Update deprecated GitHub Actions

BitFoundation module to centralize shared components (#1089 )
* Run local packages’ tests as well on CI * BitFoundation module to centralize shared components
2026-07-25 09:45:18 +00:00 · 2026-04-14 20:34:30 +01:00 · 2026-04-14 14:10:03 -05:00 · 2026-04-12 06:32:24 +00:00 · 2026-04-10 22:31:49 +01:00 · 2026-04-05 19:04:18 -05:00
2517 changed files with 64158 additions and 389334 deletions
@@ -1,12 +0,0 @@
---
-path:            '/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/swift/macosx/prebuilt-modules/26.0/Swift.swiftmodule/arm64e-apple-macos.swiftmodule'
-dependencies:
-  - mtime:           1757258659000000000
-    path:            '/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/swift/macosx/prebuilt-modules/26.0/Swift.swiftmodule/arm64e-apple-macos.swiftmodule'
-    size:            14166264
-  - mtime:           1754189697000000000
-    path:            'usr/lib/swift/Swift.swiftmodule/arm64e-apple-macos.swiftinterface'
-    size:            2261306
-    sdk_relative:    true
-version:         1
-...
@@ -1,16 +0,0 @@
---
-path:            '/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/swift/macosx/prebuilt-modules/26.0/SwiftOnoneSupport.swiftmodule/arm64e-apple-macos.swiftmodule'
-dependencies:
-  - mtime:           1757258662000000000
-    path:            '/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/swift/macosx/prebuilt-modules/26.0/SwiftOnoneSupport.swiftmodule/arm64e-apple-macos.swiftmodule'
-    size:            18068
-  - mtime:           1754189697000000000
-    path:            'usr/lib/swift/Swift.swiftmodule/arm64e-apple-macos.swiftinterface'
-    size:            2261306
-    sdk_relative:    true
-  - mtime:           1754191141000000000
-    path:            'usr/lib/swift/SwiftOnoneSupport.swiftmodule/arm64e-apple-macos.swiftinterface'
-    size:            1224
-    sdk_relative:    true
-version:         1
-...
@@ -1,16 +0,0 @@
---
-path:            '/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/swift/macosx/prebuilt-modules/26.0/_Concurrency.swiftmodule/arm64e-apple-macos.swiftmodule'
-dependencies:
-  - mtime:           1757258669000000000
-    path:            '/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/swift/macosx/prebuilt-modules/26.0/_Concurrency.swiftmodule/arm64e-apple-macos.swiftmodule'
-    size:            699544
-  - mtime:           1754189697000000000
-    path:            'usr/lib/swift/Swift.swiftmodule/arm64e-apple-macos.swiftinterface'
-    size:            2261306
-    sdk_relative:    true
-  - mtime:           1754192470000000000
-    path:            'usr/lib/swift/_Concurrency.swiftmodule/arm64e-apple-macos.swiftinterface'
-    size:            364219
-    sdk_relative:    true
-version:         1
-...
@@ -1,16 +0,0 @@
---
-path:            '/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/swift/macosx/prebuilt-modules/26.0/_StringProcessing.swiftmodule/arm64e-apple-macos.swiftmodule'
-dependencies:
-  - mtime:           1757258664000000000
-    path:            '/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/swift/macosx/prebuilt-modules/26.0/_StringProcessing.swiftmodule/arm64e-apple-macos.swiftmodule'
-    size:            83568
-  - mtime:           1754189697000000000
-    path:            'usr/lib/swift/Swift.swiftmodule/arm64e-apple-macos.swiftinterface'
-    size:            2261306
-    sdk_relative:    true
-  - mtime:           1754192532000000000
-    path:            'usr/lib/swift/_StringProcessing.swiftmodule/arm64e-apple-macos.swiftinterface'
-    size:            24507
-    sdk_relative:    true
-version:         1
-...
@@ -7,6 +7,7 @@ on:

 permissions:
  contents: write
+  pull-requests: write

 jobs:
  update-relay-data:
@@ -17,10 +18,11 @@ jobs:
        uses: actions/checkout@v4
        with:
          token: ${{ secrets.GITHUB_TOKEN }}
-      
+          fetch-depth: 0
+
      - name: Fetch GeoRelays
        run: |
-          wget https://raw.githubusercontent.com/permissionlesstech/georelays/refs/heads/main/nostr_relays.csv
+          wget -q https://raw.githubusercontent.com/permissionlesstech/georelays/refs/heads/main/nostr_relays.csv
          mv nostr_relays.csv ./relays/online_relays_gps.csv

      - name: Check for changes
@@ -5,23 +5,38 @@ on:
    branches:
      - main
  pull_request:
-    branches:
-      - main

 jobs:
  test:
-    name: Run Swift Tests
+    name: Run Swift Tests (${{ matrix.name }})
    runs-on: macos-latest

+    strategy:
+      fail-fast: false # Don't cancel other matrix jobs when one fails
+      matrix:
+        include:
+          - name: app
+            path: .
+          - name: BitLogger
+            path: localPackages/BitLogger
+          - name: BitFoundation
+            path: localPackages/BitFoundation
+
    steps:
      - name: Checkout code
        uses: actions/checkout@v5

      - name: Set up Swift
-        uses: swift-actions/setup-swift@v2
+        uses: swift-actions/setup-swift@v3

-      - name: Build the package
-        run: swift build
+      - name: Cache build artifacts
+        uses: actions/cache@v5
+        with:
+          path: ${{ matrix.path }}/.build
+          key: ${{ runner.os }}-${{ matrix.name }}-${{ hashFiles(format('{0}/**/*.swift', matrix.path), format('{0}/**/Package.resolved', matrix.path)) }}
+          restore-keys: |
+            ${{ runner.os }}-${{ matrix.name }}-${{ hashFiles(format('{0}/**/Package.resolved', matrix.path)) }}
+            ${{ runner.os }}-${{ matrix.name }}-

      - name: Run Tests
-        run: swift test --parallel
+        run: swift test --parallel --quiet --package-path ${{ matrix.path }}
@@ -8,6 +8,7 @@ plans/
 ## AI
 CLAUDE.md
 AGENTS.md
+.claude/

 ## compatibility with Xcode 8 and earlier (ignoring not required starting Xcode 9)
 *.xcscmblueprint
@@ -66,6 +67,9 @@ __pycache__/
 *.tmp
 *.temp

+## Cache
+.cache/
+
 # Local build results
 .Result*/
 .Result*.xcresult/
@@ -1,4 +1,4 @@
-MARKETING_VERSION = 1.4.4
+MARKETING_VERSION = 1.5.1
 CURRENT_PROJECT_VERSION = 1

 IPHONEOS_DEPLOYMENT_TARGET = 16.0
@@ -9,3 +9,4 @@ DEVELOPMENT_TEAM = L3N5LHJD5Y
 CODE_SIGN_STYLE = Automatic

 PRODUCT_BUNDLE_IDENTIFIER = chat.bitchat
+APP_GROUP_ID = group.chat.bitchat
@@ -14,8 +14,11 @@ default:
 # Check prerequisites
 check:
    @echo "Checking prerequisites..."
-    @command -v xcodebuild >/dev/null 2>&1 || (echo "❌ Xcode not found. Install Xcode from App Store" && exit 1)
-    @security find-identity -v -p codesigning | grep -q "Developer ID" || (echo "⚠️  No Developer ID found - code signing may fail" && exit 0)
+    @command -v xcodebuild >/dev/null 2>&1 || (echo "❌ xcodebuild not found. Install Xcode from App Store" && exit 1)
+    @xcode-select -p | grep -q "Xcode.app" || (echo "❌ Full Xcode required, not just command line tools. Install from App Store and run:\n   sudo xcode-select -s /Applications/Xcode.app/Contents/Developer" && exit 1)
+    @test -d "/Applications/Xcode.app" || (echo "❌ Xcode.app not found in Applications folder. Install from App Store" && exit 1)
+    @xcodebuild -version >/dev/null 2>&1 || (echo "❌ Xcode not properly configured. Try:\n   sudo xcode-select -s /Applications/Xcode.app/Contents/Developer" && exit 1)
+    @security find-identity -v -p codesigning | grep -q "Apple Development\|Developer ID" || (echo "⚠️  No Developer ID found - code signing may fail" && exit 0)
    @echo "✅ All prerequisites met"

 # Backup original files
@@ -44,7 +47,7 @@ patch-for-macos: backup
 # Build the macOS app
 build: #check generate
    @echo "Building BitChat for macOS..."
-    @xcodebuild -project bitchat.xcodeproj -scheme "bitchat_macOS" -configuration Debug CODE_SIGN_IDENTITY="" CODE_SIGNING_REQUIRED=NO CODE_SIGN_ENTITLEMENTS="" build
+    @xcodebuild -project bitchat.xcodeproj -scheme "bitchat (macOS)" -configuration Debug CODE_SIGN_IDENTITY="" CODE_SIGNING_REQUIRED=NO CODE_SIGN_ENTITLEMENTS="" build

 # Run the macOS app
 run: build
@@ -16,7 +16,8 @@ let package = Package(
        ),
    ],
    dependencies:[
-        .package(path: "localPackages/Tor"),
+        .package(path: "localPackages/Arti"),
+        .package(path: "localPackages/BitFoundation"),
        .package(path: "localPackages/BitLogger"),
        .package(url: "https://github.com/21-DOT-DEV/swift-secp256k1", exact: "0.21.1")
    ],
@@ -25,16 +26,19 @@ let package = Package(
            name: "bitchat",
            dependencies: [
                .product(name: "P256K", package: "swift-secp256k1"),
+                .product(name: "BitFoundation", package: "BitFoundation"),
                .product(name: "BitLogger", package: "BitLogger"),
-                .product(name: "Tor", package: "Tor")
+                .product(name: "Tor", package: "Arti")
            ],
            path: "bitchat",
            exclude: [
                "Info.plist",
                "Assets.xcassets",
+                "_PreviewHelpers/PreviewAssets.xcassets",
                "bitchat.entitlements",
                "bitchat-macOS.entitlements",
-                "LaunchScreen.storyboard"
+                "LaunchScreen.storyboard",
+                "ViewModels/Extensions/README.md"
            ],
            resources: [
                .process("Localizable.xcstrings")
@@ -42,14 +46,18 @@ let package = Package(
        ),
        .testTarget(
            name: "bitchatTests",
-            dependencies: ["bitchat"],
+            dependencies: [
+                "bitchat",
+                .product(name: "BitFoundation", package: "BitFoundation")
+            ],
            path: "bitchatTests",
            exclude: [
                "Info.plist",
                "README.md"
            ],
            resources: [
-                .process("Localization")
+                .process("Localization"),
+                .process("Noise")
            ]
        )
    ]
@@ -8,9 +8,6 @@ A decentralized peer-to-peer messaging app with dual transport architecture: loc

 📲 [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](https://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.
@@ -10,11 +10,12 @@
 		17901751FD8010AFC8E750F2 /* bitchatShareExtension.appex in Embed Foundation Extensions */ = {isa = PBXBuildFile; fileRef = 61F92EBA29C47C0FCC482F1F /* bitchatShareExtension.appex */; settings = {ATTRIBUTES = (RemoveHeadersOnCopy, ); }; };
 		3EE336D150427F736F32B56C /* P256K in Frameworks */ = {isa = PBXBuildFile; productRef = B1D9136AA0083366353BFA2F /* P256K */; };
 		885BBED78092484A5B069461 /* P256K in Frameworks */ = {isa = PBXBuildFile; productRef = 4EB6BA1B8464F1EA38F4E286 /* P256K */; };
+		A6BCF9482F80953E001CF9B9 /* BitFoundation in Frameworks */ = {isa = PBXBuildFile; productRef = A6BCF9472F80953E001CF9B9 /* BitFoundation */; };
+		A6BCF94A2F809550001CF9B9 /* BitFoundation in Frameworks */ = {isa = PBXBuildFile; productRef = A6BCF9492F809550001CF9B9 /* BitFoundation */; };
 		A6E3E5702E77036A0032EA8A /* BitLogger in Frameworks */ = {isa = PBXBuildFile; productRef = A6E3E56F2E77036A0032EA8A /* BitLogger */; };
 		A6E3E5722E7703760032EA8A /* BitLogger in Frameworks */ = {isa = PBXBuildFile; productRef = A6E3E5712E7703760032EA8A /* BitLogger */; };
 		A6E3EA7F2E7706720032EA8A /* Tor in Frameworks */ = {isa = PBXBuildFile; productRef = A6E3EA7E2E7706720032EA8A /* Tor */; };
 		A6E3EA812E7706A80032EA8A /* Tor in Frameworks */ = {isa = PBXBuildFile; productRef = A6E3EA802E7706A80032EA8A /* Tor */; };
-		A6F183FD2E948783006A9046 /* tor-nolzma.xcframework in Frameworks */ = {isa = PBXBuildFile; fileRef = A6F183FC2E948783006A9046 /* tor-nolzma.xcframework */; };
 		E0A1B2C3D4E5F6012345678D /* relays/online_relays_gps.csv in Resources */ = {isa = PBXBuildFile; fileRef = E0A1B2C3D4E5F6012345678A /* relays/online_relays_gps.csv */; };
 		E0A1B2C3D4E5F6012345678E /* relays/online_relays_gps.csv in Resources */ = {isa = PBXBuildFile; fileRef = E0A1B2C3D4E5F6012345678A /* relays/online_relays_gps.csv */; };
 /* End PBXBuildFile section */
@@ -95,6 +96,24 @@
 			);
 			target = 57CA17A36A2532A6CFF367BB /* bitchatShareExtension */;
 		};
+		C5E027A52ECCDFD700BD6012 /* Exceptions for "bitchatTests" folder in "bitchatTests_macOS" target */ = {
+			isa = PBXFileSystemSynchronizedBuildFileExceptionSet;
+			membershipExceptions = (
+				Info.plist,
+				Localization/PrimaryLocalizationKeys.json,
+				README.md,
+			);
+			target = 47FF23248747DD7CB666CB91 /* bitchatTests_macOS */;
+		};
+		C5E027A82ECCDFE200BD6012 /* Exceptions for "bitchatTests" folder in "bitchatTests_iOS" target */ = {
+			isa = PBXFileSystemSynchronizedBuildFileExceptionSet;
+			membershipExceptions = (
+				Info.plist,
+				Localization/PrimaryLocalizationKeys.json,
+				README.md,
+			);
+			target = 6CB97DF2EA57234CB3E563B8 /* bitchatTests_iOS */;
+		};
 /* End PBXFileSystemSynchronizedBuildFileExceptionSet section */

 /* Begin PBXFileSystemSynchronizedRootGroup section */
@@ -118,6 +137,10 @@
 		};
 		A6E32D412E762EAE0032EA8A /* bitchatTests */ = {
 			isa = PBXFileSystemSynchronizedRootGroup;
+			exceptions = (
+				C5E027A82ECCDFE200BD6012 /* Exceptions for "bitchatTests" folder in "bitchatTests_iOS" target */,
+				C5E027A52ECCDFD700BD6012 /* Exceptions for "bitchatTests" folder in "bitchatTests_macOS" target */,
+			);
 			path = bitchatTests;
 			sourceTree = "<group>";
 		};
@@ -135,15 +158,16 @@
 				A6E3E5722E7703760032EA8A /* BitLogger in Frameworks */,
 				3EE336D150427F736F32B56C /* P256K in Frameworks */,
 				A6E3EA812E7706A80032EA8A /* Tor in Frameworks */,
+				A6BCF94A2F809550001CF9B9 /* BitFoundation in Frameworks */,
 			);
 		};
 		B5A5CC493FFB3D8966548140 /* Frameworks */ = {
 			isa = PBXFrameworksBuildPhase;
 			files = (
-				A6F183FD2E948783006A9046 /* tor-nolzma.xcframework in Frameworks */,
 				A6E3E5702E77036A0032EA8A /* BitLogger in Frameworks */,
 				885BBED78092484A5B069461 /* P256K in Frameworks */,
 				A6E3EA7F2E7706720032EA8A /* Tor in Frameworks */,
+				A6BCF9482F80953E001CF9B9 /* BitFoundation in Frameworks */,
 			);
 		};
 /* End PBXFrameworksBuildPhase section */
@@ -203,6 +227,7 @@
 				B1D9136AA0083366353BFA2F /* P256K */,
 				A6E3E5712E7703760032EA8A /* BitLogger */,
 				A6E3EA802E7706A80032EA8A /* Tor */,
+				A6BCF9492F809550001CF9B9 /* BitFoundation */,
 			);
 			productName = bitchat_macOS;
 			productReference = 8F3A7C058C2C8E1A06C8CF8B /* bitchat.app */;
@@ -213,6 +238,7 @@
 			buildConfigurationList = 1C27B5BA3DB46DDF0DBFEF62 /* Build configuration list for PBXNativeTarget "bitchatTests_macOS" */;
 			buildPhases = (
 				5C22AA7B9ACC5A861445C769 /* Sources */,
+				C5E027A42ECCDFD700BD6012 /* Resources */,
 			);
 			buildRules = (
 			);
@@ -245,6 +271,7 @@
 			buildConfigurationList = 38C4AF6313E5037F25CEF30B /* Build configuration list for PBXNativeTarget "bitchatTests_iOS" */;
 			buildPhases = (
 				865C8403EF02C089369A9FCB /* Sources */,
+				C5E027A72ECCDFE200BD6012 /* Resources */,
 			);
 			buildRules = (
 			);
@@ -281,6 +308,7 @@
 				4EB6BA1B8464F1EA38F4E286 /* P256K */,
 				A6E3E56F2E77036A0032EA8A /* BitLogger */,
 				A6E3EA7E2E7706720032EA8A /* Tor */,
+				A6BCF9472F80953E001CF9B9 /* BitFoundation */,
 			);
 			productName = bitchat_iOS;
 			productReference = 96D0D41CA19EE5A772AA8434 /* bitchat.app */;
@@ -312,6 +340,7 @@
 				ne,
 				"pt-BR",
 				ru,
+				tr,
 				uk,
 				"zh-Hans",
 			);
@@ -320,7 +349,8 @@
 			packageReferences = (
 				B8C407587481BBB190741C93 /* XCRemoteSwiftPackageReference "swift-secp256k1" */,
 				A6E3E56E2E77036A0032EA8A /* XCLocalSwiftPackageReference "localPackages/BitLogger" */,
-				A6E3EA7D2E7706720032EA8A /* XCLocalSwiftPackageReference "localPackages/Tor" */,
+				A6E3EA7D2E7706720032EA8A /* XCLocalSwiftPackageReference "localPackages/Arti" */,
+				A6BCF9462F80953E001CF9B9 /* XCLocalSwiftPackageReference "localPackages/BitFoundation" */,
 			);
 			preferredProjectObjectVersion = 90;
 			projectDirPath = "";
@@ -342,6 +372,16 @@
 				E0A1B2C3D4E5F6012345678D /* relays/online_relays_gps.csv in Resources */,
 			);
 		};
+		C5E027A42ECCDFD700BD6012 /* Resources */ = {
+			isa = PBXResourcesBuildPhase;
+			files = (
+			);
+		};
+		C5E027A72ECCDFE200BD6012 /* Resources */ = {
+			isa = PBXResourcesBuildPhase;
+			files = (
+			);
+		};
 		CD6E8F32BC38357473954F97 /* Resources */ = {
 			isa = PBXResourcesBuildPhase;
 			files = (
@@ -515,6 +555,7 @@
 				CODE_SIGNING_REQUIRED = YES;
 				CODE_SIGN_ENTITLEMENTS = bitchat/bitchat.entitlements;
 				CODE_SIGN_STYLE = "$(CODE_SIGN_STYLE)";
+				DEVELOPMENT_ASSET_PATHS = bitchat/_PreviewHelpers;
 				DEVELOPMENT_TEAM = "$(DEVELOPMENT_TEAM)";
 				ENABLE_PREVIEWS = NO;
 				INFOPLIST_FILE = bitchat/Info.plist;
@@ -525,7 +566,7 @@
 					"$(inherited)",
 					"@executable_path/Frameworks",
 				);
-				MARKETING_VERSION = "$(MARKETING_VERSION)";
+				MARKETING_VERSION = 1.5.1;
 				PRODUCT_BUNDLE_IDENTIFIER = "$(PRODUCT_BUNDLE_IDENTIFIER)";
 				PRODUCT_NAME = bitchat;
 				SDKROOT = iphoneos;
@@ -575,6 +616,7 @@
 				CODE_SIGNING_REQUIRED = YES;
 				CODE_SIGN_ENTITLEMENTS = bitchat/bitchat.entitlements;
 				CODE_SIGN_STYLE = "$(CODE_SIGN_STYLE)";
+				DEVELOPMENT_ASSET_PATHS = bitchat/_PreviewHelpers;
 				DEVELOPMENT_TEAM = "$(DEVELOPMENT_TEAM)";
 				ENABLE_PREVIEWS = YES;
 				INFOPLIST_FILE = bitchat/Info.plist;
@@ -585,7 +627,7 @@
 					"$(inherited)",
 					"@executable_path/Frameworks",
 				);
-				MARKETING_VERSION = "$(MARKETING_VERSION)";
+				MARKETING_VERSION = 1.5.1;
 				PRODUCT_BUNDLE_IDENTIFIER = "$(PRODUCT_BUNDLE_IDENTIFIER)";
 				PRODUCT_NAME = bitchat;
 				SDKROOT = iphoneos;
@@ -621,7 +663,7 @@
 					"@executable_path/../Frameworks",
 				);
 				MACOSX_DEPLOYMENT_TARGET = "$(MACOSX_DEPLOYMENT_TARGET)";
-				MARKETING_VERSION = "$(MARKETING_VERSION)";
+				MARKETING_VERSION = 1.5.1;
 				PRODUCT_BUNDLE_IDENTIFIER = "$(PRODUCT_BUNDLE_IDENTIFIER)";
 				PRODUCT_NAME = bitchat;
 				REGISTER_APP_GROUPS = YES;
@@ -713,7 +755,7 @@
 					"@executable_path/../Frameworks",
 				);
 				MACOSX_DEPLOYMENT_TARGET = "$(MACOSX_DEPLOYMENT_TARGET)";
-				MARKETING_VERSION = "$(MARKETING_VERSION)";
+				MARKETING_VERSION = 1.5.1;
 				PRODUCT_BUNDLE_IDENTIFIER = "$(PRODUCT_BUNDLE_IDENTIFIER)";
 				PRODUCT_NAME = bitchat;
 				REGISTER_APP_GROUPS = YES;
@@ -874,13 +916,17 @@
 /* End XCConfigurationList section */

 /* Begin XCLocalSwiftPackageReference section */
+		A6BCF9462F80953E001CF9B9 /* XCLocalSwiftPackageReference "localPackages/BitFoundation" */ = {
+			isa = XCLocalSwiftPackageReference;
+			relativePath = localPackages/BitFoundation;
+		};
 		A6E3E56E2E77036A0032EA8A /* XCLocalSwiftPackageReference "localPackages/BitLogger" */ = {
 			isa = XCLocalSwiftPackageReference;
 			relativePath = localPackages/BitLogger;
 		};
-		A6E3EA7D2E7706720032EA8A /* XCLocalSwiftPackageReference "localPackages/Tor" */ = {
+		A6E3EA7D2E7706720032EA8A /* XCLocalSwiftPackageReference "localPackages/Arti" */ = {
 			isa = XCLocalSwiftPackageReference;
-			relativePath = localPackages/Tor;
+			relativePath = localPackages/Arti;
 		};
 /* End XCLocalSwiftPackageReference section */

@@ -889,8 +935,8 @@
 			isa = XCRemoteSwiftPackageReference;
 			repositoryURL = "https://github.com/21-DOT-DEV/swift-secp256k1";
 			requirement = {
-				kind = upToNextMajorVersion;
-				minimumVersion = 0.21.1;
+				kind = exactVersion;
+				version = 0.21.1;
 			};
 		};
 /* End XCRemoteSwiftPackageReference section */
@@ -901,6 +947,15 @@
 			package = B8C407587481BBB190741C93 /* XCRemoteSwiftPackageReference "swift-secp256k1" */;
 			productName = P256K;
 		};
+		A6BCF9472F80953E001CF9B9 /* BitFoundation */ = {
+			isa = XCSwiftPackageProductDependency;
+			productName = BitFoundation;
+		};
+		A6BCF9492F809550001CF9B9 /* BitFoundation */ = {
+			isa = XCSwiftPackageProductDependency;
+			package = A6BCF9462F80953E001CF9B9 /* XCLocalSwiftPackageReference "localPackages/BitFoundation" */;
+			productName = BitFoundation;
+		};
 		A6E3E56F2E77036A0032EA8A /* BitLogger */ = {
 			isa = XCSwiftPackageProductDependency;
 			productName = BitLogger;
@@ -98,8 +98,8 @@
      </BuildableProductRunnable>
      <EnvironmentVariables>
         <EnvironmentVariable
-            key = "-DBITCHAT_DEV_ALLOW_CLEARNET"
-            value = ""
+            key = "BITCHAT_LOG_LEVEL"
+            value = "debug"
            isEnabled = "YES">
         </EnvironmentVariable>
      </EnvironmentVariables>
@@ -13,7 +13,6 @@
          "value" : "dark"
        }
      ],
-      "filename" : "image-1024 1.png",
      "idiom" : "universal",
      "platform" : "ios",
      "size" : "1024x1024"
@@ -25,7 +24,6 @@
          "value" : "tinted"
        }
      ],
-      "filename" : "image-1024 2.png",
      "idiom" : "universal",
      "platform" : "ios",
      "size" : "1024x1024"
@@ -8,6 +8,7 @@

 import Tor
 import SwiftUI
+import BitFoundation
 import UserNotifications

@main
@@ -26,11 +27,15 @@ struct BitchatApp: App {
    @NSApplicationDelegateAdaptor(MacAppDelegate.self) var appDelegate
    #endif
    
+    private let idBridge = NostrIdentityBridge()
+    
    init() {
        let keychain = KeychainManager()
+        let idBridge = self.idBridge
        _chatViewModel = StateObject(
            wrappedValue: ChatViewModel(
                keychain: keychain,
+                idBridge: idBridge,
                identityManager: SecureIdentityStateManager(keychain)
            )
        )
@@ -49,17 +54,20 @@ struct BitchatApp: App {
                    // Inject live Noise service into VerificationService to avoid creating new BLE instances
                    VerificationService.shared.configure(with: chatViewModel.meshService.getNoiseService())
                    // Prewarm Nostr identity and QR to make first VERIFY sheet fast
+                    let nickname = chatViewModel.nickname
                    DispatchQueue.global(qos: .utility).async {
-                        let npub = try? NostrIdentityBridge.getCurrentNostrIdentity()?.npub
-                        _ = VerificationService.shared.buildMyQRString(nickname: chatViewModel.nickname, npub: npub)
+                        let npub = try? idBridge.getCurrentNostrIdentity()?.npub
+                        _ = VerificationService.shared.buildMyQRString(nickname: nickname, npub: npub)
                    }
-                    #if os(iOS)
+
                    appDelegate.chatViewModel = chatViewModel
-                    #elseif os(macOS)
-                    appDelegate.chatViewModel = chatViewModel
-                    #endif
+
                    // Initialize network activation policy; will start Tor/Nostr only when allowed
                    NetworkActivationService.shared.start()
+                    
+                    // Start presence service (will wait for Tor readiness)
+                    GeohashPresenceService.shared.start()
+
                    // Check for shared content
                    checkForSharedContent()
                }
@@ -185,6 +193,10 @@ final class AppDelegate: NSObject, UIApplicationDelegate {
    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey : Any]? = nil) -> Bool {
        return true
    }
+    
+    func applicationWillTerminate(_ application: UIApplication) {
+        chatViewModel?.applicationWillTerminate()
+    }
 }
 #endif

@@ -217,7 +229,7 @@ final class NotificationDelegate: NSObject, UNUserNotificationCenterDelegate {
            // Get peer ID from userInfo
            if let peerID = userInfo["peerID"] as? String {
                DispatchQueue.main.async {
-                    self.chatViewModel?.startPrivateChat(with: peerID)
+                    self.chatViewModel?.startPrivateChat(with: PeerID(str: peerID))
                }
            }
        }
@@ -242,10 +254,15 @@ final class NotificationDelegate: NSObject, UNUserNotificationCenterDelegate {
            // Get peer ID from userInfo
            if let peerID = userInfo["peerID"] as? String {
                // Don't show notification if the private chat is already open
-                if chatViewModel?.selectedPrivateChatPeer == peerID {
-                    completionHandler([])
-                    return
+                // Access main-actor-isolated property via Task
+                Task { @MainActor in
+                    if self.chatViewModel?.selectedPrivateChatPeer == PeerID(str: peerID) {
+                        completionHandler([])
+                    } else {
+                        completionHandler([.banner, .sound])
+                    }
                }
+                return
            }
        }
        // Suppress geohash activity notification if we're already in that geohash channel
@@ -263,8 +280,3 @@ final class NotificationDelegate: NSObject, UNUserNotificationCenterDelegate {
    }
 }

-extension String {
-    var nilIfEmpty: String? {
-        self.isEmpty ? nil : self
-    }
-}
@@ -0,0 +1,203 @@
+import Foundation
+import ImageIO
+import UniformTypeIdentifiers
+#if os(iOS)
+import UIKit
+#else
+import AppKit
+#endif
+
+enum ImageUtilsError: Error {
+    case invalidImage
+    case encodingFailed
+}
+
+enum ImageUtils {
+    private static let compressionQuality: CGFloat = 0.82
+    private static let targetImageBytes: Int = 45_000
+
+    static func processImage(at url: URL, maxDimension: CGFloat = 448) throws -> URL {
+        // Security H1: Check file size BEFORE reading into memory
+        let attrs = try FileManager.default.attributesOfItem(atPath: url.path)
+        guard let fileSize = attrs[.size] as? Int else {
+            throw ImageUtilsError.invalidImage
+        }
+        // Allow up to 10MB source images (will be scaled down)
+        guard fileSize <= 10 * 1024 * 1024 else {
+            throw ImageUtilsError.invalidImage
+        }
+
+        let data = try Data(contentsOf: url)
+        #if os(iOS)
+        guard let image = UIImage(data: data) else { throw ImageUtilsError.invalidImage }
+        return try processImage(image, maxDimension: maxDimension)
+        #else
+        guard let image = NSImage(data: data) else { throw ImageUtilsError.invalidImage }
+        return try processImage(image, maxDimension: maxDimension)
+        #endif
+    }
+
+    #if os(iOS)
+    static func processImage(_ image: UIImage, maxDimension: CGFloat = 448) throws -> URL {
+        return try autoreleasepool {
+            // Scale the image first
+            let scaled = scaledImage(image, maxDimension: maxDimension)
+
+            // Get CGImage from UIImage - this is the key to stripping metadata
+            guard let cgImage = scaled.cgImage else {
+                throw ImageUtilsError.encodingFailed
+            }
+
+            // Use CGImageDestination to encode without metadata (same as macOS)
+            var quality = compressionQuality
+            guard var jpegData = encodeJPEG(from: cgImage, quality: quality) else {
+                throw ImageUtilsError.encodingFailed
+            }
+
+            // Compress to target size
+            while jpegData.count > targetImageBytes && quality > 0.3 {
+                quality -= 0.1
+                autoreleasepool {
+                    if let next = encodeJPEG(from: cgImage, quality: quality) {
+                        jpegData = next
+                    }
+                }
+            }
+
+            let outputURL = try makeOutputURL()
+            try jpegData.write(to: outputURL, options: .atomic)
+            return outputURL
+        }
+    }
+
+    private static func scaledImage(_ image: UIImage, maxDimension: CGFloat) -> UIImage {
+        let size = image.size
+        let maxSide = max(size.width, size.height)
+        guard maxSide > maxDimension else { return image }
+        let scale = maxDimension / maxSide
+        let newSize = CGSize(width: size.width * scale, height: size.height * scale)
+
+        // Draw into a new context to get a clean CGImage without metadata
+        UIGraphicsBeginImageContextWithOptions(newSize, true, 1.0)
+        image.draw(in: CGRect(origin: .zero, size: newSize))
+        let rendered = UIGraphicsGetImageFromCurrentImageContext()
+        UIGraphicsEndImageContext()
+        return rendered ?? image
+    }
+
+    // Shared EXIF-stripping JPEG encoder for both iOS and macOS
+    private static func encodeJPEG(from cgImage: CGImage, quality: CGFloat) -> Data? {
+        guard let data = CFDataCreateMutable(nil, 0) else {
+            return nil
+        }
+        guard let destination = CGImageDestinationCreateWithData(data, UTType.jpeg.identifier as CFString, 1, nil) else {
+            return nil
+        }
+        // Security: Strip ALL metadata (EXIF, GPS, TIFF, IPTC, XMP)
+        // By only specifying compression quality and no metadata keys,
+        // we ensure a clean JPEG with no privacy-leaking information
+        let options: [CFString: Any] = [
+            kCGImageDestinationLossyCompressionQuality: quality
+        ]
+        CGImageDestinationAddImage(destination, cgImage, options as CFDictionary)
+        guard CGImageDestinationFinalize(destination) else {
+            return nil
+        }
+        return data as Data
+    }
+    #else
+    static func processImage(_ image: NSImage, maxDimension: CGFloat = 448) throws -> URL {
+        return try autoreleasepool {
+            let scaled = scaledImage(image, maxDimension: maxDimension)
+            guard let inputCG = scaled.cgImage(forProposedRect: nil, context: nil, hints: nil) else {
+                throw ImageUtilsError.encodingFailed
+            }
+            let width = inputCG.width
+            let height = inputCG.height
+            let colorSpace = CGColorSpace(name: CGColorSpace.sRGB) ?? CGColorSpaceCreateDeviceRGB()
+            guard let context = CGContext(
+                data: nil,
+                width: width,
+                height: height,
+                bitsPerComponent: 8,
+                bytesPerRow: 0,
+                space: colorSpace,
+                bitmapInfo: CGImageAlphaInfo.premultipliedLast.rawValue
+            ) else {
+                throw ImageUtilsError.encodingFailed
+            }
+            context.draw(inputCG, in: CGRect(x: 0, y: 0, width: width, height: height))
+            guard let cgImage = context.makeImage() else {
+                throw ImageUtilsError.encodingFailed
+            }
+            var quality = compressionQuality
+            guard var jpegData = encodeJPEG(from: cgImage, quality: quality) else {
+                throw ImageUtilsError.encodingFailed
+            }
+            while jpegData.count > targetImageBytes && quality > 0.3 {
+                quality -= 0.1
+                autoreleasepool {
+                    if let next = encodeJPEG(from: cgImage, quality: quality) {
+                        jpegData = next
+                    }
+                }
+            }
+            let outputURL = try makeOutputURL()
+            try jpegData.write(to: outputURL, options: .atomic)
+            return outputURL
+        }
+    }
+
+    private static func scaledImage(_ image: NSImage, maxDimension: CGFloat) -> NSImage {
+        let size = image.size
+        let maxSide = max(size.width, size.height)
+        guard maxSide > maxDimension else { return image }
+        let scale = maxDimension / maxSide
+        let newSize = NSSize(width: size.width * scale, height: size.height * scale)
+        let scaledImage = NSImage(size: newSize)
+        scaledImage.lockFocus()
+        image.draw(in: NSRect(origin: .zero, size: newSize),
+                   from: NSRect(origin: .zero, size: size),
+                   operation: .copy,
+                   fraction: 1.0)
+        scaledImage.unlockFocus()
+        return scaledImage
+    }
+
+    // Shared EXIF-stripping JPEG encoder for both iOS and macOS
+    private static func encodeJPEG(from cgImage: CGImage, quality: CGFloat) -> Data? {
+        guard let data = CFDataCreateMutable(nil, 0) else {
+            return nil
+        }
+        guard let destination = CGImageDestinationCreateWithData(data, UTType.jpeg.identifier as CFString, 1, nil) else {
+            return nil
+        }
+        // Security: Strip ALL metadata (EXIF, GPS, TIFF, IPTC, XMP)
+        // By only specifying compression quality and no metadata keys,
+        // we ensure a clean JPEG with no privacy-leaking information
+        let options: [CFString: Any] = [
+            kCGImageDestinationLossyCompressionQuality: quality
+        ]
+        CGImageDestinationAddImage(destination, cgImage, options as CFDictionary)
+        guard CGImageDestinationFinalize(destination) else {
+            return nil
+        }
+        return data as Data
+    }
+    #endif
+
+    private static func makeOutputURL() throws -> URL {
+        let formatter = DateFormatter()
+        formatter.dateFormat = "yyyyMMdd_HHmmss"
+        let fileName = "img_\(formatter.string(from: Date())).jpg"
+
+        let directory = try applicationFilesDirectory().appendingPathComponent("images/outgoing", isDirectory: true)
+        try FileManager.default.createDirectory(at: directory, withIntermediateDirectories: true, attributes: nil)
+        return directory.appendingPathComponent(fileName)
+    }
+
+    private static func applicationFilesDirectory() throws -> URL {
+        let base = try FileManager.default.url(for: .applicationSupportDirectory, in: .userDomainMask, appropriateFor: nil, create: true)
+        return base.appendingPathComponent("files", isDirectory: true)
+    }
+}
@@ -0,0 +1,205 @@
+import Foundation
+import AVFoundation
+import BitLogger
+
+/// Controls playback for a single voice note and coordinates exclusive playback across the app.
+final class VoiceNotePlaybackController: NSObject, ObservableObject, AVAudioPlayerDelegate {
+    @Published private(set) var isPlaying: Bool = false
+    @Published private(set) var currentTime: TimeInterval = 0
+    @Published private(set) var duration: TimeInterval = 0
+    @Published private(set) var progress: Double = 0
+
+    /// rounded so 4.9s shows "00:05"
+    var roundedDuration: Int {
+        guard duration.isFinite else { return 0 }
+        return Int(duration.rounded())
+    }
+
+    /// ceil so "00:01" stays visible until playback ends, capped to rounded duration
+    var remainingSeconds: Int {
+        let remaining = max(0, duration - currentTime)
+        return min(roundedDuration, Int(ceil(remaining)))
+    }
+
+    private var player: AVAudioPlayer?
+    private var timer: Timer?
+    private var url: URL
+
+    init(url: URL) {
+        self.url = url
+        super.init()
+        // Don't load anything eagerly - wait until user interaction or view is fully displayed
+    }
+
+    func loadDuration() {
+        guard duration == 0 else { return }
+
+        DispatchQueue.global(qos: .utility).async { [weak self] in
+            guard let self = self else { return }
+            do {
+                let player = try AVAudioPlayer(contentsOf: self.url)
+                let loadedDuration = player.duration
+                DispatchQueue.main.async { [weak self] in
+                    guard let self = self, self.duration == 0 else { return }
+                    self.duration = loadedDuration
+                }
+            } catch {
+                SecureLogger.error("Failed to load audio duration: \(error)", category: .session)
+            }
+        }
+    }
+
+    deinit {
+        timer?.invalidate()
+    }
+
+    func replaceURL(_ url: URL) {
+        guard url != self.url else { return }
+        stop()
+        self.url = url
+        player = nil
+        duration = 0
+        // Duration will be loaded on demand when needed
+    }
+
+    func togglePlayback() {
+        isPlaying ? pause() : play()
+    }
+
+    func play() {
+        guard ensurePlayerReady() else { return }
+        VoiceNotePlaybackCoordinator.shared.activate(self)
+        player?.play()
+        startTimer()
+        updateProgress()
+        isPlaying = true
+    }
+
+    func pause() {
+        player?.pause()
+        stopTimer()
+        updateProgress()
+        isPlaying = false
+    }
+
+    func stop() {
+        player?.stop()
+        player?.currentTime = 0
+        stopTimer()
+        updateProgress()
+        isPlaying = false
+        VoiceNotePlaybackCoordinator.shared.deactivate(self)
+    }
+
+    func seek(to fraction: Double) {
+        guard ensurePlayerReady() else { return }
+        let clamped = max(0, min(1, fraction))
+        if let player = player {
+            player.currentTime = clamped * player.duration
+            if isPlaying {
+                player.play()
+            }
+            updateProgress()
+        }
+    }
+
+    // MARK: - AVAudioPlayerDelegate
+
+    func audioPlayerDidFinishPlaying(_ player: AVAudioPlayer, successfully flag: Bool) {
+        // Delegate callback may be on background thread - ensure main thread for UI updates
+        DispatchQueue.main.async { [weak self] in
+            guard let self = self else { return }
+            self.stopTimer()
+            self.updateProgress()
+            self.isPlaying = false
+            VoiceNotePlaybackCoordinator.shared.deactivate(self)
+        }
+    }
+
+    // MARK: - Private Helpers
+
+    private func preparePlayer(for url: URL) {
+        // Prepare player synchronously (only called when playback is requested)
+        do {
+            let player = try AVAudioPlayer(contentsOf: url)
+            player.delegate = self
+            player.prepareToPlay()
+            self.player = player
+            duration = player.duration
+            currentTime = player.currentTime
+            progress = duration > 0 ? currentTime / duration : 0
+        } catch {
+            SecureLogger.error("Voice note playback failed for \(url.lastPathComponent): \(error)", category: .session)
+            player = nil
+            duration = 0
+            currentTime = 0
+            progress = 0
+        }
+    }
+
+    private func ensurePlayerReady() -> Bool {
+        if player == nil {
+            preparePlayer(for: url)
+        }
+        #if os(iOS)
+        let session = AVAudioSession.sharedInstance()
+        do {
+            try session.setCategory(.playback, mode: .spokenAudio, options: [.mixWithOthers])
+            try session.setActive(true, options: [])
+        } catch {
+            SecureLogger.error("Failed to activate audio session: \(error)", category: .session)
+        }
+        #endif
+        return player != nil
+    }
+
+    private func startTimer() {
+        if timer != nil { return }
+        timer = Timer.scheduledTimer(withTimeInterval: 0.05, repeats: true) { [weak self] _ in
+            self?.updateProgress()
+        }
+        if let timer = timer {
+            RunLoop.main.add(timer, forMode: .common)
+        }
+    }
+
+    private func stopTimer() {
+        timer?.invalidate()
+        timer = nil
+    }
+
+    private func updateProgress() {
+        guard let player = player else {
+            currentTime = 0
+            duration = 0
+            progress = 0
+            return
+        }
+        currentTime = player.currentTime
+        duration = player.duration
+        progress = duration > 0 ? currentTime / duration : 0
+    }
+}
+
+/// Ensures only one voice note plays at a time.
+final class VoiceNotePlaybackCoordinator {
+    static let shared = VoiceNotePlaybackCoordinator()
+
+    private weak var activeController: VoiceNotePlaybackController?
+
+    private init() {}
+
+    func activate(_ controller: VoiceNotePlaybackController) {
+        if activeController === controller {
+            return
+        }
+        activeController?.pause()
+        activeController = controller
+    }
+
+    func deactivate(_ controller: VoiceNotePlaybackController) {
+        if activeController === controller {
+            activeController = nil
+        }
+    }
+}
@@ -0,0 +1,155 @@
+import Foundation
+import AVFoundation
+
+/// Manages audio capture for mesh voice notes with predictable encoding settings.
+actor VoiceRecorder {
+    enum RecorderError: Error {
+        case microphoneAccessDenied
+        case recorderInitializationFailed
+        case recordingInProgress
+    }
+
+    static let shared = VoiceRecorder()
+
+    private let paddingInterval: TimeInterval = 0.5
+    private let maxRecordingDuration: TimeInterval = 120
+    static let minRecordingDuration: TimeInterval = 1
+
+    private var recorder: AVAudioRecorder?
+    private var currentURL: URL?
+
+    // MARK: - Permissions
+
+    nonisolated
+    func requestPermission() async -> Bool {
+        #if os(iOS)
+        return await withCheckedContinuation { continuation in
+            AVAudioSession.sharedInstance().requestRecordPermission { granted in
+                continuation.resume(returning: granted)
+            }
+        }
+        #elseif os(macOS)
+        return await withCheckedContinuation { continuation in
+            AVCaptureDevice.requestAccess(for: .audio) { granted in
+                continuation.resume(returning: granted)
+            }
+        }
+        #else
+        return true
+        #endif
+    }
+
+    // MARK: - Recording Lifecycle
+
+    @discardableResult
+    func startRecording() throws -> URL {
+        if recorder?.isRecording == true {
+            throw RecorderError.recordingInProgress
+        }
+
+        #if os(iOS)
+        let session = AVAudioSession.sharedInstance()
+        guard session.recordPermission == .granted else {
+            throw RecorderError.microphoneAccessDenied
+        }
+        #if targetEnvironment(simulator)
+        // allowBluetoothHFP is not available on iOS Simulator
+        try session.setCategory(
+            .playAndRecord,
+            mode: .default,
+            options: [.defaultToSpeaker, .allowBluetoothA2DP]
+        )
+        #else
+        try session.setCategory(
+            .playAndRecord,
+            mode: .default,
+            options: [.defaultToSpeaker, .allowBluetoothA2DP, .allowBluetoothHFP]
+        )
+        #endif
+        try session.setActive(true, options: .notifyOthersOnDeactivation)
+        #endif
+        #if os(macOS)
+        guard AVCaptureDevice.authorizationStatus(for: .audio) == .authorized else {
+            throw RecorderError.microphoneAccessDenied
+        }
+        #endif
+
+        let outputURL = try makeOutputURL()
+        let settings: [String: Any] = [
+            AVFormatIDKey: kAudioFormatMPEG4AAC,
+            AVSampleRateKey: 16_000,
+            AVNumberOfChannelsKey: 1,
+            AVEncoderBitRateKey: 16_000
+        ]
+
+        let audioRecorder = try AVAudioRecorder(url: outputURL, settings: settings)
+        audioRecorder.isMeteringEnabled = true
+        audioRecorder.prepareToRecord()
+        audioRecorder.record(forDuration: maxRecordingDuration)
+
+        recorder = audioRecorder
+        currentURL = outputURL
+        return outputURL
+    }
+
+    func stopRecording() async -> URL? {
+        guard let recorder, recorder.isRecording else {
+            return currentURL
+        }
+
+        let sessionURL = currentURL
+
+        try? await Task.sleep(nanoseconds: UInt64(paddingInterval * 1_000_000_000))
+
+        recorder.stop()
+
+        // A new session may have started during the sleep — don't touch its state
+        if self.recorder === recorder {
+            cleanupSession()
+            self.recorder = nil
+            currentURL = nil
+        }
+
+        return sessionURL
+    }
+
+    func cancelRecording() {
+        if let recorder, recorder.isRecording {
+            recorder.stop()
+        }
+        cleanupSession()
+        if let currentURL {
+            try? FileManager.default.removeItem(at: currentURL)
+        }
+        recorder = nil
+        currentURL = nil
+    }
+
+    // MARK: - Helpers
+
+    private func makeOutputURL() throws -> URL {
+        let formatter = DateFormatter()
+        formatter.dateFormat = "yyyyMMdd_HHmmss"
+        let fileName = "voice_\(formatter.string(from: Date())).m4a"
+
+        let baseDirectory = try applicationFilesDirectory().appendingPathComponent("voicenotes/outgoing", isDirectory: true)
+        try FileManager.default.createDirectory(at: baseDirectory, withIntermediateDirectories: true, attributes: nil)
+        return baseDirectory.appendingPathComponent(fileName)
+    }
+
+    private func applicationFilesDirectory() throws -> URL {
+        #if os(iOS)
+        return try FileManager.default.url(for: .applicationSupportDirectory, in: .userDomainMask, appropriateFor: nil, create: true)
+            .appendingPathComponent("files", isDirectory: true)
+        #else
+        let base = try FileManager.default.url(for: .applicationSupportDirectory, in: .userDomainMask, appropriateFor: nil, create: true)
+        return base.appendingPathComponent("files", isDirectory: true)
+        #endif
+    }
+
+    private func cleanupSession() {
+        #if os(iOS)
+        try? AVAudioSession.sharedInstance().setActive(false, options: .notifyOthersOnDeactivation)
+        #endif
+    }
+}
@@ -0,0 +1,113 @@
+import AVFoundation
+import Foundation
+import BitLogger
+
+/// Generates and caches downsampled waveforms for audio files so UI rendering is cheap.
+final class WaveformCache {
+    static let shared = WaveformCache()
+
+    private let queue = DispatchQueue(label: "com.bitchat.waveform-cache", attributes: .concurrent)
+    private var cache: [URL: (waveform: [Float], lastAccess: Date)] = [:]
+    private let maxCacheSize = 20  // Limit cache to prevent unbounded memory growth
+
+    private init() {}
+
+    func cachedWaveform(for url: URL) -> [Float]? {
+        queue.sync {
+            guard let entry = cache[url] else { return nil }
+            return entry.waveform
+        }
+    }
+
+    func waveform(for url: URL, bins: Int = 120, completion: @escaping ([Float]) -> Void) {
+        queue.async { [weak self] in
+            guard let self = self else { return }
+
+            // Check cache (read-only, no update needed on cache hit for performance)
+            if let entry = self.cache[url] {
+                DispatchQueue.main.async { completion(entry.waveform) }
+                return
+            }
+
+            guard let computed = self.computeWaveform(url: url, bins: bins) else {
+                DispatchQueue.main.async { completion([]) }
+                return
+            }
+
+            self.queue.async(flags: .barrier) { [weak self] in
+                guard let self = self else { return }
+
+                // Evict oldest entry if cache is full
+                if self.cache.count >= self.maxCacheSize {
+                    if let oldest = self.cache.min(by: { $0.value.lastAccess < $1.value.lastAccess }) {
+                        self.cache.removeValue(forKey: oldest.key)
+                    }
+                }
+
+                self.cache[url] = (computed, Date())
+            }
+            DispatchQueue.main.async { completion(computed) }
+        }
+    }
+
+    func purge(url: URL) {
+        queue.async(flags: .barrier) { [weak self] in
+            self?.cache.removeValue(forKey: url)
+        }
+    }
+
+    func purgeAll() {
+        queue.async(flags: .barrier) { [weak self] in
+            self?.cache.removeAll()
+        }
+    }
+
+    private func computeWaveform(url: URL, bins: Int) -> [Float]? {
+        guard bins > 0 else { return nil }
+        // Use autoreleasepool to manage memory from audio buffer allocations
+        return autoreleasepool {
+            do {
+                let audioFile = try AVAudioFile(forReading: url)
+                let length = Int(audioFile.length)
+                guard length > 0 else { return nil }
+
+                guard let buffer = AVAudioPCMBuffer(pcmFormat: audioFile.processingFormat, frameCapacity: AVAudioFrameCount(length)) else {
+                    return nil
+                }
+                try audioFile.read(into: buffer, frameCount: AVAudioFrameCount(length))
+                guard let channelData = buffer.floatChannelData else { return nil }
+
+                let channelCount = Int(audioFile.processingFormat.channelCount)
+                let frameLength = Int(buffer.frameLength)
+                let samplesPerBin = max(1, frameLength / bins)
+
+                var magnitudes: [Float] = Array(repeating: 0, count: bins)
+                for bin in 0..<bins {
+                    let start = bin * samplesPerBin
+                    let end = min(frameLength, start + samplesPerBin)
+                    if start >= end { break }
+
+                    var sum: Float = 0
+                    var sampleCount = 0
+                    for frame in start..<end {
+                        var sampleValue: Float = 0
+                        for channel in 0..<channelCount {
+                            sampleValue += fabsf(channelData[channel][frame])
+                        }
+                        sum += sampleValue / Float(channelCount)
+                        sampleCount += 1
+                    }
+                    magnitudes[bin] = sampleCount > 0 ? sum / Float(sampleCount) : 0
+                }
+
+                if let maxMagnitude = magnitudes.max(), maxMagnitude > 0 {
+                    magnitudes = magnitudes.map { min($0 / maxMagnitude, 1.0) }
+                }
+                return magnitudes
+            } catch {
+                SecureLogger.error("Waveform extraction failed for \(url.lastPathComponent): \(error)", category: .session)
+                return nil
+            }
+        }
+    }
+}
@@ -81,6 +81,7 @@
 ///

 import Foundation
+import BitFoundation

 // MARK: - Three-Layer Identity Model

@@ -91,6 +91,7 @@
 ///

 import BitLogger
+import BitFoundation
 import Foundation
 import CryptoKit

@@ -331,16 +332,15 @@ final class SecureIdentityStateManager: SecureIdentityStateManagerProtocol {
    
    func updateSocialIdentity(_ identity: SocialIdentity) {
        queue.async(flags: .barrier) {
+            let previousClaimedNickname = self.cache.socialIdentities[identity.fingerprint]?.claimedNickname
            self.cache.socialIdentities[identity.fingerprint] = identity
            
            // Update nickname index
-            if let existingIdentity = self.cache.socialIdentities[identity.fingerprint] {
-                // Remove old nickname from index if changed
-                if existingIdentity.claimedNickname != identity.claimedNickname {
-                    self.cache.nicknameIndex[existingIdentity.claimedNickname]?.remove(identity.fingerprint)
-                    if self.cache.nicknameIndex[existingIdentity.claimedNickname]?.isEmpty == true {
-                        self.cache.nicknameIndex.removeValue(forKey: existingIdentity.claimedNickname)
-                    }
+            if let previousClaimedNickname,
+               previousClaimedNickname != identity.claimedNickname {
+                self.cache.nicknameIndex[previousClaimedNickname]?.remove(identity.fingerprint)
+                if self.cache.nicknameIndex[previousClaimedNickname]?.isEmpty == true {
+                    self.cache.nicknameIndex.removeValue(forKey: previousClaimedNickname)
                }
            }
            
@@ -532,4 +532,16 @@ final class SecureIdentityStateManager: SecureIdentityStateManagerProtocol {
            return cache.verifiedFingerprints
        }
    }
+
+    var debugNicknameIndex: [String: Set<String>] {
+        queue.sync { cache.nicknameIndex }
+    }
+
+    func debugEphemeralSession(for peerID: PeerID) -> EphemeralIdentity? {
+        queue.sync { ephemeralSessions[peerID] }
+    }
+
+    func debugLastInteraction(for fingerprint: String) -> Date? {
+        queue.sync { cache.lastInteractions[fingerprint] }
+    }
 }
@@ -2,6 +2,8 @@
 <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
 <plist version="1.0">
 <dict>
+	<key>AppGroupID</key>
+	<string>$(APP_GROUP_ID)</string>
 	<key>CFBundleDevelopmentRegion</key>
 	<string>$(DEVELOPMENT_LANGUAGE)</string>
 	<key>CFBundleDisplayName</key>
@@ -39,6 +41,10 @@
 	<string>bitchat uses the camera to scan QR codes to verify peers.</string>
 	<key>NSLocationWhenInUseUsageDescription</key>
 	<string>bitchat uses your approximate location to compute local geohash channels for optional public chats. Exact GPS is never shared.</string>
+	<key>NSMicrophoneUsageDescription</key>
+	<string>bitchat uses the microphone to record voice notes that relay across the mesh.</string>
+	<key>NSPhotoLibraryUsageDescription</key>
+	<string>bitchat lets you pick images from your photo library to share with nearby peers.</string>
 	<key>UIBackgroundModes</key>
 	<array>
 		<string>bluetooth-central</string>
@@ -0,0 +1,68 @@
+//
+// BitchatMessage+Media.swift
+// bitchat
+//
+// This is free and unencumbered software released into the public domain.
+// For more information, see <https://unlicense.org>
+//
+
+import Foundation
+
+extension BitchatMessage {
+    enum Media {
+        case voice(URL)
+        case image(URL)
+
+        var url: URL {
+            switch self {
+            case .voice(let url), .image(let url):
+                return url
+            }
+        }
+    }
+
+    // Cache the directory lookup to avoid repeated FileManager calls during view rendering
+    private struct Cache {
+        let filesDir: URL?
+
+        static let shared = Cache()
+        private init() {
+            do {
+                let base = try FileManager.default.url(for: .applicationSupportDirectory, in: .userDomainMask, appropriateFor: nil, create: true)
+                let filesDir = base.appendingPathComponent("files", isDirectory: true)
+                try FileManager.default.createDirectory(at: filesDir, withIntermediateDirectories: true, attributes: nil)
+                self.filesDir = filesDir
+            } catch {
+                filesDir = nil
+            }
+        }
+    }
+
+    func mediaAttachment(for nickname: String) -> Media? {
+        guard let baseDirectory = Cache.shared.filesDir else { return nil }
+
+        func url(for category: MimeType.Category) -> URL? {
+            guard content.hasPrefix(category.messagePrefix),
+                  let filename = String(content.dropFirst(category.messagePrefix.count)).trimmedOrNilIfEmpty
+            else {
+                return nil
+            }
+
+            // Check outgoing first for sent messages, incoming for received
+            let subdir = sender == nickname ? "\(category.mediaDir)/outgoing" : "\(category.mediaDir)/incoming"
+
+            // Construct URL directly without fileExists check (avoids blocking disk I/O in view body)
+            // Files are checked during playback/display, so missing files fail gracefully
+            let directory = baseDirectory.appendingPathComponent(subdir, isDirectory: true)
+            return directory.appendingPathComponent(filename)
+        }
+
+        if let url = url(for: .audio) {
+            return .voice(url)
+        }
+        if let url = url(for: .image) {
+            return .image(url)
+        }
+        return nil
+    }
+}
@@ -7,6 +7,7 @@
 //

 import Foundation
+import BitFoundation

 /// Represents a user-visible message in the BitChat system.
 /// Handles both broadcast messages and private encrypted messages,
@@ -338,7 +339,7 @@ extension BitchatMessage {
 extension Array where Element == BitchatMessage {
    /// Filters out empty ones and deduplicate by ID while preserving order (from oldest to newest)
    func cleanedAndDeduped() -> [Element] {
-        let arr = filter { $0.content.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty == false }
+        let arr = filter { $0.content.trimmed.isEmpty == false }
        guard arr.count > 1 else {
            return arr
        }
@@ -7,6 +7,7 @@
 //

 import Foundation
+import BitFoundation

 /// The core packet structure for all BitChat protocol messages.
 /// Encapsulates all data needed for routing through the mesh network,
@@ -21,9 +22,11 @@ struct BitchatPacket: Codable {
    let payload: Data
    var signature: Data?
    var ttl: UInt8
+    var route: [Data]?
+    var isRSR: Bool
    
-    init(type: UInt8, senderID: Data, recipientID: Data?, timestamp: UInt64, payload: Data, signature: Data?, ttl: UInt8) {
-        self.version = 1
+    init(type: UInt8, senderID: Data, recipientID: Data?, timestamp: UInt64, payload: Data, signature: Data?, ttl: UInt8, version: UInt8 = 1, route: [Data]? = nil, isRSR: Bool = false) {
+        self.version = version
        self.type = type
        self.senderID = senderID
        self.recipientID = recipientID
@@ -31,10 +34,12 @@ struct BitchatPacket: Codable {
        self.payload = payload
        self.signature = signature
        self.ttl = ttl
+        self.route = route
+        self.isRSR = isRSR
    }
    
    // Convenience initializer for new binary format
-    init(type: UInt8, ttl: UInt8, senderID: PeerID, payload: Data) {
+    init(type: UInt8, ttl: UInt8, senderID: PeerID, payload: Data, isRSR: Bool = false) {
        self.version = 1
        self.type = type
        // Convert hex string peer ID to binary data (8 bytes)
@@ -53,6 +58,8 @@ struct BitchatPacket: Codable {
        self.payload = payload
        self.signature = nil
        self.ttl = ttl
+        self.route = nil
+        self.isRSR = isRSR
    }
    
    var data: Data? {
@@ -80,7 +87,10 @@ struct BitchatPacket: Codable {
            timestamp: timestamp,
            payload: payload,
            signature: nil, // Remove signature for signing
-            ttl: 0 // Use fixed TTL=0 for signing to ensure relay compatibility
+            ttl: 0, // Use fixed TTL=0 for signing to ensure relay compatibility
+            version: version,
+            route: route,
+            isRSR: false // RSR flag is mutable and not part of the signature
        )
        return BinaryProtocol.encode(unsignedPacket)
    }
@@ -1,5 +1,6 @@
 import Foundation
 import CoreBluetooth
+import BitFoundation

 /// Represents a peer in the BitChat network with all associated metadata
 struct BitchatPeer: Equatable {
@@ -0,0 +1,58 @@
+//
+// CommandsInfo.swift
+// bitchat
+//
+// This is free and unencumbered software released into the public domain.
+// For more information, see <https://unlicense.org>
+//
+
+import Foundation
+
+// MARK: - CommandInfo Enum
+
+enum CommandInfo: String, Identifiable {
+    case block
+    case clear
+    case hug
+    case message = "dm"
+    case slap
+    case unblock
+    case who
+    case favorite
+    case unfavorite
+    
+    var id: String { rawValue }
+    
+    var alias: String { "/" + rawValue }
+    
+    var placeholder: String? {
+        switch self {
+        case .block, .hug, .message, .slap, .unblock, .favorite, .unfavorite:
+            return "<" + String(localized: "content.input.nickname_placeholder") + ">"
+        case .clear, .who:
+            return nil
+        }
+    }
+    
+    var description: String {
+        switch self {
+        case .block:        String(localized: "content.commands.block")
+        case .clear:        String(localized: "content.commands.clear")
+        case .hug:          String(localized: "content.commands.hug")
+        case .message:      String(localized: "content.commands.message")
+        case .slap:         String(localized: "content.commands.slap")
+        case .unblock:      String(localized: "content.commands.unblock")
+        case .who:          String(localized: "content.commands.who")
+        case .favorite:     String(localized: "content.commands.favorite")
+        case .unfavorite:   String(localized: "content.commands.unfavorite")
+        }
+    }
+    
+    static func all(isGeoPublic: Bool, isGeoDM: Bool) -> [CommandInfo] {
+        let baseCommands: [CommandInfo] = [.block, .unblock, .clear, .hug, .message, .slap, .who]
+        if isGeoPublic || isGeoDM {
+            return baseCommands + [.favorite, .unfavorite]
+        }
+        return baseCommands
+    }
+}
@@ -7,15 +7,16 @@
 //

 import Foundation
+import BitFoundation

 struct ReadReceipt: Codable {
    let originalMessageID: String
    let receiptID: String
-    var readerID: String  // Who read it
+    var readerID: PeerID  // Who read it
    let readerNickname: String
    let timestamp: Date
    
-    init(originalMessageID: String, readerID: String, readerNickname: String) {
+    init(originalMessageID: String, readerID: PeerID, readerNickname: String) {
        self.originalMessageID = originalMessageID
        self.receiptID = UUID().uuidString
        self.readerID = readerID
@@ -24,7 +25,7 @@ struct ReadReceipt: Codable {
    }
    
    // For binary decoding
-    private init(originalMessageID: String, receiptID: String, readerID: String, readerNickname: String, timestamp: Date) {
+    private init(originalMessageID: String, receiptID: String, readerID: PeerID, readerNickname: String, timestamp: Date) {
        self.originalMessageID = originalMessageID
        self.receiptID = receiptID
        self.readerID = readerID
@@ -48,7 +49,7 @@ struct ReadReceipt: Codable {
        data.appendUUID(receiptID)
        // ReaderID as 8-byte hex string
        var readerData = Data()
-        var tempID = readerID
+        var tempID = readerID.id
        while tempID.count >= 2 && readerData.count < 8 {
            let hexByte = String(tempID.prefix(2))
            if let byte = UInt8(hexByte, radix: 16) {
@@ -78,8 +79,8 @@ struct ReadReceipt: Codable {
              let receiptID = dataCopy.readUUID(at: &offset) else { return nil }
        
        guard let readerIDData = dataCopy.readFixedBytes(at: &offset, count: 8) else { return nil }
-        let readerID = readerIDData.hexEncodedString()
-        guard PeerID(str: readerID).isValid else { return nil }
+        let readerID = PeerID(hexData: readerIDData)
+        guard readerID.isValid else { return nil }
        
        guard let timestamp = dataCopy.readDate(at: &offset),
              InputValidator.validateTimestamp(timestamp),
@@ -8,6 +8,18 @@ struct RequestSyncPacket {
    let p: Int
    let m: UInt32
    let data: Data
+    let types: SyncTypeFlags?
+    let sinceTimestamp: UInt64?
+    let fragmentIdFilter: String?
+
+    init(p: Int, m: UInt32, data: Data, types: SyncTypeFlags? = nil, sinceTimestamp: UInt64? = nil, fragmentIdFilter: String? = nil) {
+        self.p = p
+        self.m = m
+        self.data = data
+        self.types = types
+        self.sinceTimestamp = sinceTimestamp
+        self.fragmentIdFilter = fragmentIdFilter
+    }

    func encode() -> Data {
        var out = Data()
@@ -25,14 +37,27 @@ struct RequestSyncPacket {
        putTLV(0x02, withUnsafeBytes(of: &mBE) { Data($0) })
        // data
        putTLV(0x03, data)
+        if let typesData = types?.toData() {
+            putTLV(0x04, typesData)
+        }
+        if let ts = sinceTimestamp {
+            var tsBE = ts.bigEndian
+            putTLV(0x05, withUnsafeBytes(of: &tsBE) { Data($0) })
+        }
+        if let fid = fragmentIdFilter, let fidData = fid.data(using: .utf8) {
+            putTLV(0x06, fidData)
+        }
        return out
    }
-
+    
    static func decode(from data: Data, maxAcceptBytes: Int = 1024) -> RequestSyncPacket? {
        var off = 0
        var p: Int? = nil
        var m: UInt32? = nil
        var payload: Data? = nil
+        var types: SyncTypeFlags? = nil
+        var sinceTimestamp: UInt64? = nil
+        var fragmentIdFilter: String? = nil

        while off + 3 <= data.count {
            let t = Int(data[off]); off += 1
@@ -52,12 +77,26 @@ struct RequestSyncPacket {
            case 0x03:
                if v.count > maxAcceptBytes { return nil }
                payload = v
+            case 0x04:
+                if let decoded = SyncTypeFlags.decode(v) {
+                    types = decoded
+                }
+            case 0x05:
+                if v.count == 8 {
+                    var ts: UInt64 = 0
+                    for b in v { ts = (ts << 8) | UInt64(b) }
+                    sinceTimestamp = ts
+                }
+            case 0x06:
+                if let fid = String(data: v, encoding: .utf8) {
+                    fragmentIdFilter = fid
+                }
            default:
                break // forward compatible; ignore unknown TLVs
            }
        }

        guard let pp = p, let mm = m, let dd = payload, pp >= 1, mm > 0 else { return nil }
-        return RequestSyncPacket(p: pp, m: mm, data: dd)
+        return RequestSyncPacket(p: pp, m: mm, data: dd, types: types, sinceTimestamp: sinceTimestamp, fragmentIdFilter: fragmentIdFilter)
    }
 }
@@ -165,19 +165,23 @@ final class NoiseCipherState {
    // MARK: - Sliding Window Replay Protection
    
    /// Check if nonce is valid for replay protection
+    /// BCH-01-010: Use safe arithmetic to prevent integer overflow
    private func isValidNonce(_ receivedNonce: UInt64) -> Bool {
-        if receivedNonce + UInt64(Self.REPLAY_WINDOW_SIZE) <= highestReceivedNonce {
+        // Safe overflow check: instead of (receivedNonce + WINDOW_SIZE <= highest)
+        // use (highest >= WINDOW_SIZE && receivedNonce <= highest - WINDOW_SIZE)
+        let windowSize = UInt64(Self.REPLAY_WINDOW_SIZE)
+        if highestReceivedNonce >= windowSize && receivedNonce <= highestReceivedNonce - windowSize {
            return false  // Too old, outside window
        }
-        
+
        if receivedNonce > highestReceivedNonce {
            return true  // Always accept newer nonces
        }
-        
+
        let offset = Int(highestReceivedNonce - receivedNonce)
        let byteIndex = offset / 8
        let bitIndex = offset % 8
-        
+
        return (replayWindow[byteIndex] & (1 << bitIndex)) == 0  // Not yet seen
    }
    
@@ -222,7 +226,7 @@ final class NoiseCipherState {
        guard combinedPayload.count >= Self.NONCE_SIZE_BYTES else {
            return nil
        }
-
+        
        // Extract 4-byte nonce (big-endian)
        let nonceData = combinedPayload.prefix(Self.NONCE_SIZE_BYTES)
        let extractedNonce = nonceData.withUnsafeBytes { (bytes: UnsafeRawBufferPointer) -> UInt64 in
@@ -233,18 +237,18 @@ final class NoiseCipherState {
            }
            return result
        }
-
+        
        // Extract ciphertext (remaining bytes)
        let ciphertext = combinedPayload.dropFirst(Self.NONCE_SIZE_BYTES)
-
+        
        return (nonce: extractedNonce, ciphertext: Data(ciphertext))
    }
-
+    
    /// Convert nonce to 4-byte array (big-endian)
    private func nonceToBytes(_ nonce: UInt64) -> Data {
        var bytes = Data(count: Self.NONCE_SIZE_BYTES)
        withUnsafeBytes(of: nonce.bigEndian) { ptr in
-            // Copy only the last 4 bytes from the 8-byte UInt64 
+            // Copy only the last 4 bytes from the 8-byte UInt64
            let sourceBytes = ptr.bindMemory(to: UInt8.self)
            bytes.replaceSubrange(0..<Self.NONCE_SIZE_BYTES, with: sourceBytes.suffix(Self.NONCE_SIZE_BYTES))
        }
@@ -273,7 +277,7 @@ final class NoiseCipherState {
        let sealedBox = try ChaChaPoly.seal(plaintext, using: key, nonce: ChaChaPoly.Nonce(data: nonceData), authenticating: associatedData)
        // increment local nonce
        nonce += 1
-               
+        
        // Create combined payload: <nonce><ciphertext>
        let combinedPayload: Data
        if (useExtractedNonce) {
@@ -287,7 +291,7 @@ final class NoiseCipherState {
        if currentNonce > Self.HIGH_NONCE_WARNING_THRESHOLD {
            SecureLogger.warning("High nonce value detected: \(currentNonce) - consider rekeying", category: .encryption)
        }
-                
+        
        return combinedPayload
    }
    
@@ -316,7 +320,7 @@ final class NoiseCipherState {
                SecureLogger.debug("Replay attack detected: nonce \(extractedNonce) rejected")
                throw NoiseError.replayDetected
            }
-
+            
            // Split ciphertext and tag
            encryptedData = actualCiphertext.prefix(actualCiphertext.count - 16)
            tag = actualCiphertext.suffix(16)
@@ -347,16 +351,20 @@ final class NoiseCipherState {
        
        do {
            let plaintext = try ChaChaPoly.open(sealedBox, using: key, authenticating: associatedData)
-            
+
+            // BCH-01-010: Atomic nonce state update
+            // Both replay window marking and nonce increment must complete together
+            // to prevent state desynchronization. We perform both after successful
+            // decryption only, ensuring state consistency on any failure path.
            if useExtractedNonce {
-                // Mark nonce as seen after successful decryption
                markNonceAsSeen(decryptionNonce)
            }
            nonce += 1
+
            return plaintext
        } catch {
+            // Decryption failed - nonce state remains unchanged (atomic rollback)
            SecureLogger.debug("Decrypt failed: \(error) for nonce \(decryptionNonce)")
-            // Log authentication failures with nonce info
            SecureLogger.error("Decryption failed at nonce \(decryptionNonce)", category: .encryption)
            throw error
        }
@@ -376,6 +384,16 @@ final class NoiseCipherState {
            replayWindow[i] = 0
        }
    }
+
+    #if DEBUG
+    func setNonceForTesting(_ nonce: UInt64) {
+        self.nonce = nonce
+    }
+
+    func extractNonceFromCiphertextPayloadForTesting(_ combinedPayload: Data) throws -> (nonce: UInt64, ciphertext: Data)? {
+        try extractNonceFromCiphertextPayload(combinedPayload)
+    }
+    #endif
 }

 // MARK: - Symmetric State
@@ -451,17 +469,40 @@ final class NoiseSymmetricState {
        }
    }
    
-    func split() -> (NoiseCipherState, NoiseCipherState) {
+    func split(useExtractedNonce: Bool) -> (NoiseCipherState, NoiseCipherState) {
        let output = hkdf(chainingKey: chainingKey, inputKeyMaterial: Data(), numOutputs: 2)
        let tempKey1 = SymmetricKey(data: output[0])
        let tempKey2 = SymmetricKey(data: output[1])
-        
-        let c1 = NoiseCipherState(key: tempKey1, useExtractedNonce: true)
-        let c2 = NoiseCipherState(key: tempKey2, useExtractedNonce: true)
-        
+
+        let c1 = NoiseCipherState(key: tempKey1, useExtractedNonce: useExtractedNonce)
+        let c2 = NoiseCipherState(key: tempKey2, useExtractedNonce: useExtractedNonce)
+
+        // BCH-01-010: Clear symmetric state after split per Noise spec
+        // The chaining key and hash should not be retained after handshake completes
+        clearSensitiveData()
+
        return (c1, c2)
    }
-    
+
+    /// BCH-01-010: Securely clear sensitive cryptographic state
+    /// Called after split() to clear chaining key and hash per Noise spec
+    func clearSensitiveData() {
+        // Clear chaining key by overwriting with zeros
+        let chainingKeyCount = chainingKey.count
+        chainingKey = Data(repeating: 0, count: chainingKeyCount)
+
+        // Clear hash by overwriting with zeros
+        let hashCount = hash.count
+        hash = Data(repeating: 0, count: hashCount)
+
+        // Clear the internal cipher state
+        cipherState.clearSensitiveData()
+    }
+
+    deinit {
+        clearSensitiveData()
+    }
+
    // HKDF implementation
    private func hkdf(chainingKey: Data, inputKeyMaterial: Data, numOutputs: Int) -> [Data] {
        let tempKey = HMAC<SHA256>.authenticationCode(for: inputKeyMaterial, using: SymmetricKey(data: chainingKey))
@@ -507,16 +548,24 @@ final class NoiseHandshakeState {
    private var messagePatterns: [[NoiseMessagePattern]] = []
    private var currentPattern = 0
    
+    // Test support: predetermined ephemeral keys for test vectors
+    private var predeterminedEphemeralKey: Curve25519.KeyAgreement.PrivateKey?
+    private var prologueData: Data
+    
    init(
        role: NoiseRole,
        pattern: NoisePattern,
        keychain: KeychainManagerProtocol,
        localStaticKey: Curve25519.KeyAgreement.PrivateKey? = nil,
-        remoteStaticKey: Curve25519.KeyAgreement.PublicKey? = nil
+        remoteStaticKey: Curve25519.KeyAgreement.PublicKey? = nil,
+        prologue: Data = Data(),
+        predeterminedEphemeralKey: Curve25519.KeyAgreement.PrivateKey? = nil
    ) {
        self.role = role
        self.pattern = pattern
        self.keychain = keychain
+        self.prologueData = prologue
+        self.predeterminedEphemeralKey = predeterminedEphemeralKey
        
        // Initialize static keys
        if let localKey = localStaticKey {
@@ -537,8 +586,8 @@ final class NoiseHandshakeState {
    }
    
    private func mixPreMessageKeys() {
-        // Mix prologue (empty for XX pattern normally)
-        symmetricState.mixHash(Data()) // Empty prologue for XX pattern
+        // Mix prologue
+        symmetricState.mixHash(self.prologueData)
        // For XX pattern, no pre-message keys
        // For IK/NK patterns, we'd mix the responder's static key here
        switch pattern {
@@ -546,8 +595,9 @@ final class NoiseHandshakeState {
            break // No pre-message keys
        case .IK, .NK:
            if role == .initiator, let remoteStatic = remoteStaticPublic {
-                _ = symmetricState.getHandshakeHash()
                symmetricState.mixHash(remoteStatic.rawRepresentation)
+            } else if role == .responder, let localStatic = localStaticPublic {
+                symmetricState.mixHash(localStatic.rawRepresentation)
            }
        }
    }
@@ -556,15 +606,20 @@ final class NoiseHandshakeState {
        guard currentPattern < messagePatterns.count else {
            throw NoiseError.handshakeComplete
        }
-                
+        
        var messageBuffer = Data()
        let patterns = messagePatterns[currentPattern]
        
        for pattern in patterns {
            switch pattern {
            case .e:
-                // Generate ephemeral key
-                localEphemeralPrivate = Curve25519.KeyAgreement.PrivateKey()
+                // Generate ephemeral key (or use predetermined key for tests)
+                if let predetermined = predeterminedEphemeralKey {
+                    localEphemeralPrivate = predetermined
+                    predeterminedEphemeralKey = nil
+                } else {
+                    localEphemeralPrivate = Curve25519.KeyAgreement.PrivateKey()
+                }
                localEphemeralPublic = localEphemeralPrivate!.publicKey
                messageBuffer.append(localEphemeralPublic!.rawRepresentation)
                symmetricState.mixHash(localEphemeralPublic!.rawRepresentation)
@@ -597,14 +652,20 @@ final class NoiseHandshakeState {
                        throw NoiseError.missingKeys
                    }
                    let shared = try localEphemeral.sharedSecretFromKeyAgreement(with: remoteStatic)
-                    symmetricState.mixKey(shared.withUnsafeBytes { Data($0) })
+                    var sharedData = shared.withUnsafeBytes { Data($0) }
+                    symmetricState.mixKey(sharedData)
+                    // Clear sensitive shared secret
+                    keychain.secureClear(&sharedData)
                } else {
                    guard let localStatic = localStaticPrivate,
                          let remoteEphemeral = remoteEphemeralPublic else {
                        throw NoiseError.missingKeys
                    }
                    let shared = try localStatic.sharedSecretFromKeyAgreement(with: remoteEphemeral)
-                    symmetricState.mixKey(shared.withUnsafeBytes { Data($0) })
+                    var sharedData = shared.withUnsafeBytes { Data($0) }
+                    symmetricState.mixKey(sharedData)
+                    // Clear sensitive shared secret
+                    keychain.secureClear(&sharedData)
                }
                
            case .se:
@@ -615,14 +676,20 @@ final class NoiseHandshakeState {
                        throw NoiseError.missingKeys
                    }
                    let shared = try localStatic.sharedSecretFromKeyAgreement(with: remoteEphemeral)
-                    symmetricState.mixKey(shared.withUnsafeBytes { Data($0) })
+                    var sharedData = shared.withUnsafeBytes { Data($0) }
+                    symmetricState.mixKey(sharedData)
+                    // Clear sensitive shared secret
+                    keychain.secureClear(&sharedData)
                } else {
                    guard let localEphemeral = localEphemeralPrivate,
                          let remoteStatic = remoteStaticPublic else {
                        throw NoiseError.missingKeys
                    }
                    let shared = try localEphemeral.sharedSecretFromKeyAgreement(with: remoteStatic)
-                    symmetricState.mixKey(shared.withUnsafeBytes { Data($0) })
+                    var sharedData = shared.withUnsafeBytes { Data($0) }
+                    symmetricState.mixKey(sharedData)
+                    // Clear sensitive shared secret
+                    keychain.secureClear(&sharedData)
                }
                
            case .ss:
@@ -652,7 +719,7 @@ final class NoiseHandshakeState {
        guard currentPattern < messagePatterns.count else {
            throw NoiseError.handshakeComplete
        }
-                
+        
        var buffer = message
        let patterns = messagePatterns[currentPattern]
        
@@ -711,8 +778,11 @@ final class NoiseHandshakeState {
                throw NoiseError.missingKeys
            }
            let shared = try localEphemeral.sharedSecretFromKeyAgreement(with: remoteEphemeral)
-            symmetricState.mixKey(shared.withUnsafeBytes { Data($0) })
-            
+            var sharedData = shared.withUnsafeBytes { Data($0) }
+            symmetricState.mixKey(sharedData)
+            // Clear sensitive shared secret
+            keychain.secureClear(&sharedData)
+
        case .es:
            if role == .initiator {
                guard let localEphemeral = localEphemeralPrivate,
@@ -765,9 +835,12 @@ final class NoiseHandshakeState {
                throw NoiseError.missingKeys
            }
            let shared = try localStatic.sharedSecretFromKeyAgreement(with: remoteStatic)
-            symmetricState.mixKey(shared.withUnsafeBytes { Data($0) })
-            
-        default:
+            var sharedData = shared.withUnsafeBytes { Data($0) }
+            symmetricState.mixKey(sharedData)
+            // Clear sensitive shared secret
+            keychain.secureClear(&sharedData)
+
+        case .e, .s:
            break
        }
    }
@@ -776,16 +849,20 @@ final class NoiseHandshakeState {
        return currentPattern >= messagePatterns.count
    }
    
-    func getTransportCiphers() throws -> (send: NoiseCipherState, receive: NoiseCipherState) {
+    func getTransportCiphers(useExtractedNonce: Bool) throws -> (send: NoiseCipherState, receive: NoiseCipherState, handshakeHash: Data) {
        guard isHandshakeComplete() else {
            throw NoiseError.handshakeNotComplete
        }
-        
-        let (c1, c2) = symmetricState.split()
-        
+
+        // BCH-01-010: Capture handshake hash BEFORE split() clears symmetric state
+        let finalHandshakeHash = symmetricState.getHandshakeHash()
+
+        let (c1, c2) = symmetricState.split(useExtractedNonce: useExtractedNonce)
+
        // Initiator uses c1 for sending, c2 for receiving
        // Responder uses c2 for sending, c1 for receiving
-        return role == .initiator ? (c1, c2) : (c2, c1)
+        let ciphers = role == .initiator ? (c1, c2) : (c2, c1)
+        return (send: ciphers.0, receive: ciphers.1, handshakeHash: finalHandshakeHash)
    }
    
    func getRemoteStaticPublicKey() -> Curve25519.KeyAgreement.PublicKey? {
@@ -795,6 +872,20 @@ final class NoiseHandshakeState {
    func getHandshakeHash() -> Data {
        return symmetricState.getHandshakeHash()
    }
+
+    #if DEBUG
+    func performDHOperationForTesting(_ pattern: NoiseMessagePattern) throws {
+        try performDHOperation(pattern)
+    }
+
+    func setCurrentPatternForTesting(_ currentPattern: Int) {
+        self.currentPattern = currentPattern
+    }
+
+    func setRemoteEphemeralPublicKeyForTesting(_ key: Curve25519.KeyAgreement.PublicKey?) {
+        self.remoteEphemeralPublic = key
+    }
+    #endif
 }

 // MARK: - Pattern Extensions
@@ -846,22 +937,47 @@ enum NoiseError: Error {
    case nonceExceeded
 }

+// MARK: - Constant-Time Operations
+
+/// BCH-01-010: Constant-time comparison to prevent timing side-channel attacks
+/// This function compares two Data objects in constant time, preventing
+/// information leakage via timing analysis.
+private func constantTimeCompare(_ a: Data, _ b: Data) -> Bool {
+    guard a.count == b.count else { return false }
+
+    var result: UInt8 = 0
+    for i in 0..<a.count {
+        result |= a[a.startIndex.advanced(by: i)] ^ b[b.startIndex.advanced(by: i)]
+    }
+    return result == 0
+}
+
+/// BCH-01-010: Constant-time check if all bytes are zero
+private func constantTimeIsZero(_ data: Data) -> Bool {
+    var result: UInt8 = 0
+    for byte in data {
+        result |= byte
+    }
+    return result == 0
+}
+
 // MARK: - Key Validation

 extension NoiseHandshakeState {
    /// Validate a Curve25519 public key
    /// Checks for weak/invalid keys that could compromise security
+    /// BCH-01-010: Uses constant-time operations to prevent timing side-channels
    static func validatePublicKey(_ keyData: Data) throws -> Curve25519.KeyAgreement.PublicKey {
        // Check key length
        guard keyData.count == 32 else {
            throw NoiseError.invalidPublicKey
        }
-        
-        // Check for all-zero key (point at infinity)
-        if keyData.allSatisfy({ $0 == 0 }) {
+
+        // BCH-01-010: Constant-time check for all-zero key (point at infinity)
+        if constantTimeIsZero(keyData) {
            throw NoiseError.invalidPublicKey
        }
-        
+
        // Check for low-order points that could enable small subgroup attacks
        // These are the known bad points for Curve25519
        let lowOrderPoints: [Data] = [
@@ -882,13 +998,21 @@ extension NoiseHandshakeState {
                  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
                  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff])  // Another bad point
        ]
-        
-        // Check against known bad points
-        if lowOrderPoints.contains(keyData) {
+
+        // BCH-01-010: Constant-time check against known bad points
+        // We check all points and accumulate matches to avoid early exit timing leaks
+        var foundBadPoint = false
+        for badPoint in lowOrderPoints {
+            if constantTimeCompare(keyData, badPoint) {
+                foundBadPoint = true
+            }
+        }
+
+        if foundBadPoint {
            SecureLogger.warning("Low-order point detected", category: .security)
            throw NoiseError.invalidPublicKey
        }
-        
+
        // Try to create the key - CryptoKit will validate curve points internally
        do {
            let publicKey = try Curve25519.KeyAgreement.PublicKey(rawRepresentation: keyData)
@@ -0,0 +1,96 @@
+//
+// NoiseRateLimiter.swift
+// bitchat
+//
+// This is free and unencumbered software released into the public domain.
+// For more information, see <https://unlicense.org>
+//
+
+import BitLogger
+import BitFoundation
+import Foundation
+
+final class NoiseRateLimiter {
+    private var handshakeTimestamps: [PeerID: [Date]] = [:]
+    private var messageTimestamps: [PeerID: [Date]] = [:]
+    
+    // Global rate limiting
+    private var globalHandshakeTimestamps: [Date] = []
+    private var globalMessageTimestamps: [Date] = []
+    
+    private let queue = DispatchQueue(label: "chat.bitchat.noise.ratelimit", attributes: .concurrent)
+    
+    func allowHandshake(from peerID: PeerID) -> Bool {
+        return queue.sync(flags: .barrier) {
+            let now = Date()
+            let oneMinuteAgo = now.addingTimeInterval(-60)
+            
+            // Check global rate limit first
+            globalHandshakeTimestamps = globalHandshakeTimestamps.filter { $0 > oneMinuteAgo }
+            if globalHandshakeTimestamps.count >= NoiseSecurityConstants.maxGlobalHandshakesPerMinute {
+                SecureLogger.warning("Global handshake rate limit exceeded: \(globalHandshakeTimestamps.count)/\(NoiseSecurityConstants.maxGlobalHandshakesPerMinute) per minute", category: .security)
+                return false
+            }
+            
+            // Check per-peer rate limit
+            var timestamps = handshakeTimestamps[peerID] ?? []
+            timestamps = timestamps.filter { $0 > oneMinuteAgo }
+            
+            if timestamps.count >= NoiseSecurityConstants.maxHandshakesPerMinute {
+                SecureLogger.warning("Per-peer handshake rate limit exceeded for \(peerID): \(timestamps.count)/\(NoiseSecurityConstants.maxHandshakesPerMinute) per minute", category: .security)
+                return false
+            }
+            
+            // Record new handshake
+            timestamps.append(now)
+            handshakeTimestamps[peerID] = timestamps
+            globalHandshakeTimestamps.append(now)
+            return true
+        }
+    }
+    
+    func allowMessage(from peerID: PeerID) -> Bool {
+        return queue.sync(flags: .barrier) {
+            let now = Date()
+            let oneSecondAgo = now.addingTimeInterval(-1)
+            
+            // Check global rate limit first
+            globalMessageTimestamps = globalMessageTimestamps.filter { $0 > oneSecondAgo }
+            if globalMessageTimestamps.count >= NoiseSecurityConstants.maxGlobalMessagesPerSecond {
+                SecureLogger.warning("Global message rate limit exceeded: \(globalMessageTimestamps.count)/\(NoiseSecurityConstants.maxGlobalMessagesPerSecond) per second", category: .security)
+                return false
+            }
+            
+            // Check per-peer rate limit
+            var timestamps = messageTimestamps[peerID] ?? []
+            timestamps = timestamps.filter { $0 > oneSecondAgo }
+            
+            if timestamps.count >= NoiseSecurityConstants.maxMessagesPerSecond {
+                SecureLogger.warning("Per-peer message rate limit exceeded for \(peerID): \(timestamps.count)/\(NoiseSecurityConstants.maxMessagesPerSecond) per second", category: .security)
+                return false
+            }
+            
+            // Record new message
+            timestamps.append(now)
+            messageTimestamps[peerID] = timestamps
+            globalMessageTimestamps.append(now)
+            return true
+        }
+    }
+    
+    func reset(for peerID: PeerID) {
+        queue.async(flags: .barrier) {
+            self.handshakeTimestamps.removeValue(forKey: peerID)
+            self.messageTimestamps.removeValue(forKey: peerID)
+        }
+    }
+
+    func resetAll() {
+        queue.async(flags: .barrier) {
+            self.handshakeTimestamps.removeAll()
+            self.messageTimestamps.removeAll()
+            self.globalHandshakeTimestamps.removeAll()
+            self.globalMessageTimestamps.removeAll()
+        }
+    }
+}
@@ -1,227 +0,0 @@
-//
-// NoiseSecurityConsiderations.swift
-// bitchat
-//
-// This is free and unencumbered software released into the public domain.
-// For more information, see <https://unlicense.org>
-//
-
-import BitLogger
-import Foundation
-
-// MARK: - Security Constants
-
-enum NoiseSecurityConstants {
-    // Maximum message size to prevent memory exhaustion
-    static let maxMessageSize = 65535 // 64KB as per Noise spec
-    
-    // Maximum handshake message size
-    static let maxHandshakeMessageSize = 2048 // 2KB to accommodate XX pattern
-    
-    // Session timeout - sessions older than this should be renegotiated
-    static let sessionTimeout: TimeInterval = 86400 // 24 hours
-    
-    // Maximum number of messages before rekey (2^64 - 1 is the nonce limit)
-    static let maxMessagesPerSession: UInt64 = 1_000_000_000 // 1 billion messages
-    
-    // Handshake timeout - abandon incomplete handshakes
-    static let handshakeTimeout: TimeInterval = 60 // 1 minute
-    
-    // Maximum concurrent sessions per peer
-    static let maxSessionsPerPeer = 3
-    
-    // Rate limiting
-    static let maxHandshakesPerMinute = 10
-    static let maxMessagesPerSecond = 100
-    
-    // Global rate limiting (across all peers)
-    static let maxGlobalHandshakesPerMinute = 30
-    static let maxGlobalMessagesPerSecond = 500
-}
-
-// MARK: - Security Validations
-
-struct NoiseSecurityValidator {
-    
-    /// Validate message size
-    static func validateMessageSize(_ data: Data) -> Bool {
-        return data.count <= NoiseSecurityConstants.maxMessageSize
-    }
-    
-    /// Validate handshake message size
-    static func validateHandshakeMessageSize(_ data: Data) -> Bool {
-        return data.count <= NoiseSecurityConstants.maxHandshakeMessageSize
-    }
-}
-
-// MARK: - Enhanced Noise Session with Security
-
-final class SecureNoiseSession: NoiseSession {
-    private(set) var messageCount: UInt64 = 0
-    private let sessionStartTime = Date()
-    private(set) var lastActivityTime = Date()
-    
-    override func encrypt(_ plaintext: Data) throws -> Data {
-        // Check session age
-        if Date().timeIntervalSince(sessionStartTime) > NoiseSecurityConstants.sessionTimeout {
-            throw NoiseSecurityError.sessionExpired
-        }
-        
-        // Check message count
-        if messageCount >= NoiseSecurityConstants.maxMessagesPerSession {
-            throw NoiseSecurityError.sessionExhausted
-        }
-        
-        // Validate message size
-        guard NoiseSecurityValidator.validateMessageSize(plaintext) else {
-            throw NoiseSecurityError.messageTooLarge
-        }
-        
-        let encrypted = try super.encrypt(plaintext)
-        messageCount += 1
-        lastActivityTime = Date()
-        
-        return encrypted
-    }
-    
-    override func decrypt(_ ciphertext: Data) throws -> Data {
-        // Check session age
-        if Date().timeIntervalSince(sessionStartTime) > NoiseSecurityConstants.sessionTimeout {
-            throw NoiseSecurityError.sessionExpired
-        }
-        
-        // Validate message size
-        guard NoiseSecurityValidator.validateMessageSize(ciphertext) else {
-            throw NoiseSecurityError.messageTooLarge
-        }
-        
-        let decrypted = try super.decrypt(ciphertext)
-        lastActivityTime = Date()
-        
-        return decrypted
-    }
-    
-    func needsRenegotiation() -> Bool {
-        // Check if we've used more than 90% of message limit
-        let messageThreshold = UInt64(Double(NoiseSecurityConstants.maxMessagesPerSession) * 0.9)
-        if messageCount >= messageThreshold {
-            return true
-        }
-        
-        // Check if last activity was more than 30 minutes ago
-        if Date().timeIntervalSince(lastActivityTime) > NoiseSecurityConstants.sessionTimeout {
-            return true
-        }
-        
-        return false
-    }
-    
-    // MARK: - Testing Support
-    #if DEBUG
-    func setLastActivityTimeForTesting(_ date: Date) {
-        lastActivityTime = date
-    }
-    
-    func setMessageCountForTesting(_ count: UInt64) {
-        messageCount = count
-    }
-    #endif
-}
-
-// MARK: - Rate Limiter
-
-final class NoiseRateLimiter {
-    private var handshakeTimestamps: [PeerID: [Date]] = [:]
-    private var messageTimestamps: [PeerID: [Date]] = [:]
-    
-    // Global rate limiting
-    private var globalHandshakeTimestamps: [Date] = []
-    private var globalMessageTimestamps: [Date] = []
-    
-    private let queue = DispatchQueue(label: "chat.bitchat.noise.ratelimit", attributes: .concurrent)
-    
-    func allowHandshake(from peerID: PeerID) -> Bool {
-        return queue.sync(flags: .barrier) {
-            let now = Date()
-            let oneMinuteAgo = now.addingTimeInterval(-60)
-            
-            // Check global rate limit first
-            globalHandshakeTimestamps = globalHandshakeTimestamps.filter { $0 > oneMinuteAgo }
-            if globalHandshakeTimestamps.count >= NoiseSecurityConstants.maxGlobalHandshakesPerMinute {
-                SecureLogger.warning("Global handshake rate limit exceeded: \(globalHandshakeTimestamps.count)/\(NoiseSecurityConstants.maxGlobalHandshakesPerMinute) per minute", category: .security)
-                return false
-            }
-            
-            // Check per-peer rate limit
-            var timestamps = handshakeTimestamps[peerID] ?? []
-            timestamps = timestamps.filter { $0 > oneMinuteAgo }
-            
-            if timestamps.count >= NoiseSecurityConstants.maxHandshakesPerMinute {
-                SecureLogger.warning("Per-peer handshake rate limit exceeded for \(peerID): \(timestamps.count)/\(NoiseSecurityConstants.maxHandshakesPerMinute) per minute", category: .security)
-                return false
-            }
-            
-            // Record new handshake
-            timestamps.append(now)
-            handshakeTimestamps[peerID] = timestamps
-            globalHandshakeTimestamps.append(now)
-            return true
-        }
-    }
-    
-    func allowMessage(from peerID: PeerID) -> Bool {
-        return queue.sync(flags: .barrier) {
-            let now = Date()
-            let oneSecondAgo = now.addingTimeInterval(-1)
-            
-            // Check global rate limit first
-            globalMessageTimestamps = globalMessageTimestamps.filter { $0 > oneSecondAgo }
-            if globalMessageTimestamps.count >= NoiseSecurityConstants.maxGlobalMessagesPerSecond {
-                SecureLogger.warning("Global message rate limit exceeded: \(globalMessageTimestamps.count)/\(NoiseSecurityConstants.maxGlobalMessagesPerSecond) per second", category: .security)
-                return false
-            }
-            
-            // Check per-peer rate limit
-            var timestamps = messageTimestamps[peerID] ?? []
-            timestamps = timestamps.filter { $0 > oneSecondAgo }
-            
-            if timestamps.count >= NoiseSecurityConstants.maxMessagesPerSecond {
-                SecureLogger.warning("Per-peer message rate limit exceeded for \(peerID): \(timestamps.count)/\(NoiseSecurityConstants.maxMessagesPerSecond) per second", category: .security)
-                return false
-            }
-            
-            // Record new message
-            timestamps.append(now)
-            messageTimestamps[peerID] = timestamps
-            globalMessageTimestamps.append(now)
-            return true
-        }
-    }
-    
-    func reset(for peerID: PeerID) {
-        queue.async(flags: .barrier) {
-            self.handshakeTimestamps.removeValue(forKey: peerID)
-            self.messageTimestamps.removeValue(forKey: peerID)
-        }
-    }
-
-    func resetAll() {
-        queue.async(flags: .barrier) {
-            self.handshakeTimestamps.removeAll()
-            self.messageTimestamps.removeAll()
-            self.globalHandshakeTimestamps.removeAll()
-            self.globalMessageTimestamps.removeAll()
-        }
-    }
-}
-
-// MARK: - Security Errors
-
-enum NoiseSecurityError: Error {
-    case sessionExpired
-    case sessionExhausted
-    case messageTooLarge
-    case invalidPeerID
-    case rateLimitExceeded
-    case handshakeTimeout
-}
@@ -0,0 +1,37 @@
+//
+// NoiseSecurityConstants.swift
+// bitchat
+//
+// This is free and unencumbered software released into the public domain.
+// For more information, see <https://unlicense.org>
+//
+
+import Foundation
+
+enum NoiseSecurityConstants {
+    // Maximum message size to prevent memory exhaustion
+    static let maxMessageSize = 65535 // 64KB as per Noise spec
+    
+    // Maximum handshake message size
+    static let maxHandshakeMessageSize = 2048 // 2KB to accommodate XX pattern
+    
+    // Session timeout - sessions older than this should be renegotiated
+    static let sessionTimeout: TimeInterval = 86400 // 24 hours
+    
+    // Maximum number of messages before rekey (2^64 - 1 is the nonce limit)
+    static let maxMessagesPerSession: UInt64 = 1_000_000_000 // 1 billion messages
+    
+    // Handshake timeout - abandon incomplete handshakes
+    static let handshakeTimeout: TimeInterval = 60 // 1 minute
+    
+    // Maximum concurrent sessions per peer
+    static let maxSessionsPerPeer = 3
+    
+    // Rate limiting
+    static let maxHandshakesPerMinute = 10
+    static let maxMessagesPerSecond = 100
+    
+    // Global rate limiting (across all peers)
+    static let maxGlobalHandshakesPerMinute = 30
+    static let maxGlobalMessagesPerSecond = 500
+}
@@ -0,0 +1,18 @@
+//
+// NoiseSecurityError.swift
+// bitchat
+//
+// This is free and unencumbered software released into the public domain.
+// For more information, see <https://unlicense.org>
+//
+
+import Foundation
+
+enum NoiseSecurityError: Error {
+    case sessionExpired
+    case sessionExhausted
+    case messageTooLarge
+    case invalidPeerID
+    case rateLimitExceeded
+    case handshakeTimeout
+}
@@ -0,0 +1,22 @@
+//
+// NoiseSecurityValidator.swift
+// bitchat
+//
+// This is free and unencumbered software released into the public domain.
+// For more information, see <https://unlicense.org>
+//
+
+import Foundation
+
+struct NoiseSecurityValidator {
+    
+    /// Validate message size
+    static func validateMessageSize(_ data: Data) -> Bool {
+        return data.count <= NoiseSecurityConstants.maxMessageSize
+    }
+    
+    /// Validate handshake message size
+    static func validateHandshakeMessageSize(_ data: Data) -> Bool {
+        return data.count <= NoiseSecurityConstants.maxHandshakeMessageSize
+    }
+}
@@ -9,6 +9,7 @@
 import BitLogger
 import Foundation
 import CryptoKit
+import BitFoundation

 class NoiseSession {
    let peerID: PeerID
@@ -102,23 +103,23 @@ class NoiseSession {
            
            // Check if handshake is complete
            if handshake.isHandshakeComplete() {
-                // Get transport ciphers
-                let (send, receive) = try handshake.getTransportCiphers()
+                // Get transport ciphers and handshake hash (hash captured before split clears state)
+                let (send, receive, hash) = try handshake.getTransportCiphers(useExtractedNonce: true)
                sendCipher = send
                receiveCipher = receive
-                
+
                // Store remote static key
                remoteStaticPublicKey = handshake.getRemoteStaticPublicKey()
-                
+
                // Store handshake hash for channel binding
-                handshakeHash = handshake.getHandshakeHash()
-                
+                handshakeHash = hash
+
                state = .established
                handshakeState = nil // Clear handshake state
-                
+
                SecureLogger.debug("NoiseSession[\(peerID)]: Handshake complete (no response needed), transitioning to established")
                SecureLogger.info(.handshakeCompleted(peerID: peerID.id))
-                
+
                return nil
            } else {
                // Generate response
@@ -128,20 +129,20 @@ class NoiseSession {
                
                // Check if handshake is complete after writing
                if handshake.isHandshakeComplete() {
-                    // Get transport ciphers
-                    let (send, receive) = try handshake.getTransportCiphers()
+                    // Get transport ciphers and handshake hash (hash captured before split clears state)
+                    let (send, receive, hash) = try handshake.getTransportCiphers(useExtractedNonce: true)
                    sendCipher = send
                    receiveCipher = receive
-                    
+
                    // Store remote static key
                    remoteStaticPublicKey = handshake.getRemoteStaticPublicKey()
-                    
+
                    // Store handshake hash for channel binding
-                    handshakeHash = handshake.getHandshakeHash()
-                    
+                    handshakeHash = hash
+
                    state = .established
                    handshakeState = nil // Clear handshake state
-                    
+
                    SecureLogger.debug("NoiseSession[\(peerID)]: Handshake complete after writing response, transitioning to established")
                    SecureLogger.info(.handshakeCompleted(peerID: peerID.id))
                }
@@ -196,12 +197,6 @@ class NoiseSession {
        }
    }
    
-    func getHandshakeHash() -> Data? {
-        return sessionQueue.sync {
-            return handshakeHash
-        }
-    }
-    
    func reset() {
        sessionQueue.sync(flags: .barrier) {
            let wasEstablished = state == .established
@@ -6,10 +6,9 @@
 // For more information, see <https://unlicense.org>
 //

-enum NoiseSessionError: Error {
+enum NoiseSessionError: Error, Equatable {
    case invalidState
    case notEstablished
    case sessionNotFound
-    case handshakeFailed(Error)
    case alreadyEstablished
 }
@@ -9,11 +9,13 @@
 import BitLogger
 import CryptoKit
 import Foundation
+import BitFoundation

 final class NoiseSessionManager {
    private var sessions: [PeerID: NoiseSession] = [:]
    private let localStaticKey: Curve25519.KeyAgreement.PrivateKey
    private let keychain: KeychainManagerProtocol
+    private let sessionFactory: (PeerID, NoiseRole) -> NoiseSession
    private let managerQueue = DispatchQueue(label: "chat.bitchat.noise.manager", attributes: .concurrent)
    
    // Callbacks
@@ -23,22 +25,29 @@ final class NoiseSessionManager {
    init(localStaticKey: Curve25519.KeyAgreement.PrivateKey, keychain: KeychainManagerProtocol) {
        self.localStaticKey = localStaticKey
        self.keychain = keychain
-    }
-    
-    // MARK: - Session Management
-    
-    func createSession(for peerID: PeerID, role: NoiseRole) -> NoiseSession {
-        return managerQueue.sync(flags: .barrier) {
-            let session = SecureNoiseSession(
+        self.sessionFactory = { peerID, role in
+            SecureNoiseSession(
                peerID: peerID,
                role: role,
                keychain: keychain,
                localStaticKey: localStaticKey
            )
-            sessions[peerID] = session
-            return session
        }
    }
+
+    #if DEBUG
+    init(
+        localStaticKey: Curve25519.KeyAgreement.PrivateKey,
+        keychain: KeychainManagerProtocol,
+        sessionFactory: @escaping (PeerID, NoiseRole) -> NoiseSession
+    ) {
+        self.localStaticKey = localStaticKey
+        self.keychain = keychain
+        self.sessionFactory = sessionFactory
+    }
+    #endif
+    
+    // MARK: - Session Management
    
    func getSession(for peerID: PeerID) -> NoiseSession? {
        return managerQueue.sync {
@@ -48,14 +57,9 @@ final class NoiseSessionManager {
    
    func removeSession(for peerID: PeerID) {
        managerQueue.sync(flags: .barrier) {
-            if let session = sessions[peerID] {
-                if session.isEstablished() {
-                    SecureLogger.info(.sessionExpired(peerID: peerID.id))
-                }
-                // Clear sensitive data before removing
-                session.reset()
+            if let session = sessions.removeValue(forKey: peerID) {
+                session.reset() // Clear sensitive data before removing
            }
-            _ = sessions.removeValue(forKey: peerID)
        }
    }

@@ -68,12 +72,6 @@ final class NoiseSessionManager {
        }
    }
    
-    func getEstablishedSessions() -> [PeerID: NoiseSession] {
-        return managerQueue.sync {
-            return sessions.filter { $0.value.isEstablished() }
-        }
-    }
-    
    // MARK: - Handshake Helpers
    
    func initiateHandshake(with peerID: PeerID) throws -> Data {
@@ -90,12 +88,7 @@ final class NoiseSessionManager {
            }
            
            // Create new initiator session
-            let session = SecureNoiseSession(
-                peerID: peerID,
-                role: .initiator,
-                keychain: keychain,
-                localStaticKey: localStaticKey
-            )
+            let session = sessionFactory(peerID, .initiator)
            sessions[peerID] = session
            
            do {
@@ -141,12 +134,7 @@ final class NoiseSessionManager {
            // Get or create session
            let session: NoiseSession
            if shouldCreateNew {
-                let newSession = SecureNoiseSession(
-                    peerID: peerID,
-                    role: .responder,
-                    keychain: keychain,
-                    localStaticKey: localStaticKey
-                )
+                let newSession = sessionFactory(peerID, .responder)
                sessions[peerID] = newSession
                session = newSession
            } else {
@@ -207,10 +195,6 @@ final class NoiseSessionManager {
        return getSession(for: peerID)?.getRemoteStaticPublicKey()
    }
    
-    func getHandshakeHash(for peerID: PeerID) -> Data? {
-        return getSession(for: peerID)?.getHandshakeHash()
-    }
-    
    // MARK: - Session Rekeying
    
    func getSessionsNeedingRekey() -> [(peerID: PeerID, needsRekey: Bool)] {
@@ -0,0 +1,85 @@
+//
+// SecureNoiseSession.swift
+// bitchat
+//
+// This is free and unencumbered software released into the public domain.
+// For more information, see <https://unlicense.org>
+//
+
+import Foundation
+
+final class SecureNoiseSession: NoiseSession {
+    private(set) var messageCount: UInt64 = 0
+    private var sessionStartTime = Date()
+    private(set) var lastActivityTime = Date()
+    
+    override func encrypt(_ plaintext: Data) throws -> Data {
+        // Check session age
+        if Date().timeIntervalSince(sessionStartTime) > NoiseSecurityConstants.sessionTimeout {
+            throw NoiseSecurityError.sessionExpired
+        }
+        
+        // Check message count
+        if messageCount >= NoiseSecurityConstants.maxMessagesPerSession {
+            throw NoiseSecurityError.sessionExhausted
+        }
+        
+        // Validate message size
+        guard NoiseSecurityValidator.validateMessageSize(plaintext) else {
+            throw NoiseSecurityError.messageTooLarge
+        }
+        
+        let encrypted = try super.encrypt(plaintext)
+        messageCount += 1
+        lastActivityTime = Date()
+        
+        return encrypted
+    }
+    
+    override func decrypt(_ ciphertext: Data) throws -> Data {
+        // Check session age
+        if Date().timeIntervalSince(sessionStartTime) > NoiseSecurityConstants.sessionTimeout {
+            throw NoiseSecurityError.sessionExpired
+        }
+        
+        // Validate message size
+        guard NoiseSecurityValidator.validateMessageSize(ciphertext) else {
+            throw NoiseSecurityError.messageTooLarge
+        }
+        
+        let decrypted = try super.decrypt(ciphertext)
+        lastActivityTime = Date()
+        
+        return decrypted
+    }
+    
+    func needsRenegotiation() -> Bool {
+        // Check if we've used more than 90% of message limit
+        let messageThreshold = UInt64(Double(NoiseSecurityConstants.maxMessagesPerSession) * 0.9)
+        if messageCount >= messageThreshold {
+            return true
+        }
+        
+        // Check if last activity was more than 30 minutes ago
+        if Date().timeIntervalSince(lastActivityTime) > NoiseSecurityConstants.sessionTimeout {
+            return true
+        }
+        
+        return false
+    }
+    
+    // MARK: - Testing Support
+    #if DEBUG
+    func setLastActivityTimeForTesting(_ date: Date) {
+        lastActivityTime = date
+    }
+    
+    func setMessageCountForTesting(_ count: UInt64) {
+        messageCount = count
+    }
+
+    func setSessionStartTimeForTesting(_ date: Date) {
+        sessionStartTime = date
+    }
+    #endif
+}
@@ -0,0 +1,135 @@
+import Foundation
+
+/// Bech32 encoding for Nostr (minimal implementation)
+enum Bech32 {
+    private static let charset = "qpzry9x8gf2tvdw0s3jn54khce6mua7l"
+    private static let generator = [0x3b6a57b2, 0x26508e6d, 0x1ea119fa, 0x3d4233dd, 0x2a1462b3]
+    
+    static func encode(hrp: String, data: Data) throws -> String {
+        let values = convertBits(from: 8, to: 5, pad: true, data: Array(data))
+        let checksum = createChecksum(hrp: hrp, values: values)
+        let combined = values + checksum
+        
+        return hrp + "1" + combined.map { 
+            let index = charset.index(charset.startIndex, offsetBy: Int($0))
+            return String(charset[index])
+        }.joined()
+    }
+    
+    static func decode(_ bech32String: String) throws -> (hrp: String, data: Data) {
+        // Find the last occurrence of '1'
+        guard let separatorIndex = bech32String.lastIndex(of: "1") else {
+            throw Bech32Error.invalidFormat
+        }
+        
+        let hrp = String(bech32String[..<separatorIndex])
+        
+        // Validate HRP contains only ASCII characters
+        for char in hrp {
+            guard char.asciiValue != nil else {
+                throw Bech32Error.invalidCharacter
+            }
+        }
+        
+        let dataString = String(bech32String[bech32String.index(after: separatorIndex)...])
+        
+        // Convert characters to values
+        var values = [UInt8]()
+        for char in dataString {
+            guard let index = charset.firstIndex(of: char) else {
+                throw Bech32Error.invalidCharacter
+            }
+            values.append(UInt8(charset.distance(from: charset.startIndex, to: index)))
+        }
+        
+        // Verify checksum
+        guard values.count >= 6 else {
+            throw Bech32Error.invalidChecksum
+        }
+        
+        let payloadValues = Array(values.dropLast(6))
+        let checksum = Array(values.suffix(6))
+        let expectedChecksum = createChecksum(hrp: hrp, values: payloadValues)
+        
+        guard checksum == expectedChecksum else {
+            throw Bech32Error.invalidChecksum
+        }
+        
+        // Convert back to bytes
+        let bytes = convertBits(from: 5, to: 8, pad: false, data: payloadValues)
+        return (hrp: hrp, data: Data(bytes))
+    }
+    
+    enum Bech32Error: Error {
+        case invalidFormat
+        case invalidCharacter
+        case invalidChecksum
+    }
+    
+    private static func convertBits(from: Int, to: Int, pad: Bool, data: [UInt8]) -> [UInt8] {
+        var acc = 0
+        var bits = 0
+        var result = [UInt8]()
+        let maxv = (1 << to) - 1
+        
+        for value in data {
+            acc = (acc << from) | Int(value)
+            bits += from
+            
+            while bits >= to {
+                bits -= to
+                result.append(UInt8((acc >> bits) & maxv))
+            }
+        }
+        
+        if pad && bits > 0 {
+            result.append(UInt8((acc << (to - bits)) & maxv))
+        }
+        
+        return result
+    }
+    
+    private static func createChecksum(hrp: String, values: [UInt8]) -> [UInt8] {
+        let checksumValues = hrpExpand(hrp) + values + [0, 0, 0, 0, 0, 0]
+        let polymod = polymod(checksumValues) ^ 1
+        var checksum = [UInt8]()
+        
+        for i in 0..<6 {
+            checksum.append(UInt8((polymod >> (5 * (5 - i))) & 31))
+        }
+        
+        return checksum
+    }
+    
+    private static func hrpExpand(_ hrp: String) -> [UInt8] {
+        var result = [UInt8]()
+        for c in hrp {
+            guard let asciiValue = c.asciiValue else {
+                return [] // Return empty array for invalid input
+            }
+            result.append(UInt8(asciiValue >> 5))
+        }
+        result.append(0)
+        for c in hrp {
+            guard let asciiValue = c.asciiValue else {
+                return [] // Return empty array for invalid input
+            }
+            result.append(UInt8(asciiValue & 31))
+        }
+        return result
+    }
+    
+    private static func polymod(_ values: [UInt8]) -> Int {
+        var chk = 1
+        for value in values {
+            let b = chk >> 25
+            chk = (chk & 0x1ffffff) << 5 ^ Int(value)
+            for i in 0..<5 {
+                if (b >> i) & 1 == 1 {
+                    chk ^= generator[i]
+                }
+            }
+        }
+        return chk
+    }
+}
@@ -1,28 +1,161 @@
 import BitLogger
 import Foundation
 import Tor
+#if os(iOS)
+import UIKit
+#elseif os(macOS)
+import AppKit
+#endif

 /// Directory of online Nostr relays with approximate GPS locations, used for geohash routing.
+struct GeoRelayDirectoryDependencies {
+    var userDefaults: UserDefaults
+    var notificationCenter: NotificationCenter
+    var now: () -> Date
+    var remoteURL: URL
+    var fetchInterval: TimeInterval
+    var refreshCheckInterval: TimeInterval
+    var retryInitialSeconds: TimeInterval
+    var retryMaxSeconds: TimeInterval
+    var awaitTorReady: @Sendable () async -> Bool
+    var makeFetchData: @MainActor @Sendable () -> (@Sendable (URLRequest) async throws -> Data)
+    var readData: (URL) -> Data?
+    var writeData: (Data, URL) throws -> Void
+    var cacheURL: () -> URL?
+    var bundledCSVURLs: () -> [URL]
+    var currentDirectoryPath: () -> String?
+    var retrySleep: (TimeInterval) async -> Void
+    var activeNotificationName: Notification.Name?
+    var autoStart: Bool
+}
+
+private extension GeoRelayDirectoryDependencies {
+    @MainActor
+    static func live() -> Self {
+#if os(iOS)
+        let activeNotificationName: Notification.Name? = UIApplication.didBecomeActiveNotification
+#elseif os(macOS)
+        let activeNotificationName: Notification.Name? = NSApplication.didBecomeActiveNotification
+#else
+        let activeNotificationName: Notification.Name? = nil
+#endif
+
+        return Self(
+            userDefaults: .standard,
+            notificationCenter: .default,
+            now: Date.init,
+            remoteURL: URL(string: "https://raw.githubusercontent.com/permissionlesstech/georelays/refs/heads/main/nostr_relays.csv")!,
+            fetchInterval: TransportConfig.geoRelayFetchIntervalSeconds,
+            refreshCheckInterval: TransportConfig.geoRelayRefreshCheckIntervalSeconds,
+            retryInitialSeconds: TransportConfig.geoRelayRetryInitialSeconds,
+            retryMaxSeconds: TransportConfig.geoRelayRetryMaxSeconds,
+            awaitTorReady: { await TorManager.shared.awaitReady() },
+            makeFetchData: {
+                let session = TorURLSession.shared.session
+                return { request in
+                    let (data, _) = try await session.data(for: request)
+                    return data
+                }
+            },
+            readData: { try? Data(contentsOf: $0) },
+            writeData: { data, url in
+                try data.write(to: url, options: .atomic)
+            },
+            cacheURL: {
+                do {
+                    let base = try FileManager.default.url(
+                        for: .applicationSupportDirectory,
+                        in: .userDomainMask,
+                        appropriateFor: nil,
+                        create: true
+                    )
+                    let dir = base.appendingPathComponent("bitchat", isDirectory: true)
+                    try? FileManager.default.createDirectory(at: dir, withIntermediateDirectories: true)
+                    return dir.appendingPathComponent("georelays_cache.csv")
+                } catch {
+                    return nil
+                }
+            },
+            bundledCSVURLs: {
+                [
+                    Bundle.main.url(forResource: "nostr_relays", withExtension: "csv"),
+                    Bundle.main.url(forResource: "online_relays_gps", withExtension: "csv"),
+                    Bundle.main.url(forResource: "online_relays_gps", withExtension: "csv", subdirectory: "relays")
+                ].compactMap { $0 }
+            },
+            currentDirectoryPath: { FileManager.default.currentDirectoryPath },
+            retrySleep: { delay in
+                let nanoseconds = UInt64(delay * 1_000_000_000)
+                try? await Task.sleep(nanoseconds: nanoseconds)
+            },
+            activeNotificationName: activeNotificationName,
+            autoStart: true
+        )
+    }
+}
+
@MainActor
 final class GeoRelayDirectory {
-    struct Entry: Hashable {
+    private final class CleanupState {
+        let notificationCenter: NotificationCenter
+        var observers: [NSObjectProtocol] = []
+        var refreshTimer: Timer?
+        var retryTask: Task<Void, Never>?
+
+        init(notificationCenter: NotificationCenter) {
+            self.notificationCenter = notificationCenter
+        }
+
+        deinit {
+            observers.forEach { notificationCenter.removeObserver($0) }
+            refreshTimer?.invalidate()
+            retryTask?.cancel()
+        }
+    }
+
+    struct Entry: Hashable, Sendable {
        let host: String
        let lat: Double
        let lon: Double
    }

+    private enum DetachedFetchOutcome: Sendable {
+        case success(entries: [Entry], csv: String)
+        case torNotReady
+        case invalidData
+        case network(String)
+    }
+
    static let shared = GeoRelayDirectory()
+
    private(set) var entries: [Entry] = []
-    private let cacheFileName = "georelays_cache.csv"
    private let lastFetchKey = "georelay.lastFetchAt"
-    private let remoteURL = URL(string: "https://raw.githubusercontent.com/permissionlesstech/georelays/refs/heads/main/nostr_relays.csv")!
-    private let fetchInterval: TimeInterval = TransportConfig.geoRelayFetchIntervalSeconds // 24h
+    private let dependencies: GeoRelayDirectoryDependencies
+    private let cleanupState: CleanupState
+
+    private var retryAttempt: Int = 0
+    private var isFetching: Bool = false

    private init() {
-        // Load cached or bundled data synchronously
-        self.entries = self.loadLocalEntries()
-        // Fire-and-forget remote refresh if stale
-        prefetchIfNeeded()
+        self.dependencies = .live()
+        self.cleanupState = CleanupState(notificationCenter: dependencies.notificationCenter)
+        entries = loadLocalEntries()
+        if dependencies.autoStart {
+            registerObservers()
+            startRefreshTimer()
+            prefetchIfNeeded()
+        }
+    }
+
+    internal init(dependencies: GeoRelayDirectoryDependencies) {
+        self.dependencies = dependencies
+        self.cleanupState = CleanupState(notificationCenter: dependencies.notificationCenter)
+        entries = loadLocalEntries()
+        if dependencies.autoStart {
+            registerObservers()
+            startRefreshTimer()
+            prefetchIfNeeded()
+        }
    }

    /// Returns up to `count` relay URLs (wss://) closest to the geohash center.
@@ -33,56 +166,176 @@ final class GeoRelayDirectory {

    /// Returns up to `count` relay URLs (wss://) closest to the given coordinate.
    func closestRelays(toLat lat: Double, lon: Double, count: Int = 5) -> [String] {
-        guard !entries.isEmpty else { return [] }
-        let sorted = entries
-            .sorted { a, b in
-                haversineKm(lat, lon, a.lat, a.lon) < haversineKm(lat, lon, b.lat, b.lon)
+        guard !entries.isEmpty, count > 0 else { return [] }
+
+        if entries.count <= count {
+            return entries
+                .sorted { a, b in
+                    haversineKm(lat, lon, a.lat, a.lon) < haversineKm(lat, lon, b.lat, b.lon)
+                }
+                .map { "wss://\($0.host)" }
+        }
+
+        var best: [(entry: Entry, distance: Double)] = []
+        best.reserveCapacity(count)
+
+        for entry in entries {
+            let distance = haversineKm(lat, lon, entry.lat, entry.lon)
+            if best.count < count {
+                let idx = best.firstIndex { $0.distance > distance } ?? best.count
+                best.insert((entry, distance), at: idx)
+            } else if let worstDistance = best.last?.distance, distance < worstDistance {
+                let idx = best.firstIndex { $0.distance > distance } ?? best.count
+                best.insert((entry, distance), at: idx)
+                best.removeLast()
            }
-            .prefix(count)
-        return sorted.map { "wss://\($0.host)" }
+        }
+
+        return best.map { "wss://\($0.entry.host)" }
    }

    // MARK: - Remote Fetch
-    func prefetchIfNeeded() {
-        let now = Date()
-        let last = UserDefaults.standard.object(forKey: lastFetchKey) as? Date ?? .distantPast
-        guard now.timeIntervalSince(last) >= fetchInterval else { return }
+    func prefetchIfNeeded(force: Bool = false) {
+        guard !isFetching else { return }
+
+        let now = dependencies.now()
+        let last = dependencies.userDefaults.object(forKey: lastFetchKey) as? Date ?? .distantPast
+
+        if !force {
+            guard now.timeIntervalSince(last) >= dependencies.fetchInterval else { return }
+        } else if last != .distantPast,
+                  now.timeIntervalSince(last) < dependencies.retryInitialSeconds {
+            // Skip forced fetches if we just refreshed moments ago.
+            return
+        }
+
+        cancelRetry()
        fetchRemote()
    }

    private func fetchRemote() {
-        let req = URLRequest(url: remoteURL, cachePolicy: .reloadIgnoringLocalCacheData, timeoutInterval: 15)
-        // Ensure Tor readiness before fetching (fail-closed by default)
-        Task.detached {
-            let ready = await TorManager.shared.awaitReady()
-            if !ready {
-                SecureLogger.warning("GeoRelayDirectory: Tor not ready; skipping remote fetch (fail-closed)", category: .session)
-                return
+        guard !isFetching else { return }
+        isFetching = true
+
+        let request = URLRequest(
+            url: dependencies.remoteURL,
+            cachePolicy: .reloadIgnoringLocalCacheData,
+            timeoutInterval: 15
+        )
+        let awaitTorReady = dependencies.awaitTorReady
+        let fetchData = dependencies.makeFetchData()
+
+        Task { [weak self] in
+            guard let self else { return }
+
+            let outcome = await Self.fetchRemoteOutcome(
+                request: request,
+                awaitTorReady: awaitTorReady,
+                fetchData: fetchData
+            )
+
+            switch outcome {
+            case .success(let parsed, let csv):
+                self.handleFetchSuccess(entries: parsed, csv: csv)
+            case .torNotReady:
+                self.handleFetchFailure(.torNotReady)
+            case .invalidData:
+                self.handleFetchFailure(.invalidData)
+            case .network(let description):
+                self.handleFetchFailure(.network(description))
            }
-            let task = TorURLSession.shared.session.dataTask(with: req) { [weak self] data, _, error in
-                guard let self = self else { return }
-                if let data = data, error == nil, let text = String(data: data, encoding: .utf8) {
-                    let parsed = GeoRelayDirectory.parseCSV(text)
-                    if !parsed.isEmpty {
-                        Task { @MainActor in
-                            self.entries = parsed
-                            self.persistCache(text)
-                            UserDefaults.standard.set(Date(), forKey: self.lastFetchKey)
-                            SecureLogger.info("GeoRelayDirectory: refreshed \(parsed.count) relays from remote", category: .session)
-                        }
-                        return
-                    }
-                }
-                SecureLogger.warning("GeoRelayDirectory: remote fetch failed; keeping local entries", category: .session)
-            }
-            task.resume()
        }
    }

+    nonisolated private static func fetchRemoteOutcome(
+        request: URLRequest,
+        awaitTorReady: @escaping @Sendable () async -> Bool,
+        fetchData: @escaping @Sendable (URLRequest) async throws -> Data
+    ) async -> DetachedFetchOutcome {
+        await Task.detached(priority: .utility) {
+            let ready = await awaitTorReady()
+            guard ready else { return .torNotReady }
+
+            do {
+                let data = try await fetchData(request)
+                guard let text = String(data: data, encoding: .utf8) else {
+                    return .invalidData
+                }
+
+                let parsed = Self.parseCSV(text)
+                guard !parsed.isEmpty else {
+                    return .invalidData
+                }
+
+                return .success(entries: parsed, csv: text)
+            } catch {
+                return .network(error.localizedDescription)
+            }
+        }.value
+    }
+
+    private enum FetchFailure {
+        case torNotReady
+        case invalidData
+        case network(String)
+    }
+
+    @MainActor
+    private func handleFetchSuccess(entries parsed: [Entry], csv: String) {
+        entries = parsed
+        persistCache(csv)
+        dependencies.userDefaults.set(dependencies.now(), forKey: lastFetchKey)
+        SecureLogger.info("GeoRelayDirectory: refreshed \(parsed.count) relays from remote", category: .session)
+        isFetching = false
+        retryAttempt = 0
+        cancelRetry()
+    }
+
+    @MainActor
+    private func handleFetchFailure(_ reason: FetchFailure) {
+        switch reason {
+        case .torNotReady:
+            SecureLogger.warning("GeoRelayDirectory: Tor not ready; scheduling retry", category: .session)
+        case .invalidData:
+            SecureLogger.warning("GeoRelayDirectory: remote fetch returned invalid data; scheduling retry", category: .session)
+        case .network(let errorDescription):
+            SecureLogger.warning("GeoRelayDirectory: remote fetch failed with error: \(errorDescription)", category: .session)
+        }
+        isFetching = false
+        scheduleRetry()
+    }
+
+    @MainActor
+    private func scheduleRetry() {
+        retryAttempt = min(retryAttempt + 1, 10)
+        let base = dependencies.retryInitialSeconds
+        let maxDelay = dependencies.retryMaxSeconds
+        let multiplier = pow(2.0, Double(max(retryAttempt - 1, 0)))
+        let calculated = base * multiplier
+        let delay = min(maxDelay, max(base, calculated))
+
+        cancelRetry()
+        cleanupState.retryTask = Task { [weak self] in
+            guard let self else { return }
+            await self.dependencies.retrySleep(delay)
+            guard !Task.isCancelled else { return }
+            await MainActor.run {
+                self.prefetchIfNeeded(force: true)
+            }
+        }
+    }
+
+    @MainActor
+    private func cancelRetry() {
+        cleanupState.retryTask?.cancel()
+        cleanupState.retryTask = nil
+    }
+
    private func persistCache(_ text: String) {
-        guard let url = cacheURL() else { return }
+        guard let url = dependencies.cacheURL() else { return }
+        guard let data = text.data(using: .utf8) else { return }
        do {
-            try text.data(using: .utf8)?.write(to: url, options: .atomic)
+            try dependencies.writeData(data, url)
        } catch {
            SecureLogger.warning("GeoRelayDirectory: failed to write cache: \(error)", category: .session)
        }
@@ -91,30 +344,31 @@ final class GeoRelayDirectory {
    // MARK: - Loading
    private func loadLocalEntries() -> [Entry] {
        // Prefer cached file if present
-        if let cache = self.cacheURL(),
-           let data = try? Data(contentsOf: cache),
+        if let cache = dependencies.cacheURL(),
+           let data = dependencies.readData(cache),
           let text = String(data: data, encoding: .utf8) {
            let arr = Self.parseCSV(text)
            if !arr.isEmpty { return arr }
        }
+
        // Try bundled resource(s)
-        let bundleCandidates = [
-            Bundle.main.url(forResource: "nostr_relays", withExtension: "csv"),
-            Bundle.main.url(forResource: "online_relays_gps", withExtension: "csv"),
-            Bundle.main.url(forResource: "online_relays_gps", withExtension: "csv", subdirectory: "relays")
-        ].compactMap { $0 }
+        let bundleCandidates = dependencies.bundledCSVURLs()
+
        for url in bundleCandidates {
-            if let data = try? Data(contentsOf: url), let text = String(data: data, encoding: .utf8) {
+            if let data = dependencies.readData(url),
+               let text = String(data: data, encoding: .utf8) {
                let arr = Self.parseCSV(text)
                if !arr.isEmpty { return arr }
            }
        }
+
        // Try filesystem path (development/test)
-        if let cwd = FileManager.default.currentDirectoryPath as String?,
-           let data = try? Data(contentsOf: URL(fileURLWithPath: cwd).appendingPathComponent("relays/online_relays_gps.csv")),
+        if let cwd = dependencies.currentDirectoryPath(),
+           let data = dependencies.readData(URL(fileURLWithPath: cwd).appendingPathComponent("relays/online_relays_gps.csv")),
           let text = String(data: data, encoding: .utf8) {
            return Self.parseCSV(text)
        }
+
        SecureLogger.warning("GeoRelayDirectory: no local CSV found; entries empty", category: .session)
        return []
    }
@@ -122,12 +376,10 @@ final class GeoRelayDirectory {
    nonisolated static func parseCSV(_ text: String) -> [Entry] {
        var result: Set<Entry> = []
        let lines = text.split(whereSeparator: { $0.isNewline })
-        // Skip header if present
        for (idx, raw) in lines.enumerated() {
-            let line = raw.trimmingCharacters(in: .whitespacesAndNewlines)
-            if line.isEmpty { continue }
+            guard let line = raw.trimmedOrNilIfEmpty else { continue }
            if idx == 0 && line.lowercased().contains("relay url") { continue }
-            let parts = line.split(separator: ",").map { String($0).trimmingCharacters(in: .whitespaces) }
+            let parts = line.split(separator: ",").map { $0.trimmed }
            guard parts.count >= 3 else { continue }
            var host = parts[0]
            host = host.replacingOccurrences(of: "https://", with: "")
@@ -141,14 +393,55 @@ final class GeoRelayDirectory {
        return Array(result)
    }

-    private func cacheURL() -> URL? {
-        do {
-            let base = try FileManager.default.url(for: .applicationSupportDirectory, in: .userDomainMask, appropriateFor: nil, create: true)
-            let dir = base.appendingPathComponent("bitchat", isDirectory: true)
-            try? FileManager.default.createDirectory(at: dir, withIntermediateDirectories: true)
-            return dir.appendingPathComponent(cacheFileName)
-        } catch { return nil }
+    // MARK: - Observers & Timers
+    private func registerObservers() {
+        let center = dependencies.notificationCenter
+
+        let torReady = center.addObserver(
+            forName: .TorDidBecomeReady,
+            object: nil,
+            queue: .main
+        ) { [weak self] _ in
+            guard let self else { return }
+            Task { @MainActor in
+                self.prefetchIfNeeded(force: true)
+            }
+        }
+        cleanupState.observers.append(torReady)
+
+        if let activeNotificationName = dependencies.activeNotificationName {
+            let didBecomeActive = center.addObserver(
+                forName: activeNotificationName,
+                object: nil,
+                queue: .main
+            ) { [weak self] _ in
+                guard let self else { return }
+                Task { @MainActor in
+                    self.prefetchIfNeeded()
+                }
+            }
+            cleanupState.observers.append(didBecomeActive)
+        }
    }
+
+    private func startRefreshTimer() {
+        cleanupState.refreshTimer?.invalidate()
+        let interval = dependencies.refreshCheckInterval
+        guard interval > 0 else { return }
+
+        let timer = Timer.scheduledTimer(withTimeInterval: interval, repeats: true) { [weak self] _ in
+            guard let self else { return }
+            Task { @MainActor in
+                self.prefetchIfNeeded()
+            }
+        }
+        cleanupState.refreshTimer = timer
+        RunLoop.main.add(timer, forMode: .common)
+    }
+
+    var debugRetryAttempt: Int { retryAttempt }
+    var debugHasRetryTask: Bool { cleanupState.retryTask != nil }
+    var debugObserverCount: Int { cleanupState.observers.count }
 }

 // MARK: - Distance
@@ -1,10 +1,11 @@
 import Foundation
+import BitFoundation

 // MARK: - BitChat-over-Nostr Adapter

 struct NostrEmbeddedBitChat {
    /// Build a `bitchat1:` base64url-encoded BitChat packet carrying a private message for Nostr DMs.
-    static func encodePMForNostr(content: String, messageID: String, recipientPeerID: String, senderPeerID: String) -> String? {
+    static func encodePMForNostr(content: String, messageID: String, recipientPeerID: PeerID, senderPeerID: PeerID) -> String? {
        // TLV-encode the private message
        let pm = PrivateMessagePacket(messageID: messageID, content: content)
        guard let tlv = pm.encode() else { return nil }
@@ -14,12 +15,12 @@ struct NostrEmbeddedBitChat {
        payload.append(tlv)

        // Determine 8-byte recipient ID to embed
-        let recipientIDHex: String = normalizeRecipientPeerID(recipientPeerID)
+        let recipientID = normalizeRecipientPeerID(recipientPeerID)

        let packet = BitchatPacket(
            type: MessageType.noiseEncrypted.rawValue,
-            senderID: Data(hexString: senderPeerID) ?? Data(),
-            recipientID: Data(hexString: recipientIDHex),
+            senderID: Data(hexString: senderPeerID.id) ?? Data(),
+            recipientID: Data(hexString: recipientID.id),
            timestamp: UInt64(Date().timeIntervalSince1970 * 1000),
            payload: payload,
            signature: nil,
@@ -31,18 +32,18 @@ struct NostrEmbeddedBitChat {
    }

    /// Build a `bitchat1:` base64url-encoded BitChat packet carrying a delivery/read ack for Nostr DMs.
-    static func encodeAckForNostr(type: NoisePayloadType, messageID: String, recipientPeerID: String, senderPeerID: String) -> String? {
+    static func encodeAckForNostr(type: NoisePayloadType, messageID: String, recipientPeerID: PeerID, senderPeerID: PeerID) -> String? {
        guard type == .delivered || type == .readReceipt else { return nil }

        var payload = Data([type.rawValue])
        payload.append(Data(messageID.utf8))

-        let recipientIDHex: String = normalizeRecipientPeerID(recipientPeerID)
+        let recipientID = normalizeRecipientPeerID(recipientPeerID)

        let packet = BitchatPacket(
            type: MessageType.noiseEncrypted.rawValue,
-            senderID: Data(hexString: senderPeerID) ?? Data(),
-            recipientID: Data(hexString: recipientIDHex),
+            senderID: Data(hexString: senderPeerID.id) ?? Data(),
+            recipientID: Data(hexString: recipientID.id),
            timestamp: UInt64(Date().timeIntervalSince1970 * 1000),
            payload: payload,
            signature: nil,
@@ -54,7 +55,7 @@ struct NostrEmbeddedBitChat {
    }

    /// Build a `bitchat1:` ACK (delivered/read) without an embedded recipient peer ID (geohash DMs).
-    static func encodeAckForNostrNoRecipient(type: NoisePayloadType, messageID: String, senderPeerID: String) -> String? {
+    static func encodeAckForNostrNoRecipient(type: NoisePayloadType, messageID: String, senderPeerID: PeerID) -> String? {
        guard type == .delivered || type == .readReceipt else { return nil }

        var payload = Data([type.rawValue])
@@ -62,7 +63,7 @@ struct NostrEmbeddedBitChat {

        let packet = BitchatPacket(
            type: MessageType.noiseEncrypted.rawValue,
-            senderID: Data(hexString: senderPeerID) ?? Data(),
+            senderID: Data(hexString: senderPeerID.id) ?? Data(),
            recipientID: nil,
            timestamp: UInt64(Date().timeIntervalSince1970 * 1000),
            payload: payload,
@@ -75,7 +76,7 @@ struct NostrEmbeddedBitChat {
    }

    /// Build a `bitchat1:` payload without an embedded recipient peer ID (used for geohash DMs).
-    static func encodePMForNostrNoRecipient(content: String, messageID: String, senderPeerID: String) -> String? {
+    static func encodePMForNostrNoRecipient(content: String, messageID: String, senderPeerID: PeerID) -> String? {
        let pm = PrivateMessagePacket(messageID: messageID, content: content)
        guard let tlv = pm.encode() else { return nil }

@@ -84,7 +85,7 @@ struct NostrEmbeddedBitChat {

        let packet = BitchatPacket(
            type: MessageType.noiseEncrypted.rawValue,
-            senderID: Data(hexString: senderPeerID) ?? Data(),
+            senderID: Data(hexString: senderPeerID.id) ?? Data(),
            recipientID: nil,
            timestamp: UInt64(Date().timeIntervalSince1970 * 1000),
            payload: payload,
@@ -96,11 +97,11 @@ struct NostrEmbeddedBitChat {
        return "bitchat1:" + base64URLEncode(data)
    }

-    private static func normalizeRecipientPeerID(_ recipientPeerID: String) -> String {
-        if let maybeData = Data(hexString: recipientPeerID) {
+    private static func normalizeRecipientPeerID(_ recipientPeerID: PeerID) -> PeerID {
+        if let maybeData = Data(hexString: recipientPeerID.id) {
            if maybeData.count == 32 {
                // Treat as Noise static public key; derive peerID from fingerprint
-                return PeerID(publicKey: maybeData).id
+                return PeerID(publicKey: maybeData)
            } else if maybeData.count == 8 {
                // Already an 8-byte peer ID
                return recipientPeerID
@@ -1,50 +1,5 @@
 import Foundation
-import CryptoKit
 import P256K
-import Security
-
-// Keychain helper for secure storage
-struct KeychainHelper {
-    static func save(key: String, data: Data, service: String, accessible: CFString? = nil) {
-        var query: [String: Any] = [
-            kSecClass as String: kSecClassGenericPassword,
-            kSecAttrService as String: service,
-            kSecAttrAccount as String: key,
-            kSecValueData as String: data
-        ]
-        if let accessible = accessible {
-            query[kSecAttrAccessible as String] = accessible
-        }
-        
-        SecItemDelete(query as CFDictionary)
-        SecItemAdd(query as CFDictionary, nil)
-    }
-    
-    static func load(key: String, service: String) -> Data? {
-        let query: [String: Any] = [
-            kSecClass as String: kSecClassGenericPassword,
-            kSecAttrService as String: service,
-            kSecAttrAccount as String: key,
-            kSecReturnData as String: true
-        ]
-        
-        var result: AnyObject?
-        let status = SecItemCopyMatching(query as CFDictionary, &result)
-        
-        guard status == errSecSuccess else { return nil }
-        return result as? Data
-    }
-    
-    static func delete(key: String, service: String) {
-        let query: [String: Any] = [
-            kSecClass as String: kSecClassGenericPassword,
-            kSecAttrService as String: service,
-            kSecAttrAccount as String: key
-        ]
-        
-        SecItemDelete(query as CFDictionary)
-    }
-}

 /// Manages Nostr identity (secp256k1 keypair) for NIP-17 private messaging
 struct NostrIdentity: Codable {
@@ -103,266 +58,3 @@ struct NostrIdentity: Codable {
        return publicKey.hexEncodedString()
    }
 }
-
-/// Bridge between Noise and Nostr identities
-struct NostrIdentityBridge {
-    private static let keychainService = "chat.bitchat.nostr"
-    private static let currentIdentityKey = "nostr-current-identity"
-    private static let deviceSeedKey = "nostr-device-seed"
-    // In-memory cache to avoid transient keychain access issues
-    private static var deviceSeedCache: Data?
-    
-    /// Get or create the current Nostr identity
-    static func getCurrentNostrIdentity() throws -> NostrIdentity? {
-        // Check if we already have a Nostr identity
-        if let existingData = KeychainHelper.load(key: currentIdentityKey, service: keychainService),
-           let identity = try? JSONDecoder().decode(NostrIdentity.self, from: existingData) {
-            return identity
-        }
-        
-        // Generate new Nostr identity
-        let nostrIdentity = try NostrIdentity.generate()
-        
-        // Store it
-        let data = try JSONEncoder().encode(nostrIdentity)
-        KeychainHelper.save(key: currentIdentityKey, data: data, service: keychainService)
-        
-        return nostrIdentity
-    }
-    
-    /// Associate a Nostr identity with a Noise public key (for favorites)
-    static func associateNostrIdentity(_ nostrPubkey: String, with noisePublicKey: Data) {
-        let key = "nostr-noise-\(noisePublicKey.base64EncodedString())"
-        if let data = nostrPubkey.data(using: .utf8) {
-            KeychainHelper.save(key: key, data: data, service: keychainService)
-        }
-    }
-    
-    /// Get Nostr public key associated with a Noise public key
-    static func getNostrPublicKey(for noisePublicKey: Data) -> String? {
-        let key = "nostr-noise-\(noisePublicKey.base64EncodedString())"
-        guard let data = KeychainHelper.load(key: key, service: keychainService),
-              let pubkey = String(data: data, encoding: .utf8) else {
-            return nil
-        }
-        return pubkey
-    }
-    
-    /// Clear all Nostr identity associations and current identity
-    static func clearAllAssociations() {
-        let query: [String: Any] = [
-            kSecClass as String: kSecClassGenericPassword,
-            kSecAttrService as String: keychainService,
-            kSecMatchLimit as String: kSecMatchLimitAll,
-            kSecReturnAttributes as String: true
-        ]
-
-        var result: AnyObject?
-        let status = SecItemCopyMatching(query as CFDictionary, &result)
-        if status == errSecSuccess, let items = result as? [[String: Any]] {
-            for item in items {
-                var deleteQuery: [String: Any] = [
-                    kSecClass as String: kSecClassGenericPassword,
-                    kSecAttrService as String: keychainService
-                ]
-                if let account = item[kSecAttrAccount as String] as? String {
-                    deleteQuery[kSecAttrAccount as String] = account
-                }
-                SecItemDelete(deleteQuery as CFDictionary)
-            }
-        } else if status == errSecItemNotFound {
-            // nothing persisted; no action needed
-        }
-
-        deviceSeedCache = nil
-    }
-
-    // MARK: - Per-Geohash Identities (Location Channels)
-
-    /// Returns a stable device seed used to derive unlinkable per-geohash identities.
-    /// Stored only on device keychain.
-    private static func getOrCreateDeviceSeed() -> Data {
-        if let cached = deviceSeedCache { return cached }
-        if let existing = KeychainHelper.load(key: deviceSeedKey, service: keychainService) {
-            // Migrate to AfterFirstUnlockThisDeviceOnly for stability during lock
-            KeychainHelper.save(key: deviceSeedKey, data: existing, service: keychainService, accessible: kSecAttrAccessibleAfterFirstUnlockThisDeviceOnly)
-            deviceSeedCache = existing
-            return existing
-        }
-        var seed = Data(count: 32)
-        _ = seed.withUnsafeMutableBytes { ptr in
-            SecRandomCopyBytes(kSecRandomDefault, 32, ptr.baseAddress!)
-        }
-        // Ensure availability after first unlock to prevent unintended rotation when locked
-        KeychainHelper.save(key: deviceSeedKey, data: seed, service: keychainService, accessible: kSecAttrAccessibleAfterFirstUnlockThisDeviceOnly)
-        deviceSeedCache = seed
-        return seed
-    }
-
-    /// Derive a deterministic, unlinkable Nostr identity for a given geohash.
-    /// Uses HMAC-SHA256(deviceSeed, geohash) as private key material, with fallback rehashing
-    /// if the candidate is not a valid secp256k1 private key.
-    static func deriveIdentity(forGeohash geohash: String) throws -> NostrIdentity {
-        let seed = getOrCreateDeviceSeed()
-        guard let msg = geohash.data(using: .utf8) else {
-            throw NSError(domain: "NostrIdentity", code: -1, userInfo: [NSLocalizedDescriptionKey: "Invalid geohash string"])
-        }
-
-        func candidateKey(iteration: UInt32) -> Data {
-            var input = Data(msg)
-            var iterBE = iteration.bigEndian
-            withUnsafeBytes(of: &iterBE) { bytes in
-                input.append(contentsOf: bytes)
-            }
-            let code = CryptoKit.HMAC<CryptoKit.SHA256>.authenticationCode(for: input, using: SymmetricKey(data: seed))
-            return Data(code)
-        }
-
-        // Try a few iterations to ensure a valid key can be formed
-        for i in 0..<10 {
-            let keyData = candidateKey(iteration: UInt32(i))
-            if let identity = try? NostrIdentity(privateKeyData: keyData) {
-                return identity
-            }
-        }
-        // As a final fallback, hash the seed+msg and try again
-        let fallback = (seed + msg).sha256Hash()
-        return try NostrIdentity(privateKeyData: fallback)
-    }
-}
-
-// Bech32 encoding for Nostr (minimal implementation)
-enum Bech32 {
-    private static let charset = "qpzry9x8gf2tvdw0s3jn54khce6mua7l"
-    private static let generator = [0x3b6a57b2, 0x26508e6d, 0x1ea119fa, 0x3d4233dd, 0x2a1462b3]
-    
-    static func encode(hrp: String, data: Data) throws -> String {
-        let values = convertBits(from: 8, to: 5, pad: true, data: Array(data))
-        let checksum = createChecksum(hrp: hrp, values: values)
-        let combined = values + checksum
-        
-        return hrp + "1" + combined.map { 
-            let index = charset.index(charset.startIndex, offsetBy: Int($0))
-            return String(charset[index])
-        }.joined()
-    }
-    
-    static func decode(_ bech32String: String) throws -> (hrp: String, data: Data) {
-        // Find the last occurrence of '1'
-        guard let separatorIndex = bech32String.lastIndex(of: "1") else {
-            throw Bech32Error.invalidFormat
-        }
-        
-        let hrp = String(bech32String[..<separatorIndex])
-        
-        // Validate HRP contains only ASCII characters
-        for char in hrp {
-            guard char.asciiValue != nil else {
-                throw Bech32Error.invalidCharacter
-            }
-        }
-        
-        let dataString = String(bech32String[bech32String.index(after: separatorIndex)...])
-        
-        // Convert characters to values
-        var values = [UInt8]()
-        for char in dataString {
-            guard let index = charset.firstIndex(of: char) else {
-                throw Bech32Error.invalidCharacter
-            }
-            values.append(UInt8(charset.distance(from: charset.startIndex, to: index)))
-        }
-        
-        // Verify checksum
-        guard values.count >= 6 else {
-            throw Bech32Error.invalidChecksum
-        }
-        
-        let payloadValues = Array(values.dropLast(6))
-        let checksum = Array(values.suffix(6))
-        let expectedChecksum = createChecksum(hrp: hrp, values: payloadValues)
-        
-        guard checksum == expectedChecksum else {
-            throw Bech32Error.invalidChecksum
-        }
-        
-        // Convert back to bytes
-        let bytes = convertBits(from: 5, to: 8, pad: false, data: payloadValues)
-        return (hrp: hrp, data: Data(bytes))
-    }
-    
-    enum Bech32Error: Error {
-        case invalidFormat
-        case invalidCharacter
-        case invalidChecksum
-    }
-    
-    private static func convertBits(from: Int, to: Int, pad: Bool, data: [UInt8]) -> [UInt8] {
-        var acc = 0
-        var bits = 0
-        var result = [UInt8]()
-        let maxv = (1 << to) - 1
-        
-        for value in data {
-            acc = (acc << from) | Int(value)
-            bits += from
-            
-            while bits >= to {
-                bits -= to
-                result.append(UInt8((acc >> bits) & maxv))
-            }
-        }
-        
-        if pad && bits > 0 {
-            result.append(UInt8((acc << (to - bits)) & maxv))
-        }
-        
-        return result
-    }
-    
-    private static func createChecksum(hrp: String, values: [UInt8]) -> [UInt8] {
-        let checksumValues = hrpExpand(hrp) + values + [0, 0, 0, 0, 0, 0]
-        let polymod = polymod(checksumValues) ^ 1
-        var checksum = [UInt8]()
-        
-        for i in 0..<6 {
-            checksum.append(UInt8((polymod >> (5 * (5 - i))) & 31))
-        }
-        
-        return checksum
-    }
-    
-    private static func hrpExpand(_ hrp: String) -> [UInt8] {
-        var result = [UInt8]()
-        for c in hrp {
-            guard let asciiValue = c.asciiValue else {
-                return [] // Return empty array for invalid input
-            }
-            result.append(UInt8(asciiValue >> 5))
-        }
-        result.append(0)
-        for c in hrp {
-            guard let asciiValue = c.asciiValue else {
-                return [] // Return empty array for invalid input
-            }
-            result.append(UInt8(asciiValue & 31))
-        }
-        return result
-    }
-    
-    private static func polymod(_ values: [UInt8]) -> Int {
-        var chk = 1
-        for value in values {
-            let b = chk >> 25
-            chk = (chk & 0x1ffffff) << 5 ^ Int(value)
-            for i in 0..<5 {
-                if (b >> i) & 1 == 1 {
-                    chk ^= generator[i]
-                }
-            }
-        }
-        return chk
-    }
-}
-
-// Data hex encoding extension moved to BinaryEncodingUtils.swift to avoid duplication
@@ -0,0 +1,157 @@
+import Foundation
+import CryptoKit
+
+/// Bridge between Noise and Nostr identities
+final class NostrIdentityBridge {
+    private let keychainService = "chat.bitchat.nostr"
+    private let currentIdentityKey = "nostr-current-identity"
+    private let deviceSeedKey = "nostr-device-seed"
+    // In-memory cache to avoid transient keychain access issues
+    private var deviceSeedCache: Data?
+    // Cache derived identities to avoid repeated crypto during view rendering
+    private var derivedIdentityCache: [String: NostrIdentity] = [:]
+    private let cacheLock = NSLock()
+
+    private let keychain: KeychainManagerProtocol
+
+    init(keychain: KeychainManagerProtocol = KeychainManager()) {
+        self.keychain = keychain
+    }
+    
+    /// Get or create the current Nostr identity
+    func getCurrentNostrIdentity() throws -> NostrIdentity? {
+        // Check if we already have a Nostr identity
+        if let existingData = keychain.load(key: currentIdentityKey, service: keychainService),
+           let identity = try? JSONDecoder().decode(NostrIdentity.self, from: existingData) {
+            return identity
+        }
+        
+        // Generate new Nostr identity
+        let nostrIdentity = try NostrIdentity.generate()
+        
+        // Store it
+        let data = try JSONEncoder().encode(nostrIdentity)
+        keychain.save(key: currentIdentityKey, data: data, service: keychainService, accessible: nil)
+        
+        return nostrIdentity
+    }
+    
+    /// Associate a Nostr identity with a Noise public key (for favorites)
+    func associateNostrIdentity(_ nostrPubkey: String, with noisePublicKey: Data) {
+        let key = "nostr-noise-\(noisePublicKey.base64EncodedString())"
+        if let data = nostrPubkey.data(using: .utf8) {
+            keychain.save(key: key, data: data, service: keychainService, accessible: nil)
+        }
+    }
+    
+    /// Get Nostr public key associated with a Noise public key
+    func getNostrPublicKey(for noisePublicKey: Data) -> String? {
+        let key = "nostr-noise-\(noisePublicKey.base64EncodedString())"
+        guard let data = keychain.load(key: key, service: keychainService),
+              let pubkey = String(data: data, encoding: .utf8) else {
+            return nil
+        }
+        return pubkey
+    }
+    
+    /// Clear all Nostr identity associations and current identity
+    func clearAllAssociations() {
+        let query: [String: Any] = [
+            kSecClass as String: kSecClassGenericPassword,
+            kSecAttrService as String: keychainService,
+            kSecMatchLimit as String: kSecMatchLimitAll,
+            kSecReturnAttributes as String: true
+        ]
+
+        var result: AnyObject?
+        let status = SecItemCopyMatching(query as CFDictionary, &result)
+        if status == errSecSuccess, let items = result as? [[String: Any]] {
+            for item in items {
+                var deleteQuery: [String: Any] = [
+                    kSecClass as String: kSecClassGenericPassword,
+                    kSecAttrService as String: keychainService
+                ]
+                if let account = item[kSecAttrAccount as String] as? String {
+                    deleteQuery[kSecAttrAccount as String] = account
+                }
+                SecItemDelete(deleteQuery as CFDictionary)
+            }
+        } else if status == errSecItemNotFound {
+            // nothing persisted; no action needed
+        }
+
+        deviceSeedCache = nil
+    }
+
+    // MARK: - Per-Geohash Identities (Location Channels)
+
+    /// Returns a stable device seed used to derive unlinkable per-geohash identities.
+    /// Stored only on device keychain.
+    private func getOrCreateDeviceSeed() -> Data {
+        if let cached = deviceSeedCache { return cached }
+        if let existing = keychain.load(key: deviceSeedKey, service: keychainService) {
+            // Migrate to AfterFirstUnlockThisDeviceOnly for stability during lock
+            keychain.save(key: deviceSeedKey, data: existing, service: keychainService, accessible: kSecAttrAccessibleAfterFirstUnlockThisDeviceOnly)
+            deviceSeedCache = existing
+            return existing
+        }
+        var seed = Data(count: 32)
+        _ = seed.withUnsafeMutableBytes { ptr in
+            SecRandomCopyBytes(kSecRandomDefault, 32, ptr.baseAddress!)
+        }
+        // Ensure availability after first unlock to prevent unintended rotation when locked
+        keychain.save(key: deviceSeedKey, data: seed, service: keychainService, accessible: kSecAttrAccessibleAfterFirstUnlockThisDeviceOnly)
+        deviceSeedCache = seed
+        return seed
+    }
+
+    /// Derive a deterministic, unlinkable Nostr identity for a given geohash.
+    /// Uses HMAC-SHA256(deviceSeed, geohash) as private key material, with fallback rehashing
+    /// if the candidate is not a valid secp256k1 private key.
+    func deriveIdentity(forGeohash geohash: String) throws -> NostrIdentity {
+        // Check cache first to avoid repeated crypto + keychain I/O during view rendering
+        cacheLock.lock()
+        if let cached = derivedIdentityCache[geohash] {
+            cacheLock.unlock()
+            return cached
+        }
+        cacheLock.unlock()
+
+        let seed = getOrCreateDeviceSeed()
+        guard let msg = geohash.data(using: .utf8) else {
+            throw NSError(domain: "NostrIdentity", code: -1, userInfo: [NSLocalizedDescriptionKey: "Invalid geohash string"])
+        }
+
+        func candidateKey(iteration: UInt32) -> Data {
+            var input = Data(msg)
+            var iterBE = iteration.bigEndian
+            withUnsafeBytes(of: &iterBE) { bytes in
+                input.append(contentsOf: bytes)
+            }
+            let code = HMAC<SHA256>.authenticationCode(for: input, using: SymmetricKey(data: seed))
+            return Data(code)
+        }
+
+        // Try a few iterations to ensure a valid key can be formed
+        for i in 0..<10 {
+            let keyData = candidateKey(iteration: UInt32(i))
+            if let identity = try? NostrIdentity(privateKeyData: keyData) {
+                // Cache the result
+                cacheLock.lock()
+                derivedIdentityCache[geohash] = identity
+                cacheLock.unlock()
+                return identity
+            }
+        }
+        // As a final fallback, hash the seed+msg and try again
+        let fallback = (seed + msg).sha256Hash()
+        let identity = try NostrIdentity(privateKeyData: fallback)
+
+        // Cache the result
+        cacheLock.lock()
+        derivedIdentityCache[geohash] = identity
+        cacheLock.unlock()
+
+        return identity
+    }
+}
@@ -18,6 +18,7 @@ struct NostrProtocol {
        case seal = 13 // NIP-17 sealed event
        case giftWrap = 1059 // NIP-59 gift wrap
        case ephemeralEvent = 20000
+        case geohashPresence = 20001
    }
    
    /// Create a NIP-17 private message
@@ -108,7 +109,7 @@ struct NostrProtocol {
        teleported: Bool = false
    ) throws -> NostrEvent {
        var tags = [["g", geohash]]
-        if let nickname = nickname?.trimmingCharacters(in: .whitespacesAndNewlines), !nickname.isEmpty {
+        if let nickname = nickname?.trimmedOrNilIfEmpty {
            tags.append(["n", nickname])
        }
        if teleported {
@@ -125,6 +126,24 @@ struct NostrProtocol {
        return try event.sign(with: schnorrKey)
    }

+    /// Create a geohash presence heartbeat (kind 20001)
+    /// Must contain empty content and NO nickname tag
+    static func createGeohashPresenceEvent(
+        geohash: String,
+        senderIdentity: NostrIdentity
+    ) throws -> NostrEvent {
+        let tags = [["g", geohash]]
+        let event = NostrEvent(
+            pubkey: senderIdentity.publicKeyHex,
+            createdAt: Date(),
+            kind: .geohashPresence,
+            tags: tags,
+            content: ""
+        )
+        let schnorrKey = try senderIdentity.schnorrSigningKey()
+        return try event.sign(with: schnorrKey)
+    }
+
    /// Create a persistent location note (kind 1: text note) tagged to a street-level geohash.
    static func createGeohashTextNote(
        content: String,
@@ -133,7 +152,7 @@ struct NostrProtocol {
        nickname: String? = nil
    ) throws -> NostrEvent {
        var tags = [["g", geohash]]
-        if let nickname = nickname?.trimmingCharacters(in: .whitespacesAndNewlines), !nickname.isEmpty {
+        if let nickname = nickname?.trimmedOrNilIfEmpty {
            tags.append(["n", nickname])
        }
        let event = NostrEvent(
@@ -509,6 +528,26 @@ struct NostrEvent: Codable {
        signed.sig = signatureHex
        return signed
    }
+
+    /// Validate that the event ID and Schnorr signature match the content and pubkey.
+    /// Returns false when the signature is missing, malformed, or does not verify.
+    func isValidSignature() -> Bool {
+        guard let sig = sig,
+              let sigData = Data(hexString: sig),
+              let pubData = Data(hexString: pubkey),
+              sigData.count == 64,
+              pubData.count == 32,
+              let signature = try? P256K.Schnorr.SchnorrSignature(dataRepresentation: sigData),
+              let (expectedId, eventHash) = try? calculateEventId(),
+              expectedId == id
+        else {
+            return false
+        }
+
+        var messageBytes = [UInt8](eventHash)
+        let xonly = P256K.Schnorr.XonlyKey(dataRepresentation: pubData)
+        return xonly.isValid(signature, for: &messageBytes)
+    }
    
    private func calculateEventId() throws -> (String, Data) {
        let serialized = [
@@ -4,6 +4,100 @@ import Network
 import Combine
 import Tor

+protocol NostrRelayConnectionProtocol: AnyObject {
+    func resume()
+    func cancel(with closeCode: URLSessionWebSocketTask.CloseCode, reason: Data?)
+    func send(_ message: URLSessionWebSocketTask.Message, completionHandler: @escaping (Error?) -> Void)
+    func receive(completionHandler: @escaping (Result<URLSessionWebSocketTask.Message, Error>) -> Void)
+    func sendPing(pongReceiveHandler: @escaping (Error?) -> Void)
+}
+
+protocol NostrRelaySessionProtocol {
+    func webSocketTask(with url: URL) -> NostrRelayConnectionProtocol
+}
+
+private final class URLSessionWebSocketTaskAdapter: NostrRelayConnectionProtocol {
+    private let base: URLSessionWebSocketTask
+
+    init(base: URLSessionWebSocketTask) {
+        self.base = base
+    }
+
+    func resume() {
+        base.resume()
+    }
+
+    func cancel(with closeCode: URLSessionWebSocketTask.CloseCode, reason: Data?) {
+        base.cancel(with: closeCode, reason: reason)
+    }
+
+    func send(_ message: URLSessionWebSocketTask.Message, completionHandler: @escaping (Error?) -> Void) {
+        base.send(message, completionHandler: completionHandler)
+    }
+
+    func receive(completionHandler: @escaping (Result<URLSessionWebSocketTask.Message, Error>) -> Void) {
+        base.receive(completionHandler: completionHandler)
+    }
+
+    func sendPing(pongReceiveHandler: @escaping (Error?) -> Void) {
+        base.sendPing(pongReceiveHandler: pongReceiveHandler)
+    }
+}
+
+private struct URLSessionAdapter: NostrRelaySessionProtocol {
+    let base: URLSession
+
+    func webSocketTask(with url: URL) -> NostrRelayConnectionProtocol {
+        URLSessionWebSocketTaskAdapter(base: base.webSocketTask(with: url))
+    }
+}
+
+struct NostrRelayManagerDependencies {
+    var activationAllowed: () -> Bool
+    var userTorEnabled: () -> Bool
+    var hasMutualFavorites: () -> Bool
+    var hasLocationPermission: () -> Bool
+    var mutualFavoritesPublisher: AnyPublisher<Set<Data>, Never>
+    var locationPermissionPublisher: AnyPublisher<LocationChannelManager.PermissionState, Never>
+    var torEnforced: () -> Bool
+    var torIsReady: () -> Bool
+    var torIsForeground: () -> Bool
+    var awaitTorReady: (@escaping (Bool) -> Void) -> Void
+    var makeSession: () -> NostrRelaySessionProtocol
+    var scheduleAfter: @Sendable (TimeInterval, @escaping @Sendable () -> Void) -> Void
+    var now: () -> Date
+}
+
+private extension NostrRelayManagerDependencies {
+    @MainActor
+    static func live() -> Self {
+        Self(
+            activationAllowed: { NetworkActivationService.shared.activationAllowed },
+            userTorEnabled: { NetworkActivationService.shared.userTorEnabled },
+            hasMutualFavorites: { !FavoritesPersistenceService.shared.mutualFavorites.isEmpty },
+            hasLocationPermission: { LocationChannelManager.shared.permissionState == .authorized },
+            mutualFavoritesPublisher: FavoritesPersistenceService.shared.$mutualFavorites.eraseToAnyPublisher(),
+            locationPermissionPublisher: LocationChannelManager.shared.$permissionState.eraseToAnyPublisher(),
+            torEnforced: { TorManager.shared.torEnforced },
+            torIsReady: { TorManager.shared.isReady },
+            torIsForeground: { TorManager.shared.isForeground() },
+            awaitTorReady: { completion in
+                Task.detached {
+                    let ready = await TorManager.shared.awaitReady()
+                    await MainActor.run {
+                        completion(ready)
+                    }
+                }
+            },
+            makeSession: { URLSessionAdapter(base: TorURLSession.shared.session) },
+            scheduleAfter: { delay, action in
+                DispatchQueue.main.asyncAfter(deadline: .now() + delay, execute: action)
+            },
+            now: Date.init
+        )
+    }
+}
+
 /// Manages WebSocket connections to Nostr relays
@MainActor
 final class NostrRelayManager: ObservableObject {
@@ -41,10 +135,11 @@ final class NostrRelayManager: ObservableObject {
    @Published private(set) var relays: [Relay] = []
    @Published private(set) var isConnected = false
    
+    private let dependencies: NostrRelayManagerDependencies
    private var allowDefaultRelays: Bool = false
    private var hasMutualFavorites: Bool = false
    private var hasLocationPermission: Bool = false
-    private var connections: [String: URLSessionWebSocketTask] = [:]
+    private var connections: [String: NostrRelayConnectionProtocol] = [:]
    private var subscriptions: [String: Set<String>] = [:] // relay URL -> active subscription IDs
    private var pendingSubscriptions: [String: [String: String]] = [:] // relay URL -> (subscription id -> encoded REQ JSON)
    private var messageHandlers: [String: (NostrEvent) -> Void] = [:]
@@ -69,9 +164,7 @@ final class NostrRelayManager: ObservableObject {
    private var messageQueue: [PendingSend] = []
    private let messageQueueLock = NSLock()
    private let encoder = JSONEncoder()
-    private let decoder = JSONDecoder()
-    private var networkService: NetworkActivationService { NetworkActivationService.shared }
-    private var shouldUseTor: Bool { networkService.userTorEnabled }
+    private var shouldUseTor: Bool { dependencies.userTorEnabled() }
    
    // Exponential backoff configuration
    private let initialBackoffInterval: TimeInterval = TransportConfig.nostrRelayInitialBackoffSeconds
@@ -79,18 +172,17 @@ final class NostrRelayManager: ObservableObject {
    private let backoffMultiplier: Double = TransportConfig.nostrRelayBackoffMultiplier
    private let maxReconnectAttempts = TransportConfig.nostrRelayMaxReconnectAttempts
    
-    // Reconnection timer
-    private var reconnectionTimer: Timer?
    // Bump generation to invalidate scheduled reconnects when we reset/disconnect
    private var connectionGeneration: Int = 0
    
    init() {
-        hasMutualFavorites = !FavoritesPersistenceService.shared.mutualFavorites.isEmpty
-        hasLocationPermission = LocationChannelManager.shared.permissionState == .authorized
+        self.dependencies = .live()
+        hasMutualFavorites = dependencies.hasMutualFavorites()
+        hasLocationPermission = dependencies.hasLocationPermission()
        applyDefaultRelayPolicy(force: true)
        // Deterministic JSON shape for outbound requests
        self.encoder.outputFormatting = .sortedKeys
-        FavoritesPersistenceService.shared.$mutualFavorites
+        dependencies.mutualFavoritesPublisher
            .receive(on: DispatchQueue.main)
            .sink { [weak self] favorites in
                guard let self = self else { return }
@@ -98,7 +190,34 @@ final class NostrRelayManager: ObservableObject {
                self.applyDefaultRelayPolicy()
            }
            .store(in: &cancellables)
-        LocationChannelManager.shared.$permissionState
+        dependencies.locationPermissionPublisher
+            .receive(on: DispatchQueue.main)
+            .sink { [weak self] state in
+                guard let self = self else { return }
+                let authorized = (state == .authorized)
+                if authorized == self.hasLocationPermission { return }
+                self.hasLocationPermission = authorized
+                self.applyDefaultRelayPolicy()
+            }
+            .store(in: &cancellables)
+    }
+
+    internal init(dependencies: NostrRelayManagerDependencies) {
+        self.dependencies = dependencies
+        hasMutualFavorites = dependencies.hasMutualFavorites()
+        hasLocationPermission = dependencies.hasLocationPermission()
+        applyDefaultRelayPolicy(force: true)
+        // Deterministic JSON shape for outbound requests
+        self.encoder.outputFormatting = .sortedKeys
+        dependencies.mutualFavoritesPublisher
+            .receive(on: DispatchQueue.main)
+            .sink { [weak self] favorites in
+                guard let self = self else { return }
+                self.hasMutualFavorites = !favorites.isEmpty
+                self.applyDefaultRelayPolicy()
+            }
+            .store(in: &cancellables)
+        dependencies.locationPermissionPublisher
            .receive(on: DispatchQueue.main)
            .sink { [weak self] state in
                guard let self = self else { return }
@@ -113,20 +232,18 @@ final class NostrRelayManager: ObservableObject {
    /// Connect to all configured relays
    func connect() {
        // Global network policy gate
-        guard networkService.activationAllowed else { return }
+        guard dependencies.activationAllowed() else { return }
        if shouldUseTor {
            // Ensure Tor is started early and wait for readiness off-main; then hop back to connect.
-            Task.detached {
-                let ready = await TorManager.shared.awaitReady()
-                await MainActor.run {
-                    if !ready {
-                        SecureLogger.error("❌ Tor not ready; aborting relay connections (fail-closed)", category: .session)
-                        return
-                    }
-                    SecureLogger.debug("🌐 Connecting to \(self.relays.count) Nostr relays (via Tor)", category: .session)
-                    for relay in self.relays {
-                        self.connectToRelay(relay.url)
-                    }
+            dependencies.awaitTorReady { [weak self] ready in
+                guard let self = self else { return }
+                if !ready {
+                    SecureLogger.error("❌ Tor not ready; aborting relay connections (fail-closed)", category: .session)
+                    return
+                }
+                SecureLogger.debug("🌐 Connecting to \(self.relays.count) Nostr relays (via Tor)", category: .session)
+                for relay in self.relays {
+                    self.connectToRelay(relay.url)
                }
            }
        } else {
@@ -153,15 +270,14 @@ final class NostrRelayManager: ObservableObject {
    /// Ensure connections exist to the given relay URLs (idempotent).
    func ensureConnections(to relayUrls: [String]) {
        // Global network policy gate
-        guard networkService.activationAllowed else { return }
+        guard dependencies.activationAllowed() else { return }
        let targets = allowedRelayList(from: relayUrls)
        guard !targets.isEmpty else { return }
-        if shouldUseTor && TorManager.shared.torEnforced && !TorManager.shared.isReady {
+        if shouldUseTor && dependencies.torEnforced() && !dependencies.torIsReady() {
            // Defer until Tor is fully ready; avoid queuing connection attempts early
-            Task.detached { [weak self] in
+            dependencies.awaitTorReady { [weak self] ready in
                guard let self = self else { return }
-                let ready = await TorManager.shared.awaitReady()
-                await MainActor.run { if ready { self.ensureConnections(to: relayUrls) } }
+                if ready { self.ensureConnections(to: relayUrls) }
            }
            return
        }
@@ -178,13 +294,12 @@ final class NostrRelayManager: ObservableObject {
    /// Send an event to specified relays (or all if none specified)
    func sendEvent(_ event: NostrEvent, to relayUrls: [String]? = nil) {
        // Global network policy gate
-        guard networkService.activationAllowed else { return }
-        if shouldUseTor && TorManager.shared.torEnforced && !TorManager.shared.isReady {
+        guard dependencies.activationAllowed() else { return }
+        if shouldUseTor && dependencies.torEnforced() && !dependencies.torIsReady() {
            // Defer sends until Tor is ready to avoid premature queueing
-            Task.detached { [weak self] in
+            dependencies.awaitTorReady { [weak self] ready in
                guard let self = self else { return }
-                let ready = await TorManager.shared.awaitReady()
-                await MainActor.run { if ready { self.sendEvent(event, to: relayUrls) } }
+                if ready { self.sendEvent(event, to: relayUrls) }
            }
            return
        }
@@ -256,24 +371,21 @@ final class NostrRelayManager: ObservableObject {
        onEOSE: (() -> Void)? = nil
    ) {
        // Global network policy gate
-        guard networkService.activationAllowed else { return }
+        guard dependencies.activationAllowed() else { return }
        // Coalesce rapid duplicate subscribe requests only if a handler already exists
-        let now = Date()
+        let now = dependencies.now()
        if messageHandlers[id] != nil {
            if let last = subscribeCoalesce[id], now.timeIntervalSince(last) < 1.0 {
                return
            }
        }
        subscribeCoalesce[id] = now
-        if shouldUseTor && TorManager.shared.torEnforced && !TorManager.shared.isReady {
+        if shouldUseTor && dependencies.torEnforced() && !dependencies.torIsReady() {
            // Defer subscription setup until Tor is ready; avoid queuing subs early
-            Task.detached { [weak self] in
+            dependencies.awaitTorReady { [weak self] ready in
                guard let self = self else { return }
-                let ready = await TorManager.shared.awaitReady()
-                await MainActor.run {
-                    if ready {
-                        self.subscribe(filter: filter, id: id, relayUrls: relayUrls, handler: handler)
-                    }
+                if ready {
+                    self.subscribe(filter: filter, id: id, relayUrls: relayUrls, handler: handler, onEOSE: onEOSE)
                }
            }
            return
@@ -300,7 +412,7 @@ final class NostrRelayManager: ObservableObject {
            for url in urls where !existingSet.contains(url) {
                relays.append(Relay(url: url))
            }
-            for url in candidateUrls {
+            for url in urls {
                var map = self.pendingSubscriptions[url] ?? [:]
                map[id] = messageString
                self.pendingSubscriptions[url] = map
@@ -349,7 +461,7 @@ final class NostrRelayManager: ObservableObject {
                relays.append(Relay(url: url))
                existing.insert(url)
            }
-            if networkService.activationAllowed {
+            if dependencies.activationAllowed() {
                ensureConnections(to: Self.defaultRelays)
            }
        } else {
@@ -359,6 +471,7 @@ final class NostrRelayManager: ObservableObject {
                }
                connections.removeValue(forKey: url)
                subscriptions.removeValue(forKey: url)
+                pendingSubscriptions.removeValue(forKey: url)
            }
            messageQueueLock.lock()
            for index in (0..<messageQueue.count).reversed() {
@@ -403,10 +516,9 @@ final class NostrRelayManager: ObservableObject {
        // Send unsubscribe to all relays
        for (relayUrl, connection) in connections {
            if subscriptions[relayUrl]?.contains(id) == true {
+                subscriptions[relayUrl]?.remove(id)
                connection.send(.string(messageString)) { _ in
-                    Task { @MainActor in
-                        self.subscriptions[relayUrl]?.remove(id)
-                    }
+                    // Local state is cleared before sending so callers can re-subscribe immediately.
                }
            }
        }
@@ -416,14 +528,14 @@ final class NostrRelayManager: ObservableObject {
    
    private func connectToRelay(_ urlString: String) {
        // Global network policy gate
-        guard networkService.activationAllowed else { return }
+        guard dependencies.activationAllowed() else { return }
        guard let url = URL(string: urlString) else { 
            SecureLogger.warning("Invalid relay URL: \(urlString)", category: .session)
            return 
        }

        // Avoid initiating connections while app is backgrounded; we'll reconnect on foreground
-        if shouldUseTor && TorManager.shared.torEnforced && !TorManager.shared.isForeground() {
+        if shouldUseTor && dependencies.torEnforced() && !dependencies.torIsForeground() {
            return
        }
        
@@ -438,19 +550,16 @@ final class NostrRelayManager: ObservableObject {
        // Attempting to connect to Nostr relay via the proxied session
        
        // If Tor is enforced but not ready, delay connection until it is.
-        if shouldUseTor && TorManager.shared.torEnforced && !TorManager.shared.isReady {
-            Task.detached { [weak self] in
+        if shouldUseTor && dependencies.torEnforced() && !dependencies.torIsReady() {
+            dependencies.awaitTorReady { [weak self] ready in
                guard let self = self else { return }
-                let ready = await TorManager.shared.awaitReady()
-                await MainActor.run {
-                    if ready { self.connectToRelay(urlString) }
-                    else { SecureLogger.error("❌ Tor not ready; skipping connection to \(urlString)", category: .session) }
-                }
+                if ready { self.connectToRelay(urlString) }
+                else { SecureLogger.error("❌ Tor not ready; skipping connection to \(urlString)", category: .session) }
            }
            return
        }
        
-        let session = TorURLSession.shared.session
+        let session = dependencies.makeSession()
        let task = session.webSocketTask(with: url)
        
        connections[urlString] = task
@@ -498,7 +607,7 @@ final class NostrRelayManager: ObservableObject {
        pendingSubscriptions[relayUrl] = nil
    }
    
-    private func receiveMessage(from task: URLSessionWebSocketTask, relayUrl: String) {
+    private func receiveMessage(from task: NostrRelayConnectionProtocol, relayUrl: String) {
        task.receive { [weak self] result in
            guard let self = self else { return }
            
@@ -508,7 +617,7 @@ final class NostrRelayManager: ObservableObject {
                Task.detached(priority: .utility) {
                    guard let parsed = ParsedInbound(message) else { return }
                    await MainActor.run {
-                        NostrRelayManager.shared.handleParsedMessage(parsed, from: relayUrl)
+                        self.handleParsedMessage(parsed, from: relayUrl)
                    }
                }
                
@@ -572,7 +681,7 @@ final class NostrRelayManager: ObservableObject {
        }
    }
    
-    private func sendToRelay(event: NostrEvent, connection: URLSessionWebSocketTask, relayUrl: String) {
+    private func sendToRelay(event: NostrEvent, connection: NostrRelayConnectionProtocol, relayUrl: String) {
        let req = NostrRequest.event(event)
        
        do {
@@ -604,11 +713,11 @@ final class NostrRelayManager: ObservableObject {
            relays[index].isConnected = isConnected
            relays[index].lastError = error
            if isConnected {
-                relays[index].lastConnectedAt = Date()
+                relays[index].lastConnectedAt = dependencies.now()
                relays[index].reconnectAttempts = 0  // Reset on successful connection
                relays[index].nextReconnectTime = nil
            } else {
-                relays[index].lastDisconnectedAt = Date()
+                relays[index].lastDisconnectedAt = dependencies.now()
            }
        }
        updateConnectionStatus()
@@ -624,7 +733,7 @@ final class NostrRelayManager: ObservableObject {
    
    private func handleDisconnection(relayUrl: String, error: Error) {
        // If networking is disallowed, do not schedule reconnection
-        if !networkService.activationAllowed {
+        if !dependencies.activationAllowed() {
            connections.removeValue(forKey: relayUrl)
            subscriptions.removeValue(forKey: relayUrl)
            updateRelayStatus(relayUrl, isConnected: false, error: error)
@@ -669,19 +778,21 @@ final class NostrRelayManager: ObservableObject {
            maxBackoffInterval
        )
        
-        let nextReconnectTime = Date().addingTimeInterval(backoffInterval)
+        let nextReconnectTime = dependencies.now().addingTimeInterval(backoffInterval)
        relays[index].nextReconnectTime = nextReconnectTime
        
        
        // Schedule reconnection with exponential backoff
        let gen = connectionGeneration
-        DispatchQueue.main.asyncAfter(deadline: .now() + backoffInterval) { [weak self] in
-            guard let self = self else { return }
-            // Ignore stale scheduled reconnects from a previous generation
-            guard gen == self.connectionGeneration else { return }
-            // Check if we should still reconnect (relay might have been removed)
-            if self.relays.contains(where: { $0.url == relayUrl }) {
-                self.connectToRelay(relayUrl)
+        dependencies.scheduleAfter(backoffInterval) { [weak self] in
+            Task { @MainActor [weak self] in
+                guard let self = self else { return }
+                // Ignore stale scheduled reconnects from a previous generation
+                guard gen == self.connectionGeneration else { return }
+                // Check if we should still reconnect (relay might have been removed)
+                if self.relays.contains(where: { $0.url == relayUrl }) {
+                    self.connectToRelay(relayUrl)
+                }
            }
        }
    }
@@ -695,6 +806,7 @@ final class NostrRelayManager: ObservableObject {
        // Reset reconnection attempts
        relays[index].reconnectAttempts = 0
        relays[index].nextReconnectTime = nil
+        relays[index].lastError = nil
        
        // Disconnect if connected
        if let connection = connections[relayUrl] {
@@ -715,6 +827,20 @@ final class NostrRelayManager: ObservableObject {
             nextReconnectTime: relay.nextReconnectTime)
        }
    }
+
+    var debugPendingMessageQueueCount: Int {
+        messageQueueLock.lock()
+        defer { messageQueueLock.unlock() }
+        return messageQueue.count
+    }
+
+    func debugPendingSubscriptionCount(for relayUrl: String) -> Int {
+        pendingSubscriptions[relayUrl]?.count ?? 0
+    }
+
+    func debugFlushMessageQueue() {
+        flushMessageQueue(for: nil)
+    }
    
    /// Reset all relay connections
    func resetAllConnections() {
@@ -767,7 +893,8 @@ private enum ParsedInbound {
            if array.count >= 3,
               let subId = array[1] as? String,
               let eventDict = array[2] as? [String: Any],
-               let event = try? NostrEvent(from: eventDict) {
+               let event = try? NostrEvent(from: eventDict),
+               event.isValidSignature() {
                self = .event(subId: subId, event: event)
                return
            }
@@ -887,10 +1014,10 @@ struct NostrFilter: Encodable {
        return filter
    }

-    // For location channels: geohash-scoped ephemeral events (kind 20000)
-    static func geohashEphemeral(_ geohash: String, since: Date? = nil, limit: Int = 200) -> NostrFilter {
+    // For location channels: geohash-scoped ephemeral events (kind 20000) and presence (kind 20001)
+    static func geohashEphemeral(_ geohash: String, since: Date? = nil, limit: Int = 1000) -> NostrFilter {
        var filter = NostrFilter()
-        filter.kinds = [20000]
+        filter.kinds = [20000, 20001]
        filter.since = since?.timeIntervalSince1970.toInt()
        filter.tagFilters = ["g": [geohash]]
        filter.limit = limit
@@ -906,6 +1033,16 @@ struct NostrFilter: Encodable {
        filter.limit = limit
        return filter
    }
+
+    // For location notes with neighbors: subscribe to multiple geohashes (center + neighbors)
+    static func geohashNotes(_ geohashes: [String], since: Date? = nil, limit: Int = 200) -> NostrFilter {
+        var filter = NostrFilter()
+        filter.kinds = [1]
+        filter.since = since?.timeIntervalSince1970.toInt()
+        filter.tagFilters = ["g": geohashes]
+        filter.limit = limit
+        return filter
+    }
 }

 // Dynamic coding key for tag filters
@@ -5,16 +5,27 @@ import CryptoKit
 /// Implements HChaCha20 to derive a subkey and reduces the 24-byte nonce to a 12-byte nonce
 /// as per XChaCha20 construction.
 enum XChaCha20Poly1305Compat {
+
+    /// Errors that can occur during XChaCha20-Poly1305 operations
+    enum Error: Swift.Error {
+        case invalidKeyLength(expected: Int, got: Int)
+        case invalidNonceLength(expected: Int, got: Int)
+    }
+
    struct SealBox {
        let ciphertext: Data
        let tag: Data
    }

    static func seal(plaintext: Data, key: Data, nonce24: Data, aad: Data? = nil) throws -> SealBox {
-        precondition(key.count == 32, "XChaCha20 key must be 32 bytes")
-        precondition(nonce24.count == 24, "XChaCha20 nonce must be 24 bytes")
+        guard key.count == 32 else {
+            throw Error.invalidKeyLength(expected: 32, got: key.count)
+        }
+        guard nonce24.count == 24 else {
+            throw Error.invalidNonceLength(expected: 24, got: nonce24.count)
+        }

-        let subkey = hchacha20(key: key, nonce16: nonce24.prefix(16))
+        let subkey = try hchacha20(key: key, nonce16: Data(nonce24.prefix(16)))
        let nonce12 = derive12ByteNonce(from24: nonce24)
        let chachaKey = SymmetricKey(data: subkey)
        let nonce = try ChaChaPoly.Nonce(data: nonce12)
@@ -23,10 +34,14 @@ enum XChaCha20Poly1305Compat {
    }

    static func open(ciphertext: Data, tag: Data, key: Data, nonce24: Data, aad: Data? = nil) throws -> Data {
-        precondition(key.count == 32, "XChaCha20 key must be 32 bytes")
-        precondition(nonce24.count == 24, "XChaCha20 nonce must be 24 bytes")
+        guard key.count == 32 else {
+            throw Error.invalidKeyLength(expected: 32, got: key.count)
+        }
+        guard nonce24.count == 24 else {
+            throw Error.invalidNonceLength(expected: 24, got: nonce24.count)
+        }

-        let subkey = hchacha20(key: key, nonce16: nonce24.prefix(16))
+        let subkey = try hchacha20(key: key, nonce16: Data(nonce24.prefix(16)))
        let nonce12 = derive12ByteNonce(from24: nonce24)
        let chachaKey = SymmetricKey(data: subkey)
        let box = try ChaChaPoly.SealedBox(nonce: ChaChaPoly.Nonce(data: nonce12), ciphertext: ciphertext, tag: tag)
@@ -43,10 +58,14 @@ enum XChaCha20Poly1305Compat {
        return out
    }

-    private static func hchacha20(key: Data, nonce16: Data) -> Data {
+    private static func hchacha20(key: Data, nonce16: Data) throws -> Data {
        // HChaCha20 based on the original ChaCha20 core with a 16-byte nonce.
-        precondition(key.count == 32)
-        precondition(nonce16.count == 16)
+        guard key.count == 32 else {
+            throw Error.invalidKeyLength(expected: 32, got: key.count)
+        }
+        guard nonce16.count == 16 else {
+            throw Error.invalidNonceLength(expected: 16, got: nonce16.count)
+        }

        // Constants "expand 32-byte k"
        var state: [UInt32] = [
@@ -6,34 +6,7 @@
 //

 import Foundation
-
-// MARK: - Hex Encoding/Decoding
-
-extension Data {
-    func hexEncodedString() -> String {
-        if self.isEmpty {
-            return ""
-        }
-        return self.map { String(format: "%02x", $0) }.joined()
-    }
-    
-    init?(hexString: String) {
-        let len = hexString.count / 2
-        var data = Data(capacity: len)
-        var index = hexString.startIndex
-        
-        for _ in 0..<len {
-            let nextIndex = hexString.index(index, offsetBy: 2)
-            guard let byte = UInt8(String(hexString[index..<nextIndex]), radix: 16) else {
-                return nil
-            }
-            data.append(byte)
-            index = nextIndex
-        }
-        
-        self = data
-    }
-}
+import BitFoundation

 // MARK: - Binary Encoding Utilities

@@ -22,11 +22,11 @@
 ///
 /// ## Wire Format
 /// ```
-/// Header (Fixed 13 bytes):
-/// +--------+------+-----+-----------+-------+----------------+
-/// |Version | Type | TTL | Timestamp | Flags | PayloadLength  |
-/// |1 byte  |1 byte|1byte| 8 bytes   | 1 byte| 2 bytes        |
-/// +--------+------+-----+-----------+-------+----------------+
+/// Header (Fixed 14 bytes for v1, 16 bytes for v2):
+/// +--------+------+-----+-----------+-------+------------------+
+/// |Version | Type | TTL | Timestamp | Flags | PayloadLength    |
+/// |1 byte  |1 byte|1byte| 8 bytes   | 1 byte| 2 or 4 bytes     |
+/// +--------+------+-----+-----------+-------+------------------+
 ///
 /// Variable sections:
 /// +----------+-------------+---------+------------+
@@ -52,7 +52,7 @@
 /// ## Flag Bits
 /// - Bit 0: Has recipient ID (directed message)
 /// - Bit 1: Has signature (authenticated message)
-/// - Bit 2: Is compressed (LZ4 compression applied)
+/// - Bit 2: Is compressed (zlib compression applied)
 /// - Bits 3-7: Reserved for future use
 ///
 /// ## Size Constraints
@@ -89,6 +89,7 @@
 ///

 import Foundation
+import BitLogger

 extension Data {
    func trimmingNullBytes() -> Data {
@@ -105,83 +106,125 @@ extension Data {
 /// their binary wire format representation.
 /// - Note: All multi-byte values use network byte order (big-endian)
 struct BinaryProtocol {
-    static let headerSize = 13
+    static let v1HeaderSize = 14
+    static let v2HeaderSize = 16
    static let senderIDSize = 8
    static let recipientIDSize = 8
    static let signatureSize = 64
+
+    // Field offsets within packet header
+    struct Offsets {
+        static let version = 0
+        static let type = 1
+        static let ttl = 2
+        static let timestamp = 3
+        static let flags = 11  // After version(1) + type(1) + ttl(1) + timestamp(8)
+    }
+
+    static func headerSize(for version: UInt8) -> Int? {
+        switch version {
+        case 1: return v1HeaderSize
+        case 2: return v2HeaderSize
+        default: return nil
+        }
+    }
+
+    private static func lengthFieldSize(for version: UInt8) -> Int {
+        return version == 2 ? 4 : 2
+    }
    
    struct Flags {
        static let hasRecipient: UInt8 = 0x01
        static let hasSignature: UInt8 = 0x02
        static let isCompressed: UInt8 = 0x04
+        static let hasRoute: UInt8 = 0x08
+        static let isRSR: UInt8 = 0x10
    }
    
    // Encode BitchatPacket to binary format
    static func encode(_ packet: BitchatPacket, padding: Bool = true) -> Data? {
-        var data = Data()
-        
-        
-        // Try to compress payload if beneficial
+        let version = packet.version
+        guard version == 1 || version == 2 else { return nil }
+
+        // Try to compress payload when beneficial, keeping original size for later decoding
        var payload = packet.payload
-        var originalPayloadSize: UInt16? = nil
        var isCompressed = false
-        
+        var originalPayloadSize: Int?
        if CompressionUtil.shouldCompress(payload) {
-            if let compressedPayload = CompressionUtil.compress(payload) {
-                // Store original size for decompression (2 bytes after payload)
-                originalPayloadSize = UInt16(payload.count)
+            // Only compress when we can represent the original length in the outbound frame
+            let maxRepresentable = version == 2 ? Int(UInt32.max) : Int(UInt16.max)
+            if payload.count <= maxRepresentable,
+               let compressedPayload = CompressionUtil.compress(payload) {
+                originalPayloadSize = payload.count
                payload = compressedPayload
                isCompressed = true
-                
-            } else {
            }
-        } else {
        }
+
+        let lengthFieldBytes = lengthFieldSize(for: version)
        
-        // Header
-        // Reserve capacity to reduce reallocations. Estimate base size conservatively.
-        // header(13) + sender(8) + opt recipient(8) + opt originalSize(2) + payload + opt signature(64) + up to 255 pad
-        let estimatedPayload = payload.count + (isCompressed ? 2 : 0)
-        let estimated = headerSize + senderIDSize + (packet.recipientID == nil ? 0 : recipientIDSize) + estimatedPayload + (packet.signature == nil ? 0 : signatureSize) + 255
-        data.reserveCapacity(estimated)
-        data.append(packet.version)
+        // Route is only supported for v2+ packets (per SOURCE_ROUTING.md spec)
+        let originalRoute = (version >= 2) ? (packet.route ?? []) : []
+        if originalRoute.contains(where: { $0.isEmpty }) { return nil }
+        let sanitizedRoute: [Data] = originalRoute.map { hop in
+            if hop.count == senderIDSize { return hop }
+            if hop.count > senderIDSize { return Data(hop.prefix(senderIDSize)) }
+            var padded = hop
+            padded.append(Data(repeating: 0, count: senderIDSize - hop.count))
+            return padded
+        }
+        guard sanitizedRoute.count <= 255 else { return nil }
+
+        let hasRoute = !sanitizedRoute.isEmpty
+        let routeLength = hasRoute ? 1 + sanitizedRoute.count * senderIDSize : 0
+        let originalSizeFieldBytes = isCompressed ? lengthFieldBytes : 0
+        // payloadLength in header is payload-only (does NOT include route bytes)
+        let payloadDataSize = payload.count + originalSizeFieldBytes
+
+        if version == 1 && payloadDataSize > Int(UInt16.max) { return nil }
+        if version == 2 && payloadDataSize > Int(UInt32.max) { return nil }
+
+        guard let headerSize = headerSize(for: version) else { return nil }
+        let estimatedHeader = headerSize + senderIDSize + (packet.recipientID == nil ? 0 : recipientIDSize) + routeLength
+        let estimatedPayload = payloadDataSize
+        let estimatedSignature = (packet.signature == nil ? 0 : signatureSize)
+        var data = Data()
+        data.reserveCapacity(estimatedHeader + estimatedPayload + estimatedSignature + 255)
+
+        data.append(version)
        data.append(packet.type)
        data.append(packet.ttl)
-        
-        // Timestamp (8 bytes, big-endian)
-        for i in (0..<8).reversed() {
-            data.append(UInt8((packet.timestamp >> (i * 8)) & 0xFF))
+
+        for shift in stride(from: 56, through: 0, by: -8) {
+            data.append(UInt8((packet.timestamp >> UInt64(shift)) & 0xFF))
        }
-        
-        // Flags
+
        var flags: UInt8 = 0
-        if packet.recipientID != nil {
-            flags |= Flags.hasRecipient
-        }
-        if packet.signature != nil {
-            flags |= Flags.hasSignature
-        }
-        if isCompressed {
-            flags |= Flags.isCompressed
-        }
+        if packet.recipientID != nil { flags |= Flags.hasRecipient }
+        if packet.signature != nil { flags |= Flags.hasSignature }
+        if isCompressed { flags |= Flags.isCompressed }
+        // HAS_ROUTE is only valid for v2+ packets
+        if hasRoute && version >= 2 { flags |= Flags.hasRoute }
+        if packet.isRSR { flags |= Flags.isRSR }
        data.append(flags)
        
-        // Payload length (2 bytes, big-endian) - includes original size if compressed
-        let payloadDataSize = payload.count + (isCompressed ? 2 : 0)
-        let payloadLength = UInt16(payloadDataSize)
-        
-        
-        data.append(UInt8((payloadLength >> 8) & 0xFF))
-        data.append(UInt8(payloadLength & 0xFF))
-        
-        // SenderID (exactly 8 bytes)
+        if version == 2 {
+            let length = UInt32(payloadDataSize)
+            for shift in stride(from: 24, through: 0, by: -8) {
+                data.append(UInt8((length >> UInt32(shift)) & 0xFF))
+            }
+        } else {
+            let length = UInt16(payloadDataSize)
+            data.append(UInt8((length >> 8) & 0xFF))
+            data.append(UInt8(length & 0xFF))
+        }
+
        let senderBytes = packet.senderID.prefix(senderIDSize)
        data.append(senderBytes)
        if senderBytes.count < senderIDSize {
            data.append(Data(repeating: 0, count: senderIDSize - senderBytes.count))
        }
-        
-        // RecipientID (if present)
+
        if let recipientID = packet.recipientID {
            let recipientBytes = recipientID.prefix(recipientIDSize)
            data.append(recipientBytes)
@@ -189,30 +232,37 @@ struct BinaryProtocol {
                data.append(Data(repeating: 0, count: recipientIDSize - recipientBytes.count))
            }
        }
-        
-        // Payload (with original size prepended if compressed)
+
+        if hasRoute {
+            data.append(UInt8(sanitizedRoute.count))
+            for hop in sanitizedRoute {
+                data.append(hop)
+            }
+        }
+
        if isCompressed, let originalSize = originalPayloadSize {
-            // Prepend original size (2 bytes, big-endian)
-            data.append(UInt8((originalSize >> 8) & 0xFF))
-            data.append(UInt8(originalSize & 0xFF))
+            if version == 2 {
+                let value = UInt32(originalSize)
+                for shift in stride(from: 24, through: 0, by: -8) {
+                    data.append(UInt8((value >> UInt32(shift)) & 0xFF))
+                }
+            } else {
+                let value = UInt16(originalSize)
+                data.append(UInt8((value >> 8) & 0xFF))
+                data.append(UInt8(value & 0xFF))
+            }
        }
        data.append(payload)
-        
-        // Signature (if present)
+
        if let signature = packet.signature {
            data.append(signature.prefix(signatureSize))
        }
-        
-        
-        // Apply padding to standard block sizes for traffic analysis resistance
+
        if padding {
            let optimalSize = MessagePadding.optimalBlockSize(for: data.count)
-            let paddedData = MessagePadding.pad(data, toSize: optimalSize)
-            return paddedData
-        } else {
-            // Caller explicitly requested no padding (e.g., BLE write path)
-            return data
+            return MessagePadding.pad(data, toSize: optimalSize)
        }
+        return data
    }
    
    // Decode binary data to BitchatPacket
@@ -227,87 +277,126 @@ struct BinaryProtocol {

    // Core decoding implementation used by decode(_:) with and without padding removal
    private static func decodeCore(_ raw: Data) -> BitchatPacket? {
-        // Minimum size: header + senderID
-        guard raw.count >= headerSize + senderIDSize else { return nil }
+        guard raw.count >= v1HeaderSize + senderIDSize else { return nil }

        return raw.withUnsafeBytes { (buf: UnsafeRawBufferPointer) -> BitchatPacket? in
            guard let base = buf.baseAddress else { return nil }
            var offset = 0
            func require(_ n: Int) -> Bool { offset + n <= buf.count }
-            // Read single byte
            func read8() -> UInt8? {
                guard require(1) else { return nil }
-                let v = base.advanced(by: offset).assumingMemoryBound(to: UInt8.self).pointee
+                let value = base.advanced(by: offset).assumingMemoryBound(to: UInt8.self).pointee
                offset += 1
-                return v
+                return value
            }
-            // Read big-endian 16-bit
            func read16() -> UInt16? {
                guard require(2) else { return nil }
-                let p = base.advanced(by: offset).assumingMemoryBound(to: UInt8.self)
-                let v = (UInt16(p[0]) << 8) | UInt16(p[1])
+                let ptr = base.advanced(by: offset).assumingMemoryBound(to: UInt8.self)
+                let value = (UInt16(ptr[0]) << 8) | UInt16(ptr[1])
                offset += 2
-                return v
+                return value
+            }
+            func read32() -> UInt32? {
+                guard require(4) else { return nil }
+                let ptr = base.advanced(by: offset).assumingMemoryBound(to: UInt8.self)
+                let value = (UInt32(ptr[0]) << 24) | (UInt32(ptr[1]) << 16) | (UInt32(ptr[2]) << 8) | UInt32(ptr[3])
+                offset += 4
+                return value
            }
-            // Copy N bytes into Data
            func readData(_ n: Int) -> Data? {
                guard require(n) else { return nil }
                let ptr = base.advanced(by: offset)
-                let d = Data(bytes: ptr, count: n)
+                let data = Data(bytes: ptr, count: n)
                offset += n
-                return d
+                return data
            }

-            // Version
-            guard let version = read8(), version == 1 else { return nil }
-            guard let type = read8() else { return nil }
-            guard let ttl = read8() else { return nil }
+            guard let version = read8(), version == 1 || version == 2 else { return nil }
+            let lengthFieldBytes = lengthFieldSize(for: version)
+            guard let headerSize = headerSize(for: version) else { return nil }
+            let minimumRequired = headerSize + senderIDSize
+            guard raw.count >= minimumRequired else { return nil }

-            // Timestamp 8 bytes BE
-            guard require(8) else { return nil }
-            var ts: UInt64 = 0
+            guard let type = read8(), let ttl = read8() else { return nil }
+
+            var timestamp: UInt64 = 0
            for _ in 0..<8 {
-                guard let b = read8() else { return nil }
-                ts = (ts << 8) | UInt64(b)
+                guard let byte = read8() else { return nil }
+                timestamp = (timestamp << 8) | UInt64(byte)
            }

-            // Flags
            guard let flags = read8() else { return nil }
            let hasRecipient = (flags & Flags.hasRecipient) != 0
            let hasSignature = (flags & Flags.hasSignature) != 0
            let isCompressed = (flags & Flags.isCompressed) != 0
+            // HAS_ROUTE is only valid for v2+ packets; ignore the flag for v1
+            let hasRoute = (version >= 2) && (flags & Flags.hasRoute) != 0
+            let isRSR = (flags & Flags.isRSR) != 0
+            
+            let payloadLength: Int
+            if version == 2 {
+                guard let len = read32() else { return nil }
+                payloadLength = Int(len)
+            } else {
+                guard let len = read16() else { return nil }
+                payloadLength = Int(len)
+            }

-            // Payload length
-            guard let payloadLen = read16(), payloadLen <= 65535 else { return nil }
+            guard payloadLength >= 0 else { return nil }
+            guard payloadLength <= FileTransferLimits.maxFramedFileBytes else { return nil }

-            // SenderID
            guard let senderID = readData(senderIDSize) else { return nil }

-            // Recipient
            var recipientID: Data? = nil
            if hasRecipient {
                recipientID = readData(recipientIDSize)
                if recipientID == nil { return nil }
            }

-            // Payload
+            // Route (optional, v2+ only): route bytes are NOT included in payloadLength
+            var route: [Data]? = nil
+            if hasRoute {
+                guard let routeCount = read8() else { return nil }
+                if routeCount > 0 {
+                    var hops: [Data] = []
+                    for _ in 0..<Int(routeCount) {
+                        guard let hop = readData(senderIDSize) else { return nil }
+                        hops.append(hop)
+                    }
+                    route = hops
+                }
+            }
+
+            // Payload: payloadLength is exactly the payload size (+ compression preamble if compressed)
            let payload: Data
            if isCompressed {
-                // Need original size (2 bytes)
-                guard let origSize16 = read16() else { return nil }
-                let originalSize = Int(origSize16)
-                guard originalSize >= 0 && originalSize <= 1_048_576 else { return nil }
-                let compSize = Int(payloadLen) - 2
-                guard compSize >= 0, let compressed = readData(compSize) else { return nil }
+                guard payloadLength >= lengthFieldBytes else { return nil }
+                let originalSize: Int
+                if version == 2 {
+                    guard let rawSize = read32() else { return nil }
+                    originalSize = Int(rawSize)
+                } else {
+                    guard let rawSize = read16() else { return nil }
+                    originalSize = Int(rawSize)
+                }
+                guard originalSize >= 0 && originalSize <= FileTransferLimits.maxFramedFileBytes else { return nil }
+                let compressedSize = payloadLength - lengthFieldBytes
+                guard compressedSize > 0, let compressed = readData(compressedSize) else { return nil }
+
+                let compressionRatio = Double(originalSize) / Double(compressedSize)
+                guard compressionRatio <= 50_000.0 else {
+                    SecureLogger.warning("🚫 Suspicious compression ratio: \(String(format: "%.0f", compressionRatio)):1", category: .security)
+                    return nil
+                }
+
                guard let decompressed = CompressionUtil.decompress(compressed, originalSize: originalSize),
                      decompressed.count == originalSize else { return nil }
                payload = decompressed
            } else {
-                guard let p = readData(Int(payloadLen)) else { return nil }
-                payload = p
+                guard let rawPayload = readData(payloadLength) else { return nil }
+                payload = rawPayload
            }

-            // Signature
            var signature: Data? = nil
            if hasSignature {
                signature = readData(signatureSize)
@@ -320,10 +409,13 @@ struct BinaryProtocol {
                type: type,
                senderID: senderID,
                recipientID: recipientID,
-                timestamp: ts,
+                timestamp: timestamp,
                payload: payload,
                signature: signature,
-                ttl: ttl
+                ttl: ttl,
+                version: version,
+                route: route,
+                isRSR: isRSR
            )
        }
    }
@@ -0,0 +1,155 @@
+//
+// BitchatFilePacket.swift
+// bitchat
+//
+// This is free and unencumbered software released into the public domain.
+// For more information, see <https://unlicense.org>
+//
+
+import Foundation
+import BitLogger
+
+/// TLV payload for Bluetooth mesh file transfers (voice notes, images, generic files).
+/// Mirrors the Android client specification to ensure cross-platform interoperability.
+struct BitchatFilePacket {
+    var fileName: String?
+    var fileSize: UInt64?
+    var mimeType: String?
+    var content: Data
+
+    /// Canonical TLV tags defined by the Android implementation.
+    private enum TLVType: UInt8 {
+        case fileName = 0x01
+        case fileSize = 0x02
+        case mimeType = 0x03
+        case content = 0x04
+    }
+
+    /// Encodes the packet using v2 canonical TLVs (4-byte FILE_SIZE, 4-byte CONTENT length).
+    /// Returns `nil` when fields exceed protocol limits (e.g., content > UInt32.max).
+    func encode() -> Data? {
+        let resolvedSize = fileSize ?? UInt64(content.count)
+        guard resolvedSize <= UInt64(UInt32.max) else { return nil }
+        guard resolvedSize <= UInt64(FileTransferLimits.maxPayloadBytes) else { return nil }
+        guard content.count <= Int(UInt32.max) else { return nil }
+        guard FileTransferLimits.isValidPayload(content.count) else { return nil }
+
+        func appendBE<T: FixedWidthInteger>(_ value: T, into data: inout Data) {
+            var big = value.bigEndian
+            withUnsafeBytes(of: &big) { data.append(contentsOf: $0) }
+        }
+
+        var encoded = Data()
+
+        if let name = fileName, let nameData = name.data(using: .utf8), nameData.count <= Int(UInt16.max) {
+            encoded.append(TLVType.fileName.rawValue)
+            appendBE(UInt16(nameData.count), into: &encoded)
+            encoded.append(nameData)
+        }
+
+        encoded.append(TLVType.fileSize.rawValue)
+        appendBE(UInt16(4), into: &encoded)
+        appendBE(UInt32(resolvedSize), into: &encoded)
+
+        if let mime = mimeType, let mimeData = mime.data(using: .utf8), mimeData.count <= Int(UInt16.max) {
+            encoded.append(TLVType.mimeType.rawValue)
+            appendBE(UInt16(mimeData.count), into: &encoded)
+            encoded.append(mimeData)
+        }
+
+        encoded.append(TLVType.content.rawValue)
+        appendBE(UInt32(content.count), into: &encoded)
+        encoded.append(content)
+
+        return encoded
+    }
+
+    /// Decodes TLV payloads, tolerating legacy encodings (FILE_SIZE len=8, CONTENT len=2) when possible.
+    static func decode(_ data: Data) -> BitchatFilePacket? {
+        var cursor = data.startIndex
+        let end = data.endIndex
+
+        var fileName: String?
+        var fileSize: UInt64?
+        var mimeType: String?
+        var content = Data()
+
+        while cursor < end {
+            let typeRaw = data[cursor]
+            cursor = data.index(after: cursor)
+
+            guard cursor <= end else { return nil }
+            let tlvType = TLVType(rawValue: typeRaw)
+
+            func readBigEndianLength(bytes: Int) -> Int? {
+                guard data.distance(from: cursor, to: end) >= bytes else { return nil }
+                // Use UInt64 to prevent integer overflow during shift operations
+                var result: UInt64 = 0
+                for _ in 0..<bytes {
+                    result = (result << 8) | UInt64(data[cursor])
+                    cursor = data.index(after: cursor)
+                }
+                // Safely convert to Int with overflow check
+                guard result <= Int.max else { return nil }
+                return Int(result)
+            }
+
+            let length: Int?
+            if tlvType == .content {
+                let snapshot = cursor
+                let canonical = readBigEndianLength(bytes: 4)
+                if let canonical = canonical,
+                   canonical <= data.distance(from: cursor, to: end) {
+                    length = canonical
+                } else {
+                    cursor = snapshot
+                    length = readBigEndianLength(bytes: 2)
+                }
+            } else {
+                length = readBigEndianLength(bytes: 2)
+            }
+
+            guard let tlvLength = length, tlvLength >= 0 else { return nil }
+            guard data.distance(from: cursor, to: end) >= tlvLength else { return nil }
+
+            let valueStart = cursor
+            cursor = data.index(cursor, offsetBy: tlvLength)
+            let value = data[valueStart..<cursor]
+
+            switch tlvType {
+            case .fileName:
+                fileName = String(data: Data(value), encoding: .utf8)
+            case .fileSize:
+                if tlvLength == 4 || tlvLength == 8 {
+                    var size: UInt64 = 0
+                    for byte in value {
+                        size = (size << 8) | UInt64(byte)
+                    }
+                    if size > UInt64(FileTransferLimits.maxPayloadBytes) {
+                        return nil
+                    }
+                    fileSize = size
+                }
+            case .mimeType:
+                mimeType = String(data: Data(value), encoding: .utf8)
+            case .content:
+                let proposedSize = content.count + value.count
+                if proposedSize > FileTransferLimits.maxPayloadBytes {
+                    return nil
+                }
+                content.append(contentsOf: value)
+            case nil:
+                continue
+            }
+        }
+
+        guard !content.isEmpty else { return nil }
+        guard FileTransferLimits.isValidPayload(content.count) else { return nil }
+        return BitchatFilePacket(
+            fileName: fileName,
+            fileSize: fileSize ?? UInt64(content.count),
+            mimeType: mimeType,
+            content: content
+        )
+    }
+}
@@ -60,6 +60,7 @@

 import Foundation
 import CoreBluetooth
+import BitFoundation

 // MARK: - Message Types

@@ -79,6 +80,7 @@ enum MessageType: UInt8 {
    
    // Fragmentation (simplified)
    case fragment = 0x20        // Single fragment type for large messages
+    case fileTransfer = 0x22    // Binary file/audio/image payloads
    
    var description: String {
        switch self {
@@ -89,6 +91,7 @@ enum MessageType: UInt8 {
        case .noiseHandshake: return "noiseHandshake"
        case .noiseEncrypted: return "noiseEncrypted"
        case .fragment: return "fragment"
+        case .fileTransfer: return "fileTransfer"
        }
    }
 }
@@ -176,7 +179,7 @@ protocol BitchatDelegate: AnyObject {

    // Bluetooth state updates for user notifications
    func didUpdateBluetoothState(_ state: CBManagerState)
-    func didReceivePublicMessage(from peerID: PeerID, nickname: String, content: String, timestamp: Date)
+    func didReceivePublicMessage(from peerID: PeerID, nickname: String, content: String, timestamp: Date, messageID: String?)
 }

 // Provide default implementation to make it effectively optional
@@ -193,7 +196,7 @@ extension BitchatDelegate {
        // Default empty implementation
    }

-    func didReceivePublicMessage(from peerID: PeerID, nickname: String, content: String, timestamp: Date) {
+    func didReceivePublicMessage(from peerID: PeerID, nickname: String, content: String, timestamp: Date, messageID: String?) {
        // Default empty implementation
    }
 }
@@ -119,4 +119,57 @@ enum Geohash {
        }
        return (latInterval.0, latInterval.1, lonInterval.0, lonInterval.1)
    }
+
+    /// Returns all 8 neighboring geohash cells at the same precision.
+    /// - Parameter geohash: Base32 geohash string.
+    /// - Returns: Array of 8 neighboring geohashes (N, NE, E, SE, S, SW, W, NW order).
+    static func neighbors(of geohash: String) -> [String] {
+        guard !geohash.isEmpty else { return [] }
+
+        let precision = geohash.count
+        let bounds = decodeBounds(geohash)
+        let center = decodeCenter(geohash)
+
+        // Calculate cell dimensions
+        let latHeight = bounds.latMax - bounds.latMin
+        let lonWidth = bounds.lonMax - bounds.lonMin
+
+        // Helper to wrap longitude around ±180
+        func wrapLongitude(_ lon: Double) -> Double {
+            var wrapped = lon
+            while wrapped > 180.0 { wrapped -= 360.0 }
+            while wrapped < -180.0 { wrapped += 360.0 }
+            return wrapped
+        }
+
+        // Helper to clamp latitude to ±90
+        func clampLatitude(_ lat: Double) -> Double {
+            return max(-90.0, min(90.0, lat))
+        }
+
+        // Calculate 8 neighbor centers
+        let neighbors: [(lat: Double, lon: Double)] = [
+            (center.lat + latHeight, center.lon),                    // N
+            (center.lat + latHeight, center.lon + lonWidth),         // NE
+            (center.lat, center.lon + lonWidth),                     // E
+            (center.lat - latHeight, center.lon + lonWidth),         // SE
+            (center.lat - latHeight, center.lon),                    // S
+            (center.lat - latHeight, center.lon - lonWidth),         // SW
+            (center.lat, center.lon - lonWidth),                     // W
+            (center.lat + latHeight, center.lon - lonWidth)          // NW
+        ]
+
+        // Encode each neighbor, handling boundary conditions
+        return neighbors.compactMap { neighbor in
+            let lat = clampLatitude(neighbor.lat)
+            let lon = wrapLongitude(neighbor.lon)
+
+            // Skip if we've crossed a pole (latitude clamped to boundary)
+            if (neighbor.lat > 90.0 || neighbor.lat < -90.0) {
+                return nil
+            }
+
+            return encode(latitude: lat, longitude: lon, precision: precision)
+        }
+    }
 }
@@ -116,4 +116,18 @@ enum ChannelID: Equatable, Codable {
        case .location(let ch): return ch.geohash
        }
    }
+    
+    var isMesh: Bool {
+        switch self {
+        case .mesh:     true
+        case .location: false
+        }
+    }
+    
+    var isLocation: Bool {
+        switch self {
+        case .mesh:     false
+        case .location: true
+        }
+    }
 }
@@ -6,11 +6,13 @@ struct AnnouncementPacket {
    let nickname: String
    let noisePublicKey: Data            // Noise static public key (Curve25519.KeyAgreement)
    let signingPublicKey: Data          // Ed25519 public key for signing
+    let directNeighbors: [Data]?        // 8-byte peer IDs

    private enum TLVType: UInt8 {
        case nickname = 0x01
        case noisePublicKey = 0x02
        case signingPublicKey = 0x03
+        case directNeighbors = 0x04
    }

    func encode() -> Data? {
@@ -35,6 +37,16 @@ struct AnnouncementPacket {
        data.append(TLVType.signingPublicKey.rawValue)
        data.append(UInt8(signingPublicKey.count))
        data.append(signingPublicKey)
+        
+        // TLV for direct neighbors (optional)
+        if let neighbors = directNeighbors, !neighbors.isEmpty {
+            let neighborsData = neighbors.prefix(10).reduce(Data()) { $0 + $1 }
+            if !neighborsData.isEmpty && neighborsData.count % 8 == 0 {
+                data.append(TLVType.directNeighbors.rawValue)
+                data.append(UInt8(neighborsData.count))
+                data.append(neighborsData)
+            }
+        }

        return data
    }
@@ -44,6 +56,7 @@ struct AnnouncementPacket {
        var nickname: String?
        var noisePublicKey: Data?
        var signingPublicKey: Data?
+        var directNeighbors: [Data]?

        while offset + 2 <= data.count {
            let typeRaw = data[offset]
@@ -63,6 +76,17 @@ struct AnnouncementPacket {
                    noisePublicKey = Data(value)
                case .signingPublicKey:
                    signingPublicKey = Data(value)
+                case .directNeighbors:
+                    if length > 0 && length % 8 == 0 {
+                        var neighbors = [Data]()
+                        let count = length / 8
+                        for i in 0..<count {
+                            let start = value.startIndex + i * 8
+                            let end = start + 8
+                            neighbors.append(Data(value[start..<end]))
+                        }
+                        directNeighbors = neighbors
+                    }
                }
            } else {
                // Unknown TLV; skip (tolerant decoder for forward compatibility)
@@ -74,7 +98,8 @@ struct AnnouncementPacket {
        return AnnouncementPacket(
            nickname: nickname,
            noisePublicKey: noisePublicKey,
-            signingPublicKey: signingPublicKey
+            signingPublicKey: signingPublicKey,
+            directNeighbors: directNeighbors
        )
    }
 }
@@ -0,0 +1,212 @@
+//
+// MimeType.swift
+// bitchat
+//
+// This is free and unencumbered software released into the public domain.
+// For more information, see <https://unlicense.org>
+//
+
+import UniformTypeIdentifiers
+
+// MARK: - Extensions for missing UTTypes
+
+extension UTType {
+    static let webP = UTType(importedAs: "image/webp")
+    static let aac  = UTType(importedAs: "audio/aac")
+    static let m4a  = UTType(importedAs: "audio/m4a")
+    static let ogg  = UTType(importedAs: "audio/ogg")
+}
+
+// MARK: - MimeType Enum
+
+enum MimeType: CaseIterable, Hashable {
+    case jpeg
+    case jpg
+    case png
+    case gif
+    case webp
+    case mp4Audio
+    case m4a
+    case aac
+    case mpeg
+    case mp3
+    case wav
+    case xWav
+    case ogg
+    case pdf
+    case octetStream
+
+    var utType: UTType {
+        switch self {
+        case .jpeg, .jpg:   .jpeg
+        case .png:          .png
+        case .gif:          .gif
+        case .webp:         .webP
+        case .aac:          .aac
+        case .m4a:          .m4a
+        case .mp4Audio:     .mpeg4Audio
+        case .mp3, .mpeg:   .mp3
+        case .wav, .xWav:   .wav
+        case .ogg:          .ogg
+        case .pdf:          .pdf
+        case .octetStream:  .data
+        }
+    }
+    
+    var category: Category {
+        switch self {
+        case .jpeg, .jpg, .png, .gif, .webp:
+            return .image
+        case .aac, .m4a, .mp4Audio, .mpeg, .mp3, .wav, .xWav, .ogg:
+            return .audio
+        case .pdf, .octetStream:
+            return .file
+        }
+    }
+
+
+    var mimeString: String {
+        switch self {
+        case .jpeg, .jpg:   "image/jpeg"
+        case .png:          "image/png"
+        case .gif:          "image/gif"
+        case .webp:         "image/webp"
+        case .mp4Audio:     "audio/mp4"
+        case .m4a:          "audio/m4a"
+        case .aac:          "audio/aac"
+        case .mpeg:         "audio/mpeg"
+        case .mp3:          "audio/mp3"
+        case .wav:          "audio/wav"
+        case .xWav:         "audio/x-wav"
+        case .ogg:          "audio/ogg"
+        case .pdf:          "application/pdf"
+        case .octetStream:  "application/octet-stream"
+        }
+    }
+    
+    var defaultExtension: String {
+        switch self {
+        case .jpeg, .jpg:           "jpg"
+        case .png:                  "png"
+        case .webp:                 "webp"
+        case .gif:                  "gif"
+        case .mp4Audio, .m4a, .aac: "m4a"
+        case .mpeg, .mp3:           "mp3"
+        case .wav, .xWav:           "wav"
+        case .ogg:                  "ogg"
+        case .pdf:                  "pdf"
+        case .octetStream:          "bin"
+        }
+    }
+
+    static var allowed: Set<MimeType> = [
+        .jpeg, .jpg, .png, .gif, .webp,
+        .mp4Audio, .m4a, .aac, .mpeg, .mp3,
+        .wav, .xWav, .ogg,
+        .pdf, .octetStream
+    ]
+
+    var isAllowed: Bool {
+        Self.allowed.contains(self)
+    }
+
+    // MARK: - Byte signature validation
+    func matches(data: Data) -> Bool {
+        guard !data.isEmpty else { return false }
+
+        // Generic type → skip validation
+        if self == .octetStream { return true }
+
+        switch self {
+        case .jpeg, .jpg:
+            return data.count >= 3 && data[0] == 0xFF && data[1] == 0xD8 && data[2] == 0xFF
+
+        case .png:
+            return data.count >= 8 &&
+                   data[0] == 0x89 && data[1] == 0x50 && data[2] == 0x4E && data[3] == 0x47 &&
+                   data[4] == 0x0D && data[5] == 0x0A && data[6] == 0x1A && data[7] == 0x0A
+
+        case .gif:
+            return data.count >= 6 && data[0] == 0x47 && data[1] == 0x49 && data[2] == 0x46 &&
+                   data[3] == 0x38 && (data[4] == 0x37 || data[4] == 0x39) && data[5] == 0x61
+
+        case .webp:
+            return data.count >= 12 &&
+                   data[0] == 0x52 && data[1] == 0x49 && data[2] == 0x46 && data[3] == 0x46 &&
+                   data[8] == 0x57 && data[9] == 0x45 && data[10] == 0x42 && data[11] == 0x50
+
+        case .m4a, .mp4Audio, .aac:
+            // AVAudioRecorder output varies by platform - be lenient
+            // Security: size already capped + sandboxed execution
+            return data.count > 100
+
+        case .mpeg, .mp3:
+            if data.count >= 3 && data[0] == 0x49 && data[1] == 0x44 && data[2] == 0x33 {
+                return true // ID3 header
+            }
+            return data.count >= 2 && data[0] == 0xFF && (data[1] & 0xE0) == 0xE0
+
+        case .wav, .xWav:
+            return data.count >= 12 &&
+                   data[0] == 0x52 && data[1] == 0x49 && data[2] == 0x46 && data[3] == 0x46 &&
+                   data[8] == 0x57 && data[9] == 0x41 && data[10] == 0x56 && data[11] == 0x45
+
+        case .ogg:
+            return data.count >= 4 &&
+                   data[0] == 0x4F && data[1] == 0x67 && data[2] == 0x67 && data[3] == 0x53
+
+        case .pdf:
+            return data.count >= 4 &&
+                   data[0] == 0x25 && data[1] == 0x50 && data[2] == 0x44 && data[3] == 0x46
+
+        default:
+            return false
+        }
+    }
+
+    // MARK: - Convenience Initializers
+
+    init?(_ mimeString: String?) {
+        guard let mimeString else { return nil }
+        
+        let normalized = mimeString.lowercased()
+
+        // Direct match with our canonical list
+        if let match = MimeType.allCases.first(where: { $0.mimeString == normalized }) {
+            self = match
+            return
+        }
+
+        // Let UTType normalize aliases like "image/jpg", "audio/x-wav", etc.
+        if let type = UTType(mimeType: normalized),
+           let match = MimeType.allCases.first(where: { type.conforms(to: $0.utType) }) {
+            self = match
+            return
+        }
+
+        return nil
+    }
+}
+
+extension MimeType {
+    enum Category: String {
+        case audio, image, file
+
+        /// Ends with a space
+        var messagePrefix: String {
+            switch self {
+            case .audio: "[voice] "
+            case .image: "[image] "
+            case .file: "[file] "
+            }
+        }
+
+        var mediaDir: String {
+            switch self {
+            case .audio: "voicenotes"
+            case .image: "images"
+            case .file: "files"
+            }
+        }
+    }
+}
@@ -7,6 +7,7 @@
 //

 import Foundation
+import BitFoundation

 /// Result of command processing
 enum CommandResult {
@@ -15,15 +16,52 @@ enum CommandResult {
    case handled  // Command handled, no message needed
 }

+/// Simple struct for geo participant info used by CommandProcessor
+struct CommandGeoParticipant {
+    let id: String        // pubkey hex (lowercased)
+    let displayName: String
+}
+
+/// Protocol defining what CommandProcessor needs from its context.
+/// This breaks the circular dependency between CommandProcessor and ChatViewModel.
+@MainActor
+protocol CommandContextProvider: AnyObject {
+    // MARK: - State Properties
+    var nickname: String { get }
+    var selectedPrivateChatPeer: PeerID? { get }
+    var blockedUsers: Set<String> { get }
+    var privateChats: [PeerID: [BitchatMessage]] { get set }
+    var idBridge: NostrIdentityBridge { get }
+
+    // MARK: - Peer Lookup
+    func getPeerIDForNickname(_ nickname: String) -> PeerID?
+    func getVisibleGeoParticipants() -> [CommandGeoParticipant]
+    func nostrPubkeyForDisplayName(_ displayName: String) -> String?
+
+    // MARK: - Chat Actions
+    func startPrivateChat(with peerID: PeerID)
+    func sendPrivateMessage(_ content: String, to peerID: PeerID)
+    func clearCurrentPublicTimeline()
+    func sendPublicRaw(_ content: String)
+
+    // MARK: - System Messages
+    func addLocalPrivateSystemMessage(_ content: String, to peerID: PeerID)
+    func addPublicSystemMessage(_ content: String)
+
+    // MARK: - Favorites
+    func toggleFavorite(peerID: PeerID)
+    func sendFavoriteNotification(to peerID: PeerID, isFavorite: Bool)
+}
+
 /// Processes chat commands in a focused, efficient way
@MainActor
 final class CommandProcessor {
-    weak var chatViewModel: ChatViewModel?
+    weak var contextProvider: CommandContextProvider?
    weak var meshService: Transport?
    private let identityManager: SecureIdentityStateManagerProtocol
-    
-    init(chatViewModel: ChatViewModel? = nil, meshService: Transport? = nil, identityManager: SecureIdentityStateManagerProtocol) {
-        self.chatViewModel = chatViewModel
+
+    init(contextProvider: CommandContextProvider? = nil, meshService: Transport? = nil, identityManager: SecureIdentityStateManagerProtocol) {
+        self.contextProvider = contextProvider
        self.meshService = meshService
        self.identityManager = identityManager
    }
@@ -42,7 +80,7 @@ final class CommandProcessor {
            case .location: return true
            }
        }()
-        let inGeoDM = (chatViewModel?.selectedPrivateChatPeer?.hasPrefix("nostr_") == true)
+        let inGeoDM = contextProvider?.selectedPrivateChatPeer?.isGeoDM == true

        switch cmd {
        case "/m", "/msg":
@@ -65,14 +103,11 @@ final class CommandProcessor {
        case "/unfav":
            if inGeoPublic || inGeoDM { return .error(message: "favorites are only for mesh peers in #mesh") }
            return handleFavorite(args, add: false)
-        //
-        case "/help", "/h":
-            return .error(message: "unknown command: \(cmd)")
        default:
            return .error(message: "unknown command: \(cmd)")
        }
    }
-    
+
    // MARK: - Command Handlers
    
    private func handleMessage(_ args: String) -> CommandResult {
@@ -84,15 +119,15 @@ final class CommandProcessor {
        let targetName = String(parts[0])
        let nickname = targetName.hasPrefix("@") ? String(targetName.dropFirst()) : targetName
        
-        guard let peerID = chatViewModel?.getPeerIDForNickname(nickname) else {
+        guard let peerID = contextProvider?.getPeerIDForNickname(nickname) else {
            return .error(message: "'\(nickname)' not found")
        }
-        
-        chatViewModel?.startPrivateChat(with: peerID)
-        
+
+        contextProvider?.startPrivateChat(with: peerID)
+
        if parts.count > 1 {
            let message = String(parts[1])
-            chatViewModel?.sendPrivateMessage(message, to: peerID)
+            contextProvider?.sendPrivateMessage(message, to: peerID)
        }
        
        return .success(message: "started private chat with \(nickname)")
@@ -103,9 +138,9 @@ final class CommandProcessor {
        switch LocationChannelManager.shared.selectedChannel {
        case .location(let ch):
            // Geohash context: show visible geohash participants (exclude self)
-            guard let vm = chatViewModel else { return .success(message: "nobody around") }
-            let myHex = (try? NostrIdentityBridge.deriveIdentity(forGeohash: ch.geohash))?.publicKeyHex.lowercased()
-            let people = vm.visibleGeohashPeople().filter { person in
+            guard let vm = contextProvider else { return .success(message: "nobody around") }
+            let myHex = (try? vm.idBridge.deriveIdentity(forGeohash: ch.geohash))?.publicKeyHex.lowercased()
+            let people = vm.getVisibleGeoParticipants().filter { person in
                if let me = myHex { return person.id.lowercased() != me }
                return true
            }
@@ -123,34 +158,34 @@ final class CommandProcessor {
    }
    
    private func handleClear() -> CommandResult {
-        if let peerID = chatViewModel?.selectedPrivateChatPeer {
-            chatViewModel?.privateChats[peerID]?.removeAll()
+        if let peerID = contextProvider?.selectedPrivateChatPeer {
+            contextProvider?.privateChats[peerID]?.removeAll()
        } else {
-            chatViewModel?.clearCurrentPublicTimeline()
+            contextProvider?.clearCurrentPublicTimeline()
        }
        return .handled
    }
    
    private func handleEmote(_ args: String, command: String, action: String, emoji: String, suffix: String = "") -> CommandResult {
-        let targetName = args.trimmingCharacters(in: .whitespaces)
+        let targetName = args.trimmed
        guard !targetName.isEmpty else {
            return .error(message: "usage: /\(command) <nickname>")
        }
        
        let nickname = targetName.hasPrefix("@") ? String(targetName.dropFirst()) : targetName
        
-        guard let targetPeerID = chatViewModel?.getPeerIDForNickname(nickname),
-              let myNickname = chatViewModel?.nickname else {
+        guard let targetPeerID = contextProvider?.getPeerIDForNickname(nickname),
+              let myNickname = contextProvider?.nickname else {
            return .error(message: "cannot \(command) \(nickname): not found")
        }
        
        let emoteContent = "* \(emoji) \(myNickname) \(action) \(nickname)\(suffix) *"
        
-        if chatViewModel?.selectedPrivateChatPeer != nil {
+        if contextProvider?.selectedPrivateChatPeer != nil {
            // In private chat
-            if let peerNickname = meshService?.peerNickname(peerID: PeerID(str: targetPeerID)) {
+            if let peerNickname = meshService?.peerNickname(peerID: targetPeerID) {
                let personalMessage = "* \(emoji) \(myNickname) \(action) you\(suffix) *"
-                meshService?.sendPrivateMessage(personalMessage, to: PeerID(str: targetPeerID),
+                meshService?.sendPrivateMessage(personalMessage, to: targetPeerID,
                                               recipientNickname: peerNickname,
                                               messageID: UUID().uuidString)
                // Also add a local system message so the sender sees a natural-language confirmation
@@ -162,24 +197,24 @@ final class CommandProcessor {
                    }
                }()
                let localText = "\(emoji) you \(pastAction) \(nickname)\(suffix)"
-                chatViewModel?.addLocalPrivateSystemMessage(localText, to: targetPeerID)
+                contextProvider?.addLocalPrivateSystemMessage(localText, to: targetPeerID)
            }
        } else {
            // In public chat: send to active public channel (mesh or geohash)
-            chatViewModel?.sendPublicRaw(emoteContent)
+            contextProvider?.sendPublicRaw(emoteContent)
            let publicEcho = "\(emoji) \(myNickname) \(action) \(nickname)\(suffix)"
-            chatViewModel?.addPublicSystemMessage(publicEcho)
+            contextProvider?.addPublicSystemMessage(publicEcho)
        }
        
        return .handled
    }
    
    private func handleBlock(_ args: String) -> CommandResult {
-        let targetName = args.trimmingCharacters(in: .whitespaces)
+        let targetName = args.trimmed
        
        if targetName.isEmpty {
            // List blocked users (mesh) and geohash (Nostr) blocks
-            let meshBlocked = chatViewModel?.blockedUsers ?? []
+            let meshBlocked = contextProvider?.blockedUsers ?? []
            var blockedNicknames: [String] = []
            if let peers = meshService?.getPeerNicknames() {
                for (peerID, nickname) in peers {
@@ -193,8 +228,8 @@ final class CommandProcessor {
            // Geohash blocked names (prefer visible display names; fallback to #suffix)
            let geoBlocked = Array(identityManager.getBlockedNostrPubkeys())
            var geoNames: [String] = []
-            if let vm = chatViewModel {
-                let visible = vm.visibleGeohashPeople()
+            if let vm = contextProvider {
+                let visible = vm.getVisibleGeoParticipants()
                let visibleIndex = Dictionary(uniqueKeysWithValues: visible.map { ($0.id.lowercased(), $0.displayName) })
                for pk in geoBlocked {
                    if let name = visibleIndex[pk.lowercased()] {
@@ -213,8 +248,8 @@ final class CommandProcessor {
        
        let nickname = targetName.hasPrefix("@") ? String(targetName.dropFirst()) : targetName
        
-        if let peerID = chatViewModel?.getPeerIDForNickname(nickname),
-           let fingerprint = meshService?.getFingerprint(for: PeerID(str: peerID)) {
+        if let peerID = contextProvider?.getPeerIDForNickname(nickname),
+           let fingerprint = meshService?.getFingerprint(for: peerID) {
            if identityManager.isBlocked(fingerprint: fingerprint) {
                return .success(message: "\(nickname) is already blocked")
            }
@@ -238,7 +273,7 @@ final class CommandProcessor {
            return .success(message: "blocked \(nickname). you will no longer receive messages from them")
        }
        // Mesh lookup failed; try geohash (Nostr) participant by display name
-        if let pub = chatViewModel?.nostrPubkeyForDisplayName(nickname) {
+        if let pub = contextProvider?.nostrPubkeyForDisplayName(nickname) {
            if identityManager.isNostrBlocked(pubkeyHexLowercased: pub) {
                return .success(message: "\(nickname) is already blocked")
            }
@@ -250,15 +285,15 @@ final class CommandProcessor {
    }
    
    private func handleUnblock(_ args: String) -> CommandResult {
-        let targetName = args.trimmingCharacters(in: .whitespaces)
+        let targetName = args.trimmed
        guard !targetName.isEmpty else {
            return .error(message: "usage: /unblock <nickname>")
        }
        
        let nickname = targetName.hasPrefix("@") ? String(targetName.dropFirst()) : targetName
        
-        if let peerID = chatViewModel?.getPeerIDForNickname(nickname),
-           let fingerprint = meshService?.getFingerprint(for: PeerID(str: peerID)) {
+        if let peerID = contextProvider?.getPeerIDForNickname(nickname),
+           let fingerprint = meshService?.getFingerprint(for: peerID) {
            if !identityManager.isBlocked(fingerprint: fingerprint) {
                return .success(message: "\(nickname) is not blocked")
            }
@@ -266,7 +301,7 @@ final class CommandProcessor {
            return .success(message: "unblocked \(nickname)")
        }
        // Try geohash unblock
-        if let pub = chatViewModel?.nostrPubkeyForDisplayName(nickname) {
+        if let pub = contextProvider?.nostrPubkeyForDisplayName(nickname) {
            if !identityManager.isNostrBlocked(pubkeyHexLowercased: pub) {
                return .success(message: "\(nickname) is not blocked")
            }
@@ -277,15 +312,15 @@ final class CommandProcessor {
    }
    
    private func handleFavorite(_ args: String, add: Bool) -> CommandResult {
-        let targetName = args.trimmingCharacters(in: .whitespaces)
+        let targetName = args.trimmed
        guard !targetName.isEmpty else {
            return .error(message: "usage: /\(add ? "fav" : "unfav") <nickname>")
        }
        
        let nickname = targetName.hasPrefix("@") ? String(targetName.dropFirst()) : targetName
        
-        guard let peerID = chatViewModel?.getPeerIDForNickname(nickname),
-              let noisePublicKey = Data(hexString: peerID) else {
+        guard let peerID = contextProvider?.getPeerIDForNickname(nickname),
+              let noisePublicKey = Data(hexString: peerID.id) else {
            return .error(message: "can't find peer: \(nickname)")
        }
        
@@ -297,33 +332,18 @@ final class CommandProcessor {
                peerNickname: nickname
            )
            
-            chatViewModel?.toggleFavorite(peerID: peerID)
-            chatViewModel?.sendFavoriteNotification(to: peerID, isFavorite: true)
+            contextProvider?.toggleFavorite(peerID: peerID)
+            contextProvider?.sendFavoriteNotification(to: peerID, isFavorite: true)
            
            return .success(message: "added \(nickname) to favorites")
        } else {
            FavoritesPersistenceService.shared.removeFavorite(peerNoisePublicKey: noisePublicKey)
            
-            chatViewModel?.toggleFavorite(peerID: peerID)
-            chatViewModel?.sendFavoriteNotification(to: peerID, isFavorite: false)
+            contextProvider?.toggleFavorite(peerID: peerID)
+            contextProvider?.sendFavoriteNotification(to: peerID, isFavorite: false)
            
            return .success(message: "removed \(nickname) from favorites")
        }
    }
    
-    private func handleHelp() -> CommandResult {
-        let helpText = """
-        commands:
-        /msg @name - start private chat
-        /who - list who's online
-        /clear - clear messages
-        /hug @name - send a hug
-        /slap @name - slap with a trout
-        /fav @name - add to favorites
-        /unfav @name - remove from favorites
-        /block @name - block
-        /unblock @name - unblock
-        """
-        return .success(message: helpText)
-    }
 }
@@ -1,4 +1,5 @@
 import BitLogger
+import BitFoundation
 import Foundation
 import Combine

@@ -26,16 +27,15 @@ final class FavoritesPersistenceService: ObservableObject {

    private static let storageKey = "chat.bitchat.favorites"
    private static let keychainService = "chat.bitchat.favorites"
+    private let keychain: KeychainManagerProtocol
    
    @Published private(set) var favorites: [Data: FavoriteRelationship] = [:] // Noise pubkey -> relationship
    @Published private(set) var mutualFavorites: Set<Data> = []
    
-    private let userDefaults = UserDefaults.standard
-    private var cancellables = Set<AnyCancellable>()
-    
    static let shared = FavoritesPersistenceService()
-    
-    private init() {
+
+    init(keychain: KeychainManagerProtocol = KeychainManager()) {
+        self.keychain = keychain
        loadFavorites()
        
        // Update mutual favorites when favorites change
@@ -196,7 +196,7 @@ final class FavoritesPersistenceService: ObservableObject {
        saveFavorites()
        
        // Delete from keychain directly
-        KeychainHelper.delete(
+        keychain.delete(
            key: Self.storageKey,
            service: Self.keychainService
        )
@@ -216,10 +216,11 @@ final class FavoritesPersistenceService: ObservableObject {
            let data = try encoder.encode(relationships)
            
            // Store in keychain for security
-            KeychainHelper.save(
+            keychain.save(
                key: Self.storageKey,
                data: data,
-                service: Self.keychainService
+                service: Self.keychainService,
+                accessible: nil
            )
            
            // Successfully saved favorites
@@ -231,7 +232,7 @@ final class FavoritesPersistenceService: ObservableObject {
    private func loadFavorites() {
        // Loading favorites from keychain
        
-        guard let data = KeychainHelper.load(
+        guard let data = keychain.load(
            key: Self.storageKey,
            service: Self.keychainService
        ) else { 
@@ -1,230 +0,0 @@
-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 let storage: UserDefaults
-
-    init(storage: UserDefaults = .standard) {
-        self.storage = storage
-        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 = storage.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 = storage.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) {
-            storage.set(data, forKey: storeKey)
-        }
-    }
-
-    private func persistNames() {
-        if let data = try? JSONEncoder().encode(bookmarkNames) {
-            storage.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
-}
@@ -0,0 +1,162 @@
+//
+// GeohashParticipantTracker.swift
+// bitchat
+//
+// Tracks participants in geohash-based location channels.
+// This is free and unencumbered software released into the public domain.
+//
+
+import Foundation
+
+/// Represents a participant in a geohash channel
+public struct GeoPerson: Identifiable, Equatable, Sendable {
+    public let id: String        // pubkey hex (lowercased)
+    public let displayName: String
+    public let lastSeen: Date
+
+    public init(id: String, displayName: String, lastSeen: Date) {
+        self.id = id
+        self.displayName = displayName
+        self.lastSeen = lastSeen
+    }
+}
+
+/// Protocol for resolving display names and checking block status
+@MainActor
+public protocol GeohashParticipantContext: AnyObject {
+    /// Returns display name for a Nostr pubkey (e.g., "alice#a1b2" or "anon#c3d4")
+    func displayNameForPubkey(_ pubkeyHex: String) -> String
+    /// Returns true if the pubkey is blocked
+    func isBlocked(_ pubkeyHexLowercased: String) -> Bool
+}
+
+/// Tracks participants across multiple geohash channels
+@MainActor
+public final class GeohashParticipantTracker: ObservableObject {
+
+    /// Activity cutoff duration (defaults to 5 minutes)
+    public let activityCutoff: TimeInterval
+
+    /// Per-geohash participant map: [geohash: [pubkeyHex: lastSeen]]
+    private var participants: [String: [String: Date]] = [:]
+
+    /// Currently visible people for the active geohash
+    @Published public private(set) var visiblePeople: [GeoPerson] = []
+
+    /// The currently active geohash (if any)
+    private var activeGeohash: String?
+
+    /// Context for display name resolution and block checking
+    private weak var context: GeohashParticipantContext?
+
+    /// Timer for periodic refresh
+    private var refreshTimer: Timer?
+
+    public init(activityCutoff: TimeInterval = -300) { // default 5 minutes
+        self.activityCutoff = activityCutoff
+    }
+
+    /// Configure with a context provider
+    public func configure(context: GeohashParticipantContext) {
+        self.context = context
+    }
+
+    /// Set the currently active geohash
+    public func setActiveGeohash(_ geohash: String?) {
+        activeGeohash = geohash
+        if geohash == nil {
+            visiblePeople = []
+        } else {
+            refresh()
+        }
+    }
+
+    /// Record activity from a participant in the current active geohash
+    public func recordParticipant(pubkeyHex: String) {
+        guard let gh = activeGeohash else { return }
+        recordParticipant(pubkeyHex: pubkeyHex, geohash: gh)
+    }
+
+    /// Record activity from a participant in a specific geohash
+    public func recordParticipant(pubkeyHex: String, geohash: String) {
+        let key = pubkeyHex.lowercased()
+        var map = participants[geohash] ?? [:]
+        map[key] = Date()
+        participants[geohash] = map
+        
+        // Always notify observers that state has changed so counts in UI update
+        objectWillChange.send()
+
+        // Only refresh visible list if this geohash is currently active
+        if activeGeohash == geohash {
+            refresh()
+        }
+    }
+
+    /// Remove a participant from all geohashes (used when blocking)
+    public func removeParticipant(pubkeyHex: String) {
+        let key = pubkeyHex.lowercased()
+        for (gh, var map) in participants {
+            map.removeValue(forKey: key)
+            participants[gh] = map
+        }
+        refresh()
+    }
+
+    /// Get participant count for a specific geohash
+    public func participantCount(for geohash: String) -> Int {
+        let cutoff = Date().addingTimeInterval(activityCutoff)
+        let map = participants[geohash] ?? [:]
+        return map.values.filter { $0 >= cutoff }.count
+    }
+
+    /// Get the visible people list for the active geohash (read-only query)
+    public func getVisiblePeople() -> [GeoPerson] {
+        guard let gh = activeGeohash, let context = context else { return [] }
+        let cutoff = Date().addingTimeInterval(activityCutoff)
+        let map = (participants[gh] ?? [:])
+            .filter { $0.value >= cutoff }
+            .filter { !context.isBlocked($0.key) }
+
+        return map
+            .map { (pub, seen) in
+                GeoPerson(id: pub, displayName: context.displayNameForPubkey(pub), lastSeen: seen)
+            }
+            .sorted { $0.lastSeen > $1.lastSeen }
+    }
+
+    /// Refresh the visible people list
+    public func refresh() {
+        visiblePeople = getVisiblePeople()
+    }
+
+    /// Start the periodic refresh timer
+    public func startRefreshTimer(interval: TimeInterval = 30.0) {
+        stopRefreshTimer()
+        refreshTimer = Timer.scheduledTimer(withTimeInterval: interval, repeats: true) { [weak self] _ in
+            Task { @MainActor in
+                self?.refresh()
+            }
+        }
+    }
+
+    /// Stop the periodic refresh timer
+    public func stopRefreshTimer() {
+        refreshTimer?.invalidate()
+        refreshTimer = nil
+    }
+
+    /// Clear all participant data
+    public func clear() {
+        participants.removeAll()
+        visiblePeople = []
+    }
+
+    /// Clear participant data for a specific geohash
+    public func clear(geohash: String) {
+        participants.removeValue(forKey: geohash)
+        if activeGeohash == geohash {
+            visiblePeople = []
+        }
+    }
+}
@@ -0,0 +1,264 @@
+//
+// GeohashPresenceService.swift
+// bitchat
+//
+// Manages the broadcasting of ephemeral presence heartbeats (Kind 20001)
+// to geohash location channels.
+//
+// This is free and unencumbered software released into the public domain.
+//
+
+import Foundation
+import Combine
+import BitLogger
+import Tor
+
+protocol GeohashPresenceTimerProtocol: AnyObject {
+    var isValid: Bool { get }
+    func invalidate()
+}
+
+private final class GeohashPresenceTimerAdapter: GeohashPresenceTimerProtocol {
+    private let base: Timer
+
+    init(base: Timer) {
+        self.base = base
+    }
+
+    var isValid: Bool { base.isValid }
+
+    func invalidate() {
+        base.invalidate()
+    }
+}
+
+/// Service that coordinates the broadcasting of presence heartbeats.
+///
+/// Behavior:
+/// - Monitors location changes via LocationStateManager
+/// - Broadcasts Kind 20001 events to low-precision geohash channels
+/// - Uses randomized timing (40-80s loop) and decorrelated bursts
+/// - Respects privacy by NOT broadcasting to Neighborhood/Block/Building levels
+@MainActor
+final class GeohashPresenceService: ObservableObject {
+    static let shared = GeohashPresenceService()
+
+    private var subscriptions = Set<AnyCancellable>()
+    private var heartbeatTimer: GeohashPresenceTimerProtocol?
+    private let availableChannelsProvider: () -> [GeohashChannel]
+    private let locationChanges: AnyPublisher<[GeohashChannel], Never>
+    private let torReadyPublisher: AnyPublisher<Void, Never>
+    private let torIsReady: () -> Bool
+    private let torIsForeground: () -> Bool
+    private let deriveIdentity: (String) throws -> NostrIdentity
+    private let relayLookup: (String, Int) -> [String]
+    private let relaySender: (NostrEvent, [String]) -> Void
+    private let sleeper: (UInt64) async -> Void
+    private let scheduleTimer: (TimeInterval, @escaping () -> Void) -> GeohashPresenceTimerProtocol
+    
+    // MARK: - Constants
+
+    // Loop interval range in seconds
+    private let loopMinInterval: TimeInterval
+    private let loopMaxInterval: TimeInterval
+    
+    // Per-broadcast decorrelation delay range in seconds
+    private let burstMinDelay: TimeInterval
+    private let burstMaxDelay: TimeInterval
+
+    // Privacy: Only broadcast to these levels
+    private let allowedPrecisions: Set<Int> = [
+        GeohashChannelLevel.region.precision,    // 2
+        GeohashChannelLevel.province.precision,  // 4
+        GeohashChannelLevel.city.precision       // 5
+    ]
+
+    private init() {
+        let idBridge = NostrIdentityBridge()
+        self.availableChannelsProvider = { LocationStateManager.shared.availableChannels }
+        self.locationChanges = LocationStateManager.shared.$availableChannels.eraseToAnyPublisher()
+        self.torReadyPublisher = NotificationCenter.default.publisher(for: .TorDidBecomeReady)
+            .map { _ in () }
+            .eraseToAnyPublisher()
+        self.torIsReady = { TorManager.shared.isReady }
+        self.torIsForeground = { TorManager.shared.isForeground() }
+        self.deriveIdentity = { try idBridge.deriveIdentity(forGeohash: $0) }
+        self.relayLookup = { geohash, count in
+            GeoRelayDirectory.shared.closestRelays(toGeohash: geohash, count: count)
+        }
+        self.relaySender = { event, relays in
+            NostrRelayManager.shared.sendEvent(event, to: relays)
+        }
+        self.sleeper = { nanoseconds in
+            try? await Task.sleep(nanoseconds: nanoseconds)
+        }
+        self.scheduleTimer = { interval, action in
+            GeohashPresenceTimerAdapter(
+                base: Timer.scheduledTimer(withTimeInterval: interval, repeats: false) { _ in
+                    action()
+                }
+            )
+        }
+        self.loopMinInterval = 40.0
+        self.loopMaxInterval = 80.0
+        self.burstMinDelay = 2.0
+        self.burstMaxDelay = 5.0
+        setupObservers()
+    }
+
+    internal init(
+        availableChannelsProvider: @escaping () -> [GeohashChannel],
+        locationChanges: AnyPublisher<[GeohashChannel], Never>,
+        torReadyPublisher: AnyPublisher<Void, Never>,
+        torIsReady: @escaping () -> Bool,
+        torIsForeground: @escaping () -> Bool,
+        deriveIdentity: @escaping (String) throws -> NostrIdentity,
+        relayLookup: @escaping (String, Int) -> [String],
+        relaySender: @escaping (NostrEvent, [String]) -> Void,
+        sleeper: @escaping (UInt64) async -> Void = { nanoseconds in try? await Task.sleep(nanoseconds: nanoseconds) },
+        scheduleTimer: @escaping (TimeInterval, @escaping () -> Void) -> GeohashPresenceTimerProtocol = { interval, action in
+            GeohashPresenceTimerAdapter(
+                base: Timer.scheduledTimer(withTimeInterval: interval, repeats: false) { _ in
+                    action()
+                }
+            )
+        },
+        loopMinInterval: TimeInterval = 40.0,
+        loopMaxInterval: TimeInterval = 80.0,
+        burstMinDelay: TimeInterval = 2.0,
+        burstMaxDelay: TimeInterval = 5.0
+    ) {
+        self.availableChannelsProvider = availableChannelsProvider
+        self.locationChanges = locationChanges
+        self.torReadyPublisher = torReadyPublisher
+        self.torIsReady = torIsReady
+        self.torIsForeground = torIsForeground
+        self.deriveIdentity = deriveIdentity
+        self.relayLookup = relayLookup
+        self.relaySender = relaySender
+        self.sleeper = sleeper
+        self.scheduleTimer = scheduleTimer
+        self.loopMinInterval = loopMinInterval
+        self.loopMaxInterval = loopMaxInterval
+        self.burstMinDelay = burstMinDelay
+        self.burstMaxDelay = burstMaxDelay
+        setupObservers()
+    }
+    
+    /// Start the service (safe to call multiple times)
+    func start() {
+        SecureLogger.info("Presence: service starting...", category: .session)
+        scheduleNextHeartbeat()
+    }
+
+    private func setupObservers() {
+        // Monitor location channel changes
+        locationChanges
+            .dropFirst()
+            .sink { [weak self] _ in
+                self?.handleLocationChange()
+            }
+            .store(in: &subscriptions)
+
+        // Monitor Tor readiness to kick off heartbeat if it was stalled
+        torReadyPublisher
+            .sink { [weak self] _ in
+                self?.handleConnectivityChange()
+            }
+            .store(in: &subscriptions)
+    }
+
+    func handleLocationChange() {
+        // When location changes, we trigger an immediate (but slightly delayed) heartbeat
+        // to announce presence in the new zone, then reset the loop.
+        SecureLogger.debug("Presence: location changed, scheduling update", category: .session)
+        heartbeatTimer?.invalidate()
+        
+        // Small delay to allow location state to settle
+        heartbeatTimer = scheduleTimer(5.0) { [weak self] in
+            Task { @MainActor [weak self] in
+                self?.performHeartbeat()
+            }
+        }
+    }
+    
+    func handleConnectivityChange() {
+        SecureLogger.debug("Presence: connectivity restored, triggering heartbeat", category: .session)
+        // If we were waiting for network, do it now
+        if heartbeatTimer == nil || !heartbeatTimer!.isValid {
+            scheduleNextHeartbeat()
+        }
+    }
+
+    func scheduleNextHeartbeat() {
+        heartbeatTimer?.invalidate()
+        let interval = TimeInterval.random(in: loopMinInterval...loopMaxInterval)
+        heartbeatTimer = scheduleTimer(interval) { [weak self] in
+            Task { @MainActor [weak self] in
+                self?.performHeartbeat()
+            }
+        }
+    }
+
+    func performHeartbeat() {
+        // Always schedule next loop first ensures continuity even if this one fails/skips
+        defer { scheduleNextHeartbeat() }
+
+        // 1. Check preconditions
+        guard torIsReady() else {
+            SecureLogger.debug("Presence: skipping heartbeat (Tor not ready)", category: .session)
+            return
+        }
+        
+        // App must be active (or at least we shouldn't broadcast if in background, usually)
+        if !torIsForeground() {
+            return
+        }
+
+        // 2. Get channels
+        let channels = availableChannelsProvider()
+        guard !channels.isEmpty else { return }
+
+        // 3. Filter and broadcast
+        // We use Task + sleep for decorrelation to allow the main runloop to proceed
+        for channel in channels {
+            // Check privacy restriction
+            if !self.allowedPrecisions.contains(channel.geohash.count) {
+                continue
+            }
+            
+            // Launch independent task for each channel's delay
+            Task { @MainActor in
+                // Random delay for decorrelation
+                let delay = TimeInterval.random(in: self.burstMinDelay...self.burstMaxDelay)
+                let nanoseconds = UInt64(delay * 1_000_000_000)
+                await self.sleeper(nanoseconds)
+                
+                self.broadcastPresence(for: channel.geohash)
+            }
+        }
+    }
+
+    func broadcastPresence(for geohash: String) {
+        do {
+            guard let identity = try? deriveIdentity(geohash) else {
+                return
+            }
+            
+            let event = try NostrProtocol.createGeohashPresenceEvent(
+                geohash: geohash,
+                senderIdentity: identity
+            )
+            
+            // Send via RelayManager
+            let targetRelays = relayLookup(geohash, TransportConfig.nostrGeoRelayCount)
+            
+            if !targetRelays.isEmpty {
+                relaySender(event, targetRelays)
+                SecureLogger.debug("Presence: sent heartbeat for \(geohash) (pub=\(identity.publicKeyHex.prefix(6))...)", category: .session)
+            }
+        } catch {
+            SecureLogger.error("Presence: failed to create event for \(geohash): \(error)", category: .session)
+        }
+    }
+}
@@ -10,16 +10,71 @@ import BitLogger
 import Foundation
 import Security

+// MARK: - Keychain Error Types
+// BCH-01-009: Proper error classification to distinguish expected states from critical failures
+
+/// Result of a keychain read operation with proper error classification
+enum KeychainReadResult {
+    case success(Data)
+    case itemNotFound        // Expected: key doesn't exist yet
+    case accessDenied        // Critical: app lacks keychain access
+    case deviceLocked        // Recoverable: device is locked
+    case authenticationFailed // Recoverable: biometric/passcode failed
+    case otherError(OSStatus) // Unexpected error
+
+    var isRecoverableError: Bool {
+        switch self {
+        case .deviceLocked, .authenticationFailed:
+            return true
+        default:
+            return false
+        }
+    }
+}
+
+/// Result of a keychain save operation with proper error classification
+enum KeychainSaveResult {
+    case success
+    case duplicateItem       // Can retry with update
+    case accessDenied        // Critical: app lacks keychain access
+    case deviceLocked        // Recoverable: device is locked
+    case storageFull         // Critical: no space available
+    case otherError(OSStatus)
+
+    var isRecoverableError: Bool {
+        switch self {
+        case .duplicateItem, .deviceLocked:
+            return true
+        default:
+            return false
+        }
+    }
+}
+
 protocol KeychainManagerProtocol {
    func saveIdentityKey(_ keyData: Data, forKey key: String) -> Bool
    func getIdentityKey(forKey key: String) -> Data?
    func deleteIdentityKey(forKey key: String) -> Bool
    func deleteAllKeychainData() -> Bool
-    
+
    func secureClear(_ data: inout Data)
    func secureClear(_ string: inout String)
-    
+
    func verifyIdentityKeyExists() -> Bool
+
+    // BCH-01-009: Methods with proper error classification
+    /// Get identity key with detailed result for error handling
+    func getIdentityKeyWithResult(forKey key: String) -> KeychainReadResult
+    /// Save identity key with detailed result for error handling
+    func saveIdentityKeyWithResult(_ keyData: Data, forKey key: String) -> KeychainSaveResult
+
+    // MARK: - Generic Data Storage (consolidated from KeychainHelper)
+    /// Save data with a custom service name
+    func save(key: String, data: Data, service: String, accessible: CFString?)
+    /// Load data from a custom service
+    func load(key: String, service: String) -> Data?
+    /// Delete data from a custom service
+    func delete(key: String, service: String)
 }

 final class KeychainManager: KeychainManagerProtocol {
@@ -27,34 +82,6 @@ final class KeychainManager: KeychainManagerProtocol {
    private let service = BitchatApp.bundleID
    private let appGroup = "group.\(BitchatApp.bundleID)"
    
-    private func isSandboxed() -> Bool {
-        #if os(macOS)
-        // More robust sandbox detection using multiple methods
-        
-        // Method 1: Check environment variable (can be spoofed)
-        let environment = ProcessInfo.processInfo.environment
-        let hasEnvVar = environment["APP_SANDBOX_CONTAINER_ID"] != nil
-        
-        // Method 2: Check if we can access a path outside sandbox
-        let homeDir = FileManager.default.homeDirectoryForCurrentUser
-        let testPath = homeDir.appendingPathComponent("../../../tmp/bitchat_sandbox_test_\(UUID().uuidString)")
-        let canWriteOutsideSandbox = FileManager.default.createFile(atPath: testPath.path, contents: nil, attributes: nil)
-        if canWriteOutsideSandbox {
-            try? FileManager.default.removeItem(at: testPath)
-        }
-        
-        // Method 3: Check container path
-        let containerPath = FileManager.default.urls(for: .libraryDirectory, in: .userDomainMask).first?.path ?? ""
-        let hasContainerPath = containerPath.contains("/Containers/")
-        
-        // If any method indicates sandbox, we consider it sandboxed
-        return hasEnvVar || !canWriteOutsideSandbox || hasContainerPath
-        #else
-        // iOS is always sandboxed
-        return true
-        #endif
-    }
-    
    // MARK: - Identity Keys
    
    func saveIdentityKey(_ keyData: Data, forKey key: String) -> Bool {
@@ -74,7 +101,181 @@ final class KeychainManager: KeychainManagerProtocol {
        SecureLogger.logKeyOperation(.delete, keyType: key, success: result)
        return result
    }
-    
+
+    // MARK: - BCH-01-009: Methods with Proper Error Classification
+
+    /// Get identity key with detailed result for proper error handling
+    /// Distinguishes between missing keys (expected) and critical failures
+    func getIdentityKeyWithResult(forKey key: String) -> KeychainReadResult {
+        let fullKey = "identity_\(key)"
+        return retrieveDataWithResult(forKey: fullKey)
+    }
+
+    /// Save identity key with detailed result and retry logic for transient errors
+    func saveIdentityKeyWithResult(_ keyData: Data, forKey key: String) -> KeychainSaveResult {
+        let fullKey = "identity_\(key)"
+        return saveDataWithResult(keyData, forKey: fullKey)
+    }
+
+    /// Internal method to save data with detailed result and retry for transient errors
+    private func saveDataWithResult(_ data: Data, forKey key: String, retryCount: Int = 2) -> KeychainSaveResult {
+        // Delete any existing item first to ensure clean state
+        _ = delete(forKey: key)
+
+        // Build base query
+        var base: [String: Any] = [
+            kSecClass as String: kSecClassGenericPassword,
+            kSecAttrAccount as String: key,
+            kSecValueData as String: data,
+            kSecAttrService as String: service,
+            kSecAttrAccessible as String: kSecAttrAccessibleWhenUnlocked,
+            kSecAttrLabel as String: "bitchat-\(key)"
+        ]
+        #if os(macOS)
+        base[kSecAttrSynchronizable as String] = false
+        #endif
+
+        func attempt(addAccessGroup: Bool) -> OSStatus {
+            var query = base
+            if addAccessGroup { query[kSecAttrAccessGroup as String] = appGroup }
+            return SecItemAdd(query as CFDictionary, nil)
+        }
+
+        #if os(iOS)
+        var status = attempt(addAccessGroup: true)
+        if status == -34018 { // Missing entitlement, retry without access group
+            status = attempt(addAccessGroup: false)
+        }
+        #else
+        let status = attempt(addAccessGroup: false)
+        #endif
+
+        // Classify the result
+        let result = classifySaveStatus(status)
+
+        // Log all outcomes consistently
+        switch result {
+        case .success:
+            SecureLogger.debug("Keychain save succeeded for key: \(key)", category: .keychain)
+        case .duplicateItem:
+            SecureLogger.warning("Keychain save found duplicate for key: \(key)", category: .keychain)
+        case .accessDenied:
+            SecureLogger.error(NSError(domain: "Keychain", code: Int(status)),
+                               context: "Keychain access denied for key: \(key)", category: .keychain)
+        case .deviceLocked:
+            SecureLogger.warning("Device locked during keychain save for key: \(key)", category: .keychain)
+        case .storageFull:
+            SecureLogger.error(NSError(domain: "Keychain", code: Int(status)),
+                               context: "Keychain storage full for key: \(key)", category: .keychain)
+        case .otherError(let code):
+            SecureLogger.error(NSError(domain: "Keychain", code: Int(code)),
+                               context: "Keychain save failed for key: \(key)", category: .keychain)
+        }
+
+        // Retry transient errors with exponential backoff
+        if result.isRecoverableError && retryCount > 0 {
+            let delayMs = UInt32((3 - retryCount) * 100) // 100ms, 200ms backoff
+            usleep(delayMs * 1000)
+            SecureLogger.debug("Retrying keychain save for key: \(key), attempts remaining: \(retryCount)", category: .keychain)
+            return saveDataWithResult(data, forKey: key, retryCount: retryCount - 1)
+        }
+
+        return result
+    }
+
+    /// Internal method to retrieve data with detailed result
+    private func retrieveDataWithResult(forKey key: String) -> KeychainReadResult {
+        let base: [String: Any] = [
+            kSecClass as String: kSecClassGenericPassword,
+            kSecAttrAccount as String: key,
+            kSecAttrService as String: service,
+            kSecReturnData as String: true,
+            kSecMatchLimit as String: kSecMatchLimitOne
+        ]
+
+        var result: AnyObject?
+        func attempt(withAccessGroup: Bool) -> OSStatus {
+            var q = base
+            if withAccessGroup { q[kSecAttrAccessGroup as String] = appGroup }
+            return SecItemCopyMatching(q as CFDictionary, &result)
+        }
+
+        #if os(iOS)
+        var status = attempt(withAccessGroup: true)
+        if status == -34018 { status = attempt(withAccessGroup: false) }
+        #else
+        let status = attempt(withAccessGroup: false)
+        #endif
+
+        // Classify the result
+        let readResult = classifyReadStatus(status, data: result as? Data)
+
+        // Log all outcomes consistently
+        switch readResult {
+        case .success:
+            SecureLogger.debug("Keychain read succeeded for key: \(key)", category: .keychain)
+        case .itemNotFound:
+            // Expected case - no logging needed for missing keys
+            break
+        case .accessDenied:
+            SecureLogger.error(NSError(domain: "Keychain", code: Int(status)),
+                               context: "Keychain access denied for key: \(key)", category: .keychain)
+        case .deviceLocked:
+            SecureLogger.warning("Device locked during keychain read for key: \(key)", category: .keychain)
+        case .authenticationFailed:
+            SecureLogger.warning("Authentication failed for keychain read of key: \(key)", category: .keychain)
+        case .otherError(let code):
+            SecureLogger.error(NSError(domain: "Keychain", code: Int(code)),
+                               context: "Keychain read failed for key: \(key)", category: .keychain)
+        }
+
+        return readResult
+    }
+
+    /// Classify keychain read status into meaningful categories
+    private func classifyReadStatus(_ status: OSStatus, data: Data?) -> KeychainReadResult {
+        switch status {
+        case errSecSuccess:
+            if let data = data {
+                return .success(data)
+            }
+            return .otherError(status)
+        case errSecItemNotFound:
+            return .itemNotFound
+        case errSecInteractionNotAllowed:
+            // Device is locked or in a state that doesn't allow keychain access
+            return .deviceLocked
+        case errSecAuthFailed:
+            return .authenticationFailed
+        case -34018: // errSecMissingEntitlement
+            return .accessDenied
+        case errSecNotAvailable:
+            return .accessDenied
+        default:
+            return .otherError(status)
+        }
+    }
+
+    /// Classify keychain save status into meaningful categories
+    private func classifySaveStatus(_ status: OSStatus) -> KeychainSaveResult {
+        switch status {
+        case errSecSuccess:
+            return .success
+        case errSecDuplicateItem:
+            return .duplicateItem
+        case errSecInteractionNotAllowed:
+            return .deviceLocked
+        case -34018: // errSecMissingEntitlement
+            return .accessDenied
+        case errSecNotAvailable:
+            return .accessDenied
+        case errSecDiskFull:
+            return .storageFull
+        default:
+            return .otherError(status)
+        }
+    }
+
    // MARK: - Generic Operations
    
    private func save(_ value: String, forKey key: String) -> Bool {
@@ -337,9 +538,54 @@ final class KeychainManager: KeychainManagerProtocol {
    }
    
    // MARK: - Debug
-    
+
    func verifyIdentityKeyExists() -> Bool {
        let key = "identity_noiseStaticKey"
        return retrieveData(forKey: key) != nil
    }
+
+    // MARK: - Generic Data Storage (consolidated from KeychainHelper)
+
+    /// Save data with a custom service name
+    func save(key: String, data: Data, service customService: String, accessible: CFString?) {
+        var query: [String: Any] = [
+            kSecClass as String: kSecClassGenericPassword,
+            kSecAttrService as String: customService,
+            kSecAttrAccount as String: key,
+            kSecValueData as String: data
+        ]
+        if let accessible = accessible {
+            query[kSecAttrAccessible as String] = accessible
+        }
+
+        SecItemDelete(query as CFDictionary)
+        SecItemAdd(query as CFDictionary, nil)
+    }
+
+    /// Load data from a custom service
+    func load(key: String, service customService: String) -> Data? {
+        let query: [String: Any] = [
+            kSecClass as String: kSecClassGenericPassword,
+            kSecAttrService as String: customService,
+            kSecAttrAccount as String: key,
+            kSecReturnData as String: true
+        ]
+
+        var result: AnyObject?
+        let status = SecItemCopyMatching(query as CFDictionary, &result)
+
+        guard status == errSecSuccess else { return nil }
+        return result as? Data
+    }
+
+    /// Delete data from a custom service
+    func delete(key: String, service customService: String) {
+        let query: [String: Any] = [
+            kSecClass as String: kSecClassGenericPassword,
+            kSecAttrService as String: customService,
+            kSecAttrAccount as String: key
+        ]
+
+        SecItemDelete(query as CFDictionary)
+    }
 }
@@ -1,304 +0,0 @@
-import BitLogger
-import Foundation
-import Combine
-
-#if os(iOS) || os(macOS)
-import CoreLocation
-
-/// Manages location permissions, one-shot location retrieval, and computing geohash channels.
-/// Not main-actor isolated to satisfy CLLocationManagerDelegate in Swift 6; state updates hop to MainActor.
-final class LocationChannelManager: NSObject, CLLocationManagerDelegate, ObservableObject {
-    static let shared = LocationChannelManager()
-
-    enum PermissionState: Equatable {
-        case notDetermined
-        case denied
-        case restricted
-        case authorized
-    }
-
-    private let cl = CLLocationManager()
-    private let geocoder = CLGeocoder()
-    private var lastLocation: CLLocation?
-    private var refreshTimer: Timer?
-    private let userDefaultsKey = "locationChannel.selected"
-    private let teleportedStoreKey = "locationChannel.teleportedSet"
-    private var isGeocoding: Bool = false
-
-    // Published state for UI bindings
-    @Published private(set) var permissionState: PermissionState = .notDetermined
-    @Published private(set) var availableChannels: [GeohashChannel] = []
-    @Published private(set) var selectedChannel: ChannelID = .mesh
-    // True when the current location channel was selected via manual teleport
-    @Published var teleported: Bool = false
-    @Published private(set) var locationNames: [GeohashChannelLevel: String] = [:]
-
-    // Persisted set of geohashes that were selected via teleport
-    private var teleportedSet: Set<String> = []
-
-    private override init() {
-        super.init()
-        cl.delegate = self
-        cl.desiredAccuracy = kCLLocationAccuracyHundredMeters
-        cl.distanceFilter = TransportConfig.locationDistanceFilterMeters // meters; we're not tracking continuously
-        // Load selection
-        if let data = UserDefaults.standard.data(forKey: userDefaultsKey),
-           let channel = try? JSONDecoder().decode(ChannelID.self, from: data) {
-            selectedChannel = channel
-        }
-        // Load persisted teleported set
-        if let data = UserDefaults.standard.data(forKey: teleportedStoreKey),
-           let arr = try? JSONDecoder().decode([String].self, from: data) {
-            teleportedSet = Set(arr)
-        }
-        // Do not eagerly mark teleported on startup; wait for location to compute regional set.
-        // This avoids showing teleported for in-region channels during cold start.
-        let status: CLAuthorizationStatus
-        if #available(iOS 14.0, macOS 11.0, *) {
-            status = cl.authorizationStatus
-        } else {
-            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
-    func enableLocationChannels() {
-        let status: CLAuthorizationStatus
-        if #available(iOS 14.0, macOS 11.0, *) {
-            status = cl.authorizationStatus
-        } else {
-            status = CLLocationManager.authorizationStatus()
-        }
-        switch status {
-        case .notDetermined:
-            cl.requestWhenInUseAuthorization()
-        case .restricted:
-            Task { @MainActor in self.permissionState = .restricted }
-        case .denied:
-            Task { @MainActor in self.permissionState = .denied }
-        case .authorizedAlways, .authorizedWhenInUse, .authorized:
-            Task { @MainActor in self.permissionState = .authorized }
-            requestOneShotLocation()
-        @unknown default:
-            Task { @MainActor in self.permissionState = .restricted }
-        }
-    }
-
-    func refreshChannels() {
-        if permissionState == .authorized {
-            requestOneShotLocation()
-        }
-    }
-
-    /// Begin continuous, distance-filtered updates while the channel sheet is visible.
-    /// Uses a 21m filter (configurable) to only refresh on meaningful movement.
-    func beginLiveRefresh(interval: TimeInterval = TransportConfig.locationLiveRefreshInterval) {
-        guard permissionState == .authorized else { return }
-        // Stop any previous polling timer
-        refreshTimer?.invalidate()
-        refreshTimer = nil
-        // Tighten accuracy and distance filter for live view
-        cl.desiredAccuracy = kCLLocationAccuracyNearestTenMeters
-        cl.distanceFilter = TransportConfig.locationDistanceFilterLiveMeters
-        // Start continuous updates
-        cl.startUpdatingLocation()
-        // Request an immediate fix to populate UI without waiting for movement
-        requestOneShotLocation()
-    }
-
-    /// Stop continuous refreshes when selector UI is dismissed.
-    func endLiveRefresh() {
-        refreshTimer?.invalidate()
-        refreshTimer = nil
-        cl.stopUpdatingLocation()
-        // Restore more relaxed defaults for background/idle state
-        cl.desiredAccuracy = kCLLocationAccuracyHundredMeters
-        cl.distanceFilter = TransportConfig.locationDistanceFilterMeters
-    }
-
-    func select(_ channel: ChannelID) {
-        Task { @MainActor in
-            self.selectedChannel = channel
-            if let data = try? JSONEncoder().encode(channel) {
-                UserDefaults.standard.set(data, forKey: self.userDefaultsKey)
-            }
-            // Update teleported flag based on persisted state for immediate UI behavior
-            switch channel {
-            case .mesh:
-                self.teleported = false
-            case .location(let ch):
-                // 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)
-                }
-            }
-        }
-    }
-
-    // Mark or unmark a geohash as teleported in persistence and update current flag if relevant
-    func markTeleported(for geohash: String, _ flag: Bool) {
-        if flag { teleportedSet.insert(geohash) } else { teleportedSet.remove(geohash) }
-        if let data = try? JSONEncoder().encode(Array(teleportedSet)) {
-            UserDefaults.standard.set(data, forKey: teleportedStoreKey)
-        }
-        if case .location(let ch) = selectedChannel, ch.geohash == geohash {
-            Task { @MainActor in self.teleported = flag }
-        }
-    }
-
-    // MARK: - CoreLocation
-    private func requestOneShotLocation() {
-        cl.requestLocation()
-    }
-
-    // iOS < 14
-    func locationManager(_ manager: CLLocationManager, didChangeAuthorization status: CLAuthorizationStatus) {
-        updatePermissionState(from: status)
-        if case .authorized = permissionState {
-            requestOneShotLocation()
-        }
-    }
-
-    // iOS 14+ / macOS 11+
-    @available(iOS 14.0, macOS 11.0, *)
-    func locationManagerDidChangeAuthorization(_ manager: CLLocationManager) {
-        updatePermissionState(from: manager.authorizationStatus)
-        if case .authorized = permissionState {
-            requestOneShotLocation()
-        }
-    }
-
-    func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
-        guard let loc = locations.last else { return }
-        lastLocation = loc
-        computeChannels(from: loc.coordinate)
-        reverseGeocodeIfNeeded(location: loc)
-    }
-
-    func locationManager(_ manager: CLLocationManager, didFailWithError error: Error) {
-        // Surface as denied/restricted if relevant; otherwise keep previous state
-        SecureLogger.error("LocationChannelManager: location error: \(error.localizedDescription)", category: .session)
-    }
-
-    // MARK: - Helpers
-    private func updatePermissionState(from status: CLAuthorizationStatus) {
-        let newState: PermissionState
-        switch status {
-        case .notDetermined: newState = .notDetermined
-        case .restricted: newState = .restricted
-        case .denied: newState = .denied
-        case .authorizedAlways, .authorizedWhenInUse, .authorized: newState = .authorized
-        @unknown default: newState = .restricted
-        }
-        Task { @MainActor in self.permissionState = newState }
-    }
-
-    private func computeChannels(from coord: CLLocationCoordinate2D) {
-        let levels = GeohashChannelLevel.allCases
-        var result: [GeohashChannel] = []
-        for level in levels {
-            let gh = Geohash.encode(latitude: coord.latitude, longitude: coord.longitude, precision: level.precision)
-            result.append(GeohashChannel(level: level, geohash: gh))
-        }
-        Task { @MainActor in
-            self.availableChannels = result
-            // 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):
-                // Membership check using freshly computed regional channels; avoids precision/rename drift
-                let inRegional = result.contains { $0.geohash == 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
-                }
-            }
-        }
-    }
-
-    private func reverseGeocodeIfNeeded(location: CLLocation) {
-        // Always cancel previous to keep latest fresh while user moves
-        geocoder.cancelGeocode()
-        isGeocoding = true
-        geocoder.reverseGeocodeLocation(location) { [weak self] placemarks, error in
-            guard let self = self else { return }
-            self.isGeocoding = false
-            if let pm = placemarks?.first {
-                let names = self.namesByLevel(from: pm)
-                Task { @MainActor in self.locationNames = names }
-            }
-        }
-    }
-
-    private func namesByLevel(from pm: CLPlacemark) -> [GeohashChannelLevel: String] {
-        var dict: [GeohashChannelLevel: String] = [:]
-        // Region (country)
-        if let country = pm.country, !country.isEmpty {
-            dict[.region] = country
-        }
-        // Province (state/province or county)
-        if let admin = pm.administrativeArea, !admin.isEmpty {
-            dict[.province] = admin
-        } else if let subAdmin = pm.subAdministrativeArea, !subAdmin.isEmpty {
-            dict[.province] = subAdmin
-        }
-        // City (locality)
-        if let locality = pm.locality, !locality.isEmpty {
-            dict[.city] = locality
-        } else if let subAdmin = pm.subAdministrativeArea, !subAdmin.isEmpty {
-            dict[.city] = subAdmin
-        } else if let admin = pm.administrativeArea, !admin.isEmpty {
-            dict[.city] = admin
-        }
-        // Neighborhood
-        if let subLocality = pm.subLocality, !subLocality.isEmpty {
-            dict[.neighborhood] = subLocality
-        } else if let locality = pm.locality, !locality.isEmpty {
-            dict[.neighborhood] = locality
-        }
-        // Block: reuse neighborhood/locality granularity
-        if let subLocality = pm.subLocality, !subLocality.isEmpty {
-            dict[.block] = subLocality
-        } else if let locality = pm.locality, !locality.isEmpty {
-            dict[.block] = locality
-        }
-        // Building: prefer place name/street/venue when available
-        if let name = pm.name, !name.isEmpty {
-            dict[.building] = name
-        } else if let thoroughfare = pm.thoroughfare, !thoroughfare.isEmpty {
-            dict[.building] = thoroughfare
-        }
-        return dict
-    }
-}
-#endif
@@ -1,104 +0,0 @@
-import BitLogger
-import Foundation
-
-struct LocationNotesCounterDependencies {
-    typealias RelayLookup = @MainActor (_ geohash: String, _ count: Int) -> [String]
-    typealias Subscribe = @MainActor (_ filter: NostrFilter, _ id: String, _ relays: [String], _ handler: @escaping (NostrEvent) -> Void, _ onEOSE: (() -> Void)?) -> Void
-    typealias Unsubscribe = @MainActor (_ id: String) -> Void
-
-    var relayLookup: RelayLookup
-    var subscribe: Subscribe
-    var unsubscribe: Unsubscribe
-
-    static let live = LocationNotesCounterDependencies(
-        relayLookup: { geohash, count in
-            GeoRelayDirectory.shared.closestRelays(toGeohash: geohash, count: count)
-        },
-        subscribe: { filter, id, relays, handler, onEOSE in
-            NostrRelayManager.shared.subscribe(
-                filter: filter,
-                id: id,
-                relayUrls: relays,
-                handler: handler,
-                onEOSE: onEOSE
-            )
-        },
-        unsubscribe: { id in
-            NostrRelayManager.shared.unsubscribe(id: id)
-        }
-    )
-}
-
-/// Lightweight background counter for location notes (kind 1) at building-level geohash (8 chars).
-@MainActor
-final class LocationNotesCounter: ObservableObject {
-    static let shared = LocationNotesCounter()
-
-    @Published private(set) var geohash: String? = nil
-    @Published private(set) var count: Int? = 0
-    @Published private(set) var initialLoadComplete: Bool = false
-    @Published private(set) var relayAvailable: Bool = true
-
-    private var subscriptionID: String? = nil
-    private var noteIDs = Set<String>()
-    private let dependencies: LocationNotesCounterDependencies
-
-    private init(dependencies: LocationNotesCounterDependencies = .live) {
-        self.dependencies = dependencies
-    }
-
-    init(testDependencies: LocationNotesCounterDependencies) {
-        self.dependencies = testDependencies
-    }
-
-    func subscribe(geohash gh: String) {
-        let norm = gh.lowercased()
-        if geohash == norm, subscriptionID != nil { return }
-        // Validate geohash (building-level precision: 8 chars)
-        guard Geohash.isValidBuildingGeohash(norm) else {
-            SecureLogger.warning("LocationNotesCounter: rejecting invalid geohash '\(norm)' (expected 8 valid base32 chars)", category: .session)
-            return
-        }
-        // Unsubscribe previous without clearing count to avoid flicker
-        if let sub = subscriptionID { dependencies.unsubscribe(sub) }
-        subscriptionID = nil
-        geohash = norm
-        noteIDs.removeAll()
-        initialLoadComplete = false
-        relayAvailable = true
-
-        // Subscribe only to the building geohash (precision 8)
-        let subID = "locnotes-count-\(norm)-\(UUID().uuidString.prefix(6))"
-        let relays = dependencies.relayLookup(norm, TransportConfig.nostrGeoRelayCount)
-        guard !relays.isEmpty else {
-            relayAvailable = false
-            initialLoadComplete = true
-            count = 0
-            SecureLogger.warning("LocationNotesCounter: no geo relays for geohash=\(norm)", category: .session)
-            return
-        }
-
-        subscriptionID = subID
-        let filter = NostrFilter.geohashNotes(norm, since: nil, limit: 200)
-        dependencies.subscribe(filter, subID, relays, { [weak self] event in
-            guard let self = self else { return }
-            guard event.kind == NostrProtocol.EventKind.textNote.rawValue else { return }
-            guard event.tags.contains(where: { $0.count >= 2 && $0[0].lowercased() == "g" && $0[1].lowercased() == norm }) else { return }
-            if !self.noteIDs.contains(event.id) {
-                self.noteIDs.insert(event.id)
-                self.count = self.noteIDs.count
-            }
-        }, { [weak self] in
-            self?.initialLoadComplete = true
-        })
-    }
-
-    func cancel() {
-        if let sub = subscriptionID { dependencies.unsubscribe(sub) }
-        subscriptionID = nil
-        geohash = nil
-        count = 0
-        noteIDs.removeAll()
-        relayAvailable = true
-    }
-}
@@ -14,6 +14,8 @@ struct LocationNotesDependencies {
    var sendEvent: SendEvent
    var deriveIdentity: (_ geohash: String) throws -> NostrIdentity
    var now: () -> Date
+    
+    private static let idBridge = NostrIdentityBridge()

    static let live = LocationNotesDependencies(
        relayLookup: { geohash, count in
@@ -35,7 +37,7 @@ struct LocationNotesDependencies {
            NostrRelayManager.shared.sendEvent(event, to: relays)
        },
        deriveIdentity: { geohash in
-            try NostrIdentityBridge.deriveIdentity(forGeohash: geohash)
+            try idBridge.deriveIdentity(forGeohash: geohash)
        },
        now: { Date() }
    )
@@ -61,7 +63,7 @@ final class LocationNotesManager: ObservableObject {

        var displayName: String {
            let suffix = String(pubkey.suffix(4))
-            if let nick = nickname, !nick.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty {
+            if let nick = nickname?.trimmedOrNilIfEmpty {
                return "\(nick)#\(suffix)"
            }
            return "anon#\(suffix)"
@@ -161,14 +163,22 @@ final class LocationNotesManager: ObservableObject {

        subscriptionID = subID
        initialLoadComplete = false
-        // For persistent notes, allow relays to return recent history without an aggressive time cutoff
-        let filter = NostrFilter.geohashNotes(geohash, since: nil, limit: 200)
+
+        // Subscribe to center + 8 neighbors (± 1 grid)
+        let neighbors = Geohash.neighbors(of: geohash)
+        let allGeohashes = [geohash] + neighbors
+        let filter = NostrFilter.geohashNotes(allGeohashes, since: nil, limit: 200)
+
+        // Build a set of valid geohashes for tag matching (includes all 9 cells)
+        let validGeohashes = Set(allGeohashes.map { $0.lowercased() })

        dependencies.subscribe(filter, subID, relays, { [weak self] event in
            guard let self = self else { return }
            guard event.kind == NostrProtocol.EventKind.textNote.rawValue else { return }
-            // Ensure matching tag
-            guard event.tags.contains(where: { $0.count >= 2 && $0[0].lowercased() == "g" && $0[1].lowercased() == self.geohash }) else { return }
+            // Ensure matching tag - accept any of our 9 geohashes
+            guard event.tags.contains(where: { tag in
+                tag.count >= 2 && tag[0].lowercased() == "g" && validGeohashes.contains(tag[1].lowercased())
+            }) else { return }
            guard !self.noteIDs.contains(event.id) else { return }
            self.noteIDs.insert(event.id)
            let nick = event.tags.first(where: { $0.first?.lowercased() == "n" && $0.count >= 2 })?.dropFirst().first
@@ -189,8 +199,7 @@ final class LocationNotesManager: ObservableObject {

    /// Send a location note for the current geohash using the per-geohash identity.
    func send(content: String, nickname: String) {
-        let trimmed = content.trimmingCharacters(in: .whitespacesAndNewlines)
-        guard !trimmed.isEmpty else { return }
+        guard let trimmed = content.trimmedOrNilIfEmpty else { return }
        let relays = dependencies.relayLookup(geohash, TransportConfig.nostrGeoRelayCount)
        guard !relays.isEmpty else {
            state = .noRelays
@@ -0,0 +1,630 @@
+import BitLogger
+import Foundation
+import Combine
+
+#if os(iOS) || os(macOS)
+import CoreLocation
+
+protocol LocationStateManaging: AnyObject {
+    var delegate: CLLocationManagerDelegate? { get set }
+    var desiredAccuracy: CLLocationAccuracy { get set }
+    var distanceFilter: CLLocationDistance { get set }
+    var authorizationStatus: CLAuthorizationStatus { get }
+    func requestWhenInUseAuthorization()
+    func requestLocation()
+    func startUpdatingLocation()
+    func stopUpdatingLocation()
+}
+
+protocol LocationStateGeocoding: AnyObject {
+    func cancelGeocode()
+    func reverseGeocodeLocation(
+        _ location: CLLocation,
+        completionHandler: @escaping ([CLPlacemark]?, Error?) -> Void
+    )
+}
+
+private final class CLLocationManagerAdapter: NSObject, LocationStateManaging {
+    private let base = CLLocationManager()
+
+    var delegate: CLLocationManagerDelegate? {
+        get { base.delegate }
+        set { base.delegate = newValue }
+    }
+
+    var desiredAccuracy: CLLocationAccuracy {
+        get { base.desiredAccuracy }
+        set { base.desiredAccuracy = newValue }
+    }
+
+    var distanceFilter: CLLocationDistance {
+        get { base.distanceFilter }
+        set { base.distanceFilter = newValue }
+    }
+
+    var authorizationStatus: CLAuthorizationStatus {
+        base.authorizationStatus
+    }
+
+    func requestWhenInUseAuthorization() {
+        base.requestWhenInUseAuthorization()
+    }
+
+    func requestLocation() {
+        base.requestLocation()
+    }
+
+    func startUpdatingLocation() {
+        base.startUpdatingLocation()
+    }
+
+    func stopUpdatingLocation() {
+        base.stopUpdatingLocation()
+    }
+}
+
+private final class CLGeocoderAdapter: LocationStateGeocoding {
+    private let base = CLGeocoder()
+
+    func cancelGeocode() {
+        base.cancelGeocode()
+    }
+
+    func reverseGeocodeLocation(
+        _ location: CLLocation,
+        completionHandler: @escaping ([CLPlacemark]?, Error?) -> Void
+    ) {
+        base.reverseGeocodeLocation(location, completionHandler: completionHandler)
+    }
+}
+
+/// Unified manager for location-based channel state including:
+/// - CoreLocation permissions and one-shot location retrieval
+/// - Geohash channel computation from coordinates
+/// - Channel selection and teleport state
+/// - Bookmark persistence and friendly name resolution
+///
+/// Consolidates LocationChannelManager + GeohashBookmarksStore into a single source of truth.
+final class LocationStateManager: NSObject, CLLocationManagerDelegate, ObservableObject {
+    static let shared = LocationStateManager()
+
+    // MARK: - Permission State
+
+    enum PermissionState: Equatable {
+        case notDetermined
+        case denied
+        case restricted
+        case authorized
+    }
+
+    // MARK: - Private Properties (CoreLocation)
+
+    private let cl: LocationStateManaging
+    private let geocoder: LocationStateGeocoding
+    private var lastLocation: CLLocation?
+    private var refreshTimer: Timer?
+    private var isGeocoding: Bool = false
+
+    // MARK: - Persistence Keys
+
+    private let selectedChannelKey = "locationChannel.selected"
+    private let teleportedStoreKey = "locationChannel.teleportedSet"
+    private let bookmarksKey = "locationChannel.bookmarks"
+    private let bookmarkNamesKey = "locationChannel.bookmarkNames"
+
+    // MARK: - Published State (Channel)
+
+    @Published private(set) var permissionState: PermissionState = .notDetermined
+    @Published private(set) var availableChannels: [GeohashChannel] = []
+    @Published private(set) var selectedChannel: ChannelID = .mesh
+    @Published var teleported: Bool = false
+    @Published private(set) var locationNames: [GeohashChannelLevel: String] = [:]
+
+    // MARK: - Published State (Bookmarks)
+
+    @Published private(set) var bookmarks: [String] = []
+    @Published private(set) var bookmarkNames: [String: String] = [:]
+
+    // MARK: - Private State
+
+    private var teleportedSet: Set<String> = []
+    private var bookmarkMembership: Set<String> = []
+    private var resolvingNames: Set<String> = []
+    private let storage: UserDefaults
+
+    /// Returns true if running in test environment
+    private static var isRunningTests: Bool {
+        let env = ProcessInfo.processInfo.environment
+        return NSClassFromString("XCTestCase") != nil ||
+               env["XCTestConfigurationFilePath"] != nil ||
+               env["XCTestBundlePath"] != nil ||
+               env["GITHUB_ACTIONS"] != nil ||
+               env["CI"] != nil
+    }
+
+    // MARK: - Initialization
+
+    private override init() {
+        self.storage = .standard
+        self.cl = CLLocationManagerAdapter()
+        self.geocoder = CLGeocoderAdapter()
+        super.init()
+
+        // Skip CoreLocation setup in test environments
+        guard !Self.isRunningTests else {
+            loadPersistedState()
+            return
+        }
+
+        cl.delegate = self
+        cl.desiredAccuracy = kCLLocationAccuracyHundredMeters
+        cl.distanceFilter = TransportConfig.locationDistanceFilterMeters
+
+        loadPersistedState()
+        initializePermissionState()
+    }
+
+    /// Internal initializer for testing with custom storage
+    init(storage: UserDefaults) {
+        self.storage = storage
+        self.cl = CLLocationManagerAdapter()
+        self.geocoder = CLGeocoderAdapter()
+        super.init()
+        loadPersistedState()
+    }
+
+    internal init(
+        storage: UserDefaults,
+        locationManager: LocationStateManaging,
+        geocoder: LocationStateGeocoding,
+        shouldInitializeCoreLocation: Bool
+    ) {
+        self.storage = storage
+        self.cl = locationManager
+        self.geocoder = geocoder
+        super.init()
+        loadPersistedState()
+        guard shouldInitializeCoreLocation else { return }
+        cl.delegate = self
+        cl.desiredAccuracy = kCLLocationAccuracyHundredMeters
+        cl.distanceFilter = TransportConfig.locationDistanceFilterMeters
+        initializePermissionState()
+    }
+
+    private func loadPersistedState() {
+        // Load selected channel
+        if let data = storage.data(forKey: selectedChannelKey),
+           let channel = try? JSONDecoder().decode(ChannelID.self, from: data) {
+            selectedChannel = channel
+        }
+
+        // Load teleported set
+        if let data = storage.data(forKey: teleportedStoreKey),
+           let arr = try? JSONDecoder().decode([String].self, from: data) {
+            teleportedSet = Set(arr)
+        }
+
+        // Load bookmarks
+        if let data = storage.data(forKey: bookmarksKey),
+           let arr = try? JSONDecoder().decode([String].self, from: data) {
+            var seen = Set<String>()
+            var list: [String] = []
+            for raw in arr {
+                let gh = Self.normalizeGeohash(raw)
+                guard !gh.isEmpty, !seen.contains(gh) else { continue }
+                seen.insert(gh)
+                list.append(gh)
+            }
+            bookmarks = list
+            bookmarkMembership = seen
+        }
+
+        // Load bookmark names
+        if let data = storage.data(forKey: bookmarkNamesKey),
+           let dict = try? JSONDecoder().decode([String: String].self, from: data) {
+            bookmarkNames = dict
+        }
+    }
+
+    private func initializePermissionState() {
+        let status = cl.authorizationStatus
+        updatePermissionState(from: status)
+
+        // Fall back to persisted teleport state if no location authorization
+        switch status {
+        case .authorizedAlways, .authorizedWhenInUse, .authorized:
+            break
+        case .notDetermined, .restricted, .denied:
+            fallthrough
+        @unknown default:
+            if case .location(let ch) = selectedChannel {
+                teleported = teleportedSet.contains(ch.geohash)
+            }
+        }
+    }
+
+    // MARK: - Public API (Permissions & Location)
+
+    func enableLocationChannels() {
+        let status = cl.authorizationStatus
+        switch status {
+        case .notDetermined:
+            cl.requestWhenInUseAuthorization()
+        case .restricted:
+            Task { @MainActor in self.permissionState = .restricted }
+        case .denied:
+            Task { @MainActor in self.permissionState = .denied }
+        case .authorizedAlways, .authorizedWhenInUse, .authorized:
+            Task { @MainActor in self.permissionState = .authorized }
+            requestOneShotLocation()
+        @unknown default:
+            Task { @MainActor in self.permissionState = .restricted }
+        }
+    }
+
+    func refreshChannels() {
+        if permissionState == .authorized {
+            requestOneShotLocation()
+        }
+    }
+
+    func beginLiveRefresh(interval: TimeInterval = TransportConfig.locationLiveRefreshInterval) {
+        guard permissionState == .authorized else { return }
+        refreshTimer?.invalidate()
+        refreshTimer = nil
+        cl.desiredAccuracy = kCLLocationAccuracyNearestTenMeters
+        cl.distanceFilter = TransportConfig.locationDistanceFilterLiveMeters
+        cl.startUpdatingLocation()
+        requestOneShotLocation()
+    }
+
+    func endLiveRefresh() {
+        refreshTimer?.invalidate()
+        refreshTimer = nil
+        cl.stopUpdatingLocation()
+        cl.desiredAccuracy = kCLLocationAccuracyHundredMeters
+        cl.distanceFilter = TransportConfig.locationDistanceFilterMeters
+    }
+
+    // MARK: - Public API (Channel Selection)
+
+    func select(_ channel: ChannelID) {
+        Task { @MainActor in
+            self.selectedChannel = channel
+            if let data = try? JSONEncoder().encode(channel) {
+                self.storage.set(data, forKey: self.selectedChannelKey)
+            }
+
+            switch channel {
+            case .mesh:
+                self.teleported = false
+            case .location(let ch):
+                let inRegional = self.availableChannels.contains { $0.geohash == ch.geohash }
+                if inRegional {
+                    self.teleported = false
+                    if self.teleportedSet.contains(ch.geohash) {
+                        self.teleportedSet.remove(ch.geohash)
+                        self.persistTeleportedSet()
+                    }
+                } else {
+                    self.teleported = self.teleportedSet.contains(ch.geohash)
+                }
+            }
+        }
+    }
+
+    func markTeleported(for geohash: String, _ flag: Bool) {
+        if flag {
+            teleportedSet.insert(geohash)
+        } else {
+            teleportedSet.remove(geohash)
+        }
+        persistTeleportedSet()
+        if case .location(let ch) = selectedChannel, ch.geohash == geohash {
+            Task { @MainActor in self.teleported = flag }
+        }
+    }
+
+    // MARK: - Public API (Bookmarks)
+
+    func isBookmarked(_ geohash: String) -> Bool {
+        bookmarkMembership.contains(Self.normalizeGeohash(geohash))
+    }
+
+    func toggleBookmark(_ geohash: String) {
+        let gh = Self.normalizeGeohash(geohash)
+        if bookmarkMembership.contains(gh) {
+            removeBookmark(gh)
+        } else {
+            addBookmark(gh)
+        }
+    }
+
+    func addBookmark(_ geohash: String) {
+        let gh = Self.normalizeGeohash(geohash)
+        guard !gh.isEmpty, !bookmarkMembership.contains(gh) else { return }
+        bookmarks.insert(gh, at: 0)
+        bookmarkMembership.insert(gh)
+        persistBookmarks()
+        resolveBookmarkNameIfNeeded(for: gh)
+    }
+
+    func removeBookmark(_ geohash: String) {
+        let gh = Self.normalizeGeohash(geohash)
+        guard bookmarkMembership.contains(gh) else { return }
+        if let idx = bookmarks.firstIndex(of: gh) {
+            bookmarks.remove(at: idx)
+        }
+        bookmarkMembership.remove(gh)
+        if bookmarkNames.removeValue(forKey: gh) != nil {
+            persistBookmarkNames()
+        }
+        persistBookmarks()
+    }
+
+    // MARK: - CLLocationManagerDelegate
+
+    private func requestOneShotLocation() {
+        cl.requestLocation()
+    }
+
+    func locationManager(_ manager: CLLocationManager, didChangeAuthorization status: CLAuthorizationStatus) {
+        updatePermissionState(from: status)
+        if case .authorized = permissionState {
+            requestOneShotLocation()
+        }
+    }
+
+    @available(iOS 14.0, macOS 11.0, *)
+    func locationManagerDidChangeAuthorization(_ manager: CLLocationManager) {
+        updatePermissionState(from: manager.authorizationStatus)
+        if case .authorized = permissionState {
+            requestOneShotLocation()
+        }
+    }
+
+    func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
+        guard let loc = locations.last else { return }
+        lastLocation = loc
+        computeChannels(from: loc.coordinate)
+        reverseGeocodeLocation(loc)
+    }
+
+    func locationManager(_ manager: CLLocationManager, didFailWithError error: Error) {
+        SecureLogger.error("LocationStateManager: location error: \(error.localizedDescription)", category: .session)
+    }
+
+    // MARK: - Private Helpers (Permission)
+
+    private func updatePermissionState(from status: CLAuthorizationStatus) {
+        let newState: PermissionState
+        switch status {
+        case .notDetermined: newState = .notDetermined
+        case .restricted: newState = .restricted
+        case .denied: newState = .denied
+        case .authorizedAlways, .authorizedWhenInUse, .authorized: newState = .authorized
+        @unknown default: newState = .restricted
+        }
+        Task { @MainActor in self.permissionState = newState }
+    }
+
+    // MARK: - Private Helpers (Channel Computation)
+
+    private func computeChannels(from coord: CLLocationCoordinate2D) {
+        let levels = GeohashChannelLevel.allCases
+        var result: [GeohashChannel] = []
+        for level in levels {
+            let gh = Geohash.encode(latitude: coord.latitude, longitude: coord.longitude, precision: level.precision)
+            result.append(GeohashChannel(level: level, geohash: gh))
+        }
+        Task { @MainActor in
+            self.availableChannels = result
+            switch self.selectedChannel {
+            case .mesh:
+                self.teleported = false
+            case .location(let ch):
+                let inRegional = result.contains { $0.geohash == ch.geohash }
+                if inRegional {
+                    self.teleported = false
+                    if self.teleportedSet.contains(ch.geohash) {
+                        self.teleportedSet.remove(ch.geohash)
+                        self.persistTeleportedSet()
+                    }
+                } else {
+                    self.teleported = true
+                }
+            }
+        }
+    }
+
+    // MARK: - Private Helpers (Geocoding)
+
+    private func reverseGeocodeLocation(_ location: CLLocation) {
+        geocoder.cancelGeocode()
+        isGeocoding = true
+        geocoder.reverseGeocodeLocation(location) { [weak self] placemarks, _ in
+            guard let self = self else { return }
+            self.isGeocoding = false
+            if let pm = placemarks?.first {
+                let names = self.locationNamesByLevel(from: pm)
+                Task { @MainActor in self.locationNames = names }
+            }
+        }
+    }
+
+    private func locationNamesByLevel(from pm: CLPlacemark) -> [GeohashChannelLevel: String] {
+        var dict: [GeohashChannelLevel: String] = [:]
+        if let country = pm.country, !country.isEmpty {
+            dict[.region] = country
+        }
+        if let admin = pm.administrativeArea, !admin.isEmpty {
+            dict[.province] = admin
+        } else if let subAdmin = pm.subAdministrativeArea, !subAdmin.isEmpty {
+            dict[.province] = subAdmin
+        }
+        if let locality = pm.locality, !locality.isEmpty {
+            dict[.city] = locality
+        } else if let subAdmin = pm.subAdministrativeArea, !subAdmin.isEmpty {
+            dict[.city] = subAdmin
+        } else if let admin = pm.administrativeArea, !admin.isEmpty {
+            dict[.city] = admin
+        }
+        if let subLocality = pm.subLocality, !subLocality.isEmpty {
+            dict[.neighborhood] = subLocality
+        } else if let locality = pm.locality, !locality.isEmpty {
+            dict[.neighborhood] = locality
+        }
+        if let subLocality = pm.subLocality, !subLocality.isEmpty {
+            dict[.block] = subLocality
+        } else if let locality = pm.locality, !locality.isEmpty {
+            dict[.block] = locality
+        }
+        if let name = pm.name, !name.isEmpty {
+            dict[.building] = name
+        } else if let thoroughfare = pm.thoroughfare, !thoroughfare.isEmpty {
+            dict[.building] = thoroughfare
+        }
+        return dict
+    }
+
+    func resolveBookmarkNameIfNeeded(for geohash: String) {
+        let gh = Self.normalizeGeohash(geohash)
+        guard !gh.isEmpty, bookmarkNames[gh] == nil, !resolvingNames.contains(gh) else { return }
+        resolvingNames.insert(gh)
+
+        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),
+                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.resolvingNames.remove(gh) }
+                if let pm = placemarks?.first,
+                   let name = Self.nameForGeohashLength(gh.count, from: pm),
+                   !name.isEmpty {
+                    DispatchQueue.main.async {
+                        self.bookmarkNames[gh] = name
+                        self.persistBookmarkNames()
+                    }
+                }
+            }
+        }
+    }
+
+    private func resolveCompositeAdminName(geohash gh: String, points: [CLLocation]) {
+        var uniqueAdmins: [String] = []
+        var seenAdmins = Set<String>()
+        var idx = 0
+
+        func step() {
+            if idx >= points.count {
+                let finalName: String? = {
+                    if uniqueAdmins.count >= 2 { return uniqueAdmins[0] + " and " + uniqueAdmins[1] }
+                    return uniqueAdmins.first
+                }()
+                if let finalName = finalName, !finalName.isEmpty {
+                    DispatchQueue.main.async {
+                        self.bookmarkNames[gh] = finalName
+                        self.persistBookmarkNames()
+                    }
+                }
+                self.resolvingNames.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, !seenAdmins.contains(admin) {
+                        seenAdmins.insert(admin)
+                        uniqueAdmins.append(admin)
+                    } else if let country = pm.country, !country.isEmpty, !seenAdmins.contains(country) {
+                        seenAdmins.insert(country)
+                        uniqueAdmins.append(country)
+                    }
+                }
+                step()
+            }
+        }
+        step()
+    }
+
+    private static func nameForGeohashLength(_ len: Int, from pm: CLPlacemark) -> String? {
+        switch len {
+        case 0...2:
+            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
+        }
+    }
+
+    // MARK: - Private Helpers (Persistence)
+
+    private func persistTeleportedSet() {
+        if let data = try? JSONEncoder().encode(Array(teleportedSet)) {
+            storage.set(data, forKey: teleportedStoreKey)
+        }
+    }
+
+    private func persistBookmarks() {
+        if let data = try? JSONEncoder().encode(bookmarks) {
+            storage.set(data, forKey: bookmarksKey)
+        }
+    }
+
+    private func persistBookmarkNames() {
+        if let data = try? JSONEncoder().encode(bookmarkNames) {
+            storage.set(data, forKey: bookmarkNamesKey)
+        }
+    }
+
+    private static func normalizeGeohash(_ s: String) -> String {
+        let allowed = Set("0123456789bcdefghjkmnpqrstuvwxyz")
+        return s
+            .trimmed
+            .lowercased()
+            .replacingOccurrences(of: "#", with: "")
+            .filter { allowed.contains($0) }
+    }
+}
+
+// MARK: - Backward Compatibility Typealiases
+
+typealias LocationChannelManager = LocationStateManager
+typealias GeohashBookmarksStore = LocationStateManager
+
+// MARK: - Backward Compatibility Extensions
+
+extension LocationStateManager {
+    /// Backward compatibility: toggle bookmark (was GeohashBookmarksStore.toggle)
+    func toggle(_ geohash: String) {
+        toggleBookmark(geohash)
+    }
+
+    /// Backward compatibility: add bookmark (was GeohashBookmarksStore.add)
+    func add(_ geohash: String) {
+        addBookmark(geohash)
+    }
+
+    /// Backward compatibility: remove bookmark (was GeohashBookmarksStore.remove)
+    func remove(_ geohash: String) {
+        removeBookmark(geohash)
+    }
+}
+#endif
@@ -0,0 +1,130 @@
+import Foundation
+
+/// Tracks observed mesh topology and computes hop-by-hop routes.
+final class MeshTopologyTracker {
+    private typealias RoutingID = Data
+
+    private let queue = DispatchQueue(label: "mesh.topology", attributes: .concurrent)
+    private let hopSize = 8
+    // Directed claims: Key claims to see Value (neighbors)
+    private var claims: [RoutingID: Set<RoutingID>] = [:]
+    // Last time we received an update from a node
+    private var lastSeen: [RoutingID: Date] = [:]
+
+    // Maximum age for topology claims to be considered fresh for routing
+    // Routes computed using stale topology can fail when the network has changed
+    private static let routeFreshnessThreshold: TimeInterval = 60 // 60 seconds
+
+    func reset() {
+        queue.sync(flags: .barrier) {
+            self.claims.removeAll()
+            self.lastSeen.removeAll()
+        }
+    }
+
+    /// Update the topology with a node's self-reported neighbor list
+    func updateNeighbors(for sourceData: Data?, neighbors: [Data]) {
+        guard let source = sanitize(sourceData) else { return }
+        // Sanitize neighbors and exclude self-loops
+        let validNeighbors = Set(neighbors.compactMap { sanitize($0) }).subtracting([source])
+        
+        queue.sync(flags: .barrier) {
+            self.claims[source] = validNeighbors
+            self.lastSeen[source] = Date()
+        }
+    }
+
+    func removePeer(_ data: Data?) {
+        guard let peer = sanitize(data) else { return }
+        queue.sync(flags: .barrier) {
+            self.claims.removeValue(forKey: peer)
+            self.lastSeen.removeValue(forKey: peer)
+        }
+    }
+    
+    /// Prune nodes that haven't updated their topology in `age` seconds
+    func prune(olderThan age: TimeInterval) {
+        let deadline = Date().addingTimeInterval(-age)
+        queue.sync(flags: .barrier) {
+            let stale = self.lastSeen.filter { $0.value < deadline }
+            for (peer, _) in stale {
+                self.claims.removeValue(forKey: peer)
+                self.lastSeen.removeValue(forKey: peer)
+            }
+        }
+    }
+
+    func computeRoute(from start: Data?, to goal: Data?, maxHops: Int = 10) -> [Data]? {
+        guard let source = sanitize(start), let target = sanitize(goal) else { return nil }
+        if source == target { return [] } // Direct connection, no intermediate hops
+
+        return queue.sync {
+            let now = Date()
+            let freshnessDeadline = now.addingTimeInterval(-Self.routeFreshnessThreshold)
+
+            // BFS
+            var visited: Set<RoutingID> = [source]
+            // Queue stores paths: [Start, Hop1, Hop2, ..., Current]
+            var queuePaths: [[RoutingID]] = [[source]]
+
+            while !queuePaths.isEmpty {
+                let path = queuePaths.removeFirst()
+                // Limit path length (path contains source + maxHops + target) -> maxHops intermediate
+                // If maxHops = 10, max edges = 11, max nodes = 12.
+                if path.count > maxHops + 1 { continue }
+
+                guard let last = path.last else { continue }
+
+                // Get neighbors that 'last' claims to see
+                guard let neighbors = claims[last] else { continue }
+
+                // Check if 'last' node's topology info is fresh
+                guard let lastSeenTime = lastSeen[last], lastSeenTime > freshnessDeadline else {
+                    continue // Skip stale nodes
+                }
+
+                for neighbor in neighbors {
+                    if visited.contains(neighbor) { continue }
+
+                    // CONFIRMED EDGE CHECK:
+                    // 'last' claims 'neighbor' (checked above)
+                    // Does 'neighbor' claim 'last'?
+                    guard let neighborClaims = claims[neighbor],
+                          neighborClaims.contains(last) else {
+                        continue
+                    }
+
+                    // Check if 'neighbor' node's topology info is fresh
+                    guard let neighborSeenTime = lastSeen[neighbor], neighborSeenTime > freshnessDeadline else {
+                        continue // Skip edges to stale nodes
+                    }
+
+                    var nextPath = path
+                    nextPath.append(neighbor)
+
+                    if neighbor == target {
+                        // Return only intermediate hops
+                        // Path: [Source, I1, I2, Target] -> [I1, I2]
+                        return Array(nextPath.dropFirst().dropLast())
+                    }
+
+                    visited.insert(neighbor)
+                    queuePaths.append(nextPath)
+                }
+            }
+            return nil
+        }
+    }
+
+    // MARK: - Helpers
+
+    private func sanitize(_ data: Data?) -> Data? {
+        guard var value = data, !value.isEmpty else { return nil }
+        if value.count > hopSize {
+            value = Data(value.prefix(hopSize))
+        } else if value.count < hopSize {
+            value.append(Data(repeating: 0, count: hopSize - value.count))
+        }
+        return value
+    }
+}
@@ -0,0 +1,278 @@
+//
+// MessageDeduplicationService.swift
+// bitchat
+//
+// Handles message deduplication using LRU caches.
+// This is free and unencumbered software released into the public domain.
+//
+
+import Foundation
+
+// MARK: - LRU Deduplication Cache
+
+/// Generic LRU (Least Recently Used) cache for deduplication.
+/// Uses an efficient O(1) lookup with periodic compaction.
+/// Thread-safe via @MainActor - all callers are already on main actor.
+@MainActor
+final class LRUDeduplicationCache<Value> {
+    private var map: [String: Value] = [:]
+    private var order: [String] = []
+    private var head: Int = 0
+    private let capacity: Int
+
+    /// Creates a new LRU cache with the specified capacity.
+    /// - Parameter capacity: Maximum number of entries before eviction
+    init(capacity: Int) {
+        precondition(capacity > 0, "LRU cache capacity must be positive")
+        self.capacity = capacity
+    }
+
+    /// Number of active entries in the cache
+    var count: Int {
+        order.count - head
+    }
+
+    /// Checks if a key exists in the cache
+    func contains(_ key: String) -> Bool {
+        map[key] != nil
+    }
+
+    /// Gets the value for a key, or nil if not present
+    func value(for key: String) -> Value? {
+        map[key]
+    }
+
+    /// Records a key-value pair, updating if exists or inserting if new
+    func record(_ key: String, value: Value) {
+        if map[key] == nil {
+            order.append(key)
+        }
+        map[key] = value
+        trimIfNeeded()
+    }
+
+    /// Removes a specific key from the cache
+    func remove(_ key: String) {
+        map.removeValue(forKey: key)
+        // Note: key remains in order array but will be skipped during eviction
+    }
+
+    /// Clears all entries from the cache
+    func clear() {
+        map.removeAll()
+        order.removeAll()
+        head = 0
+    }
+
+    // MARK: - Private
+
+    private func trimIfNeeded() {
+        let activeCount = order.count - head
+        guard activeCount > capacity else { return }
+
+        let overflow = activeCount - capacity
+        for _ in 0..<overflow {
+            guard let victim = popOldest() else { break }
+            map.removeValue(forKey: victim)
+        }
+    }
+
+    private func popOldest() -> String? {
+        // Skip keys that were already removed from map
+        while head < order.count {
+            let key = order[head]
+            head += 1
+
+            // Periodically compact the backing storage
+            if head >= 32 && head * 2 >= order.count {
+                order.removeFirst(head)
+                head = 0
+            }
+
+            // Only return if key is still in map
+            if map[key] != nil {
+                return key
+            }
+        }
+        return nil
+    }
+}
+
+// MARK: - Content Normalizer
+
+/// Normalizes message content for near-duplicate detection.
+enum ContentNormalizer {
+
+    /// Regex to simplify HTTP URLs by stripping query strings and fragments
+    private static let simplifyHTTPURL: NSRegularExpression = {
+        try! NSRegularExpression(
+            pattern: "https?://[^\\s?#]+(?:[?#][^\\s]*)?",
+            options: [.caseInsensitive]
+        )
+    }()
+
+    /// Normalizes content for deduplication comparison.
+    /// - Parameters:
+    ///   - content: The raw message content
+    ///   - prefixLength: Maximum characters to consider (default from TransportConfig)
+    /// - Returns: A hash-based key for comparison
+    static func normalizedKey(
+        _ content: String,
+        prefixLength: Int = TransportConfig.contentKeyPrefixLength
+    ) -> String {
+        // Lowercase for case-insensitive comparison
+        let lowered = content.lowercased()
+        let ns = lowered as NSString
+        let range = NSRange(location: 0, length: ns.length)
+
+        // Simplify URLs by stripping query/fragment
+        var simplified = ""
+        var last = 0
+        for match in simplifyHTTPURL.matches(in: lowered, options: [], range: range) {
+            if match.range.location > last {
+                simplified += ns.substring(with: NSRange(location: last, length: match.range.location - last))
+            }
+            let url = ns.substring(with: match.range)
+            if let queryIndex = url.firstIndex(where: { $0 == "?" || $0 == "#" }) {
+                simplified += String(url[..<queryIndex])
+            } else {
+                simplified += url
+            }
+            last = match.range.location + match.range.length
+        }
+        if last < ns.length {
+            simplified += ns.substring(with: NSRange(location: last, length: ns.length - last))
+        }
+
+        // Trim and collapse whitespace
+        let trimmed = simplified.trimmed
+        let collapsed = trimmed.replacingOccurrences(of: "\\s+", with: " ", options: .regularExpression)
+
+        // Take prefix and hash
+        let prefix = String(collapsed.prefix(prefixLength))
+        let hash = prefix.djb2()
+        return String(format: "h:%016llx", hash)
+    }
+}
+
+// MARK: - Message Deduplication Service
+
+/// Service that manages message deduplication using LRU caches.
+/// Provides separate caches for content-based dedup and Nostr event ID dedup.
+/// Thread-safe via @MainActor - all callers are already on main actor.
+@MainActor
+final class MessageDeduplicationService {
+
+    /// Cache for content-based near-duplicate detection
+    private let contentCache: LRUDeduplicationCache<Date>
+
+    /// Cache for Nostr event ID deduplication
+    private let nostrEventCache: LRUDeduplicationCache<Bool>
+
+    /// Cache for Nostr ACK deduplication (messageId:ackType:senderPubkey format)
+    private let nostrAckCache: LRUDeduplicationCache<Bool>
+
+    /// Creates a new deduplication service with specified capacities.
+    /// - Parameters:
+    ///   - contentCapacity: Max entries for content cache
+    ///   - nostrEventCapacity: Max entries for Nostr event cache
+    init(
+        contentCapacity: Int = TransportConfig.contentLRUCap,
+        nostrEventCapacity: Int = TransportConfig.uiProcessedNostrEventsCap
+    ) {
+        self.contentCache = LRUDeduplicationCache(capacity: contentCapacity)
+        self.nostrEventCache = LRUDeduplicationCache(capacity: nostrEventCapacity)
+        self.nostrAckCache = LRUDeduplicationCache(capacity: nostrEventCapacity)
+    }
+
+    // MARK: - Content Deduplication
+
+    /// Records content with its timestamp for near-duplicate detection.
+    /// - Parameters:
+    ///   - content: The message content
+    ///   - timestamp: When the content was received
+    func recordContent(_ content: String, timestamp: Date) {
+        let key = ContentNormalizer.normalizedKey(content)
+        contentCache.record(key, value: timestamp)
+    }
+
+    /// Records a pre-normalized content key with its timestamp.
+    /// - Parameters:
+    ///   - key: The normalized content key
+    ///   - timestamp: When the content was received
+    func recordContentKey(_ key: String, timestamp: Date) {
+        contentCache.record(key, value: timestamp)
+    }
+
+    /// Gets the timestamp for previously seen content.
+    /// - Parameter content: The message content
+    /// - Returns: The timestamp when first seen, or nil if not seen
+    func contentTimestamp(for content: String) -> Date? {
+        let key = ContentNormalizer.normalizedKey(content)
+        return contentCache.value(for: key)
+    }
+
+    /// Gets the timestamp for a pre-normalized content key.
+    /// - Parameter key: The normalized content key
+    /// - Returns: The timestamp when first seen, or nil if not seen
+    func contentTimestamp(forKey key: String) -> Date? {
+        contentCache.value(for: key)
+    }
+
+    /// Normalizes content to a deduplication key.
+    /// - Parameter content: The raw content
+    /// - Returns: A normalized hash key
+    func normalizedContentKey(_ content: String) -> String {
+        ContentNormalizer.normalizedKey(content)
+    }
+
+    // MARK: - Nostr Event Deduplication
+
+    /// Checks if a Nostr event has already been processed.
+    /// - Parameter eventId: The event ID
+    /// - Returns: true if already processed
+    func hasProcessedNostrEvent(_ eventId: String) -> Bool {
+        nostrEventCache.contains(eventId)
+    }
+
+    /// Records a Nostr event as processed.
+    /// - Parameter eventId: The event ID
+    func recordNostrEvent(_ eventId: String) {
+        nostrEventCache.record(eventId, value: true)
+    }
+
+    // MARK: - Nostr ACK Deduplication
+
+    /// Checks if a Nostr ACK has already been processed.
+    /// - Parameter ackKey: The ACK key in format "messageId:ackType:senderPubkey"
+    /// - Returns: true if already processed
+    func hasProcessedNostrAck(_ ackKey: String) -> Bool {
+        nostrAckCache.contains(ackKey)
+    }
+
+    /// Records a Nostr ACK as processed.
+    /// - Parameter ackKey: The ACK key in format "messageId:ackType:senderPubkey"
+    func recordNostrAck(_ ackKey: String) {
+        nostrAckCache.record(ackKey, value: true)
+    }
+
+    /// Creates an ACK key from components.
+    static func ackKey(messageId: String, ackType: String, senderPubkey: String) -> String {
+        "\(messageId):\(ackType):\(senderPubkey)"
+    }
+
+    // MARK: - Clear
+
+    /// Clears all caches
+    func clearAll() {
+        contentCache.clear()
+        nostrEventCache.clear()
+        nostrAckCache.clear()
+    }
+
+    /// Clears only the Nostr caches (events and ACKs)
+    func clearNostrCaches() {
+        nostrEventCache.clear()
+        nostrAckCache.clear()
+    }
+}
@@ -0,0 +1,472 @@
+//
+// MessageFormattingEngine.swift
+// bitchat
+//
+// Handles message text formatting, including mentions, hashtags, URLs, and tokens.
+// This is free and unencumbered software released into the public domain.
+//
+
+import BitFoundation
+import Foundation
+import SwiftUI
+
+// MARK: - Formatting Context Protocol
+
+/// Protocol defining the context needed for message formatting.
+/// Implemented by ChatViewModel to provide runtime state.
+@MainActor
+protocol MessageFormattingContext: AnyObject {
+    /// The user's current nickname
+    var nickname: String { get }
+
+    /// Determines if a message was sent by the current user
+    func isSelfMessage(_ message: BitchatMessage) -> Bool
+
+    /// Gets the color for a message's sender
+    func senderColor(for message: BitchatMessage, isDark: Bool) -> Color
+
+    /// Resolves a peer ID to a clickable URL
+    func peerURL(for peerID: PeerID) -> URL?
+}
+
+// MARK: - Formatting Engine
+
+/// Handles rich text formatting for chat messages.
+/// Extracts mentions, hashtags, URLs, Lightning invoices, and Cashu tokens.
+final class MessageFormattingEngine {
+
+    // MARK: - Precompiled Regexes
+
+    /// Precompiled regex patterns for message content parsing
+    enum Patterns {
+        static let hashtag: NSRegularExpression = {
+            try! NSRegularExpression(pattern: "#([a-zA-Z0-9_]+)", options: [])
+        }()
+
+        static let mention: NSRegularExpression = {
+            try! NSRegularExpression(pattern: "@([\\p{L}0-9_]+(?:#[a-fA-F0-9]{4})?)", options: [])
+        }()
+
+        static let cashu: NSRegularExpression = {
+            try! NSRegularExpression(pattern: "\\bcashu[AB][A-Za-z0-9._-]{40,}\\b", options: [])
+        }()
+
+        static let bolt11: NSRegularExpression = {
+            try! NSRegularExpression(pattern: "(?i)\\bln(bc|tb|bcrt)[0-9][a-z0-9]{50,}\\b", options: [])
+        }()
+
+        static let lnurl: NSRegularExpression = {
+            try! NSRegularExpression(pattern: "(?i)\\blnurl1[a-z0-9]{20,}\\b", options: [])
+        }()
+
+        static let lightningScheme: NSRegularExpression = {
+            try! NSRegularExpression(pattern: "(?i)\\blightning:[^\\s]+", options: [])
+        }()
+
+        static let linkDetector: NSDataDetector? = {
+            try? NSDataDetector(types: NSTextCheckingResult.CheckingType.link.rawValue)
+        }()
+
+        static let quickCashuPresence: NSRegularExpression = {
+            try! NSRegularExpression(pattern: "\\bcashu[AB][A-Za-z0-9._-]{40,}\\b", options: [])
+        }()
+
+        static let simplifyHTTPURL: NSRegularExpression = {
+            try! NSRegularExpression(pattern: "https?://[^\\s?#]+(?:[?#][^\\s]*)?", options: [.caseInsensitive])
+        }()
+    }
+
+    // MARK: - Match Types
+
+    /// Types of matches found in message content
+    enum MatchType: String {
+        case hashtag
+        case mention
+        case url
+        case cashu
+        case lightning
+        case bolt11
+        case lnurl
+    }
+
+    /// A match found in message content
+    struct ContentMatch {
+        let range: NSRange
+        let type: MatchType
+    }
+
+    // MARK: - Public API
+
+    /// Formats a message with rich text styling
+    @MainActor
+    static func formatMessage(
+        _ message: BitchatMessage,
+        context: MessageFormattingContext,
+        colorScheme: ColorScheme
+    ) -> AttributedString {
+        let isDark = colorScheme == .dark
+        let isSelf = context.isSelfMessage(message)
+
+        // Check cache first
+        if let cached = message.getCachedFormattedText(isDark: isDark, isSelf: isSelf) {
+            return cached
+        }
+
+        var result = AttributedString()
+        let baseColor: Color = isSelf ? .orange : context.senderColor(for: message, isDark: isDark)
+
+        // Format system messages differently
+        if message.sender == "system" {
+            result = formatSystemMessage(message, isDark: isDark)
+        } else {
+            // Format sender header
+            result = formatSenderHeader(
+                message: message,
+                baseColor: baseColor,
+                isSelf: isSelf,
+                context: context
+            )
+
+            // Format content
+            let contentResult = formatContent(
+                message.content,
+                baseColor: baseColor,
+                isSelf: isSelf,
+                isMentioned: message.mentions?.contains(context.nickname) ?? false
+            )
+            result.append(contentResult)
+
+            // Add timestamp
+            result.append(formatTimestamp(message.formattedTimestamp))
+        }
+
+        // Cache the result
+        message.setCachedFormattedText(result, isDark: isDark, isSelf: isSelf)
+
+        return result
+    }
+
+    /// Formats just the message header (sender portion)
+    @MainActor
+    static func formatHeader(
+        _ message: BitchatMessage,
+        context: MessageFormattingContext,
+        colorScheme: ColorScheme
+    ) -> AttributedString {
+        let isDark = colorScheme == .dark
+        let isSelf = context.isSelfMessage(message)
+        let baseColor: Color = isSelf ? .orange : context.senderColor(for: message, isDark: isDark)
+
+        if message.sender == "system" {
+            var style = AttributeContainer()
+            style.foregroundColor = baseColor
+            style.font = .bitchatSystem(size: 14, weight: .medium, design: .monospaced)
+            return AttributedString(message.sender).mergingAttributes(style)
+        }
+
+        return formatSenderHeader(
+            message: message,
+            baseColor: baseColor,
+            isSelf: isSelf,
+            context: context
+        )
+    }
+
+    /// Extracts mentions from message content
+    static func extractMentions(from content: String) -> [String] {
+        let nsContent = content as NSString
+        let range = NSRange(location: 0, length: nsContent.length)
+        let matches = Patterns.mention.matches(in: content, options: [], range: range)
+
+        return matches.compactMap { match -> String? in
+            guard match.numberOfRanges > 1 else { return nil }
+            let captureRange = match.range(at: 1)
+            guard let swiftRange = Range(captureRange, in: content) else { return nil }
+            return String(content[swiftRange])
+        }
+    }
+
+    /// Checks if content contains a Cashu token
+    static func containsCashuToken(_ content: String) -> Bool {
+        let nsContent = content as NSString
+        let range = NSRange(location: 0, length: nsContent.length)
+        return Patterns.quickCashuPresence.numberOfMatches(in: content, options: [], range: range) > 0
+    }
+
+    // MARK: - Private Helpers
+
+    private static func formatSystemMessage(_ message: BitchatMessage, isDark: Bool) -> AttributedString {
+        var result = AttributedString()
+
+        let content = AttributedString("* \(message.content) *")
+        var contentStyle = AttributeContainer()
+        contentStyle.foregroundColor = Color.gray
+        contentStyle.font = .bitchatSystem(size: 12, design: .monospaced).italic()
+        result.append(content.mergingAttributes(contentStyle))
+
+        // Add timestamp
+        let timestamp = AttributedString(" [\(message.formattedTimestamp)]")
+        var timestampStyle = AttributeContainer()
+        timestampStyle.foregroundColor = Color.gray.opacity(0.5)
+        timestampStyle.font = .bitchatSystem(size: 10, design: .monospaced)
+        result.append(timestamp.mergingAttributes(timestampStyle))
+
+        return result
+    }
+
+    @MainActor
+    private static func formatSenderHeader(
+        message: BitchatMessage,
+        baseColor: Color,
+        isSelf: Bool,
+        context: MessageFormattingContext
+    ) -> AttributedString {
+        var result = AttributedString()
+
+        let (baseName, suffix) = message.sender.splitSuffix()
+        var senderStyle = AttributeContainer()
+        senderStyle.foregroundColor = baseColor
+        let fontWeight: Font.Weight = isSelf ? .bold : .medium
+        senderStyle.font = .bitchatSystem(size: 14, weight: fontWeight, design: .monospaced)
+
+        // Make sender clickable
+        if let spid = message.senderPeerID, let url = context.peerURL(for: spid) {
+            senderStyle.link = url
+        }
+
+        // Build: "<@baseName#suffix> "
+        result.append(AttributedString("<@").mergingAttributes(senderStyle))
+        result.append(AttributedString(baseName).mergingAttributes(senderStyle))
+
+        if !suffix.isEmpty {
+            var suffixStyle = senderStyle
+            suffixStyle.foregroundColor = baseColor.opacity(0.6)
+            result.append(AttributedString(suffix).mergingAttributes(suffixStyle))
+        }
+
+        result.append(AttributedString("> ").mergingAttributes(senderStyle))
+
+        return result
+    }
+
+    private static func formatContent(
+        _ content: String,
+        baseColor: Color,
+        isSelf: Bool,
+        isMentioned: Bool
+    ) -> AttributedString {
+        // For very long content without special tokens, use plain formatting
+        let containsCashu = containsCashuToken(content)
+        if (content.count > 4000 || content.hasVeryLongToken(threshold: 1024)) && !containsCashu {
+            return formatPlainContent(content, baseColor: baseColor, isSelf: isSelf)
+        }
+
+        // Find all matches
+        let matches = findAllMatches(in: content)
+
+        // Build formatted content
+        var result = AttributedString()
+        var lastEnd = content.startIndex
+
+        for match in matches {
+            guard let swiftRange = Range(match.range, in: content) else { continue }
+
+            // Add text before match
+            if lastEnd < swiftRange.lowerBound {
+                let beforeText = String(content[lastEnd..<swiftRange.lowerBound])
+                result.append(formatPlainText(beforeText, baseColor: baseColor, isSelf: isSelf, isMentioned: isMentioned))
+            }
+
+            // Add styled match
+            let matchText = String(content[swiftRange])
+            result.append(formatMatch(matchText, type: match.type, baseColor: baseColor, isSelf: isSelf))
+
+            lastEnd = swiftRange.upperBound
+        }
+
+        // Add remaining text
+        if lastEnd < content.endIndex {
+            let remainingText = String(content[lastEnd...])
+            result.append(formatPlainText(remainingText, baseColor: baseColor, isSelf: isSelf, isMentioned: isMentioned))
+        }
+
+        return result
+    }
+
+    private static func findAllMatches(in content: String) -> [ContentMatch] {
+        let nsContent = content as NSString
+        let nsLen = nsContent.length
+        let fullRange = NSRange(location: 0, length: nsLen)
+
+        // Quick hints to avoid unnecessary regex work
+        let hasMentions = content.contains("@")
+        let hasHashtags = content.contains("#")
+        let hasURLs = content.contains("://") || content.contains("www.") || content.contains("http")
+        let hasLightning = content.lowercased().contains("ln") || content.lowercased().contains("lightning:")
+        let hasCashu = content.lowercased().contains("cashu")
+
+        // Collect matches
+        let mentionMatches = hasMentions ? Patterns.mention.matches(in: content, options: [], range: fullRange) : []
+        let hashtagMatches = hasHashtags ? Patterns.hashtag.matches(in: content, options: [], range: fullRange) : []
+        let urlMatches = hasURLs ? (Patterns.linkDetector?.matches(in: content, options: [], range: fullRange) ?? []) : []
+        let cashuMatches = hasCashu ? Patterns.cashu.matches(in: content, options: [], range: fullRange) : []
+        let lightningMatches = hasLightning ? Patterns.lightningScheme.matches(in: content, options: [], range: fullRange) : []
+        let bolt11Matches = hasLightning ? Patterns.bolt11.matches(in: content, options: [], range: fullRange) : []
+        let lnurlMatches = hasLightning ? Patterns.lnurl.matches(in: content, options: [], range: fullRange) : []
+
+        // Build mention ranges for overlap checking
+        let mentionRanges = mentionMatches.map { $0.range(at: 0) }
+
+        func overlapsMention(_ r: NSRange) -> Bool {
+            mentionRanges.contains { NSIntersectionRange(r, $0).length > 0 }
+        }
+
+        func isStandaloneHashtag(_ r: NSRange) -> Bool {
+            guard let swiftRange = Range(r, in: content) else { return false }
+            if swiftRange.lowerBound == content.startIndex { return true }
+            let prev = content.index(before: swiftRange.lowerBound)
+            return content[prev].isWhitespace || content[prev].isNewline
+        }
+
+        func attachedToMention(_ r: NSRange) -> Bool {
+            guard let swiftRange = Range(r, in: content), swiftRange.lowerBound > content.startIndex else { return false }
+            var i = content.index(before: swiftRange.lowerBound)
+            while true {
+                let ch = content[i]
+                if ch.isWhitespace || ch.isNewline { break }
+                if ch == "@" { return true }
+                if i == content.startIndex { break }
+                i = content.index(before: i)
+            }
+            return false
+        }
+
+        var allMatches: [ContentMatch] = []
+
+        // Add hashtags (excluding those attached to mentions)
+        for match in hashtagMatches {
+            let range = match.range(at: 0)
+            if !overlapsMention(range) && !attachedToMention(range) && isStandaloneHashtag(range) {
+                allMatches.append(ContentMatch(range: range, type: .hashtag))
+            }
+        }
+
+        // Add mentions
+        for match in mentionMatches {
+            allMatches.append(ContentMatch(range: match.range(at: 0), type: .mention))
+        }
+
+        // Add URLs
+        for match in urlMatches where !overlapsMention(match.range) {
+            allMatches.append(ContentMatch(range: match.range, type: .url))
+        }
+
+        // Add Cashu tokens
+        for match in cashuMatches where !overlapsMention(match.range(at: 0)) {
+            allMatches.append(ContentMatch(range: match.range(at: 0), type: .cashu))
+        }
+
+        // Add Lightning scheme URLs
+        for match in lightningMatches where !overlapsMention(match.range(at: 0)) {
+            allMatches.append(ContentMatch(range: match.range(at: 0), type: .lightning))
+        }
+
+        // Add bolt11/lnurl (avoiding overlaps with lightning scheme and URLs)
+        let occupied = urlMatches.map { $0.range } + lightningMatches.map { $0.range(at: 0) }
+        func overlapsOccupied(_ r: NSRange) -> Bool {
+            occupied.contains { NSIntersectionRange(r, $0).length > 0 }
+        }
+
+        for match in bolt11Matches where !overlapsMention(match.range(at: 0)) && !overlapsOccupied(match.range(at: 0)) {
+            allMatches.append(ContentMatch(range: match.range(at: 0), type: .bolt11))
+        }
+
+        for match in lnurlMatches where !overlapsMention(match.range(at: 0)) && !overlapsOccupied(match.range(at: 0)) {
+            allMatches.append(ContentMatch(range: match.range(at: 0), type: .lnurl))
+        }
+
+        // Sort by position
+        return allMatches.sorted { $0.range.location < $1.range.location }
+    }
+
+    private static func formatPlainContent(_ content: String, baseColor: Color, isSelf: Bool) -> AttributedString {
+        var style = AttributeContainer()
+        style.foregroundColor = baseColor
+        style.font = isSelf
+            ? .bitchatSystem(size: 14, weight: .bold, design: .monospaced)
+            : .bitchatSystem(size: 14, design: .monospaced)
+        return AttributedString(content).mergingAttributes(style)
+    }
+
+    private static func formatPlainText(_ text: String, baseColor: Color, isSelf: Bool, isMentioned: Bool) -> AttributedString {
+        guard !text.isEmpty else { return AttributedString() }
+
+        var style = AttributeContainer()
+        style.foregroundColor = baseColor
+        style.font = isSelf
+            ? .bitchatSystem(size: 14, weight: .bold, design: .monospaced)
+            : .bitchatSystem(size: 14, design: .monospaced)
+
+        if isMentioned {
+            style.font = style.font?.bold()
+        }
+
+        return AttributedString(text).mergingAttributes(style)
+    }
+
+    private static func formatMatch(_ text: String, type: MatchType, baseColor: Color, isSelf: Bool) -> AttributedString {
+        var style = AttributeContainer()
+
+        switch type {
+        case .mention:
+            // Split optional '#abcd' suffix
+            let (baseName, suffix) = text.splitSuffix()
+            var result = AttributedString()
+
+            var mentionStyle = AttributeContainer()
+            mentionStyle.foregroundColor = .blue
+            mentionStyle.font = .bitchatSystem(size: 14, weight: .semibold, design: .monospaced)
+            result.append(AttributedString(baseName).mergingAttributes(mentionStyle))
+
+            if !suffix.isEmpty {
+                var suffixStyle = mentionStyle
+                suffixStyle.foregroundColor = Color.gray.opacity(0.7)
+                result.append(AttributedString(suffix).mergingAttributes(suffixStyle))
+            }
+
+            return result
+
+        case .hashtag:
+            style.foregroundColor = .purple
+            style.font = .bitchatSystem(size: 14, weight: .medium, design: .monospaced)
+
+        case .url:
+            style.foregroundColor = .blue
+            style.font = .bitchatSystem(size: 14, design: .monospaced)
+            style.underlineStyle = .single
+            if let url = URL(string: text) {
+                style.link = url
+            }
+
+        case .cashu:
+            style.foregroundColor = .green
+            style.font = .bitchatSystem(size: 14, weight: .medium, design: .monospaced)
+            style.backgroundColor = Color.green.opacity(0.1)
+
+        case .lightning, .bolt11, .lnurl:
+            style.foregroundColor = .yellow
+            style.font = .bitchatSystem(size: 14, weight: .medium, design: .monospaced)
+            style.backgroundColor = Color.yellow.opacity(0.1)
+        }
+
+        return AttributedString(text).mergingAttributes(style)
+    }
+
+    private static func formatTimestamp(_ timestamp: String) -> AttributedString {
+        let text = AttributedString(" [\(timestamp)]")
+        var style = AttributeContainer()
+        style.foregroundColor = Color.gray.opacity(0.5)
+        style.font = .bitchatSystem(size: 10, design: .monospaced)
+        return text.mergingAttributes(style)
+    }
+}
@@ -1,17 +1,28 @@
 import BitLogger
+import BitFoundation
 import Foundation

-/// Routes messages between BLE and Nostr transports
+/// Routes messages using available transports (Mesh, Nostr, etc.)
@MainActor
 final class MessageRouter {
-    private let mesh: Transport
-    private let nostr: NostrTransport
-    private var outbox: [PeerID: [(content: String, nickname: String, messageID: String)]] = [:] // peerID -> queued messages
+    private let transports: [Transport]

-    init(mesh: Transport, nostr: NostrTransport) {
-        self.mesh = mesh
-        self.nostr = nostr
-        self.nostr.senderPeerID = mesh.myPeerID
+    // Outbox entry with timestamp for TTL-based eviction
+    private struct QueuedMessage {
+        let content: String
+        let nickname: String
+        let messageID: String
+        let timestamp: Date
+    }
+
+    private var outbox: [PeerID: [QueuedMessage]] = [:]
+
+    // Outbox limits to prevent unbounded memory growth
+    private static let maxMessagesPerPeer = 100
+    private static let messageTTLSeconds: TimeInterval = 24 * 60 * 60 // 24 hours
+
+    init(transports: [Transport]) {
+        self.transports = transports

        // Observe favorites changes to learn Nostr mapping and flush queued messages
        NotificationCenter.default.addObserver(
@@ -37,89 +48,87 @@ final class MessageRouter {
        }
    }

+    // MARK: - Transport Selection
+
+    private func reachableTransport(for peerID: PeerID) -> Transport? {
+        transports.first { $0.isPeerReachable(peerID) }
+    }
+
+    private func connectedTransport(for peerID: PeerID) -> Transport? {
+        transports.first { $0.isPeerConnected(peerID) }
+    }
+
+    // MARK: - Message Sending
+
    func sendPrivate(_ content: String, to peerID: PeerID, recipientNickname: String, messageID: String) {
-        let reachableMesh = mesh.isPeerReachable(peerID)
-        if reachableMesh {
-            SecureLogger.debug("Routing PM via mesh (reachable) to \(peerID.id.prefix(8))… id=\(messageID.prefix(8))…", category: .session)
-            // BLEService will initiate a handshake if needed and queue the message
-            mesh.sendPrivateMessage(content, to: peerID, recipientNickname: recipientNickname, messageID: messageID)
-        } else if canSendViaNostr(peerID: peerID) {
-            SecureLogger.debug("Routing PM via Nostr to \(peerID.id.prefix(8))… id=\(messageID.prefix(8))…", category: .session)
-            nostr.sendPrivateMessage(content, to: peerID, recipientNickname: recipientNickname, messageID: messageID)
+        if let transport = reachableTransport(for: peerID) {
+            SecureLogger.debug("Routing PM via \(type(of: transport)) to \(peerID.id.prefix(8))… id=\(messageID.prefix(8))…", category: .session)
+            transport.sendPrivateMessage(content, to: peerID, recipientNickname: recipientNickname, messageID: messageID)
        } else {
-            // Queue for later (when mesh connects or Nostr mapping appears)
+            // Queue for later with timestamp for TTL tracking
            if outbox[peerID] == nil { outbox[peerID] = [] }
-            outbox[peerID]?.append((content, recipientNickname, messageID))
-            SecureLogger.debug("Queued PM for \(peerID.id.prefix(8))… (no mesh, no Nostr mapping) id=\(messageID.prefix(8))…", category: .session)
+
+            let message = QueuedMessage(content: content, nickname: recipientNickname, messageID: messageID, timestamp: Date())
+            outbox[peerID]?.append(message)
+
+            // Enforce per-peer size limit with FIFO eviction
+            if let count = outbox[peerID]?.count, count > Self.maxMessagesPerPeer {
+                let evicted = outbox[peerID]?.removeFirst()
+                SecureLogger.warning("📤 Outbox overflow for \(peerID.id.prefix(8))… - evicted oldest message: \(evicted?.messageID.prefix(8) ?? "?")…", category: .session)
+            }
+
+            SecureLogger.debug("Queued PM for \(peerID.id.prefix(8))… (no reachable transport) id=\(messageID.prefix(8))… queue=\(outbox[peerID]?.count ?? 0)", category: .session)
        }
    }

    func sendReadReceipt(_ receipt: ReadReceipt, to peerID: PeerID) {
-        // Prefer mesh for reachable peers; BLE will queue if handshake is needed
-        if mesh.isPeerReachable(peerID) {
-            SecureLogger.debug("Routing READ ack via mesh (reachable) to \(peerID.id.prefix(8))… id=\(receipt.originalMessageID.prefix(8))…", category: .session)
-            mesh.sendReadReceipt(receipt, to: peerID)
-        } else {
-            SecureLogger.debug("Routing READ ack via Nostr to \(peerID.id.prefix(8))… id=\(receipt.originalMessageID.prefix(8))…", category: .session)
-            nostr.sendReadReceipt(receipt, to: peerID)
+        if let transport = reachableTransport(for: peerID) {
+            SecureLogger.debug("Routing READ ack via \(type(of: transport)) to \(peerID.id.prefix(8))… id=\(receipt.originalMessageID.prefix(8))…", category: .session)
+            transport.sendReadReceipt(receipt, to: peerID)
+        } else if !transports.isEmpty {
+            SecureLogger.debug("No reachable transport for READ ack to \(peerID.id.prefix(8))…", category: .session)
        }
    }

    func sendDeliveryAck(_ messageID: String, to peerID: PeerID) {
-        if mesh.isPeerReachable(peerID) {
-            SecureLogger.debug("Routing DELIVERED ack via mesh (reachable) to \(peerID.id.prefix(8))… id=\(messageID.prefix(8))…", category: .session)
-            mesh.sendDeliveryAck(for: messageID, to: peerID)
-        } else {
-            nostr.sendDeliveryAck(for: messageID, to: peerID)
+        if let transport = reachableTransport(for: peerID) {
+            SecureLogger.debug("Routing DELIVERED ack via \(type(of: transport)) to \(peerID.id.prefix(8))… id=\(messageID.prefix(8))…", category: .session)
+            transport.sendDeliveryAck(for: messageID, to: peerID)
        }
    }

    func sendFavoriteNotification(to peerID: PeerID, isFavorite: Bool) {
-        // Route via mesh when connected; else use Nostr
-        if mesh.isPeerConnected(peerID) {
-            mesh.sendFavoriteNotification(to: peerID, isFavorite: isFavorite)
-        } else {
-            nostr.sendFavoriteNotification(to: peerID, isFavorite: isFavorite)
+        if let transport = connectedTransport(for: peerID) {
+            transport.sendFavoriteNotification(to: peerID, isFavorite: isFavorite)
+        } else if let transport = reachableTransport(for: peerID) {
+            transport.sendFavoriteNotification(to: peerID, isFavorite: isFavorite)
        }
    }

    // MARK: - Outbox Management
-    private func canSendViaNostr(peerID: PeerID) -> Bool {
-        // Two forms are supported:
-        // - 64-hex Noise public key (32 bytes)
-        // - 16-hex short peer ID (derived from Noise pubkey)
-        if let noiseKey = peerID.noiseKey {
-            if let fav = FavoritesPersistenceService.shared.getFavoriteStatus(for: noiseKey),
-               fav.peerNostrPublicKey != nil {
-                return true
-            }
-        } else if peerID.isShort {
-            if let fav = FavoritesPersistenceService.shared.getFavoriteStatus(forPeerID: peerID),
-               fav.peerNostrPublicKey != nil {
-                return true
-            }
-        }
-        return false
-    }

    func flushOutbox(for peerID: PeerID) {
        guard let queued = outbox[peerID], !queued.isEmpty else { return }
        SecureLogger.debug("Flushing outbox for \(peerID.id.prefix(8))… count=\(queued.count)", category: .session)
-        var remaining: [(content: String, nickname: String, messageID: String)] = []
-        // Prefer mesh if connected; else try Nostr if mapping exists
-        for (content, nickname, messageID) in queued {
-            if mesh.isPeerReachable(peerID) {
-                SecureLogger.debug("Outbox -> mesh for \(peerID.id.prefix(8))… id=\(messageID.prefix(8))…", category: .session)
-                mesh.sendPrivateMessage(content, to: peerID, recipientNickname: nickname, messageID: messageID)
-            } else if canSendViaNostr(peerID: peerID) {
-                SecureLogger.debug("Outbox -> Nostr for \(peerID.id.prefix(8))… id=\(messageID.prefix(8))…", category: .session)
-                nostr.sendPrivateMessage(content, to: peerID, recipientNickname: nickname, messageID: messageID)
+
+        let now = Date()
+        var remaining: [QueuedMessage] = []
+
+        for message in queued {
+            // Skip expired messages (TTL exceeded)
+            if now.timeIntervalSince(message.timestamp) > Self.messageTTLSeconds {
+                SecureLogger.debug("⏰ Expired queued message for \(peerID.id.prefix(8))… id=\(message.messageID.prefix(8))… (age: \(Int(now.timeIntervalSince(message.timestamp)))s)", category: .session)
+                continue
+            }
+
+            if let transport = reachableTransport(for: peerID) {
+                SecureLogger.debug("Outbox -> \(type(of: transport)) for \(peerID.id.prefix(8))… id=\(message.messageID.prefix(8))…", category: .session)
+                transport.sendPrivateMessage(message.content, to: peerID, recipientNickname: message.nickname, messageID: message.messageID)
            } else {
-                // Keep unsent items queued
-                remaining.append((content, nickname, messageID))
+                remaining.append(message)
            }
        }
-        // Persist only items we could not send
+
        if remaining.isEmpty {
            outbox.removeValue(forKey: peerID)
        } else {
@@ -130,4 +139,15 @@ final class MessageRouter {
    func flushAllOutbox() {
        for key in Array(outbox.keys) { flushOutbox(for: key) }
    }
+
+    /// Periodically clean up expired messages from all outboxes
+    func cleanupExpiredMessages() {
+        let now = Date()
+        for peerID in Array(outbox.keys) {
+            outbox[peerID]?.removeAll { now.timeIntervalSince($0.timestamp) > Self.messageTTLSeconds }
+            if outbox[peerID]?.isEmpty == true {
+                outbox.removeValue(forKey: peerID)
+            }
+        }
+    }
 }
@@ -3,6 +3,27 @@ import BitLogger
 import Combine
 import Tor

+@MainActor
+protocol NetworkActivationTorControlling: AnyObject {
+    func setAutoStartAllowed(_ allowed: Bool)
+    func startIfNeeded()
+    func shutdownCompletely()
+}
+
+@MainActor
+protocol NetworkActivationRelayControlling: AnyObject {
+    func connect()
+    func disconnect()
+}
+
+protocol NetworkActivationProxyControlling: AnyObject {
+    func setProxyMode(useTor: Bool)
+}
+
+extension TorManager: NetworkActivationTorControlling {}
+extension NostrRelayManager: NetworkActivationRelayControlling {}
+extension TorURLSession: NetworkActivationProxyControlling {}
+
 /// Coordinates when the app is allowed to start Tor and connect to Nostr relays.
 /// Policy: permit start when either location permissions are authorized OR
 /// there exists at least one mutual favorite. Otherwise, do not start.
@@ -17,14 +38,55 @@ final class NetworkActivationService: ObservableObject {
    private var started = false
    private let torPreferenceKey = "networkActivationService.userTorEnabled"
    private var torAutoStartDesired: Bool = false
+    private let storage: UserDefaults
+    private let locationPermissionPublisher: AnyPublisher<LocationChannelManager.PermissionState, Never>
+    private let mutualFavoritesPublisher: AnyPublisher<Set<Data>, Never>
+    private let permissionProvider: () -> LocationChannelManager.PermissionState
+    private let mutualFavoritesProvider: () -> Set<Data>
+    private let torController: NetworkActivationTorControlling
+    private let relayController: NetworkActivationRelayControlling
+    private let proxyController: NetworkActivationProxyControlling
+    private let notificationCenter: NotificationCenter

-    private init() {}
+    private init() {
+        storage = .standard
+        locationPermissionPublisher = LocationChannelManager.shared.$permissionState.eraseToAnyPublisher()
+        mutualFavoritesPublisher = FavoritesPersistenceService.shared.$mutualFavorites.eraseToAnyPublisher()
+        permissionProvider = { LocationChannelManager.shared.permissionState }
+        mutualFavoritesProvider = { FavoritesPersistenceService.shared.mutualFavorites }
+        torController = TorManager.shared
+        relayController = NostrRelayManager.shared
+        proxyController = TorURLSession.shared
+        notificationCenter = .default
+    }
+
+    internal init(
+        storage: UserDefaults,
+        locationPermissionPublisher: AnyPublisher<LocationChannelManager.PermissionState, Never>,
+        mutualFavoritesPublisher: AnyPublisher<Set<Data>, Never>,
+        permissionProvider: @escaping () -> LocationChannelManager.PermissionState,
+        mutualFavoritesProvider: @escaping () -> Set<Data>,
+        torController: NetworkActivationTorControlling,
+        relayController: NetworkActivationRelayControlling,
+        proxyController: NetworkActivationProxyControlling,
+        notificationCenter: NotificationCenter = .default
+    ) {
+        self.storage = storage
+        self.locationPermissionPublisher = locationPermissionPublisher
+        self.mutualFavoritesPublisher = mutualFavoritesPublisher
+        self.permissionProvider = permissionProvider
+        self.mutualFavoritesProvider = mutualFavoritesProvider
+        self.torController = torController
+        self.relayController = relayController
+        self.proxyController = proxyController
+        self.notificationCenter = notificationCenter
+    }

    func start() {
        guard !started else { return }
        started = true

-        if let stored = UserDefaults.standard.object(forKey: torPreferenceKey) as? Bool {
+        if let stored = storage.object(forKey: torPreferenceKey) as? Bool {
            userTorEnabled = stored
        } else {
            userTorEnabled = true
@@ -34,16 +96,16 @@ final class NetworkActivationService: ObservableObject {
        let allowed = basePolicyAllowed()
        activationAllowed = allowed
        torAutoStartDesired = allowed && userTorEnabled
-        TorManager.shared.setAutoStartAllowed(torAutoStartDesired)
+        torController.setAutoStartAllowed(torAutoStartDesired)
        applyTorState(torDesired: torAutoStartDesired)
        if allowed {
-            NostrRelayManager.shared.connect()
+            relayController.connect()
        } else {
-            NostrRelayManager.shared.disconnect()
+            relayController.disconnect()
        }

        // React to location permission changes
-        LocationChannelManager.shared.$permissionState
+        locationPermissionPublisher
            .receive(on: DispatchQueue.main)
            .sink { [weak self] _ in
                self?.reevaluate()
@@ -51,7 +113,7 @@ final class NetworkActivationService: ObservableObject {
            .store(in: &cancellables)

        // React to mutual favorites changes
-        FavoritesPersistenceService.shared.$mutualFavorites
+        mutualFavoritesPublisher
            .receive(on: DispatchQueue.main)
            .sink { [weak self] _ in
                self?.reevaluate()
@@ -62,8 +124,8 @@ final class NetworkActivationService: ObservableObject {
    func setUserTorEnabled(_ enabled: Bool) {
        guard enabled != userTorEnabled else { return }
        userTorEnabled = enabled
-        UserDefaults.standard.set(enabled, forKey: torPreferenceKey)
-        NotificationCenter.default.post(
+        storage.set(enabled, forKey: torPreferenceKey)
+        notificationCenter.post(
            name: .TorUserPreferenceChanged,
            object: nil,
            userInfo: ["enabled": enabled]
@@ -82,33 +144,33 @@ final class NetworkActivationService: ObservableObject {
        }
        if statusChanged || torChanged {
            torAutoStartDesired = torDesired
-            TorManager.shared.setAutoStartAllowed(torDesired)
+            torController.setAutoStartAllowed(torDesired)
            applyTorState(torDesired: torDesired)
        }

        if allowed {
            if torChanged {
                // Reset relay sockets when switching transport path (Tor ↔︎ direct)
-                NostrRelayManager.shared.disconnect()
+                relayController.disconnect()
            }
-            NostrRelayManager.shared.connect()
+            relayController.connect()
        } else if statusChanged {
-            NostrRelayManager.shared.disconnect()
+            relayController.disconnect()
        }
    }

    private func basePolicyAllowed() -> Bool {
-        let permOK = LocationChannelManager.shared.permissionState == .authorized
-        let hasMutual = !FavoritesPersistenceService.shared.mutualFavorites.isEmpty
+        let permOK = permissionProvider() == .authorized
+        let hasMutual = !mutualFavoritesProvider().isEmpty
        return permOK || hasMutual
    }

    private func applyTorState(torDesired: Bool) {
-        TorURLSession.shared.setProxyMode(useTor: torDesired)
+        proxyController.setProxyMode(useTor: torDesired)
        if torDesired {
-            TorManager.shared.startIfNeeded()
+            torController.startIfNeeded()
        } else {
-            TorManager.shared.shutdownCompletely()
+            torController.shutdownCompletely()
        }
    }
 }
@@ -83,6 +83,7 @@
 ///

 import BitLogger
+import BitFoundation
 import Foundation
 import CryptoKit

@@ -177,18 +178,18 @@ final class NoiseEncryptionService {
    private let rekeyCheckInterval: TimeInterval = 60.0 // Check every minute
    
    // Callbacks
-    private var onPeerAuthenticatedHandlers: [((String, String) -> Void)] = [] // Array of handlers for peer authentication
+    private var onPeerAuthenticatedHandlers: [((PeerID, String) -> Void)] = [] // Array of handlers for peer authentication
    var onHandshakeRequired: ((PeerID) -> Void)? // peerID needs handshake
    
    // Add a handler for peer authentication
-    func addOnPeerAuthenticatedHandler(_ handler: @escaping (String, String) -> Void) {
+    func addOnPeerAuthenticatedHandler(_ handler: @escaping (PeerID, String) -> Void) {
        serviceQueue.async(flags: .barrier) { [weak self] in
            self?.onPeerAuthenticatedHandlers.append(handler)
        }
    }
    
    // Legacy support - setting this will add to the handlers array
-    var onPeerAuthenticated: ((String, String) -> Void)? {
+    var onPeerAuthenticated: ((PeerID, String) -> Void)? {
        get { nil } // Always return nil for backward compatibility
        set {
            if let handler = newValue {
@@ -199,64 +200,153 @@ final class NoiseEncryptionService {
    
    init(keychain: KeychainManagerProtocol) {
        self.keychain = keychain
-        
-        // Load or create static identity key (ONLY from keychain)
+
+        // BCH-01-009: Load or create static identity key with proper error handling
        let loadedKey: Curve25519.KeyAgreement.PrivateKey
-        
-        // Try to load from keychain
-        if let identityData = keychain.getIdentityKey(forKey: "noiseStaticKey"),
-           let key = try? Curve25519.KeyAgreement.PrivateKey(rawRepresentation: identityData) {
-            loadedKey = key
-            SecureLogger.logKeyOperation(.load, keyType: "noiseStaticKey", success: true)
-        }
-        // If no identity exists, create new one
-        else {
+
+        // Try to load from keychain with proper error classification
+        let noiseKeyResult = keychain.getIdentityKeyWithResult(forKey: "noiseStaticKey")
+
+        switch noiseKeyResult {
+        case .success(let identityData):
+            if let key = try? Curve25519.KeyAgreement.PrivateKey(rawRepresentation: identityData) {
+                loadedKey = key
+                SecureLogger.logKeyOperation(.load, keyType: "noiseStaticKey", success: true)
+            } else {
+                // Data corrupted, regenerate
+                SecureLogger.warning("Noise static key data corrupted, regenerating", category: .keychain)
+                loadedKey = Self.generateAndSaveNoiseKey(keychain: keychain)
+            }
+
+        case .itemNotFound:
+            // Expected case: no key exists yet, create new one
+            loadedKey = Self.generateAndSaveNoiseKey(keychain: keychain)
+
+        case .accessDenied:
+            // Critical error - log but proceed with ephemeral key (will be lost on restart)
+            SecureLogger.error(NSError(domain: "Keychain", code: -1),
+                               context: "Keychain access denied - using ephemeral identity", category: .keychain)
+            loadedKey = Curve25519.KeyAgreement.PrivateKey()
+
+        case .deviceLocked, .authenticationFailed:
+            // Recoverable error - use ephemeral key and warn
+            SecureLogger.warning("Device locked or auth failed - using ephemeral identity until unlocked", category: .keychain)
+            loadedKey = Curve25519.KeyAgreement.PrivateKey()
+
+        case .otherError(let status):
+            // Unexpected error - log and use ephemeral key
+            SecureLogger.error(NSError(domain: "Keychain", code: Int(status)),
+                               context: "Unexpected keychain error - using ephemeral identity", category: .keychain)
            loadedKey = Curve25519.KeyAgreement.PrivateKey()
-            let keyData = loadedKey.rawRepresentation
-            
-            // Save to keychain
-            let saved = keychain.saveIdentityKey(keyData, forKey: "noiseStaticKey")
-            SecureLogger.logKeyOperation(.create, keyType: "noiseStaticKey", success: saved)
        }
-        
+
        // Now assign the final value
        self.staticIdentityKey = loadedKey
        self.staticIdentityPublicKey = staticIdentityKey.publicKey
-        
-        // Load or create signing key pair
+
+        // BCH-01-009: Load or create signing key pair with proper error handling
        let loadedSigningKey: Curve25519.Signing.PrivateKey
-        
-        // Try to load from keychain
-        if let signingData = keychain.getIdentityKey(forKey: "ed25519SigningKey"),
-           let key = try? Curve25519.Signing.PrivateKey(rawRepresentation: signingData) {
-            loadedSigningKey = key
-            SecureLogger.logKeyOperation(.load, keyType: "ed25519SigningKey", success: true)
-        }
-        // If no signing key exists, create new one
-        else {
+
+        let signingKeyResult = keychain.getIdentityKeyWithResult(forKey: "ed25519SigningKey")
+
+        switch signingKeyResult {
+        case .success(let signingData):
+            if let key = try? Curve25519.Signing.PrivateKey(rawRepresentation: signingData) {
+                loadedSigningKey = key
+                SecureLogger.logKeyOperation(.load, keyType: "ed25519SigningKey", success: true)
+            } else {
+                // Data corrupted, regenerate
+                SecureLogger.warning("Ed25519 signing key data corrupted, regenerating", category: .keychain)
+                loadedSigningKey = Self.generateAndSaveSigningKey(keychain: keychain)
+            }
+
+        case .itemNotFound:
+            // Expected case: no key exists yet, create new one
+            loadedSigningKey = Self.generateAndSaveSigningKey(keychain: keychain)
+
+        case .accessDenied:
+            // Critical error - log but proceed with ephemeral key
+            SecureLogger.error(NSError(domain: "Keychain", code: -1),
+                               context: "Keychain access denied - using ephemeral signing key", category: .keychain)
+            loadedSigningKey = Curve25519.Signing.PrivateKey()
+
+        case .deviceLocked, .authenticationFailed:
+            // Recoverable error - use ephemeral key and warn
+            SecureLogger.warning("Device locked or auth failed - using ephemeral signing key until unlocked", category: .keychain)
+            loadedSigningKey = Curve25519.Signing.PrivateKey()
+
+        case .otherError(let status):
+            // Unexpected error - log and use ephemeral key
+            SecureLogger.error(NSError(domain: "Keychain", code: Int(status)),
+                               context: "Unexpected keychain error - using ephemeral signing key", category: .keychain)
            loadedSigningKey = Curve25519.Signing.PrivateKey()
-            let keyData = loadedSigningKey.rawRepresentation
-            
-            // Save to keychain
-            let saved = keychain.saveIdentityKey(keyData, forKey: "ed25519SigningKey")
-            SecureLogger.logKeyOperation(.create, keyType: "ed25519SigningKey", success: saved)
        }
-        
+
        // Now assign the signing keys
        self.signingKey = loadedSigningKey
        self.signingPublicKey = signingKey.publicKey
-        
+
        // Initialize session manager
        self.sessionManager = NoiseSessionManager(localStaticKey: staticIdentityKey, keychain: keychain)
-        
+
        // Set up session callbacks
        sessionManager.onSessionEstablished = { [weak self] peerID, remoteStaticKey in
            self?.handleSessionEstablished(peerID: peerID, remoteStaticKey: remoteStaticKey)
        }
-        
+
        // Start session maintenance timer
        startRekeyTimer()
    }
+
+    // MARK: - BCH-01-009: Key Generation Helpers with Save Verification
+
+    /// Generate and save a new Noise static key, verifying the save succeeds
+    private static func generateAndSaveNoiseKey(keychain: KeychainManagerProtocol) -> Curve25519.KeyAgreement.PrivateKey {
+        let newKey = Curve25519.KeyAgreement.PrivateKey()
+        let keyData = newKey.rawRepresentation
+
+        // Save to keychain and verify success
+        let saveResult = keychain.saveIdentityKeyWithResult(keyData, forKey: "noiseStaticKey")
+
+        switch saveResult {
+        case .success:
+            SecureLogger.logKeyOperation(.create, keyType: "noiseStaticKey", success: true)
+        case .duplicateItem:
+            // This shouldn't happen since we just tried to load, but handle it
+            SecureLogger.warning("Noise key already exists (race condition?)", category: .keychain)
+        default:
+            // Save failed - log but continue with the key (it will be ephemeral)
+            SecureLogger.error(NSError(domain: "Keychain", code: -1),
+                               context: "Failed to persist noise static key - identity will be lost on restart",
+                               category: .keychain)
+        }
+
+        return newKey
+    }
+
+    /// Generate and save a new Ed25519 signing key, verifying the save succeeds
+    private static func generateAndSaveSigningKey(keychain: KeychainManagerProtocol) -> Curve25519.Signing.PrivateKey {
+        let newKey = Curve25519.Signing.PrivateKey()
+        let keyData = newKey.rawRepresentation
+
+        // Save to keychain and verify success
+        let saveResult = keychain.saveIdentityKeyWithResult(keyData, forKey: "ed25519SigningKey")
+
+        switch saveResult {
+        case .success:
+            SecureLogger.logKeyOperation(.create, keyType: "ed25519SigningKey", success: true)
+        case .duplicateItem:
+            // This shouldn't happen since we just tried to load, but handle it
+            SecureLogger.warning("Signing key already exists (race condition?)", category: .keychain)
+        default:
+            // Save failed - log but continue with the key (it will be ephemeral)
+            SecureLogger.error(NSError(domain: "Keychain", code: -1),
+                               context: "Failed to persist signing key - identity will be lost on restart",
+                               category: .keychain)
+        }
+
+        return newKey
+    }
    
    // MARK: - Public Interface
    
@@ -527,6 +617,17 @@ final class NoiseEncryptionService {
        }
        rateLimiter.resetAll()
    }
+
+    /// Clear session for a specific peer (e.g., on decryption failure to allow re-handshake)
+    func clearSession(for peerID: PeerID) {
+        sessionManager.removeSession(for: peerID)
+        serviceQueue.sync(flags: .barrier) {
+            if let fingerprint = peerFingerprints.removeValue(forKey: peerID) {
+                fingerprintToPeerID.removeValue(forKey: fingerprint)
+            }
+        }
+        SecureLogger.debug("🔓 Cleared Noise session for \(peerID)", category: .session)
+    }
    
    // MARK: - Private Helpers
    
@@ -546,7 +647,7 @@ final class NoiseEncryptionService {
        // Notify all handlers about authentication
        serviceQueue.async { [weak self] in
            self?.onPeerAuthenticatedHandlers.forEach { handler in
-                handler(peerID.id, fingerprint)
+                handler(peerID, fingerprint)
            }
        }
    }
@@ -1,9 +1,36 @@
 import BitLogger
+import BitFoundation
 import Foundation
 import Combine

 // Minimal Nostr transport conforming to Transport for offline sending
-final class NostrTransport: Transport {
+final class NostrTransport: Transport, @unchecked Sendable {
+    struct Dependencies {
+        let notificationCenter: NotificationCenter
+        let loadFavorites: @MainActor () -> [Data: FavoritesPersistenceService.FavoriteRelationship]
+        let favoriteStatusForNoiseKey: @MainActor (Data) -> FavoritesPersistenceService.FavoriteRelationship?
+        let favoriteStatusForPeerID: @MainActor (PeerID) -> FavoritesPersistenceService.FavoriteRelationship?
+        let currentIdentity: @MainActor () throws -> NostrIdentity?
+        let registerPendingGiftWrap: @MainActor (String) -> Void
+        let sendEvent: @MainActor (NostrEvent) -> Void
+        let scheduleAfter: @Sendable (TimeInterval, @escaping @Sendable () -> Void) -> Void
+
+        static func live(idBridge: NostrIdentityBridge) -> Dependencies {
+            Dependencies(
+                notificationCenter: .default,
+                loadFavorites: { FavoritesPersistenceService.shared.favorites },
+                favoriteStatusForNoiseKey: { FavoritesPersistenceService.shared.getFavoriteStatus(for: $0) },
+                favoriteStatusForPeerID: { FavoritesPersistenceService.shared.getFavoriteStatus(forPeerID: $0) },
+                currentIdentity: { try idBridge.getCurrentNostrIdentity() },
+                registerPendingGiftWrap: { NostrRelayManager.registerPendingGiftWrap(id: $0) },
+                sendEvent: { NostrRelayManager.shared.sendEvent($0) },
+                scheduleAfter: { delay, action in
+                    DispatchQueue.main.asyncAfter(deadline: .now() + delay, execute: action)
+                }
+            )
+        }
+    }
+
    // Provide BLE short peer ID for BitChat embedding
    var senderPeerID = PeerID(str: "")

@@ -16,9 +43,64 @@ final class NostrTransport: Transport {
    private var isSendingReadAcks = false
    private let readAckInterval: TimeInterval = TransportConfig.nostrReadAckInterval
    private let keychain: KeychainManagerProtocol
+    private let idBridge: NostrIdentityBridge
+    private let dependencies: Dependencies
+    private var favoriteStatusObserver: NSObjectProtocol?

-    init(keychain: KeychainManagerProtocol) {
+    // Reachability Cache (thread-safe)
+    private var reachablePeers: Set<PeerID> = []
+    private let queue = DispatchQueue(label: "nostr.transport.state", attributes: .concurrent)
+
+    @MainActor
+    init(
+        keychain: KeychainManagerProtocol,
+        idBridge: NostrIdentityBridge,
+        dependencies: Dependencies? = nil
+    ) {
        self.keychain = keychain
+        self.idBridge = idBridge
+        self.dependencies = dependencies ?? .live(idBridge: idBridge)
+        
+        setupObservers()
+        
+        // Synchronously warm the cache to avoid startup race
+        let favorites = self.dependencies.loadFavorites()
+        let reachable = favorites.values
+            .filter { $0.peerNostrPublicKey != nil }
+            .map { PeerID(publicKey: $0.peerNoisePublicKey) }
+            
+        queue.sync(flags: .barrier) {
+            self.reachablePeers = Set(reachable)
+        }
+    }
+
+    deinit {
+        if let favoriteStatusObserver {
+            dependencies.notificationCenter.removeObserver(favoriteStatusObserver)
+        }
+    }
+
+    private func setupObservers() {
+        favoriteStatusObserver = dependencies.notificationCenter.addObserver(
+            forName: .favoriteStatusChanged,
+            object: nil,
+            queue: nil
+        ) { [weak self] _ in
+            self?.refreshReachablePeers()
+        }
+    }
+
+    private func refreshReachablePeers() {
+        Task { @MainActor in
+            let favorites = dependencies.loadFavorites()
+            let reachable = favorites.values
+                .filter { $0.peerNostrPublicKey != nil }
+                .map { PeerID(publicKey: $0.peerNoisePublicKey) }
+            
+            self.queue.async(flags: .barrier) { [weak self] in
+                self?.reachablePeers = Set(reachable)
+            }
+        }
    }

    // MARK: - Transport Protocol Conformance
@@ -40,7 +122,19 @@ final class NostrTransport: Transport {
    func emergencyDisconnectAll() { /* no-op */ }

    func isPeerConnected(_ peerID: PeerID) -> Bool { false }
-    func isPeerReachable(_ peerID: PeerID) -> Bool { false }
+    
+    func isPeerReachable(_ peerID: PeerID) -> Bool {
+        queue.sync {
+            // Check if exact match
+            if reachablePeers.contains(peerID) { return true }
+            // Check for short ID match
+            if peerID.isShort {
+                return reachablePeers.contains(where: { $0.toShort() == peerID })
+            }
+            return false
+        }
+    }
+    
    func peerNickname(peerID: PeerID) -> String? { nil }
    func getPeerNicknames() -> [PeerID : String] { [:] }

@@ -64,89 +158,54 @@ final class NostrTransport: Transport {

    func sendPrivateMessage(_ content: String, to peerID: PeerID, recipientNickname: String, messageID: String) {
        Task { @MainActor in
-            guard let recipientNpub = resolveRecipientNpub(for: peerID) else { return }
-            guard let senderIdentity = try? NostrIdentityBridge.getCurrentNostrIdentity() else { return }
-            SecureLogger.debug("NostrTransport: preparing PM to \(recipientNpub.prefix(16))… for peerID \(peerID.id.prefix(8))… id=\(messageID.prefix(8))…", category: .session)
-            // Convert recipient npub -> hex (x-only)
-            let recipientHex: String
-            do {
-                let (hrp, data) = try Bech32.decode(recipientNpub)
-                guard hrp == "npub" else {
-                    SecureLogger.error("NostrTransport: recipient key not npub (hrp=\(hrp))", category: .session)
-                    return
-                }
-                recipientHex = data.hexEncodedString()
-            } catch {
-                SecureLogger.error("NostrTransport: failed to decode npub -> hex: \(error)", category: .session)
-                return
-            }
-            guard let embedded = NostrEmbeddedBitChat.encodePMForNostr(content: content, messageID: messageID, recipientPeerID: peerID.id, senderPeerID: senderPeerID.id) else {
+            guard let recipientNpub = resolveRecipientNpub(for: peerID),
+                  let recipientHex = npubToHex(recipientNpub),
+                  let senderIdentity = try? dependencies.currentIdentity() else { return }
+            SecureLogger.debug("NostrTransport: preparing PM to \(recipientNpub.prefix(16))… id=\(messageID.prefix(8))…", category: .session)
+            guard let embedded = NostrEmbeddedBitChat.encodePMForNostr(content: content, messageID: messageID, recipientPeerID: peerID, senderPeerID: senderPeerID) else {
                SecureLogger.error("NostrTransport: failed to embed PM packet", category: .session)
                return
            }
-            guard let event = try? NostrProtocol.createPrivateMessage(content: embedded, recipientPubkey: recipientHex, senderIdentity: senderIdentity) else {
-                SecureLogger.error("NostrTransport: failed to build Nostr event for PM", category: .session)
-                return
-            }
-            SecureLogger.debug("NostrTransport: sending PM giftWrap id=\(event.id.prefix(16))…", category: .session)
-            NostrRelayManager.shared.sendEvent(event)
+            sendWrappedMessage(content: embedded, recipientHex: recipientHex, senderIdentity: senderIdentity)
        }
    }

    func sendReadReceipt(_ receipt: ReadReceipt, to peerID: PeerID) {
        // Enqueue and process with throttling to avoid relay rate limits
-        readQueue.append(QueuedRead(receipt: receipt, peerID: peerID))
-        processReadQueueIfNeeded()
+        // Use barrier to synchronize access to readQueue
+        queue.async(flags: .barrier) { [weak self] in
+            self?.readQueue.append(QueuedRead(receipt: receipt, peerID: peerID))
+            self?.processReadQueueIfNeeded()
+        }
    }

    func sendFavoriteNotification(to peerID: PeerID, isFavorite: Bool) {
        Task { @MainActor in
-            guard let recipientNpub = resolveRecipientNpub(for: peerID) else { return }
-            guard let senderIdentity = try? NostrIdentityBridge.getCurrentNostrIdentity() else { return }
+            guard let recipientNpub = resolveRecipientNpub(for: peerID),
+                  let recipientHex = npubToHex(recipientNpub),
+                  let senderIdentity = try? dependencies.currentIdentity() else { return }
            let content = isFavorite ? "[FAVORITED]:\(senderIdentity.npub)" : "[UNFAVORITED]:\(senderIdentity.npub)"
            SecureLogger.debug("NostrTransport: preparing FAVORITE(\(isFavorite)) to \(recipientNpub.prefix(16))…", category: .session)
-            // Convert recipient npub -> hex
-            let recipientHex: String
-            do {
-                let (hrp, data) = try Bech32.decode(recipientNpub)
-                guard hrp == "npub" else { return }
-                recipientHex = data.hexEncodedString()
-            } catch { return }
-            guard let embedded = NostrEmbeddedBitChat.encodePMForNostr(content: content, messageID: UUID().uuidString, recipientPeerID: peerID.id, senderPeerID: senderPeerID.id) else {
+            guard let embedded = NostrEmbeddedBitChat.encodePMForNostr(content: content, messageID: UUID().uuidString, recipientPeerID: peerID, senderPeerID: senderPeerID) else {
                SecureLogger.error("NostrTransport: failed to embed favorite notification", category: .session)
                return
            }
-            guard let event = try? NostrProtocol.createPrivateMessage(content: embedded, recipientPubkey: recipientHex, senderIdentity: senderIdentity) else {
-                SecureLogger.error("NostrTransport: failed to build Nostr event for favorite notification", category: .session)
-                return
-            }
-            SecureLogger.debug("NostrTransport: sending favorite giftWrap id=\(event.id.prefix(16))…", category: .session)
-            NostrRelayManager.shared.sendEvent(event)
+            sendWrappedMessage(content: embedded, recipientHex: recipientHex, senderIdentity: senderIdentity)
        }
    }

    func sendBroadcastAnnounce() { /* no-op for Nostr */ }
    func sendDeliveryAck(for messageID: String, to peerID: PeerID) {
        Task { @MainActor in
-            guard let recipientNpub = resolveRecipientNpub(for: peerID) else { return }
-            guard let senderIdentity = try? NostrIdentityBridge.getCurrentNostrIdentity() else { return }
-            SecureLogger.debug("NostrTransport: preparing DELIVERED ack for id=\(messageID.prefix(8))… to \(recipientNpub.prefix(16))…", category: .session)
-            let recipientHex: String
-            do {
-                let (hrp, data) = try Bech32.decode(recipientNpub)
-                guard hrp == "npub" else { return }
-                recipientHex = data.hexEncodedString()
-            } catch { return }
-            guard let ack = NostrEmbeddedBitChat.encodeAckForNostr(type: .delivered, messageID: messageID, recipientPeerID: peerID.id, senderPeerID: senderPeerID.id) else {
+            guard let recipientNpub = resolveRecipientNpub(for: peerID),
+                  let recipientHex = npubToHex(recipientNpub),
+                  let senderIdentity = try? dependencies.currentIdentity() else { return }
+            SecureLogger.debug("NostrTransport: preparing DELIVERED ack id=\(messageID.prefix(8))…", category: .session)
+            guard let ack = NostrEmbeddedBitChat.encodeAckForNostr(type: .delivered, messageID: messageID, recipientPeerID: peerID, senderPeerID: senderPeerID) else {
                SecureLogger.error("NostrTransport: failed to embed DELIVERED ack", category: .session)
                return
            }
-            guard let event = try? NostrProtocol.createPrivateMessage(content: ack, recipientPubkey: recipientHex, senderIdentity: senderIdentity) else {
-                SecureLogger.error("NostrTransport: failed to build Nostr event for DELIVERED ack", category: .session)
-                return
-            }
-            SecureLogger.debug("NostrTransport: sending DELIVERED ack giftWrap id=\(event.id.prefix(16))…", category: .session)
-            NostrRelayManager.shared.sendEvent(event)
+            sendWrappedMessage(content: ack, recipientHex: recipientHex, senderIdentity: senderIdentity)
        }
    }
 }
@@ -158,21 +217,17 @@ extension NostrTransport {
    // MARK: Geohash ACK helpers
    func sendDeliveryAckGeohash(for messageID: String, toRecipientHex recipientHex: String, from identity: NostrIdentity) {
        Task { @MainActor in
-            SecureLogger.debug("GeoDM: send DELIVERED -> recip=\(recipientHex.prefix(8))… mid=\(messageID.prefix(8))… from=\(identity.publicKeyHex.prefix(8))…", category: .session)
-            guard let embedded = NostrEmbeddedBitChat.encodeAckForNostrNoRecipient(type: .delivered, messageID: messageID, senderPeerID: senderPeerID.id) else { return }
-            guard let event = try? NostrProtocol.createPrivateMessage(content: embedded, recipientPubkey: recipientHex, senderIdentity: identity) else { return }
-            NostrRelayManager.registerPendingGiftWrap(id: event.id)
-            NostrRelayManager.shared.sendEvent(event)
+            SecureLogger.debug("GeoDM: send DELIVERED mid=\(messageID.prefix(8))…", category: .session)
+            guard let embedded = NostrEmbeddedBitChat.encodeAckForNostrNoRecipient(type: .delivered, messageID: messageID, senderPeerID: senderPeerID) else { return }
+            sendWrappedMessage(content: embedded, recipientHex: recipientHex, senderIdentity: identity, registerPending: true)
        }
    }

    func sendReadReceiptGeohash(_ messageID: String, toRecipientHex recipientHex: String, from identity: NostrIdentity) {
        Task { @MainActor in
-            SecureLogger.debug("GeoDM: send READ -> recip=\(recipientHex.prefix(8))… mid=\(messageID.prefix(8))… from=\(identity.publicKeyHex.prefix(8))…", category: .session)
-            guard let embedded = NostrEmbeddedBitChat.encodeAckForNostrNoRecipient(type: .readReceipt, messageID: messageID, senderPeerID: senderPeerID.id) else { return }
-            guard let event = try? NostrProtocol.createPrivateMessage(content: embedded, recipientPubkey: recipientHex, senderIdentity: identity) else { return }
-            NostrRelayManager.registerPendingGiftWrap(id: event.id)
-            NostrRelayManager.shared.sendEvent(event)
+            SecureLogger.debug("GeoDM: send READ mid=\(messageID.prefix(8))…", category: .session)
+            guard let embedded = NostrEmbeddedBitChat.encodeAckForNostrNoRecipient(type: .readReceipt, messageID: messageID, senderPeerID: senderPeerID) else { return }
+            sendWrappedMessage(content: embedded, recipientHex: recipientHex, senderIdentity: identity, registerPending: true)
        }
    }

@@ -180,19 +235,12 @@ extension NostrTransport {
    func sendPrivateMessageGeohash(content: String, toRecipientHex recipientHex: String, from identity: NostrIdentity, messageID: String) {
        Task { @MainActor in
            guard !recipientHex.isEmpty else { return }
-            SecureLogger.debug("GeoDM: send PM -> recip=\(recipientHex.prefix(8))… mid=\(messageID.prefix(8))… from=\(identity.publicKeyHex.prefix(8))…", category: .session)
-            // Build embedded BitChat packet without recipient peer ID
-            guard let embedded = NostrEmbeddedBitChat.encodePMForNostrNoRecipient(content: content, messageID: messageID, senderPeerID: senderPeerID.id) else {
+            SecureLogger.debug("GeoDM: send PM mid=\(messageID.prefix(8))…", category: .session)
+            guard let embedded = NostrEmbeddedBitChat.encodePMForNostrNoRecipient(content: content, messageID: messageID, senderPeerID: senderPeerID) else {
                SecureLogger.error("NostrTransport: failed to embed geohash PM packet", category: .session)
                return
            }
-            guard let event = try? NostrProtocol.createPrivateMessage(content: embedded, recipientPubkey: recipientHex, senderIdentity: identity) else {
-                SecureLogger.error("NostrTransport: failed to build Nostr event for geohash PM", category: .session)
-                return
-            }
-            SecureLogger.debug("NostrTransport: sending geohash PM giftWrap id=\(event.id.prefix(16))…", category: .session)
-            NostrRelayManager.registerPendingGiftWrap(id: event.id)
-            NostrRelayManager.shared.sendEvent(event)
+            sendWrappedMessage(content: embedded, recipientHex: recipientHex, senderIdentity: identity, registerPending: true)
        }
    }
 }
@@ -200,58 +248,75 @@ extension NostrTransport {
 // MARK: - Private Helpers

 extension NostrTransport {
+    /// Converts npub bech32 string to hex pubkey
+    @MainActor
+    private func npubToHex(_ npub: String) -> String? {
+        do {
+            let (hrp, data) = try Bech32.decode(npub)
+            guard hrp == "npub" else { return nil }
+            return data.hexEncodedString()
+        } catch {
+            SecureLogger.error("NostrTransport: failed to decode npub -> hex: \(error)", category: .session)
+            return nil
+        }
+    }
+
+    /// Creates and sends a gift-wrapped private message event
+    @MainActor
+    private func sendWrappedMessage(content: String, recipientHex: String, senderIdentity: NostrIdentity, registerPending: Bool = false) {
+        guard let event = try? NostrProtocol.createPrivateMessage(content: content, recipientPubkey: recipientHex, senderIdentity: senderIdentity) else {
+            SecureLogger.error("NostrTransport: failed to build Nostr event", category: .session)
+            return
+        }
+        if registerPending {
+            dependencies.registerPendingGiftWrap(event.id)
+        }
+        dependencies.sendEvent(event)
+    }
+
+    /// Must be called within a barrier on `queue`
    private func processReadQueueIfNeeded() {
        guard !isSendingReadAcks else { return }
        guard !readQueue.isEmpty else { return }
        isSendingReadAcks = true
-        sendNextReadAck()
+        let item = readQueue.removeFirst()
+        sendReadAckItem(item)
    }

-    private func sendNextReadAck() {
-        guard !readQueue.isEmpty else { isSendingReadAcks = false; return }
-        let item = readQueue.removeFirst()
+    /// Sends a single read ack item (called after extraction from queue within barrier)
+    private func sendReadAckItem(_ item: QueuedRead) {
        Task { @MainActor in
-            guard let recipientNpub = resolveRecipientNpub(for: item.peerID) else { scheduleNextReadAck(); return }
-            guard let senderIdentity = try? NostrIdentityBridge.getCurrentNostrIdentity() else { scheduleNextReadAck(); return }
-            SecureLogger.debug("NostrTransport: preparing READ ack for id=\(item.receipt.originalMessageID.prefix(8))… to \(recipientNpub.prefix(16))…", category: .session)
-            // Convert recipient npub -> hex
-            let recipientHex: String
-            do {
-                let (hrp, data) = try Bech32.decode(recipientNpub)
-                guard hrp == "npub" else { scheduleNextReadAck(); return }
-                recipientHex = data.hexEncodedString()
-            } catch { scheduleNextReadAck(); return }
-            guard let ack = NostrEmbeddedBitChat.encodeAckForNostr(type: .readReceipt, messageID: item.receipt.originalMessageID, recipientPeerID: item.peerID.id, senderPeerID: senderPeerID.id) else {
+            defer { scheduleNextReadAck() }
+            guard let recipientNpub = resolveRecipientNpub(for: item.peerID),
+                  let recipientHex = npubToHex(recipientNpub),
+                  let senderIdentity = try? dependencies.currentIdentity() else { return }
+            SecureLogger.debug("NostrTransport: preparing READ ack id=\(item.receipt.originalMessageID.prefix(8))…", category: .session)
+            guard let ack = NostrEmbeddedBitChat.encodeAckForNostr(type: .readReceipt, messageID: item.receipt.originalMessageID, recipientPeerID: item.peerID, senderPeerID: senderPeerID) else {
                SecureLogger.error("NostrTransport: failed to embed READ ack", category: .session)
-                scheduleNextReadAck(); return
+                return
            }
-            guard let event = try? NostrProtocol.createPrivateMessage(content: ack, recipientPubkey: recipientHex, senderIdentity: senderIdentity) else {
-                SecureLogger.error("NostrTransport: failed to build Nostr event for READ ack", category: .session)
-                scheduleNextReadAck(); return
-            }
-            SecureLogger.debug("NostrTransport: sending READ ack giftWrap id=\(event.id.prefix(16))…", category: .session)
-            NostrRelayManager.shared.sendEvent(event)
-            scheduleNextReadAck()
+            sendWrappedMessage(content: ack, recipientHex: recipientHex, senderIdentity: senderIdentity)
        }
    }

    private func scheduleNextReadAck() {
-        DispatchQueue.main.asyncAfter(deadline: .now() + readAckInterval) { [weak self] in
-            guard let self = self else { return }
-            self.isSendingReadAcks = false
-            self.processReadQueueIfNeeded()
+        dependencies.scheduleAfter(readAckInterval) { [weak self] in
+            self?.queue.async(flags: .barrier) { [weak self] in
+                self?.isSendingReadAcks = false
+                self?.processReadQueueIfNeeded()
+            }
        }
    }

    @MainActor
    private func resolveRecipientNpub(for peerID: PeerID) -> String? {
        if let noiseKey = Data(hexString: peerID.id),
-           let fav = FavoritesPersistenceService.shared.getFavoriteStatus(for: noiseKey),
+           let fav = dependencies.favoriteStatusForNoiseKey(noiseKey),
           let npub = fav.peerNostrPublicKey {
            return npub
        }
        if peerID.id.count == 16,
-           let fav = FavoritesPersistenceService.shared.getFavoriteStatus(forPeerID: peerID),
+           let fav = dependencies.favoriteStatusForPeerID(peerID),
           let npub = fav.peerNostrPublicKey {
            return npub
        }
@@ -6,6 +6,7 @@
 // For more information, see <https://unlicense.org>
 //

+import BitFoundation
 import Foundation
 import UserNotifications
 #if os(iOS)
@@ -14,13 +15,103 @@ import UIKit
 import AppKit
 #endif

+protocol NotificationAuthorizing {
+    func requestAuthorization(
+        options: UNAuthorizationOptions,
+        completionHandler: @escaping (Bool, Error?) -> Void
+    )
+}
+
+protocol NotificationRequestDelivering {
+    func add(_ request: UNNotificationRequest)
+}
+
+private final class NotificationCenterAuthorizerAdapter: NotificationAuthorizing {
+    private let center: UNUserNotificationCenter
+
+    init(center: UNUserNotificationCenter) {
+        self.center = center
+    }
+
+    func requestAuthorization(
+        options: UNAuthorizationOptions,
+        completionHandler: @escaping (Bool, Error?) -> Void
+    ) {
+        center.requestAuthorization(options: options, completionHandler: completionHandler)
+    }
+}
+
+private final class NotificationCenterRequestDelivererAdapter: NotificationRequestDelivering {
+    private let center: UNUserNotificationCenter
+
+    init(center: UNUserNotificationCenter) {
+        self.center = center
+    }
+
+    func add(_ request: UNNotificationRequest) {
+        Task {
+            try? await center.add(request)
+        }
+    }
+}
+
+private struct NoopNotificationAuthorizer: NotificationAuthorizing {
+    func requestAuthorization(
+        options: UNAuthorizationOptions,
+        completionHandler: @escaping (Bool, Error?) -> Void
+    ) {
+        completionHandler(false, nil)
+    }
+}
+
+private struct NoopNotificationRequestDeliverer: NotificationRequestDelivering {
+    func add(_ request: UNNotificationRequest) {}
+}
+
 final class NotificationService {
    static let shared = NotificationService()
-    
-    private init() {}
-    
+
+    private let isRunningTestsProvider: () -> Bool
+    private let authorizer: NotificationAuthorizing
+    private let requestDeliverer: NotificationRequestDelivering
+
+    /// Returns true if running in test environment (XCTest, Swift Testing, or CI)
+    private var isRunningTests: Bool {
+        isRunningTestsProvider()
+    }
+
+    private init() {
+        self.isRunningTestsProvider = {
+            let env = ProcessInfo.processInfo.environment
+            return NSClassFromString("XCTestCase") != nil ||
+                   env["XCTestConfigurationFilePath"] != nil ||
+                   env["XCTestBundlePath"] != nil ||
+                   env["GITHUB_ACTIONS"] != nil ||
+                   env["CI"] != nil
+        }
+        if isRunningTestsProvider() {
+            self.authorizer = NoopNotificationAuthorizer()
+            self.requestDeliverer = NoopNotificationRequestDeliverer()
+        } else {
+            let center = UNUserNotificationCenter.current()
+            self.authorizer = NotificationCenterAuthorizerAdapter(center: center)
+            self.requestDeliverer = NotificationCenterRequestDelivererAdapter(center: center)
+        }
+    }
+
+    internal init(
+        isRunningTestsProvider: @escaping () -> Bool,
+        authorizer: NotificationAuthorizing,
+        requestDeliverer: NotificationRequestDelivering
+    ) {
+        self.isRunningTestsProvider = isRunningTestsProvider
+        self.authorizer = authorizer
+        self.requestDeliverer = requestDeliverer
+    }
+
    func requestAuthorization() {
-        UNUserNotificationCenter.current().requestAuthorization(options: [.alert, .sound, .badge]) { granted, error in
+        guard !isRunningTests else { return }
+        authorizer.requestAuthorization(options: [.alert, .sound, .badge]) { granted, error in
            if granted {
                // Permission granted
            } else {
@@ -29,28 +120,31 @@ final class NotificationService {
        }
    }
    
-    func sendLocalNotification(title: String, body: String, identifier: String, userInfo: [String: Any]? = nil) {
-        // For now, skip app state check entirely to avoid thread issues
-        // The NotificationDelegate will handle foreground presentation
-        DispatchQueue.main.async {
-            let content = UNMutableNotificationContent()
-            content.title = title
-            content.body = body
-            content.sound = .default
-            if let userInfo = userInfo {
-                content.userInfo = userInfo
-            }
-            
-            let request = UNNotificationRequest(
-                identifier: identifier,
-                content: content,
-                trigger: nil // Deliver immediately
-            )
-            
-            UNUserNotificationCenter.current().add(request) { _ in
-                // Notification added
-            }
+    func sendLocalNotification(
+        title: String,
+        body: String,
+        identifier: String,
+        userInfo: [String: Any]? = nil,
+        interruptionLevel: UNNotificationInterruptionLevel = .active
+    ) {
+        guard !isRunningTests else { return }
+        let content = UNMutableNotificationContent()
+        content.title = title
+        content.body = body
+        content.sound = .default
+        content.interruptionLevel = interruptionLevel
+
+        if let userInfo = userInfo {
+            content.userInfo = userInfo
        }
+
+        let request = UNNotificationRequest(
+            identifier: identifier,
+            content: content,
+            trigger: nil // Deliver immediately
+        )
+
+        requestDeliverer.add(request)
    }
    
    func sendMentionNotification(from sender: String, message: String) {
@@ -61,11 +155,11 @@ final class NotificationService {
        sendLocalNotification(title: title, body: body, identifier: identifier)
    }
    
-    func sendPrivateMessageNotification(from sender: String, message: String, peerID: String) {
+    func sendPrivateMessageNotification(from sender: String, message: String, peerID: PeerID) {
        let title = "🔒 DM from \(sender)"
        let body = message
        let identifier = "private-\(UUID().uuidString)"
-        let userInfo = ["peerID": peerID, "senderName": sender]
+        let userInfo = ["peerID": peerID.id, "senderName": sender]
        
        sendLocalNotification(title: title, body: body, identifier: identifier, userInfo: userInfo)
    }
@@ -82,26 +176,14 @@ final class NotificationService {
    func sendNetworkAvailableNotification(peerCount: Int) {
        let title = "👥 bitchatters nearby!"
        let body = peerCount == 1 ? "1 person around" : "\(peerCount) people around"
-        let identifier = "network-available-\(Date().timeIntervalSince1970)"
-        
-        // For network notifications, we want to show them even in foreground
-        // No app state check - let the notification delegate handle presentation
-        DispatchQueue.main.async {
-            let content = UNMutableNotificationContent()
-            content.title = title
-            content.body = body
-            content.sound = .default
-            content.interruptionLevel = .timeSensitive  // Make it more prominent
-            
-            let request = UNNotificationRequest(
-                identifier: identifier,
-                content: content,
-                trigger: nil // Deliver immediately
-            )
-            
-            UNUserNotificationCenter.current().add(request) { _ in
-                // Notification added
-            }
-        }
+        // Fixed identifier so iOS updates the existing notification instead of creating new ones
+        let identifier = "network-available"
+
+        sendLocalNotification(
+            title: title,
+            body: body,
+            identifier: identifier,
+            interruptionLevel: .timeSensitive
+        )
    }
 }
@@ -6,10 +6,19 @@
 // For more information, see <https://unlicense.org>
 //

+import BitLogger
 import Foundation

 struct NotificationStreamAssembler {
    private var buffer = Data()
+    private var pendingFrameStartedAt: DispatchTime?
+    private var pendingFrameExpectedLength: Int = 0
+
+    private mutating func resetState() {
+        buffer.removeAll(keepingCapacity: false)
+        pendingFrameStartedAt = nil
+        pendingFrameExpectedLength = 0
+    }

    mutating func append(_ chunk: Data) -> (frames: [Data], droppedPrefixes: [UInt8], reset: Bool) {
        guard !chunk.isEmpty else { return ([], [], false) }
@@ -18,64 +27,117 @@ struct NotificationStreamAssembler {

        var frames: [Data] = []
        var dropped: [UInt8] = []
-        var reset = false
-        let maxFrameLength = TransportConfig.blePendingWriteBufferCapBytes
+        var didReset = false
+        let now = DispatchTime.now()
+        let maxFrameLength = TransportConfig.bleNotificationAssemblerHardCapBytes
+        let minimumFramePrefix = BinaryProtocol.v1HeaderSize + BinaryProtocol.senderIDSize

-        let minHeaderBytes = 14 // version + type + ttl + timestamp(8) + flags + length(2)
-        let minFramePrefix = minHeaderBytes + BinaryProtocol.senderIDSize
+        if buffer.count > TransportConfig.bleNotificationAssemblerHardCapBytes {
+            SecureLogger.error("❌ Notification assembler overflow (\(buffer.count) bytes); dropping partial frame", category: .session)
+            resetState()
+            return ([], [], true)
+        }

-        while buffer.count >= minFramePrefix {
-            guard let first = buffer.first else { break }
-            if first != 1 {
+        while buffer.count >= minimumFramePrefix {
+            guard let version = buffer.first else { break }
+            guard version == 1 || version == 2 else {
                dropped.append(buffer.removeFirst())
+                pendingFrameStartedAt = nil
+                pendingFrameExpectedLength = 0
                continue
            }

-            guard buffer.count >= minHeaderBytes else { break }
+            guard let headerSize = BinaryProtocol.headerSize(for: version) else {
+                dropped.append(buffer.removeFirst())
+                pendingFrameStartedAt = nil
+                pendingFrameExpectedLength = 0
+                continue
+            }
+            let framePrefix = headerSize + BinaryProtocol.senderIDSize
+            guard buffer.count >= framePrefix else { break }

-            let headerBytes = Array(buffer.prefix(minFramePrefix))
-            guard headerBytes.count == minFramePrefix else { break }
-
-            let flags = headerBytes[11]
+            let flagsIndex = buffer.startIndex + BinaryProtocol.Offsets.flags
+            guard flagsIndex < buffer.endIndex else { break }
+            let flags = buffer[flagsIndex]
            let hasRecipient = (flags & BinaryProtocol.Flags.hasRecipient) != 0
            let hasSignature = (flags & BinaryProtocol.Flags.hasSignature) != 0
-            let payloadLen = (Int(headerBytes[12]) << 8) | Int(headerBytes[13])
+            let isCompressed = (flags & BinaryProtocol.Flags.isCompressed) != 0
+            let hasRoute = (version >= 2) && (flags & BinaryProtocol.Flags.hasRoute) != 0

-            var frameLength = minFramePrefix + payloadLen
+            let lengthOffset = 12
+            let payloadLength: Int
+            if version == 2 {
+                let lengthIndex = buffer.startIndex + lengthOffset
+                payloadLength =
+                    (Int(buffer[lengthIndex]) << 24) |
+                    (Int(buffer[lengthIndex + 1]) << 16) |
+                    (Int(buffer[lengthIndex + 2]) << 8) |
+                    Int(buffer[lengthIndex + 3])
+            } else {
+                let lengthIndex = buffer.startIndex + lengthOffset
+                payloadLength = (Int(buffer[lengthIndex]) << 8) | Int(buffer[lengthIndex + 1])
+            }
+
+            var frameLength = framePrefix + payloadLength
            if hasRecipient { frameLength += BinaryProtocol.recipientIDSize }
            if hasSignature { frameLength += BinaryProtocol.signatureSize }
+            
+            if hasRoute {
+                let routeCountOffset = framePrefix + (hasRecipient ? BinaryProtocol.recipientIDSize : 0)
+                let routeCountIndex = buffer.startIndex + routeCountOffset
+                guard buffer.count > routeCountOffset else { break }
+                let routeCount = Int(buffer[routeCountIndex])
+                frameLength += 1 + (routeCount * BinaryProtocol.senderIDSize)
+            }
+            
+            if isCompressed {
+                let rawLengthFieldBytes = (version == 2) ? 4 : 2
+                if payloadLength < rawLengthFieldBytes {
+                    SecureLogger.error("❌ Invalid compressed payload length (\(payloadLength))", category: .session)
+                    resetState()
+                    didReset = true
+                    break
+                }
+            }

            guard frameLength > 0, frameLength <= maxFrameLength else {
-                buffer.removeAll()
-                reset = true
+                SecureLogger.error("❌ Notification frame length \(frameLength) invalid (cap=\(maxFrameLength)); resetting stream", category: .session)
+                resetState()
+                didReset = true
                break
            }

            if buffer.count < frameLength {
-                // Check if a new frame start exists within the incomplete buffer; if so, drop leading partial bytes.
-                if let nextStart = buffer.dropFirst().firstIndex(of: 1) {
-                    let dropCount = buffer.distance(from: buffer.startIndex, to: nextStart)
-                    if dropCount > 0 {
-                        buffer.removeFirst(dropCount)
-                        dropped.append(1) // treat as dropped partial start
+                let remaining = frameLength - buffer.count
+                if pendingFrameStartedAt == nil || frameLength != pendingFrameExpectedLength {
+                    pendingFrameStartedAt = now
+                    pendingFrameExpectedLength = frameLength
+                } else if let started = pendingFrameStartedAt {
+                    let elapsed = now.uptimeNanoseconds - started.uptimeNanoseconds
+                    let threshold = UInt64(TransportConfig.bleAssemblerStallResetMs) * 1_000_000
+                    if elapsed >= threshold {
+                        SecureLogger.debug("📉 Resetting notification assembler after waiting \(remaining)B for \(TransportConfig.bleAssemblerStallResetMs)ms", category: .session)
+                        resetState()
+                        didReset = true
+                    } else {
+                        SecureLogger.debug("⌛ Waiting for remaining \(remaining)B to complete BLE frame", category: .session)
                    }
                }
                break
            }

+            pendingFrameStartedAt = nil
+            pendingFrameExpectedLength = 0
+
            let frame = Data(buffer.prefix(frameLength))
            frames.append(frame)
            buffer.removeFirst(frameLength)
        }

        if !buffer.isEmpty, buffer.allSatisfy({ $0 == 0 }) {
-            buffer.removeAll(keepingCapacity: false)
+            resetState()
        }

-        return (frames, dropped, reset)
-    }
-
-    mutating func reset() {
-        buffer.removeAll(keepingCapacity: false)
+        return (frames, dropped, didReset)
    }
 }
@@ -7,35 +7,190 @@
 //

 import BitLogger
+import BitFoundation
 import Foundation
 import SwiftUI

 /// Manages all private chat functionality
 final class PrivateChatManager: ObservableObject {
-    @Published var privateChats: [String: [BitchatMessage]] = [:]
-    @Published var selectedPeer: String? = nil
-    @Published var unreadMessages: Set<String> = []
-    
+    @Published var privateChats: [PeerID: [BitchatMessage]] = [:]
+    @Published var selectedPeer: PeerID? = nil
+    @Published var unreadMessages: Set<PeerID> = []
+
    private var selectedPeerFingerprint: String? = nil
    var sentReadReceipts: Set<String> = []  // Made accessible for ChatViewModel
-    
+
    weak var meshService: Transport?
    // Route acks/receipts via MessageRouter (chooses mesh or Nostr)
    weak var messageRouter: MessageRouter?
-    
+    // Peer service for looking up peer info during consolidation
+    weak var unifiedPeerService: UnifiedPeerService?
+
    init(meshService: Transport? = nil) {
        self.meshService = meshService
    }

    // Cap for messages stored per private chat
    private let privateChatCap = TransportConfig.privateChatCap
+
+    // MARK: - Message Consolidation
+
+    /// Consolidates messages from different peer ID representations into a single chat.
+    /// This ensures messages from stable Noise keys and temporary Nostr peer IDs are merged.
+    /// - Parameters:
+    ///   - peerID: The target peer ID to consolidate messages into
+    ///   - peerNickname: The peer's display name (lowercased for matching)
+    ///   - persistedReadReceipts: The persisted read receipts set from ChatViewModel (UserDefaults-backed)
+    /// - Returns: True if any unread messages were found during consolidation
+    @MainActor
+    func consolidateMessages(for peerID: PeerID, peerNickname: String, persistedReadReceipts: Set<String>) -> Bool {
+        guard let meshService = meshService else { return false }
+        var hasUnreadMessages = false
+
+        // 1. Consolidate from stable Noise key (64-char hex)
+        if let peer = unifiedPeerService?.getPeer(by: peerID) {
+            let noiseKeyHex = PeerID(hexData: peer.noisePublicKey)
+
+            if noiseKeyHex != peerID, let nostrMessages = privateChats[noiseKeyHex], !nostrMessages.isEmpty {
+                if privateChats[peerID] == nil {
+                    privateChats[peerID] = []
+                }
+
+                let existingMessageIds = Set(privateChats[peerID]?.map { $0.id } ?? [])
+                for message in nostrMessages {
+                    if !existingMessageIds.contains(message.id) {
+                        // Update senderPeerID for correct read receipts
+                        let updatedMessage = BitchatMessage(
+                            id: message.id,
+                            sender: message.sender,
+                            content: message.content,
+                            timestamp: message.timestamp,
+                            isRelay: message.isRelay,
+                            originalSender: message.originalSender,
+                            isPrivate: message.isPrivate,
+                            recipientNickname: message.recipientNickname,
+                            senderPeerID: message.senderPeerID == meshService.myPeerID ? meshService.myPeerID : peerID,
+                            mentions: message.mentions,
+                            deliveryStatus: message.deliveryStatus
+                        )
+                        privateChats[peerID]?.append(updatedMessage)
+
+                        // Check for recent unread messages (< 60s, not sent by us, not already read)
+                        // Use persistedReadReceipts to correctly identify already-read messages after app restart
+                        if message.senderPeerID != meshService.myPeerID {
+                            let messageAge = Date().timeIntervalSince(message.timestamp)
+                            if messageAge < 60 && !persistedReadReceipts.contains(message.id) {
+                                hasUnreadMessages = true
+                            }
+                        }
+                    }
+                }
+
+                privateChats[peerID]?.sort { $0.timestamp < $1.timestamp }
+
+                if hasUnreadMessages {
+                    unreadMessages.insert(peerID)
+                } else if unreadMessages.contains(noiseKeyHex) {
+                    unreadMessages.remove(noiseKeyHex)
+                }
+
+                privateChats.removeValue(forKey: noiseKeyHex)
+            }
+        }
+
+        // 2. Consolidate from temporary Nostr peer IDs (nostr_* prefixed)
+        let normalizedNickname = peerNickname.lowercased()
+        var tempPeerIDsToConsolidate: [PeerID] = []
+
+        for (storedPeerID, messages) in privateChats {
+            if storedPeerID.isGeoDM && storedPeerID != peerID {
+                let nicknamesMatch = messages.allSatisfy { $0.sender.lowercased() == normalizedNickname }
+                if nicknamesMatch && !messages.isEmpty {
+                    tempPeerIDsToConsolidate.append(storedPeerID)
+                }
+            }
+        }
+
+        if !tempPeerIDsToConsolidate.isEmpty {
+            if privateChats[peerID] == nil {
+                privateChats[peerID] = []
+            }
+
+            let existingMessageIds = Set(privateChats[peerID]?.map { $0.id } ?? [])
+            var consolidatedCount = 0
+            var hadUnreadTemp = false
+
+            for tempPeerID in tempPeerIDsToConsolidate {
+                if unreadMessages.contains(tempPeerID) {
+                    hadUnreadTemp = true
+                }
+
+                if let tempMessages = privateChats[tempPeerID] {
+                    for message in tempMessages {
+                        if !existingMessageIds.contains(message.id) {
+                            let updatedMessage = BitchatMessage(
+                                id: message.id,
+                                sender: message.sender,
+                                content: message.content,
+                                timestamp: message.timestamp,
+                                isRelay: message.isRelay,
+                                originalSender: message.originalSender,
+                                isPrivate: message.isPrivate,
+                                recipientNickname: message.recipientNickname,
+                                senderPeerID: peerID,
+                                mentions: message.mentions,
+                                deliveryStatus: message.deliveryStatus
+                            )
+                            privateChats[peerID]?.append(updatedMessage)
+                            consolidatedCount += 1
+                        }
+                    }
+                    privateChats.removeValue(forKey: tempPeerID)
+                    unreadMessages.remove(tempPeerID)
+                }
+            }
+
+            if hadUnreadTemp {
+                unreadMessages.insert(peerID)
+                hasUnreadMessages = true
+                SecureLogger.debug("📬 Transferred unread status from temp peer IDs to \(peerID)", category: .session)
+            }
+
+            if consolidatedCount > 0 {
+                privateChats[peerID]?.sort { $0.timestamp < $1.timestamp }
+                SecureLogger.info("📥 Consolidated \(consolidatedCount) Nostr messages from temporary peer IDs to \(peerNickname)", category: .session)
+            }
+        }
+
+        return hasUnreadMessages
+    }
+
+    /// Syncs the read receipt tracking between manager and view model for sent messages
+    @MainActor
+    func syncReadReceiptsForSentMessages(peerID: PeerID, nickname: String, externalReceipts: inout Set<String>) {
+        guard let messages = privateChats[peerID] else { return }
+
+        for message in messages {
+            if message.sender == nickname {
+                if let status = message.deliveryStatus {
+                    switch status {
+                    case .read, .delivered:
+                        externalReceipts.insert(message.id)
+                        sentReadReceipts.insert(message.id)
+                    case .failed, .partiallyDelivered, .sending, .sent:
+                        break
+                    }
+                }
+            }
+        }
+    }
    
    /// Start a private chat with a peer
-    func startChat(with peerID: String) {
+    func startChat(with peerID: PeerID) {
        selectedPeer = peerID
        
        // Store fingerprint for persistence across reconnections
-        if let fingerprint = meshService?.getFingerprint(for: PeerID(str: peerID)) {
+        if let fingerprint = meshService?.getFingerprint(for: peerID) {
            selectedPeerFingerprint = fingerprint
        }
        
@@ -55,7 +210,7 @@ final class PrivateChatManager: ObservableObject {
    }

    /// Remove duplicate messages by ID and keep chronological order
-    func sanitizeChat(for peerID: String) {
+    func sanitizeChat(for peerID: PeerID) {
        guard let arr = privateChats[peerID] else { return }
        if arr.count <= 1 {
            return
@@ -79,7 +234,7 @@ final class PrivateChatManager: ObservableObject {
    }
    
    /// Mark messages from a peer as read
-    func markAsRead(from peerID: String) {
+    func markAsRead(from peerID: PeerID) {
        unreadMessages.remove(peerID)
        
        // Send read receipts for unread messages that haven't been sent yet
@@ -105,7 +260,7 @@ final class PrivateChatManager: ObservableObject {
        // Create read receipt using the simplified method
        let receipt = ReadReceipt(
            originalMessageID: message.id,
-            readerID: meshService?.myPeerID.id ?? "",
+            readerID: meshService?.myPeerID ?? PeerID(str: ""),
            readerNickname: meshService?.myNickname ?? ""
        )
        
@@ -13,6 +13,7 @@ struct RelayController {
                       senderIsSelf: Bool,
                       isEncrypted: Bool,
                       isDirectedEncrypted: Bool,
+                       isFragment: Bool,
                       isDirectedFragment: Bool,
                       isHandshake: Bool,
                       isAnnounce: Bool,
@@ -36,6 +37,16 @@ struct RelayController {
            return RelayDecision(shouldRelay: true, newTTL: newTTL, delayMs: delayMs)
        }

+        if isFragment {
+            let ttlLimit = min(ttlCap, TransportConfig.bleFragmentRelayTtlCap)
+            guard ttlLimit > 1 else {
+                return RelayDecision(shouldRelay: false, newTTL: ttlLimit, delayMs: 0)
+            }
+            let newTTL = ttlLimit &- 1
+            let delayMs = Int.random(in: TransportConfig.bleFragmentRelayMinDelayMs...TransportConfig.bleFragmentRelayMaxDelayMs)
+            return RelayDecision(shouldRelay: true, newTTL: newTTL, delayMs: delayMs)
+        }
+
        // TTL clamping for broadcast
        // - Dense graphs: keep lower but still allow multi-hop bridging
        // - Announces get a bit more headroom
@@ -0,0 +1,65 @@
+import Foundation
+import Combine
+
+/// Centralized progress bus for Bluetooth file transfers.
+/// Emits Combine events consumed by ChatViewModel to update UI progress indicators.
+final class TransferProgressManager {
+    static let shared = TransferProgressManager()
+
+    enum Event {
+        case started(id: String, totalFragments: Int)
+        case updated(id: String, sentFragments: Int, totalFragments: Int)
+        case completed(id: String, totalFragments: Int)
+        case cancelled(id: String, sentFragments: Int, totalFragments: Int)
+    }
+
+    private let subject = PassthroughSubject<Event, Never>()
+    private let queue = DispatchQueue(label: "com.bitchat.transfer-progress", attributes: .concurrent)
+    private var states: [String: (sent: Int, total: Int)] = [:]
+
+    var publisher: AnyPublisher<Event, Never> {
+        subject.eraseToAnyPublisher()
+    }
+
+    func start(id: String, totalFragments: Int) {
+        queue.async(flags: .barrier) { [weak self] in
+            guard let self = self else { return }
+            self.states[id] = (sent: 0, total: totalFragments)
+            self.subject.send(.started(id: id, totalFragments: totalFragments))
+        }
+    }
+
+    func recordFragmentSent(id: String) {
+        queue.async(flags: .barrier) { [weak self] in
+            guard let self = self, var state = self.states[id] else { return }
+            state.sent = min(state.sent + 1, state.total)
+            self.states[id] = state
+            self.subject.send(.updated(id: id, sentFragments: state.sent, totalFragments: state.total))
+            if state.sent >= state.total {
+                self.states.removeValue(forKey: id)
+                self.subject.send(.completed(id: id, totalFragments: state.total))
+            }
+        }
+    }
+
+    func cancel(id: String) {
+        queue.async(flags: .barrier) { [weak self] in
+            guard let self = self, let state = self.states.removeValue(forKey: id) else { return }
+            self.subject.send(.cancelled(id: id, sentFragments: state.sent, totalFragments: state.total))
+        }
+    }
+
+    func reset(id: String) {
+        queue.async(flags: .barrier) { [weak self] in
+            self?.states.removeValue(forKey: id)
+        }
+    }
+
+    func snapshot(id: String) -> (sent: Int, total: Int)? {
+        var result: (sent: Int, total: Int)?
+        queue.sync {
+            result = states[id]
+        }
+        return result
+    }
+}
@@ -1,3 +1,4 @@
+import BitFoundation
 import Foundation
 import Combine

@@ -45,20 +46,38 @@ protocol Transport: AnyObject {

    // Messaging
    func sendMessage(_ content: String, mentions: [String])
+    func sendMessage(_ content: String, mentions: [String], messageID: String, timestamp: Date)
    func sendPrivateMessage(_ content: String, to peerID: PeerID, recipientNickname: String, messageID: String)
    func sendReadReceipt(_ receipt: ReadReceipt, to peerID: PeerID)
    func sendFavoriteNotification(to peerID: PeerID, isFavorite: Bool)
    func sendBroadcastAnnounce()
    func sendDeliveryAck(for messageID: String, to peerID: PeerID)
+    func sendFileBroadcast(_ packet: BitchatFilePacket, transferId: String)
+    func sendFilePrivate(_ packet: BitchatFilePacket, to peerID: PeerID, transferId: String)
+    func cancelTransfer(_ transferId: String)

    // QR verification (optional for transports)
    func sendVerifyChallenge(to peerID: PeerID, noiseKeyHex: String, nonceA: Data)
    func sendVerifyResponse(to peerID: PeerID, noiseKeyHex: String, nonceA: Data)
+
+    // Pending file management (BCH-01-002: files held in memory until user accepts)
+    func acceptPendingFile(id: String) -> URL?
+    func declinePendingFile(id: String)
 }

 extension Transport {
    func sendVerifyChallenge(to peerID: PeerID, noiseKeyHex: String, nonceA: Data) {}
    func sendVerifyResponse(to peerID: PeerID, noiseKeyHex: String, nonceA: Data) {}
+    func sendFileBroadcast(_ packet: BitchatFilePacket, transferId: String) {}
+    func sendFilePrivate(_ packet: BitchatFilePacket, to peerID: PeerID, transferId: String) {}
+    func cancelTransfer(_ transferId: String) {}
+
+    func sendMessage(_ content: String, mentions: [String], messageID: String, timestamp: Date) {
+        sendMessage(content, mentions: mentions)
+    }
+
+    func acceptPendingFile(id: String) -> URL? { nil }
+    func declinePendingFile(id: String) {}
 }

 protocol TransportPeerEventsDelegate: AnyObject {
@@ -8,6 +8,10 @@ enum TransportConfig {
    static let messageTTLDefault: UInt8 = 7                 // Default TTL for mesh flooding
    static let bleMaxInFlightAssemblies: Int = 128          // Cap concurrent fragment assemblies
    static let bleHighDegreeThreshold: Int = 6              // For adaptive TTL/probabilistic relays
+    static let bleMaxConcurrentTransfers: Int = 2           // Limit simultaneous large media sends
+    static let bleFragmentRelayMinDelayMs: Int = 8          // Faster forwarding for media fragments
+    static let bleFragmentRelayMaxDelayMs: Int = 25         // Upper jitter bound for fragment relays
+    static let bleFragmentRelayTtlCap: UInt8 = 5            // Clamp fragment TTL to contain floods

    // UI / Storage Caps
    static let privateChatCap: Int = 1337
@@ -17,6 +21,7 @@ enum TransportConfig {

    // Timers
    static let networkResetGraceSeconds: TimeInterval = 600 // 10 minutes
+    static let networkNotificationCooldownSeconds: TimeInterval = 300 // 5 minutes
    static let basePublicFlushInterval: TimeInterval = 0.08  // ~12.5 fps batching

    // BLE duty/announce/connect
@@ -30,7 +35,11 @@ enum TransportConfig {
    static let bleDynamicRSSIThresholdDefault: Int = -90
    static let bleConnectionCandidatesMax: Int = 100
    static let blePendingWriteBufferCapBytes: Int = 1_000_000
-    static let blePendingNotificationsCapCount: Int = 20
+    static let bleNotificationAssemblerHardCapBytes: Int = 8 * 1024 * 1024
+    static let bleAssemblerStallResetMs: Int = 250
+    static let blePendingNotificationsCapCount: Int = 128
+    static let bleNotificationRetryDelayMs: Int = 25
+    static let bleNotificationRetryMaxAttempts: Int = 80

    // Nostr
    static let nostrReadAckInterval: TimeInterval = 0.35 // ~3 per second
@@ -62,6 +71,7 @@ enum TransportConfig {
    static let uiAnimationMediumSeconds: TimeInterval = 0.2
    static let uiAnimationSidebarSeconds: TimeInterval = 0.25
    static let uiRecentCutoffFiveMinutesSeconds: TimeInterval = 5 * 60
+    static let uiMeshEmptyConfirmationSeconds: TimeInterval = 30.0

    // BLE maintenance & thresholds
    static let bleMaintenanceInterval: TimeInterval = 5.0
@@ -87,11 +97,12 @@ enum TransportConfig {
    // Keep scanning fully ON when we saw traffic very recently
    static let bleRecentTrafficForceScanSeconds: TimeInterval = 10.0
    static let bleThreadSleepWriteShortDelaySeconds: TimeInterval = 0.05
-    static let bleExpectedWritePerFragmentMs: Int = 8
-    static let bleExpectedWriteMaxMs: Int = 2000
-    // Faster fragment pacing; use slightly tighter spacing for directed trains
-    static let bleFragmentSpacingMs: Int = 5
-    static let bleFragmentSpacingDirectedMs: Int = 4
+    static let bleExpectedWritePerFragmentMs: Int = 20
+    static let bleExpectedWriteMaxMs: Int = 5000
+    // Fragment pacing: Conservative spacing to prevent BLE buffer overflow
+    // Aggressive pacing causes packet loss; needs 25-30ms between fragments for reliable delivery
+    static let bleFragmentSpacingMs: Int = 30
+    static let bleFragmentSpacingDirectedMs: Int = 25
    static let bleAnnounceIntervalSeconds: TimeInterval = 4.0
    static let bleDutyOnDurationDense: TimeInterval = 3.0
    static let bleDutyOffDurationDense: TimeInterval = 15.0
@@ -141,6 +152,9 @@ enum TransportConfig {

    // Geo relay directory
    static let geoRelayFetchIntervalSeconds: TimeInterval = 60 * 60 * 24
+    static let geoRelayRefreshCheckIntervalSeconds: TimeInterval = 60 * 60
+    static let geoRelayRetryInitialSeconds: TimeInterval = 60
+    static let geoRelayRetryMaxSeconds: TimeInterval = 60 * 60

    // BLE operational delays
    static let bleInitialAnnounceDelaySeconds: TimeInterval = 0.6
@@ -150,6 +164,14 @@ enum TransportConfig {
    static let blePostAnnounceDelaySeconds: TimeInterval = 0.4
    static let bleForceAnnounceMinIntervalSeconds: TimeInterval = 0.15

+    // BCH-01-004: Rate-limiting for subscription-triggered announces
+    // Prevents rapid enumeration attacks by rate-limiting announce responses
+    static let bleSubscriptionRateLimitMinSeconds: TimeInterval = 2.0       // Minimum interval between announces per central
+    static let bleSubscriptionRateLimitBackoffFactor: Double = 2.0          // Exponential backoff multiplier
+    static let bleSubscriptionRateLimitMaxBackoffSeconds: TimeInterval = 30.0  // Maximum backoff period
+    static let bleSubscriptionRateLimitWindowSeconds: TimeInterval = 60.0   // Window for tracking subscription attempts
+    static let bleSubscriptionRateLimitMaxAttempts: Int = 5                 // Max attempts before extended cooldown
+
    // Store-and-forward for directed packets at relays
    static let bleDirectedSpoolWindowSeconds: TimeInterval = 15.0

@@ -191,4 +213,18 @@ enum TransportConfig {
    static let uiShareExtensionDismissDelaySeconds: TimeInterval = 2.0
    static let uiShareAcceptWindowSeconds: TimeInterval = 30.0
    static let uiMigrationCutoffSeconds: TimeInterval = 24 * 60 * 60
+
+    // Gossip Sync Configuration
+    static let syncSeenCapacity: Int = 1000
+    static let syncGCSMaxBytes: Int = 400
+    static let syncGCSTargetFpr: Double = 0.01
+    static let syncMaxMessageAgeSeconds: TimeInterval = 900
+    static let syncMaintenanceIntervalSeconds: TimeInterval = 30.0
+    static let syncStalePeerCleanupIntervalSeconds: TimeInterval = 60.0
+    static let syncStalePeerTimeoutSeconds: TimeInterval = 60.0
+    static let syncFragmentCapacity: Int = 600
+    static let syncFileTransferCapacity: Int = 200
+    static let syncFragmentIntervalSeconds: TimeInterval = 30.0
+    static let syncFileTransferIntervalSeconds: TimeInterval = 60.0
+    static let syncMessageIntervalSeconds: TimeInterval = 15.0
 }
@@ -7,6 +7,7 @@
 //

 import BitLogger
+import BitFoundation
 import Foundation
 import Combine
 import SwiftUI
@@ -27,6 +28,7 @@ final class UnifiedPeerService: ObservableObject, TransportPeerEventsDelegate {
    private var peerIndex: [PeerID: BitchatPeer] = [:]
    private var fingerprintCache: [PeerID: String] = [:]
    private let meshService: Transport
+    private let idBridge: NostrIdentityBridge
    private let identityManager: SecureIdentityStateManagerProtocol
    weak var messageRouter: MessageRouter?
    private let favoritesService = FavoritesPersistenceService.shared
@@ -34,8 +36,13 @@ final class UnifiedPeerService: ObservableObject, TransportPeerEventsDelegate {
    
    // MARK: - Initialization
    
-    init(meshService: Transport, identityManager: SecureIdentityStateManagerProtocol) {
+    init(
+        meshService: Transport,
+        idBridge: NostrIdentityBridge,
+        identityManager: SecureIdentityStateManagerProtocol
+    ) {
        self.meshService = meshService
+        self.idBridge = idBridge
        self.identityManager = identityManager
        
        // Subscribe to changes from both services
@@ -229,10 +236,10 @@ final class UnifiedPeerService: ObservableObject, TransportPeerEventsDelegate {
    }
    
    /// Get peer ID for nickname
-    func getPeerID(for nickname: String) -> String? {
+    func getPeerID(for nickname: String) -> PeerID? {
        for peer in peers {
            if peer.displayName == nickname || peer.nickname == nickname {
-                return peer.peerID.id
+                return peer.peerID
            }
        }
        return nil
@@ -285,7 +292,7 @@ final class UnifiedPeerService: ObservableObject, TransportPeerEventsDelegate {
            var peerNostrKey = peer.nostrPublicKey
            if peerNostrKey == nil {
                // Try to get from NostrIdentityBridge association
-                peerNostrKey = NostrIdentityBridge.getNostrPublicKey(for: peer.noisePublicKey)
+                peerNostrKey = idBridge.getNostrPublicKey(for: peer.noisePublicKey)
            }
            
            // Add favorite
@@ -341,7 +348,7 @@ final class UnifiedPeerService: ObservableObject, TransportPeerEventsDelegate {
    // MARK: - Compatibility Methods (for easy migration)
    
    var allPeers: [BitchatPeer] { peers }
-    var connectedPeers: [PeerID] { Array(connectedPeerIDs) }
+    var connectedPeers: Set<PeerID> { connectedPeerIDs }
    var favoritePeers: Set<String> {
        Set(favorites.compactMap { getFingerprint(for: $0.peerID) })
    }
@@ -1,4 +1,6 @@
 import Foundation
+import BitLogger
+import BitFoundation

 // Gossip-based sync manager using on-demand GCS filters
 final class GossipSyncManager {
@@ -6,6 +8,56 @@ final class GossipSyncManager {
        func sendPacket(_ packet: BitchatPacket)
        func sendPacket(to peerID: PeerID, packet: BitchatPacket)
        func signPacketForBroadcast(_ packet: BitchatPacket) -> BitchatPacket
+        func getConnectedPeers() -> [PeerID]
+    }
+
+    private struct PacketStore {
+        private(set) var packets: [String: BitchatPacket] = [:]
+        private(set) var order: [String] = []
+
+        mutating func insert(idHex: String, packet: BitchatPacket, capacity: Int) {
+            guard capacity > 0 else { return }
+            if packets[idHex] != nil {
+                packets[idHex] = packet
+                return
+            }
+            packets[idHex] = packet
+            order.append(idHex)
+            while order.count > capacity {
+                let victim = order.removeFirst()
+                packets.removeValue(forKey: victim)
+            }
+        }
+
+        func allPackets(isFresh: (BitchatPacket) -> Bool) -> [BitchatPacket] {
+            order.compactMap { key in
+                guard let packet = packets[key], isFresh(packet) else { return nil }
+                return packet
+            }
+        }
+
+        mutating func remove(where shouldRemove: (BitchatPacket) -> Bool) {
+            var nextOrder: [String] = []
+            for key in order {
+                guard let packet = packets[key] else { continue }
+                if shouldRemove(packet) {
+                    packets.removeValue(forKey: key)
+                } else {
+                    nextOrder.append(key)
+                }
+            }
+            order = nextOrder
+        }
+
+        mutating func removeExpired(isFresh: (BitchatPacket) -> Bool) {
+            remove { !isFresh($0) }
+        }
+    }
+
+    private struct SyncSchedule {
+        let types: SyncTypeFlags
+        let interval: TimeInterval
+        var lastSent: Date
    }

    struct Config {
@@ -13,33 +65,57 @@ final class GossipSyncManager {
        var gcsMaxBytes: Int = 400           // filter size budget (128..1024)
        var gcsTargetFpr: Double = 0.01      // 1%
        var maxMessageAgeSeconds: TimeInterval = 900  // 15 min - discard older messages
+        var maintenanceIntervalSeconds: TimeInterval = 30.0
+        var stalePeerCleanupIntervalSeconds: TimeInterval = 60.0
+        var stalePeerTimeoutSeconds: TimeInterval = 60.0
+        var fragmentCapacity: Int = 600
+        var fileTransferCapacity: Int = 200
+        var fragmentSyncIntervalSeconds: TimeInterval = 30.0
+        var fileTransferSyncIntervalSeconds: TimeInterval = 60.0
+        var messageSyncIntervalSeconds: TimeInterval = 15.0
    }

    private let myPeerID: PeerID
    private let config: Config
+    private let requestSyncManager: RequestSyncManager
    weak var delegate: Delegate?

-    // Storage: broadcast messages (ordered by insert), and latest announce per sender
-    private var messages: [String: BitchatPacket] = [:] // idHex -> packet
-    private var messageOrder: [String] = []
-    private var latestAnnouncementByPeer: [String: (id: String, packet: BitchatPacket)] = [:]
+    // Storage: broadcast packets by type, and latest announce per sender
+    private var messages = PacketStore()
+    private var fragments = PacketStore()
+    private var fileTransfers = PacketStore()
+    private var latestAnnouncementByPeer: [PeerID: (id: String, packet: BitchatPacket)] = [:]

    // Timer
    private var periodicTimer: DispatchSourceTimer?
    private let queue = DispatchQueue(label: "mesh.sync", qos: .utility)
+    private var lastStalePeerCleanup: Date = .distantPast
+    private var syncSchedules: [SyncSchedule] = []

-    init(myPeerID: PeerID, config: Config = Config()) {
+    init(myPeerID: PeerID, config: Config = Config(), requestSyncManager: RequestSyncManager) {
        self.myPeerID = myPeerID
        self.config = config
+        self.requestSyncManager = requestSyncManager
+        var schedules: [SyncSchedule] = []
+        if config.seenCapacity > 0 && config.messageSyncIntervalSeconds > 0 {
+            schedules.append(SyncSchedule(types: .publicMessages, interval: config.messageSyncIntervalSeconds, lastSent: .distantPast))
+        }
+        if config.fragmentCapacity > 0 && config.fragmentSyncIntervalSeconds > 0 {
+            schedules.append(SyncSchedule(types: .fragment, interval: config.fragmentSyncIntervalSeconds, lastSent: .distantPast))
+        }
+        if config.fileTransferCapacity > 0 && config.fileTransferSyncIntervalSeconds > 0 {
+            schedules.append(SyncSchedule(types: .fileTransfer, interval: config.fileTransferSyncIntervalSeconds, lastSent: .distantPast))
+        }
+        syncSchedules = schedules
    }

    func start() {
        stop()
        let timer = DispatchSource.makeTimerSource(queue: queue)
-        timer.schedule(deadline: .now() + 30.0, repeating: 30.0, leeway: .seconds(1))
+        let interval = max(0.1, config.maintenanceIntervalSeconds)
+        timer.schedule(deadline: .now() + interval, repeating: interval, leeway: .seconds(1))
        timer.setEventHandler { [weak self] in
-            self?.cleanupExpiredMessages()
-            self?.sendRequestSync()
+            self?.performPeriodicMaintenance()
        }
        timer.resume()
        periodicTimer = timer
@@ -51,7 +127,18 @@ final class GossipSyncManager {

    func scheduleInitialSyncToPeer(_ peerID: PeerID, delaySeconds: TimeInterval = 5.0) {
        queue.asyncAfter(deadline: .now() + delaySeconds) { [weak self] in
-            self?.sendRequestSync(to: peerID)
+            guard let self = self else { return }
+            self.sendRequestSync(to: peerID, types: .publicMessages)
+            if self.config.fragmentCapacity > 0 && self.config.fragmentSyncIntervalSeconds > 0 {
+                self.queue.asyncAfter(deadline: .now() + 0.5) { [weak self] in
+                    self?.sendRequestSync(to: peerID, types: .fragment)
+                }
+            }
+            if self.config.fileTransferCapacity > 0 && self.config.fileTransferSyncIntervalSeconds > 0 {
+                self.queue.asyncAfter(deadline: .now() + 1.0) { [weak self] in
+                    self?.sendRequestSync(to: peerID, types: .fileTransfer)
+                }
+            }
        }
    }

@@ -73,40 +160,68 @@ final class GossipSyncManager {
        return packet.timestamp >= cutoffMs
    }

+    private func isAnnouncementFresh(_ packet: BitchatPacket) -> Bool {
+        guard config.stalePeerTimeoutSeconds > 0 else { return true }
+        let nowMs = UInt64(Date().timeIntervalSince1970 * 1000)
+        let timeoutMs = UInt64(config.stalePeerTimeoutSeconds * 1000)
+        guard nowMs >= timeoutMs else { return true }
+        let cutoffMs = nowMs - timeoutMs
+        return packet.timestamp >= cutoffMs
+    }
+
    private func _onPublicPacketSeen(_ packet: BitchatPacket) {
-        let mt = MessageType(rawValue: packet.type)
+        guard let messageType = MessageType(rawValue: packet.type) else { return }
        let isBroadcastRecipient: Bool = {
            guard let r = packet.recipientID else { return true }
            return r.count == 8 && r.allSatisfy { $0 == 0xFF }
        }()
-        let isBroadcastMessage = (mt == .message && isBroadcastRecipient)
-        let isAnnounce = (mt == .announce)
-        guard isBroadcastMessage || isAnnounce else { return }

-        // Reject expired packets to prevent ghost peers and old messages
-        guard isPacketFresh(packet) else { return }
-
-        let idHex = PacketIdUtil.computeId(packet).hexEncodedString()
-
-        if isBroadcastMessage {
-            if messages[idHex] == nil {
-                messages[idHex] = packet
-                messageOrder.append(idHex)
-                // Enforce capacity
-                let cap = max(1, config.seenCapacity)
-                while messageOrder.count > cap {
-                    let victim = messageOrder.removeFirst()
-                    messages.removeValue(forKey: victim)
-                }
+        switch messageType {
+        case .announce:
+            guard isPacketFresh(packet) else { return }
+            guard isAnnouncementFresh(packet) else {
+                let sender = PeerID(hexData: packet.senderID)
+                removeState(for: sender)
+                return
            }
-        } else if isAnnounce {
-            let sender = packet.senderID.hexEncodedString()
+            let idHex = PacketIdUtil.computeId(packet).hexEncodedString()
+            let sender = PeerID(hexData: packet.senderID)
            latestAnnouncementByPeer[sender] = (id: idHex, packet: packet)
+        case .message:
+            guard isBroadcastRecipient else { return }
+            guard isPacketFresh(packet) else { return }
+            let idHex = PacketIdUtil.computeId(packet).hexEncodedString()
+            messages.insert(idHex: idHex, packet: packet, capacity: max(1, config.seenCapacity))
+        case .fragment:
+            guard isBroadcastRecipient else { return }
+            guard isPacketFresh(packet) else { return }
+            let idHex = PacketIdUtil.computeId(packet).hexEncodedString()
+            fragments.insert(idHex: idHex, packet: packet, capacity: max(1, config.fragmentCapacity))
+        case .fileTransfer:
+            guard isBroadcastRecipient else { return }
+            guard isPacketFresh(packet) else { return }
+            let idHex = PacketIdUtil.computeId(packet).hexEncodedString()
+            fileTransfers.insert(idHex: idHex, packet: packet, capacity: max(1, config.fileTransferCapacity))
+        default:
+            break
        }
    }

-    private func sendRequestSync() {
-        let payload = buildGcsPayload()
+    private func sendPeriodicSync(for types: SyncTypeFlags) {
+        // Unicast sync to connected peers to allow RSR attribution
+        if let connectedPeers = delegate?.getConnectedPeers(), !connectedPeers.isEmpty {
+            SecureLogger.debug("Sending periodic sync to \(connectedPeers.count) connected peers", category: .sync)
+            for peerID in connectedPeers {
+                sendRequestSync(to: peerID, types: types)
+            }
+        } else {
+            // Fallback to broadcast (discovery phase)
+            sendRequestSync(for: types)
+        }
+    }
+
+    private func sendRequestSync(for types: SyncTypeFlags) {
+        let payload = buildGcsPayload(for: types)
        let pkt = BitchatPacket(
            type: MessageType.requestSync.rawValue,
            senderID: Data(hexString: myPeerID.id) ?? Data(),
@@ -120,8 +235,11 @@ final class GossipSyncManager {
        delegate?.sendPacket(signed)
    }

-    private func sendRequestSync(to peerID: PeerID) {
-        let payload = buildGcsPayload()
+    private func sendRequestSync(to peerID: PeerID, types: SyncTypeFlags) {
+        // Register the request for RSR validation
+        requestSyncManager.registerRequest(to: peerID)
+        
+        let payload = buildGcsPayload(for: types)
        var recipient = Data()
        var temp = peerID.id
        while temp.count >= 2 && recipient.count < 8 {
@@ -149,6 +267,7 @@ final class GossipSyncManager {
    }

    private func _handleRequestSync(from peerID: PeerID, request: RequestSyncPacket) {
+        let requestedTypes = (request.types ?? .publicMessages)
        // Decode GCS into sorted set and prepare membership checker
        let sorted = GCSFilter.decodeToSortedSet(p: request.p, m: request.m, data: request.data)
        func mightContain(_ id: Data) -> Bool {
@@ -156,60 +275,104 @@ final class GossipSyncManager {
            return GCSFilter.contains(sortedValues: sorted, candidate: bucket)
        }

-        // 1) Announcements: send latest per peer if requester lacks them (and not expired)
-        for (_, pair) in latestAnnouncementByPeer {
-            let (idHex, pkt) = pair
-            guard isPacketFresh(pkt) else { continue }
-            let idBytes = Data(hexString: idHex) ?? Data()
-            if !mightContain(idBytes) {
-                var toSend = pkt
-                toSend.ttl = 0
-                delegate?.sendPacket(to: peerID, packet: toSend)
+        if requestedTypes.contains(.announce) {
+            for (_, pair) in latestAnnouncementByPeer {
+                let (idHex, pkt) = pair
+                guard isPacketFresh(pkt) else { continue }
+                let idBytes = Data(hexString: idHex) ?? Data()
+                if !mightContain(idBytes) {
+                    var toSend = pkt
+                    toSend.ttl = 0
+                    toSend.isRSR = true // Mark as solicited response
+                    delegate?.sendPacket(to: peerID, packet: toSend)
+                }
            }
        }

-        // 2) Broadcast messages: send all missing (and not expired)
-        let toSendMsgs = messageOrder.compactMap { messages[$0] }
-        for pkt in toSendMsgs {
-            guard isPacketFresh(pkt) else { continue }
-            let idBytes = PacketIdUtil.computeId(pkt)
-            if !mightContain(idBytes) {
-                var toSend = pkt
-                toSend.ttl = 0
-                delegate?.sendPacket(to: peerID, packet: toSend)
+        if requestedTypes.contains(.message) {
+            let toSendMsgs = messages.allPackets(isFresh: isPacketFresh)
+            for pkt in toSendMsgs {
+                let idBytes = PacketIdUtil.computeId(pkt)
+                if !mightContain(idBytes) {
+                    var toSend = pkt
+                    toSend.ttl = 0
+                    toSend.isRSR = true // Mark as solicited response
+                    delegate?.sendPacket(to: peerID, packet: toSend)
+                }
+            }
+        }
+
+        if requestedTypes.contains(.fragment) {
+            let frags = fragments.allPackets(isFresh: isPacketFresh)
+            for pkt in frags {
+                let idBytes = PacketIdUtil.computeId(pkt)
+                if !mightContain(idBytes) {
+                    var toSend = pkt
+                    toSend.ttl = 0
+                    toSend.isRSR = true // Mark as solicited response
+                    delegate?.sendPacket(to: peerID, packet: toSend)
+                }
+            }
+        }
+
+        if requestedTypes.contains(.fileTransfer) {
+            let files = fileTransfers.allPackets(isFresh: isPacketFresh)
+            for pkt in files {
+                let idBytes = PacketIdUtil.computeId(pkt)
+                if !mightContain(idBytes) {
+                    var toSend = pkt
+                    toSend.ttl = 0
+                    toSend.isRSR = true // Mark as solicited response
+                    delegate?.sendPacket(to: peerID, packet: toSend)
+                }
            }
        }
    }

    // Build REQUEST_SYNC payload using current candidates and GCS params
-    private func buildGcsPayload() -> Data {
-        // Collect candidates: latest announce per peer + broadcast messages (only fresh)
+    private func buildGcsPayload(for types: SyncTypeFlags) -> Data {
        var candidates: [BitchatPacket] = []
-        candidates.reserveCapacity(latestAnnouncementByPeer.count + messageOrder.count)
-        for (_, pair) in latestAnnouncementByPeer {
-            if isPacketFresh(pair.packet) {
+        if types.contains(.announce) {
+            for (_, pair) in latestAnnouncementByPeer where isPacketFresh(pair.packet) {
                candidates.append(pair.packet)
            }
        }
-        for id in messageOrder {
-            if let p = messages[id], isPacketFresh(p) {
-                candidates.append(p)
-            }
+        if types.contains(.message) {
+            candidates.append(contentsOf: messages.allPackets(isFresh: isPacketFresh))
        }
+        if types.contains(.fragment) {
+            candidates.append(contentsOf: fragments.allPackets(isFresh: isPacketFresh))
+        }
+        if types.contains(.fileTransfer) {
+            candidates.append(contentsOf: fileTransfers.allPackets(isFresh: isPacketFresh))
+        }
+        if candidates.isEmpty {
+            let p = GCSFilter.deriveP(targetFpr: config.gcsTargetFpr)
+            let req = RequestSyncPacket(p: p, m: 1, data: Data(), types: types)
+            return req.encode()
+        }
+
        // Sort by timestamp desc
        candidates.sort { $0.timestamp > $1.timestamp }

        let p = GCSFilter.deriveP(targetFpr: config.gcsTargetFpr)
        let nMax = GCSFilter.estimateMaxElements(sizeBytes: config.gcsMaxBytes, p: p)
-        let cap = max(1, config.seenCapacity)
+        let cap: Int
+        if types == .fragment {
+            cap = max(1, config.fragmentCapacity)
+        } else if types == .fileTransfer {
+            cap = max(1, config.fileTransferCapacity)
+        } else {
+            cap = max(1, config.seenCapacity)
+        }
        let takeN = min(candidates.count, min(nMax, cap))
        if takeN <= 0 {
-            let req = RequestSyncPacket(p: p, m: 1, data: Data())
+            let req = RequestSyncPacket(p: p, m: 1, data: Data(), types: types)
            return req.encode()
        }
        let ids: [Data] = candidates.prefix(takeN).map { PacketIdUtil.computeId($0) }
        let params = GCSFilter.buildFilter(ids: ids, maxBytes: config.gcsMaxBytes, targetFpr: config.gcsTargetFpr)
-        let req = RequestSyncPacket(p: params.p, m: params.m, data: params.data)
+        let req = RequestSyncPacket(p: params.p, m: params.m, data: params.data, types: types)
        return req.encode()
    }

@@ -220,37 +383,80 @@ final class GossipSyncManager {
            isPacketFresh(pair.packet)
        }

-        // Remove expired messages
-        let expiredMessageIds = messages.compactMap { id, pkt in
-            isPacketFresh(pkt) ? nil : id
+        messages.removeExpired(isFresh: isPacketFresh)
+        fragments.removeExpired(isFresh: isPacketFresh)
+        fileTransfers.removeExpired(isFresh: isPacketFresh)
+    }
+
+    private func performPeriodicMaintenance(now: Date = Date()) {
+        cleanupExpiredMessages()
+        cleanupStaleAnnouncementsIfNeeded(now: now)
+        requestSyncManager.cleanup() // Cleanup expired sync requests
+        
+        for index in syncSchedules.indices {
+            guard syncSchedules[index].interval > 0 else { continue }
+            if syncSchedules[index].lastSent == .distantPast || now.timeIntervalSince(syncSchedules[index].lastSent) >= syncSchedules[index].interval {
+                syncSchedules[index].lastSent = now
+                sendPeriodicSync(for: syncSchedules[index].types)
+            }
        }
-        for id in expiredMessageIds {
-            messages.removeValue(forKey: id)
-            messageOrder.removeAll { $0 == id }
+    }
+
+    private func cleanupStaleAnnouncementsIfNeeded(now: Date) {
+        guard now.timeIntervalSince(lastStalePeerCleanup) >= config.stalePeerCleanupIntervalSeconds else {
+            return
+        }
+        lastStalePeerCleanup = now
+        cleanupStaleAnnouncements(now: now)
+    }
+
+    private func cleanupStaleAnnouncements(now: Date) {
+        let timeoutMs = UInt64(config.stalePeerTimeoutSeconds * 1000)
+        let nowMs = UInt64(now.timeIntervalSince1970 * 1000)
+        guard nowMs >= timeoutMs else { return }
+        let cutoff = nowMs - timeoutMs
+        let stalePeerIDs = latestAnnouncementByPeer.compactMap { peerID, pair in
+            pair.packet.timestamp < cutoff ? peerID : nil
+        }
+        guard !stalePeerIDs.isEmpty else { return }
+        for peerKey in stalePeerIDs {
+            removeState(for: peerKey)
        }
    }

    // Explicit removal hook for LEAVE/stale peer
    func removeAnnouncementForPeer(_ peerID: PeerID) {
        queue.async { [weak self] in
-            self?._removeAnnouncementForPeer(peerID)
+            self?.removeState(for: peerID)
        }
    }

-    private func _removeAnnouncementForPeer(_ peerID: PeerID) {
-        let normalizedPeerID = peerID.id.lowercased()
-        _ = latestAnnouncementByPeer.removeValue(forKey: normalizedPeerID)
+    private func removeState(for peerID: PeerID) {
+        _ = latestAnnouncementByPeer.removeValue(forKey: peerID)
+        messages.remove { PeerID(hexData: $0.senderID) == peerID }
+        fragments.remove { PeerID(hexData: $0.senderID) == peerID }
+        fileTransfers.remove { PeerID(hexData: $0.senderID) == peerID }
+    }
+}

-        // Remove messages from this peer
-        // Collect IDs to remove first to avoid concurrent modification
-        let messageIdsToRemove = messages.compactMap { (id, message) -> String? in
-            message.senderID.hexEncodedString().lowercased() == normalizedPeerID ? id : nil
+#if DEBUG
+extension GossipSyncManager {
+    func _performMaintenanceSynchronously(now: Date = Date()) {
+        queue.sync {
+            performPeriodicMaintenance(now: now)
        }
-        
-        // Remove messages and update messageOrder
-        for id in messageIdsToRemove {
-            messages.removeValue(forKey: id)
-            messageOrder.removeAll { $0 == id }
+    }
+
+    func _hasAnnouncement(for peerID: PeerID) -> Bool {
+        queue.sync {
+            latestAnnouncementByPeer[peerID] != nil
+        }
+    }
+
+    func _messageCount(for peerID: PeerID) -> Int {
+        queue.sync {
+            messages.allPackets { _ in true }.filter { PeerID(hexData: $0.senderID) == peerID }.count
        }
    }
 }
+#endif
@@ -0,0 +1,86 @@
+//
+// RequestSyncManager.swift
+// bitchat
+//
+// This is free and unencumbered software released into the public domain.
+// For more information, see <https://unlicense.org>
+//
+
+import Foundation
+import BitLogger
+import BitFoundation
+
+/// Manages outgoing sync requests and validates incoming responses.
+///
+/// Allows attributing RSR (Request-Sync Response) packets to specific peers
+/// that we have actively requested sync from.
+final class RequestSyncManager {
+    
+    private let queue = DispatchQueue(label: "request.sync.manager", attributes: .concurrent)
+    private var pendingRequests: [PeerID: TimeInterval] = [:]
+    private let responseWindow: TimeInterval
+    private let now: () -> TimeInterval
+    
+    init(
+        responseWindow: TimeInterval = 30.0,
+        now: @escaping () -> TimeInterval = { Date().timeIntervalSince1970 }
+    ) {
+        self.responseWindow = responseWindow
+        self.now = now
+    }
+    
+    /// Register that we are sending a sync request to a peer.
+    /// - Parameter peerID: The peer we are requesting sync from
+    func registerRequest(to peerID: PeerID) {
+        let now = self.now()
+        queue.async(flags: .barrier) {
+            SecureLogger.debug("Registering sync request to \(peerID.id.prefix(8))…", category: .sync)
+            self.pendingRequests[peerID] = now
+        }
+    }
+    
+    /// Check if a packet from a peer is a valid response to a sync request.
+    ///
+    /// - Parameters:
+    ///   - peerID: The sender of the packet
+    ///   - isRSR: Whether the packet is marked as a Request-Sync Response
+    /// - Returns: true if we have a pending request for this peer and the window is open
+    func isValidResponse(from peerID: PeerID, isRSR: Bool) -> Bool {
+        guard isRSR else { return false }
+        
+        return queue.sync {
+            guard let requestTime = pendingRequests[peerID] else {
+                SecureLogger.warning("Received unsolicited RSR packet from \(peerID.id.prefix(8))…", category: .security)
+                return false
+            }
+            
+            let now = self.now()
+            if now - requestTime > responseWindow {
+                SecureLogger.warning("Received RSR packet from \(peerID.id.prefix(8))… outside of response window", category: .security)
+                // We don't remove here because we might receive multiple packets for one request
+                return false
+            }
+            
+            return true
+        }
+    }
+    
+    /// Periodic cleanup of expired requests
+    func cleanup() {
+        let now = self.now()
+        queue.async(flags: .barrier) {
+            let originalCount = self.pendingRequests.count
+            self.pendingRequests = self.pendingRequests.filter { _, timestamp in
+                now - timestamp <= self.responseWindow
+            }
+            let removed = originalCount - self.pendingRequests.count
+            if removed > 0 {
+                SecureLogger.debug("Cleaned up \(removed) expired sync requests", category: .sync)
+            }
+        }
+    }
+
+    var debugPendingRequestCount: Int {
+        queue.sync { pendingRequests.count }
+    }
+}
@@ -0,0 +1,104 @@
+import Foundation
+
+/// Bitfield describing which message types are covered by a REQUEST_SYNC round.
+/// Matches the Android mapping (bit index -> message type).
+struct SyncTypeFlags: OptionSet {
+    let rawValue: UInt64
+
+    init(rawValue: UInt64) {
+        self.rawValue = rawValue & 0x00FF_FFFF_FFFF_FFFF // Trim to max 8 bytes
+    }
+
+    private static func bitIndex(for type: MessageType) -> Int? {
+        switch type {
+        case .announce: return 0
+        case .message: return 1
+        case .leave: return 2
+        case .noiseHandshake: return 3
+        case .noiseEncrypted: return 4
+        case .fragment: return 5
+        case .requestSync: return 6
+        case .fileTransfer: return 7
+        }
+    }
+
+    private static func type(forBit index: Int) -> MessageType? {
+        switch index {
+        case 0: return .announce
+        case 1: return .message
+        case 2: return .leave
+        case 3: return .noiseHandshake
+        case 4: return .noiseEncrypted
+        case 5: return .fragment
+        case 6: return .requestSync
+        case 7: return .fileTransfer
+        default:
+            return nil
+        }
+    }
+
+    static let announce = SyncTypeFlags(messageTypes: [.announce])
+    static let message = SyncTypeFlags(messageTypes: [.message])
+    static let fragment = SyncTypeFlags(messageTypes: [.fragment])
+    static let fileTransfer = SyncTypeFlags(messageTypes: [.fileTransfer])
+
+    static let publicMessages = SyncTypeFlags(messageTypes: [.announce, .message])
+
+    init(messageTypes: [MessageType]) {
+        var raw: UInt64 = 0
+        for type in messageTypes {
+            guard let bit = SyncTypeFlags.bitIndex(for: type) else { continue }
+            raw |= (1 << UInt64(bit))
+        }
+        self.init(rawValue: raw)
+    }
+
+    func contains(_ type: MessageType) -> Bool {
+        guard let bit = SyncTypeFlags.bitIndex(for: type) else { return false }
+        return contains(SyncTypeFlags(rawValue: 1 << UInt64(bit)))
+    }
+
+    func union(_ other: SyncTypeFlags) -> SyncTypeFlags {
+        SyncTypeFlags(rawValue: rawValue | other.rawValue)
+    }
+
+    func intersection(_ other: SyncTypeFlags) -> SyncTypeFlags {
+        SyncTypeFlags(rawValue: rawValue & other.rawValue)
+    }
+
+    func toMessageTypes() -> [MessageType] {
+        guard rawValue != 0 else { return [] }
+        var types: [MessageType] = []
+        for bit in 0..<64 {
+            guard (rawValue & (1 << UInt64(bit))) != 0 else { continue }
+            if let type = SyncTypeFlags.type(forBit: bit) {
+                types.append(type)
+            }
+        }
+        return types
+    }
+
+    func toData() -> Data? {
+        guard rawValue != 0 else { return nil }
+        var value = rawValue
+        var bytes: [UInt8] = []
+        while value > 0 && bytes.count < 8 {
+            bytes.append(UInt8(value & 0xFF))
+            value >>= 8
+        }
+        while let last = bytes.last, last == 0 {
+            bytes.removeLast()
+        }
+        guard !bytes.isEmpty, bytes.count <= 8 else { return nil }
+        return Data(bytes)
+    }
+
+    static func decode(_ data: Data) -> SyncTypeFlags? {
+        guard (1...8).contains(data.count) else { return nil }
+        var raw: UInt64 = 0
+        for (index, byte) in data.enumerated() {
+            raw |= UInt64(byte) << UInt64(index * 8)
+        }
+        return SyncTypeFlags(rawValue: raw)
+    }
+}
@@ -61,15 +61,13 @@ struct CompressionUtil {
        // 1. Data is too small
        // 2. Data appears to be already compressed (high entropy)
        guard data.count >= compressionThreshold else { return false }
-        
-        // Simple entropy check - count unique bytes
-        var byteFrequency = [UInt8: Int]()
-        for byte in data {
-            byteFrequency[byte, default: 0] += 1
-        }
-        
-        // If we have very high byte diversity, data is likely already compressed
-        let uniqueByteRatio = Double(byteFrequency.count) / Double(min(data.count, 256))
+
+        // Quick uniqueness check — a high diversity of bytes usually means the
+        // payload is already compressed. We only need to know how many unique
+        // values exist rather than keeping full frequency counts.
+        let uniqueByteCount = Set(data).count
+        let sampleSize = min(data.count, 256)
+        let uniqueByteRatio = Double(uniqueByteCount) / Double(sampleSize)
        return uniqueByteRatio < 0.9 // Compress if less than 90% unique bytes
    }
 }
@@ -1,22 +0,0 @@
-//
-//  Data+SHA256.swift
-//  bitchat
-//
-//  Created by Islam on 26/09/2025.
-//
-
-import struct Foundation.Data
-import struct CryptoKit.SHA256
-
-extension Data {
-    /// Returns the hex representation of SHA256 hash
-    func sha256Fingerprint() -> String {
-        // Implementation matches existing fingerprint generation in NoiseEncryptionService
-        sha256Hash().hexEncodedString()
-    }
-    
-    /// Returns the SHA256 hash wrapped in Data
-    func sha256Hash() -> Data {
-        Data(SHA256.hash(data: self))
-    }
-}
@@ -0,0 +1,25 @@
+import Foundation
+
+/// Centralized thresholds for Bluetooth file transfers to keep payload sizes sane on constrained radios.
+enum FileTransferLimits {
+    /// Absolute ceiling enforced for any file payload (voice, image, other).
+    static let maxPayloadBytes: Int = 1 * 1024 * 1024 // 1 MiB
+    /// Voice notes stay small for low-latency relays.
+    static let maxVoiceNoteBytes: Int = 512 * 1024 // 512 KiB
+    /// Compressed images after downscaling should comfortably fit under this budget.
+    static let maxImageBytes: Int = 512 * 1024 // 512 KiB
+    /// Worst-case size once TLV metadata and binary packet framing are included for the largest payloads.
+    static let maxFramedFileBytes: Int = {
+        let maxMetadataBytes = Int(UInt16.max) * 2 // fileName + mimeType TLVs
+        let tlvEnvelopeOverhead = 18 + maxMetadataBytes // TLV tags + lengths + metadata bytes
+        let binaryEnvelopeOverhead = BinaryProtocol.v2HeaderSize
+            + BinaryProtocol.senderIDSize
+            + BinaryProtocol.recipientIDSize
+            + BinaryProtocol.signatureSize
+        return maxPayloadBytes + tlvEnvelopeOverhead + binaryEnvelopeOverhead
+    }()
+
+    static func isValidPayload(_ size: Int) -> Bool {
+        size <= maxPayloadBytes
+    }
+}
@@ -1,4 +1,5 @@
 import Foundation
+import BitLogger

 /// Comprehensive input validation for BitChat protocol
 /// Prevents injection attacks, buffer overflows, and malformed data
@@ -16,29 +17,26 @@ struct InputValidator {
    // MARK: - String Content Validation
    
    /// Validates and sanitizes user-provided strings used in UI
+    ///
+    /// Rejects strings containing control characters to prevent potential security issues
+    /// and UI rendering problems. This strict approach ensures data integrity at input time.
    static func validateUserString(_ string: String, maxLength: Int) -> String? {
-        // Check empty
-        guard !string.isEmpty else { return nil }
+        guard let trimmed = string.trimmedOrNilIfEmpty, trimmed.count <= maxLength else { return nil }

-        // Trim whitespace
-        let trimmed = string.trimmingCharacters(in: .whitespacesAndNewlines)
-        guard !trimmed.isEmpty else { return nil }
-
-        // Check length
-        guard trimmed.count <= maxLength else { return nil }
-
-        // Remove control characters
+        // Reject control characters outright instead of rewriting the string.
+        // This prevents injection attacks and ensures consistent UI rendering.
        let controlChars = CharacterSet.controlCharacters
-        let cleaned = trimmed.components(separatedBy: controlChars).joined()
-        
-        // Ensure valid UTF-8 (should already be, but double-check)
-        guard cleaned.data(using: .utf8) != nil else { return nil }
-        
-        // Prevent zero-width characters and other invisible unicode
-        let invisibleChars = CharacterSet(charactersIn: "\u{200B}\u{200C}\u{200D}\u{FEFF}")
-        let visible = cleaned.components(separatedBy: invisibleChars).joined()
-        
-        return visible.isEmpty ? nil : visible
+        if !trimmed.unicodeScalars.allSatisfy({ !controlChars.contains($0) }) {
+            // Log rejection for monitoring, without exposing actual content for privacy
+            let controlCharCount = trimmed.unicodeScalars.filter { controlChars.contains($0) }.count
+            SecureLogger.debug(
+                "Input validation rejected string (length: \(trimmed.count), control chars: \(controlCharCount))",
+                category: .security
+            )
+            return nil
+        }
+
+        return trimmed
    }
    
    /// Validates nickname
@@ -52,11 +50,13 @@ struct InputValidator {
    // MessageType/NoisePayloadType enums; keeping validator free of stale lists.

    /// Validates timestamp is reasonable (not too far in past or future)
+    /// BCH-01-011: Reduced from ±1 hour to ±5 minutes to limit replay attack window
    static func validateTimestamp(_ timestamp: Date) -> Bool {
        let now = Date()
-        let oneHourAgo = now.addingTimeInterval(-3600)
-        let oneHourFromNow = now.addingTimeInterval(3600)
-        return timestamp >= oneHourAgo && timestamp <= oneHourFromNow
+        // 5 minutes = 300 seconds (industry standard for replay protection)
+        let fiveMinutesAgo = now.addingTimeInterval(-300)
+        let fiveMinutesFromNow = now.addingTimeInterval(300)
+        return timestamp >= fiveMinutesAgo && timestamp <= fiveMinutesFromNow
    }

 }
@@ -2,66 +2,112 @@ import Foundation

 // MARK: - Message Deduplicator (shared)

+/// Thread-safe deduplicator with LRU eviction and time-based expiry.
+/// Used for both message ID deduplication (network layer) and content key deduplication (UI layer).
 final class MessageDeduplicator {
-    private struct Entry {
-        let messageID: String
+    private struct Entry: Equatable {
+        let id: String
        let timestamp: Date
    }

    private var entries: [Entry] = []
    private var head: Int = 0
-    private var lookup = Set<String>()
+    private var lookup: [String: Date] = [:]  // id -> timestamp for O(1) lookup
    private let lock = NSLock()
-    private let maxAge: TimeInterval = TransportConfig.messageDedupMaxAgeSeconds  // 5 minutes
-    private let maxCount = TransportConfig.messageDedupMaxCount
+    private let maxAge: TimeInterval
+    private let maxCount: Int

-    /// Check if message is duplicate and add if not
-    func isDuplicate(_ messageID: String) -> Bool {
+    /// Initialize with default config from TransportConfig
+    convenience init() {
+        self.init(
+            maxAge: TransportConfig.messageDedupMaxAgeSeconds,
+            maxCount: TransportConfig.messageDedupMaxCount
+        )
+    }
+
+    /// Initialize with custom config for content deduplication
+    init(maxAge: TimeInterval, maxCount: Int) {
+        self.maxAge = maxAge
+        self.maxCount = maxCount
+    }
+
+    /// Check if message is duplicate and add if not.
+    /// - Parameter id: The message identifier to check.
+    /// - Returns: `true` if the message was already seen, `false` otherwise.
+    func isDuplicate(_ id: String) -> Bool {
        lock.lock()
        defer { lock.unlock() }

-        cleanupOldEntries()
+        let now = Date()
+        cleanupOldEntries(before: now.addingTimeInterval(-maxAge))

-        if lookup.contains(messageID) {
+        if lookup[id] != nil {
            return true
        }

-        entries.append(Entry(messageID: messageID, timestamp: Date()))
-        lookup.insert(messageID)
-
-        // Soft-cap and advance head by a chunk to avoid O(n) shifting
-        if (entries.count - head) > maxCount {
-            let removeCount = min(100, entries.count - head)
-            for i in head..<(head + removeCount) {
-                lookup.remove(entries[i].messageID)
-            }
-            head += removeCount
-            // Periodically compact to reclaim memory
-            if head > entries.count / 2 {
-                entries.removeFirst(head)
-                head = 0
-            }
-        }
+        entries.append(Entry(id: id, timestamp: now))
+        lookup[id] = now
+        trimIfNeeded()

        return false
    }

-    /// Add an ID without checking (for announce-back tracking)
-    func markProcessed(_ messageID: String) {
+    /// Record an ID with a specific timestamp (for content key tracking)
+    func record(_ id: String, timestamp: Date) {
        lock.lock()
        defer { lock.unlock() }

-        if !lookup.contains(messageID) {
-            entries.append(Entry(messageID: messageID, timestamp: Date()))
-            lookup.insert(messageID)
+        if lookup[id] == nil {
+            entries.append(Entry(id: id, timestamp: timestamp))
+        }
+        lookup[id] = timestamp
+        trimIfNeeded()
+    }
+
+    /// Add an ID without checking (for announce-back tracking)
+    func markProcessed(_ id: String) {
+        lock.lock()
+        defer { lock.unlock() }
+
+        if lookup[id] == nil {
+            let now = Date()
+            entries.append(Entry(id: id, timestamp: now))
+            lookup[id] = now
        }
    }

    /// Check if ID exists without adding
-    func contains(_ messageID: String) -> Bool {
+    func contains(_ id: String) -> Bool {
        lock.lock()
        defer { lock.unlock() }
-        return lookup.contains(messageID)
+        return lookup[id] != nil
+    }
+
+    /// Get timestamp for an ID (for content deduplication time-window checks)
+    func timestampFor(_ id: String) -> Date? {
+        lock.lock()
+        defer { lock.unlock() }
+        return lookup[id]
+    }
+
+    private func trimIfNeeded() {
+        let activeCount = entries.count - head
+        guard activeCount > maxCount else { return }
+
+        // Remove down to 75% of maxCount for better amortization
+        let targetCount = (maxCount * 3) / 4
+        let removeCount = activeCount - targetCount
+
+        for i in head..<(head + removeCount) {
+            lookup.removeValue(forKey: entries[i].id)
+        }
+        head += removeCount
+
+        // Compact when head exceeds half the array to reclaim memory
+        if head > entries.count / 2 {
+            entries.removeFirst(head)
+            head = 0
+        }
    }

    /// Clear all entries
@@ -74,24 +120,25 @@ final class MessageDeduplicator {
        lookup.removeAll()
    }

-    /// Periodic cleanup
+    /// Periodic cleanup of expired entries and memory optimization.
    func cleanup() {
        lock.lock()
        defer { lock.unlock() }

-        cleanupOldEntries()
+        cleanupOldEntries(before: Date().addingTimeInterval(-maxAge))

-        if entries.capacity > maxCount * 2 {
+        // Shrink capacity if significantly oversized
+        if entries.capacity > maxCount * 2 && entries.count < maxCount {
            entries.reserveCapacity(maxCount)
        }
    }

-    private func cleanupOldEntries() {
-        let cutoff = Date().addingTimeInterval(-maxAge)
+    private func cleanupOldEntries(before cutoff: Date) {
        while head < entries.count, entries[head].timestamp < cutoff {
-            lookup.remove(entries[head].messageID)
+            lookup.removeValue(forKey: entries[head].id)
            head += 1
        }
+        // Compact when head exceeds half the array
        if head > 0 && head > entries.count / 2 {
            entries.removeFirst(head)
            head = 0
@@ -1,4 +1,5 @@
 import Foundation
+import BitFoundation

 /// Resolves a stable display name for peers, adding a short suffix when collisions exist.
 struct PeerDisplayNameResolver {
@@ -0,0 +1,44 @@
+//
+// SystemSettings.swift
+// bitchat
+//
+// This is free and unencumbered software released into the public domain.
+// For more information, see <https://unlicense.org>
+//
+
+#if os(iOS)
+import UIKit
+#elseif os(macOS)
+import AppKit
+#endif
+
+enum SystemSettings {
+    case bluetooth
+    case location
+    case microphone
+
+    #if os(macOS)
+    private static let baseURL = "x-apple.systempreferences:com.apple.preference.security"
+
+    private var macPrivacyAnchor: String {
+        switch self {
+        case .bluetooth: "Privacy_Bluetooth"
+        case .location: "Privacy_LocationServices"
+        case .microphone: "Privacy_Microphone"
+        }
+    }
+    #endif
+
+    func open() {
+        #if os(iOS)
+        if let url = URL(string: UIApplication.openSettingsURLString) {
+            UIApplication.shared.open(url)
+        }
+        #elseif os(macOS)
+        let urlString = "\(Self.baseURL)?\(macPrivacyAnchor)"
+        if let url = URL(string: urlString) {
+            NSWorkspace.shared.open(url)
+        }
+        #endif
+    }
+}
--- a/Show More
+++ b/Show More