Adjust PoW policy defaults (finalize 16/15/14 mapping)

* Screenshot privacy: warn on location sheet; gate screenshot broadcasts to chat only\n\n- Track sheet presentation in ChatViewModel\n- Show privacy alert when screenshot taken on location channels\n- Ignore screenshots for App Info and Location sheet for broadcast\n- ContentView wires sheet onAppear/onDisappear and presents alert\n- Fix location sheet subtitle wrapping: render as single Text to avoid orphaned bullets

* Fix duplicate messages after channel switch\n\n- Dedup on per-geohash append (skip if ID exists)\n- Dedup and sort timeline by timestamp when switching into a geohash\n- Keep content/layout unchanged; add lightweight debug logs for empty rows

---------

Co-authored-by: jack <jackjackbits@users.noreply.github.com>

README.md

@@ -2,59 +2,108 @@
 
 ## bitchat
 
-A decentralized peer-to-peer messaging app that works over Bluetooth mesh networks. No internet required, no servers, no phone numbers. It's the side-groupchat. 
+A decentralized peer-to-peer messaging app with dual transport architecture: local Bluetooth mesh networks for offline communication and internet-based Nostr protocol for global reach. No accounts, no phone numbers, no central servers. It's the side-groupchat.
 
 [bitchat.free](http://bitchat.free)
 
 📲 [App Store](https://apps.apple.com/us/app/bitchat-mesh/id6748219622)
 
 > [!WARNING]
-> Private messages have not received external security review and may contain vulnerabilities. Do not use for sensitive use cases, and do not rely on its security until it has been reviewed. Now uses the [Noise Protocol](http://www.noiseprotocol.org) for identity and encryption. Public local chat (the main feature) has no security concerns. 
+> Private messages have not received external security review and may contain vulnerabilities. Do not use for sensitive use cases, and do not rely on its security until it has been reviewed. Now uses the [Noise Protocol](http://www.noiseprotocol.org) for identity and encryption. Public local chat (the main feature) has no security concerns.
-
 
 ## License
 
 This project is released into the public domain. See the [LICENSE](LICENSE) file for details.
 
-
 ## Features
 
+- **Dual Transport Architecture**: Bluetooth mesh for offline + Nostr protocol for internet-based messaging
+- **Location-Based Channels**: Geographic chat rooms using geohash coordinates over global Nostr relays
+- **Intelligent Message Routing**: Automatically chooses best transport (Bluetooth → Nostr fallback)
 - **Decentralized Mesh Network**: Automatic peer discovery and multi-hop message relay over Bluetooth LE
 - **Privacy First**: No accounts, no phone numbers, no persistent identifiers
-- **Private Message End-to-End Encryption**: [Noise Protocol](http://noiseprotocol.org)
+- **Private Message End-to-End Encryption**: [Noise Protocol](http://noiseprotocol.org) for mesh, NIP-17 for Nostr
 - **IRC-Style Commands**: Familiar `/slap`, `/msg`, `/who` style interface
 - **Universal App**: Native support for iOS and macOS
 - **Emergency Wipe**: Triple-tap to instantly clear all data
 - **Performance Optimizations**: LZ4 message compression, adaptive battery modes, and optimized networking
 
-
 ## [Technical Architecture](https://deepwiki.com/permissionlesstech/bitchat)
 
-### Binary Protocol
+BitChat uses a **hybrid messaging architecture** with two complementary transport layers:
-bitchat uses an efficient binary protocol optimized for Bluetooth LE:
-- Compact packet format with 1-byte type field
-- TTL-based message routing (max 7 hops)
-- Automatic fragmentation for large messages
-- Message deduplication via unique IDs
 
-### Mesh Networking
+### Bluetooth Mesh Network (Offline)
-- Each device acts as both client and peripheral
+
-- Automatic peer discovery and connection management
+- **Local Communication**: Direct peer-to-peer within Bluetooth range
-- Adaptive duty cycling for battery optimization
+- **Multi-hop Relay**: Messages route through nearby devices (max 7 hops)
+- **No Internet Required**: Works completely offline in disaster scenarios
+- **Noise Protocol Encryption**: End-to-end encryption with forward secrecy
+- **Binary Protocol**: Compact packet format optimized for Bluetooth LE constraints
+- **Automatic Discovery**: Peer discovery and connection management
+- **Adaptive Power**: Battery-optimized duty cycling
+
+### Nostr Protocol (Internet)
+
+- **Global Reach**: Connect with users worldwide via internet relays
+- **Location Channels**: Geographic chat rooms using geohash coordinates
+- **290+ Relay Network**: Distributed across the globe for reliability
+- **NIP-17 Encryption**: Gift-wrapped private messages for internet privacy
+- **Ephemeral Keys**: Fresh cryptographic identity per geohash area
+
+### Channel Types
+
+#### `mesh #bluetooth`
+
+- **Transport**: Bluetooth Low Energy mesh network
+- **Scope**: Local devices within multi-hop range
+- **Internet**: Not required
+- **Use Case**: Offline communication, protests, disasters, remote areas
+
+#### Location Channels (`block #dr5rsj7`, `neighborhood #dr5rs`, `country #dr`)
+
+- **Transport**: Nostr protocol over internet
+- **Scope**: Geographic areas defined by geohash precision
+  - `block` (7 chars): City block level
+  - `neighborhood` (6 chars): District/neighborhood
+  - `city` (5 chars): City level
+  - `province` (4 chars): State/province
+  - `region` (2 chars): Country/large region
+- **Internet**: Required (connects to Nostr relays)
+- **Use Case**: Location-based community chat, local events, regional discussions
+
+### Direct Message Routing
+
+Private messages use **intelligent transport selection**:
+
+1. **Bluetooth First** (preferred when available)
+
+   - Direct connection with established Noise session
+   - Fastest and most private option
+
+2. **Nostr Fallback** (when Bluetooth unavailable)
+
+   - Uses recipient's Nostr public key
+   - NIP-17 gift-wrapping for privacy
+   - Routes through global relay network
+
+3. **Smart Queuing** (when neither available)
+   - Messages queued until transport becomes available
+   - Automatic delivery when connection established
 
 For detailed protocol documentation, see the [Technical Whitepaper](WHITEPAPER.md).
 
-
 ## Setup
 
 ### Option 1: Using XcodeGen (Recommended)
 
 1. Install XcodeGen if you haven't already:
+
    ```bash
    brew install xcodegen
    ```
 
 2. Generate the Xcode project:
+
    ```bash
    cd bitchat
    xcodegen generate
@@ -68,6 +117,7 @@ For detailed protocol documentation, see the [Technical Whitepaper](WHITEPAPER.m
 ### Option 2: Using Swift Package Manager
 
 1. Open the project in Xcode:
+
    ```bash
    cd bitchat
    open Package.swift
@@ -84,5 +134,5 @@ For detailed protocol documentation, see the [Technical Whitepaper](WHITEPAPER.m
 
 ### Option 4: just
 
-Want to try this on macos: `just run` will set it up and run from source. 
+Want to try this on macos: `just run` will set it up and run from source.
 Run `just clean` afterwards to restore things to original state for mobile app building and development.

bitchat.xcodeproj/project.pbxproj

@@ -7,6 +7,14 @@
 	objects = {
 
 /* Begin PBXBuildFile section */
+		04657AB52E633C6A002D5BBE /* NostrPoW.swift in Sources */ = {isa = PBXBuildFile; fileRef = 04657AB42E633C6A002D5BBE /* NostrPoW.swift */; };
+		04657AB62E633C6A002D5BBE /* NostrPoW.swift in Sources */ = {isa = PBXBuildFile; fileRef = 04657AB42E633C6A002D5BBE /* NostrPoW.swift */; };
+		04657AB82E633C76002D5BBE /* PowPolicy.swift in Sources */ = {isa = PBXBuildFile; fileRef = 04657AB72E633C76002D5BBE /* PowPolicy.swift */; };
+		04657AB92E633C76002D5BBE /* PowPolicy.swift in Sources */ = {isa = PBXBuildFile; fileRef = 04657AB72E633C76002D5BBE /* PowPolicy.swift */; };
+		04657ABB2E633C94002D5BBE /* MiningAnimation.swift in Sources */ = {isa = PBXBuildFile; fileRef = 04657ABA2E633C94002D5BBE /* MiningAnimation.swift */; };
+		04657ABC2E633C94002D5BBE /* MiningAnimation.swift in Sources */ = {isa = PBXBuildFile; fileRef = 04657ABA2E633C94002D5BBE /* MiningAnimation.swift */; };
+		04657ABE2E633CA4002D5BBE /* NostrPoWTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 04657ABD2E633CA4002D5BBE /* NostrPoWTests.swift */; };
+		04657ABF2E633CA4002D5BBE /* NostrPoWTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 04657ABD2E633CA4002D5BBE /* NostrPoWTests.swift */; };
 		047502802E53A0FC0083520F /* FragmentationTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 0475027E2E53A0FC0083520F /* FragmentationTests.swift */; };
 		047502812E53A0FC0083520F /* FragmentationTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 0475027E2E53A0FC0083520F /* FragmentationTests.swift */; };
 		047502872E5416250083520F /* Geohash.swift in Sources */ = {isa = PBXBuildFile; fileRef = 047502852E5416250083520F /* Geohash.swift */; };
@@ -32,6 +40,10 @@
 		048A4BE72E5CCCC300162C4A /* TransportConfig.swift in Sources */ = {isa = PBXBuildFile; fileRef = 048A4BE62E5CCCC300162C4A /* TransportConfig.swift */; };
 		048A4BE82E5CCCC300162C4A /* TransportConfig.swift in Sources */ = {isa = PBXBuildFile; fileRef = 048A4BE62E5CCCC300162C4A /* TransportConfig.swift */; };
 		048A4BE92E5CCCC300162C4B /* TransportConfig.swift in Sources */ = {isa = PBXBuildFile; fileRef = 048A4BE62E5CCCC300162C4A /* TransportConfig.swift */; };
+		048A4C282E5FCD6600162C4A /* GeohashBookmarksStore.swift in Sources */ = {isa = PBXBuildFile; fileRef = 048A4C272E5FCD6600162C4A /* GeohashBookmarksStore.swift */; };
+		048A4C292E5FCD6600162C4A /* GeohashBookmarksStore.swift in Sources */ = {isa = PBXBuildFile; fileRef = 048A4C272E5FCD6600162C4A /* GeohashBookmarksStore.swift */; };
+		048A4C2B2E5FCE0300162C4A /* GeohashBookmarksStoreTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 048A4C2A2E5FCE0300162C4A /* GeohashBookmarksStoreTests.swift */; };
+		048A4C2C2E5FCE0300162C4A /* GeohashBookmarksStoreTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 048A4C2A2E5FCE0300162C4A /* GeohashBookmarksStoreTests.swift */; };
 		049BD3902E4EC4F0001A566B /* PrivateChatManager.swift in Sources */ = {isa = PBXBuildFile; fileRef = 049BD38F2E4EC4F0001A566B /* PrivateChatManager.swift */; };
 		049BD3912E4EC4F0001A566B /* AutocompleteService.swift in Sources */ = {isa = PBXBuildFile; fileRef = 049BD38C2E4EC4F0001A566B /* AutocompleteService.swift */; };
 		049BD3922E4EC4F0001A566B /* CommandProcessor.swift in Sources */ = {isa = PBXBuildFile; fileRef = 049BD38D2E4EC4F0001A566B /* CommandProcessor.swift */; };
@@ -193,6 +205,10 @@
 
 /* Begin PBXFileReference section */
 		03C57F452B55FD0FD8F51421 /* bitchatTests_macOS.xctest */ = {isa = PBXFileReference; explicitFileType = wrapper.cfbundle; includeInIndex = 0; path = bitchatTests_macOS.xctest; sourceTree = BUILT_PRODUCTS_DIR; };
+		04657AB42E633C6A002D5BBE /* NostrPoW.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = NostrPoW.swift; sourceTree = "<group>"; };
+		04657AB72E633C76002D5BBE /* PowPolicy.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PowPolicy.swift; sourceTree = "<group>"; };
+		04657ABA2E633C94002D5BBE /* MiningAnimation.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MiningAnimation.swift; sourceTree = "<group>"; };
+		04657ABD2E633CA4002D5BBE /* NostrPoWTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = NostrPoWTests.swift; sourceTree = "<group>"; };
 		0475027E2E53A0FC0083520F /* FragmentationTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = FragmentationTests.swift; sourceTree = "<group>"; };
 		047502852E5416250083520F /* Geohash.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Geohash.swift; sourceTree = "<group>"; };
 		047502862E5416250083520F /* LocationChannel.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = LocationChannel.swift; sourceTree = "<group>"; };
@@ -205,6 +221,8 @@
 		047502B32E55FED60083520F /* MeshPeerList.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MeshPeerList.swift; sourceTree = "<group>"; };
 		047502B82E560F690083520F /* RelayController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = RelayController.swift; sourceTree = "<group>"; };
 		048A4BE62E5CCCC300162C4A /* TransportConfig.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = TransportConfig.swift; sourceTree = "<group>"; };
+		048A4C272E5FCD6600162C4A /* GeohashBookmarksStore.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = GeohashBookmarksStore.swift; sourceTree = "<group>"; };
+		048A4C2A2E5FCE0300162C4A /* GeohashBookmarksStoreTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = GeohashBookmarksStoreTests.swift; sourceTree = "<group>"; };
 		049BD38C2E4EC4F0001A566B /* AutocompleteService.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AutocompleteService.swift; sourceTree = "<group>"; };
 		049BD38D2E4EC4F0001A566B /* CommandProcessor.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CommandProcessor.swift; sourceTree = "<group>"; };
 		049BD38F2E4EC4F0001A566B /* PrivateChatManager.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PrivateChatManager.swift; sourceTree = "<group>"; };
@@ -445,6 +463,7 @@
 		A55126E93155456CAA8D6656 /* Views */ = {
 			isa = PBXGroup;
 			children = (
+				04657ABA2E633C94002D5BBE /* MiningAnimation.swift */,
 				AA77BB13CC22DD33EE44FF57 /* VerificationViews.swift */,
 				047502B22E55FED60083520F /* GeohashPeopleList.swift */,
 				047502B32E55FED60083520F /* MeshPeerList.swift */,
@@ -484,6 +503,8 @@
 			isa = PBXGroup;
 			children = (
 				D69A18D27F9A565FD6041E12 /* Info.plist */,
+				04657ABD2E633CA4002D5BBE /* NostrPoWTests.swift */,
+				048A4C2A2E5FCE0300162C4A /* GeohashBookmarksStoreTests.swift */,
 				047502912E547ACC0083520F /* LocationChannelsTests.swift */,
 				C272F137CE00FC5A96E0CC06 /* NostrProtocolTests.swift */,
 				980B109CBA72BC996455C62B /* BLEServiceTests.swift */,
@@ -519,6 +540,8 @@
 		D98A3186D7E4C72E35BDF7FE /* Services */ = {
 			isa = PBXGroup;
 			children = (
+				04657AB72E633C76002D5BBE /* PowPolicy.swift */,
+				048A4C272E5FCD6600162C4A /* GeohashBookmarksStore.swift */,
 				048A4BE62E5CCCC300162C4A /* TransportConfig.swift */,
 				AA77BB10CC22DD33EE44FF55 /* VerificationService.swift */,
 				047502B82E560F690083520F /* RelayController.swift */,
@@ -542,6 +565,7 @@
 		E78C7F4B6769C0A72F5DE544 /* Nostr */ = {
 			isa = PBXGroup;
 			children = (
+				04657AB42E633C6A002D5BBE /* NostrPoW.swift */,
 				A1B2C3D44E5F60718293A4B4 /* XChaCha20Poly1305Compat.swift */,
 				049BD39B2E51DBD9001A566B /* NostrEmbeddedBitChat.swift */,
 				5F8043995007F0D84438EDD9 /* NostrIdentity.swift */,
@@ -771,6 +795,7 @@
 				0475028C2E54171C0083520F /* LocationChannelManager.swift in Sources */,
 				AFF33EF44626EF0579D17EB1 /* NoiseHandshakeCoordinator.swift in Sources */,
 				8C1AB0F2D48207E0755DA91A /* NoiseProtocol.swift in Sources */,
+				048A4C282E5FCD6600162C4A /* GeohashBookmarksStore.swift in Sources */,
 				049BD3AC2E51E38E001A566B /* PeerIDResolver.swift in Sources */,
 				D691938B4029A04CC905FDC8 /* NoiseSecurityConsiderations.swift in Sources */,
 				8A14ADADF5CD7A79919CB655 /* NoiseSession.swift in Sources */,
@@ -783,15 +808,18 @@
 				749D8CF8A362B6CD0786782D /* NotificationService.swift in Sources */,
 				049BD3AF2E51ED60001A566B /* Transport.swift in Sources */,
 				E2DCF7817344F1CCDB8B7B2F /* SecureIdentityStateManager.swift in Sources */,
+				04657ABC2E633C94002D5BBE /* MiningAnimation.swift in Sources */,
 				049BD3A02E51DBF4001A566B /* Packets.swift in Sources */,
 				047502892E5416250083520F /* Geohash.swift in Sources */,
 				0475028A2E5416250083520F /* LocationChannel.swift in Sources */,
+				04657AB82E633C76002D5BBE /* PowPolicy.swift in Sources */,
 				049BD3A12E51DBF4001A566B /* PeerID.swift in Sources */,
 				049BD3942E4EC4F0001A566B /* PrivateChatManager.swift in Sources */,
 				049BD3952E4EC4F0001A566B /* AutocompleteService.swift in Sources */,
 				049BD3962E4EC4F0001A566B /* CommandProcessor.swift in Sources */,
 				D111988977C3BC246AB27FA4 /* SecureLogger.swift in Sources */,
 				8DE687D2EB5EB120868DBFB5 /* BLEService.swift in Sources */,
+				04657AB52E633C6A002D5BBE /* NostrPoW.swift in Sources */,
 				AA11BB22CC33DD44EE55FF66 /* MessageTextHelpers.swift in Sources */,
 				E0A1B2C3D4E5F6012345678B /* GeoRelayDirectory.swift in Sources */,
 			);
@@ -830,6 +858,7 @@
 				0475028D2E54171C0083520F /* LocationChannelManager.swift in Sources */,
 				6D0D4A0B1D8B659DCBAE7C9C /* NoiseHandshakeCoordinator.swift in Sources */,
 				A7187D48B07C6857DE01D0ED /* NoiseProtocol.swift in Sources */,
+				048A4C292E5FCD6600162C4A /* GeohashBookmarksStore.swift in Sources */,
 				049BD3AB2E51E38E001A566B /* PeerIDResolver.swift in Sources */,
 				9CCF09F7527EC681A13FC246 /* NoiseSecurityConsiderations.swift in Sources */,
 				92D1CF17DF88EA298F6E5E8E /* NoiseSession.swift in Sources */,
@@ -842,15 +871,18 @@
 				61C81ED5F679D5E973EE0C07 /* NotificationService.swift in Sources */,
 				049BD3AE2E51ED60001A566B /* Transport.swift in Sources */,
 				68C4BE564735F6E7915274A2 /* SecureIdentityStateManager.swift in Sources */,
+				04657ABB2E633C94002D5BBE /* MiningAnimation.swift in Sources */,
 				049BD3A22E51DBF4001A566B /* Packets.swift in Sources */,
 				047502872E5416250083520F /* Geohash.swift in Sources */,
 				047502882E5416250083520F /* LocationChannel.swift in Sources */,
+				04657AB92E633C76002D5BBE /* PowPolicy.swift in Sources */,
 				049BD3A32E51DBF4001A566B /* PeerID.swift in Sources */,
 				049BD3902E4EC4F0001A566B /* PrivateChatManager.swift in Sources */,
 				049BD3912E4EC4F0001A566B /* AutocompleteService.swift in Sources */,
 				049BD3922E4EC4F0001A566B /* CommandProcessor.swift in Sources */,
 				EC5241969D2550B97629EBD0 /* SecureLogger.swift in Sources */,
 				C165DD35BB8E9C327A3C2DA4 /* BLEService.swift in Sources */,
+				04657AB62E633C6A002D5BBE /* NostrPoW.swift in Sources */,
 				AA11BB22CC33DD44EE55FF67 /* MessageTextHelpers.swift in Sources */,
 				E0A1B2C3D4E5F6012345678C /* GeoRelayDirectory.swift in Sources */,
 			);
@@ -865,7 +897,9 @@
 				8F282E9CCA5AE1ECC001D2E4 /* IntegrationTests.swift in Sources */,
 				047502B12E55E8450083520F /* InputValidatorTests.swift in Sources */,
 				D727EA273CB214FC32612469 /* MockBluetoothMeshService.swift in Sources */,
+				04657ABF2E633CA4002D5BBE /* NostrPoWTests.swift in Sources */,
 				047502932E547ACC0083520F /* LocationChannelsTests.swift in Sources */,
+				048A4C2B2E5FCE0300162C4A /* GeohashBookmarksStoreTests.swift in Sources */,
 				6C803BF930E7E19BE6E99EAA /* MockBLEService.swift in Sources */,
 				765254F56997F01054699AC0 /* NoiseProtocolTests.swift in Sources */,
 				968181D255CA7A804340B4DA /* NostrProtocolTests.swift in Sources */,
@@ -887,7 +921,9 @@
 				686441ABC2AF83EE98E6ECF2 /* IntegrationTests.swift in Sources */,
 				047502B02E55E8450083520F /* InputValidatorTests.swift in Sources */,
 				8851F08D88C5B1DE7B9F55C6 /* MockBluetoothMeshService.swift in Sources */,
+				04657ABE2E633CA4002D5BBE /* NostrPoWTests.swift in Sources */,
 				047502922E547ACC0083520F /* LocationChannelsTests.swift in Sources */,
+				048A4C2C2E5FCE0300162C4A /* GeohashBookmarksStoreTests.swift in Sources */,
 				3849CA6D99B2D536636DF4A6 /* MockBLEService.swift in Sources */,
 				BC4DC75F4FB823FF40569676 /* NoiseProtocolTests.swift in Sources */,
 				EE8C3ECADAB3083A2687D50B /* NostrProtocolTests.swift in Sources */,

bitchat/Nostr/NostrPoW.swift

@@ -0,0 +1,96 @@
+import Foundation
+import CryptoKit
+import Security
+import Darwin
+
+/// NIP-13 Proof-of-Work utilities for Nostr events.
+/// - Counts leading zero bits and mines a nonce tag to meet a target.
+enum NostrPoW {
+    /// Table of leading zero bit counts for all 256 byte values.
+    private static let lzTable: [UInt8] = {
+        (0...255).map { v -> UInt8 in
+            var x = UInt8(v)
+            if x == 0 { return 8 }
+            var n: UInt8 = 0
+            while (x & 0x80) == 0 {
+                n &+= 1
+                x <<= 1
+            }
+            return n
+        }
+    }()
+
+    /// Count leading zero bits in a 32-byte hash.
+    static func leadingZeroBits(_ data: Data) -> Int {
+        var total = 0
+        for b in data {
+            let lz = Int(lzTable[Int(b)])
+            total += lz
+            if lz != 8 { break }
+        }
+        return total
+    }
+
+    /// Compute Nostr event id hash (SHA-256 over canonical serialization) for given fields.
+    private static func eventIDHash(pubkey: String, createdAt: Int, kind: Int, tags: [[String]], content: String) -> (hex: String, data: Data) {
+        let serialized: [Any] = [0, pubkey, createdAt, kind, tags, content]
+        let json = try! JSONSerialization.data(withJSONObject: serialized, options: [.withoutEscapingSlashes])
+        let digest = SHA256.hash(data: json)
+        let data = Data(digest)
+        let hex = data.map { String(format: "%02x", $0) }.joined()
+        return (hex, data)
+    }
+
+    /// Mine a NIP-13 nonce tag that satisfies the target leading-zero bits.
+    /// - Parameters:
+    ///   - pubkey: x-only hex pubkey (64-hex chars)
+    ///   - createdAt: seconds since epoch
+    ///   - kind: event kind
+    ///   - baseTags: existing tags (e.g., [ ["g", geohash], ["n", nickname], ... ])
+    ///   - content: event content
+    ///   - targetBits: required leading zero bits
+    ///   - startNonce: optional starting nonce (random if nil)
+    /// - Returns: (nonce, idHex)
+    static func mine(pubkey: String,
+                     createdAt: Int,
+                     kind: Int,
+                     baseTags: [[String]],
+                     content: String,
+                     targetBits: Int,
+                     startNonce: UInt64? = nil) -> (nonce: UInt64, idHex: String) {
+        var nonce: UInt64 = startNonce ?? randomNonce()
+        // Build a local tags buffer once to avoid reallocating unrelated tags
+        var tags = baseTags
+        tags.append(["nonce", "0", String(targetBits)])
+
+        var iter: UInt64 = 0
+        while true {
+            var solved = false
+            var idHexOut = ""
+            // Use an autorelease pool periodically to keep memory stable on iOS
+            autoreleasepool {
+                // Update nonce tag value (second element)
+                tags[tags.count - 1][1] = String(nonce)
+                let (idHex, idData) = eventIDHash(pubkey: pubkey, createdAt: createdAt, kind: kind, tags: tags, content: content)
+                if leadingZeroBits(idData) >= targetBits {
+                    solved = true
+                    idHexOut = idHex
+                }
+            }
+            if solved {
+                return (nonce, idHexOut)
+            }
+            nonce &+= 1
+            iter &+= 1
+            if iter & 0x3FFF == 0 { /* yield every ~16k iterations */ _ = sched_yield() }
+        }
+    }
+
+    private static func randomNonce() -> UInt64 {
+        var n: UInt64 = 0
+        withUnsafeMutableBytes(of: &n) { ptr in
+            _ = SecRandomCopyBytes(kSecRandomDefault, ptr.count, ptr.baseAddress!)
+        }
+        return n
+    }
+}

bitchat/Protocols/BitchatProtocol.swift

@@ -409,6 +409,8 @@ class BitchatMessage: Codable {
     let senderPeerID: String?
     let mentions: [String]?  // Array of mentioned nicknames
     var deliveryStatus: DeliveryStatus? // Delivery tracking
+    // Mining state for Nostr geohash PoW (UI hint: hide timestamp, animate)
+    var isMiningPow: Bool? // default nil/false
     
     // Cached formatted text (not included in Codable)
     private var _cachedFormattedText: [String: AttributedString] = [:]
@@ -421,13 +423,18 @@ class BitchatMessage: Codable {
         _cachedFormattedText["\(isDark)-\(isSelf)"] = text
     }
     
+    func clearCachedFormattedText() {
+        _cachedFormattedText.removeAll()
+    }
+    
     // Codable implementation
     enum CodingKeys: String, CodingKey {
         case id, sender, content, timestamp, isRelay, originalSender
         case isPrivate, recipientNickname, senderPeerID, mentions, deliveryStatus
+        case isMiningPow
     }
     
-    init(id: String? = nil, sender: String, content: String, timestamp: Date, isRelay: Bool, originalSender: String? = nil, isPrivate: Bool = false, recipientNickname: String? = nil, senderPeerID: String? = nil, mentions: [String]? = nil, deliveryStatus: DeliveryStatus? = nil) {
+    init(id: String? = nil, sender: String, content: String, timestamp: Date, isRelay: Bool, originalSender: String? = nil, isPrivate: Bool = false, recipientNickname: String? = nil, senderPeerID: String? = nil, mentions: [String]? = nil, deliveryStatus: DeliveryStatus? = nil, isMiningPow: Bool? = nil) {
         self.id = id ?? UUID().uuidString
         self.sender = sender
         self.content = content
@@ -439,6 +446,7 @@ class BitchatMessage: Codable {
         self.senderPeerID = senderPeerID
         self.mentions = mentions
         self.deliveryStatus = deliveryStatus ?? (isPrivate ? .sending : nil)
+        self.isMiningPow = isMiningPow
     }
 }
 
@@ -455,7 +463,8 @@ extension BitchatMessage: Equatable {
                lhs.recipientNickname == rhs.recipientNickname &&
                lhs.senderPeerID == rhs.senderPeerID &&
                lhs.mentions == rhs.mentions &&
-               lhs.deliveryStatus == rhs.deliveryStatus
+               lhs.deliveryStatus == rhs.deliveryStatus &&
+               (lhs.isMiningPow ?? false) == (rhs.isMiningPow ?? false)
     }
 }
 

bitchat/Protocols/Geohash.swift

@@ -87,4 +87,28 @@ enum Geohash {
         let lon = (lonInterval.0 + lonInterval.1) / 2
         return (lat, lon)
     }
+
+    /// Decodes a geohash into its latitude and longitude bounds.
+    /// - Parameter geohash: Base32 geohash string.
+    /// - Returns: (latMin, latMax, lonMin, lonMax)
+    static func decodeBounds(_ geohash: String) -> (latMin: Double, latMax: Double, lonMin: Double, lonMax: Double) {
+        var latInterval: (Double, Double) = (-90.0, 90.0)
+        var lonInterval: (Double, Double) = (-180.0, 180.0)
+
+        var isEven = true
+        for ch in geohash.lowercased() {
+            guard let cd = base32Map[ch] else { continue }
+            for mask in [16, 8, 4, 2, 1] {
+                if isEven {
+                    let mid = (lonInterval.0 + lonInterval.1) / 2
+                    if (cd & mask) != 0 { lonInterval.0 = mid } else { lonInterval.1 = mid }
+                } else {
+                    let mid = (latInterval.0 + latInterval.1) / 2
+                    if (cd & mask) != 0 { latInterval.0 = mid } else { latInterval.1 = mid }
+                }
+                isEven.toggle()
+            }
+        }
+        return (latInterval.0, latInterval.1, lonInterval.0, lonInterval.1)
+    }
 }

bitchat/Services/GeohashBookmarksStore.swift

@@ -0,0 +1,227 @@
+import Foundation
+import Combine
+#if os(iOS) || os(macOS)
+import CoreLocation
+#endif
+
+/// Stores a user-maintained list of bookmarked geohash channels.
+/// - Persistence: UserDefaults (JSON string array)
+/// - Semantics: geohashes are normalized to lowercase base32 and de-duplicated
+final class GeohashBookmarksStore: ObservableObject {
+    static let shared = GeohashBookmarksStore()
+
+    @Published private(set) var bookmarks: [String] = []
+    @Published private(set) var bookmarkNames: [String: String] = [:] // geohash -> friendly name
+
+    private let storeKey = "locationChannel.bookmarks"
+    private let namesStoreKey = "locationChannel.bookmarkNames"
+    private var membership: Set<String> = []
+    #if os(iOS) || os(macOS)
+    private let geocoder = CLGeocoder()
+    private var resolving: Set<String> = []
+    #endif
+
+    private init() {
+        load()
+    }
+
+    // MARK: - Public API
+    func isBookmarked(_ geohash: String) -> Bool {
+        return membership.contains(Self.normalize(geohash))
+    }
+
+    func toggle(_ geohash: String) {
+        let gh = Self.normalize(geohash)
+        if membership.contains(gh) {
+            remove(gh)
+        } else {
+            add(gh)
+        }
+    }
+
+    func add(_ geohash: String) {
+        let gh = Self.normalize(geohash)
+        guard !gh.isEmpty else { return }
+        guard !membership.contains(gh) else { return }
+        bookmarks.insert(gh, at: 0)
+        membership.insert(gh)
+        persist()
+        // Resolve and persist a friendly name once when added
+        resolveNameIfNeeded(for: gh)
+    }
+
+    func remove(_ geohash: String) {
+        let gh = Self.normalize(geohash)
+        guard membership.contains(gh) else { return }
+        if let idx = bookmarks.firstIndex(of: gh) { bookmarks.remove(at: idx) }
+        membership.remove(gh)
+        // Clean up stored name to avoid stale cache growth
+        if bookmarkNames.removeValue(forKey: gh) != nil {
+            persistNames()
+        }
+        persist()
+    }
+
+    // MARK: - Persistence
+    private func load() {
+        guard let data = UserDefaults.standard.data(forKey: storeKey) else { return }
+        if let arr = try? JSONDecoder().decode([String].self, from: data) {
+            // Sanitize, normalize, dedupe while preserving order (first occurrence wins)
+            var seen = Set<String>()
+            var list: [String] = []
+            for raw in arr {
+                let gh = Self.normalize(raw)
+                guard !gh.isEmpty else { continue }
+                if !seen.contains(gh) {
+                    seen.insert(gh)
+                    list.append(gh)
+                }
+            }
+            bookmarks = list
+            membership = seen
+        }
+        // Load any saved names
+        if let namesData = UserDefaults.standard.data(forKey: namesStoreKey),
+           let dict = try? JSONDecoder().decode([String: String].self, from: namesData) {
+            bookmarkNames = dict
+        }
+    }
+
+    private func persist() {
+        if let data = try? JSONEncoder().encode(bookmarks) {
+            UserDefaults.standard.set(data, forKey: storeKey)
+        }
+    }
+
+    private func persistNames() {
+        if let data = try? JSONEncoder().encode(bookmarkNames) {
+            UserDefaults.standard.set(data, forKey: namesStoreKey)
+        }
+    }
+
+    // MARK: - Helpers
+    private static func normalize(_ s: String) -> String {
+        let allowed = Set("0123456789bcdefghjkmnpqrstuvwxyz")
+        return s
+            .trimmingCharacters(in: .whitespacesAndNewlines)
+            .lowercased()
+            .replacingOccurrences(of: "#", with: "")
+            .filter { allowed.contains($0) }
+    }
+
+    // MARK: - Name Resolution
+    /// Attempt to resolve and persist a friendly place name for a bookmarked geohash.
+    func resolveNameIfNeeded(for geohash: String) {
+        let gh = Self.normalize(geohash)
+        guard !gh.isEmpty else { return }
+        if bookmarkNames[gh] != nil { return }
+        #if os(iOS) || os(macOS)
+        if resolving.contains(gh) { return }
+        resolving.insert(gh)
+        // For very coarse geohashes, sample multiple points to capture multiple admin areas
+        if gh.count <= 2 {
+            let b = Geohash.decodeBounds(gh)
+            let pts: [CLLocation] = [
+                CLLocation(latitude: (b.latMin + b.latMax) / 2, longitude: (b.lonMin + b.lonMax) / 2), // center
+                CLLocation(latitude: b.latMin, longitude: b.lonMin),
+                CLLocation(latitude: b.latMin, longitude: b.lonMax),
+                CLLocation(latitude: b.latMax, longitude: b.lonMin),
+                CLLocation(latitude: b.latMax, longitude: b.lonMax)
+            ]
+            resolveCompositeAdminName(geohash: gh, points: pts)
+        } else {
+            let center = Geohash.decodeCenter(gh)
+            let loc = CLLocation(latitude: center.lat, longitude: center.lon)
+            geocoder.reverseGeocodeLocation(loc) { [weak self] placemarks, _ in
+                guard let self = self else { return }
+                defer { self.resolving.remove(gh) }
+                if let pm = placemarks?.first {
+                    let name = Self.nameForGeohashLength(gh.count, from: pm)
+                    if let name = name, !name.isEmpty {
+                        DispatchQueue.main.async {
+                            self.bookmarkNames[gh] = name
+                            self.persistNames()
+                        }
+                    }
+                }
+            }
+        }
+        #endif
+    }
+
+    #if os(iOS) || os(macOS)
+    private func resolveCompositeAdminName(geohash gh: String, points: [CLLocation]) {
+        var uniqueAdmins = OrderedSet<String>()
+        var idx = 0
+        func step() {
+            if idx >= points.count {
+                // Compose up to 2 names joined by ' and '
+                let finalName: String? = {
+                    let names = uniqueAdmins.array
+                    if names.count >= 2 { return names[0] + " and " + names[1] }
+                    return names.first
+                }()
+                if let finalName = finalName, !finalName.isEmpty {
+                    DispatchQueue.main.async {
+                        self.bookmarkNames[gh] = finalName
+                        self.persistNames()
+                    }
+                }
+                self.resolving.remove(gh)
+                return
+            }
+            let loc = points[idx]
+            idx += 1
+            geocoder.reverseGeocodeLocation(loc) { [weak self] placemarks, _ in
+                guard self != nil else { return }
+                if let pm = placemarks?.first {
+                    if let admin = pm.administrativeArea, !admin.isEmpty {
+                        uniqueAdmins.insert(admin)
+                    } else if let country = pm.country, !country.isEmpty {
+                        uniqueAdmins.insert(country)
+                    }
+                }
+                // Proceed to next point
+                step()
+            }
+        }
+        step()
+    }
+
+    // Minimal ordered-set for stable joining
+    private struct OrderedSet<Element: Hashable> {
+        private var set: Set<Element> = []
+        private(set) var array: [Element] = []
+        mutating func insert(_ element: Element) {
+            if set.insert(element).inserted { array.append(element) }
+        }
+    }
+
+    private static func nameForGeohashLength(_ len: Int, from pm: CLPlacemark) -> String? {
+        switch len {
+        case 0...2:
+            // Prefer administrative area if available at this coarse level
+            return pm.administrativeArea ?? pm.country
+        case 3...4:
+            return pm.administrativeArea ?? pm.subAdministrativeArea ?? pm.country
+        case 5:
+            return pm.locality ?? pm.subAdministrativeArea ?? pm.administrativeArea
+        case 6...7:
+            return pm.subLocality ?? pm.locality ?? pm.administrativeArea
+        default:
+            return pm.subLocality ?? pm.locality ?? pm.administrativeArea ?? pm.country
+        }
+    }
+    #endif
+
+    #if DEBUG
+    /// Testing-only reset helper
+    func _resetForTesting() {
+        bookmarks.removeAll()
+        membership.removeAll()
+        bookmarkNames.removeAll()
+        persist()
+        persistNames()
+    }
+    #endif
+}

bitchat/Services/LocationChannelManager.swift

@@ -50,10 +50,8 @@ final class LocationChannelManager: NSObject, CLLocationManagerDelegate, Observa
            let arr = try? JSONDecoder().decode([String].self, from: data) {
             teleportedSet = Set(arr)
         }
-        // Initialize teleported flag from persisted state if a location channel is selected
+        // Do not eagerly mark teleported on startup; wait for location to compute regional set.
-        if case .location(let ch) = selectedChannel {
+        // This avoids showing teleported for in-region channels during cold start.
-            teleported = teleportedSet.contains(ch.geohash)
-        }
         let status: CLAuthorizationStatus
         if #available(iOS 14.0, macOS 11.0, *) {
             status = cl.authorizationStatus
@@ -61,6 +59,15 @@ final class LocationChannelManager: NSObject, CLLocationManagerDelegate, Observa
             status = CLLocationManager.authorizationStatus()
         }
         updatePermissionState(from: status)
+        // If we don't have location authorization at startup, fall back to persisted teleport state
+        switch status {
+        case .authorizedAlways, .authorizedWhenInUse, .authorized:
+            break // will compute from location
+        default:
+            if case .location(let ch) = selectedChannel {
+                teleported = teleportedSet.contains(ch.geohash)
+            }
+        }
     }
 
     // MARK: - Public API
@@ -129,7 +136,21 @@ final class LocationChannelManager: NSObject, CLLocationManagerDelegate, Observa
             case .mesh:
                 self.teleported = false
             case .location(let ch):
-                self.teleported = self.teleportedSet.contains(ch.geohash)
+                // If this geohash is in our current regional set, do NOT mark teleported.
+                let inRegional = self.availableChannels.contains { $0.geohash == ch.geohash }
+                if inRegional {
+                    self.teleported = false
+                    // Clear persisted teleport for this geohash to keep future selections clean
+                    if self.teleportedSet.contains(ch.geohash) {
+                        self.teleportedSet.remove(ch.geohash)
+                        if let data = try? JSONEncoder().encode(Array(self.teleportedSet)) {
+                            UserDefaults.standard.set(data, forKey: self.teleportedStoreKey)
+                        }
+                    }
+                } else {
+                    // Fall back to persisted mark (set by deep link or manual teleport)
+                    self.teleported = self.teleportedSet.contains(ch.geohash)
+                }
             }
         }
     }
@@ -202,14 +223,25 @@ final class LocationChannelManager: NSObject, CLLocationManagerDelegate, Observa
         }
         Task { @MainActor in
             self.availableChannels = result
-            // Recompute teleported status based on persisted state OR current location vs selected channel
+            // Recompute teleported status based on whether the selected geohash is in our regional set
             switch self.selectedChannel {
             case .mesh:
                 self.teleported = false
             case .location(let ch):
-                let persisted = self.teleportedSet.contains(ch.geohash)
+                // Membership check using freshly computed regional channels; avoids precision/rename drift
-                let currentGH = Geohash.encode(latitude: coord.latitude, longitude: coord.longitude, precision: ch.level.precision)
+                let inRegional = result.contains { $0.geohash == ch.geohash }
-                self.teleported = persisted || (currentGH != ch.geohash)
+                if inRegional {
+                    self.teleported = false
+                    // Clear persisted teleport flag if present
+                    if self.teleportedSet.contains(ch.geohash) {
+                        self.teleportedSet.remove(ch.geohash)
+                        if let data = try? JSONEncoder().encode(Array(self.teleportedSet)) {
+                            UserDefaults.standard.set(data, forKey: self.teleportedStoreKey)
+                        }
+                    }
+                } else {
+                    self.teleported = true
+                }
             }
         }
     }

bitchat/Services/PowPolicy.swift

@@ -0,0 +1,17 @@
+import Foundation
+
+/// Simple default policy for NIP-13 difficulty on geohash chats.
+/// Progressive by geohash precision; adjustable later by live activity.
+enum PowPolicy {
+    /// Determine target bits for a given geohash string.
+    /// Clamped to a sane range to keep UX responsive on phones.
+    static func requiredBits(forGeohash geohash: String) -> Int {
+        let precision = geohash.count
+        // Start at 13 and go down with higher precision (smaller areas)
+        switch precision {
+        case ...5: return 16
+        case 6:    return 15
+        default:   return 14
+        }
+    }
+}

bitchat/ViewModels/ChatViewModel.swift

@@ -382,6 +382,11 @@ class ChatViewModel: ObservableObject, BitchatDelegate {
     @Published var showBluetoothAlert = false
     @Published var bluetoothAlertMessage = ""
     @Published var bluetoothState: CBManagerState = .unknown
+
+    // Presentation state for privacy gating
+    @Published var isLocationChannelsSheetPresented: Bool = false
+    @Published var isAppInfoPresented: Bool = false
+    @Published var showScreenshotPrivacyWarning: Bool = false
     
     // Messages are naturally ephemeral - no persistent storage
     // Persist mesh public timeline across channel switches
@@ -586,6 +591,11 @@ class ChatViewModel: ObservableObject, BitchatDelegate {
                         if connected {
                             Task { @MainActor in
                                 self.resubscribeCurrentGeohash()
+                                // Re-init sampling for regional + bookmarked geohashes after reconnect
+                                let regional = LocationChannelManager.shared.availableChannels.map { $0.geohash }
+                                let bookmarks = GeohashBookmarksStore.shared.bookmarks
+                                let union = Array(Set(regional).union(bookmarks))
+                                self.beginGeohashSampling(for: union)
                             }
                         }
                     }
@@ -611,21 +621,41 @@ class ChatViewModel: ObservableObject, BitchatDelegate {
             self.switchLocationChannel(to: LocationChannelManager.shared.selectedChannel)
         }
 
-        // Background: keep sampling nearby geohashes for notifications even when sheet is closed
+        // Background: keep sampling nearby geohashes + bookmarks for notifications even when sheet is closed
         LocationChannelManager.shared.$availableChannels
             .receive(on: DispatchQueue.main)
             .sink { [weak self] channels in
                 guard let self = self else { return }
-                let ghs = channels.map { $0.geohash }
+                let regional = channels.map { $0.geohash }
+                let bookmarks = GeohashBookmarksStore.shared.bookmarks
+                let union = Array(Set(regional).union(bookmarks))
                 Task { @MainActor in
-                    self.beginGeohashSampling(for: ghs)
+                    self.beginGeohashSampling(for: union)
                 }
             }
             .store(in: &cancellables)
-        // Kick off initial sampling if we already have channels
+
-        if !LocationChannelManager.shared.availableChannels.isEmpty {
+        // Also observe bookmark changes to update sampling
-            let ghs = LocationChannelManager.shared.availableChannels.map { $0.geohash }
+        GeohashBookmarksStore.shared.$bookmarks
-            Task { @MainActor in self.beginGeohashSampling(for: ghs) }
+            .receive(on: DispatchQueue.main)
+            .sink { [weak self] bookmarks in
+                guard let self = self else { return }
+                let regional = LocationChannelManager.shared.availableChannels.map { $0.geohash }
+                let union = Array(Set(regional).union(bookmarks))
+                Task { @MainActor in
+                    self.beginGeohashSampling(for: union)
+                }
+            }
+            .store(in: &cancellables)
+
+        // Kick off initial sampling if we have regional channels or bookmarks
+        do {
+            let regional = LocationChannelManager.shared.availableChannels.map { $0.geohash }
+            let bookmarks = GeohashBookmarksStore.shared.bookmarks
+            let union = Array(Set(regional).union(bookmarks))
+            if !union.isEmpty {
+                Task { @MainActor in self.beginGeohashSampling(for: union) }
+            }
         }
         // Refresh channels once when authorized to seed sampling
         LocationChannelManager.shared.$permissionState
@@ -634,6 +664,26 @@ class ChatViewModel: ObservableObject, BitchatDelegate {
                 if state == .authorized { LocationChannelManager.shared.refreshChannels() }
             }
             .store(in: &cancellables)
+
+        // Track teleport flag changes to keep our own teleported marker in sync with regional status
+        LocationChannelManager.shared.$teleported
+            .receive(on: DispatchQueue.main)
+            .sink { [weak self] isTeleported in
+                guard let self = self else { return }
+                Task { @MainActor in
+                    guard case .location(let ch) = self.activeChannel,
+                          let id = try? NostrIdentityBridge.deriveIdentity(forGeohash: ch.geohash) else { return }
+                    let key = id.publicKeyHex.lowercased()
+                    let hasRegional = !LocationChannelManager.shared.availableChannels.isEmpty
+                    let inRegional = LocationChannelManager.shared.availableChannels.contains { $0.geohash == ch.geohash }
+                    if isTeleported && hasRegional && !inRegional {
+                        self.teleportedGeo = self.teleportedGeo.union([key])
+                    } else {
+                        self.teleportedGeo.remove(key)
+                    }
+                }
+            }
+            .store(in: &cancellables)
         
         // Request notification permission
         NotificationService.shared.requestAuthorization()
@@ -746,6 +796,17 @@ class ChatViewModel: ObservableObject, BitchatDelegate {
             guard event.kind == NostrProtocol.EventKind.ephemeralEvent.rawValue else { return }
             if self.processedNostrEvents.contains(event.id) { return }
             self.processedNostrEvents.insert(event.id)
+            // PoW filter: require local difficulty for this geohash
+            let ghFromTag: String? = event.tags.first(where: { $0.first?.lowercased() == "g" && $0.count >= 2 })?.dropFirst().first
+            let ghValue = ghFromTag ?? ch.geohash
+            if let idData = Data(hexString: event.id) {
+                let powBits = NostrPoW.leadingZeroBits(idData)
+                let required = PowPolicy.requiredBits(forGeohash: ghValue)
+                if powBits < required {
+                    // Drop low PoW event
+                    return
+                }
+            }
             if let gh = self.currentGeohash,
                let myGeoIdentity = try? NostrIdentityBridge.deriveIdentity(forGeohash: gh),
                myGeoIdentity.publicKeyHex.lowercased() == event.pubkey.lowercased() {
@@ -763,8 +824,11 @@ class ChatViewModel: ObservableObject, BitchatDelegate {
             let key8 = "nostr:" + String(event.pubkey.prefix(TransportConfig.nostrShortKeyDisplayLength))
             self.nostrKeyMapping[key8] = event.pubkey
 
-            // Update participants last-seen for this pubkey
+            // Update participants last-seen for this pubkey with observed PoW bits
-            self.recordGeoParticipant(pubkeyHex: event.pubkey)
+            if let idData = Data(hexString: event.id) {
+                let powBits = NostrPoW.leadingZeroBits(idData)
+                self.recordGeoParticipant(pubkeyHex: event.pubkey, geohash: ch.geohash, powBits: powBits)
+            }
             
             // Track teleported tag (only our format ["t","teleport"]) for icon state
             let hasTeleportTag = event.tags.contains(where: { tag in
@@ -772,10 +836,19 @@ class ChatViewModel: ObservableObject, BitchatDelegate {
             })
             if hasTeleportTag {
                 let key = event.pubkey.lowercased()
-                Task { @MainActor in self.teleportedGeo = self.teleportedGeo.union([key]) }
+                // Do not mark our own key from historical events; rely on manager.teleported for self
+                let isSelf: Bool = {
+                    if let gh = self.currentGeohash, let my = try? NostrIdentityBridge.deriveIdentity(forGeohash: gh) {
+                        return my.publicKeyHex.lowercased() == key
+                    }
+                    return false
+                }()
+                if !isSelf {
+                    Task { @MainActor in self.teleportedGeo = self.teleportedGeo.union([key]) }
+                }
             }
             let senderName = self.displayNameForNostrPubkey(event.pubkey)
-            let content = event.content
+            let content = event.content.trimmingCharacters(in: .whitespacesAndNewlines)
             let timestamp = Date(timeIntervalSince1970: TimeInterval(event.created_at))
             let mentions = self.parseMentions(from: content)
             let msg = BitchatMessage(
@@ -1217,7 +1290,9 @@ class ChatViewModel: ObservableObject, BitchatDelegate {
     ///         Routes to private chat if one is selected, otherwise broadcasts
     @MainActor
     func sendMessage(_ content: String) {
-        guard !content.isEmpty else { return }
+        // Ignore messages that are empty or whitespace-only to prevent blank lines
+        let trimmed = content.trimmingCharacters(in: .whitespacesAndNewlines)
+        guard !trimmed.isEmpty else { return }
         
         // Check for commands
         if content.hasPrefix("/") {
@@ -1237,7 +1312,7 @@ class ChatViewModel: ObservableObject, BitchatDelegate {
             } else {
             }
         } else {
-            // Parse mentions from the content
+            // Parse mentions from the content (use original content for user intent)
             let mentions = parseMentions(from: content)
             
             // Add message to local display
@@ -1252,14 +1327,18 @@ class ChatViewModel: ObservableObject, BitchatDelegate {
 
             let message = BitchatMessage(
                 sender: displaySender,
-                content: content,
+                content: trimmed,
                 timestamp: Date(),
                 isRelay: false,
                 originalSender: nil,
                 isPrivate: false,
                 recipientNickname: nil,
                 senderPeerID: localSenderPeerID,
-                mentions: mentions.isEmpty ? nil : mentions
+                mentions: mentions.isEmpty ? nil : mentions,
+                deliveryStatus: nil,
+                isMiningPow: {
+                    if case .location(_) = activeChannel { return true } else { return nil }
+                }()
             )
             
             // Add to main messages immediately for user feedback
@@ -1292,17 +1371,42 @@ class ChatViewModel: ObservableObject, BitchatDelegate {
             }
             
             if case .location(let ch) = activeChannel {
-                // Send to geohash channel via Nostr ephemeral
+                // Send to geohash channel via Nostr ephemeral with PoW
-                Task { @MainActor in
+                let msgID = message.id
+                let contentToSend = trimmed
+                Task {@MainActor in
                     do {
                         let identity = try NostrIdentityBridge.deriveIdentity(forGeohash: ch.geohash)
-                        let event = try NostrProtocol.createEphemeralGeohashEvent(
+                        let createdAt = Int(message.timestamp.timeIntervalSince1970)
-                            content: content,
+                        var baseTags = [["g", ch.geohash]]
-                            geohash: ch.geohash,
+                        if !self.nickname.isEmpty { baseTags.append(["n", self.nickname]) }
-                            senderIdentity: identity,
+                        if LocationChannelManager.shared.teleported { baseTags.append(["t", "teleport"]) }
-                            nickname: self.nickname,
+                        let bits = PowPolicy.requiredBits(forGeohash: ch.geohash)
-                            teleported: LocationChannelManager.shared.teleported
+                        // Mine off the main thread
+                        let (nonce, _) = await withCheckedContinuation { (cont: CheckedContinuation<(UInt64, String), Never>) in
+                            DispatchQueue.global(qos: .utility).async {
+                                let res = NostrPoW.mine(pubkey: identity.publicKeyHex,
+                                                        createdAt: createdAt,
+                                                        kind: NostrProtocol.EventKind.ephemeralEvent.rawValue,
+                                                        baseTags: baseTags,
+                                                        content: contentToSend,
+                                                        targetBits: bits)
+                                cont.resume(returning: (res.nonce, res.idHex))
+                            }
+                        }
+                        // Build final event with nonce tag and sign
+                        var tags = baseTags
+                        tags.append(["nonce", String(nonce), String(bits)])
+                        var event = NostrEvent(
+                            pubkey: identity.publicKeyHex,
+                            createdAt: message.timestamp,
+                            kind: .ephemeralEvent,
+                            tags: tags,
+                            content: contentToSend
                         )
+                        let schnorrKey = try identity.schnorrSigningKey()
+                        event = try event.sign(with: schnorrKey)
+
                         let targetRelays = GeoRelayDirectory.shared.closestRelays(
                             toGeohash: ch.geohash,
                             count: TransportConfig.nostrGeoRelayCount
@@ -1312,12 +1416,25 @@ class ChatViewModel: ObservableObject, BitchatDelegate {
                         } else {
                             NostrRelayManager.shared.sendEvent(event, to: targetRelays)
                         }
-                        // Track ourselves as active participant
+                        // Track ourselves as active participant with PoW record
-                        self.recordGeoParticipant(pubkeyHex: identity.publicKeyHex)
+                        if let idData = Data(hexString: event.id) {
-                        SecureLogger.log("GeoTeleport: sent geo message pub=\(identity.publicKeyHex.prefix(8))… teleported=\(LocationChannelManager.shared.teleported)",
+                            let powBits = NostrPoW.leadingZeroBits(idData)
-                                        category: SecureLogger.session, level: .debug)
+                            self.recordGeoParticipant(pubkeyHex: identity.publicKeyHex, geohash: ch.geohash, powBits: powBits)
-                        // If we tagged this as teleported, also mark our pubkey in teleportedGeo for UI
+                        } else {
-                        if LocationChannelManager.shared.teleported {
+                            self.recordGeoParticipant(pubkeyHex: identity.publicKeyHex)
+                        }
+                        SecureLogger.log("Geo: sent geo event id=\(event.id.prefix(12))… bits=\(bits) nonce=\(String(nonce))", category: SecureLogger.session, level: .debug)
+                        // Reveal timestamp / stop animation
+                        if let idx = self.messages.firstIndex(where: { $0.id == msgID }) {
+                            self.messages[idx].isMiningPow = false
+                            self.messages[idx].clearCachedFormattedText()
+                            // Trigger UI refresh so timestamp appears
+                            self.objectWillChange.send()
+                        }
+                        // If teleported and outside regional set, mark self teleported
+                        let hasRegional = !LocationChannelManager.shared.availableChannels.isEmpty
+                        let inRegional = LocationChannelManager.shared.availableChannels.contains { $0.geohash == ch.geohash }
+                        if LocationChannelManager.shared.teleported && hasRegional && !inRegional {
                             let key = identity.publicKeyHex.lowercased()
                             self.teleportedGeo = self.teleportedGeo.union([key])
                             SecureLogger.log("GeoTeleport: mark self teleported key=\(key.prefix(8))… total=\(self.teleportedGeo.count)",
@@ -1326,6 +1443,11 @@ class ChatViewModel: ObservableObject, BitchatDelegate {
                     } catch {
                         SecureLogger.log("❌ Failed to send geohash message: \(error)", category: SecureLogger.session, level: .error)
                         self.addSystemMessage("failed to send to location channel")
+                        if let idx = self.messages.firstIndex(where: { $0.id == msgID }) {
+                            self.messages[idx].isMiningPow = false
+                            self.messages[idx].clearCachedFormattedText()
+                            self.objectWillChange.send()
+                        }
                     }
                 }
             } else {
@@ -1348,16 +1470,38 @@ class ChatViewModel: ObservableObject, BitchatDelegate {
         switch channel {
         case .mesh:
             messages = meshTimeline
+            // Debug: log if any empty messages are present
+            let emptyMesh = messages.filter { $0.content.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty }.count
+            if emptyMesh > 0 {
+                SecureLogger.log("RenderGuard: mesh timeline contains \(emptyMesh) empty messages", category: SecureLogger.session, level: .debug)
+            }
             stopGeoParticipantsTimer()
             geohashPeople = []
             teleportedGeo.removeAll()
         case .location(let ch):
             // Sanitize existing timeline (filter any prior empty-content entries)
             var arr = geoTimelines[ch.geohash] ?? []
-            let before = arr.count
             arr.removeAll { $0.content.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty }
-            if arr.count != before { geoTimelines[ch.geohash] = arr }
+            // Deduplicate by ID while preserving order (from oldest to newest)
+            if arr.count > 1 {
+                var seen = Set<String>()
+                var dedup: [BitchatMessage] = []
+                for m in arr.sorted(by: { $0.timestamp < $1.timestamp }) {
+                    if !seen.contains(m.id) {
+                        dedup.append(m)
+                        seen.insert(m.id)
+                    }
+                }
+                arr = dedup
+            }
+            // Persist the cleaned/sorted timeline for this geohash
+            geoTimelines[ch.geohash] = arr
             messages = arr
+            // Debug: log if any empty messages are present post-sanitize
+            let emptyGeo = messages.filter { $0.content.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty }.count
+            if emptyGeo > 0 {
+                SecureLogger.log("RenderGuard: geohash \(ch.geohash) timeline has \(emptyGeo) empty messages after sanitize", category: SecureLogger.session, level: .debug)
+            }
         }
         // Unsubscribe previous
         if let sub = geoSubscriptionID {
@@ -1375,14 +1519,18 @@ class ChatViewModel: ObservableObject, BitchatDelegate {
         
         guard case .location(let ch) = channel else { return }
         currentGeohash = ch.geohash
-        // Ensure self appears immediately in the people list; mark teleported state if applicable
+        // Ensure self appears immediately in the people list; mark teleported state only when truly teleported
         if let id = try? NostrIdentityBridge.deriveIdentity(forGeohash: ch.geohash) {
             self.recordGeoParticipant(pubkeyHex: id.publicKeyHex)
-            if LocationChannelManager.shared.teleported {
+            let hasRegional = !LocationChannelManager.shared.availableChannels.isEmpty
-                let key = id.publicKeyHex.lowercased()
+            let inRegional = LocationChannelManager.shared.availableChannels.contains { $0.geohash == ch.geohash }
+            let key = id.publicKeyHex.lowercased()
+            if LocationChannelManager.shared.teleported && hasRegional && !inRegional {
                 teleportedGeo = teleportedGeo.union([key])
                 SecureLogger.log("GeoTeleport: channel switch mark self teleported key=\(key.prefix(8))… total=\(teleportedGeo.count)",
                                 category: SecureLogger.session, level: .info)
+            } else {
+                teleportedGeo.remove(key)
             }
         }
         let subID = "geo-\(ch.geohash)"
@@ -1401,6 +1549,16 @@ class ChatViewModel: ObservableObject, BitchatDelegate {
             // Deduplicate
             if self.processedNostrEvents.contains(event.id) { return }
             self.recordProcessedEvent(event.id)
+            // PoW filter for geohash events
+            let ghFromTag: String? = event.tags.first(where: { $0.first?.lowercased() == "g" && $0.count >= 2 })?.dropFirst().first
+            let ghValue = ghFromTag ?? ch.geohash
+            if let idData = Data(hexString: event.id) {
+                let powBits = NostrPoW.leadingZeroBits(idData)
+                let required = PowPolicy.requiredBits(forGeohash: ghValue)
+                if powBits < required {
+                    return
+                }
+            }
             // Log incoming tags for diagnostics
             let tagSummary = event.tags.map { "[" + $0.joined(separator: ",") + "]" }.joined(separator: ",")
             SecureLogger.log("GeoTeleport: recv pub=\(event.pubkey.prefix(8))… tags=\(tagSummary)",
@@ -1411,10 +1569,19 @@ class ChatViewModel: ObservableObject, BitchatDelegate {
             })
             if hasTeleportTag {
                 let key = event.pubkey.lowercased()
-                Task { @MainActor in
+                // Avoid marking our own key from historical events; rely on manager.teleported for self
-                    self.teleportedGeo = self.teleportedGeo.union([key])
+                let isSelf: Bool = {
-                    SecureLogger.log("GeoTeleport: mark peer teleported key=\(key.prefix(8))… total=\(self.teleportedGeo.count)",
+                    if let gh = self.currentGeohash, let my = try? NostrIdentityBridge.deriveIdentity(forGeohash: gh) {
-                                    category: SecureLogger.session, level: .info)
+                        return my.publicKeyHex.lowercased() == key
+                    }
+                    return false
+                }()
+                if !isSelf {
+                    Task { @MainActor in
+                        self.teleportedGeo = self.teleportedGeo.union([key])
+                        SecureLogger.log("GeoTeleport: mark peer teleported key=\(key.prefix(8))… total=\(self.teleportedGeo.count)",
+                                        category: SecureLogger.session, level: .info)
+                    }
                 }
             }
             // Skip only very recent self-echo from relay; include older self events for hydration
@@ -1438,8 +1605,11 @@ class ChatViewModel: ObservableObject, BitchatDelegate {
             self.nostrKeyMapping[key16] = event.pubkey
             let key8 = "nostr:" + String(event.pubkey.prefix(TransportConfig.nostrShortKeyDisplayLength))
             self.nostrKeyMapping[key8] = event.pubkey
-            // Update participants last-seen for this pubkey
+            // Update participants last-seen for this pubkey with observed PoW bits
-            self.recordGeoParticipant(pubkeyHex: event.pubkey)
+            if let idData = Data(hexString: event.id) {
+                let powBits = NostrPoW.leadingZeroBits(idData)
+                self.recordGeoParticipant(pubkeyHex: event.pubkey, geohash: ch.geohash, powBits: powBits)
+            }
             
             let senderName = self.displayNameForNostrPubkey(event.pubkey)
             let content = event.content
@@ -1624,6 +1794,24 @@ class ChatViewModel: ObservableObject, BitchatDelegate {
         }
     }
 
+    // Track last observed PoW bits per participant per geohash
+    private var geoParticipantPowBits: [String: [String: Int]] = [:] // geohash -> (pubkeyLower -> bits)
+
+    private func recordGeoParticipant(pubkeyHex: String, geohash: String, powBits: Int?) {
+        let key = pubkeyHex.lowercased()
+        var map = geoParticipants[geohash] ?? [:]
+        map[key] = Date()
+        geoParticipants[geohash] = map
+        if let bits = powBits {
+            var powMap = geoParticipantPowBits[geohash] ?? [:]
+            powMap[key] = bits
+            geoParticipantPowBits[geohash] = powMap
+        }
+        if currentGeohash == geohash {
+            refreshGeohashPeople()
+        }
+    }
+
     private func refreshGeohashPeople() {
         guard let gh = currentGeohash else { geohashPeople = []; return }
         let cutoff = Date().addingTimeInterval(-TransportConfig.uiRecentCutoffFiveMinutesSeconds)
@@ -1632,6 +1820,17 @@ class ChatViewModel: ObservableObject, BitchatDelegate {
         map = map.filter { $0.value >= cutoff }
         // Remove blocked Nostr pubkeys
         map = map.filter { !SecureIdentityStateManager.shared.isNostrBlocked(pubkeyHexLowercased: $0.key) }
+        // Enforce PoW threshold for peer list as well
+        let required = PowPolicy.requiredBits(forGeohash: gh)
+        let myHex: String? = (try? NostrIdentityBridge.deriveIdentity(forGeohash: gh))?.publicKeyHex.lowercased()
+        let powMap = geoParticipantPowBits[gh] ?? [:]
+        map = map.filter { (pub, _) in
+            if let bits = powMap[pub] { return bits >= required }
+            // Always allow self even if no PoW record yet
+            if let me = myHex, pub == me { return true }
+            // Otherwise, if no PoW info, hide until we see an acceptable event
+            return false
+        }
         geoParticipants[gh] = map
         // Build display list
         let people = map
@@ -1662,9 +1861,17 @@ class ChatViewModel: ObservableObject, BitchatDelegate {
     func visibleGeohashPeople() -> [GeoPerson] {
         guard let gh = currentGeohash else { return [] }
         let cutoff = Date().addingTimeInterval(-TransportConfig.uiRecentCutoffFiveMinutesSeconds)
+        let required = PowPolicy.requiredBits(forGeohash: gh)
+        let myHex: String? = (try? NostrIdentityBridge.deriveIdentity(forGeohash: gh))?.publicKeyHex.lowercased()
+        let powMap = geoParticipantPowBits[gh] ?? [:]
         let map = (geoParticipants[gh] ?? [:])
             .filter { $0.value >= cutoff }
             .filter { !SecureIdentityStateManager.shared.isNostrBlocked(pubkeyHexLowercased: $0.key) }
+            .filter { (pub, _) in
+                if let bits = powMap[pub] { return bits >= required }
+                if let me = myHex, pub == me { return true }
+                return false
+            }
         let people = map
             .map { (pub, seen) in GeoPerson(id: pub, displayName: displayNameForNostrPubkey(pub), lastSeen: seen) }
             .sorted { $0.lastSeen > $1.lastSeen }
@@ -1766,17 +1973,38 @@ class ChatViewModel: ObservableObject, BitchatDelegate {
             NostrRelayManager.shared.subscribe(filter: filter, id: subID, relayUrls: subRelays) { [weak self] event in
                 guard let self = self else { return }
                 guard event.kind == NostrProtocol.EventKind.ephemeralEvent.rawValue else { return }
+                // Enforce PoW for sampled geohashes too
+                if let idData = Data(hexString: event.id) {
+                    let powBits = NostrPoW.leadingZeroBits(idData)
+                    let required = PowPolicy.requiredBits(forGeohash: gh)
+                    if powBits < required { return }
+                }
+                // Compute current participant count (5-minute window) BEFORE updating with this event
+                let cutoff = Date().addingTimeInterval(-TransportConfig.uiRecentCutoffFiveMinutesSeconds)
+                let existingCount: Int = {
+                    let map = self.geoParticipants[gh] ?? [:]
+                    return map.values.filter { $0 >= cutoff }.count
+                }()
                 // Update participants for this specific geohash
-                self.recordGeoParticipant(pubkeyHex: event.pubkey, geohash: gh)
+                if let idData = Data(hexString: event.id) {
-                // Notify on new message activity in this geohash (sampling across channels)
+                    let powBits = NostrPoW.leadingZeroBits(idData)
+                    self.recordGeoParticipant(pubkeyHex: event.pubkey, geohash: gh, powBits: powBits)
+                } else {
+                    self.recordGeoParticipant(pubkeyHex: event.pubkey, geohash: gh)
+                }
+                // Notify only on rising-edge: previously zero people, now someone sends a chat
                 let content = event.content.trimmingCharacters(in: .whitespacesAndNewlines)
                 guard !content.isEmpty else { return }
                 // Respect geohash blocks
                 if SecureIdentityStateManager.shared.isNostrBlocked(pubkeyHexLowercased: event.pubkey.lowercased()) { return }
                 // Skip self identity for this geohash
                 if let my = try? NostrIdentityBridge.deriveIdentity(forGeohash: gh), my.publicKeyHex.lowercased() == event.pubkey.lowercased() { return }
+                // Only trigger when there were zero participants in this geohash recently
+                guard existingCount == 0 else { return }
+                // Avoid notifications for old sampled events when launching or (re)subscribing
+                let eventTime = Date(timeIntervalSince1970: TimeInterval(event.created_at))
+                if Date().timeIntervalSince(eventTime) > 30 { return }
                 // Foreground policy: allow if it's a different geohash than the one currently open
-                // Suppress only when app is active AND we're already in this same geohash channel
                 #if os(iOS)
                 if UIApplication.shared.applicationState == .active {
                     if case .location(let ch) = self.activeChannel, ch.geohash == gh { return }
@@ -1799,6 +2027,30 @@ class ChatViewModel: ObservableObject, BitchatDelegate {
                 }()
                 Task { @MainActor in
                     self.lastGeoNotificationAt[gh] = now
+                    // Pre-populate the target geohash timeline so the triggering message appears when user opens it
+                    var arr = self.geoTimelines[gh] ?? []
+                    let senderSuffix = String(event.pubkey.suffix(4))
+                    let nick = self.geoNicknames[event.pubkey.lowercased()]
+                    let senderName = (nick?.isEmpty == false ? nick! : "anon") + "#" + senderSuffix
+                    let ts = Date(timeIntervalSince1970: TimeInterval(event.created_at))
+                    let mentions = self.parseMentions(from: content)
+                    let msg = BitchatMessage(
+                        id: event.id,
+                        sender: senderName,
+                        content: content,
+                        timestamp: ts,
+                        isRelay: false,
+                        originalSender: nil,
+                        isPrivate: false,
+                        recipientNickname: nil,
+                        senderPeerID: "nostr:\(event.pubkey.prefix(TransportConfig.nostrShortKeyDisplayLength))",
+                        mentions: mentions.isEmpty ? nil : mentions
+                    )
+                    if !arr.contains(where: { $0.id == msg.id }) {
+                        arr.append(msg)
+                        if arr.count > self.geoTimelineCap { arr = Array(arr.suffix(self.geoTimelineCap)) }
+                        self.geoTimelines[gh] = arr
+                    }
                     NotificationService.shared.sendGeohashActivityNotification(geohash: gh, bodyPreview: preview)
                 }
             }
@@ -2478,6 +2730,17 @@ class ChatViewModel: ObservableObject, BitchatDelegate {
     
     @MainActor
     @objc private func userDidTakeScreenshot() {
+        // Respect privacy: do not broadcast screenshots taken from non-chat sheets
+        if isLocationChannelsSheetPresented {
+            // Show a warning about sharing location screenshots publicly
+            showScreenshotPrivacyWarning = true
+            return
+        }
+        if isAppInfoPresented {
+            // Silently ignore screenshots of app info
+            return
+        }
+
         // Send screenshot notification based on current context
         let screenshotMessage = "* \(nickname) took a screenshot *"
         
@@ -2497,7 +2760,7 @@ class ChatViewModel: ObservableObject, BitchatDelegate {
                 }
             }
             
-            // Show local notification immediately as system message
+            // Show local notification immediately as system message (only in chat)
             let localNotification = BitchatMessage(
                 sender: "system",
                 content: "you took a screenshot",
@@ -2523,32 +2786,12 @@ class ChatViewModel: ObservableObject, BitchatDelegate {
                 meshService.sendMessage(screenshotMessage, mentions: [])
             case .location(let ch):
                 Task { @MainActor in
-                    do {
+                    await mineAndSendGeohashEvent(content: screenshotMessage, geohash: ch.geohash, nickname: self.nickname, teleported: LocationChannelManager.shared.teleported, createdAt: Date())
-                        let identity = try NostrIdentityBridge.deriveIdentity(forGeohash: ch.geohash)
-                        let event = try NostrProtocol.createEphemeralGeohashEvent(
-                            content: screenshotMessage,
-                            geohash: ch.geohash,
-                            senderIdentity: identity,
-                            nickname: self.nickname,
-                            teleported: LocationChannelManager.shared.teleported
-                        )
-                        let targetRelays = GeoRelayDirectory.shared.closestRelays(toGeohash: ch.geohash, count: 5)
-                        if targetRelays.isEmpty {
-                            SecureLogger.log("Geo: no geohash relays available for \(ch.geohash); not sending", category: SecureLogger.session, level: .warning)
-                        } else {
-                            NostrRelayManager.shared.sendEvent(event, to: targetRelays)
-                        }
-                        // Track ourselves as active participant
-                        self.recordGeoParticipant(pubkeyHex: identity.publicKeyHex)
-                    } catch {
-                        SecureLogger.log("❌ Failed to send geohash screenshot message: \(error)", category: SecureLogger.session, level: .error)
-                        self.addSystemMessage("failed to send to location channel")
-                    }
                 }
             }
             
 
-            // Show local notification immediately as system message
+            // Show local notification immediately as system message (only in chat)
             let localNotification = BitchatMessage(
                 sender: "system",
                 content: "you took a screenshot",
@@ -2933,8 +3176,10 @@ class ChatViewModel: ObservableObject, BitchatDelegate {
         let mentionRegex = try? NSRegularExpression(pattern: mentionPattern, options: [])
         let hashtagRegex = try? NSRegularExpression(pattern: hashtagPattern, options: [])
         
-        let mentionMatches = mentionRegex?.matches(in: contentText, options: [], range: NSRange(location: 0, length: contentText.count)) ?? []
+        let nsContent = contentText as NSString
-        let hashtagMatches = hashtagRegex?.matches(in: contentText, options: [], range: NSRange(location: 0, length: contentText.count)) ?? []
+        let nsLen = nsContent.length
+        let mentionMatches = mentionRegex?.matches(in: contentText, options: [], range: NSRange(location: 0, length: nsLen)) ?? []
+        let hashtagMatches = hashtagRegex?.matches(in: contentText, options: [], range: NSRange(location: 0, length: nsLen)) ?? []
         
         // Combine and sort all matches
         var allMatches: [(range: NSRange, type: String)] = []
@@ -2951,12 +3196,14 @@ class ChatViewModel: ObservableObject, BitchatDelegate {
         for (matchRange, matchType) in allMatches {
             // Add text before the match
             if let range = Range(matchRange, in: contentText) {
-                let beforeText = String(contentText[lastEndIndex..<range.lowerBound])
+                if lastEndIndex < range.lowerBound {
-                if !beforeText.isEmpty {
+                    let beforeText = String(contentText[lastEndIndex..<range.lowerBound])
-                    var normalStyle = AttributeContainer()
+                    if !beforeText.isEmpty {
-                    normalStyle.font = .system(size: 14, design: .monospaced)
+                        var normalStyle = AttributeContainer()
-                    normalStyle.foregroundColor = isDark ? Color.white : Color.black
+                        normalStyle.font = .system(size: 14, design: .monospaced)
-                    processedContent.append(AttributedString(beforeText).mergingAttributes(normalStyle))
+                        normalStyle.foregroundColor = isDark ? Color.white : Color.black
+                        processedContent.append(AttributedString(beforeText).mergingAttributes(normalStyle))
+                    }
                 }
                 
                 // Add the match with appropriate styling
@@ -2974,7 +3221,7 @@ class ChatViewModel: ObservableObject, BitchatDelegate {
                 
                 processedContent.append(AttributedString(matchText).mergingAttributes(matchStyle))
                 
-                lastEndIndex = range.upperBound
+                if lastEndIndex < range.upperBound { lastEndIndex = range.upperBound }
             }
         }
         
@@ -2989,6 +3236,59 @@ class ChatViewModel: ObservableObject, BitchatDelegate {
         
         return processedContent
     }
+
+    // MARK: - Helpers for mining UI
+    @MainActor
+    func isSelfMessage(_ message: BitchatMessage) -> Bool {
+        let isSelf: Bool = {
+            if let spid = message.senderPeerID {
+                if spid == meshService.myPeerID { return true }
+                if case .location(let ch) = activeChannel,
+                   let id = try? NostrIdentityBridge.deriveIdentity(forGeohash: ch.geohash) {
+                    if spid.hasPrefix("nostr:") || spid.hasPrefix("nostr_") {
+                        let bare: String = spid.hasPrefix("nostr:") ? String(spid.dropFirst(6)) : String(spid.dropFirst(6))
+                        return bare.lowercased().hasPrefix(id.publicKeyHex.lowercased().prefix(TransportConfig.nostrShortKeyDisplayLength))
+                    }
+                }
+                return spid == meshService.myPeerID
+            }
+            if message.sender == nickname { return true }
+            if message.sender.hasPrefix(nickname + "#") { return true }
+            return false
+        }()
+        return isSelf
+    }
+
+    @MainActor
+    func baseColorForMessage(_ message: BitchatMessage, colorScheme: ColorScheme) -> Color {
+        let isDark = colorScheme == .dark
+        return isSelfMessage(message) ? .orange : peerColor(for: message, isDark: isDark)
+    }
+
+    @MainActor
+    func formatSenderPrefix(_ message: BitchatMessage, colorScheme: ColorScheme) -> AttributedString {
+        let isSelf = isSelfMessage(message)
+        let isDark = colorScheme == .dark
+        let baseColor: Color = isSelf ? .orange : peerColor(for: message, isDark: isDark)
+        let (baseName, suffix) = splitSuffix(from: message.sender)
+        var senderStyle = AttributeContainer()
+        senderStyle.foregroundColor = baseColor
+        let fontWeight: Font.Weight = isSelf ? .bold : .medium
+        senderStyle.font = .system(size: 14, weight: fontWeight, design: .monospaced)
+        if let spid = message.senderPeerID, let url = URL(string: "bitchat://user/\(spid.addingPercentEncoding(withAllowedCharacters: .urlPathAllowed) ?? spid)") {
+            senderStyle.link = url
+        }
+        var prefix = AttributedString()
+        prefix.append(AttributedString("<@").mergingAttributes(senderStyle))
+        prefix.append(AttributedString(baseName).mergingAttributes(senderStyle))
+        if !suffix.isEmpty {
+            var suffixStyle = senderStyle
+            suffixStyle.foregroundColor = baseColor.opacity(0.6)
+            prefix.append(AttributedString(suffix).mergingAttributes(suffixStyle))
+        }
+        prefix.append(AttributedString("> ").mergingAttributes(senderStyle))
+        return prefix
+    }
     
     @MainActor
     func formatMessageAsText(_ message: BitchatMessage, colorScheme: ColorScheme) -> AttributedString {
@@ -3051,9 +3351,12 @@ class ChatViewModel: ObservableObject, BitchatDelegate {
             
             // For extremely long content, render as plain text to avoid heavy regex/layout work,
             // unless the content includes Cashu tokens we want to chip-render below
+            // Compute NSString-backed length for regex/nsrange correctness with multi-byte characters
+            let nsContent = content as NSString
+            let nsLen = nsContent.length
             let containsCashuEarly: Bool = {
                 let rx = Regexes.quickCashuPresence
-                return rx.numberOfMatches(in: content, options: [], range: NSRange(location: 0, length: content.count)) > 0
+                return rx.numberOfMatches(in: content, options: [], range: NSRange(location: 0, length: nsLen)) > 0
             }()
             if (content.count > 4000 || content.hasVeryLongToken(threshold: 1024)) && !containsCashuEarly {
                 var plainStyle = AttributeContainer()
@@ -3071,8 +3374,6 @@ class ChatViewModel: ObservableObject, BitchatDelegate {
             let lnurlRegex = Regexes.lnurl
             let lightningSchemeRegex = Regexes.lightningScheme
             let detector = Regexes.linkDetector
-            
-            let nsLen = content.count
             let hasMentionsHint = content.contains("@")
             let hasHashtagsHint = content.contains("#")
             let hasURLHint = content.contains("://") || content.contains("www.") || content.contains("http")
@@ -3152,17 +3453,19 @@ class ChatViewModel: ObservableObject, BitchatDelegate {
             for (range, type) in allMatches {
                 // Add text before match
                 if let nsRange = Range(range, in: content) {
-                    let beforeText = String(content[lastEnd..<nsRange.lowerBound])
+                    if lastEnd < nsRange.lowerBound {
-                    if !beforeText.isEmpty {
+                        let beforeText = String(content[lastEnd..<nsRange.lowerBound])
-                        var beforeStyle = AttributeContainer()
+                        if !beforeText.isEmpty {
-                        beforeStyle.foregroundColor = baseColor
+                            var beforeStyle = AttributeContainer()
-                        beforeStyle.font = isSelf
+                            beforeStyle.foregroundColor = baseColor
-                            ? .system(size: 14, weight: .bold, design: .monospaced)
+                            beforeStyle.font = isSelf
-                            : .system(size: 14, design: .monospaced)
+                                ? .system(size: 14, weight: .bold, design: .monospaced)
-                        if isMentioned {
+                                : .system(size: 14, design: .monospaced)
-                            beforeStyle.font = beforeStyle.font?.bold()
+                            if isMentioned {
+                                beforeStyle.font = beforeStyle.font?.bold()
+                            }
+                            result.append(AttributedString(beforeText).mergingAttributes(beforeStyle))
                         }
-                        result.append(AttributedString(beforeText).mergingAttributes(beforeStyle))
                     }
                     
                     // Add styled match
@@ -3270,7 +3573,10 @@ class ChatViewModel: ObservableObject, BitchatDelegate {
                             result.append(AttributedString(matchText).mergingAttributes(matchStyle))
                         }
                     }
-                    lastEnd = nsRange.upperBound
+                    // Advance lastEnd safely in case of overlaps
+                    if lastEnd < nsRange.upperBound {
+                        lastEnd = nsRange.upperBound
+                    }
                 }
             }
             
@@ -3289,12 +3595,15 @@ class ChatViewModel: ObservableObject, BitchatDelegate {
             }
             }
             
-            // Add timestamp at the end (smaller, light grey)
+            // Add timestamp at the end (hide while PoW mining)
-            let timestamp = AttributedString(" [\(formatTimestamp(message.timestamp))]")
+            let hideTimestamp = (message.isMiningPow ?? false)
-            var timestampStyle = AttributeContainer()
+            if !hideTimestamp {
-            timestampStyle.foregroundColor = Color.gray.opacity(0.7)
+                let timestamp = AttributedString(" [\(formatTimestamp(message.timestamp))]")
-            timestampStyle.font = .system(size: 10, design: .monospaced)
+                var timestampStyle = AttributeContainer()
-            result.append(timestamp.mergingAttributes(timestampStyle))
+                timestampStyle.foregroundColor = Color.gray.opacity(0.7)
+                timestampStyle.font = .system(size: 10, design: .monospaced)
+                result.append(timestamp.mergingAttributes(timestampStyle))
+            }
         } else {
             // System message
             var contentStyle = AttributeContainer()
@@ -3368,19 +3677,23 @@ class ChatViewModel: ObservableObject, BitchatDelegate {
             // Regular expression to find @mentions
             let pattern = "@([\\p{L}0-9_]+)"
             let regex = try? NSRegularExpression(pattern: pattern, options: [])
-            let matches = regex?.matches(in: contentText, options: [], range: NSRange(location: 0, length: contentText.count)) ?? []
+            let nsContent = contentText as NSString
+            let nsLen = nsContent.length
+            let matches = regex?.matches(in: contentText, options: [], range: NSRange(location: 0, length: nsLen)) ?? []
             
             var lastEndIndex = contentText.startIndex
             
             for match in matches {
                 // Add text before the mention
                 if let range = Range(match.range(at: 0), in: contentText) {
-                    let beforeText = String(contentText[lastEndIndex..<range.lowerBound])
+                    if lastEndIndex < range.lowerBound {
-                    if !beforeText.isEmpty {
+                        let beforeText = String(contentText[lastEndIndex..<range.lowerBound])
-                        var normalStyle = AttributeContainer()
+                        if !beforeText.isEmpty {
-                        normalStyle.font = .system(size: 14, design: .monospaced)
+                            var normalStyle = AttributeContainer()
-                        normalStyle.foregroundColor = isDark ? Color.white : Color.black
+                            normalStyle.font = .system(size: 14, design: .monospaced)
-                        processedContent.append(AttributedString(beforeText).mergingAttributes(normalStyle))
+                            normalStyle.foregroundColor = isDark ? Color.white : Color.black
+                            processedContent.append(AttributedString(beforeText).mergingAttributes(normalStyle))
+                        }
                     }
                     
                     // Add the mention with highlight
@@ -3390,7 +3703,7 @@ class ChatViewModel: ObservableObject, BitchatDelegate {
                     mentionStyle.foregroundColor = Color.orange
                     processedContent.append(AttributedString(mentionText).mergingAttributes(mentionStyle))
                     
-                    lastEndIndex = range.upperBound
+                    if lastEndIndex < range.upperBound { lastEndIndex = range.upperBound }
                 }
             }
             
@@ -4288,11 +4601,12 @@ class ChatViewModel: ObservableObject, BitchatDelegate {
 
     func didReceivePublicMessage(from peerID: String, nickname: String, content: String, timestamp: Date) {
         Task { @MainActor in
-            let publicMentions = parseMentions(from: content)
+            let normalized = content.trimmingCharacters(in: .whitespacesAndNewlines)
+            let publicMentions = parseMentions(from: normalized)
             let msg = BitchatMessage(
                 id: UUID().uuidString,
                 sender: nickname,
-                content: content,
+                content: normalized,
                 timestamp: timestamp,
                 isRelay: false,
                 originalSender: nil,
@@ -4466,14 +4780,10 @@ class ChatViewModel: ObservableObject, BitchatDelegate {
                     self.meshService.isPeerConnected(peerID) || self.meshService.isPeerReachable(peerID)
                 }
                 
-                // Check if we have new mesh peers we haven't seen recently
+                // Rising-edge only: previously zero peers, now > 0 peers
                 let currentPeerSet = Set(meshPeers)
-                let newPeers = currentPeerSet.subtracting(self.recentlySeenPeers)
+                let hadNone = self.recentlySeenPeers.isEmpty
-                // Send notification if:
+                if meshPeers.count > 0 && hadNone && !self.hasNotifiedNetworkAvailable {
-                // 1. We have mesh peers (not just Nostr-only)
-                // 2. There are new peers we haven't seen (rising-edge)
-                // 3. We haven't already notified since the last sustained-empty period
-                if meshPeers.count > 0 && !newPeers.isEmpty && !self.hasNotifiedNetworkAvailable {
                     self.hasNotifiedNetworkAvailable = true
                     self.lastNetworkNotificationTime = Date()
                     self.recentlySeenPeers = currentPeerSet
@@ -4482,16 +4792,14 @@ class ChatViewModel: ObservableObject, BitchatDelegate {
                                    category: SecureLogger.session, level: .info)
                 }
             } else {
-                // No peers - schedule a graceful reset to avoid refiring on brief drops
+                // No peers — immediately reset to allow next rising-edge to notify
-                if self.networkResetTimer == nil {
+                self.hasNotifiedNetworkAvailable = false
-                    self.networkResetTimer = Timer.scheduledTimer(withTimeInterval: self.networkResetGraceSeconds, repeats: false) { [weak self] _ in
+                self.recentlySeenPeers.removeAll()
-                        guard let self = self else { return }
+                if self.networkResetTimer != nil {
-                        self.hasNotifiedNetworkAvailable = false
+                    self.networkResetTimer?.invalidate()
-                        self.recentlySeenPeers.removeAll()
+                    self.networkResetTimer = nil
-                        self.networkResetTimer = nil
-                        SecureLogger.log("⏳ Mesh empty for \(Int(self.networkResetGraceSeconds))s — reset network notification state", category: SecureLogger.session, level: .debug)
-                    }
                 }
+                SecureLogger.log("⏳ Mesh empty — reset network notification state", category: SecureLogger.session, level: .debug)
             }
             
             // Register ephemeral sessions for all connected peers
@@ -4593,7 +4901,9 @@ class ChatViewModel: ObservableObject, BitchatDelegate {
         // Allow optional disambiguation suffix '#abcd' for duplicate nicknames
         let pattern = "@([\\p{L}0-9_]+(?:#[a-fA-F0-9]{4})?)"
         let regex = try? NSRegularExpression(pattern: pattern, options: [])
-        let matches = regex?.matches(in: content, options: [], range: NSRange(location: 0, length: content.count)) ?? []
+        let nsContent = content as NSString
+        let nsLen = nsContent.length
+        let matches = regex?.matches(in: content, options: [], range: NSRange(location: 0, length: nsLen)) ?? []
         
         var mentions: [String] = []
         let peerNicknames = meshService.getPeerNicknames()
@@ -4728,30 +5038,56 @@ class ChatViewModel: ObservableObject, BitchatDelegate {
     func sendPublicRaw(_ content: String) {
         if case .location(let ch) = activeChannel {
             Task { @MainActor in
-                do {
+                await mineAndSendGeohashEvent(content: content, geohash: ch.geohash, nickname: self.nickname, teleported: LocationChannelManager.shared.teleported, createdAt: Date())
-                    let identity = try NostrIdentityBridge.deriveIdentity(forGeohash: ch.geohash)
-                    let event = try NostrProtocol.createEphemeralGeohashEvent(
-                        content: content,
-                        geohash: ch.geohash,
-                        senderIdentity: identity,
-                        nickname: self.nickname,
-                        teleported: LocationChannelManager.shared.teleported
-                    )
-                    let targetRelays = GeoRelayDirectory.shared.closestRelays(toGeohash: ch.geohash, count: 5)
-                    if targetRelays.isEmpty {
-                        NostrRelayManager.shared.sendEvent(event)
-                    } else {
-                        NostrRelayManager.shared.sendEvent(event, to: targetRelays)
-                    }
-                } catch {
-                    SecureLogger.log("❌ Failed to send geohash raw message: \(error)", category: SecureLogger.session, level: .error)
-                }
             }
             return
         }
         // Default: send over mesh
         meshService.sendMessage(content, mentions: [])
     }
+
+    // MARK: - Geohash PoW helper for system/raw messages
+    @MainActor
+    private func mineAndSendGeohashEvent(content: String, geohash: String, nickname: String, teleported: Bool, createdAt: Date) async {
+        do {
+            let identity = try NostrIdentityBridge.deriveIdentity(forGeohash: geohash)
+            let createdAtSecs = Int(createdAt.timeIntervalSince1970)
+            var baseTags = [["g", geohash]]
+            if !nickname.isEmpty { baseTags.append(["n", nickname]) }
+            if teleported { baseTags.append(["t", "teleport"]) }
+            let bits = PowPolicy.requiredBits(forGeohash: geohash)
+            let (nonce, _) = await withCheckedContinuation { (cont: CheckedContinuation<(UInt64, String), Never>) in
+                DispatchQueue.global(qos: .utility).async {
+                    let res = NostrPoW.mine(pubkey: identity.publicKeyHex,
+                                            createdAt: createdAtSecs,
+                                            kind: NostrProtocol.EventKind.ephemeralEvent.rawValue,
+                                            baseTags: baseTags,
+                                            content: content,
+                                            targetBits: bits)
+                    cont.resume(returning: (res.nonce, res.idHex))
+                }
+            }
+            var tags = baseTags
+            tags.append(["nonce", String(nonce), String(bits)])
+            var event = NostrEvent(
+                pubkey: identity.publicKeyHex,
+                createdAt: createdAt,
+                kind: .ephemeralEvent,
+                tags: tags,
+                content: content
+            )
+            let key = try identity.schnorrSigningKey()
+            event = try event.sign(with: key)
+            let relays = GeoRelayDirectory.shared.closestRelays(toGeohash: geohash, count: TransportConfig.nostrGeoRelayCount)
+            if relays.isEmpty {
+                NostrRelayManager.shared.sendEvent(event)
+            } else {
+                NostrRelayManager.shared.sendEvent(event, to: relays)
+            }
+        } catch {
+            SecureLogger.log("❌ GeoPoW: failed to send event: \(error)", category: SecureLogger.session, level: .error)
+        }
+    }
     
     // MARK: - Simplified Nostr Integration (Inlined from MessageRouter)
     
@@ -5660,9 +5996,12 @@ class ChatViewModel: ObservableObject, BitchatDelegate {
         if isGeo && finalMessage.sender != "system" {
             if let gh = currentGeohash {
                 var arr = geoTimelines[gh] ?? []
-                arr.append(finalMessage)
+                // Dedup by message ID before appending to per-geohash timeline
-                if arr.count > geoTimelineCap { arr = Array(arr.suffix(geoTimelineCap)) }
+                if !arr.contains(where: { $0.id == finalMessage.id }) {
-                geoTimelines[gh] = arr
+                    arr.append(finalMessage)
+                    if arr.count > geoTimelineCap { arr = Array(arr.suffix(geoTimelineCap)) }
+                    geoTimelines[gh] = arr
+                }
             }
         }
 
@@ -5677,38 +6016,13 @@ class ChatViewModel: ObservableObject, BitchatDelegate {
 
         guard channelMatches else { return }
 
-        // Background nudge: notify on new activity after inactivity threshold in current channel
+        // Removed background nudge notification for generic "new chats!"
-        #if os(iOS)
-        if UIApplication.shared.applicationState != .active {
-            let channelKey: String = {
-                switch activeChannel {
-                case .mesh: return "mesh"
-                case .location(let ch): return "geo:\(ch.geohash)"
-                }
-            }()
-            let now = Date()
-            if let last = lastPublicActivityAt[channelKey], now.timeIntervalSince(last) >= channelInactivityThreshold {
-                // Optional: simple cooldown to avoid duplicate bursts
-                let lastNotified = lastPublicActivityNotifyAt[channelKey] ?? .distantPast
-                if now.timeIntervalSince(lastNotified) >= 60 {
-                    let title = activeChannelDisplayName()
-                    let body = "new chats!"
-                    if case .location(let ch) = activeChannel {
-                        // Attach deep link to open this geohash directly
-                        NotificationService.shared.sendGeohashActivityNotification(geohash: ch.geohash, titlePrefix: title + " ", bodyPreview: body)
-                    } else {
-                        NotificationService.shared.sendLocalNotification(title: title, body: body, identifier: "channel-activity-\(channelKey)-\(now.timeIntervalSince1970)")
-                    }
-                    lastPublicActivityNotifyAt[channelKey] = now
-                }
-            }
-            lastPublicActivityAt[channelKey] = now
-        }
-        #endif
 
-        // Append via batching buffer (skip empty content)
+        // Append via batching buffer (skip empty content) with simple dedup by ID
         if !finalMessage.content.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty {
-            enqueuePublic(finalMessage)
+            if !messages.contains(where: { $0.id == finalMessage.id }) {
+                enqueuePublic(finalMessage)
+            }
         }
     }
 

bitchat/Views/ContentView.swift

@@ -24,6 +24,7 @@ struct ContentView: View {
     
     @EnvironmentObject var viewModel: ChatViewModel
     @ObservedObject private var locationManager = LocationChannelManager.shared
+    @ObservedObject private var bookmarks = GeohashBookmarksStore.shared
     @State private var messageText = ""
     @State private var textFieldSelection: NSRange? = nil
     @FocusState private var isTextFieldFocused: Bool
@@ -164,6 +165,8 @@ struct ContentView: View {
         }
         .sheet(isPresented: $showAppInfo) {
             AppInfoView()
+                .onAppear { viewModel.isAppInfoPresented = true }
+                .onDisappear { viewModel.isAppInfoPresented = false }
         }
         .sheet(isPresented: Binding(
             get: { viewModel.showingFingerprintFor != nil },
@@ -278,8 +281,10 @@ struct ContentView: View {
                         }
                     }()
                     let items = windowedMessages.map { (uiID: "\(contextKey)|\($0.id)", message: $0) }
-                    
+                    // Filter out empty/whitespace-only messages to avoid blank rows
-                    ForEach(items, id: \.uiID) { item in
+                    let filteredItems = items.filter { !$0.message.content.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty }
+
+                    ForEach(filteredItems, id: \.uiID) { item in
                         let message = item.message
                         VStack(alignment: .leading, spacing: 0) {
                             // Check if current user is mentioned
@@ -298,10 +303,21 @@ struct ContentView: View {
                                     HStack(alignment: .top, spacing: 0) {
                                         let isLong = (message.content.count > TransportConfig.uiLongMessageLengthThreshold || message.content.hasVeryLongToken(threshold: TransportConfig.uiVeryLongTokenThreshold)) && cashuTokens.isEmpty
                                         let isExpanded = expandedMessageIDs.contains(message.id)
-                                        Text(viewModel.formatMessageAsText(message, colorScheme: colorScheme))
+                                        let formatted = viewModel.formatMessageAsText(message, colorScheme: colorScheme)
-                                            .fixedSize(horizontal: false, vertical: true)
+                                        let prefixAttr = viewModel.formatSenderPrefix(message, colorScheme: colorScheme)
+                                        let baseColor = viewModel.baseColorForMessage(message, colorScheme: colorScheme)
+                                        let isSelfMsg = viewModel.isSelfMessage(message)
+                                        if (message.isMiningPow ?? false) {
+                                            // Single Text combines prefix + animated body, so wrapping matches final layout
+                                            CombinedMiningText(prefix: prefixAttr, original: message.content, color: baseColor, isSelf: isSelfMsg)
                                             .lineLimit(isLong && !isExpanded ? TransportConfig.uiLongMessageLineLimit : nil)
                                             .frame(maxWidth: .infinity, alignment: .leading)
+                                        } else {
+                                            Text(formatted)
+                                                .fixedSize(horizontal: false, vertical: true)
+                                                .lineLimit(isLong && !isExpanded ? TransportConfig.uiLongMessageLineLimit : nil)
+                                                .frame(maxWidth: .infinity, alignment: .leading)
+                                        }
                                         
                                         // Delivery status indicator for private messages
                                         if message.isPrivate && message.sender == viewModel.nickname,
@@ -459,7 +475,13 @@ struct ContentView: View {
                 }
                 let level = levelForLength(gh.count)
                 let ch = GeohashChannel(level: level, geohash: gh)
-                LocationChannelManager.shared.markTeleported(for: gh, true)
+                // Do not mark teleported when opening a geohash that is in our regional set.
+                // If availableChannels is empty (e.g., cold start), defer marking and let
+                // LocationChannelManager compute teleported based on actual location.
+                let inRegional = LocationChannelManager.shared.availableChannels.contains { $0.geohash == gh }
+                if !inRegional && !LocationChannelManager.shared.availableChannels.isEmpty {
+                    LocationChannelManager.shared.markTeleported(for: gh, true)
+                }
                 LocationChannelManager.shared.select(ChannelID.location(ch))
             }
             .onTapGesture(count: 3) {
@@ -1112,6 +1134,15 @@ struct ContentView: View {
                     .buttonStyle(.plain)
                     .accessibilityLabel("Open unread private chat")
                 }
+                // Bookmark toggle for current geohash (not shown for mesh)
+                if case .location(let ch) = locationManager.selectedChannel {
+                    Button(action: { GeohashBookmarksStore.shared.toggle(ch.geohash) }) {
+                        Image(systemName: GeohashBookmarksStore.shared.isBookmarked(ch.geohash) ? "bookmark.fill" : "bookmark")
+                            .font(.system(size: 12))
+                    }
+                    .buttonStyle(.plain)
+                    .accessibilityLabel("Toggle bookmark for #\(ch.geohash)")
+                }
                 // Location channels button '#'
                 Button(action: { showLocationChannelsSheet = true }) {
                     let badgeText: String = {
@@ -1166,6 +1197,13 @@ struct ContentView: View {
         .padding(.horizontal, 12)
         .sheet(isPresented: $showLocationChannelsSheet) {
             LocationChannelsSheet(isPresented: $showLocationChannelsSheet)
+                .onAppear { viewModel.isLocationChannelsSheetPresented = true }
+                .onDisappear { viewModel.isLocationChannelsSheetPresented = false }
+        }
+        .alert("heads up", isPresented: $viewModel.showScreenshotPrivacyWarning) {
+            Button("ok", role: .cancel) {}
+        } message: {
+            Text("screenshots of location channels will reveal your location. think before sharing publicly.")
         }
         .background(backgroundColor.opacity(0.95))
     }
@@ -1360,6 +1398,53 @@ struct ContentView: View {
     
 }
 
+// MARK: - Mining UI helpers (local to ensure inclusion in target)
+fileprivate struct CombinedMiningText: View {
+    let prefix: AttributedString
+    let original: String
+    let color: Color
+    let isSelf: Bool
+    let fontSize: CGFloat = 14
+    let interval: TimeInterval = 0.06
+    @State private var display: String = ""
+    @State private var timer: Timer? = nil
+
+    private let charset: [Character] = Array("abcdefghijklmnopqrstuvwxyz0123456789@#$%&*+-")
+
+    var body: some View {
+        Text(combinedAttributed)
+            .fixedSize(horizontal: false, vertical: true)
+            .onAppear {
+                display = scramble(original)
+                timer?.invalidate()
+                timer = Timer.scheduledTimer(withTimeInterval: interval, repeats: true) { _ in
+                    display = scramble(original)
+                }
+            }
+            .onDisappear { timer?.invalidate(); timer = nil }
+    }
+
+    private var combinedAttributed: AttributedString {
+        var res = AttributedString()
+        res.append(prefix)
+        var style = AttributeContainer()
+        style.foregroundColor = color
+        style.font = .system(size: fontSize, weight: isSelf ? .bold : .regular, design: .monospaced)
+        res.append(AttributedString(display).mergingAttributes(style))
+        return res
+    }
+
+    private func scramble(_ s: String) -> String {
+        var out = String()
+        out.reserveCapacity(s.count)
+        for ch in s {
+            if ch.isWhitespace || ch.isNewline { out.append(ch); continue }
+            out.append(charset.randomElement() ?? ch)
+        }
+        return out
+    }
+}
+
 // MARK: - Helper Views
 
 // Rounded payment chip button

bitchat/Views/LocationChannelsSheet.swift

@@ -8,6 +8,7 @@ import AppKit
 struct LocationChannelsSheet: View {
     @Binding var isPresented: Bool
     @ObservedObject private var manager = LocationChannelManager.shared
+    @ObservedObject private var bookmarks = GeohashBookmarksStore.shared
     @EnvironmentObject var viewModel: ChatViewModel
     @Environment(\.colorScheme) var colorScheme
     @State private var customGeohash: String = ""
@@ -98,7 +99,7 @@ struct LocationChannelsSheet: View {
 
     private var channelList: some View {
         List {
-            // Mesh option first
+            // Mesh option first (no bookmark)
             channelRow(title: meshTitleWithCount(), subtitlePrefix: "#bluetooth • \(bluetoothRangeString())", isSelected: isMeshSelected, titleColor: standardBlue, titleBold: meshCount() > 0) {
                 manager.select(ChannelID.mesh)
                 isPresented = false
@@ -112,7 +113,21 @@ struct LocationChannelsSheet: View {
                     let namePart = nameBase.map { formattedNamePrefix(for: channel.level) + $0 }
                     let subtitlePrefix = "#\(channel.geohash) • \(coverage)"
                     let highlight = viewModel.geohashParticipantCount(for: channel.geohash) > 0
-                    channelRow(title: geohashTitleWithCount(for: channel), subtitlePrefix: subtitlePrefix, subtitleName: namePart, isSelected: isSelected(channel), titleBold: highlight) {
+                    channelRow(
+                        title: geohashTitleWithCount(for: channel),
+                        subtitlePrefix: subtitlePrefix,
+                        subtitleName: namePart,
+                        isSelected: isSelected(channel),
+                        titleBold: highlight,
+                        trailingAccessory: {
+                            Button(action: { bookmarks.toggle(channel.geohash) }) {
+                                Image(systemName: bookmarks.isBookmarked(channel.geohash) ? "bookmark.fill" : "bookmark")
+                                    .font(.system(size: 14))
+                            }
+                            .buttonStyle(.plain)
+                            .padding(.leading, 8)
+                        }
+                    ) {
                         // Selecting a suggested nearby channel is not a teleport. Persist this.
                         manager.markTeleported(for: channel.geohash, false)
                         manager.select(ChannelID.location(channel))
@@ -188,6 +203,48 @@ struct LocationChannelsSheet: View {
                 }
             }
 
+            // Bookmarked geohashes
+            if !bookmarks.bookmarks.isEmpty {
+                VStack(alignment: .leading, spacing: 6) {
+                    Text("bookmarked")
+                        .font(.system(size: 12, design: .monospaced))
+                        .foregroundColor(.secondary)
+                }
+                .listRowSeparator(.hidden)
+                ForEach(bookmarks.bookmarks, id: \.self) { gh in
+                    let level = levelForLength(gh.count)
+                    let channel = GeohashChannel(level: level, geohash: gh)
+                    let coverage = coverageString(forPrecision: gh.count)
+                    let subtitle = "#\(gh) • \(coverage)"
+                    let name = bookmarks.bookmarkNames[gh]
+                    channelRow(
+                        title: geohashHashTitleWithCount(gh),
+                        subtitlePrefix: subtitle,
+                        subtitleName: name.map { formattedNamePrefix(for: level) + $0 },
+                        isSelected: isSelected(channel),
+                        trailingAccessory: {
+                            Button(action: { bookmarks.toggle(gh) }) {
+                                Image(systemName: bookmarks.isBookmarked(gh) ? "bookmark.fill" : "bookmark")
+                                    .font(.system(size: 14))
+                            }
+                            .buttonStyle(.plain)
+                            .padding(.leading, 8)
+                        }
+                    ) {
+                        // For bookmarked selection, mark teleported based on regional membership
+                        let inRegional = manager.availableChannels.contains { $0.geohash == gh }
+                        if !inRegional && !manager.availableChannels.isEmpty {
+                            manager.markTeleported(for: gh, true)
+                        } else {
+                            manager.markTeleported(for: gh, false)
+                        }
+                        manager.select(ChannelID.location(channel))
+                        isPresented = false
+                    }
+                    .onAppear { bookmarks.resolveNameIfNeeded(for: gh) }
+                }
+            }
+
             // Footer action inside the list
             if manager.permissionState == LocationChannelManager.PermissionState.authorized {
                 Button(action: {
@@ -220,14 +277,24 @@ struct LocationChannelsSheet: View {
         return false
     }
 
-    private func channelRow(title: String, subtitlePrefix: String, subtitleName: String? = nil, subtitleNameBold: Bool = false, isSelected: Bool, titleColor: Color? = nil, titleBold: Bool = false, action: @escaping () -> Void) -> some View {
+    @ViewBuilder
-        Button(action: action) {
+    private func channelRow(
-            HStack {
+        title: String,
-                VStack(alignment: .leading) {
+        subtitlePrefix: String,
-                    // Render title with smaller font for trailing count in parentheses
+        subtitleName: String? = nil,
-                    let parts = splitTitleAndCount(title)
+        subtitleNameBold: Bool = false,
-                    HStack(spacing: 4) {
+        isSelected: Bool,
-                        Text(parts.base)
+        titleColor: Color? = nil,
+        titleBold: Bool = false,
+        @ViewBuilder trailingAccessory: () -> some View = { EmptyView() },
+        action: @escaping () -> Void
+    ) -> some View {
+        HStack(alignment: .center, spacing: 8) {
+            VStack(alignment: .leading) {
+                // Render title with smaller font for trailing count in parentheses
+                let parts = splitTitleAndCount(title)
+                HStack(spacing: 4) {
+                    Text(parts.base)
                             .font(.system(size: 14, design: .monospaced))
                             .fontWeight(titleBold ? .bold : .regular)
                             .foregroundColor(titleColor ?? Color.primary)
@@ -237,20 +304,17 @@ struct LocationChannelsSheet: View {
                                 .foregroundColor(.secondary)
                         }
                     }
-                    HStack(spacing: 0) {
+                let subtitleFull: String = {
-                        Text(subtitlePrefix)
+                    if let name = subtitleName, !name.isEmpty {
-                            .font(.system(size: 12, design: .monospaced))
+                        return subtitlePrefix + " • " + name
-                            .foregroundColor(.secondary)
-                        if let name = subtitleName {
-                            Text(" • ")
-                                .font(.system(size: 12, design: .monospaced))
-                                .foregroundColor(.secondary)
-                            Text(name)
-                                .font(.system(size: 12, design: .monospaced))
-                                .fontWeight(subtitleNameBold ? .bold : .regular)
-                                .foregroundColor(.secondary)
-                        }
                     }
+                    return subtitlePrefix
+                }()
+                Text(subtitleFull)
+                    .font(.system(size: 12, design: .monospaced))
+                    .foregroundColor(.secondary)
+                    .lineLimit(1)
+                    .truncationMode(.tail)
                 }
                 Spacer()
                 if isSelected {
@@ -258,11 +322,11 @@ struct LocationChannelsSheet: View {
                         .font(.system(size: 16, design: .monospaced))
                         .foregroundColor(standardGreen)
                 }
+                trailingAccessory()
             }
             .frame(maxWidth: .infinity, alignment: .leading)
-            .contentShape(Rectangle())
+        .contentShape(Rectangle())
-        }
+        .onTapGesture(perform: action)
-        .buttonStyle(.plain)
     }
 
     // Split a title like "#mesh [3 people]" into base and suffix "[3 people]"
@@ -291,12 +355,19 @@ struct LocationChannelsSheet: View {
     }
 
     private func geohashTitleWithCount(for channel: GeohashChannel) -> String {
-        // Use ViewModel's 5-minute activity counts; may be 0 for non-selected channels
+        // Main list: keep level labels (block/neighborhood/city/province/region)
         let count = viewModel.geohashParticipantCount(for: channel.geohash)
         let noun = count == 1 ? "person" : "people"
         return "\(channel.level.displayName.lowercased()) [\(count) \(noun)]"
     }
 
+    private func geohashHashTitleWithCount(_ geohash: String) -> String {
+        // Bookmarked list: show the #geohash as the main label
+        let count = viewModel.geohashParticipantCount(for: geohash)
+        let noun = count == 1 ? "person" : "people"
+        return "#\(geohash) [\(count) \(noun)]"
+    }
+
     private func validateGeohash(_ s: String) -> Bool {
         let allowed = Set("0123456789bcdefghjkmnpqrstuvwxyz")
         guard !s.isEmpty, s.count <= 12 else { return false }

bitchat/Views/MiningAnimation.swift

@@ -0,0 +1,87 @@
+import SwiftUI
+
+/// Mining body animation: scramble characters (matrix-like) until PoW completes.
+struct MiningScrambleText: View {
+    let original: String
+    let color: Color
+    let isSelf: Bool
+    let fontSize: CGFloat = 14
+    let interval: TimeInterval = 0.06
+    @State private var display: String = ""
+    @State private var timer: Timer? = nil
+
+    private let charset: [Character] = Array("abcdefghijklmnopqrstuvwxyz0123456789@#$%&*+-")
+
+    var body: some View {
+        Text(display)
+            .font(.system(size: fontSize, weight: isSelf ? .bold : .regular, design: .monospaced))
+            .foregroundColor(color)
+            .onAppear {
+                display = scramble(original)
+                timer?.invalidate()
+                timer = Timer.scheduledTimer(withTimeInterval: interval, repeats: true) { _ in
+                    display = scramble(original)
+                }
+            }
+            .onDisappear {
+                timer?.invalidate(); timer = nil
+            }
+}
+
+/// Combined prefix+body single-Text variant to ensure identical wrapping
+struct MiningCombinedText: View {
+    let prefix: AttributedString
+    let original: String
+    let color: Color
+    let isSelf: Bool
+    let fontSize: CGFloat = 14
+    let interval: TimeInterval = 0.06
+    @State private var display: String = ""
+    @State private var timer: Timer? = nil
+
+    private let charset: [Character] = Array("abcdefghijklmnopqrstuvwxyz0123456789@#$%&*+-")
+
+    var body: some View {
+        Text(combinedAttributed)
+            .fixedSize(horizontal: false, vertical: true)
+            .onAppear {
+                display = scramble(original)
+                timer?.invalidate()
+                timer = Timer.scheduledTimer(withTimeInterval: interval, repeats: true) { _ in
+                    display = scramble(original)
+                }
+            }
+            .onDisappear { timer?.invalidate(); timer = nil }
+    }
+
+    private var combinedAttributed: AttributedString {
+        var res = AttributedString()
+        res.append(prefix)
+        var style = AttributeContainer()
+        style.foregroundColor = color
+        style.font = .system(size: fontSize, weight: isSelf ? .bold : .regular, design: .monospaced)
+        res.append(AttributedString(display).mergingAttributes(style))
+        return res
+    }
+
+    private func scramble(_ s: String) -> String {
+        var out = String()
+        out.reserveCapacity(s.count)
+        for ch in s {
+            if ch.isWhitespace || ch.isNewline { out.append(ch); continue }
+            out.append(charset.randomElement() ?? ch)
+        }
+        return out
+    }
+}
+
+    private func scramble(_ s: String) -> String {
+        var out = String()
+        out.reserveCapacity(s.count)
+        for ch in s {
+            if ch.isWhitespace || ch.isNewline { out.append(ch); continue }
+            out.append(charset.randomElement() ?? ch)
+        }
+        return out
+    }
+}

bitchatTests/GeohashBookmarksStoreTests.swift

@@ -0,0 +1,51 @@
+import XCTest
+@testable import bitchat
+
+final class GeohashBookmarksStoreTests: XCTestCase {
+    let storeKey = "locationChannel.bookmarks"
+
+    override func setUp() {
+        super.setUp()
+        // Clear persisted state before each test
+        UserDefaults.standard.removeObject(forKey: storeKey)
+        GeohashBookmarksStore.shared._resetForTesting()
+    }
+
+    override func tearDown() {
+        // Clean after each test
+        UserDefaults.standard.removeObject(forKey: storeKey)
+        GeohashBookmarksStore.shared._resetForTesting()
+        super.tearDown()
+    }
+
+    func testToggleAndNormalize() {
+        let store = GeohashBookmarksStore.shared
+        // Start clean
+        XCTAssertTrue(store.bookmarks.isEmpty)
+
+        // Add with mixed case and hash prefix
+        store.toggle("#U4PRUY")
+        XCTAssertTrue(store.isBookmarked("u4pruy"))
+        XCTAssertEqual(store.bookmarks.first, "u4pruy")
+
+        // Toggling again removes
+        store.toggle("u4pruy")
+        XCTAssertFalse(store.isBookmarked("u4pruy"))
+        XCTAssertTrue(store.bookmarks.isEmpty)
+    }
+
+    func testPersistenceWritten() throws {
+        let store = GeohashBookmarksStore.shared
+        store.toggle("ezs42")
+        store.toggle("u4pruy")
+
+        // Verify persisted JSON contains both (order not enforced here)
+        guard let data = UserDefaults.standard.data(forKey: storeKey) else {
+            XCTFail("No persisted data found")
+            return
+        }
+        let arr = try JSONDecoder().decode([String].self, from: data)
+        XCTAssertTrue(arr.contains("ezs42"))
+        XCTAssertTrue(arr.contains("u4pruy"))
+    }
+}

bitchatTests/Info.plist

@@ -2,17 +2,17 @@
 <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
 <plist version="1.0">
 <dict>
-    <key>CFBundleIdentifier</key>
+	<key>CFBundleIdentifier</key>
-    <string>$(PRODUCT_BUNDLE_IDENTIFIER)</string>
+	<string>$(PRODUCT_BUNDLE_IDENTIFIER)</string>
-    <key>CFBundleInfoDictionaryVersion</key>
+	<key>CFBundleInfoDictionaryVersion</key>
-    <string>6.0</string>
+	<string>6.0</string>
-    <key>CFBundleName</key>
+	<key>CFBundleName</key>
-    <string>$(PRODUCT_NAME)</string>
+	<string>$(PRODUCT_NAME)</string>
-    <key>CFBundlePackageType</key>
+	<key>CFBundlePackageType</key>
-    <string>$(PRODUCT_BUNDLE_PACKAGE_TYPE)</string>
+	<string>$(PRODUCT_BUNDLE_PACKAGE_TYPE)</string>
-    <key>CFBundleShortVersionString</key>
+	<key>CFBundleShortVersionString</key>
-    <string>1.0</string>
+	<string>1.0</string>
-    <key>CFBundleVersion</key>
+	<key>CFBundleVersion</key>
-    <string>1</string>
+	<string>1</string>
 </dict>
-</plist>
+</plist>

bitchatTests/NostrPoWTests.swift

@@ -0,0 +1,32 @@
+import XCTest
+import CryptoKit
+@testable import bitchat
+
+final class NostrPoWTests: XCTestCase {
+    func testLeadingZeroBits() {
+        // 0x00 -> 8, 0x00 -> 8, 0xF0 -> 0 leading zeros
+        let data = Data([0x00, 0x00, 0xF0]) + Data(repeating: 0x00, count: 29)
+        let lz = NostrPoW.leadingZeroBits(data)
+        XCTAssertEqual(lz, 16)
+    }
+
+    func testMineLowDifficulty() {
+        let pubkey = String(repeating: "a", count: 64)
+        let createdAt = Int(Date().timeIntervalSince1970)
+        let kind = 20000
+        let tags = [["g", "u4pruydqqvj"]]
+        let content = "hello"
+        let targetBits = 8 // keep it very low for test speed
+        let (nonce, idHex) = NostrPoW.mine(pubkey: pubkey, createdAt: createdAt, kind: kind, baseTags: tags, content: content, targetBits: targetBits)
+        XCTAssertGreaterThan(nonce, 0)
+        // Verify difficulty
+        let powTags = tags + [["nonce", String(nonce), String(targetBits)]]
+        // Recompute ID
+        let serialized: [Any] = [0, pubkey, createdAt, kind, powTags, content]
+        let json = try! JSONSerialization.data(withJSONObject: serialized, options: [.withoutEscapingSlashes])
+        let digest = CryptoKit.SHA256.hash(data: json)
+        let idData = Data(digest)
+        XCTAssertEqual(idHex.count, 64)
+        XCTAssertGreaterThanOrEqual(NostrPoW.leadingZeroBits(idData), targetBits)
+    }
+}