoch,
+/// and nonce are visible to relays; everything about the message — sender,
+/// content, timestamps — is inside the ChaCha20-Poly1305 ciphertext.
+struct GroupMessageEnvelope: Equatable {
+    let groupID: Data
+    let epoch: UInt32
+    let nonce: Data
+    /// ChaChaPoly ciphertext || 16-byte tag.
+    let ciphertext: Data
+
+    private enum FieldType: UInt8 {
+        case groupID = 0x01
+        case epoch = 0x02
+        case nonce = 0x03
+        case ciphertext = 0x04
+    }
+
+    func encode() throws -> Data {
+        var out = Data()
+        try GroupTLV.put(FieldType.groupID.rawValue, groupID, into: &out)
+        try GroupTLV.put(FieldType.epoch.rawValue, GroupTLV.epochData(epoch), into: &out)
+        try GroupTLV.put(FieldType.nonce.rawValue, nonce, into: &out)
+        try GroupTLV.put(FieldType.ciphertext.rawValue, ciphertext, into: &out)
+        return out
+    }
+
+    static func decode(_ data: Data) -> GroupMessageEnvelope? {
+        guard let fields = GroupTLV.parse(data) else { return nil }
+        var groupID: Data?
+        var epoch: UInt32?
+        var nonce: Data?
+        var ciphertext: Data?
+        for (type, value) in fields {
+            switch FieldType(rawValue: type) {
+            case .groupID where value.count == BitchatGroup.groupIDLength:
+                groupID = value
+            case .epoch:
+                epoch = GroupTLV.epoch(from: value)
+            case .nonce where value.count == 12:
+                nonce = value
+            case .ciphertext where !value.isEmpty:
+                ciphertext = value
+            default:
+                break
+            }
+        }
+        guard let groupID, let epoch, let nonce, let ciphertext else { return nil }
+        return GroupMessageEnvelope(groupID: groupID, epoch: epoch, nonce: nonce, ciphertext: ciphertext)
+    }
+}
+
+/// Decrypted, signature-verified inner content of a group message.
+struct GroupMessagePlaintext: Equatable {
+    let messageID: String
+    let senderSigningKey: Data
+    let senderNickname: String
+    let timestampMs: UInt64
+    let content: String
+}
+
+// MARK: - Crypto
+
+enum GroupCryptoError: Error, Equatable {
+    case malformedPayload
+    case signingFailed
+    case sealFailed
+    case wrongEpoch
+    case decryptionFailed
+    case badSenderSignature
+}
+
+enum GroupCrypto {
+    static let messageSigningDomain = Data("bitchat-group-msg-v1".utf8)
+
+    private enum InnerField: UInt8 {
+        case messageID = 0x01
+        case senderSigningKey = 0x02
+        case senderNickname = 0x03
+        case timestamp = 0x04
+        case content = 0x05
+        case signature = 0x06
+    }
+
+    /// Bytes the sender signs: domain | groupID | epoch | messageID | timestamp | content.
+    /// Covering the epoch stops a current member from re-sealing another
+    /// member's decrypted inner bytes under a later epoch key (the signature
+    /// would no longer verify at the new epoch).
+    static func messageSigningContent(groupID: Data, epoch: UInt32, messageID: String, timestampMs: UInt64, content: String) -> Data {
+        var data = messageSigningDomain
+        data.append(groupID)
+        data.append(GroupTLV.epochData(epoch))
+        data.append(Data(messageID.utf8))
+        data.append(GroupTLV.timestampData(timestampMs))
+        data.append(Data(content.utf8))
+        return data
+    }
+
+    static func verify(signature: Data, for data: Data, publicKey: Data) -> Bool {
+        guard let key = try? Curve25519.Signing.PublicKey(rawRepresentation: publicKey) else { return false }
+        return key.isValidSignature(signature, for: data)
+    }
+
+    /// Seals a group message: builds the signed inner TLV and encrypts it with
+    /// the epoch key. The cleartext group ID and epoch are bound into the AEAD
+    /// as additional data so ciphertext cannot be replayed across groups or
+    /// epochs. Returns the encoded 0x25 packet payload.
+    static func sealMessage(
+        content: String,
+        messageID: String,
+        senderNickname: String,
+        senderSigningKey: Data,
+        timestampMs: UInt64,
+        groupID: Data,
+        epoch: UInt32,
+        key: Data,
+        sign: (Data) -> Data?
+    ) throws -> Data {
+        let signingContent = messageSigningContent(
+            groupID: groupID,
+            epoch: epoch,
+            messageID: messageID,
+            timestampMs: timestampMs,
+            content: content
+        )
+        guard let signature = sign(signingContent), signature.count == 64 else {
+            throw GroupCryptoError.signingFailed
+        }
+
+        var inner = Data()
+        try GroupTLV.put(InnerField.messageID.rawValue, Data(messageID.utf8), into: &inner)
+        try GroupTLV.put(InnerField.senderSigningKey.rawValue, senderSigningKey, into: &inner)
+        try GroupTLV.put(InnerField.senderNickname.rawValue, Data(senderNickname.utf8), into: &inner)
+        try GroupTLV.put(InnerField.timestamp.rawValue, GroupTLV.timestampData(timestampMs), into: &inner)
+        try GroupTLV.put(InnerField.content.rawValue, Data(content.utf8), into: &inner)
+        try GroupTLV.put(InnerField.signature.rawValue, signature, into: &inner)
+
+        do {
+            let symmetricKey = SymmetricKey(data: key)
+            var aad = groupID
+            aad.append(GroupTLV.epochData(epoch))
+            let sealed = try ChaChaPoly.seal(inner, using: symmetricKey, authenticating: aad)
+            var ciphertext = sealed.ciphertext
+            ciphertext.append(sealed.tag)
+            let envelope = GroupMessageEnvelope(
+                groupID: groupID,
+                epoch: epoch,
+                nonce: Data(sealed.nonce),
+                ciphertext: ciphertext
+            )
+            return try envelope.encode()
+        } catch {
+            throw GroupCryptoError.sealFailed
+        }
+    }
+
+    /// Opens a group message envelope with the epoch key: decrypts, parses the
+    /// inner TLV, and verifies the sender's Ed25519 signature. Roster
+    /// membership of the sender is the CALLER's check — this function only
+    /// proves the payload was authored by `senderSigningKey`.
+    static func openMessage(_ envelope: GroupMessageEnvelope, key: Data) throws -> GroupMessagePlaintext {
+        let inner: Data
+        do {
+            let symmetricKey = SymmetricKey(data: key)
+            var aad = envelope.groupID
+            aad.append(GroupTLV.epochData(envelope.epoch))
+            let nonce = try ChaChaPoly.Nonce(data: envelope.nonce)
+            guard envelope.ciphertext.count > 16 else { throw GroupCryptoError.decryptionFailed }
+            let tag = envelope.ciphertext.suffix(16)
+            let body = envelope.ciphertext.prefix(envelope.ciphertext.count - 16)
+            let sealedBox = try ChaChaPoly.SealedBox(nonce: nonce, ciphertext: body, tag: tag)
+            inner = try ChaChaPoly.open(sealedBox, using: symmetricKey, authenticating: aad)
+        } catch {
+            throw GroupCryptoError.decryptionFailed
+        }
+
+        guard let fields = GroupTLV.parse(inner) else { throw GroupCryptoError.malformedPayload }
+        var messageID: String?
+        var senderSigningKey: Data?
+        var senderNickname: String?
+        var timestampMs: UInt64?
+        var content: String?
+        var signature: Data?
+        for (type, value) in fields {
+            switch InnerField(rawValue: type) {
+            case .messageID:
+                messageID = String(data: value, encoding: .utf8)
+            case .senderSigningKey where value.count == 32:
+                senderSigningKey = value
+            case .senderNickname:
+                senderNickname = String(data: value, encoding: .utf8)
+            case .timestamp:
+                timestampMs = GroupTLV.timestamp(from: value)
+            case .content:
+                content = String(data: value, encoding: .utf8)
+            case .signature where value.count == 64:
+                signature = value
+            default:
+                break
+            }
+        }
+        guard let messageID, !messageID.isEmpty,
+              let senderSigningKey,
+              let senderNickname,
+              let timestampMs,
+              let content,
+              let signature else { throw GroupCryptoError.malformedPayload }
+
+        let signingContent = messageSigningContent(
+            groupID: envelope.groupID,
+            epoch: envelope.epoch,
+            messageID: messageID,
+            timestampMs: timestampMs,
+            content: content
+        )
+        guard verify(signature: signature, for: signingContent, publicKey: senderSigningKey) else {
+            throw GroupCryptoError.badSenderSignature
+        }
+
+        return GroupMessagePlaintext(
+            messageID: messageID,
+            senderSigningKey: senderSigningKey,
+            senderNickname: senderNickname,
+            timestampMs: timestampMs,
+            content: content
+        )
+    }
+}

bitchat/Services/Groups/GroupStore.swift

@@ -0,0 +1,194 @@
+//
+// GroupStore.swift
+// bitchat
+//
+// Persistence for private groups: symmetric keys in the keychain, metadata
+// (roster, name, epoch) as protected JSON in Application Support. Both are
+// dropped by the panic wipe.
+//
+// This is free and unencumbered software released into the public domain.
+// For more information, see <https://unlicense.org>
+//
+
+import BitFoundation
+import BitLogger
+import Combine
+import Foundation
+import Security
+
+@MainActor
+final class GroupStore: ObservableObject {
+    /// All groups this device is a member of, in creation/join order.
+    @Published private(set) var groups: [BitchatGroup] = []
+
+    private let keychain: KeychainManagerProtocol
+    private let fileURL: URL?
+
+    /// - Parameter fileURL: Overrides the on-disk location (tests). Ignored
+    ///   when `persistsToDisk` is false.
+    init(keychain: KeychainManagerProtocol, persistsToDisk: Bool = true, fileURL: URL? = nil) {
+        self.keychain = keychain
+        self.fileURL = persistsToDisk ? (fileURL ?? Self.defaultFileURL()) : nil
+        loadFromDisk()
+    }
+
+    // MARK: - Reads
+
+    func group(withID groupID: Data) -> BitchatGroup? {
+        groups.first { $0.groupID == groupID }
+    }
+
+    func group(for peerID: PeerID) -> BitchatGroup? {
+        guard let groupID = peerID.groupIDData else { return nil }
+        return group(withID: groupID)
+    }
+
+    /// Current-epoch symmetric key for the group, from the keychain.
+    func key(forGroupID groupID: Data) -> Data? {
+        keychain.getIdentityKey(forKey: Self.keychainKey(for: groupID))
+    }
+
+    // MARK: - Mutations
+
+    /// Creates a new group with a random 16-byte ID and 32-byte key at
+    /// epoch 1, with the creator as sole member. Returns nil when key
+    /// generation or persistence fails.
+    func createGroup(named name: String, creator: GroupMember) -> BitchatGroup? {
+        guard let groupID = Self.randomBytes(BitchatGroup.groupIDLength),
+              let key = Self.randomBytes(BitchatGroup.keyLength) else { return nil }
+        let group = BitchatGroup(
+            groupID: groupID,
+            name: name,
+            epoch: 1,
+            members: [creator],
+            creatorFingerprint: creator.fingerprint
+        )
+        guard upsert(group, key: key) else { return nil }
+        return group
+    }
+
+    /// Inserts or replaces a group and its current key. Rejects rosters over
+    /// the hard cap or groups whose creator is missing from the roster.
+    @discardableResult
+    func upsert(_ group: BitchatGroup, key: Data) -> Bool {
+        guard group.groupID.count == BitchatGroup.groupIDLength,
+              key.count == BitchatGroup.keyLength,
+              !group.members.isEmpty,
+              group.members.count <= BitchatGroup.maxMembers,
+              group.creator != nil else { return false }
+        guard keychain.saveIdentityKey(key, forKey: Self.keychainKey(for: group.groupID)) else {
+            SecureLogger.error("Failed to store group key in keychain", category: .security)
+            return false
+        }
+        if let index = groups.firstIndex(where: { $0.groupID == group.groupID }) {
+            groups[index] = group
+        } else {
+            groups.append(group)
+        }
+        persist()
+        return true
+    }
+
+    /// Updates the roster of an existing group without changing key or epoch
+    /// (creator-side invite). Enforces the member cap.
+    @discardableResult
+    func updateRoster(groupID: Data, members: [GroupMember]) -> BitchatGroup? {
+        guard let index = groups.firstIndex(where: { $0.groupID == groupID }),
+              !members.isEmpty,
+              members.count <= BitchatGroup.maxMembers,
+              members.contains(where: { $0.fingerprint == groups[index].creatorFingerprint }) else { return nil }
+        groups[index].members = members
+        persist()
+        return groups[index]
+    }
+
+    /// Rotates the group key (creator-side removal/rotation): new random key,
+    /// epoch + 1, and the given roster. Returns the updated group and new key.
+    func rotateKey(groupID: Data, members: [GroupMember]) -> (group: BitchatGroup, key: Data)? {
+        guard let existing = group(withID: groupID),
+              let newKey = Self.randomBytes(BitchatGroup.keyLength) else { return nil }
+        var rotated = existing
+        rotated.epoch = existing.epoch &+ 1
+        rotated.members = members
+        guard upsert(rotated, key: newKey) else { return nil }
+        return (rotated, newKey)
+    }
+
+    func removeGroup(withID groupID: Data) {
+        groups.removeAll { $0.groupID == groupID }
+        _ = keychain.deleteIdentityKey(forKey: Self.keychainKey(for: groupID))
+        persist()
+    }
+
+    /// Panic wipe: drop all group keys and metadata from memory and disk.
+    /// (The panic flow also nukes the whole keychain; deleting per-group keys
+    /// here keeps the store safe to wipe on its own.)
+    func wipe() {
+        for group in groups {
+            _ = keychain.deleteIdentityKey(forKey: Self.keychainKey(for: group.groupID))
+        }
+        groups.removeAll()
+        if let fileURL {
+            try? FileManager.default.removeItem(at: fileURL)
+        }
+    }
+
+    // MARK: - Internals
+
+    private static func keychainKey(for groupID: Data) -> String {
+        "groupKey-\(groupID.hexEncodedString())"
+    }
+
+    private static func randomBytes(_ count: Int) -> Data? {
+        var bytes = Data(count: count)
+        let status = bytes.withUnsafeMutableBytes { buffer -> OSStatus in
+            guard let baseAddress = buffer.baseAddress else { return errSecParam }
+            return SecRandomCopyBytes(kSecRandomDefault, count, baseAddress)
+        }
+        return status == errSecSuccess ? bytes : nil
+    }
+
+    private func persist() {
+        guard let fileURL else { return }
+        do {
+            if groups.isEmpty {
+                try? FileManager.default.removeItem(at: fileURL)
+                return
+            }
+            try FileManager.default.createDirectory(
+                at: fileURL.deletingLastPathComponent(),
+                withIntermediateDirectories: true
+            )
+            let data = try JSONEncoder().encode(groups)
+            var options: Data.WritingOptions = [.atomic]
+            #if os(iOS)
+            options.insert(.completeFileProtection)
+            #endif
+            try data.write(to: fileURL, options: options)
+        } catch {
+            SecureLogger.error("Failed to persist group store: \(error)", category: .session)
+        }
+    }
+
+    private func loadFromDisk() {
+        guard let fileURL,
+              let data = try? Data(contentsOf: fileURL),
+              let stored = try? JSONDecoder().decode([BitchatGroup].self, from: data) else {
+            return
+        }
+        // Only groups whose key survived in the keychain are usable.
+        groups = stored.filter { key(forGroupID: $0.groupID) != nil }
+    }
+
+    private static func defaultFileURL() -> URL? {
+        guard let base = try? FileManager.default.url(
+            for: .applicationSupportDirectory,
+            in: .userDomainMask,
+            appropriateFor: nil,
+            create: true
+        ) else { return nil }
+        return base
+            .appendingPathComponent("groups", isDirectory: true)
+            .appendingPathComponent("groups.json")
+    }
+}

bitchat/Services/KeychainManager.swift

@@ -15,7 +15,50 @@ final class KeychainManager: KeychainManagerProtocol {
     // Use consistent service name for all keychain items
     private let service = BitchatApp.bundleID
     private let appGroup = "group.\(BitchatApp.bundleID)"
-    
+
+    // AfterFirstUnlock, not WhenUnlocked: the mesh keeps running with the
+    // device locked (identity-cache saves failed with -25308 throughout
+    // locked-phone testing), and a wake-on-proximity relaunch via BLE state
+    // restoration must be able to read the noise keys before the user
+    // unlocks. Backup/sync semantics are unchanged (not ThisDeviceOnly).
+    private static let itemAccessibility = kSecAttrAccessibleAfterFirstUnlock
+
+    init() {
+        #if os(iOS)
+        migrateAccessibilityIfNeeded()
+        #endif
+    }
+
+    #if os(iOS)
+    /// One-time upgrade of items created under WhenUnlocked. New saves get
+    /// the right class on their own (saves are delete-then-add), but the
+    /// long-lived identity keys are written once and would otherwise stay
+    /// unreadable while the device is locked.
+    private func migrateAccessibilityIfNeeded() {
+        let flag = "keychain.accessibility.afterFirstUnlock.migrated"
+        guard !UserDefaults.standard.bool(forKey: flag) else { return }
+
+        let query: [String: Any] = [
+            kSecClass as String: kSecClassGenericPassword,
+            kSecAttrService as String: service
+        ]
+        let update: [String: Any] = [
+            kSecAttrAccessible as String: Self.itemAccessibility
+        ]
+        let status = SecItemUpdate(query as CFDictionary, update as CFDictionary)
+        switch status {
+        case errSecSuccess, errSecItemNotFound:
+            // Nothing to migrate on a fresh install; both are terminal.
+            UserDefaults.standard.set(true, forKey: flag)
+            SecureLogger.info("Keychain accessibility migrated to AfterFirstUnlock (status \(status))", category: .keychain)
+        default:
+            // Likely errSecInteractionNotAllowed (relaunched while locked) —
+            // leave the flag unset so the next launch retries.
+            SecureLogger.warning("Keychain accessibility migration deferred (status \(status))", category: .keychain)
+        }
+    }
+    #endif
+
     // MARK: - Identity Keys
     
     func saveIdentityKey(_ keyData: Data, forKey key: String) -> Bool {
@@ -62,7 +105,7 @@ final class KeychainManager: KeychainManagerProtocol {
             kSecAttrAccount as String: key,
             kSecValueData as String: data,
             kSecAttrService as String: service,
-            kSecAttrAccessible as String: kSecAttrAccessibleWhenUnlocked,
+            kSecAttrAccessible as String: Self.itemAccessibility,
             kSecAttrLabel as String: "bitchat-\(key)"
         ]
         #if os(macOS)
@@ -227,7 +270,7 @@ final class KeychainManager: KeychainManagerProtocol {
             kSecAttrAccount as String: key,
             kSecValueData as String: data,
             kSecAttrService as String: service,
-            kSecAttrAccessible as String: kSecAttrAccessibleWhenUnlocked,
+            kSecAttrAccessible as String: Self.itemAccessibility,
             kSecAttrLabel as String: "bitchat-\(key)"
         ]
         #if os(macOS)

bitchat/Services/LocationNotesManager.swift

@@ -67,6 +67,9 @@ final class LocationNotesManager: ObservableObject {
         let content: String
         let createdAt: Date
         let nickname: String?
+        /// The matched `g` tag: the cell the note was posted to, which can be
+        /// a neighbor of the subscribed geohash.
+        let geohash: String
 
         var displayName: String {
             let suffix = String(pubkey.suffix(4))
@@ -82,6 +85,8 @@ final class LocationNotesManager: ObservableObject {
     @Published private(set) var initialLoadComplete: Bool = false
     @Published private(set) var state: State = .loading
     @Published private(set) var errorMessage: String?
+    /// Public key of our per-geohash Nostr identity; identifies our own notes.
+    private var ownPubkey: String?
     private var subscriptionID: String?
     private var noteIDs = Set<String>() // O(1) duplicate detection
     private var directoryUpdateCancellable: AnyCancellable?
@@ -104,10 +109,10 @@ final class LocationNotesManager: ObservableObject {
         let norm = geohash.lowercased()
         self.geohash = norm
         self.dependencies = dependencies
-        // Validate geohash (building-level precision: 8 chars)
-        if !Geohash.isValidBuildingGeohash(norm) {
-            SecureLogger.warning("LocationNotesManager: invalid geohash '\(norm)' (expected 8 valid base32 chars)", category: .session)
+        if !Geohash.isValidGeohash(norm) {
+            SecureLogger.warning("LocationNotesManager: invalid geohash '\(norm)' (expected 1-12 valid base32 chars)", category: .session)
         }
+        ownPubkey = (try? dependencies.deriveIdentity(norm))?.publicKeyHex
         subscribe()
         // The relay directory may load after init (remote fetch over Tor);
         // retry automatically instead of staying stuck on "no relays".
@@ -123,9 +128,8 @@ final class LocationNotesManager: ObservableObject {
     func setGeohash(_ newGeohash: String) {
         let norm = newGeohash.lowercased()
         guard norm != geohash else { return }
-        // Validate geohash (building-level precision: 8 chars)
-        guard Geohash.isValidBuildingGeohash(norm) else {
-            SecureLogger.warning("LocationNotesManager: rejecting invalid geohash '\(norm)' (expected 8 valid base32 chars)", category: .session)
+        guard Geohash.isValidGeohash(norm) else {
+            SecureLogger.warning("LocationNotesManager: rejecting invalid geohash '\(norm)' (expected 1-12 valid base32 chars)", category: .session)
             return
         }
         if let sub = subscriptionID {
@@ -137,6 +141,7 @@ final class LocationNotesManager: ObservableObject {
         initialLoadComplete = false
         errorMessage = nil
         geohash = norm
+        ownPubkey = (try? dependencies.deriveIdentity(norm))?.publicKeyHex
         notes.removeAll()
         noteIDs.removeAll()
         subscribe()
@@ -193,14 +198,14 @@ final class LocationNotesManager: ObservableObject {
             guard let self = self else { return }
             guard event.kind == NostrProtocol.EventKind.textNote.rawValue else { return }
             // Ensure matching tag - accept any of our 9 geohashes
-            guard event.tags.contains(where: { tag in
+            guard let matchedGeohash = event.tags.first(where: { tag in
                 tag.count >= 2 && tag[0].lowercased() == "g" && validGeohashes.contains(tag[1].lowercased())
-            }) else { return }
+            })?[1].lowercased() else { return }
             guard !self.noteIDs.contains(event.id) else { return }
             self.noteIDs.insert(event.id)
             let nick = event.tags.first(where: { $0.first?.lowercased() == "n" && $0.count >= 2 })?.dropFirst().first
             let ts = Date(timeIntervalSince1970: TimeInterval(event.created_at))
-            let note = Note(id: event.id, pubkey: event.pubkey, content: event.content, createdAt: ts, nickname: nick)
+            let note = Note(id: event.id, pubkey: event.pubkey, content: event.content, createdAt: ts, nickname: nick, geohash: matchedGeohash)
             self.notes.append(note)
             self.notes.sort { $0.createdAt > $1.createdAt }
             self.enforceMemoryCap()
@@ -239,7 +244,8 @@ final class LocationNotesManager: ObservableObject {
                 pubkey: id.publicKeyHex,
                 content: trimmed,
                 createdAt: Date(timeIntervalSince1970: TimeInterval(event.created_at)),
-                nickname: nickname
+                nickname: nickname,
+                geohash: geohash
             )
             self.noteIDs.insert(event.id)
             self.notes.insert(echo, at: 0)
@@ -252,6 +258,36 @@ final class LocationNotesManager: ObservableObject {
         }
     }
 
+    /// Whether the note was published by this device's identity for the
+    /// current geohash (and can therefore be deleted with NIP-09).
+    func isOwnNote(_ note: Note) -> Bool {
+        guard let ownPubkey else { return false }
+        return note.pubkey == ownPubkey
+    }
+
+    /// Requests NIP-09 deletion of one of our own notes and removes it locally.
+    @discardableResult
+    func delete(note: Note) -> Bool {
+        guard isOwnNote(note) else { return false }
+        let relays = dependencies.relayLookup(geohash, TransportConfig.nostrGeoRelayCount)
+        guard !relays.isEmpty else {
+            state = .noRelays
+            errorMessage = Strings.noRelays
+            return false
+        }
+        do {
+            let identity = try dependencies.deriveIdentity(geohash)
+            let deletion = try NostrProtocol.createDeleteEvent(ofEventID: note.id, senderIdentity: identity)
+            dependencies.sendEvent(deletion, relays)
+            // Keep the id in noteIDs so a relay replay can't resurrect it.
+            notes.removeAll { $0.id == note.id }
+            return true
+        } catch {
+            SecureLogger.error("LocationNotesManager: failed to delete note: \(error)", category: .session)
+            return false
+        }
+    }
+
     /// Enforces defensive memory cap on notes array (keeps newest).
     private func enforceMemoryCap() {
         if notes.count > maxNotesInMemory {

bitchat/Services/MeshTopologyTracker.swift

@@ -10,6 +10,10 @@ final class MeshTopologyTracker {
     private var claims: [RoutingID: Set<RoutingID>] = [:]
     // Last time we received an update from a node
     private var lastSeen: [RoutingID: Date] = [:]
+    // Highest protocol version observed from each node's decoded packets.
+    // Nodes absent from this map are assumed v1-only and are never used as
+    // hops (or targets) for version-gated routes.
+    private var observedVersions: [RoutingID: (version: UInt8, seenAt: Date)] = [:]
 
     // Maximum age for topology claims to be considered fresh for routing
     // Routes computed using stale topology can fail when the network has changed
@@ -19,48 +23,75 @@ final class MeshTopologyTracker {
         queue.sync(flags: .barrier) {
             self.claims.removeAll()
             self.lastSeen.removeAll()
+            self.observedVersions.removeAll()
         }
     }
 
     /// Update the topology with a node's self-reported neighbor list
-    func updateNeighbors(for sourceData: Data?, neighbors: [Data]) {
+    func updateNeighbors(for sourceData: Data?, neighbors: [Data], at now: Date = Date()) {
         guard let source = sanitize(sourceData) else { return }
         // Sanitize neighbors and exclude self-loops
         let validNeighbors = Set(neighbors.compactMap { sanitize($0) }).subtracting([source])
-        
+
         queue.sync(flags: .barrier) {
             self.claims[source] = validNeighbors
-            self.lastSeen[source] = Date()
+            self.lastSeen[source] = now
         }
     }
 
+    /// Record the protocol version observed on a decoded packet from a node.
+    /// Only versions above the v1 baseline are stored; the highest wins.
+    func recordObservedVersion(_ version: UInt8, for peerData: Data?, at now: Date = Date()) {
+        guard version > 1, let peer = sanitize(peerData) else { return }
+        queue.sync(flags: .barrier) {
+            let current = self.observedVersions[peer]?.version ?? 1
+            self.observedVersions[peer] = (version: max(version, current), seenAt: now)
+        }
+    }
+
+    /// Raw directed neighbor claims, for diagnostics (topology map, /trace).
+    /// Callers treat the claims as advisory: announces cap `directNeighbors`
+    /// at 10, so an edge may be claimed by only one of its endpoints.
+    func adjacencySnapshot() -> [Data: Set<Data>] {
+        queue.sync { claims }
+    }
+
     func removePeer(_ data: Data?) {
         guard let peer = sanitize(data) else { return }
         queue.sync(flags: .barrier) {
             self.claims.removeValue(forKey: peer)
             self.lastSeen.removeValue(forKey: peer)
+            self.observedVersions.removeValue(forKey: peer)
         }
     }
-    
+
     /// Prune nodes that haven't updated their topology in `age` seconds
-    func prune(olderThan age: TimeInterval) {
-        let deadline = Date().addingTimeInterval(-age)
+    func prune(olderThan age: TimeInterval, now: Date = Date()) {
+        let deadline = now.addingTimeInterval(-age)
         queue.sync(flags: .barrier) {
             let stale = self.lastSeen.filter { $0.value < deadline }
             for (peer, _) in stale {
                 self.claims.removeValue(forKey: peer)
                 self.lastSeen.removeValue(forKey: peer)
             }
+            self.observedVersions = self.observedVersions.filter { $0.value.seenAt >= deadline }
         }
     }
 
-    func computeRoute(from start: Data?, to goal: Data?, maxHops: Int = 10) -> [Data]? {
+    /// BFS over confirmed, fresh edges. When `requiringVersion` is set, every
+    /// node on the path except the source (i.e. all intermediate hops and the
+    /// target) must have been observed speaking at least that protocol
+    /// version — a v1-only hop cannot decode a v2 routed packet.
+    func computeRoute(from start: Data?, to goal: Data?, maxHops: Int = 10, requiringVersion: UInt8? = nil, now: Date = Date()) -> [Data]? {
         guard let source = sanitize(start), let target = sanitize(goal) else { return nil }
         if source == target { return [] } // Direct connection, no intermediate hops
 
         return queue.sync {
-            let now = Date()
             let freshnessDeadline = now.addingTimeInterval(-Self.routeFreshnessThreshold)
+            func meetsRequiredVersion(_ peer: RoutingID) -> Bool {
+                guard let requiringVersion else { return true }
+                return (observedVersions[peer]?.version ?? 1) >= requiringVersion
+            }
 
             // BFS
             var visited: Set<RoutingID> = [source]
@@ -86,6 +117,10 @@ final class MeshTopologyTracker {
                 for neighbor in neighbors {
                     if visited.contains(neighbor) { continue }
 
+                    // Version gate: skip nodes not known to speak the
+                    // required protocol version.
+                    guard meetsRequiredVersion(neighbor) else { continue }
+
                     // CONFIRMED EDGE CHECK:
                     // 'last' claims 'neighbor' (checked above)
                     // Does 'neighbor' claim 'last'?

bitchat/Services/MessageDeduplicationService.swift

@@ -172,17 +172,37 @@ final class MessageDeduplicationService {
     /// Cache for Nostr ACK deduplication (messageId:ackType:senderPubkey format)
     private let nostrAckCache: LRUDeduplicationCache<Bool>
 
+    /// Optional cross-launch persistence for the Nostr event cache. NIP-59
+    /// randomizes gift-wrap timestamps, so DM subscriptions look back 24h and
+    /// relays redeliver the same events on every launch; without this record
+    /// each relaunch reprocesses old PMs and acks. Nil (tests, macOS callers
+    /// that don't opt in) keeps the cache purely in-memory.
+    private let nostrEventStore: NostrProcessedEventStore?
+    private let nostrEventCapacity: Int
+    private var persistScheduled = false
+    private var pendingPersistIDs: [String] = []
+
     /// Creates a new deduplication service with specified capacities.
     /// - Parameters:
     ///   - contentCapacity: Max entries for content cache
     ///   - nostrEventCapacity: Max entries for Nostr event cache
+    ///   - nostrEventStore: Optional disk store preloading and persisting
+    ///     processed Nostr event IDs across launches
     init(
         contentCapacity: Int = TransportConfig.contentLRUCap,
-        nostrEventCapacity: Int = TransportConfig.uiProcessedNostrEventsCap
+        nostrEventCapacity: Int = TransportConfig.uiProcessedNostrEventsCap,
+        nostrEventStore: NostrProcessedEventStore? = nil
     ) {
         self.contentCache = LRUDeduplicationCache(capacity: contentCapacity)
         self.nostrEventCache = LRUDeduplicationCache(capacity: nostrEventCapacity)
         self.nostrAckCache = LRUDeduplicationCache(capacity: nostrEventCapacity)
+        self.nostrEventStore = nostrEventStore
+        self.nostrEventCapacity = nostrEventCapacity
+        if let nostrEventStore {
+            for eventID in nostrEventStore.load() {
+                nostrEventCache.record(eventID, value: true)
+            }
+        }
     }
 
     // MARK: - Content Deduplication
@@ -239,6 +259,26 @@ final class MessageDeduplicationService {
     /// - Parameter eventId: The event ID
     func recordNostrEvent(_ eventId: String) {
         nostrEventCache.record(eventId, value: true)
+        if nostrEventStore != nil {
+            pendingPersistIDs.append(eventId)
+            schedulePersistIfNeeded()
+        }
+    }
+
+    /// Debounced persistence: bursts of inbound events (reconnect redelivery)
+    /// collapse into one append. Append-merge rather than snapshot, so a
+    /// transient in-memory clear between flushes can't shrink the disk record.
+    private func schedulePersistIfNeeded() {
+        guard let nostrEventStore, !persistScheduled else { return }
+        persistScheduled = true
+        Task { @MainActor [weak self] in
+            try? await Task.sleep(nanoseconds: 2_000_000_000)
+            guard let self else { return }
+            self.persistScheduled = false
+            let newIDs = self.pendingPersistIDs
+            self.pendingPersistIDs.removeAll()
+            nostrEventStore.append(newIDs, cap: self.nostrEventCapacity)
+        }
     }
 
     // MARK: - Nostr ACK Deduplication
@@ -263,14 +303,20 @@ final class MessageDeduplicationService {
 
     // MARK: - Clear
 
-    /// Clears all caches
+    /// Clears all caches. This is the wipe/panic path: the persisted
+    /// gift-wrap record goes with everything else.
     func clearAll() {
         contentCache.clear()
         nostrEventCache.clear()
         nostrAckCache.clear()
+        pendingPersistIDs.removeAll()
+        nostrEventStore?.wipe()
     }
 
-    /// Clears only the Nostr caches (events and ACKs)
+    /// Clears only the in-memory Nostr caches (events and ACKs). Runs on
+    /// every geohash channel switch, so the disk record deliberately
+    /// survives — wiping it here would forfeit cross-launch gift-wrap dedup
+    /// each time the user changes channels (flagged by Codex on #1398).
     func clearNostrCaches() {
         nostrEventCache.clear()
         nostrAckCache.clear()

bitchat/Services/NetworkActivationService.swift

@@ -25,14 +25,20 @@ extension NostrRelayManager: NetworkActivationRelayControlling {}
 extension TorURLSession: NetworkActivationProxyControlling {}
 
 /// Coordinates when the app is allowed to start Tor and connect to Nostr relays.
-/// Policy: permit start when either location permissions are authorized OR
-/// there exists at least one mutual favorite. Otherwise, do not start.
+/// Policy: permit start when (location permissions are authorized OR there
+/// exists at least one mutual favorite) AND the device has a usable network
+/// path. When there is provably no network at all we do not bootstrap Tor or
+/// spin relay reconnects — that only wastes battery on a mesh-only/offline
+/// device. BLE mesh is entirely independent of this gate.
 @MainActor
 final class NetworkActivationService: ObservableObject {
     static let shared = NetworkActivationService()
 
     @Published private(set) var activationAllowed: Bool = false
     @Published private(set) var userTorEnabled: Bool = true
+    /// Coarse, debounced network reachability. `false` only when the OS reports
+    /// no usable interface at all. Surfaced for UI ("offline" vs "connecting").
+    @Published private(set) var isNetworkReachable: Bool = true
 
     private var cancellables = Set<AnyCancellable>()
     private var started = false
@@ -43,6 +49,7 @@ final class NetworkActivationService: ObservableObject {
     private let mutualFavoritesPublisher: AnyPublisher<Set<Data>, Never>
     private let permissionProvider: () -> LocationChannelManager.PermissionState
     private let mutualFavoritesProvider: () -> Set<Data>
+    private let reachabilityMonitor: NetworkReachabilityMonitoring
     private let torController: NetworkActivationTorControlling
     // Resolved lazily: NostrRelayManager.init() reads NetworkActivationService.shared
     // (via its live dependencies), so capturing NostrRelayManager.shared here would
@@ -58,6 +65,7 @@ final class NetworkActivationService: ObservableObject {
         mutualFavoritesPublisher = FavoritesPersistenceService.shared.$mutualFavorites.eraseToAnyPublisher()
         permissionProvider = { LocationChannelManager.shared.permissionState }
         mutualFavoritesProvider = { FavoritesPersistenceService.shared.mutualFavorites }
+        reachabilityMonitor = NWPathReachabilityMonitor()
         torController = TorManager.shared
         relayControllerProvider = { NostrRelayManager.shared }
         proxyController = TorURLSession.shared
@@ -70,6 +78,7 @@ final class NetworkActivationService: ObservableObject {
         mutualFavoritesPublisher: AnyPublisher<Set<Data>, Never>,
         permissionProvider: @escaping () -> LocationChannelManager.PermissionState,
         mutualFavoritesProvider: @escaping () -> Set<Data>,
+        reachabilityMonitor: NetworkReachabilityMonitoring,
         torController: NetworkActivationTorControlling,
         relayController: NetworkActivationRelayControlling,
         proxyController: NetworkActivationProxyControlling,
@@ -80,6 +89,7 @@ final class NetworkActivationService: ObservableObject {
         self.mutualFavoritesPublisher = mutualFavoritesPublisher
         self.permissionProvider = permissionProvider
         self.mutualFavoritesProvider = mutualFavoritesProvider
+        self.reachabilityMonitor = reachabilityMonitor
         self.torController = torController
         self.relayControllerProvider = { relayController }
         self.proxyController = proxyController
@@ -96,8 +106,12 @@ final class NetworkActivationService: ObservableObject {
             userTorEnabled = true
         }
 
+        // Begin (idempotent) reachability monitoring and seed initial state.
+        reachabilityMonitor.start()
+        isNetworkReachable = reachabilityMonitor.isReachable
+
         // Initial compute
-        let allowed = basePolicyAllowed()
+        let allowed = effectiveAllowed()
         activationAllowed = allowed
         torAutoStartDesired = allowed && userTorEnabled
         torController.setAutoStartAllowed(torAutoStartDesired)
@@ -123,6 +137,21 @@ final class NetworkActivationService: ObservableObject {
                 self?.reevaluate()
             }
             .store(in: &cancellables)
+
+        // React to network reachability changes (debounced, unsatisfied-only).
+        reachabilityMonitor.reachabilityPublisher
+            .receive(on: DispatchQueue.main)
+            .sink { [weak self] reachable in
+                guard let self else { return }
+                guard reachable != self.isNetworkReachable else { return }
+                self.isNetworkReachable = reachable
+                SecureLogger.info(
+                    "NetworkActivationService: isNetworkReachable -> \(reachable)",
+                    category: .session
+                )
+                self.reevaluate()
+            }
+            .store(in: &cancellables)
     }
 
     func setUserTorEnabled(_ enabled: Bool) {
@@ -138,7 +167,7 @@ final class NetworkActivationService: ObservableObject {
     }
 
     private func reevaluate() {
-        let allowed = basePolicyAllowed()
+        let allowed = effectiveAllowed()
         let torDesired = allowed && userTorEnabled
         let statusChanged = allowed != activationAllowed
         let torChanged = torDesired != torAutoStartDesired
@@ -163,12 +192,20 @@ final class NetworkActivationService: ObservableObject {
         }
     }
 
+    /// Base policy: who is allowed to use the network at all (permission or a
+    /// mutual favorite), ignoring current link state.
     private func basePolicyAllowed() -> Bool {
         let permOK = permissionProvider() == .authorized
         let hasMutual = !mutualFavoritesProvider().isEmpty
         return permOK || hasMutual
     }
 
+    /// Effective gate: base policy AND a usable network path. When there is
+    /// provably no network, Tor bootstrap and relay reconnects are suppressed.
+    private func effectiveAllowed() -> Bool {
+        basePolicyAllowed() && reachabilityMonitor.isReachable
+    }
+
     private func applyTorState(torDesired: Bool) {
         proxyController.setProxyMode(useTor: torDesired)
         if torDesired {

bitchat/Services/NetworkReachabilityMonitor.swift

@@ -0,0 +1,179 @@
+import Foundation
+import Combine
+import BitLogger
+#if canImport(Network)
+import Network
+#endif
+
+/// Coarse, conservative network-reachability signal used to gate Tor bootstrap
+/// and Nostr relay connections.
+///
+/// Policy (deliberately conservative):
+/// - Reports `false` only when the OS says there is *no* usable interface at
+///   all (`NWPath.Status.unsatisfied`). A flaky-but-present link stays
+///   `true` because Tor tolerates intermittent connectivity, and tearing down
+///   on the first hiccup would cost more battery/latency than it saves.
+/// - Transitions are debounced (see `ReachabilityDebounce`) so path flapping
+///   does not thrash Tor/relay startup.
+/// - Starts optimistic (`true`) so nothing is ever suppressed before the first
+///   path evaluation arrives.
+///
+/// BLE mesh must never consult this monitor — the mesh works fully offline.
+@MainActor
+protocol NetworkReachabilityMonitoring: AnyObject {
+    /// Current debounced coarse reachability.
+    var isReachable: Bool { get }
+    /// Emits the debounced reachability whenever it changes (main-actor).
+    var reachabilityPublisher: AnyPublisher<Bool, Never> { get }
+    /// Begin monitoring. Idempotent.
+    func start()
+}
+
+/// Pure debounce/decision logic for reachability, split out so it can be
+/// unit-tested without the Network framework or real timers.
+///
+/// A candidate state only becomes the committed state once it has been stable
+/// (uninterrupted) for `interval`. Any observation matching the committed state
+/// cancels a pending opposite change, which is what makes flapping a no-op.
+struct ReachabilityDebounce {
+    let interval: TimeInterval
+    private(set) var committed: Bool
+    private var pending: (value: Bool, since: Date)?
+
+    init(interval: TimeInterval, initial: Bool) {
+        self.interval = interval
+        self.committed = initial
+    }
+
+    /// Whether a change is currently waiting out the debounce window.
+    var hasPendingChange: Bool { pending != nil }
+
+    /// Time left before the pending change may commit, or `nil` when nothing
+    /// is pending. Lets callers schedule a flush at the true deadline instead
+    /// of a full interval from "now" (duplicate observations must not push
+    /// the deadline out).
+    func pendingRemaining(at now: Date) -> TimeInterval? {
+        guard let pending else { return nil }
+        return max(0, interval - now.timeIntervalSince(pending.since))
+    }
+
+    /// Feed a raw observation. Returns the new committed value if it changed,
+    /// otherwise `nil`.
+    mutating func observe(reachable: Bool, at now: Date) -> Bool? {
+        if reachable == committed {
+            // Already in this state — cancel any pending opposite change.
+            pending = nil
+            return nil
+        }
+        // Differs from committed: (re)arm the pending change, preserving the
+        // timestamp if we're already waiting on this same target value.
+        if pending?.value != reachable {
+            pending = (reachable, now)
+        }
+        return commitIfAged(at: now)
+    }
+
+    /// Called from a timer to commit a pending change once it has aged past
+    /// `interval`. Returns the new committed value if it changed, else `nil`.
+    mutating func flush(at now: Date) -> Bool? {
+        commitIfAged(at: now)
+    }
+
+    private mutating func commitIfAged(at now: Date) -> Bool? {
+        guard let pending else { return nil }
+        guard now.timeIntervalSince(pending.since) >= interval else { return nil }
+        committed = pending.value
+        self.pending = nil
+        return committed
+    }
+}
+
+/// Always-reachable stub. Used as the default in tests and as the fallback on
+/// platforms without the Network framework, so reachability never suppresses
+/// startup by itself.
+@MainActor
+final class AlwaysReachableMonitor: NetworkReachabilityMonitoring {
+    var isReachable: Bool { true }
+    var reachabilityPublisher: AnyPublisher<Bool, Never> {
+        Empty(completeImmediately: false).eraseToAnyPublisher()
+    }
+    func start() {}
+}
+
+/// `NWPathMonitor`-backed reachability. All state lives on the main actor; the
+/// background path callback hops here before touching the debounce.
+@MainActor
+final class NWPathReachabilityMonitor: NetworkReachabilityMonitoring {
+    private let subject: CurrentValueSubject<Bool, Never>
+    private var debounce: ReachabilityDebounce
+    private var flushWorkItem: DispatchWorkItem?
+    private var started = false
+    private let now: () -> Date
+
+    #if canImport(Network)
+    private var monitor: NWPathMonitor?
+    private let monitorQueue = DispatchQueue(label: "chat.bitchat.reachability")
+    #endif
+
+    init(debounceInterval: TimeInterval = 2.5, now: @escaping () -> Date = Date.init) {
+        self.now = now
+        self.debounce = ReachabilityDebounce(interval: debounceInterval, initial: true)
+        self.subject = CurrentValueSubject(true)
+    }
+
+    var isReachable: Bool { subject.value }
+
+    var reachabilityPublisher: AnyPublisher<Bool, Never> {
+        subject.removeDuplicates().dropFirst().eraseToAnyPublisher()
+    }
+
+    func start() {
+        guard !started else { return }
+        started = true
+        #if canImport(Network)
+        let monitor = NWPathMonitor()
+        self.monitor = monitor
+        monitor.pathUpdateHandler = { [weak self] path in
+            // Conservative: only "no interface at all" counts as unreachable.
+            let reachable = path.status != .unsatisfied
+            Task { @MainActor in
+                self?.ingest(reachable: reachable)
+            }
+        }
+        monitor.start(queue: monitorQueue)
+        #else
+        // No Network framework: never suppress startup.
+        #endif
+    }
+
+    /// Feed an observation into the debounce and publish committed changes.
+    /// Exposed internally so higher layers/tests could drive it if needed.
+    func ingest(reachable: Bool) {
+        flushWorkItem?.cancel()
+        flushWorkItem = nil
+        if let committed = debounce.observe(reachable: reachable, at: now()) {
+            publish(committed)
+        } else if debounce.hasPendingChange {
+            scheduleFlush()
+        }
+    }
+
+    private func scheduleFlush() {
+        let work = DispatchWorkItem { [weak self] in
+            guard let self else { return }
+            if let committed = self.debounce.flush(at: self.now()) {
+                self.publish(committed)
+            }
+        }
+        flushWorkItem = work
+        // Fire at the pending change's real deadline (pending.since + interval):
+        // duplicate path updates re-enter here and must not restart the window.
+        let delay = debounce.pendingRemaining(at: now()) ?? debounce.interval
+        DispatchQueue.main.asyncAfter(deadline: .now() + delay, execute: work)
+    }
+
+    private func publish(_ reachable: Bool) {
+        SecureLogger.info("NWPathReachabilityMonitor: network reachable -> \(reachable)", category: .session)
+        subject.send(reachable)
+    }
+}

bitchat/Services/NoiseEncryptionService.swift

@@ -172,6 +172,10 @@ final class NoiseEncryptionService {
     // Security components
     private let rateLimiter = NoiseRateLimiter()
     private let keychain: KeychainManagerProtocol
+
+    // One-time prekeys for forward-secret courier sealing (lazy generation
+    // inside the store; the batch is minted on first bundle build).
+    private let localPrekeys: LocalPrekeyStore
     
     // Session maintenance
     private var rekeyTimer: Timer?
@@ -200,6 +204,7 @@ final class NoiseEncryptionService {
     
     init(keychain: KeychainManagerProtocol) {
         self.keychain = keychain
+        self.localPrekeys = LocalPrekeyStore(keychain: keychain)
 
         // BCH-01-009: Load or create static identity key with proper error handling
         let loadedKey: Curve25519.KeyAgreement.PrivateKey
@@ -412,13 +417,111 @@ final class NoiseEncryptionService {
         }
         return (payload: payload, senderStaticKey: senderKey.rawRepresentation)
     }
-    
+
+    // MARK: - One-Time Prekey Envelopes (forward-secret Noise X)
+
+    /// Domain separation for prekey-sealed envelopes: distinct from both the
+    /// interactive XX transcripts and static-sealed courier envelopes, and
+    /// bound to the specific prekey ID so a ciphertext cannot be replayed
+    /// against a different prekey.
+    private static let prekeyProloguePrefix = Data("bitchat-prekey-v1".utf8)
+
+    private static func prekeyPrologue(for prekeyID: UInt32) -> Data {
+        var prologue = prekeyProloguePrefix
+        var big = prekeyID.bigEndian
+        withUnsafeBytes(of: &big) { prologue.append(contentsOf: $0) }
+        return prologue
+    }
+
+    /// Encrypt a payload to one of the recipient's gossiped one-time prekeys
+    /// (Noise X where the responder static is the prekey, not the identity
+    /// key). Unlike `sealCourierPayload`, this is forward secret: once the
+    /// recipient consumes the prekey and its grace window lapses, the private
+    /// key is deleted and captured ciphertext becomes undecryptable even if
+    /// the recipient's identity key is later compromised. The initiator's
+    /// static still rides inside (encrypted), so the recipient authenticates
+    /// the sender exactly as with static-sealed envelopes.
+    func sealPrekeyPayload(_ payload: Data, recipientPrekey: PrekeyBundle.Prekey) throws -> Data {
+        let remoteKey = try NoiseHandshakeState.validatePublicKey(recipientPrekey.publicKey)
+        let handshake = NoiseHandshakeState(
+            role: .initiator,
+            pattern: .X,
+            keychain: keychain,
+            localStaticKey: staticIdentityKey,
+            remoteStaticKey: remoteKey,
+            prologue: Self.prekeyPrologue(for: recipientPrekey.id)
+        )
+        return try handshake.writeMessage(payload: payload)
+    }
+
+    /// Decrypt an envelope sealed to one of our one-time prekeys. On success
+    /// the prekey is marked consumed (its private key survives a 48h grace
+    /// window for spray-and-wait redeliveries, then is deleted for good).
+    /// Returns the payload, the sender's authenticated static key (same
+    /// contract as `openCourierPayload`), and whether this open actually
+    /// retired the prekey — false for a redelivery of already-consumed mail —
+    /// so the caller can re-gossip the shrunken bundle only when it changed.
+    func openPrekeyPayload(_ envelopeCiphertext: Data, prekeyID: UInt32) throws -> (payload: Data, senderStaticKey: Data, consumedPrekey: Bool) {
+        guard let prekeyPrivate = localPrekeys.privateKey(for: prekeyID) else {
+            throw NoiseEncryptionError.unknownPrekey
+        }
+        let handshake = NoiseHandshakeState(
+            role: .responder,
+            pattern: .X,
+            keychain: keychain,
+            localStaticKey: prekeyPrivate,
+            prologue: Self.prekeyPrologue(for: prekeyID)
+        )
+        let payload = try handshake.readMessage(envelopeCiphertext)
+        guard let senderKey = handshake.getRemoteStaticPublicKey() else {
+            throw NoiseError.missingKeys
+        }
+        let consumedPrekey = localPrekeys.markConsumed(prekeyID)
+        return (payload: payload, senderStaticKey: senderKey.rawRepresentation, consumedPrekey: consumedPrekey)
+    }
+
+    /// Current signed prekey bundle for gossip, minting the initial batch on
+    /// first use. Nil only when signing fails.
+    func currentPrekeyBundle() -> PrekeyBundle? {
+        let (prekeys, generatedAt) = localPrekeys.currentBundlePrekeys()
+        guard !prekeys.isEmpty else { return nil }
+        let unsigned = PrekeyBundle(
+            noiseStaticPublicKey: getStaticPublicKeyData(),
+            prekeys: prekeys,
+            generatedAt: generatedAt,
+            signature: Data(count: PrekeyBundle.signatureLength)
+        )
+        guard let signature = signData(unsigned.signableBytes()) else { return nil }
+        return PrekeyBundle(
+            noiseStaticPublicKey: unsigned.noiseStaticPublicKey,
+            prekeys: prekeys,
+            generatedAt: generatedAt,
+            signature: signature
+        )
+    }
+
+    /// Verify a peer's bundle signature against their announce-bound Ed25519
+    /// signing key.
+    func verifyPrekeyBundleSignature(_ bundle: PrekeyBundle, signingPublicKey: Data) -> Bool {
+        verifySignature(bundle.signature, for: bundle.signableBytes(), publicKey: signingPublicKey)
+    }
+
+    /// Prune dead prekeys and top the batch back up when consumption runs it
+    /// low. Returns true when the published bundle changed and should be
+    /// re-gossiped.
+    @discardableResult
+    func replenishPrekeysIfNeeded() -> Bool {
+        localPrekeys.replenishIfNeeded()
+    }
+
     /// Clear persistent identity (for panic mode)
     func clearPersistentIdentity() {
         // Clear from keychain
         let deletedStatic = keychain.deleteIdentityKey(forKey: "noiseStaticKey")
         let deletedSigning = keychain.deleteIdentityKey(forKey: "ed25519SigningKey")
         SecureLogger.logKeyOperation(.delete, keyType: "identity keys", success: deletedStatic && deletedSigning)
+        // One-time prekey privates go with the identity they were bound to.
+        localPrekeys.wipe()
         SecureLogger.warning("Panic mode activated - identity cleared", category: .security)
         // Stop rekey timer
         stopRekeyTimer()
@@ -812,4 +915,7 @@ struct NoiseMessage: Codable {
 enum NoiseEncryptionError: Error {
     case handshakeRequired
     case sessionNotEstablished
+    /// Envelope references a prekey ID we don't hold (never ours, already
+    /// deleted after its grace window, or wiped in a panic).
+    case unknownPrekey
 }

bitchat/Services/NostrProcessedEventStore.swift

@@ -0,0 +1,106 @@
+//
+// NostrProcessedEventStore.swift
+// bitchat
+//
+// This is free and unencumbered software released into the public domain.
+// For more information, see <https://unlicense.org>
+//
+
+import BitLogger
+import Foundation
+
+/// Disk persistence for processed gift-wrap event IDs. NIP-59 randomizes
+/// gift-wrap timestamps, so DM subscriptions must look back generously (24h)
+/// and relays redeliver the same events on every launch — without a
+/// cross-launch record, each relaunch reprocesses old PMs and acks
+/// (re-sent DELIVERED bursts, "delivered ack for unknown mid" noise).
+///
+/// Contents are event IDs already visible to every relay, so
+/// until-first-unlock file protection is the right at-rest posture — the
+/// file must also load during a locked-background restoration relaunch.
+/// Wiped on panic via the dedup service's clear paths.
+final class NostrProcessedEventStore {
+    private let fileURL: URL?
+    // All file access is serialized here: appends are read-modify-write, and
+    // overlapping debounced flushes would otherwise race and drop IDs.
+    private let ioQueue = DispatchQueue(label: "chat.bitchat.nostr-processed-events", qos: .utility)
+
+    init(fileURL: URL? = nil) {
+        self.fileURL = fileURL ?? Self.defaultFileURL()
+    }
+
+    /// Processed event IDs, oldest first (insertion order).
+    func load() -> [String] {
+        ioQueue.sync { loadLocked() }
+    }
+
+    /// Merge new IDs onto the persisted record, oldest-first, trimming from
+    /// the front past `cap`. Append-merge (not snapshot-overwrite) so the
+    /// in-memory cache being cleared transiently (channel switches) can
+    /// never shrink the on-disk record.
+    func append(_ newIDs: [String], cap: Int) {
+        guard !newIDs.isEmpty else { return }
+        ioQueue.async { [self] in
+            var merged = loadLocked()
+            var known = Set(merged)
+            for id in newIDs where !known.contains(id) {
+                merged.append(id)
+                known.insert(id)
+            }
+            if merged.count > cap {
+                merged.removeFirst(merged.count - cap)
+            }
+            saveLocked(merged)
+        }
+    }
+
+    func wipe() {
+        ioQueue.async { [self] in
+            guard let fileURL else { return }
+            try? FileManager.default.removeItem(at: fileURL)
+        }
+    }
+
+    private func loadLocked() -> [String] {
+        guard let fileURL,
+              let data = try? Data(contentsOf: fileURL),
+              let ids = try? JSONDecoder().decode([String].self, from: data) else {
+            return []
+        }
+        return ids
+    }
+
+    private func saveLocked(_ eventIDs: [String]) {
+        guard let fileURL else { return }
+        guard !eventIDs.isEmpty else {
+            try? FileManager.default.removeItem(at: fileURL)
+            return
+        }
+        do {
+            try FileManager.default.createDirectory(
+                at: fileURL.deletingLastPathComponent(),
+                withIntermediateDirectories: true
+            )
+            let data = try JSONEncoder().encode(eventIDs)
+            var options: Data.WritingOptions = [.atomic]
+            #if os(iOS)
+            options.insert(.completeFileProtectionUntilFirstUserAuthentication)
+            #endif
+            try data.write(to: fileURL, options: options)
+        } catch {
+            SecureLogger.error("Failed to persist processed Nostr events: \(error)", category: .session)
+        }
+    }
+
+    private static func defaultFileURL() -> URL? {
+        guard let base = try? FileManager.default.url(
+            for: .applicationSupportDirectory,
+            in: .userDomainMask,
+            appropriateFor: nil,
+            create: true
+        ) else { return nil }
+        return base
+            .appendingPathComponent("nostr", isDirectory: true)
+            .appendingPathComponent("processed-events.json")
+    }
+}

bitchat/Services/NostrTransport.swift

@@ -19,6 +19,36 @@ final class NostrTransport: Transport, @unchecked Sendable {
         /// doesn't count: DM sends target the default relay set and would
         /// still queue.
         let relayConnectivity: @MainActor () -> AnyPublisher<Bool, Never>
+        /// Paces outbound acks. Defaults to an isolated pacer so tests don't
+        /// serialize behind each other; `live` passes the process-wide one.
+        let ackPacer: AckPacer
+
+        init(
+            notificationCenter: NotificationCenter,
+            loadFavorites: @escaping @MainActor () -> [Data: FavoritesPersistenceService.FavoriteRelationship],
+            favoriteStatusForNoiseKey: @escaping @MainActor (Data) -> FavoritesPersistenceService.FavoriteRelationship?,
+            favoriteStatusForPeerID: @escaping @MainActor (PeerID) -> FavoritesPersistenceService.FavoriteRelationship?,
+            currentIdentity: @escaping @MainActor () throws -> NostrIdentity?,
+            registerPendingGiftWrap: @escaping @MainActor (String) -> Void,
+            sendEvent: @escaping @MainActor (NostrEvent) -> Void,
+            scheduleAfter: @escaping @Sendable (TimeInterval, @escaping @Sendable () -> Void) -> Void,
+            relayConnectivity: @escaping @MainActor () -> AnyPublisher<Bool, Never>,
+            ackPacer: AckPacer? = nil
+        ) {
+            self.notificationCenter = notificationCenter
+            self.loadFavorites = loadFavorites
+            self.favoriteStatusForNoiseKey = favoriteStatusForNoiseKey
+            self.favoriteStatusForPeerID = favoriteStatusForPeerID
+            self.currentIdentity = currentIdentity
+            self.registerPendingGiftWrap = registerPendingGiftWrap
+            self.sendEvent = sendEvent
+            self.scheduleAfter = scheduleAfter
+            self.relayConnectivity = relayConnectivity
+            // Default pacer drives its throttle through the same injected
+            // scheduler, so tests that step scheduleAfter manually keep
+            // control of the ack cadence.
+            self.ackPacer = ackPacer ?? AckPacer(scheduleAfter: scheduleAfter)
+        }
 
         @MainActor
         static func live(idBridge: NostrIdentityBridge) -> Dependencies {
@@ -33,7 +63,8 @@ final class NostrTransport: Transport, @unchecked Sendable {
                 scheduleAfter: { delay, action in
                     DispatchQueue.main.asyncAfter(deadline: .now() + delay, execute: action)
                 },
-                relayConnectivity: { NostrRelayManager.shared.$isDMRelayConnected.eraseToAnyPublisher() }
+                relayConnectivity: { NostrRelayManager.shared.$isDMRelayConnected.eraseToAnyPublisher() },
+                ackPacer: NostrTransport.sharedAckPacer
             )
         }
     }
@@ -41,14 +72,64 @@ final class NostrTransport: Transport, @unchecked Sendable {
     // Provide BLE short peer ID for BitChat embedding
     var senderPeerID = PeerID(str: "")
 
-    // Throttle READ receipts to avoid relay rate limits
-    private struct QueuedRead {
-        let receipt: ReadReceipt
-        let peerID: PeerID
+    // Throttle outbound acks — READ receipts and DELIVERED acks, direct and
+    // geohash — to avoid relay rate limits. Reconnect redelivery produces a
+    // burst of acks at once: 8 DELIVERED in under a second tripped damus's
+    // "noting too much" during July 2026 device testing.
+    private enum QueuedAck {
+        case readDirect(ReadReceipt, PeerID)
+        case deliveredDirect(messageID: String, peerID: PeerID)
+        case deliveredGeohash(messageID: String, recipientHex: String, identity: NostrIdentity)
+        case readGeohash(messageID: String, recipientHex: String, identity: NostrIdentity)
     }
-    private var readQueue: [QueuedRead] = []
-    private var isSendingReadAcks = false
-    private let readAckInterval: TimeInterval = TransportConfig.nostrReadAckInterval
+
+    /// Ack pacing shared across transport instances. Geohash acks are sent
+    /// through short-lived transports created per ack
+    /// (`makeGeohashNostrTransport()`), so a per-instance queue would only
+    /// ever hold one item and never pace a burst (flagged by Codex on
+    /// #1398). Production wires `sharedAckPacer` via `Dependencies.live`;
+    /// tests get an isolated instance per `Dependencies` by default.
+    /// @unchecked Sendable: all mutable state (`pending`, `isSending`) is
+    /// confined to the serial `queue`; the class is only touched via
+    /// `enqueue` and the scheduler callback, both of which hop onto it.
+    final class AckPacer: @unchecked Sendable {
+        typealias Scheduler = @Sendable (TimeInterval, @escaping @Sendable () -> Void) -> Void
+
+        private let queue = DispatchQueue(label: "chat.bitchat.nostr-ack-pacer")
+        private var pending: [() -> Void] = []
+        private var isSending = false
+        private let interval: TimeInterval = TransportConfig.nostrReadAckInterval
+        private let scheduleAfter: Scheduler
+
+        init(scheduleAfter: @escaping Scheduler = { delay, action in
+            DispatchQueue.global(qos: .utility).asyncAfter(deadline: .now() + delay, execute: action)
+        }) {
+            self.scheduleAfter = scheduleAfter
+        }
+
+        func enqueue(_ send: @escaping () -> Void) {
+            queue.async {
+                self.pending.append(send)
+                self.processNext()
+            }
+        }
+
+        /// Must be called on `queue`.
+        private func processNext() {
+            guard !isSending, !pending.isEmpty else { return }
+            isSending = true
+            let send = pending.removeFirst()
+            send()
+            scheduleAfter(interval) { [weak self] in
+                guard let self else { return }
+                self.queue.async {
+                    self.isSending = false
+                    self.processNext()
+                }
+            }
+        }
+    }
+    static let sharedAckPacer = AckPacer()
     private let keychain: KeychainManagerProtocol
     private let idBridge: NostrIdentityBridge
     private let dependencies: Dependencies
@@ -187,12 +268,14 @@ final class NostrTransport: Transport, @unchecked Sendable {
     }
 
     func sendReadReceipt(_ receipt: ReadReceipt, to peerID: PeerID) {
-        // Enqueue and process with throttling to avoid relay rate limits
-        // Use barrier to synchronize access to readQueue
-        queue.async(flags: .barrier) {
-            self.readQueue.append(QueuedRead(receipt: receipt, peerID: peerID))
-            self.processReadQueueIfNeeded()
-        }
+        enqueueAck(.readDirect(receipt, peerID))
+    }
+
+    /// Enqueue an ack for paced sending. Captures self strongly on purpose:
+    /// geohash acks ride throwaway transport instances that must stay alive
+    /// until their ack leaves the queue.
+    private func enqueueAck(_ ack: QueuedAck) {
+        dependencies.ackPacer.enqueue { self.sendAckItem(ack) }
     }
 
     func sendFavoriteNotification(to peerID: PeerID, isFavorite: Bool) {
@@ -212,17 +295,7 @@ final class NostrTransport: Transport, @unchecked Sendable {
 
     func sendBroadcastAnnounce() { /* no-op for Nostr */ }
     func sendDeliveryAck(for messageID: String, to peerID: PeerID) {
-        Task { @MainActor in
-            guard let recipientNpub = resolveRecipientNpub(for: peerID),
-                  let recipientHex = npubToHex(recipientNpub),
-                  let senderIdentity = try? dependencies.currentIdentity() else { return }
-            SecureLogger.debug("NostrTransport: preparing DELIVERED ack id=\(messageID.prefix(8))…", category: .session)
-            guard let ack = NostrEmbeddedBitChat.encodeAckForNostr(type: .delivered, messageID: messageID, recipientPeerID: peerID, senderPeerID: senderPeerID) else {
-                SecureLogger.error("NostrTransport: failed to embed DELIVERED ack", category: .session)
-                return
-            }
-            sendWrappedMessage(content: ack, recipientHex: recipientHex, senderIdentity: senderIdentity)
-        }
+        enqueueAck(.deliveredDirect(messageID: messageID, peerID: peerID))
     }
 }
 
@@ -232,19 +305,11 @@ extension NostrTransport {
 
     // MARK: Geohash ACK helpers
     func sendDeliveryAckGeohash(for messageID: String, toRecipientHex recipientHex: String, from identity: NostrIdentity) {
-        Task { @MainActor in
-            SecureLogger.debug("GeoDM: send DELIVERED mid=\(messageID.prefix(8))…", category: .session)
-            guard let embedded = NostrEmbeddedBitChat.encodeAckForNostrNoRecipient(type: .delivered, messageID: messageID, senderPeerID: senderPeerID) else { return }
-            sendWrappedMessage(content: embedded, recipientHex: recipientHex, senderIdentity: identity, registerPending: true)
-        }
+        enqueueAck(.deliveredGeohash(messageID: messageID, recipientHex: recipientHex, identity: identity))
     }
 
     func sendReadReceiptGeohash(_ messageID: String, toRecipientHex recipientHex: String, from identity: NostrIdentity) {
-        Task { @MainActor in
-            SecureLogger.debug("GeoDM: send READ mid=\(messageID.prefix(8))…", category: .session)
-            guard let embedded = NostrEmbeddedBitChat.encodeAckForNostrNoRecipient(type: .readReceipt, messageID: messageID, senderPeerID: senderPeerID) else { return }
-            sendWrappedMessage(content: embedded, recipientHex: recipientHex, senderIdentity: identity, registerPending: true)
-        }
+        enqueueAck(.readGeohash(messageID: messageID, recipientHex: recipientHex, identity: identity))
     }
 
     // MARK: Geohash DMs (per-geohash identity)
@@ -290,36 +355,42 @@ extension NostrTransport {
         dependencies.sendEvent(event)
     }
 
-    /// Must be called within a barrier on `queue`
-    private func processReadQueueIfNeeded() {
-        guard !isSendingReadAcks else { return }
-        guard !readQueue.isEmpty else { return }
-        isSendingReadAcks = true
-        let item = readQueue.removeFirst()
-        sendReadAckItem(item)
-    }
 
-    /// Sends a single read ack item (called after extraction from queue within barrier)
-    private func sendReadAckItem(_ item: QueuedRead) {
+    /// Sends a single ack item (invoked by the pacer, one per interval)
+    private func sendAckItem(_ item: QueuedAck) {
         Task { @MainActor in
-            defer { scheduleNextReadAck() }
-            guard let recipientNpub = resolveRecipientNpub(for: item.peerID),
-                  let recipientHex = npubToHex(recipientNpub),
-                  let senderIdentity = try? dependencies.currentIdentity() else { return }
-            SecureLogger.debug("NostrTransport: preparing READ ack id=\(item.receipt.originalMessageID.prefix(8))…", category: .session)
-            guard let ack = NostrEmbeddedBitChat.encodeAckForNostr(type: .readReceipt, messageID: item.receipt.originalMessageID, recipientPeerID: item.peerID, senderPeerID: senderPeerID) else {
-                SecureLogger.error("NostrTransport: failed to embed READ ack", category: .session)
-                return
-            }
-            sendWrappedMessage(content: ack, recipientHex: recipientHex, senderIdentity: senderIdentity)
-        }
-    }
+            switch item {
+            case .readDirect(let receipt, let peerID):
+                guard let recipientNpub = resolveRecipientNpub(for: peerID),
+                      let recipientHex = npubToHex(recipientNpub),
+                      let senderIdentity = try? dependencies.currentIdentity() else { return }
+                SecureLogger.debug("NostrTransport: preparing READ ack id=\(receipt.originalMessageID.prefix(8))…", category: .session)
+                guard let ack = NostrEmbeddedBitChat.encodeAckForNostr(type: .readReceipt, messageID: receipt.originalMessageID, recipientPeerID: peerID, senderPeerID: senderPeerID) else {
+                    SecureLogger.error("NostrTransport: failed to embed READ ack", category: .session)
+                    return
+                }
+                sendWrappedMessage(content: ack, recipientHex: recipientHex, senderIdentity: senderIdentity)
 
-    private func scheduleNextReadAck() {
-        dependencies.scheduleAfter(readAckInterval) { [weak self] in
-            self?.queue.async(flags: .barrier) { [weak self] in
-                self?.isSendingReadAcks = false
-                self?.processReadQueueIfNeeded()
+            case .deliveredDirect(let messageID, let peerID):
+                guard let recipientNpub = resolveRecipientNpub(for: peerID),
+                      let recipientHex = npubToHex(recipientNpub),
+                      let senderIdentity = try? dependencies.currentIdentity() else { return }
+                SecureLogger.debug("NostrTransport: preparing DELIVERED ack id=\(messageID.prefix(8))…", category: .session)
+                guard let ack = NostrEmbeddedBitChat.encodeAckForNostr(type: .delivered, messageID: messageID, recipientPeerID: peerID, senderPeerID: senderPeerID) else {
+                    SecureLogger.error("NostrTransport: failed to embed DELIVERED ack", category: .session)
+                    return
+                }
+                sendWrappedMessage(content: ack, recipientHex: recipientHex, senderIdentity: senderIdentity)
+
+            case .deliveredGeohash(let messageID, let recipientHex, let identity):
+                SecureLogger.debug("GeoDM: send DELIVERED mid=\(messageID.prefix(8))…", category: .session)
+                guard let embedded = NostrEmbeddedBitChat.encodeAckForNostrNoRecipient(type: .delivered, messageID: messageID, senderPeerID: senderPeerID) else { return }
+                sendWrappedMessage(content: embedded, recipientHex: recipientHex, senderIdentity: identity, registerPending: true)
+
+            case .readGeohash(let messageID, let recipientHex, let identity):
+                SecureLogger.debug("GeoDM: send READ mid=\(messageID.prefix(8))…", category: .session)
+                guard let embedded = NostrEmbeddedBitChat.encodeAckForNostrNoRecipient(type: .readReceipt, messageID: messageID, senderPeerID: senderPeerID) else { return }
+                sendWrappedMessage(content: embedded, recipientHex: recipientHex, senderIdentity: identity, registerPending: true)
             }
         }
     }

bitchat/Services/Prekeys/LocalPrekeyStore.swift

@@ -0,0 +1,228 @@
+//
+// LocalPrekeyStore.swift
+// bitchat
+//
+// This is free and unencumbered software released into the public domain.
+// For more information, see <https://unlicense.org>
+//
+
+import BitFoundation
+import BitLogger
+import CryptoKit
+import Foundation
+
+/// Owns this device's one-time Curve25519 prekey private keys.
+///
+/// Privates persist in the Keychain (single blob, same protection class as
+/// the identity keys). A batch of `batchSize` unconsumed prekeys backs the
+/// gossiped bundle; when consumption drops the unconsumed count below
+/// `replenishThreshold`, the batch tops back up and the bundle's
+/// `generatedAt` bumps so peers replace their cached copy.
+///
+/// Redelivery grace: spray-and-wait means the same prekey-sealed ciphertext
+/// (or a re-seal of the same message to the same prekey ID) can arrive via
+/// several couriers days apart. A consumed prekey's private key is therefore
+/// retained for `consumedGraceSeconds` after first use and only then deleted.
+/// Tradeoff: during the grace window a compromise of the device still exposes
+/// mail sealed to that prekey — the forward-secrecy clock starts at deletion,
+/// not at first open. Refusing new ciphertexts while accepting redeliveries
+/// is not possible (the recipient cannot distinguish them), so the window is
+/// kept short and fixed.
+final class LocalPrekeyStore {
+    struct Record: Codable {
+        let id: UInt32
+        let privateKey: Data
+        let createdAt: Date
+        var consumedAt: Date?
+    }
+
+    private struct Persisted: Codable {
+        var records: [Record]
+        var nextID: UInt32
+        var generatedAt: UInt64
+    }
+
+    enum Policy {
+        static let batchSize = PrekeyBundle.maxPrekeys
+        static let replenishThreshold = 3
+        /// How long a consumed prekey private survives for duplicate courier
+        /// deliveries of mail sealed to it.
+        static let consumedGraceSeconds: TimeInterval = 48 * 60 * 60
+        /// Unconsumed prekeys older than this are rotated out: no honest
+        /// sender seals to a bundle that stale (see
+        /// `PrekeyBundleStore.Limits.maxBundleAgeForSealingSeconds`).
+        static let unconsumedRetentionSeconds: TimeInterval = 30 * 24 * 60 * 60
+    }
+
+    private static let keychainKey = "prekeysV1"
+
+    private let keychain: KeychainManagerProtocol
+    private let now: () -> Date
+    private let queue = DispatchQueue(label: "chat.bitchat.prekeys.local")
+
+    // Guarded by `queue`.
+    private var records: [Record] = []
+    private var nextID: UInt32 = 0
+    private var generatedAt: UInt64 = 0
+    private var loaded = false
+
+    init(keychain: KeychainManagerProtocol, now: @escaping () -> Date = Date.init) {
+        self.keychain = keychain
+        self.now = now
+    }
+
+    // MARK: - Bundle contents (public prekeys)
+
+    /// Unconsumed public prekeys for the gossiped bundle, generating the
+    /// initial batch on first use. Sorted by ID for canonical signing bytes.
+    func currentBundlePrekeys() -> (prekeys: [PrekeyBundle.Prekey], generatedAt: UInt64) {
+        queue.sync {
+            loadLocked()
+            _ = replenishLocked()
+            let prekeys = records
+                .filter { $0.consumedAt == nil }
+                .sorted { $0.id < $1.id }
+                .compactMap { record -> PrekeyBundle.Prekey? in
+                    guard let key = try? Curve25519.KeyAgreement.PrivateKey(rawRepresentation: record.privateKey) else { return nil }
+                    return PrekeyBundle.Prekey(id: record.id, publicKey: key.publicKey.rawRepresentation)
+                }
+            return (prekeys, generatedAt)
+        }
+    }
+
+    // MARK: - Opening (private prekeys)
+
+    /// Private key for a prekey ID: unconsumed, or consumed within the
+    /// redelivery grace window.
+    func privateKey(for id: UInt32) -> Curve25519.KeyAgreement.PrivateKey? {
+        queue.sync {
+            loadLocked()
+            let date = now()
+            guard let record = records.first(where: { $0.id == id }) else { return nil }
+            if let consumedAt = record.consumedAt,
+               date.timeIntervalSince(consumedAt) > Policy.consumedGraceSeconds {
+                return nil
+            }
+            return try? Curve25519.KeyAgreement.PrivateKey(rawRepresentation: record.privateKey)
+        }
+    }
+
+    /// Marks a prekey consumed (starts its grace clock). Idempotent: a
+    /// redelivery within the grace window does not restart the clock.
+    ///
+    /// Returns true when this call actually retired a prekey, i.e. the
+    /// published bundle shrank. Consuming a prekey drops it from
+    /// `currentBundlePrekeys()`, so `generatedAt` must advance strictly too:
+    /// otherwise peers that cached the old bundle reject the same-`generatedAt`
+    /// replacement in `PrekeyBundleStore.ingest`, keep assigning the consumed
+    /// ID, and their mail starts failing `unknownPrekey` once the 48h grace
+    /// lapses. The caller re-gossips on a true result.
+    @discardableResult
+    func markConsumed(_ id: UInt32) -> Bool {
+        queue.sync {
+            loadLocked()
+            guard let index = records.firstIndex(where: { $0.id == id }),
+                  records[index].consumedAt == nil else { return false }
+            records[index].consumedAt = now()
+            advanceGeneratedAtLocked()
+            persistLocked()
+            return true
+        }
+    }
+
+    /// Prunes dead prekeys and tops the unconsumed batch back up when it runs
+    /// low. Returns true when the published bundle changed (caller should
+    /// re-gossip).
+    @discardableResult
+    func replenishIfNeeded() -> Bool {
+        queue.sync {
+            loadLocked()
+            return replenishLocked()
+        }
+    }
+
+    var unconsumedCount: Int {
+        queue.sync {
+            loadLocked()
+            return records.filter { $0.consumedAt == nil }.count
+        }
+    }
+
+    /// Panic wipe: drop all prekey privates from memory and the Keychain.
+    func wipe() {
+        queue.sync {
+            records.removeAll()
+            nextID = 0
+            generatedAt = 0
+            loaded = true
+            _ = keychain.deleteIdentityKey(forKey: Self.keychainKey)
+        }
+    }
+
+    // MARK: - Internals (call only on `queue`)
+
+    private func replenishLocked() -> Bool {
+        let date = now()
+
+        // Consumed prekeys past the grace window are gone for good; stale
+        // unconsumed ones rotate out (their bundle is too old to seal to).
+        let recordsBefore = records.count
+        let unconsumedBefore = records.filter { $0.consumedAt == nil }.count
+        records.removeAll { record in
+            if let consumedAt = record.consumedAt {
+                return date.timeIntervalSince(consumedAt) > Policy.consumedGraceSeconds
+            }
+            return date.timeIntervalSince(record.createdAt) > Policy.unconsumedRetentionSeconds
+        }
+        // Only a change to the *unconsumed* set alters the published bundle;
+        // grace-expired consumed keys were never in it.
+        let unconsumed = records.filter { $0.consumedAt == nil }.count
+        var bundleChanged = unconsumed != unconsumedBefore
+
+        if unconsumed < Policy.replenishThreshold {
+            for _ in unconsumed..<Policy.batchSize {
+                let key = Curve25519.KeyAgreement.PrivateKey()
+                records.append(Record(id: nextID, privateKey: key.rawRepresentation, createdAt: date, consumedAt: nil))
+                nextID &+= 1
+            }
+            advanceGeneratedAtLocked()
+            bundleChanged = true
+            SecureLogger.debug("🔑 Replenished one-time prekeys (unconsumed was \(unconsumed))", category: .security)
+        }
+
+        if bundleChanged || records.count != recordsBefore { persistLocked() }
+        return bundleChanged
+    }
+
+    /// Advance `generatedAt` strictly monotonically. Uses wall-clock millis but
+    /// never repeats or regresses, so two changes within the same millisecond
+    /// still produce distinct, increasing stamps that peers' monotonic ingest
+    /// accepts.
+    private func advanceGeneratedAtLocked() {
+        let nowMillis = UInt64(max(0, now().timeIntervalSince1970 * 1000))
+        generatedAt = max(nowMillis, generatedAt &+ 1)
+    }
+
+    private func loadLocked() {
+        guard !loaded else { return }
+        loaded = true
+        guard let data = keychain.getIdentityKey(forKey: Self.keychainKey),
+              let persisted = try? JSONDecoder().decode(Persisted.self, from: data) else {
+            return
+        }
+        records = persisted.records
+        nextID = persisted.nextID
+        generatedAt = persisted.generatedAt
+    }
+
+    private func persistLocked() {
+        let persisted = Persisted(records: records, nextID: nextID, generatedAt: generatedAt)
+        guard let data = try? JSONEncoder().encode(persisted) else {
+            SecureLogger.error("Failed to encode prekey store", category: .keychain)
+            return
+        }
+        if !keychain.saveIdentityKey(data, forKey: Self.keychainKey) {
+            SecureLogger.error("Failed to persist prekey store", category: .keychain)
+        }
+    }
+}

bitchat/Services/Prekeys/PrekeyBundleStore.swift

@@ -0,0 +1,210 @@
+//
+// PrekeyBundleStore.swift
+// bitchat
+//
+// This is free and unencumbered software released into the public domain.
+// For more information, see <https://unlicense.org>
+//
+
+import BitFoundation
+import BitLogger
+import Foundation
+
+/// Signature-verified one-time prekey bundles received from other peers.
+///
+/// One bundle per Noise static key: a newer `generatedAt` replaces the cached
+/// copy, keeping the IDs we already sealed with marked used so a prekey is
+/// never reused across messages. Assignments are remembered per message ID so
+/// deposit retries of the same message re-use its prekey (and its budget)
+/// instead of burning a fresh one per courier.
+///
+/// Only public key material lives here; it persists to disk so a sender can
+/// prekey-seal for recipients met long ago. Included in the panic wipe.
+final class PrekeyBundleStore {
+    struct StoredBundle: Codable {
+        let noiseKey: Data
+        var generatedAt: UInt64
+        var prekeyIDs: [UInt32]
+        var prekeyPublicKeys: [Data]
+        /// IDs this device already sealed with (never reused).
+        var usedIDs: Set<UInt32>
+        /// messageID → prekey ID, so re-deposits of one message share one prekey.
+        var assignments: [String: UInt32]
+        var updatedAt: Date
+    }
+
+    enum Limits {
+        static let maxPeers = 200
+        /// Don't seal to bundles older than this: the owner may have rotated
+        /// the unconsumed keys out (see `LocalPrekeyStore.Policy`).
+        static let maxBundleAgeForSealingSeconds: TimeInterval = 7 * 24 * 60 * 60
+    }
+
+    static let shared = PrekeyBundleStore()
+
+    private var bundles: [Data: StoredBundle] = [:]
+    private let queue = DispatchQueue(label: "chat.bitchat.prekeys.bundles")
+    private let fileURL: URL?
+    private let maxPeers: Int
+    private let now: () -> Date
+
+    /// - Parameter fileURL: Overrides the on-disk location (tests). Ignored
+    ///   when `persistsToDisk` is false.
+    init(
+        persistsToDisk: Bool = true,
+        fileURL: URL? = nil,
+        maxPeers: Int = Limits.maxPeers,
+        now: @escaping () -> Date = Date.init
+    ) {
+        self.now = now
+        self.maxPeers = maxPeers
+        self.fileURL = persistsToDisk ? (fileURL ?? Self.defaultFileURL()) : nil
+        loadFromDisk()
+    }
+
+    // MARK: - Ingest
+
+    /// Stores a bundle whose signature the caller has already verified
+    /// against the owner's announce-bound signing key. Returns false when an
+    /// equal-or-newer bundle is already cached (nothing changed).
+    @discardableResult
+    func ingest(_ bundle: PrekeyBundle) -> Bool {
+        guard bundle.noiseStaticPublicKey.count == PrekeyBundle.keyLength,
+              !bundle.prekeys.isEmpty else { return false }
+        return queue.sync {
+            if let existing = bundles[bundle.noiseStaticPublicKey],
+               existing.generatedAt >= bundle.generatedAt {
+                return false
+            }
+            let previous = bundles[bundle.noiseStaticPublicKey]
+            let newIDs = Set(bundle.prekeys.map(\.id))
+            // Keep consumption state for IDs the fresh bundle still offers
+            // (a top-up keeps the owner's unconsumed keys); drop the rest.
+            let carriedUsed = (previous?.usedIDs ?? []).intersection(newIDs)
+            let carriedAssignments = (previous?.assignments ?? [:]).filter { newIDs.contains($0.value) }
+            bundles[bundle.noiseStaticPublicKey] = StoredBundle(
+                noiseKey: bundle.noiseStaticPublicKey,
+                generatedAt: bundle.generatedAt,
+                prekeyIDs: bundle.prekeys.map(\.id),
+                prekeyPublicKeys: bundle.prekeys.map(\.publicKey),
+                usedIDs: carriedUsed,
+                assignments: carriedAssignments,
+                updatedAt: now()
+            )
+            enforceCapLocked()
+            persistLocked()
+            return true
+        }
+    }
+
+    // MARK: - Sealing support
+
+    /// Whether an unexpired bundle with sealable prekeys is cached for a peer.
+    func hasUsableBundle(for noiseKey: Data) -> Bool {
+        queue.sync {
+            guard let bundle = bundles[noiseKey], isFreshLocked(bundle) else { return false }
+            return bundle.usedIDs.count < bundle.prekeyIDs.count
+        }
+    }
+
+    /// The prekey to seal a message with: the message's existing assignment if
+    /// any (re-deposits reuse it), else the lowest unused ID, which is then
+    /// marked used. Nil when no fresh bundle is cached or all its prekeys are
+    /// spent — callers fall back to static sealing.
+    func assignPrekey(messageID: String, recipientNoiseKey: Data) -> PrekeyBundle.Prekey? {
+        queue.sync {
+            guard var bundle = bundles[recipientNoiseKey], isFreshLocked(bundle) else { return nil }
+
+            if let assigned = bundle.assignments[messageID],
+               let index = bundle.prekeyIDs.firstIndex(of: assigned) {
+                return PrekeyBundle.Prekey(id: assigned, publicKey: bundle.prekeyPublicKeys[index])
+            }
+
+            guard let index = bundle.prekeyIDs.indices
+                .filter({ !bundle.usedIDs.contains(bundle.prekeyIDs[$0]) })
+                .min(by: { bundle.prekeyIDs[$0] < bundle.prekeyIDs[$1] }) else {
+                return nil
+            }
+            let id = bundle.prekeyIDs[index]
+            bundle.usedIDs.insert(id)
+            bundle.assignments[messageID] = id
+            bundle.updatedAt = now()
+            bundles[recipientNoiseKey] = bundle
+            persistLocked()
+            return PrekeyBundle.Prekey(id: id, publicKey: bundle.prekeyPublicKeys[index])
+        }
+    }
+
+    // MARK: - Maintenance
+
+    /// Panic wipe: drop all cached bundles from memory and disk.
+    func wipe() {
+        queue.sync {
+            bundles.removeAll()
+            if let fileURL {
+                try? FileManager.default.removeItem(at: fileURL)
+            }
+        }
+    }
+
+    // MARK: - Internals (call only on `queue`)
+
+    private func isFreshLocked(_ bundle: StoredBundle) -> Bool {
+        let ageSeconds = now().timeIntervalSince1970 - Double(bundle.generatedAt) / 1000
+        return ageSeconds <= Limits.maxBundleAgeForSealingSeconds
+    }
+
+    private func enforceCapLocked() {
+        while bundles.count > maxPeers {
+            guard let victim = bundles.min(by: { $0.value.updatedAt < $1.value.updatedAt }) else { return }
+            bundles.removeValue(forKey: victim.key)
+        }
+    }
+
+    private func persistLocked() {
+        guard let fileURL else { return }
+        do {
+            if bundles.isEmpty {
+                try? FileManager.default.removeItem(at: fileURL)
+                return
+            }
+            try FileManager.default.createDirectory(
+                at: fileURL.deletingLastPathComponent(),
+                withIntermediateDirectories: true
+            )
+            let data = try JSONEncoder().encode(Array(bundles.values))
+            var options: Data.WritingOptions = [.atomic]
+            #if os(iOS)
+            options.insert(.completeFileProtection)
+            #endif
+            try data.write(to: fileURL, options: options)
+        } catch {
+            SecureLogger.error("Failed to persist prekey bundle store: \(error)", category: .security)
+        }
+    }
+
+    private func loadFromDisk() {
+        guard let fileURL else { return }
+        queue.sync {
+            guard let data = try? Data(contentsOf: fileURL),
+                  let stored = try? JSONDecoder().decode([StoredBundle].self, from: data) else {
+                return
+            }
+            for bundle in stored where bundle.prekeyIDs.count == bundle.prekeyPublicKeys.count {
+                bundles[bundle.noiseKey] = bundle
+            }
+        }
+    }
+
+    private static func defaultFileURL() -> URL? {
+        guard let base = try? FileManager.default.url(
+            for: .applicationSupportDirectory,
+            in: .userDomainMask,
+            appropriateFor: nil,
+            create: true
+        ) else { return nil }
+        return base
+            .appendingPathComponent("prekeys", isDirectory: true)
+            .appendingPathComponent("bundles.json")
+    }
+}

bitchat/Services/RelayController.swift

@@ -19,6 +19,7 @@ struct RelayController {
                        isHandshake: Bool,
                        isAnnounce: Bool,
                        isRequestSync: Bool = false,
+                       isUrgentBoardPost: Bool = false,
                        degree: Int,
                        highDegreeThreshold: Int) -> RelayDecision {
         let ttlCap = min(ttl, TransportConfig.messageTTLDefault)
@@ -64,7 +65,7 @@ struct RelayController {
         // - Dense graphs: keep lower but still allow multi-hop bridging
         // - Thin chains (degree <= 2): every hop counts and flood cost is
         //   minimal, so relay at full incoming depth
-        // - Announces get a bit more headroom
+        // - Announces (and urgent board posts) get a bit more headroom
         let ttlLimit: UInt8 = {
             if degree >= highDegreeThreshold {
                 return max(UInt8(2), min(ttlCap, UInt8(5)))
@@ -72,7 +73,7 @@ struct RelayController {
             if degree <= 2 {
                 return ttlCap
             }
-            let preferred = UInt8(isAnnounce ? 7 : 6)
+            let preferred = UInt8((isAnnounce || isUrgentBoardPost) ? 7 : 6)
             return max(UInt8(2), min(ttlCap, preferred))
         }()
         let newTTL = ttlLimit &- 1

bitchat/Services/Transport.swift

@@ -31,10 +31,47 @@ struct TransportPeerSnapshot: Equatable, Hashable {
     }
 }
 
+/// Outcome of a `/ping` probe over the mesh.
+struct MeshPingResult: Equatable {
+    /// Round-trip time in milliseconds.
+    let rttMs: Int
+    /// Total hops to the peer (1 = directly connected), derived from the
+    /// pong's TTL decrements; nil when the reply carried inconsistent TTLs.
+    let hops: Int?
+}
+
+/// Undirected mesh link between two peers, normalized so `(a, b)` and
+/// `(b, a)` collapse to one edge.
+struct MeshTopologyEdge: Hashable {
+    let a: PeerID
+    let b: PeerID
+
+    init(_ first: PeerID, _ second: PeerID) {
+        if first < second {
+            a = first
+            b = second
+        } else {
+            a = second
+            b = first
+        }
+    }
+}
+
+/// Point-in-time view of the mesh graph learned from gossiped announces
+/// (each announce carries up to 10 `directNeighbors`).
+struct MeshTopologySnapshot: Equatable {
+    let localPeerID: PeerID
+    let nodes: [PeerID]
+    let edges: [MeshTopologyEdge]
+}
+
 enum TransportEvent: @unchecked Sendable {
     case messageReceived(BitchatMessage)
     case publicMessageReceived(peerID: PeerID, nickname: String, content: String, timestamp: Date, messageID: String?)
     case noisePayloadReceived(peerID: PeerID, type: NoisePayloadType, payload: Data, timestamp: Date)
+    /// Encrypted group broadcast (MessageType 0x25). Opaque here — the group
+    /// coordinator decrypts and authenticates against the roster.
+    case groupMessageReceived(payload: Data, timestamp: Date)
     case peerConnected(PeerID)
     case peerDisconnected(PeerID)
     case peerListUpdated([PeerID])
@@ -124,10 +161,43 @@ protocol Transport: AnyObject {
     // transport cannot courier (no connected courier, or unsupported).
     func sendCourierMessage(_ content: String, messageID: String, recipientNoiseKey: Data, via couriers: [PeerID]) -> Bool
 
+    // Private groups (mesh transports only): creator-signed state travels
+    // 1:1 over Noise sessions; group messages flood like public broadcasts.
+    func sendGroupInvite(_ statePayload: Data, to peerID: PeerID)
+    func sendGroupKeyUpdate(_ statePayload: Data, to peerID: PeerID)
+    func broadcastGroupMessage(_ envelope: Data)
+
+    // Bulletin board (mesh transports only): broadcast a pre-signed board
+    // payload (post or tombstone) so it spreads over relay and gossip sync.
+    func sendBoardPayload(_ payload: Data)
+
+    // Mesh diagnostics (optional for transports). Defaults are inert so
+    // queue-backed transports (e.g. NostrTransport) stay untouched.
+    /// Sends a directed ping probe; the completion fires exactly once on the
+    /// main actor with the measured result, or nil on timeout/unsupported.
+    func sendMeshPing(to peerID: PeerID, completion: @escaping @MainActor (MeshPingResult?) -> Void)
+    /// Estimated intermediate hops toward `peerID` from gossiped topology
+    /// ([] = direct link, nil = no known path).
+    func computeMeshPath(to peerID: PeerID) -> [PeerID]?
+    /// Current mesh graph for the topology map; nil when unsupported.
+    func currentMeshTopology() -> MeshTopologySnapshot?
+
     // QR verification (optional for transports)
     func sendVerifyChallenge(to peerID: PeerID, noiseKeyHex: String, nonceA: Data)
     func sendVerifyResponse(to peerID: PeerID, noiseKeyHex: String, nonceA: Data)
 
+    // Vouching / transitive verification (optional for transports)
+    /// Capabilities the peer advertised in its last verified announce;
+    /// empty for peers that predate the capabilities TLV.
+    func peerCapabilities(_ peerID: PeerID) -> PeerCapabilities
+    /// Sends an encoded vouch-attestation batch inside the Noise session.
+    func sendVouchAttestations(_ payload: Data, to peerID: PeerID)
+    /// Appends a peer-authenticated observer. Unlike
+    /// `installNoiseSessionCallbacks` this never touches the (single-slot)
+    /// handshake-required callback, so secondary features can observe
+    /// session establishment without disturbing the primary registration.
+    func addPeerAuthenticatedObserver(_ handler: @escaping (PeerID, String) -> Void)
+
     // Pending file management (BCH-01-002: files held in memory until user accepts)
     func acceptPendingFile(id: String) -> URL?
     func declinePendingFile(id: String)
@@ -153,7 +223,22 @@ extension Transport {
 
     func sendVerifyChallenge(to peerID: PeerID, noiseKeyHex: String, nonceA: Data) {}
     func sendVerifyResponse(to peerID: PeerID, noiseKeyHex: String, nonceA: Data) {}
+    func sendGroupInvite(_ statePayload: Data, to peerID: PeerID) {}
+    func sendGroupKeyUpdate(_ statePayload: Data, to peerID: PeerID) {}
+    func broadcastGroupMessage(_ envelope: Data) {}
+    func peerCapabilities(_ peerID: PeerID) -> PeerCapabilities { [] }
+    func sendVouchAttestations(_ payload: Data, to peerID: PeerID) {}
+    func addPeerAuthenticatedObserver(_ handler: @escaping (PeerID, String) -> Void) {}
     func sendCourierMessage(_ content: String, messageID: String, recipientNoiseKey: Data, via couriers: [PeerID]) -> Bool { false }
+    func sendBoardPayload(_ payload: Data) {}
+
+    // Mesh diagnostics are mesh-transport-only; other transports report
+    // "no reply"/"no path" rather than pretending to measure anything.
+    func sendMeshPing(to peerID: PeerID, completion: @escaping @MainActor (MeshPingResult?) -> Void) {
+        Task { @MainActor in completion(nil) }
+    }
+    func computeMeshPath(to peerID: PeerID) -> [PeerID]? { nil }
+    func currentMeshTopology() -> MeshTopologySnapshot? { nil }
     func sendFileBroadcast(_ packet: BitchatFilePacket, transferId: String) {}
     func sendFilePrivate(_ packet: BitchatFilePacket, to peerID: PeerID, transferId: String) {}
     func cancelTransfer(_ transferId: String) {}
@@ -186,6 +271,8 @@ extension BitchatDelegate {
             )
         case let .noisePayloadReceived(peerID, type, payload, timestamp):
             didReceiveNoisePayload(from: peerID, type: type, payload: payload, timestamp: timestamp)
+        case let .groupMessageReceived(payload, timestamp):
+            didReceiveGroupMessage(payload: payload, timestamp: timestamp)
         case .peerConnected(let peerID):
             didConnectToPeer(peerID)
         case .peerDisconnected(let peerID):

bitchat/Services/TransportConfig.swift

@@ -16,6 +16,11 @@ enum TransportConfig {
     static let bleFragmentRelayTtlCap: UInt8 = 7
     static let bleFragmentRelayTtlCapDense: UInt8 = 5       // Contain fragment floods in dense graphs
 
+    // Mesh diagnostics (/ping)
+    static let meshPingTimeoutSeconds: TimeInterval = 10    // Give up on a probe after this window
+    static let meshPingInboundMaxPerLink: Int = 5           // Inbound ping budget per ingress link (claimed sender is spoofable)...
+    static let meshPingInboundWindowSeconds: TimeInterval = 10 // ...per sliding window (anti-amplification)
+
     // UI / Storage Caps
     static let privateChatCap: Int = 1337
     static let meshTimelineCap: Int = 1337
@@ -208,6 +213,25 @@ enum TransportConfig {
     static let bleSubscriptionRateLimitWindowSeconds: TimeInterval = 60.0   // Window for tracking subscription attempts
     static let bleSubscriptionRateLimitMaxAttempts: Int = 5                 // Max attempts before extended cooldown
 
+    // Source routing (v2 directed packets)
+    // Longest path we will originate, in intermediate hops between us and the
+    // recipient. Keep small: every hop must be a fresh, confirmed, v2-capable
+    // node, and long stale paths fail more often than floods.
+    static let bleSourceRouteMaxIntermediateHops: Int = 4
+    // A routed send with no inbound traffic from the recipient within this
+    // window counts as a route failure.
+    static let bleSourceRouteConfirmationWindowSeconds: TimeInterval = 10.0
+    // After a route failure, directed sends to that recipient flood instead
+    // of routing until this lapses.
+    static let bleSourceRouteSuppressionSeconds: TimeInterval = 60.0
+
+    // Targeted fragment resync (REQUEST_SYNC fragmentIdFilter)
+    // A broadcast reassembly with no new fragment for this long is stalled
+    // and triggers a targeted REQUEST_SYNC naming its fragment stream.
+    static let bleFragmentResyncStallSeconds: TimeInterval = 5.0
+    // Minimum spacing between targeted resync requests for the same stream.
+    static let bleFragmentResyncRetrySeconds: TimeInterval = 10.0
+
     // Store-and-forward for directed packets at relays. Spooled packets retry
     // on each maintenance flush until the window lapses; a longer window lets
     // brief link gaps (walking between rooms, reconnect churn) heal themselves.
@@ -218,6 +242,16 @@ enum TransportConfig {
     static let bleDisconnectNotifyDebounceSeconds: TimeInterval = 0.9
     static let bleReconnectLogDebounceSeconds: TimeInterval = 2.0
 
+    // Background wake-on-proximity (iOS). Pending connects issued on
+    // backgrounding never expire at the OS level: the Bluetooth controller
+    // completes them whenever the peer reappears in range and relaunches the
+    // app via state restoration. Entries older than the BLE address-rotation
+    // window no longer map to a reachable address, so the cache prunes them.
+    static let bleRecentPeripheralCacheCap: Int = 16
+    static let bleRecentPeripheralMaxAgeSeconds: TimeInterval = 15 * 60
+    // Central slots kept free for connects driven by live background discovery
+    static let bleBackgroundPendingConnectSlotReserve: Int = 2
+
     // Weak-link cooldown after connection timeouts
     static let bleWeakLinkCooldownSeconds: TimeInterval = 30.0
     static let bleWeakLinkRSSICutoff: Int = -90
@@ -289,4 +323,16 @@ enum TransportConfig {
     // Cooldown between speculative multi-hop handovers of the same envelope
     // toward a recipient heard only via relayed announces.
     static let courierRemoteHandoverCooldownSeconds: TimeInterval = 10 * 60
+
+    // One-time prekey bundles (forward-secret courier sealing)
+    // Own gossip-sync round for bundles: modest cadence, bounded peer count,
+    // and a long freshness window so bundles persist mesh-wide while their
+    // owners are away.
+    static let syncPrekeyBundleCapacity: Int = 200
+    static let syncPrekeyBundleIntervalSeconds: TimeInterval = 60.0
+    static let syncPrekeyBundleMaxAgeSeconds: TimeInterval = 24 * 60 * 60
+    // Unforced re-broadcasts of our own (unchanged) bundle, piggybacked on
+    // announces, keep it alive in peers' gossip stores; changed bundles are
+    // sent immediately.
+    static let prekeyBundleRebroadcastSeconds: TimeInterval = 60 * 60
 }

bitchat/Sync/GossipSyncManager.swift

@@ -73,11 +73,22 @@ final class GossipSyncManager {
         var stalePeerTimeoutSeconds: TimeInterval = 60.0
         var fragmentCapacity: Int = 600
         var fileTransferCapacity: Int = 200
+        var groupMessageCapacity: Int = 200
         var fragmentSyncIntervalSeconds: TimeInterval = 30.0
         var fileTransferSyncIntervalSeconds: TimeInterval = 60.0
         var messageSyncIntervalSeconds: TimeInterval = 15.0
+        // Board posts are few but long-lived (days, until each post's own
+        // expiry), so they get a slow round with their own capacity instead
+        // of competing with the 15-minute message window.
+        var boardCapacity: Int = 200
+        var boardSyncIntervalSeconds: TimeInterval = 60.0
         var responseRateLimitMaxResponses: Int = 8
         var responseRateLimitWindowSeconds: TimeInterval = 30.0
+        // Prekey bundles: one per peer, own sync round, long freshness so
+        // bundles persist mesh-wide while their owners are offline.
+        var prekeyBundleCapacity: Int = 200
+        var prekeyBundleSyncIntervalSeconds: TimeInterval = 60.0
+        var prekeyBundleMaxAgeSeconds: TimeInterval = 24 * 60 * 60
     }
 
     private let myPeerID: PeerID
@@ -86,11 +97,22 @@ final class GossipSyncManager {
     private let archive: GossipMessageArchive?
     weak var delegate: Delegate?
 
+    /// Source of raw signed board packets (posts + tombstones). The board
+    /// store is the single owner of board retention (expiry, tombstones,
+    /// caps, persistence), so sync rounds query it instead of keeping a
+    /// second copy here. Must be thread-safe; set before `start()`.
+    var boardPacketsProvider: (() -> [BitchatPacket])?
+
     // Storage: broadcast packets by type, and latest announce per sender
     private var messages = PacketStore()
     private var fragments = PacketStore()
     private var fileTransfers = PacketStore()
+    private var groupMessages = PacketStore()
     private var latestAnnouncementByPeer: [PeerID: BitchatPacket] = [:]
+    // Latest verified prekey bundle per owner. Unlike announces, bundles are
+    // NOT dropped on leave/stale peer: their whole purpose is reaching a
+    // sender while the owner is away.
+    private var latestPrekeyBundleByPeer: [PeerID: (id: String, packet: BitchatPacket)] = [:]
     private var archiveDirty = false
 
     // Timer
@@ -111,7 +133,13 @@ final class GossipSyncManager {
         )
         var schedules: [SyncSchedule] = []
         if config.seenCapacity > 0 && config.messageSyncIntervalSeconds > 0 {
-            schedules.append(SyncSchedule(types: .publicMessages, interval: config.messageSyncIntervalSeconds, lastSent: .distantPast))
+            // Group messages ride the public-message cadence; old clients
+            // ignore the extended bit and answer with announces/messages only.
+            var messageTypes: SyncTypeFlags = .publicMessages
+            if config.groupMessageCapacity > 0 {
+                messageTypes.formUnion(.groupMessage)
+            }
+            schedules.append(SyncSchedule(types: messageTypes, interval: config.messageSyncIntervalSeconds, lastSent: .distantPast))
         }
         if config.fragmentCapacity > 0 && config.fragmentSyncIntervalSeconds > 0 {
             schedules.append(SyncSchedule(types: .fragment, interval: config.fragmentSyncIntervalSeconds, lastSent: .distantPast))
@@ -119,6 +147,12 @@ final class GossipSyncManager {
         if config.fileTransferCapacity > 0 && config.fileTransferSyncIntervalSeconds > 0 {
             schedules.append(SyncSchedule(types: .fileTransfer, interval: config.fileTransferSyncIntervalSeconds, lastSent: .distantPast))
         }
+        if config.prekeyBundleCapacity > 0 && config.prekeyBundleSyncIntervalSeconds > 0 {
+            schedules.append(SyncSchedule(types: .prekeyBundle, interval: config.prekeyBundleSyncIntervalSeconds, lastSent: .distantPast))
+        }
+        if config.boardCapacity > 0 && config.boardSyncIntervalSeconds > 0 {
+            schedules.append(SyncSchedule(types: .board, interval: config.boardSyncIntervalSeconds, lastSent: .distantPast))
+        }
         syncSchedules = schedules
 
         if archive != nil {
@@ -149,12 +183,21 @@ final class GossipSyncManager {
             guard let self = self else { return }
 
             var types: SyncTypeFlags = .publicMessages
+            if self.config.groupMessageCapacity > 0 {
+                types.formUnion(.groupMessage)
+            }
             if self.config.fragmentCapacity > 0 && self.config.fragmentSyncIntervalSeconds > 0 {
                 types.formUnion(.fragment)
             }
             if self.config.fileTransferCapacity > 0 && self.config.fileTransferSyncIntervalSeconds > 0 {
                 types.formUnion(.fileTransfer)
             }
+            if self.config.prekeyBundleCapacity > 0 && self.config.prekeyBundleSyncIntervalSeconds > 0 {
+                types.formUnion(.prekeyBundle)
+            }
+            if self.config.boardCapacity > 0 && self.config.boardSyncIntervalSeconds > 0 && self.boardPacketsProvider != nil {
+                types.formUnion(.board)
+            }
             self.sendRequestSync(to: peerID, types: types)
         }
     }
@@ -169,9 +212,17 @@ final class GossipSyncManager {
     // messages get the long town-crier window; fragments, file transfers and
     // announces keep the short one.
     private func isPacketFresh(_ packet: BitchatPacket) -> Bool {
-        let maxAgeSeconds = packet.type == MessageType.message.rawValue
-            ? config.publicMessageMaxAgeSeconds
-            : config.maxMessageAgeSeconds
+        // Group messages share the whole-message window: members off the mesh
+        // for a while should backfill their crew's history like public chat.
+        let maxAgeSeconds: TimeInterval
+        switch packet.type {
+        case MessageType.message.rawValue, MessageType.groupMessage.rawValue:
+            maxAgeSeconds = config.publicMessageMaxAgeSeconds
+        case MessageType.prekeyBundle.rawValue:
+            maxAgeSeconds = config.prekeyBundleMaxAgeSeconds
+        default:
+            maxAgeSeconds = config.maxMessageAgeSeconds
+        }
         let nowMs = UInt64(Date().timeIntervalSince1970 * 1000)
         let ageThresholdMs = UInt64(maxAgeSeconds * 1000)
 
@@ -224,6 +275,36 @@ final class GossipSyncManager {
             guard isPacketFresh(packet) else { return }
             let idHex = PacketIdUtil.computeId(packet).hexEncodedString()
             fileTransfers.insert(idHex: idHex, packet: packet, capacity: max(1, config.fileTransferCapacity))
+        case .groupMessage:
+            // Opaque ciphertext to non-members; carried and served like any
+            // other broadcast so members get backfill from any relay.
+            guard isBroadcastRecipient else { return }
+            guard isPacketFresh(packet) else { return }
+            let idHex = PacketIdUtil.computeId(packet).hexEncodedString()
+            groupMessages.insert(idHex: idHex, packet: packet, capacity: max(1, config.groupMessageCapacity))
+        case .prekeyBundle:
+            // Callers only feed verified bundles here (own bundles at send
+            // time, peers' after signature verification), so gossip never
+            // spreads a bundle this node couldn't attribute.
+            guard isBroadcastRecipient else { return }
+            guard isPacketFresh(packet) else { return }
+            // Key by the bundle's authenticated identity (its noise static key),
+            // NOT the unauthenticated packet senderID. Otherwise one valid
+            // bundle re-broadcast under many fabricated sender IDs would create
+            // one cache entry each and exhaust the per-owner cap, starving
+            // legitimate bundles. One owner ⇒ at most one entry.
+            guard let bundle = PrekeyBundle.decode(packet.payload) else { return }
+            let owner = PeerID(publicKey: bundle.noiseStaticPublicKey)
+            if let existing = latestPrekeyBundleByPeer[owner],
+               existing.packet.timestamp >= packet.timestamp {
+                return
+            }
+            // Bounded owner count; replacing a known owner's bundle is always
+            // allowed so the cap can't block refreshes.
+            guard latestPrekeyBundleByPeer[owner] != nil
+                    || latestPrekeyBundleByPeer.count < max(1, config.prekeyBundleCapacity) else { return }
+            let idHex = PacketIdUtil.computeId(packet).hexEncodedString()
+            latestPrekeyBundleByPeer[owner] = (id: idHex, packet: packet)
         default:
             break
         }
@@ -232,7 +313,7 @@ final class GossipSyncManager {
     private func sendPeriodicSync(for types: SyncTypeFlags) {
         // Unicast sync to connected peers to allow RSR attribution
         if let connectedPeers = delegate?.getConnectedPeers(), !connectedPeers.isEmpty {
-            SecureLogger.debug("Sending periodic sync to \(connectedPeers.count) connected peers", category: .sync)
+            SecureLogger.debug("Sending periodic sync (\(types.logDescription)) to \(connectedPeers.count) connected peers", category: .sync)
             for peerID in connectedPeers {
                 sendRequestSync(to: peerID, types: types)
             }
@@ -257,11 +338,29 @@ final class GossipSyncManager {
         delegate?.sendPacket(signed)
     }
 
-    private func sendRequestSync(to peerID: PeerID, types: SyncTypeFlags) {
+    /// Targeted fragment recovery: ask connected peers for the specific
+    /// fragment streams whose reassembly has stalled, instead of waiting on
+    /// the next periodic GCS fragment round to cover them.
+    func requestMissingFragments(fragmentIDs: [Data]) {
+        queue.async { [weak self] in
+            self?._requestMissingFragments(fragmentIDs)
+        }
+    }
+
+    private func _requestMissingFragments(_ fragmentIDs: [Data]) {
+        guard let filter = RequestSyncPacket.encodeFragmentIdFilter(fragmentIDs) else { return }
+        guard let connectedPeers = delegate?.getConnectedPeers(), !connectedPeers.isEmpty else { return }
+        SecureLogger.debug("Requesting \(fragmentIDs.count) stalled fragment stream(s) from \(connectedPeers.count) peer(s)", category: .sync)
+        for peerID in connectedPeers {
+            sendRequestSync(to: peerID, types: .fragment, fragmentIdFilter: filter)
+        }
+    }
+
+    private func sendRequestSync(to peerID: PeerID, types: SyncTypeFlags, fragmentIdFilter: String? = nil) {
         // Register the request for RSR validation
         requestSyncManager.registerRequest(to: peerID)
-        
-        let payload = buildGcsPayload(for: types)
+
+        let payload = buildGcsPayload(for: types, fragmentIdFilter: fragmentIdFilter)
         var recipient = Data()
         var temp = peerID.id
         while temp.count >= 2 && recipient.count < 8 {
@@ -338,9 +437,19 @@ final class GossipSyncManager {
         }
 
         if requestedTypes.contains(.fragment) {
+            // A fragment-ID filter narrows the diff to exactly the named
+            // fragment streams (targeted resync for stalled reassemblies)
+            // and bypasses the since-cursor for them; the GCS filter still
+            // excludes the pieces the requester already holds. Fragment
+            // payloads start with the 8-byte stream ID.
+            let fragmentIdFilter = RequestSyncPacket.decodeFragmentIdFilter(request.fragmentIdFilter)
             let frags = fragments.allPackets(isFresh: isPacketFresh)
             for pkt in frags {
-                if let since, pkt.timestamp < since { continue }
+                if let fragmentIdFilter {
+                    guard fragmentIdFilter.contains(Data(pkt.payload.prefix(8))) else { continue }
+                } else if let since, pkt.timestamp < since {
+                    continue
+                }
                 let idBytes = PacketIdUtil.computeId(pkt)
                 if !mightContain(idBytes) {
                     var toSend = pkt
@@ -364,10 +473,56 @@ final class GossipSyncManager {
                 }
             }
         }
+
+        if requestedTypes.contains(.groupMessage) {
+            let groupPkts = groupMessages.allPackets(isFresh: isPacketFresh)
+            for pkt in groupPkts {
+                if let since, pkt.timestamp < since { continue }
+                let idBytes = PacketIdUtil.computeId(pkt)
+                if !mightContain(idBytes) {
+                    var toSend = pkt
+                    toSend.ttl = 0
+                    toSend.isRSR = true // Mark as solicited response
+                    delegate?.sendPacket(to: peerID, packet: toSend)
+                }
+            }
+        }
+        // Like announces, prekey bundles are exempt from the since-cursor:
+        // there is at most one per owner (newer replaces older), so the
+        // resend cost is bounded and a joining peer must be able to learn
+        // bundles generated long before it arrived.
+        if requestedTypes.contains(.prekeyBundle) {
+            for (_, pair) in latestPrekeyBundleByPeer {
+                let (idHex, pkt) = pair
+                guard isPacketFresh(pkt) else { continue }
+                let idBytes = Data(hexString: idHex) ?? Data()
+                if !mightContain(idBytes) {
+                    var toSend = pkt
+                    toSend.ttl = 0
+                    toSend.isRSR = true // Mark as solicited response
+                    delegate?.sendPacket(to: peerID, packet: toSend)
+                }
+            }
+        }
+        if requestedTypes.contains(.boardPost) {
+            // The board store already filters to live posts and tombstones;
+            // no freshness window applies (posts sync until their own expiry).
+            let boardPackets = boardPacketsProvider?() ?? []
+            for pkt in boardPackets {
+                if let since, pkt.timestamp < since { continue }
+                let idBytes = PacketIdUtil.computeId(pkt)
+                if !mightContain(idBytes) {
+                    var toSend = pkt
+                    toSend.ttl = 0
+                    toSend.isRSR = true // Mark as solicited response
+                    delegate?.sendPacket(to: peerID, packet: toSend)
+                }
+            }
+        }
     }
 
     // Build REQUEST_SYNC payload using current candidates and GCS params
-    private func buildGcsPayload(for types: SyncTypeFlags) -> Data {
+    private func buildGcsPayload(for types: SyncTypeFlags, fragmentIdFilter: String? = nil) -> Data {
         var candidates: [BitchatPacket] = []
         if types.contains(.announce) {
             for (_, pkt) in latestAnnouncementByPeer where isPacketFresh(pkt) {
@@ -383,9 +538,20 @@ final class GossipSyncManager {
         if types.contains(.fileTransfer) {
             candidates.append(contentsOf: fileTransfers.allPackets(isFresh: isPacketFresh))
         }
+        if types.contains(.groupMessage) {
+            candidates.append(contentsOf: groupMessages.allPackets(isFresh: isPacketFresh))
+        }
+        if types.contains(.prekeyBundle) {
+            for (_, pair) in latestPrekeyBundleByPeer where isPacketFresh(pair.packet) {
+                candidates.append(pair.packet)
+            }
+        }
+        if types.contains(.boardPost) {
+            candidates.append(contentsOf: boardPacketsProvider?() ?? [])
+        }
         if candidates.isEmpty {
             let p = GCSFilter.deriveP(targetFpr: config.gcsTargetFpr)
-            let req = RequestSyncPacket(p: p, m: 1, data: Data(), types: types)
+            let req = RequestSyncPacket(p: p, m: 1, data: Data(), types: types, fragmentIdFilter: fragmentIdFilter)
             return req.encode()
         }
 
@@ -399,12 +565,16 @@ final class GossipSyncManager {
             cap = max(1, config.fragmentCapacity)
         } else if types == .fileTransfer {
             cap = max(1, config.fileTransferCapacity)
+        } else if types == .prekeyBundle {
+            cap = max(1, config.prekeyBundleCapacity)
+        } else if types == .board {
+            cap = max(1, config.boardCapacity)
         } else {
             cap = max(1, config.seenCapacity)
         }
         let takeN = min(candidates.count, min(nMax, cap))
         if takeN <= 0 {
-            let req = RequestSyncPacket(p: p, m: 1, data: Data(), types: types)
+            let req = RequestSyncPacket(p: p, m: 1, data: Data(), types: types, fragmentIdFilter: fragmentIdFilter)
             return req.encode()
         }
         let included = Array(candidates.prefix(takeN))
@@ -422,7 +592,7 @@ final class GossipSyncManager {
         let sinceTimestamp: UInt64? = (covered < candidates.count && covered > 0)
             ? included[covered - 1].timestamp
             : nil
-        let req = RequestSyncPacket(p: params.p, m: params.m, data: params.data, types: types, sinceTimestamp: sinceTimestamp)
+        let req = RequestSyncPacket(p: params.p, m: params.m, data: params.data, types: types, sinceTimestamp: sinceTimestamp, fragmentIdFilter: fragmentIdFilter)
         return req.encode()
     }
 
@@ -440,6 +610,10 @@ final class GossipSyncManager {
         }
         fragments.removeExpired(isFresh: isPacketFresh)
         fileTransfers.removeExpired(isFresh: isPacketFresh)
+        groupMessages.removeExpired(isFresh: isPacketFresh)
+        latestPrekeyBundleByPeer = latestPrekeyBundleByPeer.filter { _, pair in
+            isPacketFresh(pair.packet)
+        }
     }
 
     // MARK: - Archive (public message persistence)
@@ -490,6 +664,9 @@ final class GossipSyncManager {
         // fragment traffic can't crowd messages out of the filter.
         for index in syncSchedules.indices {
             guard syncSchedules[index].interval > 0 else { continue }
+            // No board source wired up means nothing to offer or store;
+            // skip the round entirely.
+            if syncSchedules[index].types == .board && boardPacketsProvider == nil { continue }
             if syncSchedules[index].lastSent == .distantPast || now.timeIntervalSince(syncSchedules[index].lastSent) >= syncSchedules[index].interval {
                 syncSchedules[index].lastSent = now
                 sendPeriodicSync(for: syncSchedules[index].types)
@@ -527,6 +704,8 @@ final class GossipSyncManager {
     }
 
     private func removeState(for peerID: PeerID) {
+        // Deliberately keeps the peer's prekey bundle: bundles exist to reach
+        // owners who left the mesh, and they age out on their own schedule.
         _ = latestAnnouncementByPeer.removeValue(forKey: peerID)
         let messageCountBefore = messages.packets.count
         messages.remove { PeerID(hexData: $0.senderID) == peerID }
@@ -535,6 +714,7 @@ final class GossipSyncManager {
         }
         fragments.remove { PeerID(hexData: $0.senderID) == peerID }
         fileTransfers.remove { PeerID(hexData: $0.senderID) == peerID }
+        groupMessages.remove { PeerID(hexData: $0.senderID) == peerID }
     }
 }
 
@@ -552,6 +732,12 @@ extension GossipSyncManager {
         }
     }
 
+    func _hasPrekeyBundle(for peerID: PeerID) -> Bool {
+        queue.sync {
+            latestPrekeyBundleByPeer[peerID] != nil
+        }
+    }
+
     func _messageCount(for peerID: PeerID) -> Int {
         queue.sync {
             messages.allPackets { _ in true }.filter { PeerID(hexData: $0.senderID) == peerID }.count

bitchat/Sync/SyncTypeFlags.swift

@@ -36,9 +36,29 @@ struct SyncTypeFlags: OptionSet {
         case .fragment: return 5
         case .requestSync: return 6
         case .fileTransfer: return 7
+        case .boardPost: return 8
+        // Extended bits are compat-safe by construction: `toData()` encodes
+        // the bitfield little-endian with trailing zero bytes trimmed (bit 10
+        // widens the wire form from 1 to 2 bytes inside the length-prefixed
+        // REQUEST_SYNC TLV 0x04), and `decode(_:)` accepts 1...8 bytes while
+        // `type(forBit:)` maps unknown bits to nil — so old clients simply
+        // ignore the group bit and answer with the types they know.
+        case .groupMessage: return 10
         // Courier envelopes are directed deposits between trusted peers and
         // must never spread via gossip sync.
         case .courierEnvelope: return nil
+        // Ping/pong are ephemeral directed probes; replaying them via gossip
+        // sync would only produce stale, unanswerable echoes.
+        case .ping, .pong: return nil
+        // Gateway carriers are ephemeral live traffic (uplinks are directed,
+        // downlinks are rate-budgeted rebroadcasts); replaying them via sync
+        // would waste airtime and extend their lifetime.
+        case .nostrCarrier: return nil
+        // Prekey bundles gossip like board posts. The bitfield is a
+        // wire-tolerant little-endian UInt64 (1-8 bytes, unknown high bits
+        // ignored by `type(forBit:)`), so bits 8+ need no format change: old
+        // clients decode the wider flags and simply never match the new bits.
+        case .prekeyBundle: return 9
         }
     }
 
@@ -52,6 +72,12 @@ struct SyncTypeFlags: OptionSet {
         case 5: return .fragment
         case 6: return .requestSync
         case 7: return .fileTransfer
+        // Bit 8 spills the encoded bitfield into a second byte. Decoders since
+        // type-aware sync (#853) accept 1-8 bytes and map unknown bits to no
+        // known type, so old clients ignore board rounds instead of choking.
+        case 8: return .boardPost
+        case 9: return .prekeyBundle
+        case 10: return .groupMessage
         default:
             return nil
         }
@@ -61,6 +87,9 @@ struct SyncTypeFlags: OptionSet {
     static let message = SyncTypeFlags(messageTypes: [.message])
     static let fragment = SyncTypeFlags(messageTypes: [.fragment])
     static let fileTransfer = SyncTypeFlags(messageTypes: [.fileTransfer])
+    static let board = SyncTypeFlags(messageTypes: [.boardPost])
+    static let prekeyBundle = SyncTypeFlags(messageTypes: [.prekeyBundle])
+    static let groupMessage = SyncTypeFlags(messageTypes: [.groupMessage])
 
     static let publicMessages = SyncTypeFlags(messageTypes: [.announce, .message])
 
@@ -86,6 +115,15 @@ struct SyncTypeFlags: OptionSet {
         SyncTypeFlags(rawValue: rawValue & other.rawValue)
     }
 
+    /// Compact form for logs, e.g. "message+fragment". Without this, the
+    /// per-schedule periodic sync rounds log identical lines and read as
+    /// duplicated sends (misdiagnosed twice during July 2026 device testing).
+    var logDescription: String {
+        let types = toMessageTypes()
+        guard !types.isEmpty else { return "none" }
+        return types.map { String(describing: $0) }.joined(separator: "+")
+    }
+
     func toMessageTypes() -> [MessageType] {
         guard rawValue != 0 else { return [] }
         var types: [MessageType] = []

bitchat/ViewModels/ChatGroupCoordinator.swift

@@ -0,0 +1,602 @@
+import BitFoundation
+import BitLogger
+import Foundation
+
+/// The narrow surface `ChatGroupCoordinator` needs from its owner.
+///
+/// Follows the `ChatDeliveryContext` exemplar: the coordinator depends on the
+/// minimal context it actually uses instead of holding an `unowned` back-ref
+/// to the whole `ChatViewModel`. Group chats are keyed like direct chats
+/// (virtual "group_" peer IDs), so the conversation intents below reuse the
+/// private-chat store operations.
+@MainActor
+protocol ChatGroupContext: AnyObject {
+    // MARK: Identity & state
+    var nickname: String { get }
+    var myPeerID: PeerID { get }
+    var selectedPrivateChatPeer: PeerID? { get }
+    var groupStore: GroupStore { get }
+
+    /// Fingerprint of our own Noise static identity key.
+    func myNoiseFingerprint() -> String
+    /// Our Ed25519 signing public key.
+    func mySigningPublicKey() -> Data
+    /// Signs `data` with our Noise signing key.
+    func signWithNoiseKey(_ data: Data) -> Data?
+
+    // MARK: Peers
+    func getPeerIDForNickname(_ nickname: String) -> PeerID?
+    func isPeerConnected(_ peerID: PeerID) -> Bool
+    func peerNickname(for peerID: PeerID) -> String?
+    /// The peer's Noise fingerprint from the live session/registry.
+    func meshFingerprint(for peerID: PeerID) -> String?
+    /// The peer's persisted crypto identity (fingerprint + signing key), if
+    /// the identity store has a signature-verified announce for them.
+    func cryptoIdentity(for peerID: PeerID) -> (fingerprint: String, signingKey: Data)?
+    /// The connected short peer ID whose fingerprint matches, if any.
+    func connectedPeerID(forFingerprint fingerprint: String) -> PeerID?
+    /// Whether the user has blocked the identity with this Noise fingerprint.
+    func isFingerprintBlocked(_ fingerprint: String) -> Bool
+
+    // MARK: Transport
+    func sendGroupInvitePayload(_ payload: Data, to peerID: PeerID)
+    func sendGroupKeyUpdatePayload(_ payload: Data, to peerID: PeerID)
+    func broadcastGroupMessagePayload(_ payload: Data)
+
+    // MARK: Conversation intents (group chats are direct-keyed)
+    @discardableResult
+    func appendPrivateMessage(_ message: BitchatMessage, to peerID: PeerID) -> Bool
+    func markPrivateChatUnread(_ peerID: PeerID)
+    func removePrivateChat(_ peerID: PeerID)
+    func startPrivateChat(with peerID: PeerID)
+    func endPrivateChat()
+    func addSystemMessage(_ content: String)
+    func addLocalPrivateSystemMessage(_ content: String, to peerID: PeerID)
+    func notifyUIChanged()
+    func notifyPrivateMessage(from senderName: String, message: String, peerID: PeerID)
+}
+
+extension ChatViewModel: ChatGroupContext {
+    // `nickname`, `myPeerID`, `selectedPrivateChatPeer`, `groupStore`,
+    // `getPeerIDForNickname(_:)`, `isPeerConnected(_:)`, `peerNickname(for:)`,
+    // `appendPrivateMessage(_:to:)`, `markPrivateChatUnread(_:)`,
+    // `removePrivateChat(_:)`, `startPrivateChat(with:)`,
+    // `addSystemMessage(_:)`, `addLocalPrivateSystemMessage(_:to:)`,
+    // `notifyUIChanged()`, and `notifyPrivateMessage(from:message:peerID:)`
+    // are shared requirements with the other contexts or satisfied by
+    // existing `ChatViewModel` members. The members below flatten nested
+    // service accesses into intent-named calls.
+
+    func myNoiseFingerprint() -> String {
+        meshService.noiseIdentityFingerprint()
+    }
+
+    func mySigningPublicKey() -> Data {
+        meshService.noiseSigningPublicKeyData()
+    }
+
+    func signWithNoiseKey(_ data: Data) -> Data? {
+        meshService.noiseSignData(data)
+    }
+
+    func meshFingerprint(for peerID: PeerID) -> String? {
+        meshService.getFingerprint(for: peerID)
+    }
+
+    /// The persisted, signature-verified identity behind a short mesh peer
+    /// ID. Cross-checked against the live session fingerprint so a roster
+    /// entry can never be pinned to a signing key from a different identity.
+    func cryptoIdentity(for peerID: PeerID) -> (fingerprint: String, signingKey: Data)? {
+        guard let fingerprint = meshService.getFingerprint(for: peerID) else { return nil }
+        let candidates = identityManager.getCryptoIdentitiesByPeerIDPrefix(peerID)
+        guard let identity = candidates.first(where: { $0.fingerprint == fingerprint }),
+              let signingKey = identity.signingPublicKey else { return nil }
+        return (fingerprint, signingKey)
+    }
+
+    /// Short mesh peer IDs are the fingerprint's first 16 hex chars, so the
+    /// connected peer for a roster fingerprint is a direct derivation.
+    func connectedPeerID(forFingerprint fingerprint: String) -> PeerID? {
+        let shortID = PeerID(str: String(fingerprint.prefix(16)))
+        return meshService.isPeerConnected(shortID) ? shortID : nil
+    }
+
+    func isFingerprintBlocked(_ fingerprint: String) -> Bool {
+        identityManager.isBlocked(fingerprint: fingerprint)
+    }
+
+    func sendGroupInvitePayload(_ payload: Data, to peerID: PeerID) {
+        meshService.sendGroupInvite(payload, to: peerID)
+    }
+
+    func sendGroupKeyUpdatePayload(_ payload: Data, to peerID: PeerID) {
+        meshService.sendGroupKeyUpdate(payload, to: peerID)
+    }
+
+    func broadcastGroupMessagePayload(_ payload: Data) {
+        meshService.broadcastGroupMessage(payload)
+    }
+
+    // MARK: CommandContextProvider group commands (parsed by CommandProcessor)
+
+    func groupCreate(named name: String) -> CommandResult {
+        groupCoordinator.createGroup(named: name)
+    }
+
+    func groupInvite(nickname: String) -> CommandResult {
+        groupCoordinator.inviteMember(nickname: nickname)
+    }
+
+    func groupRemove(nickname: String) -> CommandResult {
+        groupCoordinator.removeMember(nickname: nickname)
+    }
+
+    func groupLeave() -> CommandResult {
+        groupCoordinator.leaveGroup()
+    }
+
+    func groupList() -> CommandResult {
+        groupCoordinator.listGroups()
+    }
+}
+
+/// Owns the private-groups feature: creating groups, creator-managed invites
+/// and key rotation over Noise, and sealing/opening group message broadcasts.
+/// Delivery is fire-and-flood like public chat — no per-member acks in v1 —
+/// with gossip-sync backfill as the only offline catch-up.
+@MainActor
+final class ChatGroupCoordinator {
+    private unowned let context: any ChatGroupContext
+
+    private static let maxGroupNameLength = 40
+
+    init(context: any ChatGroupContext) {
+        self.context = context
+    }
+
+    // MARK: - Commands
+
+    func createGroup(named rawName: String) -> CommandResult {
+        let name = rawName.trimmed
+        guard !name.isEmpty else {
+            return .error(message: String(localized: "system.group.usage_create", comment: "Usage hint for /group create"))
+        }
+        guard name.count <= Self.maxGroupNameLength else {
+            return .error(message: String(localized: "system.group.name_too_long", comment: "Error when a group name exceeds the length cap"))
+        }
+
+        let myFingerprint = context.myNoiseFingerprint()
+        let mySigningKey = context.mySigningPublicKey()
+        guard !myFingerprint.isEmpty, mySigningKey.count == 32 else {
+            return .error(message: String(localized: "system.group.identity_unavailable", comment: "Error when the local identity is not ready for group operations"))
+        }
+
+        let creator = GroupMember(fingerprint: myFingerprint, signingKey: mySigningKey, nickname: context.nickname)
+        guard let group = context.groupStore.createGroup(named: name, creator: creator) else {
+            return .error(message: String(localized: "system.group.create_failed", comment: "Error when group creation fails"))
+        }
+
+        context.startPrivateChat(with: group.peerID)
+        return .success(message: String(
+            format: String(localized: "system.group.created", comment: "System message after creating a group; placeholder is the group name"),
+            locale: .current,
+            name
+        ))
+    }
+
+    func inviteMember(nickname rawNickname: String) -> CommandResult {
+        let nickname = normalizedNickname(rawNickname)
+        guard !nickname.isEmpty else {
+            return .error(message: String(localized: "system.group.usage_invite", comment: "Usage hint for /group invite"))
+        }
+        guard let group = selectedGroup() else {
+            return .error(message: String(localized: "system.group.not_in_group", comment: "Error when a group command requires an open group chat"))
+        }
+        guard group.creatorFingerprint == context.myNoiseFingerprint() else {
+            return .error(message: String(localized: "system.group.creator_only", comment: "Error when a non-creator attempts a creator-only group action"))
+        }
+        guard let peerID = context.getPeerIDForNickname(nickname) else {
+            return .error(message: String(
+                format: String(localized: "system.group.peer_not_found", comment: "Error when the invitee nickname is unknown; placeholder is the nickname"),
+                locale: .current,
+                nickname
+            ))
+        }
+        guard context.isPeerConnected(peerID) else {
+            return .error(message: String(
+                format: String(localized: "system.group.peer_not_connected", comment: "Error when the invitee is not connected over mesh; placeholder is the nickname"),
+                locale: .current,
+                nickname
+            ))
+        }
+        guard let identity = context.cryptoIdentity(for: peerID) else {
+            return .error(message: String(
+                format: String(localized: "system.group.peer_identity_unknown", comment: "Error when the invitee's verified identity is unavailable; placeholder is the nickname"),
+                locale: .current,
+                nickname
+            ))
+        }
+        guard !group.isMember(fingerprint: identity.fingerprint) else {
+            return .error(message: String(
+                format: String(localized: "system.group.already_member", comment: "Error when the invitee is already a member; placeholder is the nickname"),
+                locale: .current,
+                nickname
+            ))
+        }
+        guard group.members.count < BitchatGroup.maxMembers else {
+            return .error(message: String(
+                format: String(localized: "system.group.full", comment: "Error when the group is at the member cap; placeholder is the cap"),
+                locale: .current,
+                "\(BitchatGroup.maxMembers)"
+            ))
+        }
+
+        let newMember = GroupMember(
+            fingerprint: identity.fingerprint,
+            signingKey: identity.signingKey,
+            nickname: context.peerNickname(for: peerID) ?? nickname
+        )
+        // Rotate the key (epoch + 1) on every roster change, not just removals.
+        // A monotonically increasing epoch per roster gives the receiver a
+        // strict ordering: two out-of-order invite states can no longer share
+        // an epoch and last-writer-wins a just-added member back out.
+        let members = group.members + [newMember]
+        guard let (updated, key) = context.groupStore.rotateKey(groupID: group.groupID, members: members),
+              let payload = signedStatePayload(for: updated, key: key) else {
+            return .error(message: String(localized: "system.group.invite_failed", comment: "Error when building or signing a group invite fails"))
+        }
+
+        context.sendGroupInvitePayload(payload, to: peerID)
+        distributeState(payload, group: updated, excluding: [identity.fingerprint], type: .keyUpdate)
+
+        return .success(message: String(
+            format: String(localized: "system.group.invited", comment: "System message after inviting someone; placeholders are the nickname and the group name"),
+            locale: .current,
+            nickname,
+            updated.name
+        ))
+    }
+
+    /// Creator-side removal: rotates the group key (epoch + 1) and sends the
+    /// new state to every remaining member so the removed member's key stops
+    /// decrypting future traffic.
+    func removeMember(nickname rawNickname: String) -> CommandResult {
+        let nickname = normalizedNickname(rawNickname)
+        guard !nickname.isEmpty else {
+            return .error(message: String(localized: "system.group.usage_remove", comment: "Usage hint for /group remove"))
+        }
+        guard let group = selectedGroup() else {
+            return .error(message: String(localized: "system.group.not_in_group", comment: "Error when a group command requires an open group chat"))
+        }
+        guard group.creatorFingerprint == context.myNoiseFingerprint() else {
+            return .error(message: String(localized: "system.group.creator_only", comment: "Error when a non-creator attempts a creator-only group action"))
+        }
+        guard let member = group.members.first(where: { $0.nickname.caseInsensitiveCompare(nickname) == .orderedSame }) else {
+            return .error(message: String(
+                format: String(localized: "system.group.member_not_found", comment: "Error when the member to remove is not in the roster; placeholder is the nickname"),
+                locale: .current,
+                nickname
+            ))
+        }
+        guard member.fingerprint != group.creatorFingerprint else {
+            return .error(message: String(localized: "system.group.cannot_remove_creator", comment: "Error when the creator tries to remove themselves"))
+        }
+
+        let remaining = group.members.filter { $0.fingerprint != member.fingerprint }
+        guard let (rotated, newKey) = context.groupStore.rotateKey(groupID: group.groupID, members: remaining),
+              let payload = signedStatePayload(for: rotated, key: newKey) else {
+            return .error(message: String(localized: "system.group.rotate_failed", comment: "Error when rotating the group key fails"))
+        }
+
+        distributeState(payload, group: rotated, excluding: [], type: .keyUpdate)
+        notifyRemovedMember(member, rotated: rotated)
+
+        return .success(message: String(
+            format: String(localized: "system.group.removed_member", comment: "System message after removing a member and rotating the key; placeholder is the nickname"),
+            locale: .current,
+            member.nickname
+        ))
+    }
+
+    func leaveGroup() -> CommandResult {
+        guard let group = selectedGroup() else {
+            return .error(message: String(localized: "system.group.not_in_group", comment: "Error when a group command requires an open group chat"))
+        }
+        // Close the chat window first so the confirmation message doesn't
+        // resurrect the conversation we're about to remove.
+        context.endPrivateChat()
+        context.removePrivateChat(group.peerID)
+        context.groupStore.removeGroup(withID: group.groupID)
+        context.notifyUIChanged()
+        return .success(message: String(
+            format: String(localized: "system.group.left", comment: "System message after leaving a group; placeholder is the group name"),
+            locale: .current,
+            group.name
+        ))
+    }
+
+    func listGroups() -> CommandResult {
+        let groups = context.groupStore.groups
+        guard !groups.isEmpty else {
+            return .success(message: String(localized: "system.group.none", comment: "System message when the user is in no groups"))
+        }
+        let myFingerprint = context.myNoiseFingerprint()
+        let lines = groups.map { group -> String in
+            let role = group.creatorFingerprint == myFingerprint ? " (creator)" : ""
+            return "#\(group.name)\(role) — \(group.members.count)/\(BitchatGroup.maxMembers)"
+        }
+        return .success(message: String(localized: "system.group.list_header", comment: "Header line for the /group list output") + "\n" + lines.joined(separator: "\n"))
+    }
+
+    // MARK: - Sending
+
+    /// Fire-and-flood send: local echo goes straight to `.sent` because group
+    /// messages have no per-member acknowledgments in v1.
+    func sendGroupMessage(_ content: String, to groupPeerID: PeerID) {
+        guard !content.isEmpty, content.count <= InputValidator.Limits.maxMessageLength else { return }
+        guard let group = context.groupStore.group(for: groupPeerID),
+              let key = context.groupStore.key(forGroupID: group.groupID) else {
+            context.addSystemMessage(String(localized: "system.group.unknown", comment: "System message when sending into an unknown group"))
+            return
+        }
+
+        let messageID = UUID().uuidString
+        let timestamp = Date()
+        let payload: Data
+        do {
+            payload = try GroupCrypto.sealMessage(
+                content: content,
+                messageID: messageID,
+                senderNickname: context.nickname,
+                senderSigningKey: context.mySigningPublicKey(),
+                timestampMs: UInt64(timestamp.timeIntervalSince1970 * 1000),
+                groupID: group.groupID,
+                epoch: group.epoch,
+                key: key,
+                sign: { [weak context] data in context?.signWithNoiseKey(data) }
+            )
+        } catch {
+            SecureLogger.error("Failed to seal group message: \(error)", category: .encryption)
+            context.addLocalPrivateSystemMessage(
+                String(localized: "system.group.send_failed", comment: "System message when sealing a group message fails"),
+                to: groupPeerID
+            )
+            return
+        }
+
+        let message = BitchatMessage(
+            id: messageID,
+            sender: context.nickname,
+            content: content,
+            timestamp: timestamp,
+            isRelay: false,
+            originalSender: nil,
+            isPrivate: true,
+            recipientNickname: group.name,
+            senderPeerID: context.myPeerID,
+            mentions: nil,
+            deliveryStatus: .sent
+        )
+        context.appendPrivateMessage(message, to: groupPeerID)
+        context.broadcastGroupMessagePayload(payload)
+        context.notifyUIChanged()
+    }
+
+    // MARK: - Receiving
+
+    /// Decrypt-verify path for an incoming 0x25 broadcast. Drops silently for
+    /// unknown groups (non-members relay but never read), wrong epochs, bad
+    /// sender signatures, and senders missing from the pinned roster.
+    func handleGroupMessagePayload(_ payload: Data, timestamp: Date) {
+        guard let envelope = GroupMessageEnvelope.decode(payload) else { return }
+        guard let group = context.groupStore.group(withID: envelope.groupID) else { return }
+        guard envelope.epoch == group.epoch else {
+            SecureLogger.debug("Dropping group message with epoch \(envelope.epoch) (current \(group.epoch))", category: .encryption)
+            return
+        }
+        guard let key = context.groupStore.key(forGroupID: group.groupID) else { return }
+
+        let plaintext: GroupMessagePlaintext
+        do {
+            plaintext = try GroupCrypto.openMessage(envelope, key: key)
+        } catch {
+            SecureLogger.debug("Failed to open group message: \(error)", category: .encryption)
+            return
+        }
+
+        // Sender must be pinned in the creator-signed roster; key possession
+        // alone is not authorship.
+        guard let member = group.member(withSigningKey: plaintext.senderSigningKey) else {
+            SecureLogger.warning("Dropping group message from non-roster sender", category: .security)
+            return
+        }
+        // Our own broadcast echoed back via relay or sync replay.
+        guard plaintext.senderSigningKey != context.mySigningPublicKey() else { return }
+        // Honor /block inside groups too: drop display + notification for a
+        // blocked member, consistent with every other inbound path.
+        guard !context.isFingerprintBlocked(member.fingerprint) else {
+            SecureLogger.debug("Dropping group message from blocked member", category: .security)
+            return
+        }
+
+        let groupPeerID = group.peerID
+        // Trust the authenticated inner timestamp (clamped so a future-dated
+        // message cannot pin itself to the bottom of the timeline).
+        let messageDate = min(Date(timeIntervalSince1970: TimeInterval(plaintext.timestampMs) / 1000), Date())
+        let senderName = member.nickname.isEmpty ? plaintext.senderNickname : member.nickname
+        let senderPeerID = PeerID(str: String(member.fingerprint.prefix(16)))
+        let message = BitchatMessage(
+            id: plaintext.messageID,
+            sender: senderName,
+            content: plaintext.content,
+            timestamp: messageDate,
+            isRelay: false,
+            originalSender: nil,
+            isPrivate: true,
+            recipientNickname: group.name,
+            senderPeerID: senderPeerID,
+            mentions: nil
+        )
+
+        guard context.appendPrivateMessage(message, to: groupPeerID) else { return }
+
+        let isViewing = context.selectedPrivateChatPeer == groupPeerID
+        if !isViewing {
+            context.markPrivateChatUnread(groupPeerID)
+            let isRecent = Date().timeIntervalSince(messageDate) < 30
+            if isRecent {
+                context.notifyPrivateMessage(
+                    from: "\(senderName) @ \(group.name)",
+                    message: plaintext.content,
+                    peerID: groupPeerID
+                )
+            }
+        }
+        context.notifyUIChanged()
+    }
+
+    /// Accepts creator-signed group state arriving as an invite. The Noise
+    /// session peer must BE the creator, the signature must verify against
+    /// the creator key pinned in the roster, and we must be in the roster.
+    func handleGroupInvitePayload(from peerID: PeerID, payload: Data) {
+        applyGroupState(from: peerID, payload: payload, isInvite: true)
+    }
+
+    /// Accepts creator-signed state updates (rotation/roster). A state whose
+    /// roster no longer includes us means we were removed: drop the group.
+    func handleGroupKeyUpdatePayload(from peerID: PeerID, payload: Data) {
+        applyGroupState(from: peerID, payload: payload, isInvite: false)
+    }
+}
+
+private extension ChatGroupCoordinator {
+    enum StateSendType {
+        case invite
+        case keyUpdate
+    }
+
+    func normalizedNickname(_ raw: String) -> String {
+        let trimmed = raw.trimmed
+        return trimmed.hasPrefix("@") ? String(trimmed.dropFirst()) : trimmed
+    }
+
+    func selectedGroup() -> BitchatGroup? {
+        guard let selected = context.selectedPrivateChatPeer, selected.isGroup else { return nil }
+        return context.groupStore.group(for: selected)
+    }
+
+    func signedStatePayload(for group: BitchatGroup, key: Data) -> Data? {
+        GroupStatePayload.makeSigned(group: group, key: key) { [weak context] data in
+            context?.signWithNoiseKey(data)
+        }?.encode()
+    }
+
+    /// Sends the state payload to every connected roster member except us and
+    /// the excluded fingerprints. Offline members catch up the next time the
+    /// creator sends them state (v1 limitation, documented in the PR).
+    func distributeState(_ payload: Data, group: BitchatGroup, excluding excludedFingerprints: Set<String>, type: StateSendType) {
+        let myFingerprint = context.myNoiseFingerprint()
+        for member in group.members {
+            guard member.fingerprint != myFingerprint,
+                  !excludedFingerprints.contains(member.fingerprint),
+                  let peerID = context.connectedPeerID(forFingerprint: member.fingerprint) else { continue }
+            switch type {
+            case .invite:
+                context.sendGroupInvitePayload(payload, to: peerID)
+            case .keyUpdate:
+                context.sendGroupKeyUpdatePayload(payload, to: peerID)
+            }
+        }
+    }
+
+    /// Tells a just-removed member they're out so their client can deactivate
+    /// the group instead of silently going dark (dropping every message under
+    /// the epoch it no longer has the key for). The notice is a creator-signed
+    /// state whose roster excludes the removee — their `applyGroupState`
+    /// removal branch fires on the missing-self roster and surfaces the
+    /// "removed from group" system message.
+    ///
+    /// It carries a throwaway all-zero key, never the rotated key, so the
+    /// removee cannot decrypt post-removal traffic. State is sent 1:1 over
+    /// authenticated Noise, so no remaining member ever receives this blob
+    /// (and even if one did, its own missing-self check would not match).
+    /// If the removee is offline the notice can't be delivered — same v1
+    /// limitation as any other missed key update, documented in the PR.
+    func notifyRemovedMember(_ removed: GroupMember, rotated: BitchatGroup) {
+        guard let peerID = context.connectedPeerID(forFingerprint: removed.fingerprint) else { return }
+        let throwawayKey = Data(count: BitchatGroup.keyLength)
+        guard let payload = signedStatePayload(for: rotated, key: throwawayKey) else { return }
+        context.sendGroupKeyUpdatePayload(payload, to: peerID)
+    }
+
+    func applyGroupState(from peerID: PeerID, payload: Data, isInvite: Bool) {
+        guard let state = GroupStatePayload.decode(payload) else {
+            SecureLogger.warning("Malformed group state payload from \(peerID.id.prefix(8))…", category: .security)
+            return
+        }
+        // The Noise session already authenticated `peerID`; require that the
+        // authenticated peer IS the creator whose key signed the state, so a
+        // member can't re-invite or rotate on the creator's behalf.
+        guard let senderFingerprint = context.meshFingerprint(for: peerID),
+              senderFingerprint == state.creatorFingerprint else {
+            SecureLogger.warning("Dropping group state from non-creator \(peerID.id.prefix(8))…", category: .security)
+            return
+        }
+        guard state.verifyCreatorSignature() else {
+            SecureLogger.warning("Dropping group state with invalid creator signature", category: .security)
+            return
+        }
+
+        let myFingerprint = context.myNoiseFingerprint()
+        let existing = context.groupStore.group(withID: state.groupID)
+
+        // A creator-signed roster that no longer includes us is a removal.
+        guard state.members.contains(where: { $0.fingerprint == myFingerprint }) else {
+            if let existing {
+                if context.selectedPrivateChatPeer == existing.peerID {
+                    context.endPrivateChat()
+                }
+                context.removePrivateChat(existing.peerID)
+                context.groupStore.removeGroup(withID: existing.groupID)
+                context.addSystemMessage(String(
+                    format: String(localized: "system.group.removed_from", comment: "System message when removed from a group; placeholder is the group name"),
+                    locale: .current,
+                    existing.name
+                ))
+                context.notifyUIChanged()
+            }
+            return
+        }
+
+        // Never regress the epoch: state travels over live Noise sessions,
+        // so an older epoch here is a stale (or misbehaving) creator device.
+        if let existing, state.epoch < existing.epoch {
+            SecureLogger.warning("Dropping stale group state (epoch \(state.epoch) < \(existing.epoch))", category: .security)
+            return
+        }
+
+        let isNewMembership = existing == nil
+        guard context.groupStore.upsert(state.asGroup, key: state.key) else {
+            SecureLogger.error("Failed to store group state for \(state.name)", category: .session)
+            return
+        }
+
+        if isNewMembership {
+            let inviter = state.members.first { $0.fingerprint == state.creatorFingerprint }?.nickname
+                ?? context.peerNickname(for: peerID)
+                ?? "?"
+            let notice = String(
+                format: String(localized: "system.group.joined", comment: "System message when added to a group; placeholders are the group name and the inviter"),
+                locale: .current,
+                state.name,
+                inviter
+            )
+            context.addSystemMessage(notice)
+            context.markPrivateChatUnread(state.asGroup.peerID)
+            context.notifyPrivateMessage(from: inviter, message: notice, peerID: state.asGroup.peerID)
+        } else if isInvite == false, let existing, state.epoch > existing.epoch {
+            SecureLogger.info("Group '\(state.name)' rotated to epoch \(state.epoch)", category: .session)
+        }
+        context.notifyUIChanged()
+    }
+}

bitchat/ViewModels/ChatLifecycleCoordinator.swift

@@ -185,6 +185,13 @@ final class ChatLifecycleCoordinator {
     func markPrivateMessagesAsRead(from peerID: PeerID) {
         context.markChatAsRead(from: peerID)
 
+        // Group chats are keyed under a virtual group_ peerID; no member IS the
+        // conversation peer, so the receipt loops below (which gate on
+        // senderPeerID == peerID) must never emit a read/delivered receipt for
+        // one. This guard makes that explicit so a future refactor of the
+        // receipt matching can't silently start leaking receipts into groups.
+        guard !peerID.isGroup else { return }
+
         if peerID.isGeoDM,
            let recipientHex = context.nostrKeyMapping[peerID],
            case .location(let channel) = context.activeChannel,
@@ -324,7 +331,7 @@ private extension ChatLifecycleCoordinator {
 
             do {
                 let identity = try context.deriveNostrIdentity(forGeohash: channel.geohash)
-                let event = try NostrProtocol.createEphemeralGeohashEvent(
+                let event = try await NostrProtocol.createMinedEphemeralGeohashEvent(
                     content: message,
                     geohash: channel.geohash,
                     senderIdentity: identity,

bitchat/ViewModels/ChatOutgoingCoordinator.swift

@@ -68,10 +68,22 @@ extension ChatViewModel: ChatOutgoingContext {
 final class ChatOutgoingCoordinator {
     private unowned let context: any ChatOutgoingContext
 
+    /// In-flight NIP-13 mining for the most recent geohash send. A newer send
+    /// (or leaving the channel) cancels it, which only expedites the mining —
+    /// the message still goes out at the difficulty already reached.
+    /// (Read access is internal so tests can await the send's completion.)
+    private(set) var geohashMiningTask: Task<Void, Never>?
+
     init(context: any ChatOutgoingContext) {
         self.context = context
     }
 
+    /// Finish any in-flight geohash PoW mining early (the pending message
+    /// still sends, at whatever committed difficulty it reached).
+    func expeditePendingGeohashMining() {
+        geohashMiningTask?.cancel()
+    }
+
     func sendMessage(_ content: String) {
         guard let trimmed = content.trimmedOrNilIfEmpty else { return }
 
@@ -92,120 +104,117 @@ final class ChatOutgoingCoordinator {
         }
 
         let mentions = context.parseMentions(from: content)
-        let preparedMessage = preparePublicMessage(content: content, trimmed: trimmed, mentions: mentions)
-        guard let preparedMessage else { return }
 
-        appendLocalEcho(preparedMessage.message)
-        routePublicMessage(
-            originalContent: content,
-            mentions: mentions,
-            geoContext: preparedMessage.geoContext,
-            messageID: preparedMessage.message.id,
-            timestamp: preparedMessage.message.timestamp
-        )
+        switch context.activeChannel {
+        case .mesh:
+            sendMeshPublicMessage(originalContent: content, trimmed: trimmed, mentions: mentions)
+        case .location(let channel):
+            sendGeohashPublicMessage(trimmed, mentions: mentions, channel: channel)
+        }
     }
 }
 
 private extension ChatOutgoingCoordinator {
-    func preparePublicMessage(
-        content: String,
-        trimmed: String,
-        mentions: [String]
-    ) -> (message: BitchatMessage, geoContext: ChatViewModel.GeoOutgoingContext?)? {
-        var geoContext: ChatViewModel.GeoOutgoingContext?
-        var displaySender = context.nickname
-        var localSenderPeerID = context.myPeerID
-        var messageID: String?
-        var messageTimestamp = Date()
+    func sendMeshPublicMessage(originalContent: String, trimmed: String, mentions: [String]) {
+        let message = BitchatMessage(
+            sender: context.nickname,
+            content: trimmed,
+            timestamp: Date(),
+            isRelay: false,
+            senderPeerID: context.myPeerID,
+            mentions: mentions.isEmpty ? nil : mentions
+        )
 
-        switch context.activeChannel {
-        case .mesh:
-            break
+        appendLocalEcho(message, to: .mesh)
+        context.recordPublicActivity(forChannelKey: "mesh")
+        context.sendMeshMessage(
+            originalContent,
+            mentions: mentions,
+            messageID: message.id,
+            timestamp: message.timestamp
+        )
+    }
 
-        case .location(let channel):
+    /// Geohash sends mine a NIP-13 nonce tag first (off the main actor, see
+    /// `NostrPoW`), so the whole echo-and-send runs in a task once the signed
+    /// event — whose ID is also the local message ID — exists. Typical mining
+    /// at the default target is well under 100 ms and hard-capped at
+    /// `NostrPoW.miningTimeCap`, so sending is never meaningfully delayed.
+    func sendGeohashPublicMessage(_ trimmed: String, mentions: [String], channel: GeohashChannel) {
+        let identity: NostrIdentity
+        do {
+            identity = try context.deriveNostrIdentity(forGeohash: channel.geohash)
+        } catch {
+            SecureLogger.error("❌ Failed to prepare geohash message: \(error)", category: .session)
+            context.addSystemMessage(
+                String(localized: "system.location.send_failed", comment: "System message when a location channel send fails")
+            )
+            return
+        }
+
+        let displaySender = context.nickname + "#" + String(identity.publicKeyHex.suffix(4))
+        let senderPeerID = PeerID(nostr: identity.publicKeyHex)
+        let teleported = context.isTeleported
+        let nickname = context.nickname
+
+        // Serialize geohash sends: each send awaits the previous send's task
+        // before it appends + relays, so user-visible order always matches
+        // send order even when an earlier message mines longer than a later
+        // one. Cancelling the previous task only *expedites* its mining (the
+        // NIP-13 target is polled, not aborted), so it still finishes and
+        // sends — and it finishes fast, so awaiting it never stacks mining
+        // delays or blocks a send beyond `NostrPoW.miningTimeCap`.
+        let previousSend = geohashMiningTask
+        previousSend?.cancel()
+        geohashMiningTask = Task { @MainActor [weak context = self.context] in
+            await previousSend?.value
+
+            let event: NostrEvent
             do {
-                let identity = try context.deriveNostrIdentity(forGeohash: channel.geohash)
-                let suffix = String(identity.publicKeyHex.suffix(4))
-                displaySender = context.nickname + "#" + suffix
-                localSenderPeerID = PeerID(nostr: identity.publicKeyHex)
-
-                let teleported = context.isTeleported
-                let event = try NostrProtocol.createEphemeralGeohashEvent(
+                event = try await NostrProtocol.createMinedEphemeralGeohashEvent(
                     content: trimmed,
                     geohash: channel.geohash,
                     senderIdentity: identity,
-                    nickname: context.nickname,
-                    teleported: teleported
-                )
-
-                messageID = event.id
-                messageTimestamp = Date(timeIntervalSince1970: TimeInterval(event.created_at))
-                geoContext = (
-                    channel: channel,
-                    event: event,
-                    identity: identity,
+                    nickname: nickname,
                     teleported: teleported
                 )
             } catch {
                 SecureLogger.error("❌ Failed to prepare geohash message: \(error)", category: .session)
-                context.addSystemMessage(
-                    String(localized: "system.location.send_failed", comment: "System message when a location channel send fails")
-                )
-                return nil
-            }
-        }
-
-        let message = BitchatMessage(
-            id: messageID,
-            sender: displaySender,
-            content: trimmed,
-            timestamp: messageTimestamp,
-            isRelay: false,
-            senderPeerID: localSenderPeerID,
-            mentions: mentions.isEmpty ? nil : mentions
-        )
-
-        return (message, geoContext)
-    }
-
-    func appendLocalEcho(_ message: BitchatMessage) {
-        context.appendPublicMessage(message, to: ConversationID(channelID: context.activeChannel))
-
-        let contentKey = context.normalizedContentKey(message.content)
-        context.recordContentKey(contentKey, timestamp: message.timestamp)
-    }
-
-    func routePublicMessage(
-        originalContent: String,
-        mentions: [String],
-        geoContext: ChatViewModel.GeoOutgoingContext?,
-        messageID: String,
-        timestamp: Date
-    ) {
-        switch context.activeChannel {
-        case .mesh:
-            context.recordPublicActivity(forChannelKey: "mesh")
-            context.sendMeshMessage(
-                originalContent,
-                mentions: mentions,
-                messageID: messageID,
-                timestamp: timestamp
-            )
-
-        case .location(let channel):
-            context.recordPublicActivity(forChannelKey: "geo:\(channel.geohash)")
-
-            guard let geoContext, geoContext.channel.geohash == channel.geohash else {
-                SecureLogger.error("Geo: missing send context for \(channel.geohash)", category: .session)
-                context.addSystemMessage(
+                context?.addSystemMessage(
                     String(localized: "system.location.send_failed", comment: "System message when a location channel send fails")
                 )
                 return
             }
+            guard let context else { return }
 
-            Task { @MainActor [weak context = self.context] in
-                context?.sendGeohash(context: geoContext)
-            }
+            let message = BitchatMessage(
+                id: event.id,
+                sender: displaySender,
+                content: trimmed,
+                timestamp: Date(timeIntervalSince1970: TimeInterval(event.created_at)),
+                isRelay: false,
+                senderPeerID: senderPeerID,
+                mentions: mentions.isEmpty ? nil : mentions
+            )
+
+            context.appendPublicMessage(message, to: ConversationID(channelID: .location(channel)))
+            let contentKey = context.normalizedContentKey(message.content)
+            context.recordContentKey(contentKey, timestamp: message.timestamp)
+
+            context.recordPublicActivity(forChannelKey: "geo:\(channel.geohash)")
+            context.sendGeohash(context: (
+                channel: channel,
+                event: event,
+                identity: identity,
+                teleported: teleported
+            ))
         }
     }
+
+    func appendLocalEcho(_ message: BitchatMessage, to conversationID: ConversationID) {
+        context.appendPublicMessage(message, to: conversationID)
+
+        let contentKey = context.normalizedContentKey(message.content)
+        context.recordContentKey(contentKey, timestamp: message.timestamp)
+    }
 }

bitchat/ViewModels/ChatPeerIdentityCoordinator.swift

@@ -323,6 +323,15 @@ final class ChatPeerIdentityCoordinator {
     func startPrivateChat(with peerID: PeerID) {
         guard peerID != context.myPeerID else { return }
 
+        // Group chats are virtual conversations: no peer identity, favorites,
+        // handshake, or message consolidation applies — just select the chat.
+        if peerID.isGroup {
+            context.selectedPrivateChatFingerprint = nil
+            context.beginPrivateChatSession(with: peerID)
+            context.markPrivateChatRead(peerID)
+            return
+        }
+
         let peerNickname = context.peerNickname(for: peerID) ?? "unknown"
 
         if context.unifiedIsBlocked(peerID) {

bitchat/ViewModels/ChatPrivateConversationCoordinator.swift

@@ -227,10 +227,29 @@ extension ChatViewModel: ChatPrivateConversationContext {
 final class ChatPrivateConversationCoordinator {
     private unowned let context: any ChatPrivateConversationContext
 
+    // Outbox retries re-wrap the same message in fresh gift-wrap events, so
+    // relay-level event-ID dedup can't catch them; track inbound GeoDM
+    // message IDs so each copy past the first costs one (already-deduped)
+    // ack check and nothing else.
+    private var seenInboundGeoDMIDs: Set<String> = []
+    private var seenInboundGeoDMOrder: [String] = []
+    private static let seenInboundGeoDMCap = 512
+
     init(context: any ChatPrivateConversationContext) {
         self.context = context
     }
 
+    /// Returns `false` if this GeoDM message ID was already handled.
+    private func markInboundGeoDMSeen(_ messageId: String) -> Bool {
+        guard !seenInboundGeoDMIDs.contains(messageId) else { return false }
+        seenInboundGeoDMIDs.insert(messageId)
+        seenInboundGeoDMOrder.append(messageId)
+        if seenInboundGeoDMOrder.count > Self.seenInboundGeoDMCap {
+            seenInboundGeoDMIDs.remove(seenInboundGeoDMOrder.removeFirst())
+        }
+        return true
+    }
+
     func sendPrivateMessage(_ content: String, to peerID: PeerID) {
         guard !content.isEmpty else { return }
 
@@ -408,10 +427,15 @@ final class ChatPrivateConversationCoordinator {
         guard let pm = PrivateMessagePacket.decode(from: payload.data) else { return }
         let messageId = pm.messageID
 
-        SecureLogger.info("GeoDM: recv PM <- sender=\(senderPubkey.prefix(8))… mid=\(messageId.prefix(8))…", category: .session)
-
+        // Ack before the dedup guard: a re-sent copy means the sender may not
+        // have our DELIVERED yet, and markGeoDeliveryAckSent dedups the
+        // actual sends.
         sendDeliveryAckIfNeeded(to: messageId, senderPubKey: senderPubkey, from: id)
 
+        guard markInboundGeoDMSeen(messageId) else { return }
+
+        SecureLogger.info("GeoDM: recv PM <- sender=\(senderPubkey.prefix(8))… mid=\(messageId.prefix(8))…", category: .session)
+
         if context.isNostrBlocked(pubkeyHexLowercased: senderPubkey) {
             return
         }
@@ -490,7 +514,10 @@ final class ChatPrivateConversationCoordinator {
                 category: .session
             )
         } else {
-            SecureLogger.warning("GeoDM: delivered ack for unknown mid=\(messageID.prefix(8))… conv=\(convKey)", category: .session)
+            // A stale ack for a message this device no longer tracks (dropped
+            // outbox entry, cleared chat, or a peer re-acking after losing our
+            // receipt) — expected occasionally, not actionable.
+            SecureLogger.debug("GeoDM: delivered ack for unknown mid=\(messageID.prefix(8))… conv=\(convKey)", category: .session)
         }
     }
 

bitchat/ViewModels/ChatPublicConversationCoordinator.swift

@@ -82,7 +82,9 @@ protocol ChatPublicConversationContext: AnyObject {
     // MARK: Inbound public message processing
     func processActionMessage(_ message: BitchatMessage) -> BitchatMessage
     func isMessageBlocked(_ message: BitchatMessage) -> Bool
-    func allowPublicMessage(senderKey: String, contentKey: String) -> Bool
+    /// `powBits` is the validated NIP-13 difficulty of the source Nostr event
+    /// (0 for mesh messages); sufficient PoW relaxes the per-sender bucket.
+    func allowPublicMessage(senderKey: String, contentKey: String, powBits: Int) -> Bool
     /// Buffers a visible-channel message for the batched (~80 ms) pipeline
     /// flush, which commits it to `conversationID` in the store.
     func enqueuePublicMessage(_ message: BitchatMessage, to conversationID: ConversationID)
@@ -137,8 +139,8 @@ extension ChatViewModel: ChatPublicConversationContext {
         meshService.sendMessage(content, mentions: mentions, messageID: messageID, timestamp: timestamp)
     }
 
-    func allowPublicMessage(senderKey: String, contentKey: String) -> Bool {
-        publicRateLimiter.allow(senderKey: senderKey, contentKey: contentKey)
+    func allowPublicMessage(senderKey: String, contentKey: String, powBits: Int) -> Bool {
+        publicRateLimiter.allow(senderKey: senderKey, contentKey: contentKey, powBits: powBits)
     }
 
     func enqueuePublicMessage(_ message: BitchatMessage, to conversationID: ConversationID) {
@@ -290,7 +292,17 @@ final class ChatPublicConversationCoordinator: PublicMessagePipelineDelegate {
     func clearCurrentPublicTimeline() {
         context.clearPublicConversation(ConversationID(channelID: context.activeChannel))
 
+        // The SPM test process shares the real Application Support tree, so this
+        // detached deletion can land mid-test under parallel scheduling and flake
+        // a file-dependent test. Tests never need the on-disk media cleared.
+        guard !TestEnvironment.isRunningTests else { return }
+
         Task.detached(priority: .utility) {
+            // Skipped under tests: the test process shares the user's real
+            // ~/Library/Application Support/files tree, and this detached
+            // wipe fires at a nondeterministic time — racing tests that
+            // write media there (see the same guard in panicClearAllData).
+            guard !TestEnvironment.isRunningTests else { return }
             do {
                 let base = try FileManager.default.url(
                     for: .applicationSupportDirectory,
@@ -367,7 +379,7 @@ final class ChatPublicConversationCoordinator: PublicMessagePipelineDelegate {
                 guard let context else { return }
                 do {
                     let identity = try context.deriveNostrIdentity(forGeohash: channel.geohash)
-                    let event = try NostrProtocol.createEphemeralGeohashEvent(
+                    let event = try await NostrProtocol.createMinedEphemeralGeohashEvent(
                         content: content,
                         geohash: channel.geohash,
                         senderIdentity: identity,
@@ -395,7 +407,11 @@ final class ChatPublicConversationCoordinator: PublicMessagePipelineDelegate {
         )
     }
 
-    func handlePublicMessage(_ message: BitchatMessage) {
+    /// - Parameter powBits: validated NIP-13 difficulty of the source Nostr
+    ///   event (0 for mesh messages). Sufficient PoW relaxes the per-sender
+    ///   rate limit; low/no-PoW events keep the strict limits so old clients
+    ///   still get through at normal rates.
+    func handlePublicMessage(_ message: BitchatMessage, powBits: Int = 0) {
         let finalMessage = context.processActionMessage(message)
         if context.isMessageBlocked(finalMessage) { return }
 
@@ -405,7 +421,7 @@ final class ChatPublicConversationCoordinator: PublicMessagePipelineDelegate {
         if shouldRateLimit {
             let senderKey = normalizedSenderKey(for: finalMessage)
             let contentKey = context.normalizedContentKey(finalMessage.content)
-            if !context.allowPublicMessage(senderKey: senderKey, contentKey: contentKey) {
+            if !context.allowPublicMessage(senderKey: senderKey, contentKey: contentKey, powBits: powBits) {
                 return
             }
         }

bitchat/ViewModels/ChatTransportEventCoordinator.swift

@@ -71,6 +71,11 @@ protocol ChatTransportEventContext: AnyObject {
     // MARK: Verification payloads
     func handleVerifyChallengePayload(from peerID: PeerID, payload: Data)
     func handleVerifyResponsePayload(from peerID: PeerID, payload: Data)
+
+    // MARK: Group payloads (creator-signed state over Noise)
+    func handleGroupInvitePayload(from peerID: PeerID, payload: Data)
+    func handleGroupKeyUpdatePayload(from peerID: PeerID, payload: Data)
+    func handleVouchPayload(from peerID: PeerID, payload: Data)
 }
 
 extension ChatViewModel: ChatTransportEventContext {
@@ -129,6 +134,18 @@ extension ChatViewModel: ChatTransportEventContext {
     func handleVerifyResponsePayload(from peerID: PeerID, payload: Data) {
         verificationCoordinator.handleVerifyResponsePayload(from: peerID, payload: payload)
     }
+
+    func handleGroupInvitePayload(from peerID: PeerID, payload: Data) {
+        groupCoordinator.handleGroupInvitePayload(from: peerID, payload: payload)
+    }
+
+    func handleGroupKeyUpdatePayload(from peerID: PeerID, payload: Data) {
+        groupCoordinator.handleGroupKeyUpdatePayload(from: peerID, payload: payload)
+    }
+
+    func handleVouchPayload(from peerID: PeerID, payload: Data) {
+        vouchCoordinator.handleVouchPayload(from: peerID, payload: payload)
+    }
 }
 
 final class ChatTransportEventCoordinator {
@@ -371,6 +388,15 @@ private extension ChatTransportEventCoordinator {
 
         case .verifyResponse:
             context.handleVerifyResponsePayload(from: peerID, payload: payload)
+
+        case .groupInvite:
+            context.handleGroupInvitePayload(from: peerID, payload: payload)
+
+        case .groupKeyUpdate:
+            context.handleGroupKeyUpdatePayload(from: peerID, payload: payload)
+
+        case .vouch:
+            context.handleVouchPayload(from: peerID, payload: payload)
         }
     }
 

bitchat/ViewModels/ChatVerificationCoordinator.swift

@@ -24,6 +24,10 @@ protocol ChatVerificationContext: AnyObject {
     func setStoredVerified(_ fingerprint: String, verified: Bool)
     func isVerifiedFingerprint(_ fingerprint: String) -> Bool
     func saveIdentityState()
+    /// After a fingerprint becomes verified, run a transitive-vouch pass over
+    /// currently connected peers (so verifying a peer you're already connected
+    /// to sends vouches immediately, and the new identity propagates onward).
+    func vouchToConnectedVerifiedPeers()
 
     // MARK: Encryption status
     func setEncryptionStatus(_ status: EncryptionStatus?, for peerID: PeerID)
@@ -86,6 +90,10 @@ extension ChatViewModel: ChatVerificationContext {
         peerIdentityStore.setVerified(fingerprint, verified: verified)
     }
 
+    func vouchToConnectedVerifiedPeers() {
+        vouchCoordinator.vouchToConnectedVerifiedPeers()
+    }
+
     var unifiedPeers: [BitchatPeer] {
         unifiedPeerService.peers
     }
@@ -148,6 +156,9 @@ final class ChatVerificationCoordinator {
         context.saveIdentityState()
         context.setStoredVerified(fingerprint, verified: true)
         context.updateEncryptionStatus(for: peerID)
+        // Verifying a peer is a vouch trigger: push attestations to my other
+        // connected verified peers (and to this one if already connected).
+        context.vouchToConnectedVerifiedPeers()
     }
 
     func unverifyFingerprint(for peerID: PeerID) {
@@ -340,6 +351,8 @@ final class ChatVerificationCoordinator {
         }
 
         context.updateEncryptionStatus(for: peerID)
+        // QR verification just completed — same vouch trigger as manual verify.
+        context.vouchToConnectedVerifiedPeers()
     }
 }
 

bitchat/ViewModels/ChatViewModel.swift

@@ -102,7 +102,9 @@ final class ChatViewModel: ObservableObject, BitchatDelegate, TransportEventDele
     @MainActor
     var canSendMediaInCurrentContext: Bool {
         if let peer = selectedPrivateChatPeer {
-            return !(peer.isGeoDM || peer.isGeoChat)
+            // Media transfer is not wired for groups in v1 (sendFilePrivate
+            // rejects the virtual group_ recipient), so keep the affordance off.
+            return !(peer.isGeoDM || peer.isGeoChat || peer.isGroup)
         }
         switch activeChannel {
         case .mesh: return true
@@ -177,6 +179,8 @@ final class ChatViewModel: ObservableObject, BitchatDelegate, TransportEventDele
     lazy var nostrCoordinator = ChatNostrCoordinator(context: self)
     lazy var mediaTransferCoordinator = ChatMediaTransferCoordinator(context: self)
     lazy var verificationCoordinator = ChatVerificationCoordinator(context: self)
+    lazy var groupCoordinator = ChatGroupCoordinator(context: self)
+    lazy var vouchCoordinator = ChatVouchCoordinator(context: self)
 
     // Computed properties for compatibility
     @MainActor
@@ -305,12 +309,17 @@ final class ChatViewModel: ObservableObject, BitchatDelegate, TransportEventDele
     var nostrRelayManager: NostrRelayManager?
     private let userDefaults = UserDefaults.standard
     let keychain: KeychainManagerProtocol
+    /// Private group membership: keys in the keychain, metadata on disk.
+    let groupStore: GroupStore
     private let nicknameKey = "bitchat.nickname"
     // Location channel state (macOS supports manual geohash selection)
     var activeChannel: ChannelID {
         get { conversations.activeChannel }
         set {
             guard conversations.activeChannel != newValue else { return }
+            // Leaving a channel expedites any in-flight NIP-13 mining: the
+            // pending message still sends, at the difficulty already reached.
+            outgoingCoordinator.expeditePendingGeohashMining()
             conversations.setActiveChannel(newValue)
             visibleMessagesCache = nil
             objectWillChange.send()
@@ -809,6 +818,7 @@ final class ChatViewModel: ObservableObject, BitchatDelegate, TransportEventDele
         )
 
         self.keychain = keychain
+        self.groupStore = GroupStore(keychain: keychain)
         self.idBridge = idBridge
         self.identityManager = identityManager
         self.conversations = conversations
@@ -1205,6 +1215,16 @@ final class ChatViewModel: ObservableObject, BitchatDelegate, TransportEventDele
         GossipMessageArchive.wipeDefault()
         StoreAndForwardMetrics.shared.reset()
 
+        // Drop private group keys and rosters (keychain + disk)
+        groupStore.wipe()
+        // Drop cached peers' prekey bundles (who we could write to is
+        // metadata too). Our own prekey privates are keychain-backed and go
+        // with deleteAllKeychainData above plus the identity reset below.
+        PrekeyBundleStore.shared.wipe()
+        // Drop bulletin-board posts and tombstones (memory and disk); board
+        // posts are signed with our identity key and persist for days.
+        BoardStore.shared.wipe()
+
         // Identity manager has cleared persisted identity data above
 
         // Clear autocomplete state
@@ -1273,6 +1293,13 @@ final class ChatViewModel: ObservableObject, BitchatDelegate, TransportEventDele
 
         // Delete ALL media files (incoming and outgoing) in background
         Task.detached(priority: .utility) {
+            // Skipped under tests: the test process shares the user's real
+            // ~/Library/Application Support/files tree, and this detached
+            // utility-priority wipe fires at a nondeterministic time —
+            // deleting media that concurrently running tests (e.g. the
+            // sendImage flow) just wrote there, and the developer's real
+            // app data with it.
+            guard !TestEnvironment.isRunningTests else { return }
             do {
                 let base = try FileManager.default.url(for: .applicationSupportDirectory, in: .userDomainMask, appropriateFor: nil, create: true)
                 let filesDir = base.appendingPathComponent("files", isDirectory: true)
@@ -1485,6 +1512,14 @@ final class ChatViewModel: ObservableObject, BitchatDelegate, TransportEventDele
 
     func setupNoiseCallbacks() {
         verificationCoordinator.setupNoiseCallbacks()
+        vouchCoordinator.setupNoiseCallbacks()
+    }
+
+    /// Whether the fingerprint currently counts as vouched (≥1 valid vouch
+    /// from a voucher I verified, and no explicit verification of mine).
+    @MainActor
+    func isVouchedFingerprint(_ fingerprint: String) -> Bool {
+        identityManager.isVouched(fingerprint: fingerprint)
     }
 
     // MARK: - BitchatDelegate Methods
@@ -1524,6 +1559,33 @@ final class ChatViewModel: ObservableObject, BitchatDelegate, TransportEventDele
         }
     }
 
+    /// Origin conversation for deferred command output, captured when the
+    /// command is issued (before any async work starts).
+    @MainActor
+    func currentCommandDestination() -> CommandOutputDestination {
+        if let peerID = selectedPrivateChatPeer {
+            return .privateChat(peerID)
+        }
+        // Deferring commands (/ping) are rejected in geohash channels, so a
+        // non-DM origin is always the #mesh timeline.
+        return .meshTimeline
+    }
+
+    /// Routes deferred command output (async /ping results) into the
+    /// conversation captured at issue time, immune to chat switches in the
+    /// meantime. A DM result lands in the origin chat's history even if that
+    /// chat is no longer selected (or was cleared — it then reappears as the
+    /// first message when the chat is reopened).
+    @MainActor
+    func addCommandOutput(_ content: String, to destination: CommandOutputDestination) {
+        switch destination {
+        case .privateChat(let peerID):
+            addLocalPrivateSystemMessage(content, to: peerID)
+        case .meshTimeline:
+            publicConversationCoordinator.addMeshOnlySystemMessage(content)
+        }
+    }
+
     // MARK: - Message Reception
 
     @MainActor
@@ -1555,6 +1617,12 @@ final class ChatViewModel: ObservableObject, BitchatDelegate, TransportEventDele
         )
     }
 
+    func didReceiveGroupMessage(payload: Data, timestamp: Date) {
+        Task { @MainActor [weak self] in
+            self?.groupCoordinator.handleGroupMessagePayload(payload, timestamp: timestamp)
+        }
+    }
+
     // MARK: - QR Verification API
     @MainActor
     func beginQRVerification(with qr: VerificationService.VerificationQR) -> Bool {
@@ -1582,6 +1650,12 @@ final class ChatViewModel: ObservableObject, BitchatDelegate, TransportEventDele
 
     func didUpdatePeerList(_ peers: [PeerID]) {
         peerListCoordinator.didUpdatePeerList(peers)
+        // A peer-list update follows every verified announce, which is where a
+        // peer's `.vouch` capability actually arrives — retry vouching now that
+        // capabilities may finally be known (closes the auth-time capability race).
+        Task { @MainActor [weak self] in
+            self?.vouchCoordinator.peersUpdated(peers)
+        }
     }
 
     @MainActor
@@ -1670,6 +1744,19 @@ final class ChatViewModel: ObservableObject, BitchatDelegate, TransportEventDele
     func addGeohashOnlySystemMessage(_ content: String) {
         publicConversationCoordinator.addGeohashOnlySystemMessage(content)
     }
+
+    /// Add a local system message to one specific geohash timeline, active or
+    /// not. Used by the board's new-pin alerts to scope-match the pin's channel.
+    @MainActor
+    func addGeohashSystemMessage(_ content: String, geohash: String) {
+        let systemMessage = BitchatMessage(
+            sender: "system",
+            content: content,
+            timestamp: Date(),
+            isRelay: false
+        )
+        appendGeohashMessageIfAbsent(systemMessage, toGeohash: geohash)
+    }
     // Send a public message without adding a local user echo.
     // Used for emotes where we want a local system-style confirmation instead.
     @MainActor
@@ -1677,12 +1764,27 @@ final class ChatViewModel: ObservableObject, BitchatDelegate, TransportEventDele
         publicConversationCoordinator.sendPublicRaw(content)
     }
 
+    // Send a normal public message (with local echo) to the active channel.
+    // CommandContextProvider hook for commands that post real messages
+    // (`/pay`); only called when no private chat is selected.
+    @MainActor
+    func sendPublicMessage(_ content: String) {
+        sendMessage(content)
+    }
+
     /// Handle incoming public message
     @MainActor
     func handlePublicMessage(_ message: BitchatMessage) {
         publicConversationCoordinator.handlePublicMessage(message)
     }
 
+    /// Handle an incoming public Nostr message with its validated NIP-13
+    /// difficulty; sufficient PoW relaxes the per-sender rate limit.
+    @MainActor
+    func handlePublicMessage(_ message: BitchatMessage, powBits: Int) {
+        publicConversationCoordinator.handlePublicMessage(message, powBits: powBits)
+    }
+
     /// Check for mentions and send notifications
     func checkForMentions(_ message: BitchatMessage) {
         publicConversationCoordinator.checkForMentions(message)

bitchat/ViewModels/ChatViewModelBootstrapper.swift

@@ -41,7 +41,11 @@ struct ChatViewModelServiceBundle {
         self.privateChatManager = privateChatManager
         self.unifiedPeerService = unifiedPeerService
         self.autocompleteService = AutocompleteService()
-        self.deduplicationService = MessageDeduplicationService()
+        // Persist processed gift-wrap event IDs: NIP-59 randomizes their
+        // timestamps, so the 24h-lookback DM subscriptions redeliver the same
+        // events on every launch and only a cross-launch record stops the
+        // reprocessing (re-sent DELIVERED bursts, phantom-ack noise).
+        self.deduplicationService = MessageDeduplicationService(nostrEventStore: NostrProcessedEventStore())
         self.publicMessagePipeline = PublicMessagePipeline()
     }
 }
@@ -72,6 +76,7 @@ final class ChatViewModelBootstrapper {
         configureNoiseCallbacks()
         bindTransferProgress()
         configureGeoChannels()
+        configureGateway()
         bindTeleportState()
         requestNotifications()
         registerObservers()
@@ -244,6 +249,72 @@ private extension ChatViewModelBootstrapper {
         )
     }
 
+    /// Wires the gateway-mode policy layer (`GatewayService`) to the mesh
+    /// transport, the relay manager, and the inbound Nostr pipeline. All
+    /// dependencies are closures so the service stays unit-testable with
+    /// fakes.
+    func configureGateway() {
+        // Gateway mode bridges BLE mesh <-> Nostr; a mock transport (tests)
+        // has no carrier packets to bridge.
+        guard let bleService = viewModel.meshService as? BLEService else { return }
+        let gateway = GatewayService.shared
+
+        gateway.publishToRelays = { event, geohash in
+            let relays = GeoRelayDirectory.shared.closestRelays(
+                toGeohash: geohash,
+                count: TransportConfig.nostrGeoRelayCount
+            )
+            // Symmetric with the local send path (GeohashSubscriptionManager
+            // .sendGeohash): with no known geo relay, refuse rather than
+            // publish to default relays no geo subscriber reads — that would
+            // be silent dead traffic, not delivery.
+            guard !relays.isEmpty else {
+                SecureLogger.warning("🌐 Gateway: no geo relays for #\(geohash); not publishing carried event", category: .session)
+                return
+            }
+            NostrRelayManager.shared.sendEvent(event, to: relays)
+        }
+        gateway.broadcastToMesh = { [weak bleService] payload in
+            bleService?.broadcastNostrCarrier(payload)
+        }
+        gateway.sendToGatewayPeer = { [weak bleService] payload, peer in
+            bleService?.sendNostrCarrier(payload, to: peer) ?? false
+        }
+        gateway.availableGatewayPeers = { [weak bleService] in
+            bleService?.reachableGatewayPeers() ?? []
+        }
+        gateway.relaysConnected = { NostrRelayManager.shared.isConnected }
+        gateway.currentGeohash = { [weak viewModel] in viewModel?.currentGeohash }
+        // Carried events enter the same pipeline as relay-received events so
+        // blocking, rate limits, dedup, and rendering behave identically.
+        gateway.injectInbound = { [weak viewModel] event in
+            viewModel?.handleNostrEvent(event)
+        }
+        // The capability bit is advertised ONLY while the toggle is on; a
+        // change forces a re-announce so peers learn promptly.
+        gateway.onEnabledChanged = { [weak bleService] enabled in
+            bleService?.setLocalCapability(.gateway, enabled: enabled)
+        }
+        bleService.onNostrCarrierPacket = { payload, from, directedToUs in
+            GatewayService.shared.handleMeshCarrier(payload, from: from, directedToUs: directedToUs)
+        }
+
+        // Uplinks deposited while relays were unreachable flush on reconnect.
+        NostrRelayManager.shared.$isConnected
+            .receive(on: DispatchQueue.main)
+            .sink { connected in
+                if connected {
+                    GatewayService.shared.flushQueuedUplinks()
+                }
+            }
+            .store(in: &viewModel.cancellables)
+
+        // Apply the persisted toggle at launch.
+        if gateway.isEnabled {
+            bleService.setLocalCapability(.gateway, enabled: true)
+        }
+    }
+
     func bindTeleportState() {
         viewModel.locationManager.$teleported
             .receive(on: DispatchQueue.main)

bitchat/ViewModels/ChatVouchCoordinator.swift

@@ -0,0 +1,272 @@
+import BitFoundation
+import BitLogger
+import Foundation
+
+/// The narrow surface `ChatVouchCoordinator` needs from its owner.
+///
+/// Follows the `ChatDeliveryContext` exemplar: the coordinator depends on the
+/// minimal context it actually uses instead of holding an `unowned` back-ref
+/// to the whole `ChatViewModel`. This keeps the coordinator independently
+/// testable (see `ChatVouchCoordinatorContextTests`) and makes its true
+/// dependencies explicit.
+@MainActor
+protocol ChatVouchContext: AnyObject {
+    // MARK: Identity & trust state
+    func getFingerprint(for peerID: PeerID) -> String?
+    func isVerifiedFingerprint(_ fingerprint: String) -> Bool
+    /// The peer's announce-bound Ed25519 signing key, if known this session.
+    func signingKey(forFingerprint fingerprint: String) -> Data?
+    /// Verified fingerprints ordered most recently verified first.
+    func recentlyVerifiedFingerprints(limit: Int, excluding fingerprint: String) -> [String]
+    /// Stores an accepted vouch (identity manager enforces the storage gates).
+    @discardableResult
+    func recordVouch(voucheeFingerprint: String, voucherFingerprint: String, timestamp: Date) -> Bool
+    func lastVouchBatchSent(to fingerprint: String) -> Date?
+    func markVouchBatchSent(to fingerprint: String, at date: Date)
+
+    // MARK: Transport
+    func peerCapabilities(for peerID: PeerID) -> PeerCapabilities
+    /// PeerIDs with a currently established mesh session (used to run a vouch
+    /// pass over peers we are already connected to when we verify someone).
+    func connectedPeerIDs() -> [PeerID]
+    /// Appends a session-established observer (additive; never displaces the
+    /// verification coordinator's callbacks).
+    func addPeerAuthenticatedObserver(_ handler: @escaping (PeerID, String) -> Void)
+    /// Signs `data` with our Noise (Ed25519) signing key.
+    func noiseSignData(_ data: Data) -> Data?
+    func sendVouchAttestations(_ payload: Data, to peerID: PeerID)
+
+    // MARK: UI refresh
+    /// Signals that derived trust state changed so peer list / fingerprint
+    /// views recompute badges.
+    func notifyPeerTrustChanged()
+}
+
+extension ChatViewModel: ChatVouchContext {
+    // `getFingerprint(for:)` and `isVerifiedFingerprint(_:)` are shared
+    // requirements with the verification context and satisfied by existing
+    // `ChatViewModel` members. The members below flatten nested service
+    // accesses into intent-named calls.
+
+    func signingKey(forFingerprint fingerprint: String) -> Data? {
+        identityManager.signingPublicKey(forFingerprint: fingerprint)
+    }
+
+    func recentlyVerifiedFingerprints(limit: Int, excluding fingerprint: String) -> [String] {
+        identityManager.mostRecentlyVerifiedFingerprints(limit: limit, excluding: fingerprint)
+    }
+
+    @discardableResult
+    func recordVouch(voucheeFingerprint: String, voucherFingerprint: String, timestamp: Date) -> Bool {
+        identityManager.recordVouch(
+            voucheeFingerprint: voucheeFingerprint,
+            voucherFingerprint: voucherFingerprint,
+            timestamp: timestamp
+        )
+    }
+
+    func lastVouchBatchSent(to fingerprint: String) -> Date? {
+        identityManager.lastVouchBatchSent(to: fingerprint)
+    }
+
+    func markVouchBatchSent(to fingerprint: String, at date: Date) {
+        identityManager.markVouchBatchSent(to: fingerprint, at: date)
+    }
+
+    func peerCapabilities(for peerID: PeerID) -> PeerCapabilities {
+        meshService.peerCapabilities(peerID)
+    }
+
+    func connectedPeerIDs() -> [PeerID] {
+        Array(connectedPeers)
+    }
+
+    func addPeerAuthenticatedObserver(_ handler: @escaping (PeerID, String) -> Void) {
+        meshService.addPeerAuthenticatedObserver(handler)
+    }
+
+    func noiseSignData(_ data: Data) -> Data? {
+        meshService.noiseSignData(data)
+    }
+
+    func sendVouchAttestations(_ payload: Data, to peerID: PeerID) {
+        meshService.sendVouchAttestations(payload, to: peerID)
+    }
+
+    func notifyPeerTrustChanged() {
+        // PeerListModel refreshes on this notification; the view-model change
+        // covers FingerprintView / VerificationModel consumers.
+        NotificationCenter.default.post(name: Notification.Name("peerStatusUpdated"), object: nil)
+        notifyUIChanged()
+    }
+}
+
+/// Transitive verification ("vouching"): when a Noise session comes up with a
+/// peer I verified, I attest — over that authenticated, encrypted session —
+/// to the other identities I have verified. Receivers accept such vouches
+/// only from peers *they* verified, giving a serverless
+/// verified-by-people-you-verified tier (`TrustLevel.vouched`).
+@MainActor
+final class ChatVouchCoordinator {
+    /// Minimum spacing between vouch batches to the same peer (persisted).
+    static let batchInterval: TimeInterval = 24 * 60 * 60
+
+    private unowned let context: any ChatVouchContext
+
+    init(context: any ChatVouchContext) {
+        self.context = context
+    }
+
+    /// Registers the session-established hook. Additive alongside the
+    /// verification coordinator's callbacks; call once at bootstrap.
+    func setupNoiseCallbacks() {
+        context.addPeerAuthenticatedObserver { [weak self] peerID, fingerprint in
+            DispatchQueue.main.async { [weak self] in
+                self?.peerAuthenticated(peerID, fingerprint: fingerprint)
+            }
+        }
+    }
+
+    /// Trigger — session established: on a Noise session coming up with a peer
+    /// I verified, attempt to send a vouch batch. Kept as the historical entry
+    /// point; the real work lives in `attemptVouch`.
+    func peerAuthenticated(_ peerID: PeerID, fingerprint: String, now: Date = Date()) {
+        attemptVouch(to: peerID, fingerprint: fingerprint, now: now)
+    }
+
+    /// Trigger — verified announce processed: a peer's `.vouch` capability
+    /// arrives on its *announce*, which is handled independently of the Noise
+    /// handshake. This is invoked on every peer-list update (fired after each
+    /// verified announce), so it closes the capability race — the batch that
+    /// `peerAuthenticated` couldn't send (capabilities not yet known) goes out
+    /// once the capability-bearing announce lands. Throttled per peer.
+    func peersUpdated(_ peerIDs: [PeerID], now: Date = Date()) {
+        for peerID in peerIDs {
+            guard let fingerprint = context.getFingerprint(for: peerID) else { continue }
+            attemptVouch(to: peerID, fingerprint: fingerprint, now: now)
+        }
+    }
+
+    /// Trigger — local verification completed: the user just verified a peer.
+    /// Run a vouch pass over every currently connected peer I verified. This
+    /// makes vouching fire when verifying someone already connected (whose
+    /// session is authenticated, so `peerAuthenticated` never re-fires), and it
+    /// propagates the newly-verified identity to my other verified peers.
+    /// Throttled per peer by `batchInterval`, so it can't spam.
+    func vouchToConnectedVerifiedPeers(now: Date = Date()) {
+        var sentCount = 0
+        for peerID in context.connectedPeerIDs() {
+            guard let fingerprint = context.getFingerprint(for: peerID) else { continue }
+            if attemptVouch(to: peerID, fingerprint: fingerprint, now: now) {
+                sentCount += 1
+            }
+        }
+        if sentCount > 0 {
+            SecureLogger.info(
+                "🪪 verify-triggered vouch pass sent to \(sentCount) connected peer(s)",
+                category: .security
+            )
+        }
+    }
+
+    /// Exchange policy shared by every trigger: to a peer I verified, send
+    /// attestations for up to `VouchAttestation.maxBatchCount` *other* verified
+    /// fingerprints (most recently verified first), at most once per peer per
+    /// `batchInterval`. Returns whether a batch was actually sent.
+    @discardableResult
+    func attemptVouch(to peerID: PeerID, fingerprint: String, now: Date = Date()) -> Bool {
+        guard context.isVerifiedFingerprint(fingerprint) else { return false }
+
+        // Capability gate, race-tolerant: a peer's `.vouch` bit is carried on
+        // its announce, processed independently of the Noise handshake, so at
+        // authentication time the capability set is frequently still empty.
+        // Treat an empty/unknown set as eligible — the payload is a Noise
+        // `0x12` (`NoisePayloadType.vouch`) that non-supporting peers harmlessly
+        // ignore, so sending on an unknown set is safe and avoids the race
+        // dropping the batch. Only skip when the peer advertised a non-empty
+        // capability set that explicitly lacks `.vouch`.
+        let capabilities = context.peerCapabilities(for: peerID)
+        if !capabilities.isEmpty, !capabilities.contains(.vouch) { return false }
+
+        if let lastSent = context.lastVouchBatchSent(to: fingerprint),
+           now.timeIntervalSince(lastSent) < Self.batchInterval {
+            return false
+        }
+
+        let candidates = context.recentlyVerifiedFingerprints(
+            limit: VouchAttestation.maxBatchCount,
+            excluding: fingerprint
+        )
+        var attestations: [VouchAttestation] = []
+        for candidate in candidates {
+            // Only fingerprints whose announce-bound signing key we know can
+            // be anchored to a concrete identity; skip the rest.
+            guard let fingerprintData = Data(hexString: candidate),
+                  fingerprintData.count == VouchAttestation.fingerprintSize,
+                  let signingKey = context.signingKey(forFingerprint: candidate),
+                  signingKey.count == VouchAttestation.signingKeySize,
+                  let attestation = VouchAttestation.build(
+                      voucheeFingerprint: fingerprintData,
+                      voucheeSigningKey: signingKey,
+                      timestampMs: UInt64(now.timeIntervalSince1970 * 1000),
+                      sign: context.noiseSignData
+                  ) else {
+                continue
+            }
+            attestations.append(attestation)
+        }
+
+        guard !attestations.isEmpty,
+              let payload = VouchAttestation.encodeList(attestations) else { return false }
+        context.sendVouchAttestations(payload, to: peerID)
+        context.markVouchBatchSent(to: fingerprint, at: now)
+        SecureLogger.debug(
+            "🪪 Sent \(attestations.count) vouch attestation(s) to \(peerID.id.prefix(8))…",
+            category: .security
+        )
+        return true
+    }
+
+    /// Accept policy: process inbound vouches only from a sender I verified,
+    /// only with a valid Ed25519 signature under the sender's announce-bound
+    /// signing key, and only within the validity window. Self-vouches and
+    /// vouches for already-verified peers are dropped by the identity
+    /// manager's storage gates.
+    func handleVouchPayload(from peerID: PeerID, payload: Data, now: Date = Date()) {
+        guard let senderFingerprint = context.getFingerprint(for: peerID),
+              context.isVerifiedFingerprint(senderFingerprint) else {
+            SecureLogger.debug(
+                "🪪 Ignoring vouch payload from unverified peer \(peerID.id.prefix(8))…",
+                category: .security
+            )
+            return
+        }
+        guard let senderSigningKey = context.signingKey(forFingerprint: senderFingerprint) else {
+            SecureLogger.debug(
+                "🪪 No signing key for vouching peer \(peerID.id.prefix(8))…; dropping batch",
+                category: .security
+            )
+            return
+        }
+
+        var acceptedCount = 0
+        for attestation in VouchAttestation.decodeList(from: payload) {
+            guard attestation.verifySignature(voucherSigningKey: senderSigningKey),
+                  !attestation.isExpired(now: now) else { continue }
+            let stored = context.recordVouch(
+                voucheeFingerprint: attestation.voucheeFingerprintHex,
+                voucherFingerprint: senderFingerprint,
+                timestamp: attestation.timestamp
+            )
+            if stored { acceptedCount += 1 }
+        }
+
+        if acceptedCount > 0 {
+            SecureLogger.info(
+                "🪪 Accepted \(acceptedCount) vouch(es) from \(senderFingerprint.prefix(8))…",
+                category: .security
+            )
+            context.notifyPeerTrustChanged()
+        }
+    }
+}

bitchat/ViewModels/Extensions/ChatViewModel+PrivateChat.swift

@@ -13,6 +13,12 @@ extension ChatViewModel {
 
     @MainActor
     func sendPrivateMessage(_ content: String, to peerID: PeerID) {
+        // Group chats reuse the private-chat surface but broadcast a sealed
+        // envelope instead of routing to a single peer.
+        if peerID.isGroup {
+            groupCoordinator.sendGroupMessage(content, to: peerID)
+            return
+        }
         privateConversationCoordinator.sendPrivateMessage(content, to: peerID)
     }
 

bitchat/ViewModels/GeohashSubscriptionManager.swift

@@ -115,6 +115,9 @@ final class GeohashSubscriptionManager {
     private weak var context: (any GeohashSubscriptionContext)?
     private let inbound: NostrInboundPipeline
     private let presence: GeoPresenceTracker
+    /// Geohashes already told "sent via mesh gateway" this session, so the
+    /// notice appears once per channel instead of once per message.
+    private var gatewayNoticeGeohashes = Set<String>()
 
     init(context: any GeohashSubscriptionContext, inbound: NostrInboundPipeline, presence: GeoPresenceTracker) {
         self.context = context
@@ -145,6 +148,9 @@ final class GeohashSubscriptionManager {
         NostrRelayManager.shared.subscribe(filter: filter, id: subID, relayUrls: subRelays) { [weak self] event in
             Task { @MainActor [weak self] in
                 self?.inbound.subscribeNostrEvent(event)
+                // Gateway downlink: rebroadcast relay events for the viewed
+                // channel onto the mesh (no-op unless gateway mode is on).
+                GatewayService.shared.rebroadcastRelayEvent(event, geohash: channel.geohash)
             }
         }
 
@@ -235,6 +241,9 @@ final class GeohashSubscriptionManager {
         NostrRelayManager.shared.subscribe(filter: filter, id: subID, relayUrls: subRelays) { [weak self] event in
             Task { @MainActor [weak self] in
                 self?.inbound.handleNostrEvent(event)
+                // Gateway downlink: rebroadcast relay events for the viewed
+                // channel onto the mesh (no-op unless gateway mode is on).
+                GatewayService.shared.rebroadcastRelayEvent(event, geohash: channel.geohash)
             }
         }
 
@@ -280,6 +289,23 @@ final class GeohashSubscriptionManager {
             NostrRelayManager.shared.sendEvent(event, to: targetRelays)
         }
 
+        // Mesh gateway uplink: with no working relay connection, hand the
+        // locally signed event to a mesh peer advertising the gateway
+        // capability (keys never leave this device — only the finished,
+        // signed event travels). Uplink is only ever attempted here, for a
+        // freshly composed event, never for received carrier events (loop
+        // rule 3 in GatewayService).
+        if GatewayService.shared.uplinkViaMesh(event: event, geohash: channel.geohash),
+           gatewayNoticeGeohashes.insert(channel.geohash).inserted {
+            context.addPublicSystemMessage(
+                String(
+                    localized: "system.gateway.sent_via_mesh",
+                    defaultValue: "sent via mesh gateway",
+                    comment: "System message when a geohash message was handed to a mesh internet gateway because no relay is reachable"
+                )
+            )
+        }
+
         context.recordGeoParticipant(pubkeyHex: identity.publicKeyHex)
         context.registerNostrKeyMapping(identity.publicKeyHex, for: PeerID(nostr: identity.publicKeyHex))
         SecureLogger.debug(

bitchat/ViewModels/MessageRateLimiter.swift

@@ -48,15 +48,25 @@ struct MessageRateLimiter {
         self.contentRefill = contentRefillPerSec
     }
 
-    mutating func allow(senderKey: String, contentKey: String, now: Date = Date()) -> Bool {
-        var senderBucket = senderBuckets[senderKey] ?? TokenBucket(
-            capacity: senderCapacity,
-            tokens: senderCapacity,
-            refillPerSec: senderRefill,
-            lastRefill: now
-        )
-        let senderAllowed = senderBucket.allow(now: now)
-        senderBuckets[senderKey] = senderBucket
+    /// - Parameter powBits: validated NIP-13 difficulty of the event
+    ///   (`NostrPoW.validatedDifficulty`; 0 for mesh or no-PoW events).
+    ///   At or above `NostrPoW.rateLimitBypassBits` the per-sender bucket is
+    ///   skipped entirely — each such message paid for itself with work — but
+    ///   the per-content flood bucket still applies.
+    mutating func allow(senderKey: String, contentKey: String, powBits: Int = 0, now: Date = Date()) -> Bool {
+        let senderAllowed: Bool
+        if powBits >= NostrPoW.rateLimitBypassBits {
+            senderAllowed = true
+        } else {
+            var senderBucket = senderBuckets[senderKey] ?? TokenBucket(
+                capacity: senderCapacity,
+                tokens: senderCapacity,
+                refillPerSec: senderRefill,
+                lastRefill: now
+            )
+            senderAllowed = senderBucket.allow(now: now)
+            senderBuckets[senderKey] = senderBucket
+        }
 
         var contentBucket = contentBuckets[contentKey] ?? TokenBucket(
             capacity: contentCapacity,

bitchat/ViewModels/NostrInboundPipeline.swift

@@ -32,7 +32,10 @@ protocol NostrInboundPipelineContext: AnyObject {
     func recordGeoParticipant(pubkeyHex: String)
 
     // MARK: Inbound public messages
-    func handlePublicMessage(_ message: BitchatMessage)
+    /// `powBits` is the validated NIP-13 difficulty of the source event
+    /// (`NostrPoW.validatedDifficulty`); it relaxes the per-sender rate limit
+    /// downstream.
+    func handlePublicMessage(_ message: BitchatMessage, powBits: Int)
     func checkForMentions(_ message: BitchatMessage)
     func sendHapticFeedback(for message: BitchatMessage)
     func parseMentions(from content: String) -> [String]
@@ -152,6 +155,7 @@ final class NostrInboundPipeline {
         let rawTs = Date(timeIntervalSince1970: TimeInterval(event.created_at))
         let timestamp = min(rawTs, Date())
         let mentions = context.parseMentions(from: content)
+        let powBits = NostrPoW.validatedDifficulty(idHex: event.id, tags: event.tags)
         let message = BitchatMessage(
             id: event.id,
             sender: senderName,
@@ -165,7 +169,7 @@ final class NostrInboundPipeline {
         Task { @MainActor [weak context] in
             guard let context else { return }
             let isBlocked = context.isNostrBlocked(pubkeyHexLowercased: event.pubkey.lowercased())
-            context.handlePublicMessage(message)
+            context.handlePublicMessage(message, powBits: powBits)
             if !isBlocked {
                 context.checkForMentions(message)
                 context.sendHapticFeedback(for: message)
@@ -187,10 +191,12 @@ final class NostrInboundPipeline {
         guard event.isValidSignature() else { return }
         context.recordProcessedNostrEvent(event.id)
 
+        let powBits = NostrPoW.validatedDifficulty(idHex: event.id, tags: event.tags)
+
         // Sampled: fires for every geo event and floods dev logs in busy geohashes.
         geoEventLogCount += 1
         if geoEventLogCount == 1 || geoEventLogCount.isMultiple(of: TransportConfig.nostrInboundEventLogInterval) {
-            SecureLogger.debug("GeoTeleport: recv #\(geoEventLogCount) pub=\(event.pubkey.prefix(8))… tags=\(event.tags.map { "[" + $0.joined(separator: ",") + "]" }.joined(separator: ","))", category: .session)
+            SecureLogger.debug("GeoTeleport: recv #\(geoEventLogCount) pub=\(event.pubkey.prefix(8))… pow=\(powBits) tags=\(event.tags.map { "[" + $0.joined(separator: ",") + "]" }.joined(separator: ","))", category: .session)
         }
 
         if context.isNostrBlocked(pubkeyHexLowercased: event.pubkey) {
@@ -255,7 +261,7 @@ final class NostrInboundPipeline {
 
         Task { @MainActor [weak context] in
             guard let context else { return }
-            context.handlePublicMessage(message)
+            context.handlePublicMessage(message, powBits: powBits)
             context.checkForMentions(message)
             context.sendHapticFeedback(for: message)
         }
@@ -297,7 +303,9 @@ final class NostrInboundPipeline {
             context.handleDelivered(noisePayload, senderPubkey: senderPubkey, convKey: convKey)
         case .readReceipt:
             context.handleReadReceipt(noisePayload, senderPubkey: senderPubkey, convKey: convKey)
-        case .verifyChallenge, .verifyResponse:
+        // Group state travels only over mesh Noise sessions in v1; anything
+        // claiming to be group traffic over Nostr is ignored.
+        case .verifyChallenge, .verifyResponse, .groupInvite, .groupKeyUpdate, .vouch:
             break
         }
     }
@@ -349,7 +357,9 @@ final class NostrInboundPipeline {
             context.handleDelivered(payload, senderPubkey: senderPubkey, convKey: convKey)
         case .readReceipt:
             context.handleReadReceipt(payload, senderPubkey: senderPubkey, convKey: convKey)
-        case .verifyChallenge, .verifyResponse:
+        // Group state travels only over mesh Noise sessions in v1; anything
+        // claiming to be group traffic over Nostr is ignored.
+        case .verifyChallenge, .verifyResponse, .groupInvite, .groupKeyUpdate, .vouch:
             break
         }
     }
@@ -428,7 +438,9 @@ final class NostrInboundPipeline {
                             context.handleDelivered(payload, senderPubkey: senderPubkey, convKey: targetPeerID)
                         case .readReceipt:
                             context.handleReadReceipt(payload, senderPubkey: senderPubkey, convKey: targetPeerID)
-                        case .verifyChallenge, .verifyResponse:
+                        // Group state travels only over mesh Noise sessions
+                        // in v1; group traffic over Nostr is ignored.
+                        case .verifyChallenge, .verifyResponse, .groupInvite, .groupKeyUpdate, .vouch:
                             break
                         }
                     }

bitchat/Views/AppInfoView.swift

@@ -5,6 +5,11 @@ struct AppInfoView: View {
     @ThemedPalette private var palette
     @AppStorage(AppTheme.storageKey) private var appThemeRawValue = AppTheme.matrix.rawValue
 
+    /// Supplies the mesh topology map data. Nil (previews, missing wiring)
+    /// hides the topology row entirely.
+    var topologyProvider: (@MainActor () -> MeshTopologyDisplayModel)?
+    @State private var showTopology = false
+
     private var selectedTheme: AppTheme {
         AppTheme(rawValue: appThemeRawValue) ?? .matrix
     }
@@ -75,6 +80,15 @@ struct AppInfoView: View {
             ]
         }
 
+        enum Network {
+            static let title: LocalizedStringKey = "app_info.network.title"
+            static let topology = AppInfoFeatureInfo(
+                icon: "point.3.connected.trianglepath.dotted",
+                title: "app_info.network.topology.title",
+                description: "app_info.network.topology.description"
+            )
+        }
+
         enum Privacy {
             static let title: LocalizedStringKey = "app_info.privacy.title"
             static let noTracking = AppInfoFeatureInfo(
@@ -129,6 +143,11 @@ struct AppInfoView: View {
             .themedSheetBackground()
         }
         .frame(width: 600, height: 700)
+        .sheet(isPresented: $showTopology) {
+            if let topologyProvider {
+                MeshTopologyView(provider: topologyProvider)
+            }
+        }
         #else
         NavigationView {
             ScrollView {
@@ -143,6 +162,11 @@ struct AppInfoView: View {
                 }
             }
         }
+        .sheet(isPresented: $showTopology) {
+            if let topologyProvider {
+                MeshTopologyView(provider: topologyProvider)
+            }
+        }
         #endif
     }
     
@@ -199,6 +223,27 @@ struct AppInfoView: View {
                 .foregroundColor(textColor)
             }
 
+            // Network diagnostics
+            if topologyProvider != nil {
+                VStack(alignment: .leading, spacing: 16) {
+                    SectionHeader(Strings.Network.title)
+
+                    Button {
+                        showTopology = true
+                    } label: {
+                        HStack(spacing: 0) {
+                            FeatureRow(info: Strings.Network.topology)
+                            Image(systemName: "chevron.right")
+                                .font(.bitchatSystem(size: 12))
+                                .foregroundColor(secondaryTextColor)
+                        }
+                        .contentShape(Rectangle())
+                    }
+                    .buttonStyle(.plain)
+                    .accessibilityHint(Text("app_info.network.topology.hint"))
+                }
+            }
+
             // Features
             VStack(alignment: .leading, spacing: 16) {
                 SectionHeader(Strings.Features.title)

bitchat/Views/Components/PaymentChipView.swift

@@ -7,12 +7,17 @@
 //
 
 import SwiftUI
+#if os(iOS)
+import UIKit
+#else
+import AppKit
+#endif
 
 struct PaymentChipView: View {
     @Environment(\.colorScheme) private var colorScheme
     @Environment(\.openURL) private var openURL
     @ThemedPalette private var palette
-    
+
     enum PaymentType {
         case cashu(String)
         case lightning(String)
@@ -35,14 +40,33 @@ struct PaymentChipView: View {
                 return URL(string: link)
             }
         }
-        
+
+        /// The bare `cashuA…`/`cashuB…` bearer string, when this is a Cashu chip.
+        var cashuToken: String? {
+            if case .cashu(let link) = self {
+                return CashuTokenDecoder.bareToken(from: link)
+            }
+            return nil
+        }
+
+        /// Web fallback for redemption when no wallet handles `cashu:` URLs.
+        /// The token only reaches the site the user's browser loads; the app
+        /// itself never contacts a mint.
+        var cashuWebRedeemURL: URL? {
+            guard let token = cashuToken,
+                  let enc = token.addingPercentEncoding(withAllowedCharacters: Self.cashuAllowedCharacters) else {
+                return nil
+            }
+            return URL(string: "https://redeem.cashu.me/?token=\(enc)")
+        }
+
         var emoji: String {
             switch self {
             case .cashu:        "🥜"
             case .lightning:    "⚡"
             }
         }
-        
+
         var label: String {
             switch self {
             case .cashu:
@@ -52,27 +76,56 @@ struct PaymentChipView: View {
             }
         }
     }
-    
+
     let paymentType: PaymentType
-    
+    /// Decoded once at construction; tokens are capped in size so this is
+    /// cheap, and rows re-render often enough that lazy decode in `body`
+    /// would just repeat the work.
+    private let cashuInfo: CashuTokenDecoder.TokenInfo?
+
+    init(paymentType: PaymentType) {
+        self.paymentType = paymentType
+        if case .cashu(let link) = paymentType {
+            self.cashuInfo = CashuTokenDecoder.decode(link)
+        } else {
+            self.cashuInfo = nil
+        }
+    }
+
     private var fgColor: Color { palette.primary }
     private var bgColor: Color {
         palette.secondary.opacity(colorScheme == .dark ? 0.18 : 0.12)
     }
     private var border: Color { fgColor.opacity(0.25) }
-    
+
+    /// "500 sat · mint.example.com", degrading to the generic label when the
+    /// token didn't decode (V4 payloads we can't walk, malformed input…).
+    private var primaryLabel: String {
+        guard let info = cashuInfo else { return paymentType.label }
+        var parts: [String] = []
+        if let amount = info.displayAmount { parts.append(amount) }
+        if let host = info.mintHost { parts.append(host) }
+        return parts.isEmpty ? paymentType.label : parts.joined(separator: " · ")
+    }
+
+    private var memoLabel: String? { cashuInfo?.memo }
+
     var body: some View {
         Button {
-            #if os(iOS)
-            if let url = paymentType.url { openURL(url) }
-            #else
-            if let url = paymentType.url { NSWorkspace.shared.open(url) }
-            #endif
+            primaryAction()
         } label: {
             HStack(spacing: 6) {
                 Text(paymentType.emoji)
-                Text(paymentType.label)
-                    .bitchatFont(size: 12, weight: .semibold)
+                VStack(alignment: .leading, spacing: 1) {
+                    Text(primaryLabel)
+                        .bitchatFont(size: 12, weight: .semibold)
+                    if let memoLabel {
+                        Text(memoLabel)
+                            .bitchatFont(size: 10)
+                            .opacity(0.7)
+                            .lineLimit(1)
+                    }
+                }
             }
             .padding(.vertical, 6)
             .padding(.horizontal, 12)
@@ -87,13 +140,102 @@ struct PaymentChipView: View {
             .foregroundColor(fgColor)
         }
         .buttonStyle(.plain)
+        .contextMenu {
+            if let token = paymentType.cashuToken {
+                Button {
+                    copyToPasteboard(token)
+                } label: {
+                    Label(String(localized: "content.payment.copy_token", comment: "Context menu action copying a Cashu token to the pasteboard"), systemImage: "doc.on.doc")
+                }
+                Button {
+                    redeemCashu()
+                } label: {
+                    Label(String(localized: "content.payment.redeem_wallet", comment: "Context menu action opening a Cashu token in an ecash wallet app"), systemImage: "wallet.pass")
+                }
+                if let webURL = paymentType.cashuWebRedeemURL {
+                    Button {
+                        openExternalURL(webURL)
+                    } label: {
+                        Label(String(localized: "content.payment.redeem_web", comment: "Context menu action opening a Cashu token in the web redemption page"), systemImage: "safari")
+                    }
+                }
+            }
+        }
+        .accessibilityLabel(Text(verbatim: accessibilityText))
+    }
+
+    private var accessibilityText: String {
+        var text = "\(paymentType.label): \(primaryLabel)"
+        if let memoLabel { text += ", \(memoLabel)" }
+        return text
+    }
+
+    // MARK: - Actions
+
+    private func primaryAction() {
+        switch paymentType {
+        case .cashu:
+            redeemCashu()
+        case .lightning:
+            #if os(iOS)
+            if let url = paymentType.url { openURL(url) }
+            #else
+            if let url = paymentType.url { NSWorkspace.shared.open(url) }
+            #endif
+        }
+    }
+
+    /// Redemption is delegated: try a wallet registered for `cashu:` URLs
+    /// first, then fall back to the web redemption page. Uses the platform
+    /// opener directly (not the `openURL` environment) because the message
+    /// list overrides that action for cashu/lightning schemes without a
+    /// fallback path.
+    private func redeemCashu() {
+        let walletURL = paymentType.url
+        let webURL = paymentType.cashuWebRedeemURL
+        #if os(iOS)
+        if let walletURL {
+            UIApplication.shared.open(walletURL, options: [:]) { accepted in
+                if !accepted, let webURL {
+                    UIApplication.shared.open(webURL)
+                }
+            }
+        } else if let webURL {
+            UIApplication.shared.open(webURL)
+        }
+        #else
+        if let walletURL, NSWorkspace.shared.urlForApplication(toOpen: walletURL) != nil {
+            NSWorkspace.shared.open(walletURL)
+        } else if let webURL {
+            NSWorkspace.shared.open(webURL)
+        } else if let walletURL {
+            NSWorkspace.shared.open(walletURL)
+        }
+        #endif
+    }
+
+    private func openExternalURL(_ url: URL) {
+        #if os(iOS)
+        UIApplication.shared.open(url)
+        #else
+        NSWorkspace.shared.open(url)
+        #endif
+    }
+
+    private func copyToPasteboard(_ string: String) {
+        #if os(iOS)
+        UIPasteboard.general.string = string
+        #else
+        NSPasteboard.general.clearContents()
+        NSPasteboard.general.setString(string, forType: .string)
+        #endif
     }
 }
 
 #Preview {
     let cashuLink = "https://example.com/cashu"
     let lightningLink = "https://example.com/lightning"
-    
+
     List {
         HStack {
             PaymentChipView(paymentType: .cashu(cashuLink))

bitchat/Views/ContentHeaderView.swift

@@ -1,21 +1,17 @@
 import SwiftUI
-#if os(iOS)
-import UIKit
-#endif
 
 struct ContentHeaderView: View {
     @EnvironmentObject private var appChromeModel: AppChromeModel
     @EnvironmentObject private var verificationModel: VerificationModel
     @EnvironmentObject private var locationChannelsModel: LocationChannelsModel
     @EnvironmentObject private var peerListModel: PeerListModel
+    @EnvironmentObject private var boardAlertsModel: BoardAlertsModel
     @Environment(\.dynamicTypeSize) private var dynamicTypeSize
     @Environment(\.appTheme) private var theme
     @ThemedPalette private var palette
 
     @Binding var showSidebar: Bool
     @Binding var showVerifySheet: Bool
-    @Binding var showLocationNotes: Bool
-    @Binding var notesGeohash: String?
     var isNicknameFieldFocused: FocusState<Bool>.Binding
 
     let headerHeight: CGFloat
@@ -25,6 +21,14 @@ struct ContentHeaderView: View {
     /// Courier envelopes this device is carrying for offline third parties.
     @State private var carriedMailCount = 0
 
+    /// Unified notices sheet (board posts + location notes) for the current
+    /// channel context.
+    @State private var showNotices = false
+
+    /// Board posts mirrored from the store so the pin icon can show when the
+    /// current scope has notices.
+    @State private var boardPosts: [BoardPostPacket] = []
+
     var body: some View {
         HStack(spacing: 0) {
             Text(verbatim: "bitchat/")
@@ -91,6 +95,19 @@ struct ContentHeaderView: View {
             }()
 
             HStack(spacing: 2) {
+                if locationChannelsModel.gatewayEnabled {
+                    Image(systemName: "globe")
+                        .font(.bitchatSystem(size: 12))
+                        .foregroundColor(palette.secondary.opacity(0.8))
+                        .headerTapTarget()
+                        .accessibilityLabel(
+                            String(localized: "content.accessibility.gateway_active", defaultValue: "Internet gateway active, sharing your connection with the mesh", comment: "Accessibility label for the internet gateway indicator")
+                        )
+                        .help(
+                            String(localized: "content.header.gateway_active", defaultValue: "Sharing your internet connection with nearby mesh peers", comment: "Tooltip for the internet gateway indicator")
+                        )
+                }
+
                 if carriedMailCount > 0 {
                     Image(systemName: "figure.walk")
                         .font(.bitchatSystem(size: 12))
@@ -121,23 +138,41 @@ struct ContentHeaderView: View {
                     )
                 }
 
-                if case .mesh = locationChannelsModel.selectedChannel,
-                   locationChannelsModel.permissionState == .authorized {
-                    Button(action: {
-                        locationChannelsModel.enableAndRefresh()
-                        notesGeohash = locationChannelsModel.currentBuildingGeohash
-                        showLocationNotes = true
-                    }) {
-                        Image(systemName: "note.text")
-                            .font(.bitchatSystem(size: 12))
-                            .foregroundColor(Color.orange.opacity(0.8))
-                            .headerTapTarget()
+                Button(action: {
+                    var scopes: Set<String> = [""]
+                    if let geoScope = noticesGeoScope {
+                        scopes.insert(geoScope)
                     }
-                    .buttonStyle(.plain)
-                    .accessibilityLabel(
-                        String(localized: "content.accessibility.location_notes", comment: "Accessibility label for location notes button")
-                    )
+                    boardAlertsModel.markSeen(forScopes: scopes)
+                    showNotices = true
+                }) {
+                    // Fill marks unseen new pins; the tint says the current
+                    // scope has notices at all.
+                    Image(systemName: unseenNoticesCount > 0 ? "pin.fill" : "pin")
+                        .font(.bitchatSystem(size: 12))
+                        .foregroundColor(
+                            scopeHasNotices || unseenNoticesCount > 0
+                                ? Color.orange.opacity(0.8)
+                                : palette.secondary.opacity(0.9)
+                        )
+                        .headerTapTarget()
                 }
+                .buttonStyle(.plain)
+                .accessibilityLabel(
+                    String(localized: "content.accessibility.notices", defaultValue: "Notices", comment: "Accessibility label for the notices button")
+                )
+                .accessibilityValue(
+                    unseenNoticesCount > 0
+                        ? String(
+                            format: String(localized: "content.accessibility.notices_new", defaultValue: "%lld new", comment: "Accessibility value for the notices button when unseen pins arrived"),
+                            locale: .current,
+                            unseenNoticesCount
+                        )
+                        : ""
+                )
+                .help(
+                    String(localized: "content.header.notices", defaultValue: "Notices: pinned posts for this area and the mesh", comment: "Tooltip for the notices button")
+                )
 
                 if case .location(let channel) = locationChannelsModel.selectedChannel {
                     Button(action: { locationChannelsModel.toggleBookmark(channel.geohash) }) {
@@ -237,47 +272,21 @@ struct ContentHeaderView: View {
         .onReceive(CourierStore.shared.$carriedCount) { count in
             carriedMailCount = count
         }
+        .onReceive(BoardStore.shared.$postsSnapshot) { posts in
+            boardPosts = posts
+        }
         .sheet(isPresented: $appChromeModel.isLocationChannelsSheetPresented) {
             LocationChannelsSheet(isPresented: $appChromeModel.isLocationChannelsSheetPresented)
                 .environmentObject(locationChannelsModel)
                 .environmentObject(peerListModel)
         }
-        .sheet(isPresented: $showLocationNotes, onDismiss: {
-            notesGeohash = nil
-        }) {
-            Group {
-                if let geohash = notesGeohash ?? locationChannelsModel.currentBuildingGeohash {
-                    LocationNotesView(
-                        geohash: geohash,
-                        senderNickname: appChromeModel.nickname
-                    )
-                    .environmentObject(locationChannelsModel)
-                } else {
-                    ContentLocationNotesUnavailableView(
-                        showLocationNotes: $showLocationNotes,
-                        headerHeight: headerHeight
-                    )
-                    .environmentObject(locationChannelsModel)
-                }
-            }
-            .onAppear {
-                locationChannelsModel.enableLocationChannels()
-                locationChannelsModel.beginLiveRefresh()
-            }
-            .onDisappear {
-                locationChannelsModel.endLiveRefresh()
-            }
-            .onChange(of: locationChannelsModel.availableChannels) { channels in
-                if let current = channels.first(where: { $0.level == .building })?.geohash,
-                   notesGeohash != current {
-                    notesGeohash = current
-                    #if os(iOS)
-                    let generator = UIImpactFeedbackGenerator(style: .light)
-                    generator.prepare()
-                    generator.impactOccurred()
-                    #endif
-                }
-            }
+        .sheet(isPresented: $showNotices) {
+            NoticesView(
+                senderNickname: appChromeModel.nickname,
+                board: appChromeModel.boardManager,
+                initialTab: initialNoticesTab
+            )
+            .environmentObject(locationChannelsModel)
         }
         .onAppear {
             locationChannelsModel.refreshMeshChannelsIfNeeded()
@@ -311,6 +320,36 @@ private extension ContentHeaderView {
         dynamicTypeSize.isAccessibilitySize ? 2 : 1
     }
 
+    /// Open the notices sheet on the tab matching the current channel: the
+    /// geohash channel's notices, or the mesh-local board in mesh chat.
+    var initialNoticesTab: NoticesView.Tab {
+        if case .location = locationChannelsModel.selectedChannel {
+            return .geo
+        }
+        return .mesh
+    }
+
+    /// The geo scope the notices sheet would open on: the selected location
+    /// channel, or the device's building geohash when chatting on mesh.
+    var noticesGeoScope: String? {
+        if case .location(let channel) = locationChannelsModel.selectedChannel {
+            return channel.geohash
+        }
+        return locationChannelsModel.currentBuildingGeohash
+    }
+
+    /// Whether either tab of the notices sheet currently has content.
+    var scopeHasNotices: Bool {
+        boardPosts.contains { $0.geohash.isEmpty || $0.geohash == noticesGeoScope }
+    }
+
+    /// New pins in either visible scope since the sheet was last opened.
+    var unseenNoticesCount: Int {
+        let meshCount = boardAlertsModel.unseenCount(forGeohash: "")
+        let geoCount = noticesGeoScope.map { boardAlertsModel.unseenCount(forGeohash: $0) } ?? 0
+        return meshCount + geoCount
+    }
+
     /// Whether anyone is actually reachable on the current channel — the
     /// state the count icon's color encodes visually.
     var headerPeersReachable: Bool {
@@ -334,37 +373,3 @@ private extension ContentHeaderView {
         }
     }
 }
-
-private struct ContentLocationNotesUnavailableView: View {
-    @EnvironmentObject private var locationChannelsModel: LocationChannelsModel
-    @ThemedPalette private var palette
-
-    @Binding var showLocationNotes: Bool
-
-    let headerHeight: CGFloat
-
-    var body: some View {
-        VStack(spacing: 12) {
-            HStack {
-                Text("content.notes.title")
-                    .bitchatFont(size: 16, weight: .bold)
-                Spacer()
-                SheetCloseButton { showLocationNotes = false }
-                    .foregroundColor(palette.primary)
-            }
-            .frame(minHeight: headerHeight)
-            .padding(.horizontal, 12)
-            .themedChromePanel(edge: .top)
-            Text("content.notes.location_unavailable")
-                .bitchatFont(size: 14)
-                .foregroundColor(palette.secondary)
-            Button("content.location.enable") {
-                locationChannelsModel.enableAndRefresh()
-            }
-            .buttonStyle(.bordered)
-            Spacer()
-        }
-        .themedSheetBackground()
-        .foregroundColor(palette.primary)
-    }
-}

bitchat/Views/ContentSheetViews.swift

@@ -221,6 +221,13 @@ private struct ContentPeopleListView: View {
                             }
                         )
                     } else {
+                        GroupChatList(
+                            groups: peerListModel.groupRows,
+                            onTapGroup: { peerID in
+                                peerListModel.startConversation(with: peerID)
+                                showSidebar = true
+                            }
+                        )
                         MeshPeerList(
                             onTapPeer: { peerID in
                                 peerListModel.startConversation(with: peerID)
@@ -455,6 +462,10 @@ private struct ContentPrivateChatSheetView: View {
     }
 
     private var privacyCaptionText: String {
+        // Group chats are ChaCha20-Poly1305 sealed to the roster's shared key.
+        if privateConversationModel.selectedPeerID?.isGroup == true {
+            return String(localized: "content.private.caption_group", comment: "Caption above the group chat composer noting messages are encrypted to group members")
+        }
         // Geohash DMs are NIP-17 gift-wrapped — always end-to-end encrypted,
         // even though they carry no Noise session status. Mesh DMs earn the
         // "encrypted" claim only once the Noise handshake has secured.
@@ -503,30 +514,39 @@ private struct ContentPrivateHeaderInfoButton: View {
 
     var body: some View {
         Button(action: {
+            // A group has no single fingerprint to show.
+            guard !headerState.isGroupConversation else { return }
             appChromeModel.showFingerprint(for: headerState.headerPeerID)
         }) {
             HStack(spacing: 6) {
-                switch headerState.availability {
-                case .bluetoothConnected:
-                    Image(systemName: "dot.radiowaves.left.and.right")
+                if headerState.isGroupConversation {
+                    Image(systemName: "person.3.fill")
                         .font(.bitchatSystem(size: 14))
                         .foregroundColor(palette.primary)
-                        .accessibilityLabel(String(localized: "content.accessibility.connected_mesh", comment: "Accessibility label for mesh-connected peer indicator"))
-                case .meshReachable:
-                    Image(systemName: "point.3.filled.connected.trianglepath.dotted")
-                        .font(.bitchatSystem(size: 14))
-                        .foregroundColor(palette.primary)
-                        .accessibilityLabel(String(localized: "content.accessibility.reachable_mesh", comment: "Accessibility label for mesh-reachable peer indicator"))
-                case .nostrAvailable:
-                    Image(systemName: "globe")
-                        .font(.bitchatSystem(size: 14))
-                        .foregroundColor(.purple)
-                        .accessibilityLabel(String(localized: "content.accessibility.available_nostr", comment: "Accessibility label for Nostr-available peer indicator"))
-                case .offline:
-                    // Absence of a glyph was the only offline signal; say it.
-                    Text("mesh_peers.state.offline")
-                        .bitchatFont(size: 11)
-                        .foregroundColor(palette.secondary)
+                        .accessibilityLabel(String(localized: "content.accessibility.group_chat", comment: "Accessibility label for the group chat indicator"))
+                } else {
+                    switch headerState.availability {
+                    case .bluetoothConnected:
+                        Image(systemName: "dot.radiowaves.left.and.right")
+                            .font(.bitchatSystem(size: 14))
+                            .foregroundColor(palette.primary)
+                            .accessibilityLabel(String(localized: "content.accessibility.connected_mesh", comment: "Accessibility label for mesh-connected peer indicator"))
+                    case .meshReachable:
+                        Image(systemName: "point.3.filled.connected.trianglepath.dotted")
+                            .font(.bitchatSystem(size: 14))
+                            .foregroundColor(palette.primary)
+                            .accessibilityLabel(String(localized: "content.accessibility.reachable_mesh", comment: "Accessibility label for mesh-reachable peer indicator"))
+                    case .nostrAvailable:
+                        Image(systemName: "globe")
+                            .font(.bitchatSystem(size: 14))
+                            .foregroundColor(.purple)
+                            .accessibilityLabel(String(localized: "content.accessibility.available_nostr", comment: "Accessibility label for Nostr-available peer indicator"))
+                    case .offline:
+                        // Absence of a glyph was the only offline signal; say it.
+                        Text("mesh_peers.state.offline")
+                            .bitchatFont(size: 11)
+                            .foregroundColor(palette.secondary)
+                    }
                 }
 
                 Text(headerState.displayName)
@@ -571,7 +591,9 @@ private struct ContentPrivateHeaderInfoButton: View {
             )
         )
         .accessibilityHint(
-            String(localized: "content.accessibility.view_fingerprint_hint", comment: "Accessibility hint for viewing encryption fingerprint")
+            headerState.isGroupConversation
+            ? ""
+            : String(localized: "content.accessibility.view_fingerprint_hint", comment: "Accessibility hint for viewing encryption fingerprint")
         )
         .frame(minHeight: headerHeight)
     }

bitchat/Views/ContentView.swift

@@ -49,8 +49,6 @@ struct ContentView: View {
     @State private var isAtBottomPrivate = true
     @State private var autocompleteDebounceTimer: Timer?
     @State private var showVerifySheet = false
-    @State private var showLocationNotes = false
-    @State private var notesGeohash: String?
     @State private var imagePreviewURL: URL?
     #if os(iOS)
     @State private var showImagePicker = false
@@ -149,7 +147,7 @@ struct ContentView: View {
             #endif
         }
         .sheet(isPresented: $appChromeModel.isAppInfoPresented) {
-            AppInfoView()
+            AppInfoView(topologyProvider: { appChromeModel.meshTopologyDisplayModel() })
         }
         .sheet(isPresented: Binding(
             get: { appChromeModel.showingFingerprintFor != nil && !showSidebar && selectedPrivatePeerID == nil },
@@ -269,8 +267,6 @@ struct ContentView: View {
         ContentHeaderView(
             showSidebar: $showSidebar,
             showVerifySheet: $showVerifySheet,
-            showLocationNotes: $showLocationNotes,
-            notesGeohash: $notesGeohash,
             isNicknameFieldFocused: $isNicknameFieldFocused,
             headerHeight: headerHeight,
             headerPeerIconSize: headerPeerIconSize,

bitchat/Views/FingerprintView.swift

@@ -37,6 +37,14 @@ struct FingerprintView: View {
         }
         static let markVerified: LocalizedStringKey = "fingerprint.action.mark_verified"
         static let removeVerification: LocalizedStringKey = "fingerprint.action.remove_verification"
+        static let vouchedBadge: LocalizedStringKey = "fingerprint.badge.vouched"
+        static func vouchedBy(_ count: Int) -> String {
+            String(
+                format: String(localized: "fingerprint.message.vouched_by", comment: "How many people the user verified have vouched for this peer"),
+                locale: .current,
+                count
+            )
+        }
         static func unknownPeer() -> String {
             String(localized: "common.unknown", comment: "Label for an unknown peer")
         }
@@ -146,6 +154,41 @@ struct FingerprintView: View {
                         }
                 }
                 
+                // Vouched (transitively verified) status: shown whenever the
+                // peer isn't explicitly verified but people I verified vouch
+                // for them, independent of the current session state.
+                if fingerprintState.isVouched && !fingerprintState.isVerified {
+                    VStack(spacing: 8) {
+                        HStack(spacing: 6) {
+                            Image(systemName: "checkmark.seal")
+                                .font(.bitchatSystem(size: 14))
+                                .foregroundColor(.teal)
+                            Text(Strings.vouchedBadge)
+                                .bitchatFont(size: 14, weight: .bold)
+                                .foregroundColor(.teal)
+                        }
+                        .frame(maxWidth: .infinity)
+
+                        Text(Strings.vouchedBy(fingerprintState.voucherCount))
+                            .bitchatFont(size: 12)
+                            .foregroundColor(textColor.opacity(0.7))
+                            .multilineTextAlignment(.center)
+                            .frame(maxWidth: .infinity)
+
+                        if !fingerprintState.voucherNames.isEmpty {
+                            Text(fingerprintState.voucherNames.joined(separator: ", "))
+                                .bitchatFont(size: 12)
+                                .foregroundColor(textColor.opacity(0.7))
+                                .multilineTextAlignment(.center)
+                                .lineLimit(nil)
+                                .fixedSize(horizontal: false, vertical: true)
+                                .frame(maxWidth: .infinity)
+                        }
+                    }
+                    .padding(.top, 8)
+                    .accessibilityElement(children: .combine)
+                }
+
                 // Verification status
                 if fingerprintState.canToggleVerification {
                     VStack(spacing: 12) {

bitchat/Views/GroupChatList.swift

@@ -0,0 +1,86 @@
+import BitFoundation
+import SwiftUI
+
+/// Compact "groups" section for the people sheet: one row per private group
+/// this device belongs to, tappable to open the group chat window.
+struct GroupChatList: View {
+    @ThemedPalette private var palette
+
+    let groups: [GroupChatRow]
+    let onTapGroup: (PeerID) -> Void
+
+    private enum Strings {
+        static let header = String(localized: "groups.section.header", comment: "Section header above the private groups list")
+        static let creator = String(localized: "groups.state.creator", comment: "State label for a group the user created")
+        static let unread = String(localized: "mesh_peers.state.unread", comment: "State label for a peer with unread private messages")
+        static let newMessagesTooltip = String(localized: "mesh_peers.tooltip.new_messages", comment: "Tooltip for the unread messages indicator")
+        static let openGroupHint = String(localized: "groups.accessibility.open_group_hint", comment: "Accessibility hint on a group row explaining activation opens the group chat")
+        static let memberCountFormat = String(localized: "groups.member_count %@", comment: "Member count shown next to a group name; placeholder is the count")
+    }
+
+    var body: some View {
+        if !groups.isEmpty {
+            VStack(alignment: .leading, spacing: 0) {
+                Text(Strings.header)
+                    .bitchatFont(size: 11, weight: .medium)
+                    .foregroundColor(palette.secondary)
+                    .padding(.horizontal)
+                    .padding(.top, 10)
+                    .padding(.bottom, 2)
+                    .accessibilityAddTraits(.isHeader)
+
+                ForEach(groups) { group in
+                    HStack(spacing: 4) {
+                        Image(systemName: "person.3.fill")
+                            .font(.bitchatSystem(size: 10))
+                            .foregroundColor(palette.primary)
+
+                        Text("#\(group.name)")
+                            .bitchatFont(size: 14)
+                            .foregroundColor(palette.primary)
+                            .lineLimit(1)
+                            .truncationMode(.tail)
+
+                        Text(String(format: Strings.memberCountFormat, locale: .current, "\(group.memberCount)"))
+                            .bitchatFont(size: 12)
+                            .foregroundColor(palette.secondary)
+
+                        if group.isCreator {
+                            Image(systemName: "crown.fill")
+                                .font(.bitchatSystem(size: 9))
+                                .foregroundColor(.yellow)
+                                .help(Strings.creator)
+                        }
+
+                        Spacer()
+
+                        if group.hasUnread {
+                            Image(systemName: "envelope.fill")
+                                .font(.bitchatSystem(size: 10))
+                                .foregroundColor(.orange)
+                                .help(Strings.newMessagesTooltip)
+                        }
+                    }
+                    .padding(.horizontal)
+                    .padding(.vertical, 6)
+                    .contentShape(Rectangle())
+                    .onTapGesture { onTapGroup(group.peerID) }
+                    .accessibilityElement(children: .ignore)
+                    .accessibilityLabel(accessibilityDescription(for: group))
+                    .accessibilityAddTraits(.isButton)
+                    .accessibilityHint(Strings.openGroupHint)
+                }
+            }
+        }
+    }
+
+    private func accessibilityDescription(for group: GroupChatRow) -> String {
+        var parts: [String] = [
+            group.name,
+            String(format: Strings.memberCountFormat, locale: .current, "\(group.memberCount)")
+        ]
+        if group.isCreator { parts.append(Strings.creator) }
+        if group.hasUnread { parts.append(Strings.unread) }
+        return parts.joined(separator: ", ")
+    }
+}

bitchat/Views/LocationChannelsSheet.swift

@@ -27,6 +27,8 @@ struct LocationChannelsSheet: View {
         static let removeAccess: LocalizedStringKey = "location_channels.action.remove_access"
         static let torTitle: LocalizedStringKey = "location_channels.tor.title"
         static let torSubtitle: LocalizedStringKey = "location_channels.tor.subtitle"
+        static let gatewayTitle: LocalizedStringKey = "location_channels.gateway.title"
+        static let gatewaySubtitle: LocalizedStringKey = "location_channels.gateway.subtitle"
         static let toggleOn: LocalizedStringKey = "common.toggle.on"
         static let toggleOff: LocalizedStringKey = "common.toggle.off"
 
@@ -244,6 +246,8 @@ struct LocationChannelsSheet: View {
                     sectionDivider
                     torToggleSection
                         .padding(.top, 12)
+                    gatewayToggleSection
+                        .padding(.top, 8)
                     Button(action: SystemSettings.location.open) {
                         Text(Strings.removeAccess)
                             .bitchatFont(size: 12)
@@ -508,6 +512,32 @@ extension LocationChannelsSheet {
         .cornerRadius(8)
     }
 
+    private var gatewayToggleBinding: Binding<Bool> {
+        Binding(
+            get: { locationChannelsModel.gatewayEnabled },
+            set: { locationChannelsModel.setGatewayEnabled($0) }
+        )
+    }
+
+    private var gatewayToggleSection: some View {
+        VStack(alignment: .leading, spacing: 8) {
+            Toggle(isOn: gatewayToggleBinding) {
+                VStack(alignment: .leading, spacing: 2) {
+                    Text(Strings.gatewayTitle)
+                        .bitchatFont(size: 12, weight: .semibold)
+                        .foregroundColor(palette.primary)
+                    Text(Strings.gatewaySubtitle)
+                        .bitchatFont(size: 11)
+                        .foregroundColor(palette.secondary)
+                }
+            }
+            .toggleStyle(IRCToggleStyle(accent: palette.accent, onLabel: Strings.toggleOn, offLabel: Strings.toggleOff))
+        }
+        .padding(12)
+        .background(palette.secondary.opacity(0.12))
+        .cornerRadius(8)
+    }
+
     private var standardGreen: Color { palette.primary }
     private var standardBlue: Color { palette.accentBlue }
 }

bitchat/Views/LocationNotesView.swift

@@ -1,304 +0,0 @@
-import SwiftUI
-
-struct LocationNotesView: View {
-    @StateObject private var manager: LocationNotesManager
-    let geohash: String
-    let senderNickname: String
-    let onNotesCountChanged: ((Int) -> Void)?
-
-    @ThemedPalette private var palette
-    @Environment(\.dynamicTypeSize) private var dynamicTypeSize
-    @EnvironmentObject private var locationChannelsModel: LocationChannelsModel
-    @Environment(\.dismiss) private var dismiss
-    @State private var draft: String = ""
-
-    init(
-        geohash: String,
-        senderNickname: String,
-        onNotesCountChanged: ((Int) -> Void)? = nil,
-        manager: LocationNotesManager? = nil
-    ) {
-        let gh = geohash.lowercased()
-        self.geohash = gh
-        self.senderNickname = senderNickname
-        self.onNotesCountChanged = onNotesCountChanged
-        _manager = StateObject(wrappedValue: manager ?? LocationNotesManager(geohash: gh))
-    }
-
-    private var backgroundColor: Color { palette.background }
-    private var accentGreen: Color { palette.accent }
-    private var maxDraftLines: Int { dynamicTypeSize.isAccessibilitySize ? 5 : 3 }
-
-    private enum Strings {
-        static let description: LocalizedStringKey = "location_notes.description"
-        static let loadingRecent: LocalizedStringKey = "location_notes.loading_recent"
-        static let relaysPaused: LocalizedStringKey = "location_notes.relays_paused"
-        static let noRelaysNearby: LocalizedStringKey = "location_notes.no_relays_nearby"
-        static let retry: LocalizedStringKey = "location_notes.action.retry"
-        static let relaysRetryHint: LocalizedStringKey = "location_notes.relays_retry_hint"
-        static let loadingNotes: LocalizedStringKey = "location_notes.loading_notes"
-        static let emptyTitle: LocalizedStringKey = "location_notes.empty_title"
-        static let emptySubtitle: LocalizedStringKey = "location_notes.empty_subtitle"
-        static let dismissError: LocalizedStringKey = "location_notes.action.dismiss"
-        static let addPlaceholder: LocalizedStringKey = "location_notes.placeholder"
-    }
-
-    var body: some View {
-#if os(macOS)
-        VStack(spacing: 0) {
-            ScrollView {
-                VStack(spacing: 0) {
-                    headerSection
-                    notesContent
-                }
-            }
-            .themedSurface()
-            inputSection
-        }
-        .frame(minWidth: 420, idealWidth: 440, minHeight: 620, idealHeight: 680)
-        .themedSheetBackground()
-        .onDisappear { manager.cancel() }
-        .onChange(of: geohash) { newValue in
-            manager.setGeohash(newValue)
-        }
-        .onAppear { onNotesCountChanged?(manager.notes.count) }
-        .onChange(of: manager.notes.count) { newValue in
-            onNotesCountChanged?(newValue)
-        }
-#else
-        NavigationView {
-            VStack(spacing: 0) {
-                headerSection
-                ScrollView {
-                    notesContent
-                }
-                .frame(maxWidth: .infinity, maxHeight: .infinity)
-                inputSection
-            }
-            .themedSurface()
-            #if os(iOS)
-            .navigationBarTitleDisplayMode(.inline)
-            .navigationBarHidden(true)
-            #else
-            .navigationTitle("")
-            #endif
-        }
-        .themedSheetBackground()
-        .onDisappear { manager.cancel() }
-        .onChange(of: geohash) { newValue in
-            manager.setGeohash(newValue)
-        }
-        .onAppear { onNotesCountChanged?(manager.notes.count) }
-        .onChange(of: manager.notes.count) { newValue in
-            onNotesCountChanged?(newValue)
-        }
-#endif
-    }
-
-    private var closeButton: some View {
-        SheetCloseButton { dismiss() }
-    }
-
-    private var headerSection: some View {
-        let count = manager.notes.count
-        return VStack(alignment: .leading, spacing: 8) {
-            HStack(spacing: 12) {
-                Text(headerTitle(for: count))
-                    .bitchatFont(size: 18)
-                Spacer()
-                closeButton
-            }
-            if let building = locationChannelsModel.locationName(for: .building), !building.isEmpty {
-                Text(building)
-                    .bitchatFont(size: 12)
-                    .foregroundColor(accentGreen)
-            } else if let block = locationChannelsModel.locationName(for: .block), !block.isEmpty {
-                Text(block)
-                    .bitchatFont(size: 12)
-                    .foregroundColor(accentGreen)
-            }
-            Text(Strings.description)
-                .bitchatFont(size: 12)
-                .foregroundColor(palette.secondary)
-                .fixedSize(horizontal: false, vertical: true)
-            if manager.state == .noRelays {
-                Text(Strings.relaysPaused)
-                    .bitchatFont(size: 11)
-                    .foregroundColor(palette.secondary)
-            }
-        }
-        .padding(.horizontal, 16)
-        .padding(.top, 16)
-        .padding(.bottom, 12)
-        .themedSurface()
-    }
-
-    private func headerTitle(for count: Int) -> String {
-        String(
-            format: String(localized: "location_notes.header", comment: "Header displaying the geohash and localized note count"),
-            locale: .current,
-            "\(geohash) ± 1", count
-        )
-    }
-
-    private var notesContent: some View {
-        LazyVStack(alignment: .leading, spacing: 12) {
-            if manager.state == .noRelays {
-                noRelaysRow
-            } else if manager.state == .loading && !manager.initialLoadComplete {
-                loadingRow
-            } else if manager.notes.isEmpty {
-                emptyRow
-            } else {
-                ForEach(manager.notes) { note in
-                    noteRow(note)
-                }
-            }
-
-            if let error = manager.errorMessage, manager.state != .noRelays {
-                errorRow(message: error)
-            }
-        }
-        .padding(.horizontal, 16)
-        .padding(.vertical, 8)
-    }
-
-    private func noteRow(_ note: LocationNotesManager.Note) -> some View {
-        let baseName = note.displayName.split(separator: "#", maxSplits: 1, omittingEmptySubsequences: false).first.map(String.init) ?? note.displayName
-        let ts = timestampText(for: note.createdAt)
-        return VStack(alignment: .leading, spacing: 2) {
-            HStack(spacing: 6) {
-                Text(verbatim: "@\(baseName)")
-                    .bitchatFont(size: 12, weight: .semibold)
-                if !ts.isEmpty {
-                    Text(ts)
-                        .bitchatFont(size: 11)
-                        .foregroundColor(palette.secondary)
-                }
-                Spacer()
-            }
-            Text(note.content)
-                .bitchatFont(size: 14)
-                .fixedSize(horizontal: false, vertical: true)
-        }
-        .padding(.vertical, 4)
-    }
-
-    private var noRelaysRow: some View {
-        VStack(alignment: .leading, spacing: 4) {
-            Text(Strings.noRelaysNearby)
-                .bitchatFont(size: 13, weight: .semibold)
-            Text(Strings.relaysRetryHint)
-                .bitchatFont(size: 12)
-                .foregroundColor(palette.secondary)
-            Button(Strings.retry) { manager.refresh() }
-                .bitchatFont(size: 12)
-                .buttonStyle(.plain)
-        }
-        .padding(.vertical, 6)
-    }
-
-    private var loadingRow: some View {
-        HStack(spacing: 10) {
-            ProgressView()
-            Text(Strings.loadingNotes)
-                .bitchatFont(size: 12)
-                .foregroundColor(palette.secondary)
-            Spacer()
-        }
-        .padding(.vertical, 8)
-    }
-
-    private var emptyRow: some View {
-        VStack(alignment: .leading, spacing: 4) {
-            Text(Strings.emptyTitle)
-                .bitchatFont(size: 13, weight: .semibold)
-            Text(Strings.emptySubtitle)
-                .bitchatFont(size: 12)
-                .foregroundColor(palette.secondary)
-        }
-        .padding(.vertical, 6)
-    }
-
-    private func errorRow(message: String) -> some View {
-        VStack(alignment: .leading, spacing: 4) {
-            HStack(spacing: 6) {
-                Image(systemName: "exclamationmark.triangle.fill")
-                    .bitchatFont(size: 12)
-                Text(message)
-                    .bitchatFont(size: 12)
-                Spacer()
-            }
-            Button(Strings.dismissError) { manager.clearError() }
-                .bitchatFont(size: 12)
-                .buttonStyle(.plain)
-        }
-        .padding(.vertical, 6)
-    }
-
-    private var inputSection: some View {
-        HStack(alignment: .top, spacing: 10) {
-            TextField(Strings.addPlaceholder, text: $draft, axis: .vertical)
-                .textFieldStyle(.plain)
-                .bitchatFont(size: 14)
-                .lineLimit(maxDraftLines, reservesSpace: true)
-                .padding(.vertical, 6)
-            Button(action: send) {
-                Image(systemName: "arrow.up.circle.fill")
-                    .font(.bitchatSystem(size: 20))
-                    .foregroundColor(sendButtonEnabled ? accentGreen : .secondary)
-            }
-            .padding(.top, 2)
-            .buttonStyle(.plain)
-            .disabled(!sendButtonEnabled)
-        }
-        .padding(.horizontal, 16)
-        .padding(.vertical, 14)
-        .themedSurface()
-        .overlay(Divider(), alignment: .top)
-    }
-
-    private func send() {
-        guard let content = draft.trimmedOrNilIfEmpty else { return }
-        manager.send(content: content, nickname: senderNickname)
-        draft = ""
-    }
-
-    private var sendButtonEnabled: Bool {
-        !draft.trimmed.isEmpty && manager.state != .noRelays
-    }
-
-    // MARK: - Timestamp Formatting
-    private func timestampText(for date: Date) -> String {
-        let now = Date()
-        if let days = Calendar.current.dateComponents([.day], from: date, to: now).day, days < 7 {
-            let rel = Self.relativeFormatter.string(from: date, to: now) ?? ""
-            return rel.isEmpty ? "" : "\(rel) ago"
-        } else {
-            let sameYear = Calendar.current.isDate(date, equalTo: now, toGranularity: .year)
-            let fmt = sameYear ? Self.absDateFormatter : Self.absDateYearFormatter
-            return fmt.string(from: date)
-        }
-    }
-
-    private static let relativeFormatter: DateComponentsFormatter = {
-        let f = DateComponentsFormatter()
-        f.allowedUnits = [.day, .hour, .minute]
-        f.maximumUnitCount = 1
-        f.unitsStyle = .abbreviated
-        f.collapsesLargestUnit = true
-        return f
-    }()
-
-    private static let absDateFormatter: DateFormatter = {
-        let f = DateFormatter()
-        f.setLocalizedDateFormatFromTemplate("MMM d")
-        return f
-    }()
-
-    private static let absDateYearFormatter: DateFormatter = {
-        let f = DateFormatter()
-        f.setLocalizedDateFormatFromTemplate("MMM d, y")
-        return f
-    }()
-}

bitchat/Views/MeshPeerList.swift

@@ -25,6 +25,8 @@ struct MeshPeerList: View {
         static let favorite = String(localized: "mesh_peers.state.favorite", comment: "State label for a favorited peer")
         static let unread = String(localized: "mesh_peers.state.unread", comment: "State label for a peer with unread private messages")
         static let blocked = String(localized: "mesh_peers.state.blocked", comment: "State label for a blocked peer")
+        static let vouched = String(localized: "mesh_peers.state.vouched", comment: "State label for a peer vouched for by someone the user verified")
+        static let vouchedTooltip = String(localized: "mesh_peers.tooltip.vouched", comment: "Tooltip for the vouched (unfilled seal) badge next to a peer")
         static let addFavorite = String(localized: "content.accessibility.add_favorite", comment: "Accessibility label to add a favorite")
         static let removeFavorite = String(localized: "content.accessibility.remove_favorite", comment: "Accessibility label to remove a favorite")
         static let showFingerprint = String(localized: "mesh_peers.action.fingerprint", comment: "Context menu action that shows a peer's fingerprint/verification screen")
@@ -134,6 +136,16 @@ struct MeshPeerList: View {
                                         .foregroundColor(baseColor)
                                 }
                             }
+
+                            // Vouched (transitively verified): unfilled seal,
+                            // deliberately distinct from verified's filled one.
+                            // Never shown alongside a verified badge.
+                            if peer.showsVouchedBadge {
+                                Image(systemName: "checkmark.seal")
+                                    .font(.bitchatSystem(size: 10))
+                                    .foregroundColor(baseColor)
+                                    .help(Strings.vouchedTooltip)
+                            }
                         }
 
                         Spacer()
@@ -241,6 +253,7 @@ struct MeshPeerList: View {
                 parts.append(Strings.offline)
             }
         }
+        if peer.showsVouchedBadge { parts.append(Strings.vouched) }
         if peer.isFavorite { parts.append(Strings.favorite) }
         if peer.hasUnread { parts.append(Strings.unread) }
         if peer.isBlocked { parts.append(Strings.blocked) }

bitchat/Views/MeshTopologyView.swift

@@ -0,0 +1,217 @@
+//
+// MeshTopologyView.swift
+// bitchat
+//
+// This is free and unencumbered software released into the public domain.
+// For more information, see <https://unlicense.org>
+//
+
+import SwiftUI
+
+/// Display model for the mesh topology map: nodes are known mesh peers,
+/// edges are gossiped `directNeighbors` claims. Built on the main actor from
+/// a `MeshTopologySnapshot` plus the current nickname table.
+struct MeshTopologyDisplayModel {
+    struct Node: Identifiable, Equatable {
+        let id: String
+        let label: String
+        let isSelf: Bool
+    }
+
+    let nodes: [Node]
+    /// Pairs of `Node.id`; every id is present in `nodes`.
+    let edges: [(String, String)]
+
+    static let empty = MeshTopologyDisplayModel(nodes: [], edges: [])
+}
+
+/// Minimal diagnostics sheet: the mesh graph on a circular layout (self in
+/// the center), drawn with Canvas so it stays cheap at any peer count.
+struct MeshTopologyView: View {
+    @Environment(\.dismiss) private var dismiss
+    @Environment(\.appTheme) private var appTheme
+    @ThemedPalette private var palette
+
+    /// Fetches a fresh model; called on appear and on manual refresh.
+    let provider: @MainActor () -> MeshTopologyDisplayModel
+    @State private var model: MeshTopologyDisplayModel = .empty
+
+    var body: some View {
+        #if os(macOS)
+        VStack(spacing: 0) {
+            HStack {
+                Text("topology.title")
+                    .bitchatFont(size: 16, weight: .bold)
+                    .foregroundColor(palette.primary)
+                Spacer()
+                refreshButton
+                Button("app_info.done") {
+                    dismiss()
+                }
+                .buttonStyle(.plain)
+                .foregroundColor(palette.primary)
+            }
+            .padding()
+            .themedSurface(opacity: 0.95)
+
+            content
+        }
+        .frame(width: 500, height: 520)
+        .themedSheetBackground()
+        #else
+        NavigationView {
+            content
+                .themedSheetBackground()
+                .navigationTitle(Text("topology.title"))
+                .navigationBarTitleDisplayMode(.inline)
+                .toolbar {
+                    ToolbarItem(placement: .navigationBarLeading) {
+                        refreshButton
+                    }
+                    ToolbarItem(placement: .navigationBarTrailing) {
+                        SheetCloseButton { dismiss() }
+                            .foregroundColor(palette.primary)
+                    }
+                }
+        }
+        #endif
+    }
+
+    private var refreshButton: some View {
+        Button {
+            model = provider()
+        } label: {
+            Image(systemName: "arrow.clockwise")
+                .font(.bitchatSystem(size: 14))
+                .foregroundColor(palette.primary)
+        }
+        .buttonStyle(.plain)
+        .accessibilityLabel(Text("topology.refresh"))
+    }
+
+    @ViewBuilder
+    private var content: some View {
+        VStack(spacing: 12) {
+            if model.nodes.count <= 1 {
+                Spacer()
+                Text("topology.empty")
+                    .bitchatFont(size: 14)
+                    .foregroundColor(palette.secondary)
+                    .multilineTextAlignment(.center)
+                    .padding(.horizontal, 32)
+                Spacer()
+            } else {
+                graphCanvas
+                    .padding(.horizontal, 8)
+            }
+
+            VStack(spacing: 4) {
+                Text(summaryText)
+                    .bitchatFont(size: 13, weight: .semibold)
+                    .foregroundColor(palette.primary)
+                Text("topology.caption")
+                    .bitchatFont(size: 11)
+                    .foregroundColor(palette.secondary)
+                    .multilineTextAlignment(.center)
+            }
+            .padding(.horizontal)
+            .padding(.bottom, 16)
+        }
+        .onAppear { model = provider() }
+        .accessibilityElement(children: .combine)
+        .accessibilityLabel(Text(summaryText))
+    }
+
+    private var summaryText: String {
+        String(
+            format: String(
+                localized: "topology.summary",
+                comment: "Topology map summary: number of peers and links"
+            ),
+            locale: .current,
+            model.nodes.count,
+            model.edges.count
+        )
+    }
+
+    private var graphCanvas: some View {
+        Canvas { context, size in
+            let positions = Self.layout(nodes: model.nodes, in: size)
+            let fontDesign = appTheme.bodyFontDesign
+
+            // Edges first so nodes draw on top.
+            for (fromID, toID) in model.edges {
+                guard let from = positions[fromID], let to = positions[toID] else { continue }
+                var path = Path()
+                path.move(to: from)
+                path.addLine(to: to)
+                context.stroke(path, with: .color(palette.secondary.opacity(0.45)), lineWidth: 1)
+            }
+
+            for node in model.nodes {
+                guard let center = positions[node.id] else { continue }
+                let radius: CGFloat = node.isSelf ? 7 : 5
+                let dot = Path(ellipseIn: CGRect(
+                    x: center.x - radius,
+                    y: center.y - radius,
+                    width: radius * 2,
+                    height: radius * 2
+                ))
+                context.fill(dot, with: .color(node.isSelf ? palette.accent : palette.primary))
+                if node.isSelf {
+                    let ring = Path(ellipseIn: CGRect(
+                        x: center.x - radius - 3,
+                        y: center.y - radius - 3,
+                        width: (radius + 3) * 2,
+                        height: (radius + 3) * 2
+                    ))
+                    context.stroke(ring, with: .color(palette.accent.opacity(0.6)), lineWidth: 1)
+                }
+                context.draw(
+                    Text(node.label)
+                        .font(.system(size: 10, design: fontDesign))
+                        .foregroundColor(node.isSelf ? palette.accent : palette.secondary),
+                    at: CGPoint(x: center.x, y: center.y + radius + 4),
+                    anchor: .top
+                )
+            }
+        }
+        .accessibilityHidden(true) // The combined summary label narrates the graph.
+    }
+
+    /// Circular layout: self in the center, everyone else evenly spaced on a
+    /// ring. Deterministic (nodes arrive sorted), so refreshes don't shuffle.
+    static func layout(nodes: [MeshTopologyDisplayModel.Node], in size: CGSize) -> [String: CGPoint] {
+        let center = CGPoint(x: size.width / 2, y: size.height / 2)
+        // Leave room for the label row under each ring node.
+        let radius = max(20, min(size.width, size.height) / 2 - 36)
+        var positions: [String: CGPoint] = [:]
+
+        let ringNodes = nodes.filter { !$0.isSelf }
+        for node in nodes where node.isSelf {
+            positions[node.id] = center
+        }
+        for (index, node) in ringNodes.enumerated() {
+            let angle = (2 * CGFloat.pi * CGFloat(index)) / CGFloat(max(1, ringNodes.count)) - CGFloat.pi / 2
+            positions[node.id] = CGPoint(
+                x: center.x + radius * cos(angle),
+                y: center.y + radius * sin(angle)
+            )
+        }
+        return positions
+    }
+}
+
+#Preview("Topology") {
+    MeshTopologyView(provider: {
+        MeshTopologyDisplayModel(
+            nodes: [
+                .init(id: "self", label: "me", isSelf: true),
+                .init(id: "a", label: "alice", isSelf: false),
+                .init(id: "b", label: "bob", isSelf: false),
+                .init(id: "c", label: "carol", isSelf: false)
+            ],
+            edges: [("self", "a"), ("a", "b"), ("self", "c")]
+        )
+    })
+}

bitchat/Views/MessageTextHelpers.swift

@@ -21,17 +21,20 @@ extension String {
         return current >= threshold
     }
 
-    // Extract up to `max` Cashu tokens (cashuA/cashuB). Allow dot '.' and shorter lengths.
+    // Extract up to `max` distinct Cashu tokens (cashuA/cashuB), as the bare
+    // bearer strings. Allow dot '.' and shorter lengths. The `cashu:` URI
+    // form matches too — the token embedded after the scheme is the match.
     func extractCashuLinks(max: Int = 3) -> [String] {
         let regex = MessageFormattingEngine.Patterns.cashu
         let ns = self as NSString
         let range = NSRange(location: 0, length: ns.length)
         var found: [String] = []
-        for m in regex.matches(in: self, range: range) {
-            if m.numberOfRanges > 0 {
-                let token = ns.substring(with: m.range(at: 0))
-                let enc = token.addingPercentEncoding(withAllowedCharacters: .alphanumerics.union(CharacterSet(charactersIn: "-_"))) ?? token
-                found.append("cashu:\(enc)")
+        for m in regex.matches(in: self, range: range) where m.numberOfRanges > 0 {
+            let token = ns.substring(with: m.range(at: 0))
+            // Dedup: repeated tokens are one bearer instrument (and duplicate
+            // ForEach IDs) — one chip is enough.
+            if !found.contains(token) {
+                found.append(token)
                 if found.count >= max { break }
             }
         }

bitchat/Views/NoticesView.swift

@@ -0,0 +1,560 @@
+//
+// NoticesView.swift
+// bitchat
+//
+// This is free and unencumbered software released into the public domain.
+// For more information, see <https://unlicense.org>
+//
+
+import SwiftUI
+
+/// The unified notices sheet behind the header's pin icon: one place for
+/// everything pinned around you, with a scope toggle.
+///
+/// - geo: the current geohash's notices — mesh-synced board posts merged and
+///   deduped with Nostr kind-1 location notes, so you also see notices from
+///   people who aren't on your mesh.
+/// - mesh: the mesh-local board only (empty geohash, fully offline).
+struct NoticesView: View {
+    enum Tab: Hashable {
+        case geo
+        case mesh
+    }
+
+    let senderNickname: String
+    @ObservedObject var board: BoardManager
+
+    @ThemedPalette private var palette
+    @Environment(\.dynamicTypeSize) private var dynamicTypeSize
+    @Environment(\.dismiss) private var dismiss
+    @EnvironmentObject private var locationChannelsModel: LocationChannelsModel
+    @State private var tab: Tab
+    @State private var draft: String = ""
+    @State private var urgent = false
+    @State private var expiryDays = 7
+
+    /// Injected notes manager for tests; live use derives one per geohash.
+    private let notesManager: LocationNotesManager?
+
+    init(
+        senderNickname: String,
+        board: BoardManager,
+        initialTab: Tab,
+        notesManager: LocationNotesManager? = nil
+    ) {
+        self.senderNickname = senderNickname
+        self.board = board
+        self.notesManager = notesManager
+        _tab = State(initialValue: initialTab)
+    }
+
+    private var maxDraftLines: Int { dynamicTypeSize.isAccessibilitySize ? 5 : 3 }
+
+    /// The geohash the geo tab is scoped to: the selected location channel,
+    /// or the device's building geohash when chatting on mesh.
+    private var geoGeohash: String? {
+        if case .location(let channel) = locationChannelsModel.selectedChannel {
+            return channel.geohash
+        }
+        return locationChannelsModel.currentBuildingGeohash
+    }
+
+    /// The geo scope comes from device location only when no location channel
+    /// is selected; that's the case that needs the location machinery.
+    private var geoTabNeedsDeviceLocation: Bool {
+        if case .location = locationChannelsModel.selectedChannel { return false }
+        return true
+    }
+
+    private var activeGeohash: String? {
+        switch tab {
+        case .geo: return geoGeohash
+        case .mesh: return ""
+        }
+    }
+
+    enum Strings {
+        static let title = String(localized: "notices.title", defaultValue: "notices", comment: "Title prefix of the unified notices sheet")
+        static let geoTab = String(localized: "notices.tab.geo", defaultValue: "geo", comment: "Segmented control label for geohash-scoped notices")
+        static let meshTab = String(localized: "notices.tab.mesh", defaultValue: "mesh", comment: "Segmented control label for mesh-local notices")
+        static let scopePicker = String(localized: "notices.accessibility.scope", defaultValue: "Notices scope", comment: "Accessibility label for the geo/mesh scope toggle")
+        // The pre-merge location-notes explainer, reused so its existing
+        // translations carry over.
+        static let geoDescription = String(localized: "location_notes.description", comment: "Explainer for the geo tab of the notices sheet")
+        static let meshDescription = String(localized: "notices.description.mesh", defaultValue: "pin short notices for people around you. they hop phone to phone, even offline, and disappear on their own after a few days.", comment: "Explainer for the mesh tab of the notices sheet")
+        static let emptyTitle = String(localized: "board.empty_title", defaultValue: "no notices yet", comment: "Title shown when the board has no posts")
+        static let emptySubtitle = String(localized: "board.empty_subtitle", defaultValue: "pin the first notice for people around here.", comment: "Subtitle shown when the board has no posts")
+        static let urgentBadge = String(localized: "board.urgent_badge", defaultValue: "urgent", comment: "Badge shown on urgent board posts")
+        static let urgentToggle = String(localized: "board.compose.urgent", defaultValue: "urgent", comment: "Label for the urgent toggle in the board composer")
+        static let placeholder = String(localized: "board.compose.placeholder", defaultValue: "post a notice…", comment: "Placeholder for the board composer text field")
+        static let send = String(localized: "board.accessibility.post", defaultValue: "Post notice", comment: "Accessibility label for the board post button")
+        static let deleteAction = String(localized: "board.action.delete", defaultValue: "delete", comment: "Delete action for own board posts")
+        static let expiryLabel = String(localized: "board.compose.expiry", defaultValue: "expires in", comment: "Label for the board post expiry picker")
+        static let closeHint = String(localized: "notices.accessibility.close", defaultValue: "Close notices", comment: "Accessibility label for the notices close button")
+        static let meshSource = String(localized: "notices.source.mesh", defaultValue: "mesh", comment: "Source badge for notices carried by the mesh")
+        static let nostrSource = String(localized: "notices.source.nostr", defaultValue: "net", comment: "Source badge for notices seen on internet relays")
+        static let locationUnavailable = String(localized: "content.notes.location_unavailable", comment: "Shown when the device location is unavailable for geo notices")
+        static let enableLocation = String(localized: "content.location.enable", comment: "Button enabling location for geo notices")
+        static let loadingNotes: LocalizedStringKey = "location_notes.loading_notes"
+        static let noRelaysNearby: LocalizedStringKey = "location_notes.no_relays_nearby"
+        static let relaysRetryHint: LocalizedStringKey = "location_notes.relays_retry_hint"
+        static let retry: LocalizedStringKey = "location_notes.action.retry"
+        static let dismissError: LocalizedStringKey = "location_notes.action.dismiss"
+
+        static func expiryDaysOption(_ days: Int) -> String {
+            String(
+                format: String(localized: "board.compose.expiry_days", defaultValue: "%lldd", comment: "Expiry picker option, number of days abbreviated"),
+                locale: .current,
+                days
+            )
+        }
+
+        static func rowAccessibilityLabel(author: String, content: String, urgent: Bool) -> String {
+            let base = String(
+                format: String(localized: "board.accessibility.post_row", defaultValue: "Notice from %@: %@", comment: "Accessibility label for a board post row"),
+                locale: .current,
+                author, content
+            )
+            return urgent ? "\(urgentBadge), \(base)" : base
+        }
+    }
+
+    var body: some View {
+        VStack(spacing: 0) {
+            headerSection
+            contentSection
+            if activeGeohash != nil {
+                composer
+            }
+        }
+        .themedSurface()
+        #if os(macOS)
+        .frame(minWidth: 420, idealWidth: 440, minHeight: 620, idealHeight: 680)
+        #endif
+        .themedSheetBackground()
+        .onAppear { beginGeoLocationIfNeeded() }
+        .onChange(of: tab) { newTab in
+            if newTab == .geo {
+                beginGeoLocationIfNeeded()
+            } else {
+                locationChannelsModel.endLiveRefresh()
+            }
+        }
+        // Catches permission granted from the geo tab's enable button.
+        .onChange(of: locationChannelsModel.permissionState) { _ in
+            beginGeoLocationIfNeeded()
+        }
+        .onDisappear { locationChannelsModel.endLiveRefresh() }
+    }
+
+    /// The geo tab tracks the device's building geohash while on mesh; keep
+    /// location fresh only in that case (a selected location channel already
+    /// fixes the scope).
+    private func beginGeoLocationIfNeeded() {
+        guard tab == .geo, geoTabNeedsDeviceLocation,
+              locationChannelsModel.permissionState == .authorized else { return }
+        locationChannelsModel.enableLocationChannels()
+        locationChannelsModel.beginLiveRefresh()
+    }
+
+    private var headerSection: some View {
+        VStack(alignment: .leading, spacing: 8) {
+            HStack(spacing: 12) {
+                Text(verbatim: scopeTitle)
+                    .bitchatFont(size: 18)
+                Spacer()
+                SheetCloseButton { dismiss() }
+                    .accessibilityLabel(Strings.closeHint)
+            }
+            Picker(Strings.scopePicker, selection: $tab) {
+                Text(Strings.geoTab).tag(Tab.geo)
+                Text(Strings.meshTab).tag(Tab.mesh)
+            }
+            .pickerStyle(.segmented)
+            .accessibilityLabel(Strings.scopePicker)
+            Text(tab == .geo ? Strings.geoDescription : Strings.meshDescription)
+                .bitchatFont(size: 12)
+                .foregroundColor(palette.secondary)
+                .fixedSize(horizontal: false, vertical: true)
+        }
+        .padding(.horizontal, 16)
+        .padding(.top, 16)
+        .padding(.bottom, 12)
+        .themedSurface()
+    }
+
+    private var scopeTitle: String {
+        switch tab {
+        case .mesh:
+            return "\(Strings.title) @ #mesh"
+        case .geo:
+            if let geohash = geoGeohash {
+                return "\(Strings.title) @ #\(geohash)"
+            }
+            return Strings.title
+        }
+    }
+
+    @ViewBuilder
+    private var contentSection: some View {
+        switch tab {
+        case .mesh:
+            NoticesList(
+                items: UnifiedNotices.merge(posts: board.posts(forGeohash: ""), notes: []),
+                showsSource: false,
+                board: board,
+                notesManager: nil
+            )
+        case .geo:
+            if let geohash = geoGeohash {
+                GeoNoticesList(geohash: geohash, board: board, manager: notesManager)
+            } else {
+                locationUnavailableSection
+            }
+        }
+    }
+
+    private var locationUnavailableSection: some View {
+        ScrollView {
+            VStack(alignment: .leading, spacing: 12) {
+                Text(Strings.locationUnavailable)
+                    .bitchatFont(size: 14)
+                    .foregroundColor(palette.secondary)
+                    .fixedSize(horizontal: false, vertical: true)
+                Button(Strings.enableLocation) {
+                    locationChannelsModel.enableAndRefresh()
+                }
+                .buttonStyle(.bordered)
+            }
+            .frame(maxWidth: .infinity, alignment: .leading)
+            .padding(.horizontal, 16)
+            .padding(.vertical, 12)
+        }
+        .frame(maxWidth: .infinity, maxHeight: .infinity)
+        .themedSurface()
+    }
+
+    private var composer: some View {
+        VStack(alignment: .leading, spacing: 8) {
+            HStack(alignment: .top, spacing: 10) {
+                TextField(Strings.placeholder, text: $draft, axis: .vertical)
+                    .textFieldStyle(.plain)
+                    .bitchatFont(size: 14)
+                    .lineLimit(maxDraftLines, reservesSpace: true)
+                    .padding(.vertical, 6)
+                Button(action: send) {
+                    Image(systemName: "arrow.up.circle.fill")
+                        .font(.bitchatSystem(size: 20))
+                        .foregroundColor(sendEnabled ? palette.accent : .secondary)
+                }
+                .padding(.top, 2)
+                .buttonStyle(.plain)
+                .disabled(!sendEnabled)
+                .accessibilityLabel(Strings.send)
+            }
+            // Urgency and expiry only travel with the mesh copy — the bridged
+            // Nostr note carries neither, so relay-side readers would never
+            // see them. Offer the controls only where they fully apply.
+            if tab == .mesh {
+                HStack(spacing: 12) {
+                    Toggle(isOn: $urgent) {
+                        Text(Strings.urgentToggle)
+                            .bitchatFont(size: 12)
+                            .foregroundColor(urgent ? palette.alertRed : palette.secondary)
+                    }
+                    .toggleStyle(.switch)
+                    .fixedSize()
+                    .accessibilityLabel(Strings.urgentToggle)
+                    Spacer()
+                    Text(Strings.expiryLabel)
+                        .bitchatFont(size: 12)
+                        .foregroundColor(palette.secondary)
+                    Picker(Strings.expiryLabel, selection: $expiryDays) {
+                        ForEach([1, 3, 7], id: \.self) { days in
+                            Text(Strings.expiryDaysOption(days)).tag(days)
+                        }
+                    }
+                    .pickerStyle(.segmented)
+                    .fixedSize()
+                    .accessibilityLabel(Strings.expiryLabel)
+                }
+            }
+        }
+        .padding(.horizontal, 16)
+        .padding(.vertical, 14)
+        .themedSurface()
+        .overlay(Divider(), alignment: .top)
+    }
+
+    private var sendEnabled: Bool {
+        let trimmed = draft.trimmed
+        return !trimmed.isEmpty && trimmed.utf8.count <= BoardWireConstants.contentMaxBytes
+    }
+
+    private func send() {
+        guard let geohash = activeGeohash, let content = draft.trimmedOrNilIfEmpty else { return }
+        // Geo posts go to the board and are bridged to Nostr by BoardManager,
+        // so mesh and internet see the same notice. They always use the
+        // defaults: non-urgent, 7-day expiry (NIP-40 on the bridged copy).
+        let sent = board.createPost(
+            content: content,
+            geohash: geohash,
+            urgent: tab == .mesh && urgent,
+            expiryDays: tab == .mesh ? expiryDays : 7,
+            nickname: senderNickname
+        )
+        if sent {
+            draft = ""
+            urgent = false
+        }
+    }
+}
+
+/// The geo tab's list: owns the Nostr notes subscription for the scope
+/// geohash and merges it with the board posts for the same geohash.
+private struct GeoNoticesList: View {
+    let geohash: String
+    @ObservedObject var board: BoardManager
+    @StateObject private var notesManager: LocationNotesManager
+
+    init(geohash: String, board: BoardManager, manager: LocationNotesManager? = nil) {
+        let gh = geohash.lowercased()
+        self.geohash = gh
+        self.board = board
+        _notesManager = StateObject(wrappedValue: manager ?? LocationNotesManager(geohash: gh))
+    }
+
+    var body: some View {
+        NoticesList(
+            items: UnifiedNotices.merge(
+                posts: board.posts(forGeohash: geohash),
+                notes: notesManager.notes
+            ),
+            showsSource: true,
+            board: board,
+            notesManager: notesManager
+        )
+        .onChange(of: geohash) { newValue in
+            notesManager.setGeohash(newValue)
+        }
+        .onDisappear { notesManager.cancel() }
+    }
+}
+
+/// Renders merged notices with per-source affordances: swipe-delete for own
+/// items and a mesh/net badge when sources mix.
+private struct NoticesList: View {
+    let items: [NoticeItem]
+    let showsSource: Bool
+    let board: BoardManager
+    let notesManager: LocationNotesManager?
+
+    @ThemedPalette private var palette
+
+    private typealias Strings = NoticesView.Strings
+
+    var body: some View {
+        Group {
+            if items.isEmpty {
+                ScrollView {
+                    VStack(alignment: .leading, spacing: 4) {
+                        statusRows
+                        if showEmptyState {
+                            Text(Strings.emptyTitle)
+                                .bitchatFont(size: 13, weight: .semibold)
+                            Text(Strings.emptySubtitle)
+                                .bitchatFont(size: 12)
+                                .foregroundColor(palette.secondary)
+                        }
+                    }
+                    .frame(maxWidth: .infinity, alignment: .leading)
+                    .padding(.horizontal, 16)
+                    .padding(.vertical, 12)
+                }
+            } else {
+                List {
+                    statusRows
+                        .listRowBackground(palette.background)
+                        .listRowSeparatorTint(palette.divider)
+                    ForEach(items) { item in
+                        row(item)
+                            .listRowBackground(palette.background)
+                            .listRowSeparatorTint(palette.divider)
+                    }
+                }
+                .listStyle(.plain)
+                .scrollContentBackground(.hidden)
+            }
+        }
+        .frame(maxWidth: .infinity, maxHeight: .infinity)
+        .themedSurface()
+    }
+
+    /// Notes may still be loading or unreachable; only claim "no notices yet"
+    /// once the sources settled.
+    private var showEmptyState: Bool {
+        guard let notesManager else { return true }
+        return notesManager.initialLoadComplete && notesManager.state != .loading
+    }
+
+    @ViewBuilder
+    private var statusRows: some View {
+        if let notesManager {
+            if notesManager.state == .loading && !notesManager.initialLoadComplete {
+                HStack(spacing: 10) {
+                    ProgressView()
+                    Text(Strings.loadingNotes)
+                        .bitchatFont(size: 12)
+                        .foregroundColor(palette.secondary)
+                    Spacer()
+                }
+                .padding(.vertical, 8)
+            } else if notesManager.state == .noRelays {
+                VStack(alignment: .leading, spacing: 4) {
+                    Text(Strings.noRelaysNearby)
+                        .bitchatFont(size: 13, weight: .semibold)
+                    Text(Strings.relaysRetryHint)
+                        .bitchatFont(size: 12)
+                        .foregroundColor(palette.secondary)
+                    Button(Strings.retry) { notesManager.refresh() }
+                        .bitchatFont(size: 12)
+                        .buttonStyle(.plain)
+                }
+                .padding(.bottom, 8)
+            } else if let error = notesManager.errorMessage {
+                VStack(alignment: .leading, spacing: 4) {
+                    HStack(spacing: 6) {
+                        Image(systemName: "exclamationmark.triangle.fill")
+                            .bitchatFont(size: 12)
+                        Text(error)
+                            .bitchatFont(size: 12)
+                        Spacer()
+                    }
+                    Button(Strings.dismissError) { notesManager.clearError() }
+                        .bitchatFont(size: 12)
+                        .buttonStyle(.plain)
+                }
+                .padding(.bottom, 8)
+            }
+        }
+    }
+
+    private func canDelete(_ item: NoticeItem) -> Bool {
+        switch item.source {
+        case .board(let post):
+            return board.isOwnPost(post)
+        case .nostr(let note):
+            return notesManager?.isOwnNote(note) ?? false
+        }
+    }
+
+    private func delete(_ item: NoticeItem) {
+        switch item.source {
+        case .board(let post):
+            // Tombstones the board post and retracts the bridged Nostr copy.
+            board.deletePost(post)
+        case .nostr(let note):
+            notesManager?.delete(note: note)
+        }
+    }
+
+    private func row(_ item: NoticeItem) -> some View {
+        let isOwn = canDelete(item)
+        return VStack(alignment: .leading, spacing: 2) {
+            HStack(spacing: 6) {
+                if item.isUrgent {
+                    Image(systemName: "exclamationmark.triangle.fill")
+                        .font(.bitchatSystem(size: 11))
+                        .foregroundColor(palette.alertRed)
+                    Text(Strings.urgentBadge)
+                        .bitchatFont(size: 11, weight: .semibold)
+                        .foregroundColor(palette.alertRed)
+                }
+                Text(verbatim: "@\(item.author)")
+                    .bitchatFont(size: 12, weight: .semibold)
+                Text(Self.timestampText(for: item.createdAt))
+                    .bitchatFont(size: 11)
+                    .foregroundColor(palette.secondary)
+                Spacer()
+                if showsSource {
+                    sourceBadge(item)
+                }
+                if isOwn {
+                    Button {
+                        delete(item)
+                    } label: {
+                        Image(systemName: "trash")
+                            .font(.bitchatSystem(size: 12))
+                            .foregroundColor(palette.secondary)
+                    }
+                    .buttonStyle(.plain)
+                    .accessibilityLabel(Strings.deleteAction)
+                }
+            }
+            Text(item.content)
+                .bitchatFont(size: 14)
+                .fixedSize(horizontal: false, vertical: true)
+        }
+        .padding(.vertical, 4)
+        .accessibilityElement(children: .ignore)
+        .accessibilityLabel(Strings.rowAccessibilityLabel(author: item.author, content: item.content, urgent: item.isUrgent))
+        .accessibilityActions {
+            if isOwn {
+                Button(Strings.deleteAction) { delete(item) }
+            }
+        }
+        .swipeActions(edge: .trailing, allowsFullSwipe: false) {
+            if isOwn {
+                Button(role: .destructive) {
+                    delete(item)
+                } label: {
+                    Label(Strings.deleteAction, systemImage: "trash")
+                }
+            }
+        }
+    }
+
+    private func sourceBadge(_ item: NoticeItem) -> some View {
+        HStack(spacing: 3) {
+            Image(systemName: item.isBoardPost ? "antenna.radiowaves.left.and.right" : "globe")
+                .font(.bitchatSystem(size: 10))
+            Text(item.isBoardPost ? Strings.meshSource : Strings.nostrSource)
+                .bitchatFont(size: 10)
+        }
+        .foregroundColor(palette.secondary.opacity(0.8))
+        .accessibilityLabel(item.isBoardPost ? Strings.meshSource : Strings.nostrSource)
+    }
+
+    // MARK: - Timestamp Formatting
+
+    private static func timestampText(for date: Date) -> String {
+        let now = Date()
+        if let days = Calendar.current.dateComponents([.day], from: date, to: now).day, days < 7 {
+            let rel = relativeFormatter.string(from: date, to: now) ?? ""
+            return rel.isEmpty ? "" : "\(rel) ago"
+        }
+        let sameYear = Calendar.current.isDate(date, equalTo: now, toGranularity: .year)
+        return (sameYear ? absDateFormatter : absDateYearFormatter).string(from: date)
+    }
+
+    private static let relativeFormatter: DateComponentsFormatter = {
+        let f = DateComponentsFormatter()
+        f.allowedUnits = [.day, .hour, .minute]
+        f.maximumUnitCount = 1
+        f.unitsStyle = .abbreviated
+        f.collapsesLargestUnit = true
+        return f
+    }()
+
+    private static let absDateFormatter: DateFormatter = {
+        let f = DateFormatter()
+        f.setLocalizedDateFormatFromTemplate("MMM d")
+        return f
+    }()
+
+    private static let absDateYearFormatter: DateFormatter = {
+        let f = DateFormatter()
+        f.setLocalizedDateFormatFromTemplate("MMM d, y")
+        return f
+    }()
+}

bitchatTests/AppArchitectureTests.swift

@@ -591,6 +591,45 @@ struct AppArchitectureTests {
         #expect(!verificationModel.isVerified(peerID: peerID))
     }
 
+    @Test("VerificationModel refreshes when peer trust changes (vouch accepted)")
+    @MainActor
+    func verificationModelRefreshesOnPeerTrustChange() async {
+        let viewModel = makeArchitectureViewModel()
+        var privateConversationModel: PrivateConversationModel? = PrivateConversationModel(
+            chatViewModel: viewModel,
+            conversations: viewModel.conversations,
+            locationChannelsModel: LocationChannelsModel(manager: makeArchitectureLocationManager())
+        )
+        let verificationModel = VerificationModel(
+            chatViewModel: viewModel,
+            privateConversationModel: privateConversationModel!
+        )
+
+        // PrivateConversationModel happens to observe the same notification
+        // and re-assign its published selection, which would ripple into
+        // VerificationModel; release it so this test pins VerificationModel's
+        // own subscription rather than that incidental chain.
+        privateConversationModel = nil
+
+        // The bound @Published sources replay their current values on
+        // subscription; let those initial main-queue emissions settle so the
+        // sink below observes only the trust-change signal.
+        try? await Task.sleep(nanoseconds: 100_000_000)
+
+        // ChatVouchCoordinator.notifyPeerTrustChanged() signals accepted
+        // vouches via "peerStatusUpdated"; an open fingerprint sheet must
+        // re-render its vouched badge from that signal alone.
+        var refreshed = false
+        let cancellable = verificationModel.objectWillChange.sink { _ in
+            refreshed = true
+        }
+        defer { cancellable.cancel() }
+
+        NotificationCenter.default.post(name: Notification.Name("peerStatusUpdated"), object: nil)
+        await waitUntil { refreshed }
+        #expect(refreshed)
+    }
+
     @Test("PeerListModel publishes mesh and geohash directory state")
     @MainActor
     func peerListModelPublishesDirectoryState() async {

bitchatTests/BLEServiceCoreTests.swift

@@ -216,6 +216,69 @@ struct BLEServiceCoreTests {
             cachedServiceUUIDs: [BLEService.serviceUUID, otherService]
         ))
     }
+
+    /// Pings are unsigned, so their claimed sender is attacker-controlled.
+    /// The pong budget must be keyed on the ingress link (the directly
+    /// connected peer that delivered the packet): rotating forged sender IDs
+    /// over one link exhausts one budget instead of resetting it, so a single
+    /// malicious link cannot turn /ping into an amplification primitive.
+    @Test
+    func meshPingResponseBudget_isPerIngressLinkNotClaimedSender() async throws {
+        let ble = makeService()
+        let outbound = OutboundPacketTap()
+        ble._test_onOutboundPacket = outbound.record
+
+        let link = PeerID(str: "1122334455667788")
+        let budget = TransportConfig.meshPingInboundMaxPerLink
+        let myRecipientData = try #require(Data(hexString: ble.myPeerID.id))
+
+        for i in 0..<(budget * 2) {
+            // A fresh forged sender for every ping, all arriving on one link.
+            let forgedSender = PeerID(str: String(format: "%016x", 0xA0_0000 + i))
+            var nonce = Data(repeating: 0, count: MeshPingPayload.nonceLength)
+            nonce[0] = UInt8(i)
+            let payload = try #require(MeshPingPayload(nonce: nonce, originTTL: 7))
+            let packet = BitchatPacket(
+                type: MessageType.ping.rawValue,
+                senderID: Data(hexString: forgedSender.id) ?? Data(),
+                recipientID: myRecipientData,
+                timestamp: UInt64(Date().timeIntervalSince1970 * 1000),
+                payload: payload.encode(),
+                signature: nil,
+                ttl: 7
+            )
+            ble._test_handlePacket(packet, fromPeerID: link, preseedPeer: false)
+        }
+
+        let reachedBudget = await TestHelpers.waitUntil(
+            { outbound.count(ofType: .pong) >= budget },
+            timeout: TestConstants.defaultTimeout
+        )
+        #expect(reachedBudget)
+        // Give any over-budget pong a chance to surface, then confirm the
+        // rotated sender IDs never bought a sixth response.
+        let exceededBudget = await TestHelpers.waitUntil(
+            { outbound.count(ofType: .pong) > budget },
+            timeout: TestConstants.shortTimeout
+        )
+        #expect(!exceededBudget)
+        #expect(outbound.count(ofType: .pong) == budget)
+    }
+}
+
+/// Thread-safe capture of packets leaving the service under test.
+private final class OutboundPacketTap {
+    private let lock = NSLock()
+    private var packets: [BitchatPacket] = []
+
+    func record(_ packet: BitchatPacket) {
+        lock.lock(); packets.append(packet); lock.unlock()
+    }
+
+    func count(ofType type: MessageType) -> Int {
+        lock.lock(); defer { lock.unlock() }
+        return packets.filter { $0.type == type.rawValue }.count
+    }
 }
 
 private func makeService() -> BLEService {

bitchatTests/CashuTokenDecoderTests.swift

@@ -0,0 +1,350 @@
+//
+// CashuTokenDecoderTests.swift
+// bitchatTests
+//
+// Tests for the Cashu token summary decoder: V3 JSON decode, minimal V4
+// CBOR traversal, URI normalization, detection ranges, and adversarial
+// (truncated / garbage / huge) input. The decoder renders attacker-controlled
+// message content, so "never crash" matters as much as "decode correctly".
+// This is free and unencumbered software released into the public domain.
+//
+
+import Foundation
+import Testing
+@testable import bitchat
+
+struct CashuTokenDecoderTests {
+
+    // MARK: - Token Builders
+
+    private func base64URL(_ data: Data) -> String {
+        data.base64EncodedString()
+            .replacingOccurrences(of: "+", with: "-")
+            .replacingOccurrences(of: "/", with: "_")
+            .replacingOccurrences(of: "=", with: "")
+    }
+
+    private func makeV3Token(
+        entries: [(mint: String, amounts: [Int])],
+        unit: String? = "sat",
+        memo: String? = nil
+    ) -> String {
+        var json: [String: Any] = [
+            "token": entries.map { entry in
+                [
+                    "mint": entry.mint,
+                    "proofs": entry.amounts.map {
+                        ["amount": $0, "id": "009a1f293253e41e", "secret": "s", "C": "02c"] as [String: Any]
+                    }
+                ] as [String: Any]
+            }
+        ]
+        if let unit { json["unit"] = unit }
+        if let memo { json["memo"] = memo }
+        let data = try! JSONSerialization.data(withJSONObject: json)
+        return "cashuA" + base64URL(data)
+    }
+
+    /// Tiny deterministic CBOR encoder (definite lengths only) for building
+    /// V4 test tokens without depending on the decoder under test.
+    private enum CBOREncode {
+        static func head(_ major: UInt8, _ value: UInt64) -> [UInt8] {
+            switch value {
+            case 0...23:
+                return [(major << 5) | UInt8(value)]
+            case 24...0xFF:
+                return [(major << 5) | 24, UInt8(value)]
+            case 0x100...0xFFFF:
+                return [(major << 5) | 25, UInt8(value >> 8), UInt8(value & 0xFF)]
+            default:
+                return [(major << 5) | 26,
+                        UInt8((value >> 24) & 0xFF), UInt8((value >> 16) & 0xFF),
+                        UInt8((value >> 8) & 0xFF), UInt8(value & 0xFF)]
+            }
+        }
+        static func uint(_ v: UInt64) -> [UInt8] { head(0, v) }
+        static func bytes(_ b: [UInt8]) -> [UInt8] { head(2, UInt64(b.count)) + b }
+        static func text(_ s: String) -> [UInt8] {
+            let utf8 = Array(s.utf8)
+            return head(3, UInt64(utf8.count)) + utf8
+        }
+        static func array(_ items: [[UInt8]]) -> [UInt8] {
+            head(4, UInt64(items.count)) + items.flatMap { $0 }
+        }
+        static func map(_ pairs: [(String, [UInt8])]) -> [UInt8] {
+            head(5, UInt64(pairs.count)) + pairs.flatMap { text($0.0) + $0.1 }
+        }
+    }
+
+    private func makeV4Token(
+        mint: String = "https://mint.example.com",
+        unit: String = "sat",
+        memo: String? = nil,
+        amounts: [UInt64] = [1, 4]
+    ) -> String {
+        var pairs: [(String, [UInt8])] = [
+            ("m", CBOREncode.text(mint)),
+            ("u", CBOREncode.text(unit))
+        ]
+        if let memo { pairs.append(("d", CBOREncode.text(memo))) }
+        let proofs = amounts.map { amount in
+            CBOREncode.map([
+                ("a", CBOREncode.uint(amount)),
+                ("s", CBOREncode.text("secret")),
+                ("c", CBOREncode.bytes([0x02, 0xAB, 0xCD]))
+            ])
+        }
+        pairs.append(("t", CBOREncode.array([
+            CBOREncode.map([
+                ("i", CBOREncode.bytes([0x00, 0xAD, 0x26, 0x8C])),
+                ("p", CBOREncode.array(proofs))
+            ])
+        ])))
+        return "cashuB" + base64URL(Data(CBOREncode.map(pairs)))
+    }
+
+    // MARK: - V3 Decode
+
+    @Test func v3DecodeValidToken() {
+        let token = makeV3Token(
+            entries: [("https://mint.example.com", [2, 8])],
+            unit: "sat",
+            memo: "thanks!"
+        )
+        let info = CashuTokenDecoder.decode(token)
+        #expect(info != nil)
+        #expect(info?.version == "A")
+        #expect(info?.amount == 10)
+        #expect(info?.unit == "sat")
+        #expect(info?.mintHost == "mint.example.com")
+        #expect(info?.memo == "thanks!")
+        #expect(info?.displayAmount == "10 sat")
+    }
+
+    @Test func v3AmountSumsAcrossEntriesAndProofs() {
+        let token = makeV3Token(entries: [
+            ("https://a.mint.example", [1, 2, 4]),
+            ("https://b.mint.example", [8, 16])
+        ])
+        let info = CashuTokenDecoder.decode(token)
+        #expect(info?.amount == 31)
+        // First mint wins for the display host
+        #expect(info?.mintHost == "a.mint.example")
+    }
+
+    @Test func v3MissingUnitDefaultsToSatForDisplay() {
+        let token = makeV3Token(entries: [("https://mint.example.com", [5])], unit: nil)
+        let info = CashuTokenDecoder.decode(token)
+        #expect(info?.unit == nil)
+        #expect(info?.displayAmount == "5 sat")
+    }
+
+    @Test func v3RejectsNonsenseAmounts() {
+        // Negative and absurd amounts must not poison the sum
+        let json: [String: Any] = [
+            "token": [[
+                "mint": "https://mint.example.com",
+                "proofs": [
+                    ["amount": -5, "id": "x", "secret": "s", "C": "c"],
+                    ["amount": 3, "id": "x", "secret": "s", "C": "c"]
+                ]
+            ] as [String: Any]]
+        ]
+        let token = "cashuA" + base64URL(try! JSONSerialization.data(withJSONObject: json))
+        #expect(CashuTokenDecoder.decode(token)?.amount == 3)
+    }
+
+    @Test func v3MemoIsSanitizedForDisplay() {
+        let token = makeV3Token(
+            entries: [("https://mint.example.com", [1])],
+            memo: "line1\nline2\u{0007}" + String(repeating: "x", count: 300)
+        )
+        let memo = CashuTokenDecoder.decode(token)?.memo
+        #expect(memo != nil)
+        #expect(memo?.contains("\n") == false)
+        #expect(memo?.contains("\u{0007}") == false)
+        #expect((memo?.count ?? 0) <= 80)
+    }
+
+    // MARK: - V4 (CBOR) Decode
+
+    @Test func v4DecodeValidToken() {
+        let token = makeV4Token(memo: "Thank you", amounts: [1, 4, 16])
+        let info = CashuTokenDecoder.decode(token)
+        #expect(info?.version == "B")
+        #expect(info?.amount == 21)
+        #expect(info?.unit == "sat")
+        #expect(info?.mintHost == "mint.example.com")
+        #expect(info?.memo == "Thank you")
+    }
+
+    @Test func v4UnparseableCBORDegradesToGenericToken() {
+        // Valid base64 payload, but not CBOR we can walk: still a token,
+        // rendered as a generic chip with no amount.
+        let token = "cashuB" + base64URL(Data([0xFF, 0xFF, 0xFF, 0xFF, 0x00, 0x01, 0x02]))
+        let info = CashuTokenDecoder.decode(token)
+        #expect(info?.version == "B")
+        #expect(info?.amount == nil)
+        #expect(info?.mintHost == nil)
+    }
+
+    // MARK: - Strict Mode (used by the /pay SEND path)
+
+    @Test func strictAcceptsValidV3WithPositiveAmount() {
+        let token = makeV3Token(entries: [("https://mint.example.com", [2, 8])])
+        let info = CashuTokenDecoder.decode(token, strict: true)
+        #expect(info?.version == "A")
+        #expect(info?.amount == 10)
+    }
+
+    @Test func strictAcceptsValidDefiniteLengthV4() {
+        let token = makeV4Token(amounts: [1, 4, 16])
+        let info = CashuTokenDecoder.decode(token, strict: true)
+        #expect(info?.version == "B")
+        #expect(info?.amount == 21)
+    }
+
+    @Test func strictRejectsUnwalkableV4() {
+        // Valid base64, but not CBOR we can walk: permissive mode returns a
+        // generic chip, strict mode refuses it.
+        let token = "cashuB" + base64URL(Data([0xFF, 0xFF, 0xFF, 0xFF, 0x00, 0x01, 0x02]))
+        #expect(CashuTokenDecoder.decode(token)?.version == "B")
+        #expect(CashuTokenDecoder.decode(token, strict: true) == nil)
+    }
+
+    @Test func strictRejectsTruncatedV4() {
+        let token = makeV4Token(amounts: [1, 4, 16])
+        // Lop off the tail of the base64 payload — CBOR can no longer be walked.
+        let truncated = String(token.prefix(token.count - 12))
+        #expect(CashuTokenDecoder.decode(truncated, strict: true) == nil)
+    }
+
+    @Test func strictRejectsAmountlessToken() {
+        // A well-formed V3 token that carries no positive proof amount.
+        let json: [String: Any] = [
+            "token": [[
+                "mint": "https://mint.example.com",
+                "proofs": [["amount": 0, "id": "x", "secret": "s", "C": "c"] as [String: Any]]
+            ] as [String: Any]]
+        ]
+        let token = "cashuA" + base64URL(try! JSONSerialization.data(withJSONObject: json))
+        #expect(CashuTokenDecoder.decode(token)?.amount == nil)
+        #expect(CashuTokenDecoder.decode(token, strict: true) == nil)
+    }
+
+    // MARK: - URI Form and Normalization
+
+    @Test func uriFormsDecode() {
+        let token = makeV3Token(entries: [("https://mint.example.com", [7])])
+        for wrapped in ["cashu:\(token)", "cashu://\(token)", "CASHU:\(token)"] {
+            #expect(CashuTokenDecoder.bareToken(from: wrapped) == token, "failed for \(wrapped)")
+            #expect(CashuTokenDecoder.decode(wrapped)?.amount == 7)
+        }
+    }
+
+    @Test func percentEncodedURIDecodes() {
+        let token = makeV3Token(entries: [("https://mint.example.com", [7])])
+        let encoded = token.addingPercentEncoding(withAllowedCharacters: .alphanumerics)!
+        #expect(CashuTokenDecoder.decode("cashu:\(encoded)")?.amount == 7)
+    }
+
+    @Test func bareTokenRejectsNonTokens() {
+        #expect(CashuTokenDecoder.bareToken(from: "hello world") == nil)
+        #expect(CashuTokenDecoder.bareToken(from: "cashuC" + String(repeating: "a", count: 50)) == nil)
+        #expect(CashuTokenDecoder.bareToken(from: "cashuA{not-base64!}") == nil)
+        #expect(CashuTokenDecoder.bareToken(from: "cashuA") == nil) // too short
+    }
+
+    // MARK: - Adversarial Input (never crash, fail closed)
+
+    @Test func truncatedTokensNeverCrash() {
+        let v3 = makeV3Token(entries: [("https://mint.example.com", [1, 2, 4, 8])], memo: "memo")
+        let v4 = makeV4Token(memo: "memo", amounts: [1, 2, 4, 8])
+        for token in [v3, v4] {
+            for length in stride(from: 0, to: token.count, by: 3) {
+                _ = CashuTokenDecoder.decode(String(token.prefix(length)))
+            }
+        }
+        // Truncating the payload must not produce a phantom V3 summary
+        #expect(CashuTokenDecoder.decode(String(v3.prefix(v3.count - 10))) == nil)
+    }
+
+    @Test func garbagePayloadsNeverCrash() {
+        var rng = SystemRandomNumberGenerator()
+        for _ in 0..<200 {
+            let length = Int.random(in: 0..<600, using: &rng)
+            let junk = Data((0..<length).map { _ in UInt8.random(in: 0...255, using: &rng) })
+            _ = CashuTokenDecoder.decode("cashuA" + base64URL(junk))
+            _ = CashuTokenDecoder.decode("cashuB" + base64URL(junk))
+        }
+    }
+
+    @Test func hugeInputIsRejectedQuickly() {
+        let huge = "cashuA" + String(repeating: "Q", count: 500_000)
+        #expect(CashuTokenDecoder.bareToken(from: huge) == nil)
+        #expect(CashuTokenDecoder.decode(huge) == nil)
+    }
+
+    @Test func absurdAmountsFailClosed() {
+        // Each proof exceeds the per-proof sanity cap: skipped, no amount.
+        let perProofJSON: [String: Any] = [
+            "token": [[
+                "mint": "https://mint.example.com",
+                "proofs": [["amount": Int64.max / 2, "id": "x", "secret": "s", "C": "c"] as [String: Any]]
+            ] as [String: Any]]
+        ]
+        let perProofToken = "cashuA" + base64URL(try! JSONSerialization.data(withJSONObject: perProofJSON))
+        #expect(CashuTokenDecoder.decode(perProofToken)?.amount == nil)
+
+        // Individually plausible proofs whose *sum* overflows the cap: the
+        // token is nonsense, reject it entirely (never trap on the add).
+        let sumJSON: [String: Any] = [
+            "token": [[
+                "mint": "https://mint.example.com",
+                "proofs": (0..<3).map { _ in
+                    ["amount": 1_500_000_000_000_000, "id": "x", "secret": "s", "C": "c"] as [String: Any]
+                }
+            ] as [String: Any]]
+        ]
+        let sumToken = "cashuA" + base64URL(try! JSONSerialization.data(withJSONObject: sumJSON))
+        #expect(CashuTokenDecoder.decode(sumToken) == nil)
+    }
+
+    @Test func deeplyNestedCBORIsBounded() {
+        // 64 nested single-element arrays around an int: deeper than the
+        // reader's depth cap, must fail cleanly.
+        var payload = CBOREncode.uint(1)
+        for _ in 0..<64 { payload = CBOREncode.array([payload]) }
+        let token = "cashuB" + base64URL(Data(payload))
+        let info = CashuTokenDecoder.decode(token)
+        #expect(info?.amount == nil)
+    }
+
+    // MARK: - Detection Ranges (message scanning)
+
+    @Test func detectionFindsWholeMessageToken() {
+        let token = makeV3Token(entries: [("https://mint.example.com", [1])])
+        #expect(token.extractCashuLinks() == [token])
+    }
+
+    @Test func detectionFindsEmbeddedAndURITokens() {
+        let token = makeV3Token(entries: [("https://mint.example.com", [1])])
+        let message = "here you go: cashu:\(token) enjoy!"
+        // The regex matches the token embedded after the scheme
+        #expect(message.extractCashuLinks() == [token])
+
+        let embedded = "prefix \(token) suffix"
+        #expect(embedded.extractCashuLinks() == [token])
+    }
+
+    @Test func detectionDeduplicatesRepeatedTokens() {
+        let token = makeV3Token(entries: [("https://mint.example.com", [1])])
+        let message = "\(token) and again \(token)"
+        #expect(message.extractCashuLinks() == [token])
+    }
+
+    @Test func detectionIgnoresNonTokens() {
+        #expect("just talking about cashu here".extractCashuLinks().isEmpty)
+        #expect("cashuAshort".extractCashuLinks().isEmpty)
+    }
+}

bitchatTests/ChatNostrCoordinatorContextTests.swift

@@ -71,6 +71,7 @@ private final class MockChatNostrContext: ChatNostrContext {
     private(set) var hapticMessageIDs: [String] = []
 
     func handlePublicMessage(_ message: BitchatMessage) { handledPublicMessages.append(message) }
+    func handlePublicMessage(_ message: BitchatMessage, powBits: Int) { handledPublicMessages.append(message) }
     func checkForMentions(_ message: BitchatMessage) { mentionCheckedMessageIDs.append(message.id) }
     func sendHapticFeedback(for message: BitchatMessage) { hapticMessageIDs.append(message.id) }
     func parseMentions(from content: String) -> [String] { [] }

bitchatTests/ChatOutgoingCoordinatorContextTests.swift

@@ -192,6 +192,9 @@ struct ChatOutgoingCoordinatorContextTests {
         context.isTeleported = true
 
         coordinator.sendMessage("hello geo")
+        // Geohash sends mine a NIP-13 nonce tag off-main before echoing and
+        // sending; await the send task, then drain the main queue.
+        await coordinator.geohashMiningTask?.value
         await drainMainActorTasks()
 
         // Local echo carries the geohash sender suffix (#last-4-of-pubkey) and
@@ -215,4 +218,35 @@ struct ChatOutgoingCoordinatorContextTests {
         #expect(context.appendedPublicMessages.count == 1)
         #expect(context.sentGeohashContexts.count == 1)
     }
+
+    @Test @MainActor
+    func sendMessage_onLocationChannel_serializesRapidSendsInSendOrder() async {
+        let context = MockChatOutgoingContext()
+        let coordinator = ChatOutgoingCoordinator(context: context)
+        let channel = GeohashChannel(level: .city, geohash: "u4pruydq")
+        context.activeChannel = .location(channel)
+
+        // Two back-to-back sends. The first carries much larger content, so
+        // its NIP-13 mining hashes a bigger event per attempt and runs longer
+        // than the second's. Without serialization the second (faster) task
+        // could finish first and reorder both the local timeline and the
+        // relayed events. The coordinator chains the mining tasks — each send
+        // awaits the previous send's task before it echoes and relays — so the
+        // visible order must always match the send order.
+        let first = "first " + String(repeating: "x", count: 4000)
+        let second = "second"
+        coordinator.sendMessage(first)
+        coordinator.sendMessage(second)
+
+        // The stored task is the second send, which awaits the first.
+        await coordinator.geohashMiningTask?.value
+        await drainMainActorTasks()
+
+        // Local echoes land in send order…
+        #expect(context.appendedPublicMessages.map(\.message.content) == [first, second])
+        // …and so do the relayed events (IDs match the echoes 1:1, in order).
+        #expect(context.sentGeohashContexts.count == 2)
+        #expect(context.sentGeohashContexts.map(\.event.id)
+                == context.appendedPublicMessages.map(\.message.id))
+    }
 }

bitchatTests/ChatPublicConversationCoordinatorContextTests.swift

@@ -186,7 +186,7 @@ private final class MockChatPublicConversationContext: ChatPublicConversationCon
     // Inbound public message processing
     var blockedMessageIDs: Set<String> = []
     var rateLimitAllowed = true
-    private(set) var rateLimitChecks: [(senderKey: String, contentKey: String)] = []
+    private(set) var rateLimitChecks: [(senderKey: String, contentKey: String, powBits: Int)] = []
     private(set) var enqueuedMessages: [(messageID: String, conversationID: ConversationID)] = []
     var enqueuedMessageIDs: [String] { enqueuedMessages.map(\.messageID) }
     var stablePeerIDs: [PeerID: PeerID] = [:]
@@ -199,8 +199,8 @@ private final class MockChatPublicConversationContext: ChatPublicConversationCon
         blockedMessageIDs.contains(message.id)
     }
 
-    func allowPublicMessage(senderKey: String, contentKey: String) -> Bool {
-        rateLimitChecks.append((senderKey, contentKey))
+    func allowPublicMessage(senderKey: String, contentKey: String, powBits: Int) -> Bool {
+        rateLimitChecks.append((senderKey, contentKey, powBits))
         return rateLimitAllowed
     }
 

bitchatTests/ChatTransportEventCoordinatorContextTests.swift

@@ -156,6 +156,24 @@ private final class MockChatTransportEventContext: ChatTransportEventContext {
     func handleVerifyResponsePayload(from peerID: PeerID, payload: Data) {
         verifyResponsePayloads.append((peerID, payload))
     }
+
+    // Group payloads
+    private(set) var groupInvitePayloads: [(peerID: PeerID, payload: Data)] = []
+    private(set) var groupKeyUpdatePayloads: [(peerID: PeerID, payload: Data)] = []
+
+    func handleGroupInvitePayload(from peerID: PeerID, payload: Data) {
+        groupInvitePayloads.append((peerID, payload))
+    }
+
+    func handleGroupKeyUpdatePayload(from peerID: PeerID, payload: Data) {
+        groupKeyUpdatePayloads.append((peerID, payload))
+    }
+
+    private(set) var vouchPayloads: [(peerID: PeerID, payload: Data)] = []
+
+    func handleVouchPayload(from peerID: PeerID, payload: Data) {
+        vouchPayloads.append((peerID, payload))
+    }
 }
 
 // MARK: - Helpers

bitchatTests/ChatVerificationCoordinatorContextTests.swift

@@ -51,6 +51,9 @@ private final class MockChatVerificationContext: ChatVerificationContext {
 
     func saveIdentityState() { saveIdentityStateCount += 1 }
 
+    private(set) var vouchToConnectedVerifiedPeersCount = 0
+    func vouchToConnectedVerifiedPeers() { vouchToConnectedVerifiedPeersCount += 1 }
+
     // Encryption status
     private(set) var encryptionStatuses: [PeerID: EncryptionStatus?] = [:]
     private(set) var updatedEncryptionStatusPeers: [PeerID] = []

bitchatTests/ChatVouchCoordinatorContextTests.swift

@@ -0,0 +1,353 @@
+//
+// ChatVouchCoordinatorContextTests.swift
+// bitchatTests
+//
+// Exercises `ChatVouchCoordinator` against a mock `ChatVouchContext` —
+// proving the exchange policy (verified + capable peers only, batch cap,
+// 24h rate limit) and the accept policy (verified senders only, real
+// Ed25519 signature verification, expiry) without a `ChatViewModel`.
+// Storage-level gates (self-vouch, already-verified vouchee, per-vouchee
+// cap) are covered by `SecureIdentityStateManagerVouchTests`.
+//
+
+import CryptoKit
+import Foundation
+import BitFoundation
+import Testing
+
+@testable import bitchat
+
+// MARK: - Mock Context
+
+@MainActor
+private final class MockChatVouchContext: ChatVouchContext {
+    // Identity & trust state
+    var fingerprintsByPeerID: [PeerID: String] = [:]
+    var verifiedFingerprints: Set<String> = []
+    var signingKeysByFingerprint: [String: Data] = [:]
+    var recentVerified: [String] = []
+    private(set) var recentVerifiedRequests: [(limit: Int, excluding: String)] = []
+    private(set) var recordedVouches: [(vouchee: String, voucher: String, timestamp: Date)] = []
+    var recordVouchResult = true
+    var lastBatchSentAt: [String: Date] = [:]
+    private(set) var markedBatchSent: [(fingerprint: String, date: Date)] = []
+
+    func getFingerprint(for peerID: PeerID) -> String? { fingerprintsByPeerID[peerID] }
+    func isVerifiedFingerprint(_ fingerprint: String) -> Bool { verifiedFingerprints.contains(fingerprint) }
+    func signingKey(forFingerprint fingerprint: String) -> Data? { signingKeysByFingerprint[fingerprint] }
+
+    func recentlyVerifiedFingerprints(limit: Int, excluding fingerprint: String) -> [String] {
+        recentVerifiedRequests.append((limit, fingerprint))
+        return Array(recentVerified.filter { $0 != fingerprint }.prefix(limit))
+    }
+
+    @discardableResult
+    func recordVouch(voucheeFingerprint: String, voucherFingerprint: String, timestamp: Date) -> Bool {
+        recordedVouches.append((voucheeFingerprint, voucherFingerprint, timestamp))
+        return recordVouchResult
+    }
+
+    func lastVouchBatchSent(to fingerprint: String) -> Date? { lastBatchSentAt[fingerprint] }
+
+    func markVouchBatchSent(to fingerprint: String, at date: Date) {
+        markedBatchSent.append((fingerprint, date))
+        lastBatchSentAt[fingerprint] = date
+    }
+
+    // Transport
+    var capabilitiesByPeerID: [PeerID: PeerCapabilities] = [:]
+    var mySigningKey = Curve25519.Signing.PrivateKey()
+    private(set) var installedObservers: [(PeerID, String) -> Void] = []
+    private(set) var sentVouchPayloads: [(payload: Data, peerID: PeerID)] = []
+
+    var connectedPeerIDList: [PeerID] = []
+
+    func peerCapabilities(for peerID: PeerID) -> PeerCapabilities { capabilitiesByPeerID[peerID] ?? [] }
+
+    func connectedPeerIDs() -> [PeerID] { connectedPeerIDList }
+
+    func addPeerAuthenticatedObserver(_ handler: @escaping (PeerID, String) -> Void) {
+        installedObservers.append(handler)
+    }
+
+    func noiseSignData(_ data: Data) -> Data? { try? mySigningKey.signature(for: data) }
+
+    func sendVouchAttestations(_ payload: Data, to peerID: PeerID) {
+        sentVouchPayloads.append((payload, peerID))
+    }
+
+    // UI refresh
+    private(set) var trustChangedCount = 0
+
+    func notifyPeerTrustChanged() { trustChangedCount += 1 }
+}
+
+// MARK: - Tests
+
+struct ChatVouchCoordinatorContextTests {
+    private let peerID = PeerID(str: "1122334455667788")
+    private let peerFingerprint = String(repeating: "0f", count: 32)
+
+    @MainActor
+    private func makeVerifiedCapablePeer() -> (MockChatVouchContext, ChatVouchCoordinator) {
+        let context = MockChatVouchContext()
+        let coordinator = ChatVouchCoordinator(context: context)
+        context.fingerprintsByPeerID[peerID] = peerFingerprint
+        context.verifiedFingerprints.insert(peerFingerprint)
+        context.capabilitiesByPeerID[peerID] = [.vouch]
+        return (context, coordinator)
+    }
+
+    // MARK: Exchange policy
+
+    @Test @MainActor
+    func peerAuthenticated_sendsBatchForVerifiedCapablePeer() throws {
+        let (context, coordinator) = makeVerifiedCapablePeer()
+        let vouchees = [String(repeating: "01", count: 32), String(repeating: "02", count: 32)]
+        context.recentVerified = vouchees
+        for vouchee in vouchees {
+            context.signingKeysByFingerprint[vouchee] = Data(repeating: 0x33, count: 32)
+        }
+
+        coordinator.peerAuthenticated(peerID, fingerprint: peerFingerprint)
+
+        // Candidates are requested most-recent-first, excluding the target.
+        #expect(context.recentVerifiedRequests.count == 1)
+        #expect(context.recentVerifiedRequests.first?.limit == VouchAttestation.maxBatchCount)
+        #expect(context.recentVerifiedRequests.first?.excluding == peerFingerprint)
+
+        let sent = try #require(context.sentVouchPayloads.first)
+        #expect(sent.peerID == peerID)
+        let attestations = VouchAttestation.decodeList(from: sent.payload)
+        #expect(attestations.map(\.voucheeFingerprintHex) == vouchees)
+        // Every attestation carries a valid signature under our signing key.
+        let myPublicKey = context.mySigningKey.publicKey.rawRepresentation
+        #expect(attestations.allSatisfy { $0.verifySignature(voucherSigningKey: myPublicKey) })
+
+        // The rate limit is stamped only after an actual send.
+        #expect(context.markedBatchSent.map(\.fingerprint) == [peerFingerprint])
+    }
+
+    @Test @MainActor
+    func peerAuthenticated_requiresVerificationAndCapability() {
+        let (context, coordinator) = makeVerifiedCapablePeer()
+        context.recentVerified = [String(repeating: "01", count: 32)]
+        context.signingKeysByFingerprint[context.recentVerified[0]] = Data(repeating: 0x33, count: 32)
+
+        // Not verified by me: nothing.
+        context.verifiedFingerprints.remove(peerFingerprint)
+        coordinator.peerAuthenticated(peerID, fingerprint: peerFingerprint)
+        #expect(context.sentVouchPayloads.isEmpty)
+
+        // Verified but advertises a non-empty capability set lacking .vouch:
+        // nothing. (An *empty*/unknown set is race-tolerant and still sends —
+        // see `attemptVouch_sendsWhenCapabilitiesUnknown`.)
+        context.verifiedFingerprints.insert(peerFingerprint)
+        context.capabilitiesByPeerID[peerID] = [.prekeys]
+        coordinator.peerAuthenticated(peerID, fingerprint: peerFingerprint)
+        #expect(context.sentVouchPayloads.isEmpty)
+        #expect(context.markedBatchSent.isEmpty)
+    }
+
+    // MARK: Capability race tolerance & new triggers
+
+    @Test @MainActor
+    func attemptVouch_sendsWhenCapabilitiesUnknown() {
+        // Capability set still empty at attempt time (the peer's .vouch bit
+        // arrives on a later announce): the batch must still go out.
+        let (context, coordinator) = makeVerifiedCapablePeer()
+        context.capabilitiesByPeerID[peerID] = []
+        context.recentVerified = [String(repeating: "01", count: 32)]
+        context.signingKeysByFingerprint[context.recentVerified[0]] = Data(repeating: 0x33, count: 32)
+
+        coordinator.peerAuthenticated(peerID, fingerprint: peerFingerprint)
+        #expect(context.sentVouchPayloads.count == 1)
+        #expect(context.markedBatchSent.map(\.fingerprint) == [peerFingerprint])
+    }
+
+    @Test @MainActor
+    func vouchToConnectedVerifiedPeers_sendsToConnectedVerifiedCapablePeer() {
+        let (context, coordinator) = makeVerifiedCapablePeer()
+        context.connectedPeerIDList = [peerID]
+        context.recentVerified = [String(repeating: "01", count: 32)]
+        context.signingKeysByFingerprint[context.recentVerified[0]] = Data(repeating: 0x33, count: 32)
+
+        // Session is already up (no peerAuthenticated re-fire); the verify pass
+        // is what makes the batch go out.
+        coordinator.vouchToConnectedVerifiedPeers()
+        let sent = context.sentVouchPayloads
+        #expect(sent.count == 1)
+        #expect(sent.first?.peerID == peerID)
+        #expect(context.markedBatchSent.map(\.fingerprint) == [peerFingerprint])
+    }
+
+    @Test @MainActor
+    func vouchToConnectedVerifiedPeers_skipsUnverifiedConnectedPeers() {
+        let (context, coordinator) = makeVerifiedCapablePeer()
+        context.connectedPeerIDList = [peerID]
+        context.verifiedFingerprints.remove(peerFingerprint)
+        context.recentVerified = [String(repeating: "01", count: 32)]
+        context.signingKeysByFingerprint[context.recentVerified[0]] = Data(repeating: 0x33, count: 32)
+
+        coordinator.vouchToConnectedVerifiedPeers()
+        #expect(context.sentVouchPayloads.isEmpty)
+    }
+
+    @Test @MainActor
+    func peersUpdated_sendsOnceCapabilityBearingAnnounceArrives() {
+        let (context, coordinator) = makeVerifiedCapablePeer()
+        context.recentVerified = [String(repeating: "01", count: 32)]
+        context.signingKeysByFingerprint[context.recentVerified[0]] = Data(repeating: 0x33, count: 32)
+
+        // First announce before the .vouch bit is known: empty set is
+        // race-tolerant, so it already sends and stamps the throttle.
+        context.capabilitiesByPeerID[peerID] = []
+        coordinator.peersUpdated([peerID])
+        #expect(context.sentVouchPayloads.count == 1)
+
+        // A later announce carrying .vouch must not double-send (throttled).
+        context.capabilitiesByPeerID[peerID] = [.vouch]
+        coordinator.peersUpdated([peerID])
+        #expect(context.sentVouchPayloads.count == 1)
+    }
+
+    @Test @MainActor
+    func peerAuthenticated_rateLimitsPerPeerPer24Hours() {
+        let (context, coordinator) = makeVerifiedCapablePeer()
+        context.recentVerified = [String(repeating: "01", count: 32)]
+        context.signingKeysByFingerprint[context.recentVerified[0]] = Data(repeating: 0x33, count: 32)
+
+        let now = Date()
+        context.lastBatchSentAt[peerFingerprint] = now.addingTimeInterval(-60 * 60)
+        coordinator.peerAuthenticated(peerID, fingerprint: peerFingerprint, now: now)
+        #expect(context.sentVouchPayloads.isEmpty)
+
+        // Once the interval has elapsed the batch goes out again.
+        context.lastBatchSentAt[peerFingerprint] = now.addingTimeInterval(-ChatVouchCoordinator.batchInterval - 1)
+        coordinator.peerAuthenticated(peerID, fingerprint: peerFingerprint, now: now)
+        #expect(context.sentVouchPayloads.count == 1)
+    }
+
+    @Test @MainActor
+    func peerAuthenticated_skipsCandidatesWithoutSigningKeysAndEmptyBatches() {
+        let (context, coordinator) = makeVerifiedCapablePeer()
+        let withKey = String(repeating: "01", count: 32)
+        let withoutKey = String(repeating: "02", count: 32)
+        context.recentVerified = [withoutKey, withKey]
+        context.signingKeysByFingerprint[withKey] = Data(repeating: 0x33, count: 32)
+
+        coordinator.peerAuthenticated(peerID, fingerprint: peerFingerprint)
+        let attestations = VouchAttestation.decodeList(from: context.sentVouchPayloads[0].payload)
+        #expect(attestations.map(\.voucheeFingerprintHex) == [withKey])
+
+        // No signable candidates at all: nothing is sent or rate-stamped.
+        let freshPeer = PeerID(str: "aabbccddeeff0011")
+        let freshFingerprint = String(repeating: "0e", count: 32)
+        context.fingerprintsByPeerID[freshPeer] = freshFingerprint
+        context.verifiedFingerprints.insert(freshFingerprint)
+        context.capabilitiesByPeerID[freshPeer] = [.vouch]
+        context.recentVerified = [withoutKey]
+        coordinator.peerAuthenticated(freshPeer, fingerprint: freshFingerprint)
+        #expect(context.sentVouchPayloads.count == 1)
+        #expect(!context.markedBatchSent.contains { $0.fingerprint == freshFingerprint })
+    }
+
+    // MARK: Accept policy
+
+    @MainActor
+    private func makeInboundBatch(
+        signedBy key: Curve25519.Signing.PrivateKey,
+        vouchee: String = String(repeating: "07", count: 32),
+        timestampMs: UInt64 = UInt64(Date().timeIntervalSince1970 * 1000)
+    ) throws -> Data {
+        let voucheeData = try #require(Data(hexString: vouchee))
+        let attestation = try #require(VouchAttestation.build(
+            voucheeFingerprint: voucheeData,
+            voucheeSigningKey: Data(repeating: 0x44, count: 32),
+            timestampMs: timestampMs,
+            sign: { try? key.signature(for: $0) }
+        ))
+        return try #require(VouchAttestation.encodeList([attestation]))
+    }
+
+    @Test @MainActor
+    func handleVouchPayload_acceptsValidVouchFromVerifiedSender() throws {
+        let (context, coordinator) = makeVerifiedCapablePeer()
+        let senderKey = Curve25519.Signing.PrivateKey()
+        context.signingKeysByFingerprint[peerFingerprint] = senderKey.publicKey.rawRepresentation
+
+        let vouchee = String(repeating: "07", count: 32)
+        let payload = try makeInboundBatch(signedBy: senderKey, vouchee: vouchee)
+        coordinator.handleVouchPayload(from: peerID, payload: payload)
+
+        #expect(context.recordedVouches.count == 1)
+        #expect(context.recordedVouches.first?.vouchee == vouchee)
+        #expect(context.recordedVouches.first?.voucher == peerFingerprint)
+        #expect(context.trustChangedCount == 1)
+    }
+
+    @Test @MainActor
+    func handleVouchPayload_rejectsUnverifiedOrUnknownSender() throws {
+        let (context, coordinator) = makeVerifiedCapablePeer()
+        let senderKey = Curve25519.Signing.PrivateKey()
+        context.signingKeysByFingerprint[peerFingerprint] = senderKey.publicKey.rawRepresentation
+        let payload = try makeInboundBatch(signedBy: senderKey)
+
+        // Sender's fingerprint is not in my verified set.
+        context.verifiedFingerprints.remove(peerFingerprint)
+        coordinator.handleVouchPayload(from: peerID, payload: payload)
+        #expect(context.recordedVouches.isEmpty)
+
+        // Unknown peer entirely.
+        coordinator.handleVouchPayload(from: PeerID(str: "ffeeddccbbaa9988"), payload: payload)
+        #expect(context.recordedVouches.isEmpty)
+        #expect(context.trustChangedCount == 0)
+    }
+
+    @Test @MainActor
+    func handleVouchPayload_rejectsForgedSignaturesAndExpiredAttestations() throws {
+        let (context, coordinator) = makeVerifiedCapablePeer()
+        let senderKey = Curve25519.Signing.PrivateKey()
+        context.signingKeysByFingerprint[peerFingerprint] = senderKey.publicKey.rawRepresentation
+
+        // Signed by an imposter key: signature check against the sender's
+        // announce-bound key fails.
+        let imposter = Curve25519.Signing.PrivateKey()
+        let forged = try makeInboundBatch(signedBy: imposter)
+        coordinator.handleVouchPayload(from: peerID, payload: forged)
+        #expect(context.recordedVouches.isEmpty)
+
+        // Correctly signed but expired.
+        let staleMs = UInt64(Date().addingTimeInterval(-31 * 24 * 60 * 60).timeIntervalSince1970 * 1000)
+        let expired = try makeInboundBatch(signedBy: senderKey, timestampMs: staleMs)
+        coordinator.handleVouchPayload(from: peerID, payload: expired)
+        #expect(context.recordedVouches.isEmpty)
+        #expect(context.trustChangedCount == 0)
+
+        // No signing key known for the sender: batch dropped.
+        context.signingKeysByFingerprint.removeValue(forKey: peerFingerprint)
+        let valid = try makeInboundBatch(signedBy: senderKey)
+        coordinator.handleVouchPayload(from: peerID, payload: valid)
+        #expect(context.recordedVouches.isEmpty)
+    }
+
+    @Test @MainActor
+    func handleVouchPayload_skipsUIRefreshWhenNothingStored() throws {
+        let (context, coordinator) = makeVerifiedCapablePeer()
+        let senderKey = Curve25519.Signing.PrivateKey()
+        context.signingKeysByFingerprint[peerFingerprint] = senderKey.publicKey.rawRepresentation
+        context.recordVouchResult = false // e.g. self-vouch dropped by the store
+
+        let payload = try makeInboundBatch(signedBy: senderKey)
+        coordinator.handleVouchPayload(from: peerID, payload: payload)
+        #expect(context.recordedVouches.count == 1)
+        #expect(context.trustChangedCount == 0)
+    }
+
+    @Test @MainActor
+    func setupNoiseCallbacks_installsAdditiveObserver() {
+        let (context, coordinator) = makeVerifiedCapablePeer()
+        coordinator.setupNoiseCallbacks()
+        #expect(context.installedObservers.count == 1)
+    }
+}

bitchatTests/CommandProcessorTests.swift

@@ -370,6 +370,173 @@ struct CommandProcessorTests {
         }
     }
 
+    // MARK: - /pay
+
+    @MainActor
+    @Test func payWithoutArgumentsPrintsUsage() {
+        let processor = makePayProcessor(context: MockCommandContextProvider())
+        switch processor.process("/pay") {
+        case .success(let message):
+            #expect(message?.contains("usage: /pay") == true)
+        default:
+            Issue.record("Expected success (usage) result")
+        }
+    }
+
+    @MainActor
+    @Test func payRejectsInvalidToken() {
+        let context = MockCommandContextProvider()
+        let processor = makePayProcessor(context: context)
+        for bad in ["/pay nonsense", "/pay cashuAshort", "/pay cashuA!!!!!!!!!!!!!!!!"] {
+            switch processor.process(bad) {
+            case .error:
+                break
+            default:
+                Issue.record("Expected error for \(bad)")
+            }
+        }
+        #expect(context.sentPrivateMessages.isEmpty)
+        #expect(context.sentPublicMessages.isEmpty)
+    }
+
+    @MainActor
+    @Test func paySendsBareTokenInPrivateChat() {
+        let context = MockCommandContextProvider()
+        let peerID = PeerID(str: "abcd1234abcd1234")
+        context.selectedPrivateChatPeer = peerID
+        let processor = makePayProcessor(context: context)
+
+        // cashu: URI form must be normalized to the bare token before sending
+        switch processor.process("/pay cashu:\(Self.validV3Token)") {
+        case .success(let message):
+            #expect(message?.contains("21 sat") == true)
+        default:
+            Issue.record("Expected success result")
+        }
+        #expect(context.sentPrivateMessages.count == 1)
+        #expect(context.sentPrivateMessages.first?.content == Self.validV3Token)
+        #expect(context.sentPrivateMessages.first?.peerID == peerID)
+        #expect(context.sentPublicMessages.isEmpty)
+    }
+
+    @MainActor
+    @Test func payInPublicChannelRequiresExplicitConfirm() {
+        let context = MockCommandContextProvider()
+        let processor = makePayProcessor(context: context)
+
+        switch processor.process("/pay \(Self.validV3Token)") {
+        case .error(let message):
+            #expect(message.contains("public") == true)
+        default:
+            Issue.record("Expected error without confirm")
+        }
+        #expect(context.sentPublicMessages.isEmpty)
+
+        switch processor.process("/pay \(Self.validV3Token) public") {
+        case .success:
+            break
+        default:
+            Issue.record("Expected success with confirm")
+        }
+        #expect(context.sentPublicMessages == [Self.validV3Token])
+        #expect(context.sentPrivateMessages.isEmpty)
+    }
+
+    @MainActor
+    @Test func payRejectsTruncatedOrJunkV4Token() {
+        let context = MockCommandContextProvider()
+        context.selectedPrivateChatPeer = PeerID(str: "abcd1234abcd1234")
+        let processor = makePayProcessor(context: context)
+
+        // Truncated V4 (definite-length CBOR can no longer be walked) and
+        // pure base64 junk under the cashuB prefix must both be refused.
+        let truncatedV4 = String(Self.validV4Token.prefix(Self.validV4Token.count - 12))
+        let junkV4 = "cashuB" + String(repeating: "Q", count: 40)
+        for bad in ["/pay \(truncatedV4)", "/pay \(junkV4)"] {
+            switch processor.process(bad) {
+            case .error(let message):
+                #expect(message.contains("invalid cashu token") == true)
+            default:
+                Issue.record("Expected error for \(bad)")
+            }
+        }
+        #expect(context.sentPrivateMessages.isEmpty)
+        #expect(context.sentPublicMessages.isEmpty)
+    }
+
+    @MainActor
+    @Test func paySendsValidDefiniteLengthV4Token() {
+        let context = MockCommandContextProvider()
+        let peerID = PeerID(str: "abcd1234abcd1234")
+        context.selectedPrivateChatPeer = peerID
+        let processor = makePayProcessor(context: context)
+
+        switch processor.process("/pay \(Self.validV4Token)") {
+        case .success(let message):
+            #expect(message?.contains("21 sat") == true)
+        default:
+            Issue.record("Expected success result for valid V4 token")
+        }
+        #expect(context.sentPrivateMessages.count == 1)
+        #expect(context.sentPrivateMessages.first?.content == Self.validV4Token)
+    }
+
+    /// 21-sat single-mint V3 token (proofs of 1+4+16).
+    private static let validV3Token: String = {
+        let json: [String: Any] = [
+            "token": [[
+                "mint": "https://mint.example.com",
+                "proofs": [1, 4, 16].map { ["amount": $0, "id": "009a1f293253e41e", "secret": "s", "C": "02c"] }
+            ]],
+            "unit": "sat"
+        ]
+        let data = try! JSONSerialization.data(withJSONObject: json)
+        let b64 = data.base64EncodedString()
+            .replacingOccurrences(of: "+", with: "-")
+            .replacingOccurrences(of: "/", with: "_")
+            .replacingOccurrences(of: "=", with: "")
+        return "cashuA" + b64
+    }()
+
+    /// 21-sat single-mint definite-length V4 (CBOR) token (proofs of 1+4+16).
+    private static let validV4Token: String = {
+        func head(_ major: UInt8, _ value: UInt64) -> [UInt8] {
+            switch value {
+            case 0...23: return [(major << 5) | UInt8(value)]
+            case 24...0xFF: return [(major << 5) | 24, UInt8(value)]
+            default: return [(major << 5) | 25, UInt8(value >> 8), UInt8(value & 0xFF)]
+            }
+        }
+        func text(_ s: String) -> [UInt8] { head(3, UInt64(s.utf8.count)) + Array(s.utf8) }
+        func bytes(_ b: [UInt8]) -> [UInt8] { head(2, UInt64(b.count)) + b }
+        func uint(_ v: UInt64) -> [UInt8] { head(0, v) }
+        func array(_ items: [[UInt8]]) -> [UInt8] { head(4, UInt64(items.count)) + items.flatMap { $0 } }
+        func map(_ pairs: [(String, [UInt8])]) -> [UInt8] { head(5, UInt64(pairs.count)) + pairs.flatMap { text($0.0) + $0.1 } }
+
+        let proofs = [UInt64(1), 4, 16].map { amount in
+            map([("a", uint(amount)), ("s", text("secret")), ("c", bytes([0x02, 0xAB, 0xCD]))])
+        }
+        let cbor = map([
+            ("m", text("https://mint.example.com")),
+            ("u", text("sat")),
+            ("t", array([map([("i", bytes([0x00, 0xAD, 0x26, 0x8C])), ("p", array(proofs))])]))
+        ])
+        let b64 = Data(cbor).base64EncodedString()
+            .replacingOccurrences(of: "+", with: "-")
+            .replacingOccurrences(of: "/", with: "_")
+            .replacingOccurrences(of: "=", with: "")
+        return "cashuB" + b64
+    }()
+
+    @MainActor
+    private func makePayProcessor(context: MockCommandContextProvider) -> CommandProcessor {
+        CommandProcessor(
+            contextProvider: context,
+            meshService: MockTransport(),
+            identityManager: MockIdentityManager(MockKeychain())
+        )
+    }
+
     @MainActor
     private func withSelectedChannel<T>(
         _ channel: ChannelID,
@@ -435,6 +602,8 @@ private final class MockCommandContextProvider: CommandContextProvider {
     private(set) var sentPublicRawMessages: [String] = []
     private(set) var localPrivateSystemMessages: [(content: String, peerID: PeerID)] = []
     private(set) var publicSystemMessages: [String] = []
+    private(set) var commandOutputs: [String] = []
+    private(set) var commandOutputDestinations: [CommandOutputDestination] = []
     private(set) var toggledFavorites: [PeerID] = []
     private(set) var favoriteNotifications: [(peerID: PeerID, isFavorite: Bool)] = []
 
@@ -477,6 +646,11 @@ private final class MockCommandContextProvider: CommandContextProvider {
         sentPublicRawMessages.append(content)
     }
 
+    private(set) var sentPublicMessages: [String] = []
+    func sendPublicMessage(_ content: String) {
+        sentPublicMessages.append(content)
+    }
+
     func addLocalPrivateSystemMessage(_ content: String, to peerID: PeerID) {
         localPrivateSystemMessages.append((content, peerID))
     }
@@ -485,6 +659,18 @@ private final class MockCommandContextProvider: CommandContextProvider {
         publicSystemMessages.append(content)
     }
 
+    func currentCommandDestination() -> CommandOutputDestination {
+        if let peerID = selectedPrivateChatPeer {
+            return .privateChat(peerID)
+        }
+        return .meshTimeline
+    }
+
+    func addCommandOutput(_ content: String, to destination: CommandOutputDestination) {
+        commandOutputs.append(content)
+        commandOutputDestinations.append(destination)
+    }
+
     func toggleFavorite(peerID: PeerID) {
         toggledFavorites.append(peerID)
     }
@@ -492,4 +678,32 @@ private final class MockCommandContextProvider: CommandContextProvider {
     func sendFavoriteNotification(to peerID: PeerID, isFavorite: Bool) {
         favoriteNotifications.append((peerID, isFavorite))
     }
+
+    // Groups: record the parsed subcommand + argument the processor forwarded.
+    private(set) var groupCommands: [(subcommand: String, argument: String)] = []
+
+    func groupCreate(named name: String) -> CommandResult {
+        groupCommands.append(("create", name))
+        return .handled
+    }
+
+    func groupInvite(nickname: String) -> CommandResult {
+        groupCommands.append(("invite", nickname))
+        return .handled
+    }
+
+    func groupRemove(nickname: String) -> CommandResult {
+        groupCommands.append(("remove", nickname))
+        return .handled
+    }
+
+    func groupLeave() -> CommandResult {
+        groupCommands.append(("leave", ""))
+        return .handled
+    }
+
+    func groupList() -> CommandResult {
+        groupCommands.append(("list", ""))
+        return .handled
+    }
 }

bitchatTests/EndToEnd/PrekeyEndToEndTests.swift

@@ -0,0 +1,399 @@
+//
+// PrekeyEndToEndTests.swift
+// bitchat
+//
+// This is free and unencumbered software released into the public domain.
+// For more information, see <https://unlicense.org>
+//
+
+import Testing
+import Foundation
+import CoreBluetooth
+import BitFoundation
+@testable import bitchat
+
+/// Forward-secret courier flow through real BLEService instances: Bob gossips
+/// a signed prekey bundle, Alice verifies and caches it, seals to a one-time
+/// prekey instead of Bob's static key, Carol carries the opaque envelope, and
+/// Bob opens it with the matching prekey private.
+struct PrekeyEndToEndTests {
+
+    // MARK: - Helpers
+
+    private final class PacketTap {
+        private let lock = NSLock()
+        private var packets: [BitchatPacket] = []
+
+        func record(_ packet: BitchatPacket) {
+            lock.lock(); packets.append(packet); lock.unlock()
+        }
+
+        func first(ofType type: MessageType) -> BitchatPacket? {
+            lock.lock(); defer { lock.unlock() }
+            return packets.first { $0.type == type.rawValue }
+        }
+    }
+
+    private final class NoiseCaptureDelegate: BitchatDelegate {
+        private let lock = NSLock()
+        private var payloads: [(peerID: PeerID, type: NoisePayloadType, payload: Data)] = []
+
+        func didReceiveNoisePayload(from peerID: PeerID, type: NoisePayloadType, payload: Data, timestamp: Date) {
+            lock.lock(); payloads.append((peerID, type, payload)); lock.unlock()
+        }
+
+        func snapshot() -> [(peerID: PeerID, type: NoisePayloadType, payload: Data)] {
+            lock.lock(); defer { lock.unlock() }
+            return payloads
+        }
+
+        // Unused BitchatDelegate requirements.
+        func didReceiveMessage(_ message: BitchatMessage) {}
+        func didConnectToPeer(_ peerID: PeerID) {}
+        func didDisconnectFromPeer(_ peerID: PeerID) {}
+        func didUpdatePeerList(_ peers: [PeerID]) {}
+        func didUpdateBluetoothState(_ state: CBManagerState) {}
+        func didReceivePublicMessage(from peerID: PeerID, nickname: String, content: String, timestamp: Date, messageID: String?) {}
+    }
+
+    private func makeService() -> BLEService {
+        let keychain = MockKeychain()
+        let service = BLEService(
+            keychain: keychain,
+            idBridge: NostrIdentityBridge(keychain: MockKeychainHelper()),
+            identityManager: MockIdentityManager(keychain),
+            initializeBluetoothManagers: false
+        )
+        service.courierStore = CourierStore(persistsToDisk: false)
+        service.prekeyBundleStore = PrekeyBundleStore(persistsToDisk: false)
+        return service
+    }
+
+    private func preseedConnectedPeer(_ peer: BLEService, in service: BLEService) {
+        let packet = BitchatPacket(
+            type: MessageType.message.rawValue,
+            senderID: Data(hexString: peer.myPeerID.id) ?? Data(),
+            recipientID: nil,
+            timestamp: UInt64(Date().timeIntervalSince1970 * 1000),
+            payload: Data("ping".utf8),
+            signature: nil,
+            ttl: 1
+        )
+        service._test_handlePacket(packet, fromPeerID: peer.myPeerID)
+    }
+
+    /// Broadcast announce + prekey bundle from `peer` and return both packets.
+    private func captureAnnounceAndBundle(from peer: BLEService, tap: PacketTap) async throws -> (announce: BitchatPacket, bundle: BitchatPacket) {
+        peer.sendBroadcastAnnounce()
+        let published = await TestHelpers.waitUntil(
+            { tap.first(ofType: .announce) != nil && tap.first(ofType: .prekeyBundle) != nil },
+            timeout: TestConstants.defaultTimeout
+        )
+        #expect(published)
+        return (
+            announce: try #require(tap.first(ofType: .announce)),
+            bundle: try #require(tap.first(ofType: .prekeyBundle))
+        )
+    }
+
+    // MARK: - Tests
+
+    @Test func prekeySealedMailTravelsViaCourierAndOpens() async throws {
+        let alice = makeService()
+        let carol = makeService()
+        let bob = makeService()
+        carol.courierDepositPolicy = { _, _ in .favorite }
+
+        let bobDelegate = NoiseCaptureDelegate()
+        bob.delegate = bobDelegate
+
+        let aliceOut = PacketTap()
+        alice._test_onOutboundPacket = aliceOut.record
+        let carolOut = PacketTap()
+        carol._test_onOutboundPacket = carolOut.record
+        let bobOut = PacketTap()
+        bob._test_onOutboundPacket = bobOut.record
+
+        preseedConnectedPeer(carol, in: alice)
+
+        // 1. While Bob is still around, Alice hears his verified announce
+        //    (binding his signing key) and his gossiped prekey bundle.
+        let (announce, bundlePacket) = try await captureAnnounceAndBundle(from: bob, tap: bobOut)
+        alice._test_handlePacket(announce, fromPeerID: bob.myPeerID, preseedPeer: false)
+        alice._test_handlePacket(bundlePacket, fromPeerID: bob.myPeerID, preseedPeer: false)
+
+        let cached = await TestHelpers.waitUntil(
+            { alice.prekeyBundleStore.hasUsableBundle(for: bob.noiseStaticPublicKeyData()) },
+            timeout: TestConstants.defaultTimeout
+        )
+        #expect(cached)
+
+        // 2. Bob goes dark; Alice seals for him and deposits with Carol.
+        //    The envelope must be v2: sealed to a one-time prekey.
+        #expect(alice.sendCourierMessage(
+            "burn after reading",
+            messageID: "prekey-msg-1",
+            recipientNoiseKey: bob.noiseStaticPublicKeyData(),
+            via: [carol.myPeerID]
+        ))
+        let deposited = await TestHelpers.waitUntil(
+            { aliceOut.first(ofType: .courierEnvelope) != nil },
+            timeout: TestConstants.defaultTimeout
+        )
+        #expect(deposited)
+        let depositPacket = try #require(aliceOut.first(ofType: .courierEnvelope))
+        let sealedEnvelope = try #require(CourierEnvelope.decode(depositPacket.payload))
+        #expect(sealedEnvelope.prekeyID != nil)
+
+        // 3. Carol carries it (opaque, prekey or not).
+        carol._test_handlePacket(depositPacket, fromPeerID: alice.myPeerID, signingPublicKey: alice.noiseSigningPublicKeyData())
+        let carried = await TestHelpers.waitUntil(
+            { !carol.courierStore.isEmpty },
+            timeout: TestConstants.defaultTimeout
+        )
+        #expect(carried)
+
+        // 4. Bob resurfaces near Carol → handover, and the v2 discriminator
+        //    survives the store round-trip.
+        bob.sendBroadcastAnnounce()
+        let reannounced = await TestHelpers.waitUntil(
+            { bobOut.first(ofType: .announce) != nil },
+            timeout: TestConstants.defaultTimeout
+        )
+        #expect(reannounced)
+        let handoverTrigger = try #require(bobOut.first(ofType: .announce))
+        carol._test_handlePacket(handoverTrigger, fromPeerID: bob.myPeerID, preseedPeer: false)
+
+        let handedOver = await TestHelpers.waitUntil(
+            { carolOut.first(ofType: .courierEnvelope) != nil },
+            timeout: TestConstants.defaultTimeout
+        )
+        #expect(handedOver)
+        let handoverPacket = try #require(carolOut.first(ofType: .courierEnvelope))
+        let handedEnvelope = try #require(CourierEnvelope.decode(handoverPacket.payload))
+        #expect(handedEnvelope.prekeyID == sealedEnvelope.prekeyID)
+
+        // 5. Bob opens it with the matching one-time prekey private and sees
+        //    Alice as the authenticated sender.
+        bob._test_handlePacket(handoverPacket, fromPeerID: carol.myPeerID)
+        let received = await TestHelpers.waitUntil(
+            { !bobDelegate.snapshot().isEmpty },
+            timeout: TestConstants.defaultTimeout
+        )
+        #expect(received)
+
+        let delivered = try #require(bobDelegate.snapshot().first)
+        #expect(delivered.type == .privateMessage)
+        #expect(delivered.peerID == PeerID(hexData: alice.noiseStaticPublicKeyData()))
+        let message = try #require(PrivateMessagePacket.decode(from: delivered.payload))
+        #expect(message.messageID == "prekey-msg-1")
+        #expect(message.content == "burn after reading")
+
+        // 6. Redelivery tolerance: the same envelope arriving via another
+        //    packet (spray-and-wait) still opens inside the grace window.
+        let redelivery = BitchatPacket(
+            type: MessageType.courierEnvelope.rawValue,
+            senderID: Data(hexString: carol.myPeerID.id) ?? Data(),
+            recipientID: handoverPacket.recipientID,
+            timestamp: handoverPacket.timestamp + 1,
+            payload: handoverPacket.payload,
+            signature: nil,
+            ttl: 1
+        )
+        bob._test_handlePacket(redelivery, fromPeerID: carol.myPeerID)
+        let redelivered = await TestHelpers.waitUntil(
+            { bobDelegate.snapshot().count == 2 },
+            timeout: TestConstants.defaultTimeout
+        )
+        #expect(redelivered)
+    }
+
+    @Test func withoutBundleSealingFallsBackToStatic() async throws {
+        let alice = makeService()
+        let bob = makeService()
+
+        let bobDelegate = NoiseCaptureDelegate()
+        bob.delegate = bobDelegate
+        let aliceOut = PacketTap()
+        alice._test_onOutboundPacket = aliceOut.record
+
+        // Bob is a connected "courier" who happens to be the recipient: the
+        // envelope reaches him directly and the recipient tag matches.
+        preseedConnectedPeer(bob, in: alice)
+
+        // Alice never saw a bundle for Bob → v1 static-sealed envelope.
+        #expect(alice.sendCourierMessage(
+            "plain static seal",
+            messageID: "static-msg-1",
+            recipientNoiseKey: bob.noiseStaticPublicKeyData(),
+            via: [bob.myPeerID]
+        ))
+        let deposited = await TestHelpers.waitUntil(
+            { aliceOut.first(ofType: .courierEnvelope) != nil },
+            timeout: TestConstants.defaultTimeout
+        )
+        #expect(deposited)
+        let depositPacket = try #require(aliceOut.first(ofType: .courierEnvelope))
+        let envelope = try #require(CourierEnvelope.decode(depositPacket.payload))
+        #expect(envelope.prekeyID == nil)
+
+        // Bob opens the v1 envelope exactly as before the prekey change.
+        // (No preseed: Alice is absent from Bob's mesh, so the sender should
+        // resolve to her full noise-key ID like the courier case.)
+        bob._test_handlePacket(depositPacket, fromPeerID: alice.myPeerID, preseedPeer: false)
+        let received = await TestHelpers.waitUntil(
+            { !bobDelegate.snapshot().isEmpty },
+            timeout: TestConstants.defaultTimeout
+        )
+        #expect(received)
+        let delivered = try #require(bobDelegate.snapshot().first)
+        #expect(delivered.peerID == PeerID(hexData: alice.noiseStaticPublicKeyData()))
+        let message = try #require(PrivateMessagePacket.decode(from: delivered.payload))
+        #expect(message.content == "plain static seal")
+    }
+
+    @Test func unverifiableBundleIsIgnored() async throws {
+        let alice = makeService()
+        let bob = makeService()
+
+        let bobOut = PacketTap()
+        bob._test_onOutboundPacket = bobOut.record
+
+        // Alice receives Bob's bundle but never saw a verified announce, so
+        // no signing key is bound to his noise key: the bundle must not be
+        // cached or enter Alice's gossip store.
+        let (_, bundlePacket) = try await captureAnnounceAndBundle(from: bob, tap: bobOut)
+        alice._test_handlePacket(bundlePacket, fromPeerID: bob.myPeerID, preseedPeer: false)
+
+        let cached = await TestHelpers.waitUntil(
+            { alice.prekeyBundleStore.hasUsableBundle(for: bob.noiseStaticPublicKeyData()) },
+            timeout: TestConstants.shortTimeout
+        )
+        #expect(!cached)
+    }
+
+    @Test func forgedBundleSignatureIsRejected() async throws {
+        let alice = makeService()
+        let bob = makeService()
+
+        let bobOut = PacketTap()
+        bob._test_onOutboundPacket = bobOut.record
+
+        let (announce, bundlePacket) = try await captureAnnounceAndBundle(from: bob, tap: bobOut)
+        alice._test_handlePacket(announce, fromPeerID: bob.myPeerID, preseedPeer: false)
+
+        // Mallory tampers with the gossiped bundle in flight.
+        let bundle = try #require(PrekeyBundle.decode(bundlePacket.payload))
+        var forgedSignature = bundle.signature
+        forgedSignature[0] ^= 0x01
+        let forged = PrekeyBundle(
+            noiseStaticPublicKey: bundle.noiseStaticPublicKey,
+            prekeys: bundle.prekeys,
+            generatedAt: bundle.generatedAt,
+            signature: forgedSignature
+        )
+        let forgedPacket = BitchatPacket(
+            type: MessageType.prekeyBundle.rawValue,
+            senderID: bundlePacket.senderID,
+            recipientID: nil,
+            timestamp: bundlePacket.timestamp,
+            payload: try #require(forged.encode()),
+            signature: bundlePacket.signature,
+            ttl: bundlePacket.ttl
+        )
+        alice._test_handlePacket(forgedPacket, fromPeerID: bob.myPeerID, preseedPeer: false)
+
+        let cached = await TestHelpers.waitUntil(
+            { alice.prekeyBundleStore.hasUsableBundle(for: bob.noiseStaticPublicKeyData()) },
+            timeout: TestConstants.shortTimeout
+        )
+        #expect(!cached)
+    }
+
+    @Test func verifiedBundleEntersGossipStore() async throws {
+        let alice = makeService()
+        let bob = makeService()
+
+        let bobOut = PacketTap()
+        bob._test_onOutboundPacket = bobOut.record
+
+        let (announce, bundlePacket) = try await captureAnnounceAndBundle(from: bob, tap: bobOut)
+        alice._test_handlePacket(announce, fromPeerID: bob.myPeerID, preseedPeer: false)
+        alice._test_handlePacket(bundlePacket, fromPeerID: bob.myPeerID, preseedPeer: false)
+
+        let cached = await TestHelpers.waitUntil(
+            { alice.prekeyBundleStore.hasUsableBundle(for: bob.noiseStaticPublicKeyData()) },
+            timeout: TestConstants.defaultTimeout
+        )
+        #expect(cached)
+        // The verified bundle now participates in Alice's sync rounds.
+        #expect(alice._test_hasGossipPrekeyBundle(for: bob.myPeerID))
+    }
+
+    @Test func spoofedSenderPrekeyBundleIsRejected() async throws {
+        let alice = makeService()
+        let bob = makeService()
+
+        let bobOut = PacketTap()
+        bob._test_onOutboundPacket = bobOut.record
+
+        let (announce, bundlePacket) = try await captureAnnounceAndBundle(from: bob, tap: bobOut)
+        alice._test_handlePacket(announce, fromPeerID: bob.myPeerID, preseedPeer: false)
+
+        // A relay re-broadcasts Bob's genuine bundle under a fabricated sender
+        // ID (the DoS that would multiply cache/gossip entries and exhaust the
+        // per-owner cap). Attribution is by the bundle's own key and the outer
+        // signature is bound to Bob's sender ID, so the spoof is dropped — no
+        // cache entry, and no gossip entry under either the fake or real ID.
+        let fakeSender = Data((0..<8).map { _ in UInt8.random(in: 0...255) })
+        let spoofed = BitchatPacket(
+            type: MessageType.prekeyBundle.rawValue,
+            senderID: fakeSender,
+            recipientID: nil,
+            timestamp: bundlePacket.timestamp + 5_000,
+            payload: bundlePacket.payload,
+            signature: bundlePacket.signature,
+            ttl: bundlePacket.ttl
+        )
+        alice._test_handlePacket(spoofed, fromPeerID: PeerID(hexData: fakeSender), preseedPeer: false)
+
+        let cached = await TestHelpers.waitUntil(
+            { alice.prekeyBundleStore.hasUsableBundle(for: bob.noiseStaticPublicKeyData()) },
+            timeout: TestConstants.shortTimeout
+        )
+        #expect(!cached)
+        #expect(!alice._test_hasGossipPrekeyBundle(for: bob.myPeerID))
+        #expect(!alice._test_hasGossipPrekeyBundle(for: PeerID(hexData: fakeSender)))
+    }
+
+    @Test func replayedPrekeyBundleWithFreshTimestampIsRejected() async throws {
+        let alice = makeService()
+        let bob = makeService()
+
+        let bobOut = PacketTap()
+        bob._test_onOutboundPacket = bobOut.record
+
+        let (announce, bundlePacket) = try await captureAnnounceAndBundle(from: bob, tap: bobOut)
+        alice._test_handlePacket(announce, fromPeerID: bob.myPeerID, preseedPeer: false)
+
+        // Rewriting the outer timestamp (to defeat the freshness window)
+        // invalidates the packet signature, which covers senderID + timestamp.
+        let replay = BitchatPacket(
+            type: MessageType.prekeyBundle.rawValue,
+            senderID: bundlePacket.senderID,
+            recipientID: nil,
+            timestamp: bundlePacket.timestamp + 5_000,
+            payload: bundlePacket.payload,
+            signature: bundlePacket.signature,
+            ttl: bundlePacket.ttl
+        )
+        alice._test_handlePacket(replay, fromPeerID: bob.myPeerID, preseedPeer: false)
+
+        let cached = await TestHelpers.waitUntil(
+            { alice.prekeyBundleStore.hasUsableBundle(for: bob.noiseStaticPublicKeyData()) },
+            timeout: TestConstants.shortTimeout
+        )
+        #expect(!cached)
+        #expect(!alice._test_hasGossipPrekeyBundle(for: bob.myPeerID))
+    }
+}

bitchatTests/GossipSyncManagerTests.swift

@@ -139,6 +139,7 @@ struct GossipSyncManagerTests {
         config.messageSyncIntervalSeconds = 1
         config.fragmentSyncIntervalSeconds = 1
         config.fileTransferSyncIntervalSeconds = 1
+        config.prekeyBundleSyncIntervalSeconds = 1
         config.maintenanceIntervalSeconds = 0
 
         let requestSyncManager = RequestSyncManager()
@@ -195,19 +196,25 @@ struct GossipSyncManagerTests {
         manager._performMaintenanceSynchronously(now: Date())
 
         // One request per due schedule so each type group gets the full
-        // filter capacity: publicMessages, fragment, and fileTransfer.
+        // filter capacity: publicMessages, fragment, fileTransfer, and
+        // prekeyBundle.
         let sentPackets = delegate.packets
-        #expect(sentPackets.count == 3)
+        #expect(sentPackets.count == 4)
         let decoded = sentPackets.compactMap { RequestSyncPacket.decode(from: $0.payload) }
-        #expect(decoded.count == 3)
+        #expect(decoded.count == 4)
         let allTypes = decoded.compactMap(\.types).reduce(SyncTypeFlags(rawValue: 0)) { $0.union($1) }
         #expect(allTypes.contains(.announce))
         #expect(allTypes.contains(.message))
         #expect(allTypes.contains(.fragment))
         #expect(allTypes.contains(.fileTransfer))
-        #expect(decoded.contains { $0.types == .publicMessages })
+        #expect(allTypes.contains(.prekeyBundle))
+        #expect(allTypes.contains(.groupMessage))
+        // The message schedule also asks for group messages (bit 10);
+        // responders that don't know the bit just ignore it.
+        #expect(decoded.contains { $0.types == SyncTypeFlags.publicMessages.union(.groupMessage) })
         #expect(decoded.contains { $0.types == .fragment })
         #expect(decoded.contains { $0.types == .fileTransfer })
+        #expect(decoded.contains { $0.types == .prekeyBundle })
     }
 
     @Test func truncatedFilterCarriesSinceCursor() throws {
@@ -292,6 +299,7 @@ struct GossipSyncManagerTests {
         config.messageSyncIntervalSeconds = 0
         config.fragmentSyncIntervalSeconds = 0
         config.fileTransferSyncIntervalSeconds = 0
+        config.prekeyBundleSyncIntervalSeconds = 0
 
         let requestSyncManager = RequestSyncManager()
         let manager = GossipSyncManager(myPeerID: myPeerID, config: config, requestSyncManager: requestSyncManager)
@@ -362,6 +370,7 @@ struct GossipSyncManagerTests {
         config.messageSyncIntervalSeconds = 0
         config.fragmentSyncIntervalSeconds = 0
         config.fileTransferSyncIntervalSeconds = 0
+        config.prekeyBundleSyncIntervalSeconds = 0
 
         let requestSyncManager = RequestSyncManager()
         let manager = GossipSyncManager(myPeerID: myPeerID, config: config, requestSyncManager: requestSyncManager)
@@ -401,6 +410,7 @@ struct GossipSyncManagerTests {
         config.messageSyncIntervalSeconds = 0
         config.fragmentSyncIntervalSeconds = 0
         config.fileTransferSyncIntervalSeconds = 0
+        config.prekeyBundleSyncIntervalSeconds = 0
         config.responseRateLimitMaxResponses = 1
         config.responseRateLimitWindowSeconds = 60
 
@@ -455,6 +465,7 @@ struct GossipSyncManagerTests {
         #expect(types.contains(.message))
         #expect(types.contains(.fragment))
         #expect(types.contains(.fileTransfer))
+        #expect(types.contains(.prekeyBundle))
     }
 
     @Test func handleRequestSyncHonorsTypeFilter() async throws {
@@ -507,6 +518,185 @@ struct GossipSyncManagerTests {
         #expect(sentPackets[0].type == MessageType.fragment.rawValue)
     }
 
+    // MARK: - Fragment-ID filter (targeted resync)
+
+    private func makeFragmentPacket(sender: Data, fragmentID: Data, index: UInt16, timestamp: UInt64) -> BitchatPacket {
+        // Fragment payload: 8-byte stream ID + index + total + original type.
+        var payload = fragmentID
+        payload.append(contentsOf: withUnsafeBytes(of: index.bigEndian) { Data($0) })
+        payload.append(contentsOf: withUnsafeBytes(of: UInt16(4).bigEndian) { Data($0) })
+        payload.append(MessageType.fileTransfer.rawValue)
+        payload.append(Data([0xEE]))
+        return BitchatPacket(
+            type: MessageType.fragment.rawValue,
+            senderID: sender,
+            recipientID: nil,
+            timestamp: timestamp,
+            payload: payload,
+            signature: nil,
+            ttl: 1
+        )
+    }
+
+    @Test func handleRequestSyncHonorsFragmentIdFilter() async throws {
+        var config = GossipSyncManager.Config()
+        config.fragmentCapacity = 10
+        config.messageSyncIntervalSeconds = 0
+        config.fragmentSyncIntervalSeconds = 0
+        config.fileTransferSyncIntervalSeconds = 0
+        config.prekeyBundleSyncIntervalSeconds = 0
+
+        let requestSyncManager = RequestSyncManager()
+        let manager = GossipSyncManager(myPeerID: myPeerID, config: config, requestSyncManager: requestSyncManager)
+        let delegate = RecordingDelegate()
+        manager.delegate = delegate
+
+        let sender = try #require(Data(hexString: "aabbccddeeff0011"))
+        let wantedID = try #require(Data(hexString: "0102030405060708"))
+        let otherID = try #require(Data(hexString: "1112131415161718"))
+        let nowMs = UInt64(Date().timeIntervalSince1970 * 1000)
+
+        let wanted = makeFragmentPacket(sender: sender, fragmentID: wantedID, index: 1, timestamp: nowMs - 60_000)
+        let other = makeFragmentPacket(sender: sender, fragmentID: otherID, index: 2, timestamp: nowMs)
+        manager.onPublicPacketSeen(wanted)
+        manager.onPublicPacketSeen(other)
+
+        // The since-cursor sits after both fragments; without the filter the
+        // responder would send nothing for `wanted`. The filter both bypasses
+        // the cursor and restricts the diff to exactly the named stream.
+        let request = RequestSyncPacket(
+            p: 7,
+            m: 1,
+            data: Data(),
+            types: .fragment,
+            sinceTimestamp: nowMs + 1,
+            fragmentIdFilter: RequestSyncPacket.encodeFragmentIdFilter([wantedID])
+        )
+        manager.handleRequestSync(from: PeerID(str: "FFFFFFFFFFFFFFFF"), request: request)
+
+        try await TestHelpers.waitFor({ delegate.packets.count == 1 }, timeout: TestConstants.shortTimeout)
+        // Barrier: flush the sync queue so a late second packet would be visible.
+        manager._performMaintenanceSynchronously(now: Date())
+        let sentPackets = delegate.packets
+        #expect(sentPackets.count == 1)
+        let sent = try #require(sentPackets.first)
+        #expect(sent.type == MessageType.fragment.rawValue)
+        #expect(sent.payload.prefix(8) == wantedID)
+        #expect(sent.ttl == 0)
+        #expect(sent.isRSR)
+    }
+
+    @Test func requestMissingFragmentsSendsFilteredRequestToConnectedPeers() async throws {
+        var config = GossipSyncManager.Config()
+        config.messageSyncIntervalSeconds = 0
+        config.fragmentSyncIntervalSeconds = 0
+        config.fileTransferSyncIntervalSeconds = 0
+        let requestSyncManager = RequestSyncManager()
+        let manager = GossipSyncManager(myPeerID: myPeerID, config: config, requestSyncManager: requestSyncManager)
+        let delegate = RecordingDelegate()
+        delegate.connectedPeers = [PeerID(str: "FFFFFFFFFFFFFFFF")]
+        manager.delegate = delegate
+
+        let stalledID = try #require(Data(hexString: "0102030405060708"))
+        manager.requestMissingFragments(fragmentIDs: [stalledID])
+
+        try await TestHelpers.waitFor({ delegate.packets.count == 1 }, timeout: TestConstants.shortTimeout)
+        let sent = try #require(delegate.packets.first)
+        #expect(sent.type == MessageType.requestSync.rawValue)
+        #expect(sent.ttl == 0)
+        let request = try #require(RequestSyncPacket.decode(from: sent.payload))
+        #expect(request.types == .fragment)
+        let ids = try #require(RequestSyncPacket.decodeFragmentIdFilter(request.fragmentIdFilter))
+        #expect(ids == Set([stalledID]))
+    }
+
+    @Test func prekeyBundlesServeSyncAndSurviveStalePeerCleanup() async throws {
+        var config = GossipSyncManager.Config()
+        config.messageSyncIntervalSeconds = 0
+        config.fragmentSyncIntervalSeconds = 0
+        config.fileTransferSyncIntervalSeconds = 0
+        config.prekeyBundleSyncIntervalSeconds = 0
+        config.stalePeerCleanupIntervalSeconds = 0
+        config.stalePeerTimeoutSeconds = 5
+
+        let manager = GossipSyncManager(myPeerID: myPeerID, config: config, requestSyncManager: RequestSyncManager())
+        let delegate = RecordingDelegate()
+        manager.delegate = delegate
+
+        // Bundles are keyed by their authenticated identity (the noise static
+        // key), not the packet senderID, so the payload must be a real bundle.
+        let noiseKey = Data(repeating: 0xAB, count: 32)
+        let senderPeer = PeerID(publicKey: noiseKey)
+        let sender = try #require(Data(hexString: senderPeer.id))
+        let bundle = PrekeyBundle(
+            noiseStaticPublicKey: noiseKey,
+            prekeys: [PrekeyBundle.Prekey(id: 0, publicKey: Data(repeating: 0x11, count: 32))],
+            generatedAt: UInt64(Date().timeIntervalSince1970 * 1000),
+            signature: Data(count: PrekeyBundle.signatureLength)
+        )
+        let bundlePacket = BitchatPacket(
+            type: MessageType.prekeyBundle.rawValue,
+            senderID: sender,
+            recipientID: nil,
+            timestamp: UInt64(Date().timeIntervalSince1970 * 1000),
+            payload: try #require(bundle.encode()),
+            signature: nil,
+            ttl: 1
+        )
+        manager.onPublicPacketSeen(bundlePacket)
+        manager._performMaintenanceSynchronously(now: Date())
+        #expect(manager._hasPrekeyBundle(for: senderPeer))
+
+        // Bundles outlive the owner's announce: a leave plus stale cleanup
+        // must not drop them (they exist to reach offline owners).
+        manager.removeAnnouncementForPeer(senderPeer)
+        manager._performMaintenanceSynchronously(now: Date().addingTimeInterval(config.stalePeerTimeoutSeconds + 1))
+        #expect(manager._hasPrekeyBundle(for: senderPeer))
+
+        // And a .prekeyBundle sync request is answered with the stored packet.
+        let request = RequestSyncPacket(p: 7, m: 1, data: Data(), types: .prekeyBundle)
+        manager.handleRequestSync(from: PeerID(str: "FFFFFFFFFFFFFFFF"), request: request)
+        try await TestHelpers.waitFor({ delegate.packets.count == 1 }, timeout: TestConstants.shortTimeout)
+        let served = try #require(delegate.packets.first)
+        #expect(served.type == MessageType.prekeyBundle.rawValue)
+        #expect(served.isRSR)
+    }
+
+    @Test func prekeyBundleGossipIsKeyedByOwnerNotSenderID() {
+        // One valid bundle re-broadcast under many fabricated sender IDs must
+        // collapse to a single entry keyed by the bundle's own identity — the
+        // spray-to-exhaust-the-cap DoS produces one entry, not N.
+        let manager = GossipSyncManager(myPeerID: myPeerID, requestSyncManager: RequestSyncManager())
+        let noiseKey = Data(repeating: 0xCD, count: 32)
+        let ownerPeer = PeerID(publicKey: noiseKey)
+        let bundle = PrekeyBundle(
+            noiseStaticPublicKey: noiseKey,
+            prekeys: [PrekeyBundle.Prekey(id: 0, publicKey: Data(repeating: 0x22, count: 32))],
+            generatedAt: UInt64(Date().timeIntervalSince1970 * 1000),
+            signature: Data(count: PrekeyBundle.signatureLength)
+        )
+        guard let payload = bundle.encode() else { return }
+
+        for i in 0..<5 {
+            let fakeSender = Data((0..<8).map { j in UInt8(truncatingIfNeeded: i * 31 + j) })
+            let packet = BitchatPacket(
+                type: MessageType.prekeyBundle.rawValue,
+                senderID: fakeSender,
+                recipientID: nil,
+                timestamp: UInt64(Date().timeIntervalSince1970 * 1000) + UInt64(i),
+                payload: payload,
+                signature: nil,
+                ttl: 1
+            )
+            manager.onPublicPacketSeen(packet)
+            manager._performMaintenanceSynchronously(now: Date())
+            // No fabricated sender ID ever creates its own entry.
+            #expect(!manager._hasPrekeyBundle(for: PeerID(hexData: fakeSender)))
+        }
+        // Exactly the owner-keyed entry exists.
+        #expect(manager._hasPrekeyBundle(for: ownerPeer))
+    }
+
     // MARK: - Archive persistence
 
     @Test func publicMessagesRestoreFromArchiveAcrossRestart() async throws {
@@ -583,6 +773,7 @@ struct GossipSyncManagerTests {
 
 private final class RecordingDelegate: GossipSyncManager.Delegate {
     var onSend: (() -> Void)?
+    var connectedPeers: [PeerID] = []
     private(set) var lastPacket: BitchatPacket?
     private(set) var packets: [BitchatPacket] = []
     private let lock = NSLock()
@@ -604,6 +795,6 @@ private final class RecordingDelegate: GossipSyncManager.Delegate {
     }
     
     func getConnectedPeers() -> [PeerID] {
-        return []
+        return connectedPeers
     }
 }

bitchatTests/LocalizationCoverageTests.swift

@@ -0,0 +1,74 @@
+import Testing
+import Foundation
+
+/// Guards against locale gaps in the string catalogs: every translatable key
+/// must have a localization for every supported locale, so no user ever sees
+/// an English fallback (see PR #1391 review).
+struct LocalizationCoverageTests {
+    private static let repoRoot = URL(fileURLWithPath: #filePath)
+        .deletingLastPathComponent()  // bitchatTests
+        .deletingLastPathComponent()  // repo root
+
+    private struct Catalog {
+        let sourceLanguage: String
+        /// key -> set of locales with a localization entry
+        let coverage: [String: Set<String>]
+        /// all locales appearing anywhere in the catalog
+        var allLocales: Set<String> { coverage.values.reduce(into: []) { $0.formUnion($1) } }
+    }
+
+    private static func loadCatalog(_ relativePath: String) throws -> Catalog {
+        let url = repoRoot.appendingPathComponent(relativePath)
+        let data = try Data(contentsOf: url)
+        let root = try #require(try JSONSerialization.jsonObject(with: data) as? [String: Any])
+        let strings = try #require(root["strings"] as? [String: Any])
+        let sourceLanguage = try #require(root["sourceLanguage"] as? String)
+
+        var coverage: [String: Set<String>] = [:]
+        for (key, value) in strings {
+            guard let entry = value as? [String: Any] else { continue }
+            if entry["shouldTranslate"] as? Bool == false { continue }
+            let localizations = entry["localizations"] as? [String: Any] ?? [:]
+            var locales: Set<String> = []
+            for (locale, loc) in localizations {
+                guard let loc = loc as? [String: Any] else { continue }
+                // A localization counts if it has a non-empty stringUnit value
+                // or uses variations/substitutions (plural forms).
+                if let unit = loc["stringUnit"] as? [String: Any],
+                   let unitValue = unit["value"] as? String, !unitValue.isEmpty {
+                    locales.insert(locale)
+                } else if loc["variations"] != nil || loc["substitutions"] != nil {
+                    locales.insert(locale)
+                }
+            }
+            coverage[key] = locales
+        }
+        return Catalog(sourceLanguage: sourceLanguage, coverage: coverage)
+    }
+
+    @Test func mainCatalogCoversAllLocalesForEveryKey() throws {
+        let catalog = try Self.loadCatalog("bitchat/Localizable.xcstrings")
+        let expected = catalog.allLocales
+        #expect(expected.count > 1, "catalog should declare more locales than the source language")
+        for (key, locales) in catalog.coverage.sorted(by: { $0.key < $1.key }) {
+            let missing = expected.subtracting(locales).sorted()
+            #expect(missing.isEmpty, "\(key) is missing locales: \(missing.joined(separator: ", "))")
+        }
+    }
+
+    @Test func shareExtensionCatalogCoversAllLocalesForEveryKey() throws {
+        let catalog = try Self.loadCatalog("bitchatShareExtension/Localization/Localizable.xcstrings")
+        let expected = catalog.allLocales
+        for (key, locales) in catalog.coverage.sorted(by: { $0.key < $1.key }) {
+            let missing = expected.subtracting(locales).sorted()
+            #expect(missing.isEmpty, "\(key) is missing locales: \(missing.joined(separator: ", "))")
+        }
+    }
+
+    @Test func shareExtensionSupportsSameLocalesAsMainApp() throws {
+        let main = try Self.loadCatalog("bitchat/Localizable.xcstrings")
+        let shareExt = try Self.loadCatalog("bitchatShareExtension/Localization/Localizable.xcstrings")
+        let missing = main.allLocales.subtracting(shareExt.allLocales).sorted()
+        #expect(missing.isEmpty, "share extension is missing locales: \(missing.joined(separator: ", "))")
+    }
+}