Localize the last hardcoded UI strings; wire up two dead translations (#1656)

* Add 26 code-referenced keys to the catalog + a test that closes the gap

LocalizationCoverageTests validated the catalog but never the code: a
String(localized:) whose key is missing from every catalog compiles
fine and silently ships its English defaultValue to all 29 non-source
locales. That blind spot let 26 keys go untranslated while CI stayed
green: the entire notices/board composer (10), the private-media
encryption warnings and delivery-failure reasons (9), both
courier-header strings, two delivery states, two media failure
reasons, and the [? people] channel row.

- All 26 keys added with full 30-locale coverage.
- New everyCodeReferencedKeyExistsInACatalog scans the source for
  literal String(localized:) keys and fails on any key absent from
  both catalogs. (The audit's original count of 17 was itself an
  undercount — its scan missed multi-line String( localized: calls;
  the test's regex does not.)

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

* Localize CommandProcessor: all 48 command strings, 30 locales

CommandProcessor had zero String(localized:) calls — every command
error, usage hint, and the entire /help reference was hardcoded
English. The autocomplete panel (CommandInfo) is fully localized, so a
non-English speaker got localized suggestions while typing and English
the moment anything went wrong or they asked for help.

- 47 literal sites converted to String(localized:)/String(format:)
  with positional specifiers where languages reorder (%1$@, %2$lld).
- /trace's "hop"/"hops" pluralization split into path_one/path_many;
  the "you" chain label localized too.
- helpText and groupUsage become computed so they resolve per-locale.
- 49 command.* keys added with full 30-locale coverage (command
  syntax stays verbatim; only prose translates).
- Copy fix from the audit: "blocked X. you will no longer receive
  messages from them" → "…no longer see their messages" (blocking
  filters at display time; packets still arrive and relay).

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

* Localize the last hardcoded UI strings; wire up two dead translations

The stragglers from the unlocalized-strings audit:

- Nearby push notification: "bitchatters nearby!" title and the
  hand-rolled English pluralization ("1 person around" / "N people
  around") now localize via body_one/body_many.
- Voice recording errors (mic permission, start/too-short/save
  failures) and the "Recording Error" alert title — also brought into
  the lowercase house voice.
- The recording HUD's Cancel label now uses common.cancel.
- "No image selected" in both image pickers.
- The DM screenshot echo "you took a screenshot" (the wire-format
  sibling stays English for Android compat).
- "Voice/Images are only available in mesh chats." had fully
  translated catalog entries in all 30 locales that were never looked
  up — the call sites passed the raw string instead of resolving the
  key. Wired up via String(localized:).

10 new keys x 30 locales.

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

---------

Co-authored-by: jack <jackjackbits@users.noreply.github.com>
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

.github/workflows/fetch_georelays.yml

@@ -1,42 +1,228 @@
-name: Fetch GeoRelays Data
+name: Propose GeoRelay Data Update
 
 on:
   schedule:
-    - cron: '0 6 * * 0'
+    - cron: "0 6 * * 0"
   workflow_dispatch:
 
+# Default to read-only. The publishing job receives only the scopes required
+# to push its branch and publish either a PR or a tracking issue.
 permissions:
-  contents: write
-  pull-requests: write
+  contents: read
+
+concurrency:
+  group: georelay-data-update
+  cancel-in-progress: false
+
+env:
+  SOURCE_REPOSITORY: https://github.com/permissionlesstech/georelays.git
+  UPDATE_BRANCH: automation/georelay-data
+  TRACKING_ISSUE_TITLE: GeoRelay update awaiting pull request
 
 jobs:
-  update-relay-data:
+  propose-relay-data:
+    name: Validate and propose relay data
     runs-on: ubuntu-latest
+    timeout-minutes: 10
+    permissions:
+      contents: write
+      pull-requests: write
+      issues: write
 
     steps:
-      - name: Checkout repository
-        uses: actions/checkout@v4
+      - name: Checkout reviewed base
+        # Pinned actions/checkout v5 so a mutable action tag cannot change the
+        # code that receives this job's write-capable token.
+        uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd
         with:
-          token: ${{ secrets.GITHUB_TOKEN }}
+          ref: main
           fetch-depth: 0
+          # Do not expose the write token to fetch/validation subprocesses.
+          persist-credentials: false
 
-      - name: Fetch GeoRelays
+      - name: Test GeoRelay validator
         run: |
-          wget -q https://raw.githubusercontent.com/permissionlesstech/georelays/refs/heads/main/nostr_relays.csv
-          mv nostr_relays.csv ./relays/online_relays_gps.csv
+          set -euo pipefail
+          python3 -m unittest discover -s scripts/tests -p "test_*.py" -v
 
-      - name: Check for changes
-        id: git-check
+      - name: Fetch candidate over pinned HTTPS policy
+        id: upstream
         run: |
-          git diff --exit-code || echo "changes=true" >> $GITHUB_OUTPUT
-    
-      - name: Commit and push changes
-        if: steps.git-check.outputs.changes == 'true'
+          set -euo pipefail
+          source_commit=$(git ls-remote --refs "$SOURCE_REPOSITORY" refs/heads/main | awk 'NR == 1 { print $1 }')
+          if [[ ! "$source_commit" =~ ^[0-9a-f]{40}$ ]]; then
+            echo "::error::Could not resolve an immutable upstream commit"
+            exit 1
+          fi
+          source_url="https://raw.githubusercontent.com/permissionlesstech/georelays/$source_commit/nostr_relays.csv"
+          effective_url=$(curl --fail --show-error --silent --location --proto "=https" --proto-redir "=https" --tlsv1.2 --max-time 60 --retry 3 --retry-all-errors --output "$RUNNER_TEMP/georelays-candidate.csv" --write-out "%{url_effective}" "$source_url")
+          if [[ "$effective_url" != "$source_url" ]]; then
+            echo "::error::Unexpected GeoRelay redirect target: $effective_url"
+            exit 1
+          fi
+          echo "source_commit=$source_commit" >> "$GITHUB_OUTPUT"
+          echo "source_url=$source_url" >> "$GITHUB_OUTPUT"
+
+      - name: Validate candidate against reviewed baseline
+        id: validation
         run: |
-          git config --local user.email "action@github.com"
-          git config --local user.name "GitHub Action"
-          git add relays/online_relays_gps.csv
-          git commit -m "Automated update of relay data - $(date -u)"
-          git push
+          set -euo pipefail
+          python3 scripts/validate_georelays.py --input "$RUNNER_TEMP/georelays-candidate.csv" --baseline relays/online_relays_gps.csv --output relays/online_relays_gps.csv --github-output "$GITHUB_OUTPUT"
+
+      - name: Check for a reviewed-file change
+        id: changes
+        run: |
+          set -euo pipefail
+          if git diff --quiet -- relays/online_relays_gps.csv; then
+            echo "changed=false" >> "$GITHUB_OUTPUT"
+            echo "Upstream GeoRelay data already matches main." >> "$GITHUB_STEP_SUMMARY"
+          else
+            echo "changed=true" >> "$GITHUB_OUTPUT"
+            git diff --stat -- relays/online_relays_gps.csv
+          fi
+
+      - name: Push automation branch and publish review request
+        if: steps.changes.outputs.changed == 'true'
         env:
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          GH_TOKEN: ${{ github.token }}
+          SOURCE_COMMIT: ${{ steps.upstream.outputs.source_commit }}
+          SOURCE_URL: ${{ steps.upstream.outputs.source_url }}
+          DATA_ROWS: ${{ steps.validation.outputs.data_rows }}
+          UNIQUE_RELAYS: ${{ steps.validation.outputs.unique_relays }}
+          DATA_SHA256: ${{ steps.validation.outputs.sha256 }}
+        run: |
+          set -euo pipefail
+
+          # Scope credential exposure to this final publishing step.
+          gh auth setup-git
+          git config user.name "github-actions[bot]"
+          git config user.email "41898282+github-actions[bot]@users.noreply.github.com"
+
+          git switch -C "$UPDATE_BRANCH"
+          git add -- relays/online_relays_gps.csv
+          git diff --cached --quiet && {
+            echo "::error::Expected a staged GeoRelay data change"
+            exit 1
+          }
+          git commit -m "Update reviewed georelay directory" -m "Upstream-commit: $SOURCE_COMMIT"
+
+          remote_ref="refs/remotes/origin/$UPDATE_BRANCH"
+          if git fetch --no-tags origin "+refs/heads/$UPDATE_BRANCH:$remote_ref" 2>/dev/null; then
+            remote_sha=$(git rev-parse "$remote_ref")
+            git push --force-with-lease="refs/heads/$UPDATE_BRANCH:$remote_sha" origin "HEAD:refs/heads/$UPDATE_BRANCH"
+          else
+            git push origin "HEAD:refs/heads/$UPDATE_BRANCH"
+          fi
+
+          body_file="$RUNNER_TEMP/georelay-pr-body.md"
+          {
+            echo "## Automated GeoRelay data proposal"
+            echo
+            echo "- Source: $SOURCE_URL"
+            echo "- Upstream commit: $SOURCE_COMMIT"
+            echo "- Data rows: $DATA_ROWS"
+            echo "- Unique normalized relays: $UNIQUE_RELAYS"
+            echo "- SHA-256: $DATA_SHA256"
+            echo
+            echo "The candidate passed strict UTF-8, schema, size, row-count, secure-host, coordinate, duplicate-conflict, and baseline-delta validation."
+            echo
+            echo "This PR is intentionally not auto-merged. Review the relay additions/removals before merging."
+          } > "$body_file"
+
+          existing_pr=$(gh pr list --repo "$GITHUB_REPOSITORY" --state open --base main --head "$UPDATE_BRANCH" --json number --jq '.[0].number // empty')
+          pr_error="$RUNNER_TEMP/georelay-pr-error.txt"
+          pr_url=""
+          if [[ -n "$existing_pr" ]]; then
+            if gh pr edit "$existing_pr" --repo "$GITHUB_REPOSITORY" --title "Update reviewed GeoRelay directory" --body-file "$body_file" 2> "$pr_error"; then
+              pr_url=$(gh pr view "$existing_pr" --repo "$GITHUB_REPOSITORY" --json url --jq .url)
+            fi
+          else
+            if created_pr_url=$(gh pr create --repo "$GITHUB_REPOSITORY" --base main --head "$UPDATE_BRANCH" --title "Update reviewed GeoRelay directory" --body-file "$body_file" 2> "$pr_error"); then
+              pr_url="$created_pr_url"
+            fi
+          fi
+
+          tracking_issue_numbers=$(gh issue list --repo "$GITHUB_REPOSITORY" --state open --search "\"$TRACKING_ISSUE_TITLE\" in:title" --limit 100 --json number,title --jq ".[] | select(.title == \"$TRACKING_ISSUE_TITLE\") | .number")
+          tracking_issues=()
+          if [[ -n "$tracking_issue_numbers" ]]; then
+            mapfile -t tracking_issues <<< "$tracking_issue_numbers"
+          fi
+
+          if [[ -n "$pr_url" ]]; then
+            for issue_number in "${tracking_issues[@]}"; do
+              gh issue close "$issue_number" --repo "$GITHUB_REPOSITORY" --comment "A pull request is now available at $pr_url; closing this fallback tracking issue."
+            done
+            echo "Published GeoRelay review PR: $pr_url" >> "$GITHUB_STEP_SUMMARY"
+            exit 0
+          fi
+
+          echo "::warning::GITHUB_TOKEN could not create or update the GeoRelay pull request; publishing the issues-write fallback."
+          if [[ -s "$pr_error" ]]; then
+            cat "$pr_error" >&2
+          fi
+
+          compare_url="https://github.com/${GITHUB_REPOSITORY}/compare/main...${UPDATE_BRANCH}?expand=1"
+          issue_body_file="$RUNNER_TEMP/georelay-tracking-issue-body.md"
+          {
+            echo "## Validated GeoRelay update awaiting review"
+            echo
+            echo "The automation branch was updated, but this workflow token could not create or update the pull request. Use the compare link below to create it manually."
+            echo
+            echo "- Compare and create PR: $compare_url"
+            echo "- Automation branch: $UPDATE_BRANCH"
+            echo "- Source: $SOURCE_URL"
+            echo "- Upstream commit: $SOURCE_COMMIT"
+            echo "- Data rows: $DATA_ROWS"
+            echo "- Unique normalized relays: $UNIQUE_RELAYS"
+            echo "- SHA-256: $DATA_SHA256"
+            echo
+            echo "The snapshot passed the repository's strict validator before the branch was pushed."
+          } > "$issue_body_file"
+
+          if (( ${#tracking_issues[@]} > 0 )); then
+            primary_issue="${tracking_issues[0]}"
+            gh issue edit "$primary_issue" --repo "$GITHUB_REPOSITORY" --title "$TRACKING_ISSUE_TITLE" --body-file "$issue_body_file"
+            issue_url=$(gh issue view "$primary_issue" --repo "$GITHUB_REPOSITORY" --json url --jq .url)
+            for duplicate_issue in "${tracking_issues[@]:1}"; do
+              gh issue close "$duplicate_issue" --repo "$GITHUB_REPOSITORY" --comment "Closing duplicate GeoRelay automation tracking issue; #$primary_issue is canonical."
+            done
+          else
+            issue_url=$(gh issue create --repo "$GITHUB_REPOSITORY" --title "$TRACKING_ISSUE_TITLE" --body-file "$issue_body_file")
+          fi
+
+          # Do not claim success until the fallback issue was confirmed.
+          [[ -n "$issue_url" ]]
+          echo "Published GeoRelay tracking issue fallback: $issue_url" >> "$GITHUB_STEP_SUMMARY"
+
+      - name: Clean obsolete automation review state
+        if: steps.changes.outputs.changed == 'false'
+        env:
+          GH_TOKEN: ${{ github.token }}
+        run: |
+          set -euo pipefail
+          gh auth setup-git
+
+          existing_pr=$(gh pr list --repo "$GITHUB_REPOSITORY" --state open --base main --head "$UPDATE_BRANCH" --json number --jq '.[0].number // empty')
+          if [[ -n "$existing_pr" ]]; then
+            gh pr close "$existing_pr" --repo "$GITHUB_REPOSITORY" --comment "Upstream now matches the reviewed file on main; closing this obsolete automation proposal."
+            echo "Closed obsolete PR #$existing_pr." >> "$GITHUB_STEP_SUMMARY"
+          fi
+
+          tracking_issue_numbers=$(gh issue list --repo "$GITHUB_REPOSITORY" --state open --search "\"$TRACKING_ISSUE_TITLE\" in:title" --limit 100 --json number,title --jq ".[] | select(.title == \"$TRACKING_ISSUE_TITLE\") | .number")
+          if [[ -n "$tracking_issue_numbers" ]]; then
+            while IFS= read -r issue_number; do
+              gh issue close "$issue_number" --repo "$GITHUB_REPOSITORY" --comment "Upstream now matches the reviewed file on main; closing this obsolete automation tracker."
+              echo "Closed obsolete tracking issue #$issue_number." >> "$GITHUB_STEP_SUMMARY"
+            done <<< "$tracking_issue_numbers"
+          fi
+
+          if git ls-remote --exit-code --heads origin "refs/heads/$UPDATE_BRANCH" > /dev/null; then
+            git push origin --delete "$UPDATE_BRANCH"
+            echo "Deleted obsolete automation branch $UPDATE_BRANCH." >> "$GITHUB_STEP_SUMMARY"
+          else
+            ls_remote_status=$?
+            if (( ls_remote_status != 2 )); then
+              echo "::error::Could not inspect the obsolete automation branch"
+              exit "$ls_remote_status"
+            fi
+          fi

.github/workflows/periphery.yml

@@ -0,0 +1,32 @@
+name: Dead Code
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+
+jobs:
+  periphery:
+    name: Periphery scan
+    runs-on: macos-latest
+    timeout-minutes: 30
+    # Blocking, like SwiftLint since #1646. The baseline (committed July 8)
+    # has been stable across a month of merges — the "drop continue-on-error
+    # once the baseline proves stable" condition this job shipped with is met.
+    # Known macOS-scan false positives stay suppressed by the baseline; only
+    # NEW dead code fails the job (--strict below).
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v5
+
+      - name: Install Periphery
+        # homebrew-core formula; the peripheryapp tap lags years behind.
+        run: brew install periphery
+
+      - name: Scan for dead code
+        # Config comes from .periphery.yml; known findings (mostly iOS-only
+        # code invisible to a macOS scan) are suppressed by the committed
+        # baseline. --strict fails the step when NEW dead code appears.
+        run: periphery scan --strict --disable-update-check

.github/workflows/source-manifest.yml

@@ -0,0 +1,112 @@
+name: Source manifest
+
+# Publishes a hash manifest for every tagged release so a copy of the source
+# obtained from somewhere other than this repository can be checked against it.
+#
+# This exists because the repository has been the target of takedown demands.
+# When that succeeds, mirrors appear, and without a manifest there is no way to
+# tell a faithful mirror from a modified one. The manifest is attested to this
+# workflow run, so its own provenance is verifiable with `gh attestation verify`.
+#
+# Scope, stated plainly: this verifies SOURCE. It does not verify any compiled
+# app. See docs/VERIFYING-A-BUILD.md.
+
+on:
+  push:
+    tags:
+      - 'v*'
+  workflow_dispatch:
+    inputs:
+      ref:
+        description: 'Tag or commit to produce a manifest for'
+        required: true
+
+permissions:
+  contents: read
+
+jobs:
+  manifest:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write      # attach the manifest to the release
+      id-token: write      # provenance attestation
+      attestations: write
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          ref: ${{ github.event.inputs.ref || github.ref }}
+          # Full history so the commit the tag names can be recorded exactly.
+          fetch-depth: 0
+
+      - name: Build manifest
+        id: build
+        run: |
+          set -euo pipefail
+          ref_name="${{ github.event.inputs.ref || github.ref_name }}"
+          commit="$(git rev-parse HEAD)"
+          tree="$(git rev-parse HEAD^{tree})"
+
+          # Hash every tracked file, in a stable order, with NUL separation so
+          # paths containing spaces or newlines cannot shift the columns.
+          git ls-files -z \
+            | sort -z \
+            | xargs -0 sha256sum \
+            > files.sha256
+
+          {
+            echo "# bitchat source manifest"
+            echo "#"
+            echo "# ref:    ${ref_name}"
+            echo "# commit: ${commit}"
+            echo "# tree:   ${tree}"
+            echo "# files:  $(wc -l < files.sha256 | tr -d ' ')"
+            echo "#"
+            echo "# Verify a checkout of this ref with:"
+            echo "#   shasum -a 256 -c files.sha256"
+            echo "# Hash checking alone ignores files this manifest does not list, and"
+            echo "# the Xcode project compiles any source file present in the tree. So"
+            echo "# also confirm nothing extra is present:"
+            echo "#   git status --porcelain --ignored   # git checkout: must print nothing"
+            echo "# or, for a tarball, diff this manifest's path list against find(1)."
+            echo "# Full instructions: docs/VERIFYING-A-BUILD.md"
+            echo "# The git tree hash above is the single value covering all tracked content:"
+            echo "#   git rev-parse HEAD^{tree}"
+            echo "#"
+          } > SOURCE-MANIFEST.txt
+          cat files.sha256 >> SOURCE-MANIFEST.txt
+
+          echo "commit=${commit}" >> "$GITHUB_OUTPUT"
+          echo "tree=${tree}" >> "$GITHUB_OUTPUT"
+
+      - name: Self-check the manifest
+        run: |
+          set -euo pipefail
+          # A manifest that does not validate against the tree it was made from
+          # is worse than none, so fail loudly rather than publishing it.
+          grep -v '^#' SOURCE-MANIFEST.txt > check.sha256
+          sha256sum -c check.sha256 > /dev/null
+          echo "manifest validates against this checkout"
+
+      - name: Attest the manifest
+        uses: actions/attest-build-provenance@v1
+        with:
+          subject-path: SOURCE-MANIFEST.txt
+
+      - uses: actions/upload-artifact@v4
+        with:
+          name: source-manifest
+          path: SOURCE-MANIFEST.txt
+
+      - name: Attach to release
+        if: startsWith(github.ref, 'refs/tags/')
+        env:
+          GH_TOKEN: ${{ github.token }}
+        run: |
+          set -euo pipefail
+          # A tag may be pushed before its release exists; only attach when
+          # there is a release to attach to, and never fail the run over it.
+          if gh release view "${{ github.ref_name }}" >/dev/null 2>&1; then
+            gh release upload "${{ github.ref_name }}" SOURCE-MANIFEST.txt --clobber
+          else
+            echo "no release for ${{ github.ref_name }} yet; manifest is available as a workflow artifact"
+          fi

.github/workflows/swift-tests.yml

@@ -12,7 +12,10 @@ jobs:
     runs-on: macos-latest
     # A hung test must fail fast, not hold a runner for GitHub's 360-minute
     # default (observed: intermittent app-suite hangs starving the queue).
-    timeout-minutes: 15
+    # The long steps carry tighter individual bounds (5-minute test watchdog,
+    # 6-minute benchmark step, 10-minute floor gate that may re-run the
+    # benchmarks up to twice on a noisy runner); this is the backstop.
+    timeout-minutes: 25
 
     strategy:
       fail-fast: false # Don't cancel other matrix jobs when one fails
@@ -29,17 +32,22 @@ jobs:
       - name: Checkout code
         uses: actions/checkout@v5
 
-      - name: Set up Swift
-        uses: swift-actions/setup-swift@v2
+      # Use the Xcode-bundled Swift toolchain: it always matches the SDK on
+      # the runner image. A standalone swift.org toolchain (setup-swift) broke
+      # whenever the image's Xcode moved ahead of it ("this SDK is not
+      # supported by the compiler").
+      - name: Note toolchain version (cache key)
+        id: swift-version
+        run: echo "version=$(swift --version 2>/dev/null | head -1 | shasum | cut -c1-12)" >> "$GITHUB_OUTPUT"
 
       - name: Cache build artifacts
         uses: actions/cache@v4
         with:
           path: ${{ matrix.path }}/.build
-          key: ${{ runner.os }}-${{ matrix.name }}-${{ hashFiles(format('{0}/**/*.swift', matrix.path), format('{0}/**/Package.resolved', matrix.path)) }}
+          key: ${{ runner.os }}-${{ steps.swift-version.outputs.version }}-${{ matrix.name }}-${{ 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 }}-
+            ${{ runner.os }}-${{ steps.swift-version.outputs.version }}-${{ matrix.name }}-${{ hashFiles(format('{0}/**/Package.resolved', matrix.path)) }}
+            ${{ runner.os }}-${{ steps.swift-version.outputs.version }}-${{ matrix.name }}-
 
       - name: Build tests
         # Built separately so the hang watchdog below times only test
@@ -86,6 +94,24 @@ jobs:
           kill "$watchdog_pid" 2>/dev/null || true
           exit "$status"
 
+      # Read coverage before the serial benchmark command below rebuilds the
+      # test binary without instrumentation. Reporting against that newer
+      # binary makes llvm-cov reject the profile as out of date.
+      # Informational only: there is deliberately no percentage threshold, but
+      # a broken/missing report is a CI configuration error and must be visible.
+      - name: Coverage summary
+        run: |
+          BIN_PATH=$(swift build --show-bin-path --package-path ${{ matrix.path }})
+          PROF="$BIN_PATH/codecov/default.profdata"
+          XCTEST=$(find "$BIN_PATH" -maxdepth 1 -name '*.xctest' | head -1)
+          BINARY="$XCTEST/Contents/MacOS/$(basename "$XCTEST" .xctest)"
+          if [ ! -f "$PROF" ] || [ ! -f "$BINARY" ]; then
+            echo "::error::Coverage profile or test binary is missing"
+            exit 1
+          fi
+          xcrun llvm-cov report "$BINARY" -instr-profile "$PROF" \
+            -ignore-filename-regex='(Tests|\.build|checkouts|Mocks|_PreviewHelpers)'
+
       # Benchmarks run serially on an otherwise idle runner for stable
       # numbers; BITCHAT_PERF_LOG captures the PERF[...] lines for the gate.
       - name: Run performance benchmarks (serial)
@@ -97,31 +123,20 @@ jobs:
 
       # Order-of-magnitude performance regression gate. Floors are deliberately
       # generous (see bitchatTests/Performance/perf-floors.json) so this
-      # catches algorithmic regressions, never runner variance.
+      # catches algorithmic regressions, never runner variance. If a metric
+      # still lands below floor (a saturated runner can dip one), the script
+      # re-runs the benchmarks — appending to the same log and keeping each
+      # benchmark's best value per metric — so noise clears on retry while a
+      # real regression fails every attempt. Floors are never lowered by this.
       - name: Performance floor gate
         if: matrix.name == 'app'
+        timeout-minutes: 10
         run: ./scripts/check-perf-floors.sh perf-output.log
 
-      # Informational only: surfaces per-file and total line coverage in the
-      # job log so coverage trends are visible on every PR. No thresholds —
-      # this must never be the reason a build goes red.
-      - name: Coverage summary
-        run: |
-          BIN_PATH=$(swift build --show-bin-path --package-path ${{ matrix.path }})
-          PROF="$BIN_PATH/codecov/default.profdata"
-          XCTEST=$(find "$BIN_PATH" -maxdepth 1 -name '*.xctest' | head -1)
-          BINARY="$XCTEST/Contents/MacOS/$(basename "$XCTEST" .xctest)"
-          if [ -f "$PROF" ] && [ -f "$BINARY" ]; then
-            xcrun llvm-cov report "$BINARY" -instr-profile "$PROF" \
-              -ignore-filename-regex='(Tests|\.build|checkouts|Mocks|_PreviewHelpers)' || true
-          else
-            echo "No coverage data found; skipping summary."
-          fi
-
-  # SPM tests above only compile the macOS slice; this job covers the
-  # iOS-conditional code paths (UIKit, CoreBluetooth restoration, etc.).
+  # SPM tests do not link the shipping app targets. This job covers the
+  # iOS-conditional paths and both universal Release link configurations.
   ios-build:
-    name: Build iOS app (simulator)
+    name: Build Release apps (universal)
     runs-on: macos-latest
     timeout-minutes: 15
 
@@ -129,14 +144,147 @@ jobs:
       - name: Checkout code
         uses: actions/checkout@v5
 
+      - name: Check clean recipe safety
+        run: bash scripts/check-just-clean-safety.sh
+
       - name: Build iOS (simulator, no signing)
-        # arm64 only: the vendored arti.xcframework has no x86_64 simulator slice.
+        # Build both simulator architectures so CI validates every vendored
+        # Arti simulator slice and the configuration that ships.
+        run: |
+          set -o pipefail
+          xcodebuild -project bitchat.xcodeproj \
+            -scheme "bitchat (iOS)" \
+            -configuration Release \
+            -sdk iphonesimulator \
+            -destination 'generic/platform=iOS Simulator' \
+            ARCHS='arm64 x86_64' \
+            ONLY_ACTIVE_ARCH=NO \
+            CODE_SIGNING_ALLOWED=NO \
+            build
+
+      - name: Build macOS (universal, no signing)
+        run: |
+          set -o pipefail
+          xcodebuild -project bitchat.xcodeproj \
+            -scheme "bitchat (macOS)" \
+            -configuration Release \
+            -destination 'generic/platform=macOS' \
+            ARCHS='arm64 x86_64' \
+            ONLY_ACTIVE_ARCH=NO \
+            CODE_SIGNING_ALLOWED=NO \
+            build
+
+  # The SwiftPM matrix runs on macOS and cannot execute UIKit/CoreBluetooth
+  # conditional tests. Build the shared iOS test target and run it on the first
+  # available iPhone simulator from the runner image instead of hard-coding a
+  # model that changes when GitHub updates Xcode. The suite intentionally runs
+  # in one test runner: a number of integration tests exercise process-global
+  # stores and notification centers, so overlapping workers can corrupt each
+  # other's fixtures and turn sub-second tests into multi-minute timeouts.
+  ios-tests:
+    name: Run iOS simulator tests
+    runs-on: macos-latest
+    timeout-minutes: 20
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v5
+
+      # Some runner images list only placeholder destinations (rows carrying
+      # "error:" or "unavailable") or ship the selected Xcode without a
+      # matching iOS simulator runtime, so this walks three paths in order:
+      # a usable xcodebuild destination, an existing simctl device, and
+      # finally creating a device from the newest installed iOS runtime.
+      - name: Select available iPhone simulator
+        id: destination
+        run: |
+          set -uo pipefail
+          destinations=$(xcodebuild -project bitchat.xcodeproj -scheme "bitchat (iOS)" -showdestinations 2>/dev/null || true)
+          destination_id=$(awk -F'id:' '
+            /platform:iOS Simulator/ && /name:iPhone/ \
+              && !/error/ && !/unavailable/ && !found {
+              value=$2
+              sub(/,.*/, "", value)
+              gsub(/^[[:space:]]+|[[:space:]]+$/, "", value)
+              print value
+              found=1
+            }
+          ' <<< "$destinations")
+
+          if [ -n "$destination_id" ]; then
+            echo "Selected destination via xcodebuild -showdestinations: $destination_id"
+          else
+            echo "No usable iPhone destination in -showdestinations output; falling back to simctl"
+            destination_id=$(xcrun simctl list devices available --json | jq -r '
+              [.devices | to_entries[]
+                | select(.key | contains("iOS"))
+                | .value[]
+                | select(.isAvailable and (.name | startswith("iPhone")))]
+              | first.udid // empty')
+            if [ -n "$destination_id" ]; then
+              echo "Selected existing simctl device: $destination_id"
+            else
+              echo "No available iPhone simulator device; creating one"
+              # Newest installed iOS runtime plus an iPhone device type that
+              # runtime itself reports as supported, so the pair always match.
+              create_spec=$(xcrun simctl list runtimes --json | jq -r '
+                [.runtimes[] | select(.platform == "iOS" and .isAvailable)]
+                | sort_by(.version | split(".") | map(tonumber))
+                | last // empty
+                | .identifier as $runtime
+                | ([(.supportedDeviceTypes // [])[]
+                    | select(.productFamily == "iPhone"
+                        or (.name // "" | startswith("iPhone")))]
+                  | first.identifier // empty) as $devicetype
+                | "\($devicetype) \($runtime)"')
+              read -r devicetype runtime <<< "$create_spec" || true
+              if [ -z "${devicetype:-}" ] || [ -z "${runtime:-}" ]; then
+                echo "::error::No iPhone simulator destination found and none creatable (no installed iOS runtime with an iPhone device type)"
+                exit 1
+              fi
+              destination_id=$(xcrun simctl create ci-iphone "$devicetype" "$runtime") || {
+                echo "::error::simctl create failed for $devicetype on $runtime"
+                exit 1
+              }
+              echo "Created simulator $destination_id ($devicetype, $runtime)"
+            fi
+          fi
+
+          echo "Using iPhone simulator destination id: $destination_id"
+          echo "id=$destination_id" >> "$GITHUB_OUTPUT"
+
+      - name: Run iOS tests
         run: |
           set -o pipefail
           xcodebuild -project bitchat.xcodeproj \
             -scheme "bitchat (iOS)" \
             -sdk iphonesimulator \
-            -destination 'generic/platform=iOS Simulator' \
-            ARCHS=arm64 \
+            -destination "platform=iOS Simulator,id=${{ steps.destination.outputs.id }}" \
+            -parallel-testing-enabled NO \
             CODE_SIGNING_ALLOWED=NO \
-            build
+            test
+
+  # Blocking since the backlog reached zero (all violations fixed; rules the
+  # codebase deliberately breaks are disabled in .swiftlint.yml). --strict
+  # promotes warnings to errors so new violations fail the job. Runs in a
+  # pinned container (no Xcode plugin, no pbxproj changes) so it can never
+  # break the documented xcodebuild path.
+  lint:
+    name: SwiftLint
+    runs-on: ubuntu-latest
+    timeout-minutes: 15
+    # This job runs a third-party container image, so give it the least
+    # privilege we can: a read-only token, and no credentials left in the
+    # checkout for the container to find.
+    permissions:
+      contents: read
+    container:
+      # Tag for readability, digest for immutability (tags can be repointed).
+      # Bump both together, deliberately — never a floating tag.
+      image: ghcr.io/realm/swiftlint:0.65.0@sha256:a482729f4b58741875af1566f23397f3f6db300372756fc31606d0a4527fab9e
+    steps:
+      - uses: actions/checkout@v5
+        with:
+          persist-credentials: false
+      - name: Run SwiftLint
+        run: swiftlint lint --strict --reporter github-actions-logging

.gitignore

@@ -80,3 +80,4 @@ build.log
 
 # Local configs
 Local.xcconfig
+*.profraw

.periphery.baseline.json

@@ -0,0 +1 @@
+{"v1":{"usrs":["param-buf-arti_bootstrap_summary(_:_:)-s:3Tor22arti_bootstrap_summary33_954FD7701B4E47ABB5F166D1CF862DC9LLys5Int32VSpys4Int8VG_AEtF","param-dataDir-arti_start(_:_:)-s:3Tor10arti_start33_954FD7701B4E47ABB5F166D1CF862DC9LLys5Int32VSPys4Int8VG_s6UInt16VtF","param-len-arti_bootstrap_summary(_:_:)-s:3Tor22arti_bootstrap_summary33_954FD7701B4E47ABB5F166D1CF862DC9LLys5Int32VSpys4Int8VG_AEtF","param-socksPort-arti_start(_:_:)-s:3Tor10arti_start33_954FD7701B4E47ABB5F166D1CF862DC9LLys5Int32VSPys4Int8VG_s6UInt16VtF","s:13BitFoundation16PeerCapabilitiesV8wifiBulkACvpZ","s:13BitFoundation18KeychainReadResultO18isRecoverableErrorSbvp","s:13BitFoundation23KeychainManagerProtocolP11secureClearyySSzF","s:18bitchatTests_macOS12MockKeychainC11secureClearyySSzF","s:18bitchatTests_macOS20TrackingMockKeychainC11resetCountsyyF","s:18bitchatTests_macOS20TrackingMockKeychainC11secureClearyySSzF","s:18bitchatTests_macOS20TrackingMockKeychainC25totalSecureClearCallCountSivp","s:18bitchatTests_macOS20TrackingMockKeychainC26secureClearStringCallCountSivp","s:18bitchatTests_macOS20TrackingMockKeychainC27_secureClearStringCallCount06_AB6D1M24FD239F2969C82F4108818260LLSivp","s:18bitchatTests_macOS24FailingCacheSaveKeychain33_22380C7A11A569A0B83FA83F34C498A7LLC11secureClearyySSzF","s:18bitchatTests_macOS24MockGeohashPresenceTimer33_483587EFB96650EE130EFB09BBA2A1AALLC7handleryycvp","s:3Tor0A7ManagerC21goDormantOnBackgroundyyF","s:7bitchat10AppRuntimeC24handleScreenshotCaptured33_C8B369AD8BC1D9963A50CEDA77A4332ALLyyF","s:7bitchat10AppRuntimeC33handleDidBecomeActiveNotificationyyF","s:7bitchat10BLEServiceC18logBluetoothStatus33_69191C53E68500C17D98DBCF2BDA7100LLyySSF","s:7bitchat10BLEServiceC18logBluetoothStatusyySSF","s:7bitchat10BLEServiceC20centralRestorationID33_69191C53E68500C17D98DBCF2BDA7100LLSSvpZ","s:7bitchat10BLEServiceC22captureBluetoothStatus33_69191C53E68500C17D98DBCF2BDA7100LL7contextySS_tF","s:7bitchat10BLEServiceC23peripheralRestorationID33_69191C53E68500C17D98DBCF2BDA7100LLSSvpZ","s:7bitchat10BLEServiceC29scheduleBluetoothStatusSample33_69191C53E68500C17D98DBCF2BDA7100LL5after7contextySd_SStF","s:7bitchat10QRScanViewV8isActiveSbvp","s:7bitchat15BLEPeerRegistryV5countSivp","s:7bitchat15KeychainManagerC11secureClearyySSzF","s:7bitchat15PaymentChipViewV7openURL33_10AC50641B1EBCD52E5092A2E521D236LL7SwiftUI13OpenURLActionVvp","s:7bitchat15TransportConfigO29uiBatchDispatchStaggerSecondsSdvpZ","s:7bitchat15TransportConfigO35uiShareExtensionDismissDelaySecondsSdvpZ","s:7bitchat15TransportConfigO38bleBackgroundPendingConnectSlotReserveSivpZ","s:7bitchat17GossipSyncManagerC10persistNowyyF","s:7bitchat17NostrRelayManagerC15InboundEventKey33_E4160FE8A9A2C9D6308EAAD5A8B5CB07LLV7eventIDSSvp","s:7bitchat18BLERadioControllerC14candidateCountSivp","s:7bitchat25LocationNotesDependenciesV3now10Foundation4DateVycvp","s:7bitchat25NWPathReachabilityMonitorC7monitor33_84633C9DBCAF57538179C1E04DB8E015LL7Network0bD0CSgvp"]}}

.periphery.yml

@@ -0,0 +1,21 @@
+# Periphery dead-code scan configuration (https://github.com/peripheryapp/periphery)
+#
+# CI runs the macOS scheme only (an iOS scan needs a device destination and
+# doubles the build time). macOS-only scans falsely flag iOS-only code —
+# state restoration, screenshot handlers, background BLE sampling — so those
+# findings live in .periphery.baseline.json rather than being "fixed".
+# When auditing by hand, scan BOTH schemes and intersect:
+#   periphery scan --schemes "bitchat (iOS)" -- -destination 'generic/platform=iOS' ARCHS=arm64
+project: bitchat.xcodeproj
+schemes:
+  - bitchat (macOS)
+retain_swift_ui_previews: true
+# Codable properties are (de)serialized via synthesized conformances the
+# indexer doesn't always attribute reads to: PrekeyBundleStore.StoredBundle
+# .noiseKey flaked CI as "assign-only" even while read in loadFromDisk —
+# and slipped past its baselined USR. Retaining Codable properties outright
+# is deterministic; a truly-dead Codable field is a persisted-format change
+# anyway, never a safe mechanical delete.
+retain_codable_properties: true
+relative_results: true
+baseline: .periphery.baseline.json

.swiftlint.yml

@@ -0,0 +1,36 @@
+# Build artifacts and generated sources; keeps local `swiftlint` runs clean
+# (CI checkouts are fresh, so this only matters in a working tree).
+excluded:
+  - .build
+  - .claude
+  - .device-lab
+  - .swiftpm
+  - .DerivedData
+  - DerivedData
+  - build
+  - localPackages/*/.build
+
+disabled_rules:
+  - line_length
+  - type_name
+  - identifier_name
+  - statement_position
+  - implicit_optional_initialization
+  - force_try
+  - vertical_whitespace
+  - for_where
+  - control_statement
+  - void_function_in_ternary
+  - redundant_discardable_let  # SwiftUI breaks without it
+  - todo  # TODOs that cite a tracked issue are deliberate markers, not lint debt
+  # To be enabled as we fix the issues
+  - trailing_whitespace
+  - cyclomatic_complexity
+  - function_body_length
+  - function_parameter_count
+  - type_body_length
+  - file_length
+  - large_tuple
+  - force_cast
+  - multiple_closures_with_trailing_closure
+  - nesting

Configs/Local.xcconfig.example

@@ -3,3 +3,6 @@ DEVELOPMENT_TEAM = ABC123
 
 // Unique bundle id to be able to register and run locally
 PRODUCT_BUNDLE_IDENTIFIER = chat.bitchat.$(DEVELOPMENT_TEAM)
+
+// App and share extension must use an App Group registered to your team.
+APP_GROUP_ID = group.chat.bitchat.$(DEVELOPMENT_TEAM)

Configs/Release.xcconfig

@@ -1,4 +1,4 @@
-MARKETING_VERSION = 1.5.2
+MARKETING_VERSION = 1.7.1
 CURRENT_PROJECT_VERSION = 1
 
 IPHONEOS_DEPLOYMENT_TARGET = 16.0

Justfile

@@ -1,107 +1,66 @@
-# BitChat macOS Build Justfile
-# Handles temporary modifications needed to build and run on macOS
+# BitChat developer commands
+#
+# Builds use a repository-local, ignored DerivedData directory. No recipe
+# patches, restores, or removes tracked project/configuration files.
+
+project := "bitchat.xcodeproj"
+macos_scheme := "bitchat (macOS)"
+ios_scheme := "bitchat (iOS)"
+derived_data := ".DerivedData"
 
-# Default recipe - shows available commands
 default:
-    @echo "BitChat macOS Build Commands:"
-    @echo "  just run     - Build and run the macOS app"
-    @echo "  just build   - Build the macOS app only"
-    @echo "  just clean   - Clean build artifacts and restore original files"
-    @echo "  just check   - Check prerequisites"
-    @echo ""
-    @echo "Original files are preserved - modifications are temporary for builds only"
+    @echo "BitChat developer commands:"
+    @echo "  just run                Build and run the macOS app"
+    @echo "  just build              Build the macOS app without signing"
+    @echo "  just test               Run the SwiftPM test suite"
+    @echo "  just test-ios           Run tests on the iPhone 17 simulator"
+    @echo "  just clean              Remove repo-local build artifacts only"
+    @echo "  just nuke               Also remove nested package build caches"
+    @echo "  just check              Validate the development environment"
 
-# Check prerequisites
-check:
+# Static guard against reintroducing source-restoring or source-deleting clean
+# behavior. CI runs the same script directly.
+check-clean-safety:
+    @bash scripts/check-just-clean-safety.sh
+
+check: check-clean-safety
     @echo "Checking prerequisites..."
-    @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"
+    @command -v xcodebuild >/dev/null 2>&1 || (echo "❌ xcodebuild not found. Install full Xcode." && exit 1)
+    @developer_dir="$(xcode-select -p 2>/dev/null)"; case "$developer_dir" in *.app/Contents/Developer) ;; *) echo "❌ Full Xcode is not selected. Run: sudo xcode-select -s /Applications/Xcode.app/Contents/Developer"; exit 1;; esac
+    @xcodebuild -version
+    @echo "✅ Development environment ready (a signing identity is not required for just build)"
 
-# Backup original files
-backup:
-    @echo "Backing up original project configuration..."
-    @if [ -f bitchat.xcodeproj/project.pbxproj ]; then cp bitchat.xcodeproj/project.pbxproj bitchat.xcodeproj/project.pbxproj.backup; fi
-    @if [ -f bitchat/Info.plist ]; then cp bitchat/Info.plist bitchat/Info.plist.backup; fi
-
-# Restore original files
-restore:
-    @echo "Restoring original project configuration..."
-    @if [ -f project.yml.backup ]; then mv project.yml.backup project.yml; fi
-    @# Restore iOS-specific files
-    @if [ -f bitchat/LaunchScreen.storyboard.ios ]; then mv bitchat/LaunchScreen.storyboard.ios bitchat/LaunchScreen.storyboard; fi
-    @# Use git to restore all modified files except Justfile
-    @git checkout -- project.yml bitchat.xcodeproj/project.pbxproj bitchat/Info.plist 2>/dev/null || echo "⚠️  Could not restore some files with git"
-    @# Remove any backup files
-    @rm -f bitchat.xcodeproj/project.pbxproj.backup bitchat/Info.plist.backup 2>/dev/null || true
-
-# Apply macOS-specific modifications
-patch-for-macos: backup
-    @echo "Temporarily hiding iOS-specific files for macOS build..."
-    @# Move iOS-specific files out of the way temporarily
-    @if [ -f bitchat/LaunchScreen.storyboard ]; then mv bitchat/LaunchScreen.storyboard bitchat/LaunchScreen.storyboard.ios; fi
-
-# Build the macOS app
-build: #check generate
+build: check
     @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 "{{project}}" -scheme "{{macos_scheme}}" -configuration Debug -derivedDataPath "{{derived_data}}" CODE_SIGNING_ALLOWED=NO build
 
-# Run the macOS app
 run: build
-    @echo "Launching BitChat..."
-    @find ~/Library/Developer/Xcode/DerivedData -name "bitchat.app" -path "*/Debug/*" -not -path "*/Index.noindex/*" | head -1 | xargs -I {} open "{}"
+    @app="{{derived_data}}/Build/Products/Debug/bitchat.app"; test -d "$app" || (echo "❌ Built app not found at $app" && exit 1); open "$app"
 
-# Clean build artifacts and restore original files
-clean: restore
-    @echo "Cleaning build artifacts..."
-    @rm -rf ~/Library/Developer/Xcode/DerivedData/bitchat-* 2>/dev/null || true
-    @# Only remove the generated project if we have a backup, otherwise use git
-    @if [ -f bitchat.xcodeproj/project.pbxproj.backup ]; then \
-        rm -rf bitchat.xcodeproj; \
-    else \
-        git checkout -- bitchat.xcodeproj/project.pbxproj 2>/dev/null || echo "⚠️  Could not restore project.pbxproj"; \
-    fi
-    @rm -f project-macos.yml 2>/dev/null || true
-    @echo "✅ Cleaned and restored original files"
+# Backward-compatible alias for the old quick-run recipe.
+dev-run: run
 
-# Quick run without cleaning (for development)
-dev-run: check
-    @echo "Quick development build..."
-    @xcodebuild -project bitchat.xcodeproj -scheme "bitchat_macOS" -configuration Debug CODE_SIGN_IDENTITY="" CODE_SIGNING_REQUIRED=NO CODE_SIGN_ENTITLEMENTS="" build
-    @find ~/Library/Developer/Xcode/DerivedData -name "bitchat.app" -path "*/Debug/*" -not -path "*/Index.noindex/*" | head -1 | xargs -I {} open "{}"
+test:
+    @swift test
+
+test-ios: check
+    @xcodebuild -project "{{project}}" -scheme "{{ios_scheme}}" -sdk iphonesimulator -destination 'platform=iOS Simulator,name=iPhone 17' -derivedDataPath "{{derived_data}}" test
+
+# Artifact-only cleanup. In particular, this recipe never invokes Git and
+# never writes, moves, restores, or removes source/configuration files.
+clean:
+    @echo "Cleaning repo-local build artifacts..."
+    @rm -rf -- "{{derived_data}}" ".build"
+    @echo "✅ Cleaned {{derived_data}} and .build; tracked files were untouched"
+
+# Retain the familiar command, but keep it artifact-only as well.
+nuke: clean
+    @echo "Cleaning nested package build caches..."
+    @find localPackages -type d -name .build -prune -exec rm -rf -- {} +
+    @rm -rf -- ".cache"
+    @echo "✅ Removed repository build caches; tracked files were untouched"
 
-# Show app info
 info:
-    @echo "BitChat - Decentralized Mesh Messaging"
-    @echo "======================================"
-    @echo "• Native macOS SwiftUI app"
-    @echo "• Bluetooth LE mesh networking"
-    @echo "• End-to-end encryption"
-    @echo "• No internet required"
-    @echo "• Works offline with nearby devices"
-    @echo ""
-    @echo "Requirements:"
-    @echo "• macOS 13.0+ (Ventura)"
-    @echo "• Bluetooth LE capable Mac"
-    @echo "• Physical device (no simulator support)"
-    @echo ""
-    @echo "Usage:"
-    @echo "• Set nickname and start chatting"
-    @echo "• Use /join #channel for group chats"
-    @echo "• Use /msg @user for private messages"
-    @echo "• Triple-tap logo for emergency wipe"
-
-# Force clean everything (nuclear option)
-nuke:
-    @echo "🧨 Nuclear clean - removing all build artifacts and backups..."
-    @rm -rf ~/Library/Developer/Xcode/DerivedData/bitchat-* 2>/dev/null || true
-    @rm -rf bitchat.xcodeproj 2>/dev/null || true
-    @rm -f bitchat.xcodeproj/project.pbxproj.backup 2>/dev/null || true
-    @rm -f bitchat/Info.plist.backup 2>/dev/null || true
-    @# Restore iOS-specific files if they were moved
-    @if [ -f bitchat/LaunchScreen.storyboard.ios ]; then mv bitchat/LaunchScreen.storyboard.ios bitchat/LaunchScreen.storyboard; fi
-    @git checkout bitchat.xcodeproj/project.pbxproj bitchat/Info.plist 2>/dev/null || echo "⚠️  Not a git repo or no changes to restore"
-    @echo "✅ Nuclear clean complete"
+    @echo "BitChat - decentralized mesh messaging"
+    @echo "macOS 13+ and iOS 16+"
+    @echo "Bluetooth mesh behavior requires physical Bluetooth-capable devices"

PRIVACY_POLICY.md

@@ -1,165 +1,160 @@
 # bitchat Privacy Policy
 
-*Last updated: June 2026*
+*Last updated: July 2026*
 
 ## Our Commitment
 
-bitchat is designed with privacy as its foundation. We believe private communication is a fundamental human right. This policy explains how bitchat protects your privacy.
+bitchat is designed for private, account-free communication. This policy describes what the app keeps on your device, what it sends when you use mesh or optional internet features, and how long local data can remain.
 
 ## Summary
 
-- **No personal data collection** - We don't collect names, emails, or phone numbers
-- **No accounts or company servers** - Mesh chat works peer-to-peer; optional Nostr features use public or user-selected relays
-- **No tracking** - We have no analytics, telemetry, or user tracking
-- **Open source** - You can verify these claims by reading our code
+- **No project-operated accounts or messaging servers** — Bluetooth mesh is peer-to-peer; optional internet features use public or user-selected Nostr relays.
+- **No analytics, advertising, telemetry, or tracking** — the app does not contain an analytics or advertising SDK.
+- **No sale of data** — the project does not sell user data or build advertising profiles.
+- **Open source** — the storage, networking, and cryptography described here can be inspected in the source code.
 
-## What Information bitchat Stores
+## What bitchat Stores on Your Device
 
-### On Your Device Only
+1. **Identity and cryptographic keys**
+   - Noise, signing, group, prekey, and optional Nostr identity material is generated locally.
+   - Secret keys are stored in the system keychain as device-only items. Public keys are shared when required for messaging, verification, groups, or Nostr events.
+   - Keys remain until they are rotated, removed by the relevant feature, or erased with panic wipe. Because operating-system keychains can outlive an uninstall, bitchat records a non-secret install marker and deletes surviving app keys before use after a later reinstall.
 
-1. **Identity Keys**
-   - Cryptographic private keys generated on first launch or when optional Nostr identities are created
-   - Stored locally in your device's secure storage
-   - Allows you to maintain "favorite" relationships across app restarts
-   - Private keys never leave your device; public keys are shared when needed for messaging
+2. **Nickname, preferences, and relationships**
+   - Your nickname, settings, favorites, petnames, read-receipt identifiers, and bounded operational metadata are stored locally.
+   - The share extension can retain one item you choose to share in the app-group preferences for up to 24 hours. The app shows the destination and a preview for review; it does not send the item automatically. The item is cleared when you add it to the composer, cancel, panic-wipe, or it expires.
 
-2. **Nickname**
-   - The display name you choose (or auto-generated)
-   - Stored only on your device
-   - Shared with peers you communicate with
+3. **Private group state**
+   - Group names, rosters, creator identity, and key epoch are stored as protected files in Application Support.
+   - Current group keys are stored in the keychain. Group state remains until you leave or remove the group, panic-wipe the app, or remove the app.
 
-3. **Message History** (if enabled)
-   - When room owners enable retention, messages are saved locally
-   - Stored encrypted on your device
-   - You can delete this at any time
+4. **Queued and carried private messages**
+   - An outgoing private message that has not been acknowledged may remain for up to 24 hours in a bounded, encrypted outbox. The outbox is sealed with ChaCha20-Poly1305 and its key is stored in the keychain.
+   - A device acting as a courier may store a bounded opaque end-to-end encrypted envelope for another user for up to 24 hours. The courier cannot read its message content.
+   - A panic wipe deletes both stores.
 
-4. **Favorite Peers**
-   - Public keys of peers you mark as favorites
-   - Stored only on your device
-   - Allows you to recognize these peers in future sessions
+5. **Recent public mesh messages and notices**
+   - Signed public mesh messages may be kept in a protected local gossip archive for up to 6 hours so they can cross mesh partitions and survive a relaunch.
+   - Public bulletin-board posts and deletion tombstones persist until the post's author-selected expiry, at most seven days. Both stores are bounded and panic-wipeable.
+   - These items are public to the mesh or board where they are posted; they are not confidential messages.
 
-5. **Optional Location Channel State**
-   - Your selected geohash channel, bookmarked geohashes, teleport flags, and bookmark display names
-   - Stored locally on your device so the location-channel UI can restore your choices
-   - Per-geohash Nostr identities are derived locally from a device seed stored in secure storage
-   - Exact latitude and longitude are not persisted by bitchat
+6. **Media attachments**
+   - Voice notes and images you send or receive can be stored under Application Support so they remain playable while referenced by the app.
+   - Incoming media is subject to a 100 MB quota with oldest-file eviction. All stored media, sent and received, is also deleted once it is more than seven days old, and immediately by panic wipe or app removal.
 
-### Temporary Session Data
+7. **Optional location-channel state**
+   - Your selected geohash channel, bookmarks, teleport flags, and bookmark display names are stored locally so the UI can restore them.
+   - Per-geohash Nostr identities are derived locally from a device seed stored in the keychain.
+   - bitchat does not persist exact latitude or longitude and does not include exact coordinates in mesh or Nostr messages.
 
-During each session, bitchat temporarily maintains:
-- Active peer connections (forgotten when app closes)
-- Routing information for message delivery
-- Cached messages for offline peers (12 hours max)
-- Your current location while optional location channels are enabled, used locally to compute geohash channels and friendly place names
+## Temporary Session Data
 
-## What Information is Shared
+While running, bitchat maintains active connections, routing state, deduplication state, and bounded in-memory conversation timelines. Closing the app clears the in-memory timelines and active connections, but it does not erase the persistent stores listed above.
 
-### With Other bitchat Users
+## What Is Shared
 
-When you use bitchat, nearby peers can see:
-- Your chosen nickname
-- Your ephemeral public key (changes each session)
-- Messages you send to public rooms or directly to them
-- Your approximate Bluetooth signal strength (for connection quality)
+### With Nearby Mesh Users
 
-### With Room Members
+Depending on the feature you use, nearby peers can receive:
 
-When you join a password-protected room:
-- Your messages are visible to others with the password
-- Your nickname appears in the member list
-- Room owners can see you've joined
+- Your chosen nickname and public Noise/signing identity material.
+- Announce metadata such as supported capability flags and a bounded list of short direct-neighbor identifiers. When the bridge is enabled, an announce can also include its coarse rendezvous geohash cell.
+- Public mesh messages, public notices, and group-control packets you intentionally send.
+- Private ciphertext addressed to them, or opaque courier ciphertext they agree to carry.
+- Radio metadata available to the receiver, such as approximate Bluetooth signal strength.
 
-### With Nostr Relays (Optional Features)
+Noise identity keys can persist across sessions; do not treat them as anonymous identifiers. Panic wipe rotates local identity state.
 
-If you enable Nostr-backed features:
-- Private fallback messages to mutual favorites are sent as encrypted NIP-17 gift wraps. Relays can see event metadata, but not message content.
-- Public location-channel messages, location notes, and presence are scoped with geohash tags. Relays and other participants can see the geohash tag, event kind, timestamp, and public key used for that geohash.
-- Exact GPS coordinates are not included in Nostr events by bitchat. The geohash precision you choose can still reveal an approximate area, from region-level to building-level.
-- Automatic presence heartbeats are limited to low-precision geohashes (region, province, and city). More precise geohash posts happen only when you use those channels or location notes.
+### With Private Group Members
 
-## What We DON'T Do
+Private group members receive the group's name, roster, key epoch, and encrypted group traffic needed to participate. Group messages are confidential to devices holding the current group key, subject to the security of those devices and members.
 
-bitchat **never**:
-- Collects personal information
-- Sells or shares your exact GPS location
-- Stores data on servers we operate
-- Sells your data to advertisers or data brokers
-- Uses analytics or telemetry
-- Creates user profiles
-- Requires registration
+### With Nostr Relays and Internet Gateways
 
-## Encryption
+Internet-backed features are optional. When enabled or used:
 
-All private messages use end-to-end encryption:
-- **X25519** for key exchange
-- **AES-256-GCM** for message encryption
-- **Ed25519** for digital signatures
-- **Argon2id** for password-protected rooms
+- Private fallback messages use BitChat's app-specific encrypted envelopes. This format is not NIP-17, NIP-44, or NIP-59 compatible. Relays can observe the recipient public-key tag, event timing and size, and network metadata, but not the message plaintext or stable sender identity.
+- Public location-channel messages, notes, notices, and presence include a geohash tag, event kind, timestamp, and a public key. A geohash reveals an approximate area; finer precision reveals a smaller area.
+- The optional mesh bridge publishes bridge-enabled public mesh messages and presence to a neighborhood rendezvous cell. Those messages are public to participants and relays for that cell. A per-message “nearby only” choice prevents that message from crossing the bridge.
+- Bridge courier drops contain opaque end-to-end encrypted envelopes and a rotating recipient tag. Relays still observe timing and network metadata.
+- A device with gateway features enabled may relay signed bridge/location traffic or opaque courier envelopes for nearby mesh devices.
 
-## Your Rights
+Nostr relays are operated by third parties. Their retention, logging, availability, and privacy practices are outside the project's control. Public events and encrypted events may remain on relays according to each relay's policy.
 
-You have complete control:
-- **Delete Local State**: Triple-tap the logo to instantly wipe local keys, sessions, caches, and preferences
-- **Leave Anytime**: Close the app and local presence stops; relay-backed presence ages out
-- **No Account**: No account record exists for you to delete from us
-- **Portability**: Your local state stays on your device unless you send messages, use optional relay-backed features, or export it
+You can add relays yourself in settings, including `.onion` addresses. Added relays are stored locally, are limited in number, and are erased by panic wipe. Tor routing is on by default; while it is off, every relay you connect to can see your IP address, including relays carrying your private messages.
 
-## Bluetooth & Permissions
+## Location and Apple Services
 
-bitchat requires Bluetooth permission to function:
-- Used only for peer-to-peer communication
-- Bluetooth is not used for tracking
-- You can revoke this permission at any time in system settings
+Location permission is optional and requested as when-in-use access. It is used to compute geohash channels, bridge rendezvous cells, and nearby place labels.
 
-## Location Permission
+- Exact coordinates are not included in bitchat mesh or Nostr payloads and are not persisted by bitchat.
+- A selected geohash can still reveal an approximate area to peers and relays.
+- When bitchat asks the operating system for a friendly place name, Apple's `CLGeocoder` service may process the location under Apple's privacy terms.
+- Revoking location permission stops live location sampling. Saved bookmarks remain until you remove them, panic-wipe the app, or remove the app.
 
-Location permission is optional and is used only for location channels:
-- Used to compute local geohash channels and display names
-- Requested as when-in-use permission
-- Exact coordinates are not shared in messages or stored by bitchat
-- Selected and bookmarked geohashes may persist locally until you remove them, use panic wipe, or delete the app
-- You can revoke this permission at any time in system settings
+## Microphone, Camera, and Media Permissions
+
+- Microphone access is used only while you record a voice note or actively hold live push-to-talk. The resulting audio is sent to the mesh conversation you selected; public-conversation audio is public to that mesh, while private-conversation audio uses the private transport protections described below.
+- Voice-note and live-audio files can remain in Application Support under the media retention rules above.
+- Camera access is used to scan peer-verification QR codes. Photo-library access is used when you choose an image to send.
+- These permissions can be revoked in system settings. bitchat does not record microphone or camera input while the related capture UI is inactive.
+
+## Cryptography
+
+Private and public features use different protections:
+
+- Mesh private sessions use Noise XX with X25519, ChaCha20-Poly1305, and SHA-256.
+- Private group messages use ChaCha20-Poly1305; group state and relevant mesh packets use Ed25519 signatures.
+- Nostr events use secp256k1 Schnorr signatures. BitChat private envelopes use secp256k1 key agreement, HKDF-SHA256, and XChaCha20-Poly1305. The envelope format is proprietary, only interoperates with BitChat clients, and does not provide forward secrecy against later compromise of the recipient's static Nostr private key.
+- The persistent private-message outbox uses ChaCha20-Poly1305 with a key held in the keychain. Some other protected local identity state uses AES-GCM.
+- Public mesh, bridge, geohash, and board content is signed or authenticated as appropriate but is intentionally not confidential.
+
+No cryptographic system can protect content after a recipient reads, copies, screenshots, or exports it.
+
+## Data Retention Summary
+
+- **In-memory chat timelines and active connections:** until the app closes or state is cleared.
+- **Queued outgoing private messages:** until acknowledged, dropped by bounded policy, or 24 hours, whichever comes first.
+- **Opaque courier envelopes:** until handed off, evicted by bounded policy, or 24 hours, whichever comes first.
+- **Recent public mesh gossip:** up to 6 hours.
+- **Public board posts and tombstones:** until expiry, at most seven days.
+- **Media:** seven days, or sooner by quota eviction, panic wipe, or app removal.
+- **Groups, favorites, preferences, identity keys, and bookmarks:** until removed by the feature, panic wipe, or app removal.
+- **Nostr data:** according to the policies of the relays that receive it.
+
+## Your Controls
+
+- **Panic wipe:** Triple-tap the logo to synchronously cancel in-flight media work and clear local keys, sessions, preferences, groups, queues, carried mail, public archives, board data, and media managed by the app.
+- **Notification previews:** Hidden by default, so lock-screen alerts do not show message text, sender names, or geohashes. Full previews can be turned on in settings.
+- **Clearing a conversation:** Clearing the mesh timeline also deletes the recent public gossip this device had stored on disk.
+- **Feature controls:** Location channels, mesh bridge, internet gateway, and related internet behaviors can be disabled in the app. Some already-published relay data cannot be recalled.
+- **System permissions:** Bluetooth, location, microphone, camera, and photo-library access can be revoked in system settings.
+- **No account:** The project operates no account record for you to request or export.
+
+## What the Project Does Not Do
+
+bitchat does not:
+
+- Operate an account database or project-owned messaging backend.
+- Include advertising, analytics, or tracking SDKs.
+- Sell user data or create advertising profiles.
+- Include exact GPS coordinates in bitchat mesh or Nostr message payloads.
 
 ## Children's Privacy
 
-bitchat does not knowingly collect information from children. The app has no age verification because it collects no personal information from anyone.
-
-## Data Retention
-
-- **Messages**: Deleted from memory when app closes (unless room retention is enabled)
-- **Identity Key**: Persists until you delete the app
-- **Favorites**: Persist until you remove them or delete the app
-- **Location channel choices**: Selected/bookmarked geohashes persist locally until removed, panic-wiped, or the app is deleted
-- **Nostr relay data**: Public geohash events and encrypted gift wraps may be retained by relays according to each relay's policy
-- **Everything Else**: Exists only during active sessions
-
-## Security Measures
-
-- All communication is encrypted
-- No accounts or company servers
-- Optional Nostr relays receive only the events needed for Nostr-backed private fallback or public location channels
-- Open source code for public audit
-- Regular security updates
-- Cryptographic signatures prevent tampering
+The project does not knowingly operate a service that collects children's personal data. The app has no account registration or age-verification system. Users and guardians should understand that public mesh, board, bridge, and location-channel posts are visible to other participants and may be relayed.
 
 ## Changes to This Policy
 
-If we update this policy:
-- The "Last updated" date will change
-- The updated policy will be included in the app
-- No retroactive changes can make us collect data already held only in your app
+Material behavior changes will be reflected in this document and its “Last updated” date. Updating this policy cannot retroactively retrieve data that remained only on a user's device.
 
 ## Contact
 
 bitchat is an open source project. For privacy questions:
-- View our source code: [https://github.com/permissionlesstech/bitchat/tree/main](https://github.com/permissionlesstech/bitchat/tree/main)
-- Open an issue on GitHub
-- Join the discussion in public rooms
 
-## Philosophy
-
-Privacy isn't just a feature—it's the entire point. bitchat proves that modern communication doesn't require surrendering your privacy. No accounts, no company servers, no analytics. Just people talking freely.
+- View the source: [https://github.com/permissionlesstech/bitchat](https://github.com/permissionlesstech/bitchat)
+- Open an issue on GitHub.
 
 ---
 
-*This policy is released into the public domain under The Unlicense, just like bitchat itself.*
+*This policy is released into the public domain under The Unlicense, like the project itself.*

Package.swift

@@ -13,9 +13,9 @@ let package = Package(
         .executable(
             name: "bitchat",
             targets: ["bitchat"]
-        ),
+        )
     ],
-    dependencies:[
+    dependencies: [
         .package(path: "localPackages/Arti"),
         .package(path: "localPackages/BitFoundation"),
         .package(path: "localPackages/BitLogger"),
@@ -63,7 +63,11 @@ let package = Package(
                 // Only the vector fixture: declaring the whole "Noise"
                 // directory would claim its .swift test files as resources
                 // and silently drop them from compilation.
-                .process("Noise/NoiseTestVectors.json")
+                .process("Noise/NoiseTestVectors.json"),
+                // Frozen envelopes produced by the released iOS (733098bb)
+                // and Android (b7f0b33d) private-DM implementations; prove
+                // receive compatibility independently of the local generator.
+                .process("Nostr/Fixtures")
             ]
         )
     ]

README.md

@@ -8,6 +8,14 @@ A decentralized peer-to-peer messaging app with dual transport architecture: loc
 
 📲 [App Store](https://apps.apple.com/us/app/bitchat-mesh/id6748219622)
 
+📲 [Play Store](https://play.google.com/store/apps/details?id=com.bitchat.droid)
+
+### Getting a copy you can trust
+
+Install from the App Store, or build from source you have verified. A compiled build from anywhere else cannot be verified — see [Verifying bitchat](docs/VERIFYING-A-BUILD.md) for how to check source against the per-release hash manifest, and for what to do if that is the only build you can get.
+
+This matters more than it usually would: this repository has been the target of takedown demands, and when a repository or releases page disappears, mirrors appear that nobody can check.
+
 ## License
 
 This project is released into the public domain. See the [LICENSE](LICENSE) file for details.
@@ -18,8 +26,8 @@ This project is released into the public domain. See the [LICENSE](LICENSE) file
 - **Location-Based Channels**: Geographic chat rooms using geohash coordinates over global Nostr relays
 - **Intelligent Message Routing**: Automatically chooses best transport (Bluetooth → Nostr fallback)
 - **Decentralized Mesh Network**: Automatic peer discovery and multi-hop message relay over Bluetooth LE
-- **Privacy First**: No accounts, no phone numbers, no persistent identifiers
-- **Private Message End-to-End Encryption**: [Noise Protocol](https://noiseprotocol.org) for mesh, NIP-17 for Nostr
+- **Privacy First**: No accounts, no phone numbers, no servers. Note that the mesh does use a persistent per-device identifier derived from your identity key — see [the whitepaper](WHITEPAPER.md) on identity and metadata for what a nearby radio can observe
+- **Private Message End-to-End Encryption**: [Noise Protocol](https://noiseprotocol.org) for mesh, BitChat private envelopes for Nostr fallback
 - **IRC-Style Commands**: Familiar `/slap`, `/msg`, `/who` style interface
 - **Universal App**: Native support for iOS and macOS
 - **Emergency Wipe**: Triple-tap to instantly clear all data
@@ -34,7 +42,7 @@ BitChat uses a **hybrid messaging architecture** with two complementary transpor
 - **Local Communication**: Direct peer-to-peer within Bluetooth range
 - **Multi-hop Relay**: Messages route through nearby devices (max 7 hops)
 - **No Internet Required**: Works completely offline in disaster scenarios
-- **Noise Protocol Encryption**: End-to-end encryption with forward secrecy
+- **Noise Protocol Encryption**: End-to-end encryption, with forward secrecy for live sessions (store-and-forward mail is sealed without it — see the whitepaper)
 - **Binary Protocol**: Compact packet format optimized for Bluetooth LE constraints
 - **Automatic Discovery**: Peer discovery and connection management
 - **Adaptive Power**: Battery-optimized duty cycling
@@ -43,10 +51,16 @@ BitChat uses a **hybrid messaging architecture** with two complementary transpor
 
 - **Global Reach**: Connect with users worldwide via internet relays
 - **Location Channels**: Geographic chat rooms using geohash coordinates
-- **290+ Relay Network**: Distributed across the globe for reliability
-- **NIP-17 Encryption**: Gift-wrapped private messages for internet privacy
+- **440+ Relay Network**: Distributed across the globe for reliability
+- **BitChat Private Envelopes**: App-specific encrypted private messages over Nostr relays
 - **Ephemeral Keys**: Fresh cryptographic identity per geohash area
 
+BitChat's private-envelope format is proprietary and is **not** NIP-17,
+NIP-44, or NIP-59 compatible. It uses Nostr as a relay transport but only
+interoperates with BitChat clients: private payloads travel inside kind-1059
+events whose `v2:`-prefixed content is a BitChat-specific XChaCha20-Poly1305
+construction, not NIP-44 encryption.
+
 ### Channel Types
 
 #### `mesh #bluetooth`
@@ -80,7 +94,7 @@ Private messages use **intelligent transport selection**:
 2. **Nostr Fallback** (when Bluetooth unavailable)
 
    - Uses recipient's Nostr public key
-   - NIP-17 gift-wrapping for privacy
+   - BitChat's app-specific private-envelope encryption
    - Routes through global relay network
 
 3. **Smart Queuing** (when neither available)
@@ -93,30 +107,62 @@ For detailed protocol documentation, see the [Technical Whitepaper](WHITEPAPER.m
 
 ### Option 1: Using Xcode
 
-   ```bash
-   cd bitchat
-   open bitchat.xcodeproj
-   ```
+```bash
+open bitchat.xcodeproj
+```
 
-   To run on a device there're a few steps to prepare the code:
-   - Clone the local configs: `cp Configs/Local.xcconfig.example Configs/Local.xcconfig`
-   - Add your Developer Team ID into the newly created `Configs/Local.xcconfig`
-      - Bundle ID would be set to `chat.bitchat.<team_id>` (unless you set to something else)
-   - Entitlements need to be updated manually (TODO: Automate):
-      - Search and replace `group.chat.bitchat` with `group.<your_bundle_id>` (e.g. `group.chat.bitchat.ABC123`)
+For a signed device build, create your ignored local configuration and replace
+the example team ID with your Apple Developer Team ID:
+
+```bash
+cp Configs/Local.xcconfig.example Configs/Local.xcconfig
+```
+
+`Local.xcconfig.example` derives unique app and App Group identifiers from that
+team ID. The entitlement files already reference `$(APP_GROUP_ID)`, so tracked
+project or entitlement files do not need to be edited.
+
+Useful command-line checks from the repository root:
+
+```bash
+# macOS Debug build without signing
+xcodebuild -project bitchat.xcodeproj -scheme "bitchat (macOS)" \
+  -configuration Debug CODE_SIGNING_ALLOWED=NO build
+
+# Full SwiftPM test suite
+swift test
+
+# iOS simulator tests
+xcodebuild -project bitchat.xcodeproj -scheme "bitchat (iOS)" \
+  -sdk iphonesimulator \
+  -destination 'platform=iOS Simulator,name=iPhone 17' test
+```
+
+If `iPhone 17` is unavailable, choose an installed simulator from:
+
+```bash
+xcodebuild -showdestinations -project bitchat.xcodeproj -scheme "bitchat (iOS)"
+```
 
 ### Option 2: Using `just`
 
-   ```bash
-   brew install just
-   ```
+```bash
+brew install just
+just check
+just run
+```
 
-Want to try this on macos: `just run` will set it up and run from source.
-Run `just clean` afterwards to restore things to original state for mobile app building and development.
+`just build` and `just run` use the current `bitchat (macOS)` scheme and keep
+Xcode output in the ignored `.DerivedData/` directory. They never patch source,
+project, configuration, or entitlement files.
+
+`just clean` removes only `.DerivedData/` and `.build/`. It does not invoke Git
+or restore tracked files, so uncommitted work is preserved. `just test` runs the
+SwiftPM suite and `just test-ios` runs the iPhone 17 simulator suite.
 
 ## Localization
 
-- Base app resources live under `bitchat/Localization/Base.lproj/`. Add new copy to `Localizable.strings` and plural rules to `Localizable.stringsdict`.
-- Share extension strings are separate in `bitchatShareExtension/Localization/Base.lproj/Localizable.strings`.
+- App localizations live in `bitchat/Localizable.xcstrings`.
+- Share extension strings are separate in `bitchatShareExtension/Localization/Localizable.xcstrings`.
 - Prefer keys that describe intent (`app_info.features.offline.title`) and reuse existing ones where possible.
 - Run `xcodebuild -project bitchat.xcodeproj -scheme "bitchat (macOS)" -configuration Debug CODE_SIGNING_ALLOWED=NO build` to compile-check any localization updates.

SECURITY.md

@@ -0,0 +1,45 @@
+# Security policy
+
+bitchat is a security-focused messenger, and reports about its security are taken seriously. This page says how to report, what counts as a vulnerability here, and what to expect.
+
+## Reporting a vulnerability
+
+**Use GitHub's private vulnerability reporting:** [Report a vulnerability](https://github.com/permissionlesstech/bitchat/security/advisories/new) (Security tab → "Report a vulnerability").
+
+Please do not open a public issue for anything that could put people at risk before a fix ships. bitchat is used by people in hostile network environments; a public proof-of-concept can be acted on faster than a patch can reach them.
+
+A useful report says what an attacker can do, against which build (App Store version or commit hash), and how to reproduce it. A failing test or a packet capture is worth more than speculation about impact.
+
+## What to expect
+
+This is a volunteer-maintained project. The aim is to acknowledge reports within a week and to move on confirmed vulnerabilities immediately — historically, confirmed protocol and key-handling issues have been fixed within days. You'll be kept in the loop in the advisory thread, and credited in the fix unless you'd rather not be. There is no bug bounty.
+
+## Supported versions
+
+Fixes ship to the latest App Store release and `main`. Older releases are not patched; the fix is to update.
+
+## Scope
+
+In scope — the properties the app promises:
+
+- Confidentiality and integrity of private messages and media (Noise sessions over BLE; over Nostr, bitchat's own ephemeral private-envelope format — a proprietary scheme, *not* NIP-17/NIP-44/NIP-59, see `WHITEPAPER.md`)
+- Identity: key handling, verification, impersonation, session binding
+- The panic wipe actually destroying what it claims to destroy
+- Metadata exposure beyond what the documentation already discloses (see `PRIVACY_POLICY.md` and `docs/privacy-assessment.md`)
+- Downgrade paths: anything that silently moves traffic from an encrypted path to a plaintext one
+- Tor routing: anything that makes traffic bypass Tor while the Tor preference is on
+- Supply-chain integrity of the source and its vendored binaries (see `docs/VERIFYING-A-BUILD.md`)
+
+Out of scope — documented design properties, not vulnerabilities:
+
+- Public visibility of mesh announces and geohash channels: broadcast content, nicknames, and public keys are public by design
+- Bluetooth proximity being observable: anyone in radio range can tell a BLE device is present
+- Mesh flooding/relay behavior inherent to a broadcast mesh (rate limits exist; the topology is what it is)
+- Behavior of third-party Nostr relays
+- Denial of service requiring physical proximity, and battery-drain attacks in general
+
+If you're unsure whether something is in scope, report it privately anyway — a false alarm costs a few minutes; a real issue reported publicly can cost much more.
+
+## Verifying what you're running
+
+If your concern is that the app or source you have has been tampered with, that has its own document: `docs/VERIFYING-A-BUILD.md`.

WHITEPAPER.md

@@ -1,309 +1,150 @@
-# BitChat Protocol Whitepaper
+# bitchat Protocol Whitepaper
 
-**Version 1.1**
+**Version 2.0**
 
-**Date: July 25, 2025**
+**Date: July 6, 2026**
 
 ---
 
 ## Abstract
 
-BitChat is a decentralized, peer-to-peer messaging application designed for secure, private, and censorship-resistant communication over ephemeral, ad-hoc networks. This whitepaper details the BitChat Protocol Stack, a layered architecture that combines a modern cryptographic foundation with a flexible application protocol. At its core, BitChat leverages the Noise Protocol Framework (specifically, the `XX` pattern) to establish mutually authenticated, end-to-end encrypted sessions between peers. This document provides a technical specification of the identity management, session lifecycle, message framing, and security considerations that underpin the BitChat network.
+bitchat is a decentralized, peer-to-peer messaging application for secure, private, censorship-resistant communication that works with or without the internet. Nearby devices form an ad-hoc Bluetooth Low Energy (BLE) mesh; distant peers are reached over the Nostr protocol when a connection exists. A layered store-and-forward stack — a persistent sender outbox, opportunistic couriers with a spray-and-wait copy budget, gossip-synced public history, and Nostr relay mailboxes — delivers messages to peers who are out of range at send time. This document describes the protocol and its delivery guarantees as implemented.
 
 ---
 
-## 1. Introduction
+## 1. Design Goals
 
-In an era of centralized communication platforms, BitChat offers a resilient alternative by operating without central servers. It is designed for scenarios where internet connectivity is unavailable or untrustworthy, such as protests, natural disasters, or remote areas. Communication occurs directly between devices over transports like Bluetooth Low Energy (BLE).
+* **Confidentiality:** all private communication is end-to-end encrypted; intermediate nodes and couriers carry only opaque ciphertext.
+* **Authentication:** peers are identified by cryptographic keys; announcements are signed and verified.
+* **Resilience:** the network functions in lossy, low-bandwidth, partitioned environments with churning membership.
+* **Eventual delivery:** a message to an out-of-range peer should still arrive — relayed by the mesh, carried by a moving person, or resting on an internet relay — within a bounded retention window.
+* **Ephemerality by default:** conversation timelines live in memory only. Everything the store-and-forward stack persists is either sealed ciphertext or already-public broadcast traffic, and all of it dies with the panic wipe. Media is the exception: accepted images and voice notes are written to disk unsealed, protected by the platform's data-protection class rather than by app-layer encryption, and bounded by a storage quota.
 
-The design goals of the BitChat Protocol are:
+## 2. Architecture Overview
 
-*   **Confidentiality:** All communication must be unreadable to third parties.
-*   **Authentication:** Users must be able to verify the identity of their correspondents.
-*   **Integrity:** Messages cannot be tampered with in transit.
-*   **Forward Secrecy:** The compromise of long-term identity keys must not compromise past session keys.
-*   **Deniability:** It should be difficult to cryptographically prove that a specific user sent a particular message.
-*   **Resilience:** The protocol must function reliably in lossy, low-bandwidth environments.
+Two transports implement a common `Transport` interface and are coordinated by a `MessageRouter`:
 
-This paper specifies the technical details of the protocol designed to meet these goals.
+* **BLE mesh** — every device is simultaneously a GATT central and peripheral, relaying packets in a controlled flood. No infrastructure, pairing, or accounts.
+* **Nostr** — private messages to mutual favorites travel in BitChat's app-specific encrypted envelopes over public relays (over Tor where enabled), bridging separate meshes through the internet.
 
----
+The router prefers a live mesh link, falls back to Nostr, and engages the courier system when neither can deliver promptly.
 
-## 2. Protocol Stack
+## 3. Identity
 
-The BitChat Protocol is a four-layer stack. This layered approach separates concerns, allowing for modularity and future extensibility.
+Each device holds two long-term key pairs in the Keychain:
 
-```mermaid
-graph TD
-    A[Application Layer] --> B[Session Layer];
-    B --> C[Encryption Layer];
-    C --> D[Transport Layer];
+* a **Curve25519 static key** for Noise key agreement — its SHA-256 fingerprint is the peer's stable identity, and
+* an **Ed25519 signing key** for packet signatures.
 
-    subgraph "BitChat Application"
-        A
-    end
+On the mesh, peers appear under a short 8-byte peer ID. That ID is **not ephemeral**: it is the first 8 bytes of the SHA-256 fingerprint of the device's Noise static key, so it is stable across sessions, reboots, and reinstalls that preserve the keychain, and it changes only when the identity itself is replaced by a panic wipe. Favoriting pins the full Noise public key so identity survives across sessions. Mutual favorites also exchange Nostr public keys for the internet path. Optional QR verification binds a nickname to a fingerprint in person.
 
-    subgraph "Message Framing & State"
-        B
-    end
+Signed announcements additionally carry the nickname, the Noise static public key, and the Ed25519 signing public key in cleartext (§4.5), so a passive receiver in radio range can link a device across time and place regardless of the peer ID. Unlinkable presence is not a property this protocol currently provides; see §9.
 
-    subgraph "Noise Protocol Framework"
-        C
-    end
+## 4. BLE Mesh Layer
 
-    subgraph "BLE, Wi-Fi Direct, etc."
-        D
-    end
+### 4.1 Packet Format
 
-    style A fill:#cde4ff
-    style B fill:#b5d8ff
-    style C fill:#9ac2ff
-    style D fill:#7eadff
-```
+A compact binary header (version, type, TTL, timestamp, flags) is followed by an 8-byte sender ID, an optional 8-byte recipient ID, the payload, and an optional Ed25519 signature. Version 2 packets may carry an explicit source route. Signatures exclude the TTL byte so relays can decrement it without invalidating them.
 
-*   **Application Layer:** Defines the structure of user-facing messages (`BitchatMessage`), acknowledgments (`DeliveryAck`), and other application-level data.
-*   **Session Layer:** Manages the overall communication packet (`BitchatPacket`). This includes routing information (TTL), message typing, fragmentation, and serialization into a compact binary format.
-*   **Encryption Layer:** Establishes and manages secure channels using the Noise Protocol Framework. It is responsible for the cryptographic handshake, session management, and transport message encryption/decryption.
-*   **Transport Layer:** The underlying physical medium used for data transmission, such as Bluetooth Low Energy (BLE). This layer is abstracted away from the core protocol.
+Only `noiseEncrypted` and `noiseHandshake` packets are padded, toward 256/512/1024/2048-byte buckets; every other type — public messages, announcements, board posts, group messages, fragments, files, and voice frames — goes out at its natural length. Padding is PKCS#7-style with pad bytes equal to the pad length, and because that length must fit one byte, a frame needing more than 255 bytes to reach its bucket is emitted unpadded. Payload length is therefore observable for most traffic.
 
----
+### 4.2 Flood Control
 
-## 3. Identity and Key Management
+Relaying is a deterministic controlled flood tuned by local connection degree:
 
-A peer's identity in BitChat is defined by two persistent cryptographic key pairs, which are generated on first launch and stored securely in the device's Keychain.
+* **TTL:** packets originate with TTL 7. Relays clamp: dense graphs (≥ 6 links) cap broadcast TTL at 5; thin chains (≤ 2 links) relay at full incoming depth.
+* **Deduplication:** an LRU seen-set (1000 entries, 5-minute expiry) keyed by sender, timestamp, type, and a payload digest drops duplicates. A scheduled relay is cancelled when a duplicate arrives first from another relay.
+* **Jitter:** relays wait a random 10–220 ms (wider when dense) so duplicate suppression wins often.
+* **Fanout subsetting:** broadcast messages are re-sent to a deterministic, message-ID-seeded subset of links (~log₂ of degree) rather than all of them; announces, fragments, and sync packets use full fanout. The ingress link is always excluded (split horizon).
+* **Directed traffic** (handshakes, private messages, courier envelopes) relays deterministically with TTL − 1 and tight jitter, and is never subset.
 
-1.  **Noise Static Key Pair (`Curve25519`):** This is the long-term identity key used for the Noise Protocol handshake. The public part of this key is shared with peers to establish secure sessions.
-2.  **Signing Key Pair (`Ed25519`):** This key is used to sign announcements and other protocol messages where non-repudiation is required, such as binding a public key to a nickname.
+### 4.3 Routing
 
-### 3.1. Fingerprint
+Announcements carry up to 10 direct-neighbor IDs, giving each node a shallow topology map (60 s freshness). When a bidirectionally-confirmed path exists, packets are source-routed along it; otherwise — and whenever a route fails — delivery falls back to flooding.
 
-A user's unique, verifiable fingerprint is the **SHA-256 hash** of their **Noise static public key**. This provides a user-friendly and secure way to verify an identity out-of-band (e.g., by reading it aloud or scanning a QR code).
+### 4.4 Fragmentation
 
-`Fingerprint = SHA256(StaticPublicKey_Curve25519)`
+Packets exceeding the link MTU split into ~469-byte fragments (8-byte fragment ID, index/total header) that relay independently and reassemble at each receiving node (128 concurrent assemblies, 30 s timeout, 1 MiB cap).
 
-### 3.2. Identity Management
+### 4.5 Presence
 
-The `SecureIdentityStateManager` class is responsible for managing all cryptographic identity material and social metadata (petnames, trust levels, etc.). It uses an in-memory cache for performance and persists this cache to the Keychain after encrypting it with a separate AES-GCM key.
+Signed announcements propagate multi-hop: every 4 s while isolated, backing off to ~15–30 s (jittered) when connected. A verified announce retains a peer as *reachable* for 60 s after last contact. Connection scheduling is RSSI-gated with duty-cycled scanning to bound battery drain.
 
----
+## 5. Encryption
 
-## 4. The Social Trust Layer
+### 5.1 Live Sessions: Noise XX
 
-Beyond cryptographic identity, BitChat incorporates a social trust layer, allowing users to manage their relationships with peers. This functionality is handled by the `SecureIdentityStateManager`.
+Connected peers establish sessions with the Noise `XX` pattern (Curve25519 / ChaCha20-Poly1305 / SHA-256), providing mutual authentication and forward secrecy. All private payloads — messages, delivery acks, read receipts — ride inside the session as typed ciphertext. Intermediate relays see only opaque `noiseEncrypted` packets.
 
-### 4.1. Peer Verification
+### 5.2 Offline Seals: Noise X
 
-While the Noise handshake cryptographically authenticates a peer's key, it doesn't confirm the real-world identity of the person holding the device. To solve this, users can perform out-of-band (OOB) verification by comparing fingerprints. Once a user confirms that a peer's fingerprint matches the one they expect, they can mark that peer as "verified". This status is stored locally and displayed in the UI, providing a strong assurance of identity for future conversations.
+Courier envelopes are sealed to the recipient's *static* key with the one-way Noise `X` pattern; the sender's identity is authenticated inside the ciphertext. **This path has no forward secrecy** — compromise of the recipient's static key exposes sealed-but-undelivered mail. A prekey scheme is future work.
 
-### 4.2. Favorites and Blocking
+### 5.3 Nostr Path
 
-To improve the user experience and provide control over interactions, the protocol supports:
-*   **Favorites:** Users can mark trusted or frequently contacted peers as "favorites". This is a local designation that can be used by the application to prioritize notifications or display peers more prominently.
-*   **Blocking:** Users can block peers. When a peer is blocked, the application will discard any incoming packets from that peer's fingerprint at the earliest possible stage, effectively silencing them without notifying the blocked peer.
+Private messages to mutual favorites use BitChat's proprietary private-envelope protocol. An unsigned inner message (kind 14) is encrypted and placed in a sender-signed seal (kind 13); that seal is encrypted again inside a public envelope (kind 1059) signed by a one-time key, so relays learn neither the stable sender identity nor the content. Each encrypted content field is `v2:` followed by base64url of a 24-byte nonce, XChaCha20-Poly1305 ciphertext, and its 16-byte tag. Keys come from secp256k1 ECDH and HKDF-SHA256 (the derivation reuses a "nip44-v2" info label but is not the NIP-44 key schedule).
 
----
+This format reuses NIP-17/NIP-59 kind numbers but is **not NIP-17, NIP-44, or NIP-59 compatible** and interoperates only with BitChat clients. The outer `p` tag exposes the recipient's Nostr public key to relays; the plaintext and stable sender identity remain inside authenticated ciphertext. Public seal and envelope timestamps are randomized by up to ±15 minutes, while the actual message timestamp is encrypted. The protocol does not provide forward secrecy: compromise of the recipient's static Nostr private key can expose stored envelopes addressed to that key.
 
-## 5. The Noise Protocol Layer
+## 6. Store and Forward
 
-BitChat implements the Noise Protocol Framework to provide strong, authenticated end-to-end encryption.
+Four mechanisms cover the "recipient is not here right now" problem. All persisted state is wiped by panic mode.
 
-### 5.1. Protocol Name
+### 6.1 Sender Outbox
 
-The specific Noise protocol implemented is:
+Private messages without a prompt route are retained per peer (100 messages/peer, 24 h TTL) and re-sent on reconnect events until a delivery or read ack clears them, or a resend cap (8 attempts) drops them with visible failure. The outbox persists to disk sealed under a ChaChaPoly key held only in the Keychain, so queued mail survives an app kill without ever storing plaintext.
 
-**`Noise_XX_25519_ChaChaPoly_SHA256`**
+### 6.2 Couriers
 
-*   **`XX` Pattern:** This handshake pattern provides mutual authentication and forward secrecy. It does not require either party to know the other's static public key before the handshake begins. The keys are exchanged and authenticated during the three-part handshake. This is ideal for a decentralized P2P environment.
-*   **`25519`:** The Diffie-Hellman function used is Curve25519.
-*   **`ChaChaPoly`:** The AEAD (Authenticated Encryption with Associated Data) cipher is ChaCha20-Poly1305.
-*   **`SHA256`:** The hash function used for all cryptographic hashing operations is SHA-256.
+When no transport can deliver promptly, the message is sealed (§5.2) into a **courier envelope** and handed to up to 3 connected peers who may physically encounter the recipient:
 
-### 5.2. The `XX` Handshake
+* **Opaque addressing.** The only routing information is a 16-byte rotating recipient tag — an HMAC of the recipient's static key and the UTC day — computable solely by parties who already know that key. Couriers learn neither sender, recipient, nor content, and tags do not correlate across days.
+* **Trust tiers.** Mutual favorites may deposit 5 envelopes each; any peer with a signature-verified announce may deposit 2, into a bounded pool (20 of 40 slots) that can never crowd out favorites' mail. Envelopes are capped at 16 KiB and 24 h; overflow evicts oldest verified-tier mail first.
+* **Deposit retry.** Queued messages are re-deposited whenever a new eligible courier connects, until 3 distinct couriers carry the message or it expires.
+* **Spray and wait.** Envelopes carry a copy budget (initially 4, capped at 8). A courier meeting another eligible courier hands over half its remaining budget, so mail diffuses through a moving crowd instead of riding one person. Budgets, spray history, and carried mail persist across app restarts (iOS file protection).
+* **Handover.** On a verified *direct* announce from the recipient, matching envelopes are delivered over the live link and removed. On a verified *relayed* announce, a copy floods toward the recipient as a directed packet while the carried original stays put, throttled to one attempt per envelope per 10 minutes.
+* Receivers dedup by message ID, so redundant copies and the retained outbox original are harmless. Couriered mail from blocked senders is dropped at decryption time.
 
-The `XX` handshake consists of three messages exchanged between an Initiator and a Responder to establish a shared secret and derive transport encryption keys.
+### 6.3 Public History (Gossip Sync)
 
-```mermaid
-sequenceDiagram
-    participant I as Initiator
-    participant R as Responder
+Public broadcast messages are cached (1000 packets) and reconciled between peers every ~15 s using compact GCS filters: each side advertises what it holds, the other returns what is missing. Messages stay sync-able for **6 hours** and the cache persists to disk, so a device that walks between two partitions — or relaunches later — serves the room's recent history to whoever missed it. Fragments and file transfers keep a short 15-minute window.
 
-    Note over I, R: Pre-computation: h = SHA256(protocol_name)
+### 6.4 Nostr Mailboxes
 
-    I->>R: -> e
-    Note right of I: I generates ephemeral key `e_i`.<br/>h = SHA256(h + e_i.pub)
+BitChat private envelopes rest on Nostr relays; clients re-subscribe with a 24-hour lookback on reconnect, covering the both-devices-offline case for mutual favorites whenever either side touches the internet.
 
-    R->>I: <- e, ee, s, es
-    Note left of R: R generates ephemeral key `e_r`.<br/>h = SHA256(h + e_r.pub)<br/>MixKey(DH(e_i, e_r))<br/>R sends static key `s_r`, encrypted.<br/>h = SHA256(h + ciphertext)<br/>MixKey(DH(e_i, s_r))
+### 6.5 Delivery Metrics
 
-    I->>R: -> s, se
-    Note right of I: I decrypts and verifies `s_r`.<br/>I sends static key `s_i`, encrypted.<br/>h = SHA256(h + ciphertext)<br/>MixKey(DH(s_i, e_r))
+Bare local counters (deposits, handovers, sprays, opens, outbox flushes and drops — no identities, message IDs, or timestamps) let delivery behavior be measured on-device. They never leave the device and are cleared by the panic wipe.
 
-    Note over I, R: Handshake complete. Transport keys derived.
-```
+## 7. Application Layer
 
-**Handshake Flow:**
-
-1.  **Initiator -> Responder:** The initiator generates a new ephemeral key pair (`e_i`) and sends the public part to the responder.
-2.  **Responder -> Initiator:** The responder receives the initiator's ephemeral public key. It then generates its own ephemeral key pair (`e_r`), performs a DH exchange with the initiator's ephemeral key (`ee`), sends its own static public key (`s_r`) encrypted with the resulting symmetric key, and performs another DH exchange between the initiator's ephemeral key and its own static key (`es`).
-3.  **Initiator -> Responder:** The initiator receives the responder's message, decrypts the responder's static key, and authenticates it. The initiator then sends its own static key (`s_i`) encrypted and performs a final DH exchange between its static key and the responder's ephemeral key (`se`).
-
-Upon completion, both parties share a set of symmetric keys for bidirectional transport message encryption. The final handshake hash is used for channel binding.
-
-### 5.3. Session Management
-
-The `NoiseSessionManager` class manages all active Noise sessions. It handles:
-*   Creating sessions for new peers.
-*   Coordinating the handshake process to prevent race conditions.
-*   Storing the resulting transport ciphers (`sendCipher`, `receiveCipher`).
-*   Periodically checking if sessions need to be re-keyed for enhanced security.
-
----
-
-## 6. The BitChat Session and Application Protocol
-
-Once a Noise session is established, peers exchange `BitchatPacket` structures, which are encrypted as the payload of Noise transport messages.
-
-### 6.1. Binary Packet Format (`BitchatPacket`)
-
-To minimize bandwidth, `BitchatPacket`s are serialized into a compact binary format. The structure is designed to be fixed-size where possible to resist traffic analysis.
-
-| Field           | Size (bytes) | Description                                                                                             |
-|-----------------|--------------|---------------------------------------------------------------------------------------------------------|
-| **Header**      | **13**       | **Fixed-size header**                                                                                   |
-| Version         | 1            | Protocol version (currently `1`).                                                                       |
-| Type            | 1            | Message type (e.g., `message`, `deliveryAck`, `noiseHandshakeInit`). See `MessageType` enum.            |
-| TTL             | 1            | Time-To-Live for mesh network routing. Decremented at each hop.                                         |
-| Timestamp       | 8            | `UInt64` millisecond timestamp of packet creation.                                                      |
-| Flags           | 1            | Bitmask for optional fields (`hasRecipient`, `hasSignature`, `isCompressed`).                           |
-| Payload Length  | 2            | `UInt16` length of the payload field.                                                                   |
-| **Variable**    | **...**      | **Variable-size fields**                                                                                |
-| Sender ID       | 8            | 8-byte truncated peer ID of the sender.                                                                 |
-| Recipient ID    | 8 (optional) | 8-byte truncated peer ID of the recipient. Present if `hasRecipient` flag is set. Broadcast if `0xFF..FF`. |
-| Payload         | Variable     | The actual content of the packet, as defined by the `Type` field.                                       |
-| Signature       | 64 (optional)| `Ed25519` signature of the packet. Present if `hasSignature` flag is set.                               |
-
-**Padding:** All packets are padded to the next standard block size (256, 512, 1024, or 2048 bytes) using a PKCS#7-style scheme to obscure the true message length from network observers.
-
-```mermaid
----
-config:
-  theme: dark
----
----
-title: "BitchatPacket"
----
-packet
-+8: "Version"
-+8: "Type"
-+8: "TTL"
-+64: "Timestamp"
-+8: "Flags"
-+16: "Payload Length"
-+64: "Sender ID"
-+64: "Recipient ID (optional)"
-+48: "Payload (variable)"
-+64: "Signature (optional)"
-```
-_A representation of the sizes of the fields in `BitchatPacket`_
-
-### 6.2. Application Message Format (`BitchatMessage`)
-
-For packets of type `message`, the payload is a binary-serialized `BitchatMessage` containing the chat content.
-
-| Field               | Size (bytes) | Description                                                              |
-|---------------------|--------------|--------------------------------------------------------------------------|
-| Flags               | 1            | Bitmask for optional fields (`isRelay`, `isPrivate`, `hasOriginalSender`). |
-| Timestamp           | 8            | `UInt64` millisecond timestamp of message creation.                      |
-| ID                  | 1 + len      | `UUID` string for the message.                                           |
-| Sender              | 1 + len      | Nickname of the sender.                                                  |
-| Content             | 2 + len      | The UTF-8 encoded message content.                                       |
-| Original Sender     | 1 + len (opt)| Nickname of the original sender if the message is a relay.               |
-| Recipient Nickname  | 1 + len (opt)| Nickname of the recipient for private messages.                          |
-
-```mermaid
----
-config:
-  theme: dark
----
----
-title: "BitchatMessage"
----
-packet
-+8: "Flags"
-+64: "Timestamp"
-+24: "ID (variable)"
-+32: "Sender (variable)"
-+32: "Content (variable)"
-+32: "Original Sender (variable) (optional)"
-+32: "Recipient Nickname (variable) (optional)"
-```
-_A representation of the sizes of the fields in `BitchatMessage`_
-
----
-
-## 7. Message Routing and Propagation
-
-BitChat operates as a decentralized mesh network, meaning there are no central servers to route messages. Packets are propagated through the network from peer to peer. The protocol supports several modes of message delivery.
-
-### 7.1. Direct Connection
-
-This is the simplest case. If Peer A and Peer B are directly connected, they can exchange packets after establishing a mutually authenticated Noise session. All packets are encrypted using the transport ciphers derived from the handshake.
-
-### 7.2. Efficient Gossip with Bloom Filters
-
-To send messages to peers that are not directly connected, BitChat employs a "flooding" or "gossip" protocol. When a peer receives a packet that is not destined for it, it acts as a relay. To prevent infinite routing loops and minimize memory usage, the protocol uses an `OptimizedBloomFilter` to track recently seen packet IDs.
-
-The logic is as follows:
-
-1.  A peer receives a packet.
-2.  It checks the Bloom filter to see if the packet's ID has likely been seen before. If so, the packet is discarded. Bloom filters can have false positives (though they are rare), but they guarantee no false negatives. This means that while some packets may be incorrectly discarded due to false positives, the gossip protocol's redundancy ensures these packets will eventually be received through subsequent exchanges with other peers.
-3.  If the packet is new, its ID is added to the Bloom filter.
-4.  The peer decrements the packet's Time-To-Live (TTL) field.
-5.  If the TTL is greater than zero, the peer re-broadcasts the packet to all of its connected peers, *except* for the peer from which it received the packet.
-
-This mechanism allows packets to "flood" through the network efficiently, maximizing the chance of reaching their destination while using minimal resources to prevent loops.
-
-### 7.3. Time-To-Live (TTL)
-
-Every `BitchatPacket` contains an 8-bit TTL field. This value is set by the originating peer and is decremented by one at each relay hop. If a peer receives a packet and decrements its TTL to 0, it will process the packet (if it is the recipient) but will not relay it further. This is a crucial mechanism to prevent packets from circulating endlessly in the mesh.
-
-### 7.4. Private vs. Broadcast Messages
-
-The routing logic respects the confidentiality of private messages:
-
-*   **Private Messages:** A packet with a specific `recipientID` is a private message. Relay nodes forward the entire, encrypted Noise message without being able to access the inner `BitchatPacket` or its payload. Only the final recipient, who shares the correct Noise session keys with the sender, can decrypt the packet.
-*   **Broadcast Messages:** A packet with the special broadcast `recipientID` (`0xFFFFFFFFFFFFFFFF`) is intended for all peers. Any peer that receives and decrypts a broadcast message will process its content. It will still be relayed according to the flooding algorithm to ensure it reaches the entire network.
-
-### 7.5. Message Reliability and Lifecycle
-
-To function in unreliable, lossy networks, the protocol includes features to track the lifecycle of a message and ensure its delivery.
-
-*   **Delivery Acknowledgments (`DeliveryAck`):** When a private message reaches its final destination, the recipient's device sends a `DeliveryAck` packet back to the original sender. This acknowledgment contains the ID of the original message.
-*   **Read Receipts (`ReadReceipt`):** After a message is displayed on the recipient's screen, the application can send a `ReadReceipt`, also containing the original message ID, to inform the sender that the message has been seen.
-*   **Message Retry Service:** Senders maintain a `MessageRetryService` which tracks outgoing messages. If a `DeliveryAck` is not received for a message within a certain time window, the service will automatically re-send the message, creating a more resilient user experience.
-
-### 7.6. Fragmentation
-
-Transport layers like BLE have a Maximum Transmission Unit (MTU) that limits the size of a single packet. To handle messages larger than this limit, BitChat implements a fragmentation protocol.
-
-*   **`fragmentStart`:** A packet with this type marks the beginning of a fragmented message. It contains metadata about the total size and number of fragments.
-*   **`fragmentContinue`:** These packets carry the intermediate chunks of the message data.
-*   **`fragmentEnd`:** This packet carries the final chunk of the message and signals the receiver to begin reassembly.
-
-Receiving peers collect all fragments and reassemble them in the correct order before passing the complete message up to the application layer.
-
----
+* **Public chat** — signed broadcast messages within the mesh, backed by the gossip-synced history above.
+* **Private chat** — end-to-end encrypted messages with delivery and read receipts, over mesh, courier, or Nostr.
+* **Location channels** — geohash-scoped public rooms carried over Nostr relays for regional chat beyond radio range.
+* **Favorites** — the mutual-trust relationship that unlocks Nostr delivery and the larger courier quota.
+* **Media** — files and images fragment over the mesh (1 MiB cap, explicit accept before anything touches disk); couriers carry text only.
+* **Panic wipe** — clears identity keys, favorites, carried courier mail, the sealed outbox, archived public history, and metrics.
 
 ## 8. Security Considerations
 
-*   **Replay Attacks:** The Noise transport messages include a nonce that is incremented for each message. The `NoiseCipherState` implements a sliding window replay protection mechanism to detect and discard replayed or out-of-order messages.
-*   **Denial of Service:** The `NoiseRateLimiter` is implemented to prevent resource exhaustion from rapid, repeated handshake attempts from a single peer.
-*   **Key-Compromise Impersonation:** The `XX` pattern authenticates both parties, preventing an attacker from impersonating one party to the other.
-*   **Identity Binding:** While the Noise handshake authenticates the cryptographic keys, binding those keys to a human-readable nickname is handled at the application layer. Users must verify fingerprints out-of-band to prevent man-in-the-middle attacks.
-*   **Traffic Analysis:** The use of fixed-size padding for all packets helps to obscure the exact nature and content of the communication, making it harder for a network-level adversary to infer information based on message size.
+* **Relay nodes** cannot read private traffic; they forward opaque ciphertext. Padding applies to Noise frames only (§4.1), so other packet types relay at their natural length.
+* **Couriers** are quota-bounded mailbags. A malicious courier can drop mail (redundant copies and deposit retry mitigate this) but cannot read it, link it across days, or amplify it — copy budgets are capped and every envelope is validated against size and lifetime policy on deposit.
+* **Flooding abuse** is bounded by TTL clamps, deduplication, per-depositor quotas, connect-rate limits, and announce-rate limiting.
+* **Replay** of public broadcasts is bounded by the 6-hour acceptance window plus deduplication; private payloads are protected by Noise nonces.
+* **Metadata is the weakest part of this design, and the peer ID does not help.** The 8-byte sender ID in every packet header is derived from a never-rotating key (§3), and announcements publish the static keys and nickname in cleartext, so a passive listener can enumerate participants and follow a device between places. Announcements also carry up to ten direct-neighbor IDs (§4.3), which hands a single sniffer the local adjacency graph. Origin packets leave at the default TTL, so hop distance identifies the originator. Daily-rotating courier tags do limit correlation of carried mail, and Nostr traffic can ride Tor. Addressing the radio-layer exposure is future work (§9).
+* **No forward secrecy for sealed mail or Nostr private envelopes** (§5.2–5.3) means compromise of a recipient's static key can expose retained ciphertext addressed to that key.
+
+## 9. Future Work
+
+* Prekey-based forward secrecy for courier envelopes.
+* Couriered media beyond the 16 KiB text cap.
+* Probabilistic relay and edge-of-network TTL boosting for very dense and very sparse graphs.
+* Multi-hop courier routing informed by encounter history.
+* **Rotating on-air identity.** Epoch-rotating peer IDs, with static-key disclosure moved inside the encrypted handshake and mutual favorites recognising each other through a tag derived from their shared secret, so presence stops being linkable across sessions (§3, §8).
+* **Padding for non-Noise packet types**, and closing the gap where a frame needing more than 255 bytes of padding is emitted unpadded (§4.1).
+* Making the neighbor list in announcements optional, or restricted to authenticated links (§4.3).
 
 ---
 
-## 9. Conclusion
-
-The BitChat Protocol provides a robust and secure foundation for decentralized, peer-to-peer communication. By layering a flexible application protocol on top of the well-regarded Noise Protocol Framework, it achieves strong confidentiality, authentication, and forward secrecy. The use of a compact binary format and thoughtful security considerations like rate limiting and traffic analysis resistance make it suitable for use in challenging network environments.
+*This document describes the protocol as implemented in the current release. The implementation is free and unencumbered software released into the public domain.*

bitchat.xcodeproj/project.pbxproj

@@ -70,6 +70,7 @@
 		A6E32D1B2E762EA70032EA8A /* Exceptions for "bitchat" folder in "bitchatShareExtension" target */ = {
 			isa = PBXFileSystemSynchronizedBuildFileExceptionSet;
 			membershipExceptions = (
+				Services/SharedContentHandoff.swift,
 				Services/TransportConfig.swift,
 			);
 			target = 57CA17A36A2532A6CFF367BB /* bitchatShareExtension */;
@@ -92,7 +93,7 @@
 		A6E32D232E762EAB0032EA8A /* Exceptions for "bitchatShareExtension" folder in "bitchatShareExtension" target */ = {
 			isa = PBXFileSystemSynchronizedBuildFileExceptionSet;
 			membershipExceptions = (
-				ShareViewController.swift,
+				Info.plist,
 			);
 			target = 57CA17A36A2532A6CFF367BB /* bitchatShareExtension */;
 		};
@@ -258,9 +259,13 @@
 			buildConfigurationList = E4EA6DC648DF55FF84032EB5 /* Build configuration list for PBXNativeTarget "bitchatShareExtension" */;
 			buildPhases = (
 				0A08E70F08F55FD5BA8C7EF3 /* Sources */,
+				7E9B64F63F93443FB7BA12DF /* Resources */,
 			);
 			buildRules = (
 			);
+			fileSystemSynchronizedGroups = (
+				A6E32D212E762EAB0032EA8A /* bitchatShareExtension */,
+			);
 			name = bitchatShareExtension;
 			productName = bitchatShareExtension;
 			productReference = 61F92EBA29C47C0FCC482F1F /* bitchatShareExtension.appex */;
@@ -332,6 +337,7 @@
 				es,
 				ar,
 				de,
+				fa,
 				fr,
 				he,
 				id,
@@ -372,6 +378,11 @@
 				E0A1B2C3D4E5F6012345678D /* relays/online_relays_gps.csv in Resources */,
 			);
 		};
+		7E9B64F63F93443FB7BA12DF /* Resources */ = {
+			isa = PBXResourcesBuildPhase;
+			files = (
+			);
+		};
 		C5E027A42ECCDFD700BD6012 /* Resources */ = {
 			isa = PBXResourcesBuildPhase;
 			files = (
@@ -528,7 +539,6 @@
 					"@executable_path/Frameworks",
 					"@executable_path/../../Frameworks",
 				);
-				MARKETING_VERSION = "$(MARKETING_VERSION)";
 				PRODUCT_BUNDLE_IDENTIFIER = "$(PRODUCT_BUNDLE_IDENTIFIER).ShareExtension";
 				SDKROOT = iphoneos;
 				SUPPORTED_PLATFORMS = "iphoneos iphonesimulator";
@@ -561,7 +571,6 @@
 					"$(inherited)",
 					"@executable_path/Frameworks",
 				);
-				MARKETING_VERSION = 1.5.2;
 				PRODUCT_BUNDLE_IDENTIFIER = "$(PRODUCT_BUNDLE_IDENTIFIER)";
 				PRODUCT_NAME = bitchat;
 				SDKROOT = iphoneos;
@@ -620,7 +629,6 @@
 					"$(inherited)",
 					"@executable_path/Frameworks",
 				);
-				MARKETING_VERSION = 1.5.2;
 				PRODUCT_BUNDLE_IDENTIFIER = "$(PRODUCT_BUNDLE_IDENTIFIER)";
 				PRODUCT_NAME = bitchat;
 				SDKROOT = iphoneos;
@@ -655,7 +663,6 @@
 					"@executable_path/../Frameworks",
 				);
 				MACOSX_DEPLOYMENT_TARGET = "$(MACOSX_DEPLOYMENT_TARGET)";
-				MARKETING_VERSION = 1.5.2;
 				PRODUCT_BUNDLE_IDENTIFIER = "$(PRODUCT_BUNDLE_IDENTIFIER)";
 				PRODUCT_NAME = bitchat;
 				REGISTER_APP_GROUPS = YES;
@@ -716,7 +723,6 @@
 				GCC_WARN_UNUSED_VARIABLE = YES;
 				IPHONEOS_DEPLOYMENT_TARGET = "$(IPHONEOS_DEPLOYMENT_TARGET)";
 				MACOSX_DEPLOYMENT_TARGET = "$(MACOSX_DEPLOYMENT_TARGET)";
-				MARKETING_VERSION = "$(MARKETING_VERSION)";
 				MTL_ENABLE_DEBUG_INFO = NO;
 				MTL_FAST_MATH = YES;
 				PRODUCT_NAME = "$(TARGET_NAME)";
@@ -749,7 +755,6 @@
 					"@executable_path/../Frameworks",
 				);
 				MACOSX_DEPLOYMENT_TARGET = "$(MACOSX_DEPLOYMENT_TARGET)";
-				MARKETING_VERSION = 1.5.2;
 				PRODUCT_BUNDLE_IDENTIFIER = "$(PRODUCT_BUNDLE_IDENTIFIER)";
 				PRODUCT_NAME = bitchat;
 				REGISTER_APP_GROUPS = YES;
@@ -816,7 +821,6 @@
 				GCC_WARN_UNUSED_VARIABLE = YES;
 				IPHONEOS_DEPLOYMENT_TARGET = "$(IPHONEOS_DEPLOYMENT_TARGET)";
 				MACOSX_DEPLOYMENT_TARGET = "$(MACOSX_DEPLOYMENT_TARGET)";
-				MARKETING_VERSION = "$(MARKETING_VERSION)";
 				MTL_ENABLE_DEBUG_INFO = INCLUDE_SOURCE;
 				MTL_FAST_MATH = YES;
 				ONLY_ACTIVE_ARCH = YES;
@@ -846,7 +850,6 @@
 					"@executable_path/Frameworks",
 					"@executable_path/../../Frameworks",
 				);
-				MARKETING_VERSION = "$(MARKETING_VERSION)";
 				PRODUCT_BUNDLE_IDENTIFIER = "$(PRODUCT_BUNDLE_IDENTIFIER).ShareExtension";
 				SDKROOT = iphoneos;
 				SUPPORTED_PLATFORMS = "iphoneos iphonesimulator";

bitchat/App/AppArchitecture.swift

@@ -2,11 +2,6 @@ import BitFoundation
 import Combine
 import Foundation
 
-enum SharedContentKind: String, Sendable, Equatable {
-    case text
-    case url
-}
-
 enum RuntimeScenePhase: String, Sendable, Equatable {
     case active
     case inactive
@@ -18,6 +13,8 @@ enum TorLifecycleEvent: String, Sendable, Equatable {
     case willRestart
     case didBecomeReady
     case preferenceChanged
+    /// Bootstrap ran out its deadline without completing.
+    case bootstrapDidStall
 }
 
 enum AppEvent: Sendable, Equatable {
@@ -25,7 +22,7 @@ enum AppEvent: Sendable, Equatable {
     case startupCompleted
     case scenePhaseChanged(RuntimeScenePhase)
     case openedURL(String)
-    case sharedContentAccepted(SharedContentKind)
+    case sharedContentReadyForReview(SharedContentKind)
     case notificationOpened(peerID: PeerID?)
     case deepLinkOpened(String)
     case torLifecycleChanged(TorLifecycleEvent)
@@ -36,34 +33,12 @@ enum AppEvent: Sendable, Equatable {
 actor AppEventStream {
     private var continuations: [UUID: AsyncStream<AppEvent>.Continuation] = [:]
 
-    func stream() -> AsyncStream<AppEvent> {
-        let id = UUID()
-        return AsyncStream { continuation in
-            continuations[id] = continuation
-            continuation.onTermination = { [id] _ in
-                Task {
-                    await self.removeContinuation(id)
-                }
-            }
-        }
-    }
-
     func emit(_ event: AppEvent) {
         for continuation in continuations.values {
             continuation.yield(event)
         }
     }
 
-    func finish() {
-        for continuation in continuations.values {
-            continuation.finish()
-        }
-        continuations.removeAll()
-    }
-
-    private func removeContinuation(_ id: UUID) {
-        continuations.removeValue(forKey: id)
-    }
 }
 
 /// Identity key for a direct conversation. Equality and hashing use the

bitchat/App/AppChromeModel.swift

@@ -10,16 +10,41 @@ final class AppChromeModel: ObservableObject {
     @Published var showingFingerprintFor: PeerID?
     @Published var isAppInfoPresented = false
     @Published var isLocationChannelsSheetPresented = false
+    @Published var isNoticesSheetPresented = false
+    /// When the sheet is opened for "notes left here" (empty mesh timeline),
+    /// it should land on the geo tab instead of the channel-derived default.
+    @Published var noticesSheetPrefersGeoTab = false
     @Published var showBluetoothAlert = false
     @Published var bluetoothAlertMessage = ""
     @Published var bluetoothState: CBManagerState = .unknown
+    /// Tor bootstrap has stalled (network likely blocks it); drives the
+    /// connectivity banner. Mirrored from `ChatViewModel.torBlocked`.
+    @Published private(set) var torBlocked = false
     @Published var showScreenshotPrivacyWarning = false
+    /// Triple-tapping the logo asks first; the dialog lives on the header.
+    @Published var showPanicConfirmation = false
+    /// Mirrors `ChatViewModel.panicRecoveryBlocked` for the chrome: a wipe
+    /// that did not commit must be visible, not just logged — the person who
+    /// triggered it needs to know data may remain on the device.
+    @Published private(set) var panicWipeBlocked = false
 
     private let chatViewModel: ChatViewModel
+    private let onPanicWipe: () -> Void
     private var cancellables = Set<AnyCancellable>()
+    /// The composer owns capture state above ChatViewModel. ContentView
+    /// installs this hook so both panic entry points synchronously stop it.
+    private var prepareForPanic: (@MainActor () -> Void)?
 
-    init(chatViewModel: ChatViewModel, privateInboxModel: PrivateInboxModel) {
+    /// Bulletin-board coordinator, created on first use of the board sheet.
+    private(set) lazy var boardManager = BoardManager(transport: chatViewModel.meshService)
+
+    init(
+        chatViewModel: ChatViewModel,
+        privateInboxModel: PrivateInboxModel,
+        onPanicWipe: @escaping () -> Void = {}
+    ) {
         self.chatViewModel = chatViewModel
+        self.onPanicWipe = onPanicWipe
         self.nickname = chatViewModel.nickname
 
         bind(privateInboxModel: privateInboxModel)
@@ -59,11 +84,62 @@ final class AppChromeModel: ObservableObject {
         isAppInfoPresented = true
     }
 
+    func presentNotices(geoTab: Bool = false) {
+        noticesSheetPrefersGeoTab = geoTab
+        isNoticesSheetPresented = true
+    }
+
+    /// Builds the mesh topology map model from the transport's gossiped
+    /// graph plus the live nickname table. Unknown nodes (heard about via a
+    /// neighbor claim but never announced to us) fall back to a short ID.
+    func meshTopologyDisplayModel() -> MeshTopologyDisplayModel {
+        let mesh = chatViewModel.meshService
+        guard let diagnostics = mesh as? MeshDiagnosing,
+              let snapshot = diagnostics.currentMeshTopology() else { return .empty }
+        let nicknames = mesh.getPeerNicknames()
+
+        let nodes = snapshot.nodes.map { peerID -> MeshTopologyDisplayModel.Node in
+            let isSelf = peerID == snapshot.localPeerID
+            let label: String
+            if isSelf {
+                label = chatViewModel.nickname
+            } else {
+                label = nicknames[peerID] ?? "\(peerID.id.prefix(8))…"
+            }
+            return MeshTopologyDisplayModel.Node(id: peerID.id, label: label, isSelf: isSelf)
+        }
+        let edges = snapshot.edges.map { ($0.a.id, $0.b.id) }
+        return MeshTopologyDisplayModel(nodes: nodes, edges: edges)
+    }
+
     func triggerScreenshotPrivacyWarning() {
         showScreenshotPrivacyWarning = true
     }
 
+    func setPanicPreparation(_ preparation: (@MainActor () -> Void)?) {
+        prepareForPanic = preparation
+    }
+
+    /// Entry point for the header triple-tap: confirm before destroying.
+    /// The Settings-pane button has always confirmed; the gesture now goes
+    /// through the same dialog so a mis-tap can't wipe the device.
+    func requestPanicWipe() {
+        showPanicConfirmation = true
+    }
+
     func panicClearAllData() {
+        // A wipe invalidates everything on screen, and its outcome must be
+        // visible: the success message and the failed-wipe banner both live
+        // on the root timeline, so a sheet left up (the App Info danger-zone
+        // path keeps its sheet presented) would hide the one signal that says
+        // whether the wipe worked.
+        isAppInfoPresented = false
+        isLocationChannelsSheetPresented = false
+        isNoticesSheetPresented = false
+        showingFingerprintFor = nil
+
+        prepareForPanic?()
+        onPanicWipe()
         chatViewModel.panicClearAllData()
     }
 
@@ -95,6 +171,14 @@ final class AppChromeModel: ObservableObject {
             .receive(on: DispatchQueue.main)
             .assign(to: &$bluetoothState)
 
+        chatViewModel.$torBlocked
+            .receive(on: DispatchQueue.main)
+            .assign(to: &$torBlocked)
+
+        chatViewModel.$panicRecoveryBlocked
+            .receive(on: DispatchQueue.main)
+            .assign(to: &$panicWipeBlocked)
+
         hasUnreadPrivateMessages = !privateInboxModel.unreadPeerIDs.isEmpty
     }
 }

bitchat/App/AppRuntime.swift

@@ -18,8 +18,6 @@ final class AppRuntime: ObservableObject {
     /// (docs/CONVERSATION-STORE-DESIGN.md). Owned here; the feature models
     /// and `ChatViewModel` observe and mutate it through its intent API.
     let conversations: ConversationStore
-    let peerIdentityStore: PeerIdentityStore
-    let locationPresenceStore: LocationPresenceStore
     let publicChatModel: PublicChatModel
     let privateInboxModel: PrivateInboxModel
     let privateConversationModel: PrivateConversationModel
@@ -28,6 +26,8 @@ final class AppRuntime: ObservableObject {
     let locationChannelsModel: LocationChannelsModel
     let peerListModel: PeerListModel
     let appChromeModel: AppChromeModel
+    let boardAlertsModel: BoardAlertsModel
+    let sharedContentImportModel: SharedContentImportModel
 
     private let idBridge: NostrIdentityBridge
     private var cancellables = Set<AnyCancellable>()
@@ -41,8 +41,9 @@ final class AppRuntime: ObservableObject {
     #endif
 
     init(
-        keychain: KeychainManagerProtocol = KeychainManager(),
-        idBridge: NostrIdentityBridge = NostrIdentityBridge()
+        keychain: KeychainManagerProtocol = KeychainManager.makeDefault(),
+        idBridge: NostrIdentityBridge = NostrIdentityBridge(),
+        sharedContentStore: SharedContentStore? = nil
     ) {
         self.idBridge = idBridge
         let conversations = ConversationStore()
@@ -50,8 +51,6 @@ final class AppRuntime: ObservableObject {
         let locationPresenceStore = LocationPresenceStore()
         let locationManager = LocationChannelManager.shared
         self.conversations = conversations
-        self.peerIdentityStore = peerIdentityStore
-        self.locationPresenceStore = locationPresenceStore
         self.chatViewModel = ChatViewModel(
             keychain: keychain,
             idBridge: idBridge,
@@ -87,17 +86,48 @@ final class AppRuntime: ObservableObject {
             peerIdentityStore: peerIdentityStore,
             locationPresenceStore: locationPresenceStore
         )
+        let resolvedSharedContentStore: SharedContentStore?
+        if let sharedContentStore {
+            resolvedSharedContentStore = sharedContentStore
+        } else if let sharedDefaults = UserDefaults(suiteName: BitchatApp.groupID) {
+            resolvedSharedContentStore = SharedContentStore(defaults: sharedDefaults)
+        } else {
+            resolvedSharedContentStore = nil
+        }
+        let sharedContentImportModel = SharedContentImportModel(store: resolvedSharedContentStore)
+        self.sharedContentImportModel = sharedContentImportModel
         self.appChromeModel = AppChromeModel(
             chatViewModel: self.chatViewModel,
-            privateInboxModel: self.privateInboxModel
+            privateInboxModel: self.privateInboxModel,
+            onPanicWipe: { sharedContentImportModel.discardAll() }
         )
-
-        GeoRelayDirectory.shared.prefetchIfNeeded()
+        let chatViewModel = self.chatViewModel
+        self.boardAlertsModel = BoardAlertsModel(
+            arrivals: BoardStore.shared.postArrivals.eraseToAnyPublisher(),
+            wipes: BoardStore.shared.didWipe.eraseToAnyPublisher(),
+            dependencies: BoardAlertsModel.Dependencies(
+                isOwnPost: { post in
+                    let key = chatViewModel.meshService.noiseSigningPublicKeyData()
+                    return !key.isEmpty && key == post.authorSigningKey
+                },
+                emitSystemLine: { content, geohash in
+                    if geohash.isEmpty {
+                        chatViewModel.addMeshOnlySystemMessage(content)
+                    } else {
+                        chatViewModel.addGeohashSystemMessage(content, geohash: geohash)
+                    }
+                }
+            )
+        )
+        if chatViewModel.networkActivationAllowed {
+            GeoRelayDirectory.shared.prefetchIfNeeded()
+        }
         bindRuntimeObservers()
         NotificationDelegate.shared.runtime = self
     }
 
     func start() {
+        guard chatViewModel.networkActivationAllowed else { return }
         guard !started else {
             checkForSharedContent()
             return
@@ -122,11 +152,26 @@ final class AppRuntime: ObservableObject {
         NetworkActivationService.shared.start()
         GeohashPresenceService.shared.start()
         checkForSharedContent()
+        performMediaMaintenance()
 
         record(.launched)
         record(.startupCompleted)
     }
 
+    /// Drops media that has outlived the retention window, then applies the
+    /// explicit protection class to files that older builds wrote without
+    /// one. Expiry runs first so the migration never touches files the
+    /// sweep is about to delete. Detached because `AppRuntime` is
+    /// main-actor and both passes go file by file through the media tree;
+    /// best-effort, nothing at launch depends on their results.
+    private func performMediaMaintenance() {
+        Task.detached(priority: .utility) {
+            let store = BLEIncomingFileStore()
+            store.expireAgedMedia()
+            store.migrateFileProtectionIfNeeded()
+        }
+    }
+
     func handleOpenURL(_ url: URL) {
         record(.openedURL(url.absoluteString))
 
@@ -136,12 +181,14 @@ final class AppRuntime: ObservableObject {
     }
 
     func handleDidBecomeActiveNotification() {
+        guard chatViewModel.networkActivationAllowed else { return }
         chatViewModel.handleDidBecomeActive()
         checkForSharedContent()
     }
 
     #if os(macOS)
     func handleMacDidBecomeActiveNotification() {
+        guard chatViewModel.networkActivationAllowed else { return }
         record(.scenePhaseChanged(.active))
         chatViewModel.handleDidBecomeActive()
         checkForSharedContent()
@@ -160,6 +207,7 @@ final class AppRuntime: ObservableObject {
             didEnterBackground = true
 
         case .active:
+            guard chatViewModel.networkActivationAllowed else { return }
             record(.scenePhaseChanged(.active))
             chatViewModel.meshService.startServices()
             TorManager.shared.setAppForeground(true)
@@ -202,7 +250,17 @@ final class AppRuntime: ObservableObject {
         chatViewModel.applicationWillTerminate()
     }
 
-    func handleNotificationResponse(identifier: String, userInfo: [AnyHashable: Any]) {
+    func handleNotificationResponse(
+        identifier: String,
+        actionIdentifier: String = UNNotificationDefaultActionIdentifier,
+        userInfo: [AnyHashable: Any]
+    ) {
+        guard chatViewModel.networkActivationAllowed else { return }
+        if actionIdentifier == NotificationService.waveActionID {
+            chatViewModel.sendMeshWave()
+            return
+        }
+
         if identifier.hasPrefix("private-"), let peerID = PeerID(str: userInfo["peerID"] as? String) {
             record(.notificationOpened(peerID: peerID))
             chatViewModel.startPrivateChat(with: peerID)
@@ -249,6 +307,8 @@ private extension AppRuntime {
         NotificationCenter.default.publisher(for: .TorWillRestart)
             .receive(on: DispatchQueue.main)
             .sink { [weak self] _ in
+                guard self?.chatViewModel.networkActivationAllowed == true
+                else { return }
                 self?.record(.torLifecycleChanged(.willRestart))
                 self?.chatViewModel.handleTorWillRestart()
             }
@@ -257,6 +317,8 @@ private extension AppRuntime {
         NotificationCenter.default.publisher(for: .TorDidBecomeReady)
             .receive(on: DispatchQueue.main)
             .sink { [weak self] _ in
+                guard self?.chatViewModel.networkActivationAllowed == true
+                else { return }
                 self?.record(.torLifecycleChanged(.didBecomeReady))
                 self?.chatViewModel.handleTorDidBecomeReady()
             }
@@ -265,14 +327,28 @@ private extension AppRuntime {
         NotificationCenter.default.publisher(for: .TorWillStart)
             .receive(on: DispatchQueue.main)
             .sink { [weak self] _ in
+                guard self?.chatViewModel.networkActivationAllowed == true
+                else { return }
                 self?.record(.torLifecycleChanged(.willStart))
                 self?.chatViewModel.handleTorWillStart()
             }
             .store(in: &cancellables)
 
+        NotificationCenter.default.publisher(for: .TorBootstrapDidStall)
+            .receive(on: DispatchQueue.main)
+            .sink { [weak self] _ in
+                guard self?.chatViewModel.networkActivationAllowed == true
+                else { return }
+                self?.record(.torLifecycleChanged(.bootstrapDidStall))
+                self?.chatViewModel.handleTorBootstrapDidStall()
+            }
+            .store(in: &cancellables)
+
         NotificationCenter.default.publisher(for: .TorUserPreferenceChanged)
             .receive(on: DispatchQueue.main)
             .sink { [weak self] notification in
+                guard self?.chatViewModel.networkActivationAllowed == true
+                else { return }
                 self?.record(.torLifecycleChanged(.preferenceChanged))
                 self?.chatViewModel.handleTorPreferenceChanged(notification)
             }
@@ -289,36 +365,22 @@ private extension AppRuntime {
     }
 
     func checkForSharedContent() {
-        guard let userDefaults = UserDefaults(suiteName: BitchatApp.groupID),
-              let sharedContent = userDefaults.string(forKey: "sharedContent"),
-              let sharedDate = userDefaults.object(forKey: "sharedContentDate") as? Date else {
-            return
+        let previousID = sharedContentImportModel.offer?.id
+        guard let payload = sharedContentImportModel.refresh(
+            destination: currentSharedContentDestination
+        ) else { return }
+
+        if previousID != payload.id {
+            record(.sharedContentReadyForReview(payload.kind))
         }
+    }
 
-        guard Date().timeIntervalSince(sharedDate) < TransportConfig.uiShareAcceptWindowSeconds else {
-            return
-        }
-
-        let contentKind = SharedContentKind(rawValue: userDefaults.string(forKey: "sharedContentType") ?? "") ?? .text
-
-        userDefaults.removeObject(forKey: "sharedContent")
-        userDefaults.removeObject(forKey: "sharedContentType")
-        userDefaults.removeObject(forKey: "sharedContentDate")
-
-        switch contentKind {
-        case .url:
-            if let data = sharedContent.data(using: .utf8),
-               let urlData = try? JSONSerialization.jsonObject(with: data) as? [String: String],
-               let url = urlData["url"] {
-                chatViewModel.sendMessage(url)
-            } else {
-                chatViewModel.sendMessage(sharedContent)
-            }
-        case .text:
-            chatViewModel.sendMessage(sharedContent)
-        }
-
-        record(.sharedContentAccepted(contentKind))
+    var currentSharedContentDestination: SharedContentDestination {
+        SharedContentDestination.resolve(
+            selectedPrivatePeerID: privateConversationModel.selectedPeerID,
+            privateDisplayName: privateConversationModel.selectedHeaderState?.displayName,
+            activeChannel: locationChannelsModel.selectedChannel
+        )
     }
 
     func handleNostrRelayConnectionChanged(_ isConnected: Bool) {
@@ -327,7 +389,9 @@ private extension AppRuntime {
         let becameConnected = isConnected && !lastNostrRelayConnectedState
         lastNostrRelayConnectedState = isConnected
 
-        guard started, becameConnected else { return }
+        guard chatViewModel.networkActivationAllowed,
+              started,
+              becameConnected else { return }
 
         let isInitialConnection = !didHandleInitialNostrConnection
         didHandleInitialNostrConnection = true
@@ -360,16 +424,24 @@ private extension AppRuntime {
     }
 
     func handleScreenshotCaptured() {
-        if appChromeModel.isLocationChannelsSheetPresented {
+        let isLocationChannelActive: Bool = {
+            if case .location = chatViewModel.activeChannel { return true }
+            return false
+        }()
+
+        switch Self.resolveScreenshotResponse(
+            isLocationChannelsSheetPresented: appChromeModel.isLocationChannelsSheetPresented,
+            isAppInfoPresented: appChromeModel.isAppInfoPresented,
+            hasPrivateChatOpen: chatViewModel.selectedPrivateChatPeer != nil,
+            isLocationChannelActive: isLocationChannelActive
+        ) {
+        case .warnLocally:
             appChromeModel.triggerScreenshotPrivacyWarning()
-            return
+        case .ignore:
+            break
+        case .forwardToChat:
+            chatViewModel.handleScreenshotCaptured()
         }
-
-        if appChromeModel.isAppInfoPresented {
-            return
-        }
-
-        chatViewModel.handleScreenshotCaptured()
     }
 
     func openExternalURL(_ url: URL) {
@@ -386,3 +458,40 @@ private extension AppRuntime {
         }
     }
 }
+
+// MARK: - Screenshot routing
+
+extension AppRuntime {
+    /// What a screenshot triggers. Nothing on this table sends anything to
+    /// a public channel (see `ChatLifecycleCoordinator.handleScreenshotCaptured`).
+    enum ScreenshotCaptureResponse: Equatable {
+        /// Show the local location-privacy alert; nothing is sent anywhere.
+        case warnLocally
+        /// Do nothing. App Info holds no conversation or location content.
+        case ignore
+        /// Hand to the chat layer: a DM notice goes to the peer when a
+        /// secure session exists; public timelines stay silent. Mesh
+        /// deliberately gets no local alert either — a mesh screenshot
+        /// reveals no place and triggers no send, so there is nothing to
+        /// warn about, and alerting on every screenshot would train people
+        /// to dismiss the one alert that matters (the location one).
+        case forwardToChat
+    }
+
+    /// Pure decision table so the screenshot routing is testable without a
+    /// runtime.
+    nonisolated static func resolveScreenshotResponse(
+        isLocationChannelsSheetPresented: Bool,
+        isAppInfoPresented: Bool,
+        hasPrivateChatOpen: Bool,
+        isLocationChannelActive: Bool
+    ) -> ScreenshotCaptureResponse {
+        if isLocationChannelsSheetPresented { return .warnLocally }
+        if isAppInfoPresented { return .ignore }
+        // A geohash timeline screenshot still reveals a place — warn the
+        // person taking it, locally, with the same alert the channel sheet
+        // uses.
+        if !hasPrivateChatOpen, isLocationChannelActive { return .warnLocally }
+        return .forwardToChat
+    }
+}

bitchat/App/ConversationStore.swift

@@ -39,15 +39,17 @@ final class Conversation: ObservableObject, Identifiable {
     @Published private(set) var messages: [BitchatMessage] = []
     @Published private(set) var isUnread: Bool = false
 
-    /// Incrementally-maintained message-ID → index map for O(1) dedup and
-    /// delivery-status lookup. Kept in sync on every mutation:
-    /// - tail append: single insert
-    /// - out-of-order insert: suffix reindex from the insertion point
-    /// - trim: full rebuild — `removeFirst(k)` is already O(n), so the
-    ///   rebuild does not change the asymptotics, and trim only happens once
-    ///   the cap (1337) is reached. Simple and correct beats the
-    ///   offset-tracking alternative here.
+    /// Incrementally-maintained message-ID → logical-index map for O(1)
+    /// dedup and delivery-status lookup. Logical indexes are physical array
+    /// indexes plus `indexOffset`; trimming from the head advances the offset
+    /// instead of rewriting every surviving dictionary entry. This matters
+    /// after the 1337-message cap is reached, when every steady-state tail
+    /// append evicts one old row.
+    ///
+    /// Out-of-order inserts and middle removals still reindex only the
+    /// affected suffix. Full filtering resets the offset while rebuilding.
     private var indexByMessageID: [String: Int] = [:]
+    private var indexOffset = 0
 
     fileprivate init(id: ConversationID, cap: Int) {
         self.id = id
@@ -61,7 +63,7 @@ final class Conversation: ObservableObject, Identifiable {
     }
 
     func message(withID messageID: String) -> BitchatMessage? {
-        guard let index = indexByMessageID[messageID] else { return nil }
+        guard let index = physicalIndex(forMessageID: messageID) else { return nil }
         return messages[index]
     }
 
@@ -101,7 +103,7 @@ final class Conversation: ObservableObject, Identifiable {
             reindex(from: index)
         } else {
             messages.append(message)
-            indexByMessageID[message.id] = messages.count - 1
+            indexByMessageID[message.id] = indexOffset + messages.count - 1
         }
 
         return InsertResult(inserted: true, trimmedMessageIDs: trimIfNeeded())
@@ -111,7 +113,7 @@ final class Conversation: ObservableObject, Identifiable {
     /// timeline position (in-place updates like media progress reuse the
     /// original timestamp); a new message goes through ordered insertion.
     fileprivate func upsert(_ message: BitchatMessage) -> UpsertOutcome {
-        if let index = indexByMessageID[message.id] {
+        if let index = physicalIndex(forMessageID: message.id) {
             messages[index] = message
             return .updated
         }
@@ -125,7 +127,7 @@ final class Conversation: ObservableObject, Identifiable {
     /// `.read` is never downgraded to `.delivered` or `.sent`.
     /// Returns `true` when the status was applied.
     fileprivate func applyDeliveryStatus(_ status: DeliveryStatus, forMessageID messageID: String) -> Bool {
-        guard let index = indexByMessageID[messageID] else { return false }
+        guard let index = physicalIndex(forMessageID: messageID) else { return false }
         let message = messages[index]
         guard !Self.shouldSkipStatusUpdate(current: message.deliveryStatus, new: status) else { return false }
 
@@ -142,7 +144,7 @@ final class Conversation: ObservableObject, Identifiable {
     /// observers still need an @Published emission to re-render.
     @discardableResult
     fileprivate func republishMessage(withID messageID: String) -> Bool {
-        guard let index = indexByMessageID[messageID] else { return false }
+        guard let index = physicalIndex(forMessageID: messageID) else { return false }
         messages[index] = messages[index]
         return true
     }
@@ -157,10 +159,14 @@ final class Conversation: ObservableObject, Identifiable {
     /// Removes a single message by ID. Returns the removed message, or
     /// `nil` when no message with that ID exists.
     fileprivate func remove(messageID: String) -> BitchatMessage? {
-        guard let index = indexByMessageID[messageID] else { return nil }
+        guard let index = physicalIndex(forMessageID: messageID) else { return nil }
         let removed = messages.remove(at: index)
         indexByMessageID.removeValue(forKey: messageID)
-        reindex(from: index)
+        if index == 0 {
+            indexOffset += 1
+        } else {
+            reindex(from: index)
+        }
         return removed
     }
 
@@ -177,6 +183,7 @@ final class Conversation: ObservableObject, Identifiable {
         for id in removedIDs {
             indexByMessageID.removeValue(forKey: id)
         }
+        indexOffset = 0
         reindex(from: 0)
         return removedIDs
     }
@@ -184,6 +191,7 @@ final class Conversation: ObservableObject, Identifiable {
     fileprivate func clearMessages() {
         messages.removeAll()
         indexByMessageID.removeAll()
+        indexOffset = 0
     }
 
     // MARK: Diagnostics
@@ -205,9 +213,10 @@ final class Conversation: ObservableObject, Identifiable {
             let message = messages[position]
             // Count equality + every message resolving to its own position
             // proves the index is exactly the inverse map (no stale extras).
-            if let index = indexByMessageID[message.id] {
-                if index != position {
-                    violations.append("\(label): message \(message.id.prefix(8))… at \(position) indexed at \(index)")
+            if let logicalIndex = indexByMessageID[message.id] {
+                let expectedIndex = indexOffset + position
+                if logicalIndex != expectedIndex {
+                    violations.append("\(label): message \(message.id.prefix(8))… at \(position) indexed at \(logicalIndex - indexOffset)")
                 }
             } else {
                 violations.append("\(label): message \(message.id.prefix(8))… at \(position) missing from index")
@@ -221,12 +230,32 @@ final class Conversation: ObservableObject, Identifiable {
 
     // MARK: Internals
 
-    static func shouldSkipStatusUpdate(current: DeliveryStatus?, new: DeliveryStatus) -> Bool {
-        guard let current else { return false }
+    static func shouldSkipStatusUpdate(current: DeliveryStatus, new: DeliveryStatus) -> Bool {
         if current == new { return true }
 
+        // Never downgrade to a weaker delivery state. Ordering of certainty:
+        // sending < sent < carried < delivered < read. A late `.sent` write
+        // (e.g. the optimistic stamp after routing) must not clobber the
+        // `.carried` the router already set when it handed a copy to a
+        // courier/bridge, nor a `.delivered`/`.read` ack. A late asynchronous
+        // failure is weaker than a confirmed recipient receipt too, so it may
+        // not replace `.delivered`/`.read`. Same for the
+        // `.sending` stamp a pre-handshake resend emits asynchronously: it
+        // can land after the message already reached `.sent`, and "Sent" was
+        // already truthful. (`.failed` → `.sending` stays allowed so a real
+        // failure retry is visible.)
         switch (current, new) {
-        case (.read, .delivered), (.read, .sent):
+        case (.read, .delivered), (.read, .carried), (.read, .sent), (.read, .sending), (.read, .failed):
+            return true
+        case (.delivered, .carried), (.delivered, .sent), (.delivered, .sending), (.delivered, .failed):
+            return true
+        case (.carried, .sent), (.carried, .sending):
+            return true
+        case (.sent, .sending):
+            return true
+        case (_, .notSentYet):
+            // .notSentYet is the pre-transport initial state; once a message
+            // has any real status, resetting to it is always a downgrade.
             return true
         default:
             return false
@@ -252,10 +281,17 @@ final class Conversation: ObservableObject, Identifiable {
 
     private func reindex(from start: Int) {
         for index in start..<messages.count {
-            indexByMessageID[messages[index].id] = index
+            indexByMessageID[messages[index].id] = indexOffset + index
         }
     }
 
+    private func physicalIndex(forMessageID messageID: String) -> Int? {
+        guard let logicalIndex = indexByMessageID[messageID] else { return nil }
+        let index = logicalIndex - indexOffset
+        guard messages.indices.contains(index) else { return nil }
+        return index
+    }
+
     /// Trims oldest messages over the cap; returns the trimmed message IDs.
     private func trimIfNeeded() -> [String] {
         guard messages.count > cap else { return [] }
@@ -265,7 +301,7 @@ final class Conversation: ObservableObject, Identifiable {
             indexByMessageID.removeValue(forKey: id)
         }
         messages.removeFirst(overflow)
-        reindex(from: 0)
+        indexOffset += overflow
         return trimmedIDs
     }
 }
@@ -409,6 +445,40 @@ final class ConversationStore: ObservableObject {
     @discardableResult
     func setDeliveryStatus(_ status: DeliveryStatus, forMessageID messageID: String) -> Bool {
         guard let ids = conversationIDsByMessageID[messageID] else { return false }
+        return applyDeliveryStatus(status, forMessageID: messageID, among: ids)
+    }
+
+    /// Applies an authenticated delivery/read receipt only to the supplied
+    /// direct-conversation aliases. A colliding message ID in another peer's
+    /// conversation (or a public timeline) must not inherit the receipt.
+    ///
+    /// Stable and ephemeral aliases can temporarily hold the same message
+    /// instance during handoff. The shared helper republishes every targeted
+    /// alias even when the first mutation already changed that instance.
+    @discardableResult
+    func setDeliveryStatus(
+        _ status: DeliveryStatus,
+        forMessageID messageID: String,
+        inDirectPeerAliases peerIDs: Set<PeerID>
+    ) -> Bool {
+        guard !peerIDs.isEmpty,
+              let indexedIDs = conversationIDsByMessageID[messageID] else {
+            return false
+        }
+        let allowedIDs = Set(peerIDs.map { ConversationID.directPeer($0) })
+        return applyDeliveryStatus(
+            status,
+            forMessageID: messageID,
+            among: indexedIDs.intersection(allowedIDs)
+        )
+    }
+
+    private func applyDeliveryStatus(
+        _ status: DeliveryStatus,
+        forMessageID messageID: String,
+        among ids: Set<ConversationID>
+    ) -> Bool {
+        guard !ids.isEmpty else { return false }
         var applied = false
         var skipped: [ConversationID] = []
         for id in ids {
@@ -796,16 +866,6 @@ extension ConversationStore {
         return messageIDs
     }
 
-    /// Removes every direct conversation (panic clear).
-    func removeAllDirectConversations() {
-        let directIDs = conversationIDs.filter { id in
-            if case .direct = id { return true }
-            return false
-        }
-        for id in directIDs {
-            removeConversation(id)
-        }
-    }
 }
 
 // MARK: - Diagnostics support
@@ -837,8 +897,8 @@ extension Conversation {
     /// (positions 0 and 1 swap their index entries). Requires >= 2 messages.
     func _testCorruptIndexEntries() {
         guard messages.count >= 2 else { return }
-        indexByMessageID[messages[0].id] = 1
-        indexByMessageID[messages[1].id] = 0
+        indexByMessageID[messages[0].id] = indexOffset + 1
+        indexByMessageID[messages[1].id] = indexOffset
     }
 
     /// Drops a message's index entry entirely (count mismatch + missing).
@@ -852,8 +912,8 @@ extension Conversation {
     func _testCorruptOrderingPreservingIndex() {
         guard messages.count >= 2 else { return }
         messages.swapAt(0, messages.count - 1)
-        indexByMessageID[messages[0].id] = 0
-        indexByMessageID[messages[messages.count - 1].id] = messages.count - 1
+        indexByMessageID[messages[0].id] = indexOffset
+        indexByMessageID[messages[messages.count - 1].id] = indexOffset + messages.count - 1
     }
 }
 
@@ -893,7 +953,7 @@ extension ConversationStore {
 extension Conversation {
     fileprivate func _testAppendBypassingTrim(_ message: BitchatMessage) {
         messages.append(message)
-        indexByMessageID[message.id] = messages.count - 1
+        indexByMessageID[message.id] = indexOffset + messages.count - 1
     }
 }
 #endif

bitchat/App/ConversationUIModel.swift

@@ -9,9 +9,14 @@ import UIKit
 final class ConversationUIModel: ObservableObject {
     @Published private(set) var showAutocomplete = false
     @Published private(set) var autocompleteSuggestions: [String] = []
+    @Published private(set) var selectedAutocompleteIndex = 0
     @Published private(set) var currentNickname: String
     @Published private(set) var isBatchingPublic = false
     @Published private(set) var canSendMediaInCurrentContext = true
+    @Published private(set) var legacyPrivateMediaConsentRequest: LegacyPrivateMediaConsentRequest?
+    /// Who is talking live in the public mesh channel right now (floor
+    /// courtesy: the composer mic tints "busy" while someone holds the floor).
+    @Published private(set) var activeLiveVoiceTalker: String?
 
     private let chatViewModel: ChatViewModel
     private let privateConversationModel: PrivateConversationModel
@@ -32,6 +37,7 @@ final class ConversationUIModel: ObservableObject {
         self.isBatchingPublic = chatViewModel.isBatchingPublic
         self.showAutocomplete = chatViewModel.showAutocomplete
         self.autocompleteSuggestions = chatViewModel.autocompleteSuggestions
+        self.selectedAutocompleteIndex = chatViewModel.selectedAutocompleteIndex
         self.canSendMediaInCurrentContext = chatViewModel.canSendMediaInCurrentContext
 
         bind()
@@ -49,6 +55,14 @@ final class ConversationUIModel: ObservableObject {
         chatViewModel.sendMessage(message)
     }
 
+    /// Resends a failed private message through the normal send path,
+    /// removing the failed original so the re-submission replaces it
+    /// instead of stacking a duplicate under the red bubble.
+    func resendFailedPrivateMessage(_ message: BitchatMessage) {
+        chatViewModel.removePrivateMessage(withID: message.id)
+        chatViewModel.sendMessage(message.content)
+    }
+
     func clearCurrentConversation() {
         chatViewModel.sendMessage("/clear")
     }
@@ -67,11 +81,23 @@ final class ConversationUIModel: ObservableObject {
         if let peerID, peerID.isGeoChat,
            let full = chatViewModel.fullNostrHex(forSenderPeerID: peerID) {
             chatViewModel.blockGeohashUser(pubkeyHexLowercased: full, displayName: displayName)
+        } else if let peerID, !peerID.isGeoDM, !peerID.isGeoChat {
+            // Mesh: block the peer's stable Noise identity resolved from the
+            // tapped peerID rather than re-resolving a display-name string.
+            chatViewModel.blockMeshPeer(peerID: peerID, displayName: displayName)
         } else {
             chatViewModel.sendMessage("/block \(displayName)")
         }
     }
 
+    /// Mesh counterpart of `block(peerID:displayName:)`. Resolves the unblock by
+    /// the tapped peer's stable identity so the exact row is unblocked — this
+    /// also works for offline peers, which the `/unblock <displayName>` command
+    /// cannot resolve.
+    func unblock(peerID: PeerID, displayName: String) {
+        chatViewModel.unblockMeshPeer(peerID: peerID, displayName: displayName)
+    }
+
     func updateAutocomplete(for text: String, cursorPosition: Int) {
         chatViewModel.updateAutocomplete(for: text, cursorPosition: cursorPosition)
     }
@@ -80,6 +106,31 @@ final class ConversationUIModel: ObservableObject {
         chatViewModel.completeNickname(nickname, in: &text)
     }
 
+    /// Accept the currently highlighted mention suggestion, if any.
+    func completeSelectedSuggestion(in text: inout String) -> Bool {
+        guard showAutocomplete,
+              autocompleteSuggestions.indices.contains(selectedAutocompleteIndex)
+        else { return false }
+        _ = completeNickname(autocompleteSuggestions[selectedAutocompleteIndex], in: &text)
+        return true
+    }
+
+    /// Dismiss the mention suggestion panel without inserting (Escape).
+    func dismissAutocomplete() {
+        guard showAutocomplete else { return }
+        chatViewModel.showAutocomplete = false
+        chatViewModel.autocompleteSuggestions = []
+        chatViewModel.autocompleteRange = nil
+        chatViewModel.selectedAutocompleteIndex = 0
+    }
+
+    func moveAutocompleteSelection(by delta: Int) {
+        guard showAutocomplete, !autocompleteSuggestions.isEmpty else { return }
+        let count = min(4, autocompleteSuggestions.count)
+        let next = (selectedAutocompleteIndex + delta + count) % count
+        chatViewModel.selectedAutocompleteIndex = next
+    }
+
     func formatMessage(_ message: BitchatMessage, colorScheme: ColorScheme, theme: AppTheme? = nil) -> AttributedString {
         chatViewModel.formatMessageAsText(message, colorScheme: colorScheme, theme: theme)
     }
@@ -104,6 +155,18 @@ final class ConversationUIModel: ObservableObject {
         message.sender == currentNickname || message.senderPeerID == chatViewModel.meshService.myPeerID
     }
 
+    /// Whether a private-message row should show the filled verification seal
+    /// next to the sender name (#1439). Scoped to DMs only — public timelines
+    /// have different trust semantics and stay undressed.
+    func showsVerifiedSeal(for message: BitchatMessage) -> Bool {
+        guard message.isPrivate,
+              message.sender != "system",
+              !isSentByCurrentUser(message),
+              let peerID = message.senderPeerID else { return false }
+        guard let fingerprint = chatViewModel.getFingerprint(for: peerID) else { return false }
+        return chatViewModel.peerIdentityStore.isVerified(fingerprint)
+    }
+
     func senderDisplayName(for peerID: PeerID, fallbackMessages: [BitchatMessage]) -> String? {
         if peerID.isGeoDM || peerID.isGeoChat {
             return chatViewModel.geohashDisplayName(for: peerID)
@@ -130,6 +193,24 @@ final class ConversationUIModel: ObservableObject {
         chatViewModel.sendVoiceNote(at: url)
     }
 
+    func resolveLegacyPrivateMediaConsent(requestID: UUID, approved: Bool) {
+        chatViewModel.resolveLegacyPrivateMediaConsent(
+            requestID: requestID,
+            approved: approved
+        )
+    }
+
+    /// Capture backend for the mic gesture: live PTT when the current DM
+    /// peer can hear it now, classic voice note otherwise.
+    func makeVoiceCaptureSession() -> VoiceCaptureSession {
+        chatViewModel.makeVoiceCaptureSession()
+    }
+
+    /// Whether this message is a live voice burst still streaming in.
+    func isLiveVoiceMessage(_ message: BitchatMessage) -> Bool {
+        chatViewModel.liveVoiceCoordinator.isLiveVoiceMessage(message)
+    }
+
     func cancelMediaSend(messageID: String) {
         chatViewModel.cancelMediaSend(messageID: messageID)
     }
@@ -151,10 +232,22 @@ final class ConversationUIModel: ObservableObject {
             .receive(on: DispatchQueue.main)
             .assign(to: &$autocompleteSuggestions)
 
+        chatViewModel.$selectedAutocompleteIndex
+            .receive(on: DispatchQueue.main)
+            .assign(to: &$selectedAutocompleteIndex)
+
         chatViewModel.$isBatchingPublic
             .receive(on: DispatchQueue.main)
             .assign(to: &$isBatchingPublic)
 
+        chatViewModel.$activePublicVoiceTalker
+            .receive(on: DispatchQueue.main)
+            .assign(to: &$activeLiveVoiceTalker)
+
+        chatViewModel.$legacyPrivateMediaConsentRequest
+            .receive(on: DispatchQueue.main)
+            .assign(to: &$legacyPrivateMediaConsentRequest)
+
         conversations.$activeChannel
             .receive(on: DispatchQueue.main)
             .sink { [weak self] channel in
@@ -169,11 +262,22 @@ final class ConversationUIModel: ObservableObject {
                 self?.refreshComputedState()
             }
             .store(in: &cancellables)
+
+        // Verify/unverify while a DM is open must repaint existing rows —
+        // showsVerifiedSeal is computed per render, so forward the store change.
+        chatViewModel.peerIdentityStore.$verifiedFingerprints
+            .receive(on: DispatchQueue.main)
+            .sink { [weak self] _ in
+                self?.objectWillChange.send()
+            }
+            .store(in: &cancellables)
     }
 
     private func refreshComputedState() {
         if let selectedPeerID = privateConversationModel.selectedPeerID {
-            canSendMediaInCurrentContext = !(selectedPeerID.isGeoDM || selectedPeerID.isGeoChat)
+            // Media transfer is not wired for groups in v1; keep it off so the
+            // composer can't strand a media placeholder that never sends.
+            canSendMediaInCurrentContext = !(selectedPeerID.isGeoDM || selectedPeerID.isGeoChat || selectedPeerID.isGroup)
             return
         }
 

bitchat/App/LocationChannelsModel.swift

@@ -1,4 +1,3 @@
-import BitFoundation
 import Combine
 import Foundation
 
@@ -12,20 +11,25 @@ final class LocationChannelsModel: ObservableObject {
     @Published private(set) var bookmarkNames: [String: String]
     @Published private(set) var locationNames: [GeohashChannelLevel: String]
     @Published private(set) var userTorEnabled: Bool
+    @Published private(set) var gatewayEnabled: Bool
 
     private let manager: LocationChannelManager
     private let network: NetworkActivationService
-    private var cancellables = Set<AnyCancellable>()
+    private let gateway: GatewayService
 
     init(
         manager: LocationChannelManager? = nil,
-        network: NetworkActivationService? = nil
+        network: NetworkActivationService? = nil,
+        gateway: GatewayService? = nil
     ) {
         let manager = manager ?? .shared
         let network = network ?? .shared
+        let gateway = gateway ?? .shared
 
         self.manager = manager
         self.network = network
+        self.gateway = gateway
+        self.gatewayEnabled = gateway.isEnabled
         self.permissionState = manager.permissionState
         self.availableChannels = manager.availableChannels
         self.selectedChannel = manager.selectedChannel
@@ -160,6 +164,10 @@ final class LocationChannelsModel: ObservableObject {
         network.$userTorEnabled
             .receive(on: DispatchQueue.main)
             .assign(to: &$userTorEnabled)
+
+        gateway.$isEnabled
+            .receive(on: DispatchQueue.main)
+            .assign(to: &$gatewayEnabled)
     }
 
     private func level(forLength length: Int) -> GeohashChannelLevel {

bitchat/App/LocationPresenceStore.swift

@@ -7,45 +7,147 @@ final class LocationPresenceStore: ObservableObject {
     @Published private(set) var geoNicknames: [String: String] = [:]
     @Published private(set) var teleportedGeo: Set<String> = []
 
+    private let teleportedGeoCapacity: Int
+    private var teleportedGeoOrder: [String] = []
+    private let geoNicknameCapacity: Int
+    private var geoNicknameOrder: [String] = []
+
+    init(
+        teleportedGeoCapacity: Int = TransportConfig.geoTeleportedParticipantsCap,
+        geoNicknameCapacity: Int = TransportConfig.geoNicknameParticipantsCap
+    ) {
+        self.teleportedGeoCapacity = max(0, teleportedGeoCapacity)
+        self.geoNicknameCapacity = max(0, geoNicknameCapacity)
+    }
+
     func setCurrentGeohash(_ geohash: String?) {
-        currentGeohash = geohash?.lowercased()
+        let normalized = geohash?.lowercased()
+        if currentGeohash != normalized {
+            // Presence markers are scoped to the active geohash channel.
+            clearTeleportedGeo()
+            clearGeoNicknames()
+        }
+        currentGeohash = normalized
     }
 
     func setNickname(_ nickname: String, for pubkeyHex: String) {
-        geoNicknames[pubkeyHex.lowercased()] = nickname
+        guard geoNicknameCapacity > 0 else {
+            clearGeoNicknames()
+            return
+        }
+
+        let nickname = nickname.normalizedNickname
+        let key = pubkeyHex.lowercased()
+        if geoNicknames[key] != nil {
+            geoNicknames[key] = nickname
+            return
+        }
+
+        while geoNicknameOrder.count >= geoNicknameCapacity, let oldest = geoNicknameOrder.first {
+            geoNicknameOrder.removeFirst()
+            geoNicknames.removeValue(forKey: oldest)
+        }
+
+        geoNicknames[key] = nickname
+        geoNicknameOrder.append(key)
     }
 
     func replaceGeoNicknames(_ nicknames: [String: String]) {
-        geoNicknames = Dictionary(
-            uniqueKeysWithValues: nicknames.map { key, value in
-                (key.lowercased(), value)
-            }
-        )
+        guard geoNicknameCapacity > 0 else {
+            clearGeoNicknames()
+            return
+        }
+
+        var seen: Set<String> = []
+        var ordered: [String] = []
+        var normalized: [String: String] = [:]
+        for (key, value) in nicknames {
+            let lower = key.lowercased()
+            guard seen.insert(lower).inserted else { continue }
+            ordered.append(lower)
+            normalized[lower] = value.normalizedNickname
+        }
+        if ordered.count > geoNicknameCapacity {
+            let kept = Array(ordered.suffix(geoNicknameCapacity))
+            ordered = kept
+            normalized = Dictionary(uniqueKeysWithValues: kept.compactMap { key in
+                normalized[key].map { (key, $0) }
+            })
+        }
+        geoNicknameOrder = ordered
+        geoNicknames = normalized
     }
 
     func clearGeoNicknames() {
         geoNicknames.removeAll()
+        geoNicknameOrder.removeAll()
+    }
+
+    func retainGeoNicknames(keeping pubkeys: Set<String>) {
+        let allowed = Set(pubkeys.map { $0.lowercased() })
+        geoNicknameOrder = geoNicknameOrder.filter { allowed.contains($0) }
+        geoNicknames = geoNicknames.filter { allowed.contains($0.key) }
     }
 
     func markTeleported(_ pubkeyHex: String) {
-        teleportedGeo.insert(pubkeyHex.lowercased())
+        guard teleportedGeoCapacity > 0 else {
+            clearTeleportedGeo()
+            return
+        }
+
+        let key = pubkeyHex.lowercased()
+        guard !teleportedGeo.contains(key) else { return }
+
+        while teleportedGeoOrder.count >= teleportedGeoCapacity, let oldest = teleportedGeoOrder.first {
+            teleportedGeoOrder.removeFirst()
+            teleportedGeo.remove(oldest)
+        }
+
+        teleportedGeo.insert(key)
+        teleportedGeoOrder.append(key)
     }
 
     func clearTeleported(_ pubkeyHex: String) {
-        teleportedGeo.remove(pubkeyHex.lowercased())
+        let key = pubkeyHex.lowercased()
+        teleportedGeo.remove(key)
+        teleportedGeoOrder.removeAll { $0 == key }
     }
 
     func replaceTeleportedGeo(_ pubkeys: Set<String>) {
-        teleportedGeo = Set(pubkeys.map { $0.lowercased() })
+        guard teleportedGeoCapacity > 0 else {
+            clearTeleportedGeo()
+            return
+        }
+
+        var seen: Set<String> = []
+        var ordered: [String] = []
+        for key in pubkeys.map({ $0.lowercased() }) where !seen.contains(key) {
+            seen.insert(key)
+            ordered.append(key)
+        }
+        if ordered.count > teleportedGeoCapacity {
+            ordered = Array(ordered.suffix(teleportedGeoCapacity))
+        }
+        teleportedGeoOrder = ordered
+        teleportedGeo = Set(ordered)
+    }
+
+    func retainTeleportedGeo(keeping pubkeys: Set<String>) {
+        let allowed = Set(pubkeys.map { $0.lowercased() })
+        teleportedGeoOrder = teleportedGeoOrder.filter { allowed.contains($0) }
+        teleportedGeo = teleportedGeo.intersection(allowed)
     }
 
     func clearTeleportedGeo() {
         teleportedGeo.removeAll()
+        teleportedGeoOrder.removeAll()
     }
 
     func reset() {
         currentGeohash = nil
         geoNicknames.removeAll()
+        geoNicknameOrder.removeAll()
         teleportedGeo.removeAll()
+        teleportedGeoOrder.removeAll()
     }
 }

bitchat/App/NearbyNotesCounter.swift

@@ -0,0 +1,147 @@
+//
+// NearbyNotesCounter.swift
+// bitchat
+//
+// Counts unexpired location notes left at the user's current building-level
+// geohash so the empty mesh timeline can say "📍 3 notes left here". Only
+// subscribes while a view holds it active, and only when location notes are
+// enabled and location permission is already granted (it never prompts).
+// This is free and unencumbered software released into the public domain.
+//
+
+import Combine
+import Foundation
+
+@MainActor
+final class NearbyNotesCounter: ObservableObject {
+    static let shared = NearbyNotesCounter()
+
+    @Published private(set) var noteCount = 0
+    /// Whether an explicit notes act (the empty-timeline "check for notes"
+    /// tap, opening the notices sheet's geo tab, or a successful /drop) has
+    /// unlocked the counter this session. Until then nothing subscribes:
+    /// merely looking at the mesh timeline must not open a building-precision
+    /// relay REQ that leaks location passively.
+    @Published private(set) var revealed = false
+
+    private var manager: LocationNotesManager?
+    private var managerCancellable: AnyCancellable?
+    private var channelsCancellable: AnyCancellable?
+    private var permissionCancellable: AnyCancellable?
+    private var settingCancellable: AnyCancellable?
+    private var activeHolders = 0
+    private let locationManager: LocationChannelManager
+    private let managerFactory: @MainActor (String) -> LocationNotesManager
+    private let releaseManager: @MainActor (LocationNotesManager?) -> Void
+    private let locationNotesEnabled: @MainActor () -> Bool
+    private let locationNotesSettingsPublisher: AnyPublisher<Void, Never>
+
+    init(
+        locationManager: LocationChannelManager = .shared,
+        managerFactory: @escaping @MainActor (String) -> LocationNotesManager = { LocationNotesPool.shared.acquire($0) },
+        releaseManager: @escaping @MainActor (LocationNotesManager?) -> Void = { LocationNotesPool.shared.release($0) },
+        locationNotesEnabled: @escaping @MainActor () -> Bool = { LocationNotesSettings.enabled },
+        locationNotesSettings: AnyPublisher<Void, Never>? = nil
+    ) {
+        self.locationManager = locationManager
+        self.managerFactory = managerFactory
+        self.releaseManager = releaseManager
+        self.locationNotesEnabled = locationNotesEnabled
+        self.locationNotesSettingsPublisher = locationNotesSettings
+            ?? NotificationCenter.default
+                .publisher(for: LocationNotesSettings.didChangeNotification)
+                .map { _ in () }
+                .eraseToAnyPublisher()
+    }
+
+    /// Whether the empty-timeline "check for notes" hint should render.
+    /// The permission gate matters: `retarget()` never subscribes without
+    /// location authorization, so offering the hint to an unauthorized
+    /// install would be a silent dead-end — tap, `revealed` flips, the hint
+    /// vanishes, and nothing else happens for the session. The hint never
+    /// prompts; it simply stays hidden until permission exists. The caller
+    /// passes its own observed permission state so the hint re-renders when
+    /// authorization changes.
+    func offersRevealHint(permissionState: LocationChannelManager.PermissionState) -> Bool {
+        !revealed && locationNotesEnabled() && permissionState == .authorized
+    }
+
+    /// Marks the one explicit act that lets the counter subscribe. Sticky for
+    /// the rest of the session (the singleton's lifetime); `deactivate()`
+    /// deliberately does not reset it.
+    func reveal() {
+        guard !revealed else { return }
+        revealed = true
+        retarget()
+    }
+
+    /// Begins (or keeps) the notes subscription for the current building
+    /// geohash. Balanced by `deactivate()`; ref-counted so multiple views can
+    /// hold it.
+    func activate() {
+        activeHolders += 1
+        guard activeHolders == 1 else { return }
+        channelsCancellable = locationManager.$availableChannels
+            .receive(on: DispatchQueue.main)
+            .sink { [weak self] _ in self?.retarget() }
+        // CoreLocation can revoke authorization while the view remains
+        // mounted. `availableChannels` deliberately retains its last value,
+        // so permission must be an independent invalidation signal or the
+        // building REQ survives on stale coordinates.
+        permissionCancellable = locationManager.$permissionState
+            .receive(on: DispatchQueue.main)
+            .sink { [weak self] _ in self?.retarget() }
+        // The app-info kill switch must take effect immediately, not on the
+        // next location change or remount.
+        settingCancellable = locationNotesSettingsPublisher
+            .receive(on: DispatchQueue.main)
+            .sink { [weak self] _ in self?.retarget() }
+        retarget()
+    }
+
+    func deactivate() {
+        activeHolders = max(0, activeHolders - 1)
+        guard activeHolders == 0 else { return }
+        channelsCancellable = nil
+        permissionCancellable = nil
+        settingCancellable = nil
+        managerCancellable = nil
+        releaseManager(manager)
+        manager = nil
+        noteCount = 0
+    }
+
+    private func retarget() {
+        guard activeHolders > 0,
+              revealed,
+              locationNotesEnabled(),
+              locationManager.permissionState == .authorized,
+              let geohash = locationManager.availableChannels
+                  .first(where: { $0.level == .building })?.geohash
+        else {
+            managerCancellable = nil
+            releaseManager(manager)
+            manager = nil
+            noteCount = 0
+            return
+        }
+
+        if let manager {
+            guard manager.geohash != geohash.lowercased() else { return }
+            // Pooled managers are shared; never retarget one in place —
+            // release the old cell and acquire the new one.
+            managerCancellable = nil
+            releaseManager(manager)
+            self.manager = nil
+        }
+
+        let fresh = managerFactory(geohash)
+        manager = fresh
+        managerCancellable = fresh.$notes
+            .receive(on: DispatchQueue.main)
+            .sink { [weak self] notes in
+                let now = Date()
+                self?.noteCount = notes.filter { $0.expiresAt.map { $0 > now } ?? true }.count
+            }
+    }
+}

bitchat/App/PeerIdentityStore.swift

@@ -25,10 +25,6 @@ final class PeerIdentityStore: ObservableObject {
         stablePeerIDsByShortID[peerID] = stablePeerID
     }
 
-    func replaceStablePeerIDs(_ mappings: [PeerID: PeerID]) {
-        stablePeerIDsByShortID = mappings
-    }
-
     func fingerprint(for peerID: PeerID) -> String? {
         peerFingerprintsByPeerID[peerID]
     }
@@ -94,10 +90,6 @@ final class PeerIdentityStore: ObservableObject {
         invalidateEncryptionCache(for: peerID)
     }
 
-    func replaceEncryptionStatuses(_ statuses: [PeerID: EncryptionStatus]) {
-        encryptionStatuses = statuses
-    }
-
     func setVerifiedFingerprints(_ fingerprints: Set<String>) {
         verifiedFingerprints = fingerprints
     }

bitchat/App/PeerListModel.swift

@@ -14,6 +14,9 @@ struct MeshPeerRow: Identifiable, Equatable {
     let isMutualFavorite: Bool
     let encryptionStatus: EncryptionStatus
     let showsVerifiedBadgeWhenOffline: Bool
+    /// Vouched-for by someone I verified, without an explicit verification of
+    /// mine — rendered as the unfilled seal (verified gets the filled one).
+    let showsVouchedBadge: Bool
 
     var id: String { peerID.id }
 }
@@ -26,11 +29,37 @@ struct GeohashPersonRow: Identifiable, Equatable {
     let isBlocked: Bool
 }
 
+struct GroupChatRow: Identifiable, Equatable {
+    let peerID: PeerID
+    let name: String
+    let memberCount: Int
+    let isCreator: Bool
+    let hasUnread: Bool
+
+    var id: String { peerID.id }
+}
+
+/// A direct conversation whose person is NOT in any roster above it. Without
+/// this section, a DM from a passerby became unreachable the moment they went
+/// offline: the roster filters to connected/reachable/mutual-favorite, the
+/// header envelope only exists while unread, and /msg can't resolve offline
+/// strangers — the thread was still in memory with no row anywhere in the UI.
+struct RecentChatRow: Identifiable, Equatable {
+    let peerID: PeerID
+    let displayName: String
+    let hasUnread: Bool
+    let lastActivity: Date
+
+    var id: String { peerID.id }
+}
+
 @MainActor
 final class PeerListModel: ObservableObject {
     @Published private(set) var allPeers: [BitchatPeer] = []
     @Published private(set) var meshRows: [MeshPeerRow] = []
     @Published private(set) var geohashPeople: [GeohashPersonRow] = []
+    @Published private(set) var groupRows: [GroupChatRow] = []
+    @Published private(set) var recentChatRows: [RecentChatRow] = []
     @Published private(set) var reachableMeshPeerCount = 0
     @Published private(set) var connectedMeshPeerCount = 0
     @Published private(set) var visibleGeohashPeerCount = 0
@@ -129,6 +158,24 @@ final class PeerListModel: ObservableObject {
             }
             .store(in: &cancellables)
 
+        // Direct-conversation changes reorder or create recent-chat rows.
+        // Filtered to `.direct` so public-timeline traffic (every mesh or
+        // geohash message emits a change) doesn't rebuild the sheet.
+        conversations.changes
+            .receive(on: DispatchQueue.main)
+            .sink { [weak self] change in
+                guard case .direct = Self.changedConversationID(change) else { return }
+                self?.refresh()
+            }
+            .store(in: &cancellables)
+
+        chatViewModel.groupStore.$groups
+            .receive(on: DispatchQueue.main)
+            .sink { [weak self] _ in
+                self?.refresh()
+            }
+            .store(in: &cancellables)
+
         peerIdentityStore.$encryptionStatuses
             .receive(on: DispatchQueue.main)
             .sink { [weak self] _ in
@@ -183,17 +230,16 @@ final class PeerListModel: ObservableObject {
         let myPeerID = chatViewModel.meshService.myPeerID
         let meshRows = allPeers.map { peer in
             let isMe = peer.peerID == myPeerID
-            let verifiedBadge: Bool
-            if !isMe && !peer.isConnected,
-               let fingerprint = chatViewModel.getFingerprint(for: peer.peerID) {
-                verifiedBadge = peerIdentityStore.isVerified(fingerprint)
-            } else {
-                verifiedBadge = false
-            }
+            let fingerprint = isMe ? nil : chatViewModel.getFingerprint(for: peer.peerID)
+            let isVerifiedFingerprint = fingerprint.map { peerIdentityStore.isVerified($0) } ?? false
+            let verifiedBadge = !peer.isConnected && isVerifiedFingerprint
+            // Vouched is subordinate to verified: never show both seals.
+            let vouchedBadge = !isVerifiedFingerprint
+                && (fingerprint.map { chatViewModel.isVouchedFingerprint($0) } ?? false)
 
             return MeshPeerRow(
                 peerID: peer.peerID,
-                displayName: isMe ? chatViewModel.nickname : peer.nickname,
+                displayName: isMe ? chatViewModel.nickname : peer.displayName,
                 isMe: isMe,
                 hasUnread: chatViewModel.hasUnreadMessages(for: peer.peerID),
                 isBlocked: !isMe && chatViewModel.isPeerBlocked(peer.peerID),
@@ -202,7 +248,8 @@ final class PeerListModel: ObservableObject {
                 isReachable: peer.isReachable,
                 isMutualFavorite: peer.isMutualFavorite,
                 encryptionStatus: chatViewModel.getEncryptionStatus(for: peer.peerID),
-                showsVerifiedBadgeWhenOffline: verifiedBadge
+                showsVerifiedBadgeWhenOffline: verifiedBadge,
+                showsVouchedBadge: vouchedBadge
             )
         }
 
@@ -217,22 +264,133 @@ final class PeerListModel: ObservableObject {
         }
 
         let geohashPeople = buildGeohashPeople()
+        let groupRows = buildGroupRows()
+        let recentChatRows = buildRecentChatRows(meshRows: meshRows, geohashPeople: geohashPeople)
 
         self.meshRows = meshRows
         reachableMeshPeerCount = meshCounts.reachable
         connectedMeshPeerCount = meshCounts.connected
         self.geohashPeople = geohashPeople
         visibleGeohashPeerCount = geohashPeople.count
+        self.groupRows = groupRows
+        self.recentChatRows = recentChatRows
         renderID = (
             meshRows.map {
-                "\($0.id)-\($0.isConnected)-\($0.isReachable)-\($0.hasUnread)-\($0.isFavorite)-\($0.isBlocked)"
+                "\($0.id)-\($0.displayName)-\($0.isConnected)-\($0.isReachable)-\($0.hasUnread)-\($0.isFavorite)-\($0.isBlocked)"
             } +
             geohashPeople.map {
                 "geo:\($0.id)-\($0.isTeleported)-\($0.isBlocked)-\($0.displayName)"
+            } +
+            groupRows.map {
+                "group:\($0.id)-\($0.name)-\($0.memberCount)-\($0.hasUnread)"
+            } +
+            recentChatRows.map {
+                "chat:\($0.id)-\($0.displayName)-\($0.hasUnread)"
             }
         ).joined(separator: "|")
     }
 
+    /// Direct conversations with people absent from the rosters above:
+    /// the offline passerby DM, the geoDM from a channel since left. Rows
+    /// mirrored under both an ephemeral and a stable peer ID collapse to
+    /// one row per identity (newest activity wins), matching how the
+    /// private-chat coordinators consolidate on open.
+    private func buildRecentChatRows(
+        meshRows: [MeshPeerRow],
+        geohashPeople: [GeohashPersonRow]
+    ) -> [RecentChatRow] {
+        // A conversation can be keyed by the stable Noise peer ID while the
+        // roster lists the ephemeral one — compare fingerprints too.
+        var visibleIdentities = Set<String>()
+        for row in meshRows {
+            visibleIdentities.insert(row.peerID.id)
+            if let fingerprint = chatViewModel.getFingerprint(for: row.peerID) {
+                visibleIdentities.insert(fingerprint)
+            }
+        }
+        // Someone visible in the geohash section must not also get a chat
+        // row: their GeoDM conversation is keyed by the nostr_ form of the
+        // same pubkey the roster lists.
+        for person in geohashPeople {
+            visibleIdentities.insert(PeerID(nostr_: person.id).id)
+        }
+
+        struct Candidate {
+            let peerID: PeerID
+            let lastActivity: Date
+        }
+        var bestByIdentity: [String: Candidate] = [:]
+
+        for (id, conversation) in conversations.conversationsByID {
+            guard case .direct(let handle) = id else { continue }
+            let peerID = handle.routingPeerID
+            // Groups have their own section; blocked people get no row.
+            guard !peerID.isGroup else { continue }
+            guard let lastMessage = conversation.messages.last else { continue }
+            guard !chatViewModel.isPeerBlocked(peerID) else { continue }
+
+            let fingerprint = chatViewModel.getFingerprint(for: peerID)
+            if visibleIdentities.contains(peerID.id) { continue }
+            if let fingerprint, visibleIdentities.contains(fingerprint) { continue }
+
+            let identityKey = fingerprint ?? peerID.id
+            if let existing = bestByIdentity[identityKey],
+               existing.lastActivity >= lastMessage.timestamp {
+                continue
+            }
+            bestByIdentity[identityKey] = Candidate(peerID: peerID, lastActivity: lastMessage.timestamp)
+        }
+
+        return bestByIdentity.values
+            .sorted { $0.lastActivity > $1.lastActivity }
+            .map { candidate in
+                RecentChatRow(
+                    peerID: candidate.peerID,
+                    displayName: displayName(for: candidate.peerID),
+                    hasUnread: chatViewModel.hasUnreadMessages(for: candidate.peerID),
+                    lastActivity: candidate.lastActivity
+                )
+            }
+    }
+
+    /// GeoDM conversations resolve through the Nostr mapping —
+    /// `resolveNickname` only consults mesh identity sources and would
+    /// render a `nostr_…` key as an opaque `anonnost` fallback.
+    private func displayName(for peerID: PeerID) -> String {
+        if peerID.isGeoDM {
+            return chatViewModel.geohashDisplayName(for: peerID)
+        }
+        return chatViewModel.resolveNickname(for: peerID)
+    }
+
+    private static func changedConversationID(_ change: ConversationChange) -> ConversationID {
+        switch change {
+        case .appended(let id, _),
+             .updated(let id, _),
+             .statusChanged(let id, _, _),
+             .messageRemoved(let id, _),
+             .cleared(let id),
+             .removed(let id),
+             .unreadChanged(let id, _):
+            return id
+        case .migrated(_, let to):
+            return to
+        }
+    }
+
+    private func buildGroupRows() -> [GroupChatRow] {
+        let myFingerprint = chatViewModel.meshService.noiseIdentityFingerprint()
+        return chatViewModel.groupStore.groups.map { group in
+            GroupChatRow(
+                peerID: group.peerID,
+                name: group.name,
+                memberCount: group.members.count,
+                isCreator: group.creatorFingerprint == myFingerprint,
+                hasUnread: chatViewModel.hasUnreadMessages(for: group.peerID)
+            )
+        }
+    }
+
     private func buildGeohashPeople() -> [GeohashPersonRow] {
         let myHex = currentGeohashIdentityHex()
         let teleportedSet = Set(locationPresenceStore.teleportedGeo.map { $0.lowercased() })

bitchat/App/PrivacyScreen.swift

@@ -0,0 +1,100 @@
+//
+// PrivacyScreen.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
+
+/// Covers the window while the app is not frontmost, so the snapshot iOS takes
+/// for the app switcher shows a placeholder instead of the open conversation.
+///
+/// The cover is added on `willResignActive` and removed on `didBecomeActive`.
+/// Both are deliberately UIKit notifications rather than SwiftUI's `scenePhase`:
+/// the snapshot is captured shortly after `willResignActive`, and adding an
+/// opaque subview to the window synchronously in that callback is the only way
+/// to guarantee it is in the render tree before the capture. A SwiftUI overlay
+/// driven by state may not have been laid out yet.
+///
+/// Panic wipe separately deletes any snapshots already on disk; this keeps new
+/// ones from containing anything worth deleting.
+final class PrivacyScreen {
+    static let shared = PrivacyScreen()
+
+    private var cover: UIView?
+    private var observers: [NSObjectProtocol] = []
+
+    private init() {}
+
+    /// Idempotent: repeated calls do not stack observers.
+    ///
+    /// `queue: nil` is required, not incidental. Passing an `OperationQueue`
+    /// would enqueue the handler to run in a later runloop turn, which the
+    /// snapshot can beat; with no queue the block runs synchronously on the
+    /// thread that posted the notification — the main thread, for UIApplication
+    /// lifecycle notifications.
+    func install() {
+        guard observers.isEmpty else { return }
+        let center = NotificationCenter.default
+        observers = [
+            center.addObserver(
+                forName: UIApplication.willResignActiveNotification,
+                object: nil,
+                queue: nil
+            ) { _ in
+                PrivacyScreen.shared.show()
+            },
+            center.addObserver(
+                forName: UIApplication.didBecomeActiveNotification,
+                object: nil,
+                queue: nil
+            ) { _ in
+                PrivacyScreen.shared.hide()
+            }
+        ]
+    }
+
+    private func show() {
+        guard cover == nil, let window = Self.activeWindow() else { return }
+
+        // Opaque rather than a blur: blurred large text can stay partly
+        // legible, and the snapshot is stored on disk.
+        let view = UIView(frame: window.bounds)
+        view.backgroundColor = .systemBackground
+        view.autoresizingMask = [.flexibleWidth, .flexibleHeight]
+
+        let label = UILabel()
+        label.text = "bitchat"
+        label.font = .monospacedSystemFont(ofSize: 22, weight: .medium)
+        label.textColor = .secondaryLabel
+        label.translatesAutoresizingMaskIntoConstraints = false
+        view.addSubview(label)
+        NSLayoutConstraint.activate([
+            label.centerXAnchor.constraint(equalTo: view.centerXAnchor),
+            label.centerYAnchor.constraint(equalTo: view.centerYAnchor)
+        ])
+
+        window.addSubview(view)
+        cover = view
+    }
+
+    private func hide() {
+        cover?.removeFromSuperview()
+        cover = nil
+    }
+
+    private static func activeWindow() -> UIWindow? {
+        UIApplication.shared.connectedScenes
+            .compactMap { $0 as? UIWindowScene }
+            .flatMap(\.windows)
+            .first { $0.isKeyWindow } ??
+        UIApplication.shared.connectedScenes
+            .compactMap { $0 as? UIWindowScene }
+            .flatMap(\.windows)
+            .first
+    }
+}
+#endif

bitchat/App/PrivateConversationModels.swift

@@ -108,7 +108,13 @@ struct PrivateConversationHeaderState: Equatable {
     let encryptionStatus: EncryptionStatus?
 
     var supportsFavoriteToggle: Bool {
-        !conversationPeerID.isGeoDM
+        !conversationPeerID.isGeoDM && !conversationPeerID.isGroup
+    }
+
+    /// Group chats have no single peer identity behind the header: no
+    /// fingerprint screen, no per-peer encryption badge.
+    var isGroupConversation: Bool {
+        conversationPeerID.isGroup
     }
 }
 
@@ -206,6 +212,13 @@ final class PrivateConversationModel: ObservableObject {
             }
             .store(in: &cancellables)
 
+        chatViewModel.groupStore.$groups
+            .receive(on: DispatchQueue.main)
+            .sink { [weak self] _ in
+                self?.refreshSelectedConversation()
+            }
+            .store(in: &cancellables)
+
         NotificationCenter.default.publisher(for: Notification.Name("peerStatusUpdated"))
             .receive(on: DispatchQueue.main)
             .sink { [weak self] _ in
@@ -229,10 +242,36 @@ final class PrivateConversationModel: ObservableObject {
     }
 
     private func makeHeaderState(for conversationPeerID: PeerID) -> PrivateConversationHeaderState {
+        // Group chats: the "peer" is the whole crew. Name + member count in
+        // the header; availability reads as mesh since group traffic floods
+        // the local mesh, and the per-peer encryption badge does not apply.
+        if conversationPeerID.isGroup {
+            let displayName: String
+            if let group = chatViewModel.groupStore.group(for: conversationPeerID) {
+                displayName = "#\(group.name) (\(group.members.count))"
+            } else {
+                displayName = String(localized: "common.unknown", comment: "Fallback label for unknown peer")
+            }
+            return PrivateConversationHeaderState(
+                conversationPeerID: conversationPeerID,
+                headerPeerID: conversationPeerID,
+                displayName: displayName,
+                availability: .meshReachable,
+                isFavorite: false,
+                encryptionStatus: nil
+            )
+        }
+
         let headerPeerID = chatViewModel.getShortIDForNoiseKey(conversationPeerID)
         let peer = chatViewModel.getPeer(byID: headerPeerID)
         let displayName = resolveDisplayName(for: conversationPeerID, headerPeerID: headerPeerID, peer: peer)
-        let availability = resolveAvailability(for: headerPeerID, peer: peer)
+        // Geo DMs are always routed through BitChat private envelopes over
+        // Nostr; their nostr_ keys never resolve to a reachable mesh peer, so
+        // resolveAvailability would report .offline. Report .nostrAvailable
+        // so the header shows the globe instead of a misleading "offline" tag.
+        let availability = conversationPeerID.isGeoDM
+            ? .nostrAvailable
+            : resolveAvailability(for: headerPeerID, peer: peer)
         let encryptionStatus: EncryptionStatus? = conversationPeerID.isGeoDM
             ? nil
             : chatViewModel.getEncryptionStatus(for: headerPeerID)
@@ -255,6 +294,21 @@ final class PrivateConversationModel: ObservableObject {
         if conversationPeerID.isGeoDM, case .location(let channel) = locationChannelsModel.selectedChannel {
             return "#\(channel.geohash)/@\(chatViewModel.geohashDisplayName(for: conversationPeerID))"
         }
+        // Local alias wins over a live peer row's announced nickname.
+        if headerPeerID.id.count == 16 {
+            let candidates = chatViewModel.identityManager.getCryptoIdentitiesByPeerIDPrefix(headerPeerID)
+            if let identity = candidates.first,
+               let social = chatViewModel.identityManager.getSocialIdentity(for: identity.fingerprint),
+               let pet = social.localPetname, !pet.isEmpty {
+                return pet
+            }
+        } else if let noiseKey = headerPeerID.noiseKey {
+            let fingerprint = noiseKey.sha256Fingerprint()
+            if let social = chatViewModel.identityManager.getSocialIdentity(for: fingerprint),
+               let pet = social.localPetname, !pet.isEmpty {
+                return pet
+            }
+        }
         if let displayName = peer?.displayName {
             return displayName
         }
@@ -269,23 +323,15 @@ final class PrivateConversationModel: ObservableObject {
         if headerPeerID.id.count == 16 {
             let candidates = chatViewModel.identityManager.getCryptoIdentitiesByPeerIDPrefix(headerPeerID)
             if let identity = candidates.first,
-               let social = chatViewModel.identityManager.getSocialIdentity(for: identity.fingerprint) {
-                if let pet = social.localPetname, !pet.isEmpty {
-                    return pet
-                }
-                if !social.claimedNickname.isEmpty {
-                    return social.claimedNickname
-                }
+               let social = chatViewModel.identityManager.getSocialIdentity(for: identity.fingerprint),
+               !social.claimedNickname.isEmpty {
+                return social.claimedNickname
             }
         } else if let noiseKey = headerPeerID.noiseKey {
             let fingerprint = noiseKey.sha256Fingerprint()
-            if let social = chatViewModel.identityManager.getSocialIdentity(for: fingerprint) {
-                if let pet = social.localPetname, !pet.isEmpty {
-                    return pet
-                }
-                if !social.claimedNickname.isEmpty {
-                    return social.claimedNickname
-                }
+            if let social = chatViewModel.identityManager.getSocialIdentity(for: fingerprint),
+               !social.claimedNickname.isEmpty {
+                return social.claimedNickname
             }
         }
 
@@ -311,7 +357,10 @@ final class PrivateConversationModel: ObservableObject {
         }
         if let noiseKey = Data(hexString: headerPeerID.id),
            let favoriteStatus = FavoritesPersistenceService.shared.getFavoriteStatus(for: noiseKey),
-           favoriteStatus.isMutual {
+           favoriteStatus.isMutual,
+           // No stored recipient key means no Nostr delivery — and the
+           // "end-to-end encrypted" caption keys off .nostrAvailable.
+           favoriteStatus.peerNostrPublicKey != nil {
             return .nostrAvailable
         }
         if chatViewModel.meshService.isPeerConnected(headerPeerID) || chatViewModel.connectedPeers.contains(headerPeerID) {

bitchat/App/SharedContentImportModel.swift

@@ -0,0 +1,119 @@
+import BitFoundation
+import Combine
+import Foundation
+
+enum SharedContentDestination: Sendable, Equatable {
+    case mesh
+    case geohash(String)
+    case privateConversation(peerID: PeerID, displayName: String)
+
+    static func resolve(
+        selectedPrivatePeerID: PeerID?,
+        privateDisplayName: String?,
+        activeChannel: ChannelID
+    ) -> SharedContentDestination {
+        if let selectedPrivatePeerID {
+            let fallback = String(selectedPrivatePeerID.id.prefix(12))
+            return .privateConversation(
+                peerID: selectedPrivatePeerID,
+                displayName: privateDisplayName?.trimmedOrNilIfEmpty ?? fallback
+            )
+        }
+
+        switch activeChannel {
+        case .mesh:
+            return .mesh
+        case .location(let channel):
+            return .geohash(channel.geohash.lowercased())
+        }
+    }
+
+    var displayName: String {
+        switch self {
+        case .mesh:
+            return "#mesh"
+        case .geohash(let geohash):
+            return "#\(geohash)"
+        case .privateConversation(_, let displayName):
+            return displayName
+        }
+    }
+}
+
+struct SharedContentOffer: Identifiable, Sendable, Equatable {
+    let payload: SharedContentPayload
+    let destination: SharedContentDestination
+
+    var id: UUID { payload.id }
+}
+
+/// Holds a pending extension handoff until the user chooses a destination and
+/// explicitly adds it to the composer. This type has no send dependency by
+/// design: confirming an import can never transmit a message.
+@MainActor
+final class SharedContentImportModel: ObservableObject {
+    @Published private(set) var offer: SharedContentOffer?
+
+    private let store: SharedContentStore?
+
+    init(store: SharedContentStore?) {
+        self.store = store
+    }
+
+    @discardableResult
+    func refresh(
+        destination: SharedContentDestination,
+        now: Date = Date()
+    ) -> SharedContentPayload? {
+        guard let payload = store?.pending(now: now) else {
+            offer = nil
+            return nil
+        }
+
+        let nextOffer = SharedContentOffer(payload: payload, destination: destination)
+        if offer != nextOffer {
+            offer = nextOffer
+        }
+        return payload
+    }
+
+    func updateDestination(_ destination: SharedContentDestination) {
+        guard let offer, offer.destination != destination else { return }
+        self.offer = SharedContentOffer(payload: offer.payload, destination: destination)
+    }
+
+    /// Returns composer text only when the currently displayed destination is
+    /// still current and the reviewed envelope is still the stored envelope.
+    /// A destination change updates the prompt and requires another tap.
+    func confirm(
+        destination: SharedContentDestination,
+        now: Date = Date()
+    ) -> String? {
+        guard let offer else { return nil }
+        guard offer.destination == destination else {
+            updateDestination(destination)
+            return nil
+        }
+        guard let payload = store?.consume(id: offer.id, now: now) else {
+            _ = refresh(destination: destination, now: now)
+            return nil
+        }
+
+        self.offer = nil
+        return payload.composerText
+    }
+
+    func cancel(destination: SharedContentDestination, now: Date = Date()) {
+        guard let offer else { return }
+        store?.discard(id: offer.id)
+        self.offer = nil
+        // If a newer share replaced the reviewed envelope, surface it rather
+        // than losing it with the older cancellation.
+        _ = refresh(destination: destination, now: now)
+    }
+
+    func discardAll() {
+        store?.discardAll()
+        offer = nil
+    }
+}

bitchat/App/VerificationModel.swift

@@ -3,16 +3,31 @@ import Combine
 import Foundation
 
 struct FingerprintPresentationState: Equatable {
-    let statusPeerID: PeerID
     let peerNickname: String
     let encryptionStatus: EncryptionStatus
     let theirFingerprint: String?
     let myFingerprint: String
     let isVerified: Bool
+    /// User-assigned local alias (petname), if any — distinct from the
+    /// peer-claimed nickname.
+    let localPetname: String?
+    /// Number of currently-valid vouches from peers the user verified
+    /// (0 when the peer is explicitly verified — the stronger badge wins).
+    let voucherCount: Int
+    /// Display names of the (verified) vouchers, where known.
+    let voucherNames: [String]
+
+    /// Vouched for by ≥1 peer the user verified (and not explicitly verified).
+    var isVouched: Bool { voucherCount > 0 }
 
     var canToggleVerification: Bool {
         encryptionStatus == .noiseSecured || encryptionStatus == .noiseVerified
     }
+
+    /// Alias field is editable once we know who we're looking at.
+    var canEditLocalAlias: Bool {
+        theirFingerprint != nil
+    }
 }
 
 enum VerificationScanOutcome: Equatable {
@@ -48,10 +63,6 @@ final class VerificationModel: ObservableObject {
         return VerificationService.shared.buildMyQRString(nickname: currentNickname, npub: npub) ?? ""
     }
 
-    func beginQRVerification(with qr: VerificationService.VerificationQR) -> Bool {
-        chatViewModel.beginQRVerification(with: qr)
-    }
-
     func verifyScannedPayload(_ payload: String) -> VerificationScanOutcome {
         guard let qr = VerificationService.shared.verifyScannedQR(payload) else {
             return .invalid
@@ -72,6 +83,46 @@ final class VerificationModel: ObservableObject {
         chatViewModel.unverifyFingerprint(for: peerID)
     }
 
+    /// Persist a local alias for this peer. Empty/whitespace clears it so the
+    /// claimed nickname shows again. Display paths prefer `localPetname`
+    /// when set (#1439).
+    func setLocalPetname(_ petname: String?, for peerID: PeerID) {
+        let statusPeerID = chatViewModel.getShortIDForNoiseKey(peerID)
+        guard let fingerprint = chatViewModel.getFingerprint(for: statusPeerID) else { return }
+
+        let trimmed = petname?.trimmingCharacters(in: .whitespacesAndNewlines)
+        let normalized: String? = (trimmed?.isEmpty == false) ? trimmed : nil
+
+        let existing = chatViewModel.identityManager.getSocialIdentity(for: fingerprint)
+        let claimed = existing?.claimedNickname
+            ?? chatViewModel.meshService.peerNickname(peerID: statusPeerID)
+            ?? chatViewModel.resolveNickname(for: statusPeerID)
+        var identity = existing ?? SocialIdentity(
+            fingerprint: fingerprint,
+            localPetname: nil,
+            claimedNickname: claimed,
+            trustLevel: .unknown,
+            isFavorite: false,
+            isBlocked: false,
+            notes: nil
+        )
+        identity.localPetname = normalized
+        // Prefer the mesh-announced name for claimedNickname so we don't
+        // persist a previous alias as the "claimed" identity.
+        if let announced = chatViewModel.meshService.peerNickname(peerID: statusPeerID),
+           !announced.isEmpty {
+            identity.claimedNickname = announced
+        } else if identity.claimedNickname.isEmpty {
+            identity.claimedNickname = claimed
+        }
+        chatViewModel.identityManager.updateSocialIdentity(identity)
+        // Rebuild peer rows so PeerList / DM header pick up the new display name
+        // without waiting for an unrelated mesh event.
+        chatViewModel.unifiedPeerService.refreshPeers()
+        NotificationCenter.default.post(name: Notification.Name("peerStatusUpdated"), object: nil)
+        objectWillChange.send()
+    }
+
     func isVerified(peerID: PeerID) -> Bool {
         guard let fingerprint = chatViewModel.getFingerprint(for: peerID) else { return false }
         return peerIdentityStore.isVerified(fingerprint)
@@ -82,14 +133,36 @@ final class VerificationModel: ObservableObject {
         let encryptionStatus = chatViewModel.getEncryptionStatus(for: statusPeerID)
         let theirFingerprint = chatViewModel.getFingerprint(for: statusPeerID)
         let peerNickname = resolveDisplayName(for: peerID, statusPeerID: statusPeerID)
+        let isVerified = theirFingerprint.map { peerIdentityStore.isVerified($0) } ?? false
+        let localPetname = theirFingerprint
+            .flatMap { chatViewModel.identityManager.getSocialIdentity(for: $0)?.localPetname }
+
+        // Vouch state is recomputed on read: only vouchers still in the
+        // verified set count, so removing a verification silently retires the
+        // vouches that peer gave.
+        let vouchers: [VouchRecord]
+        if !isVerified, let theirFingerprint {
+            vouchers = chatViewModel.identityManager.validVouchers(for: theirFingerprint)
+        } else {
+            vouchers = []
+        }
+        let voucherNames = vouchers.compactMap { record -> String? in
+            guard let social = chatViewModel.identityManager.getSocialIdentity(for: record.voucherFingerprint) else {
+                return nil
+            }
+            if let petname = social.localPetname, !petname.isEmpty { return petname }
+            return social.claimedNickname.isEmpty ? nil : social.claimedNickname
+        }
 
         return FingerprintPresentationState(
-            statusPeerID: statusPeerID,
             peerNickname: peerNickname,
             encryptionStatus: encryptionStatus,
             theirFingerprint: theirFingerprint,
             myFingerprint: chatViewModel.getMyFingerprint(),
-            isVerified: theirFingerprint.map { peerIdentityStore.isVerified($0) } ?? false
+            isVerified: isVerified,
+            localPetname: localPetname,
+            voucherCount: vouchers.count,
+            voucherNames: voucherNames
         )
     }
 
@@ -122,9 +195,29 @@ final class VerificationModel: ObservableObject {
                 self?.objectWillChange.send()
             }
             .store(in: &cancellables)
+
+        // Vouch state changes (ChatVouchCoordinator.notifyPeerTrustChanged)
+        // are signalled via this notification rather than a published
+        // property, so an open fingerprint sheet refreshes its vouched badge
+        // live when a vouch batch is accepted.
+        NotificationCenter.default.publisher(for: Notification.Name("peerStatusUpdated"))
+            .receive(on: DispatchQueue.main)
+            .sink { [weak self] _ in
+                self?.objectWillChange.send()
+            }
+            .store(in: &cancellables)
     }
 
     private func resolveDisplayName(for peerID: PeerID, statusPeerID: PeerID) -> String {
+        // Prefer an explicit local alias even when a live peer row exists —
+        // peer.displayName already does this once UnifiedPeerService rebuilds,
+        // but read social identity directly so the fingerprint sheet header
+        // updates before that rebuild lands.
+        if let fingerprint = chatViewModel.getFingerprint(for: statusPeerID),
+           let pet = chatViewModel.identityManager.getSocialIdentity(for: fingerprint)?.localPetname,
+           !pet.isEmpty {
+            return pet
+        }
         if let peer = chatViewModel.getPeer(byID: statusPeerID) {
             return peer.displayName
         }
@@ -138,9 +231,6 @@ final class VerificationModel: ObservableObject {
             }
             let fingerprint = data.sha256Fingerprint()
             if let social = chatViewModel.identityManager.getSocialIdentity(for: fingerprint) {
-                if let pet = social.localPetname, !pet.isEmpty {
-                    return pet
-                }
                 if !social.claimedNickname.isEmpty {
                     return social.claimedNickname
                 }

bitchat/Assets.xcassets/AppIconDebug.appiconset/Contents.json

@@ -27,6 +27,66 @@
       "idiom" : "universal",
       "platform" : "ios",
       "size" : "1024x1024"
+    },
+    {
+      "filename" : "mac_16x16.png",
+      "idiom" : "mac",
+      "scale" : "1x",
+      "size" : "16x16"
+    },
+    {
+      "filename" : "mac_16x16@2x.png",
+      "idiom" : "mac",
+      "scale" : "2x",
+      "size" : "16x16"
+    },
+    {
+      "filename" : "mac_32x32.png",
+      "idiom" : "mac",
+      "scale" : "1x",
+      "size" : "32x32"
+    },
+    {
+      "filename" : "mac_32x32@2x.png",
+      "idiom" : "mac",
+      "scale" : "2x",
+      "size" : "32x32"
+    },
+    {
+      "filename" : "mac_128x128.png",
+      "idiom" : "mac",
+      "scale" : "1x",
+      "size" : "128x128"
+    },
+    {
+      "filename" : "mac_128x128@2x.png",
+      "idiom" : "mac",
+      "scale" : "2x",
+      "size" : "128x128"
+    },
+    {
+      "filename" : "mac_256x256.png",
+      "idiom" : "mac",
+      "scale" : "1x",
+      "size" : "256x256"
+    },
+    {
+      "filename" : "mac_256x256@2x.png",
+      "idiom" : "mac",
+      "scale" : "2x",
+      "size" : "256x256"
+    },
+    {
+      "filename" : "mac_512x512.png",
+      "idiom" : "mac",
+      "scale" : "1x",
+      "size" : "512x512"
+    },
+    {
+      "filename" : "mac_512x512@2x.png",
+      "idiom" : "mac",
+      "scale" : "2x",
+      "size" : "512x512"
     }
   ],
   "info" : {

bitchat/BitchatApp.swift

@@ -40,6 +40,8 @@ struct BitchatApp: App {
                 .environmentObject(runtime.locationChannelsModel)
                 .environmentObject(runtime.peerListModel)
                 .environmentObject(runtime.appChromeModel)
+                .environmentObject(runtime.boardAlertsModel)
+                .environmentObject(runtime.sharedContentImportModel)
                 .onAppear {
                     appDelegate.runtime = runtime
                     runtime.start()
@@ -71,8 +73,11 @@ struct BitchatApp: App {
 final class AppDelegate: NSObject, UIApplicationDelegate {
     weak var runtime: AppRuntime?
 
-    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey : Any]? = nil) -> Bool {
-        true
+    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]? = nil) -> Bool {
+        // Installed before the first resign-active so the app-switcher snapshot
+        // never captures an open conversation.
+        PrivacyScreen.shared.install()
+        return true
     }
 
     func applicationWillTerminate(_ application: UIApplication) {
@@ -103,12 +108,20 @@ final class NotificationDelegate: NSObject, UNUserNotificationCenterDelegate {
 
     func userNotificationCenter(_ center: UNUserNotificationCenter, didReceive response: UNNotificationResponse, withCompletionHandler completionHandler: @escaping () -> Void) {
         let identifier = response.notification.request.identifier
+        let actionIdentifier = response.actionIdentifier
         let userInfo = response.notification.request.content.userInfo
 
+        // Complete only after the response is handled: for a background
+        // action (👋 wave) the system may suspend the app the moment the
+        // completion handler runs, which would drop the queued send.
         Task { @MainActor in
-            self.runtime?.handleNotificationResponse(identifier: identifier, userInfo: userInfo)
+            self.runtime?.handleNotificationResponse(
+                identifier: identifier,
+                actionIdentifier: actionIdentifier,
+                userInfo: userInfo
+            )
+            completionHandler()
         }
-        completionHandler()
     }
 
     func userNotificationCenter(_ center: UNUserNotificationCenter, willPresent notification: UNNotification, withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void) {

bitchat/Features/media/ImageUtils.swift

@@ -206,7 +206,7 @@ enum ImageUtils {
         } else {
             directory = try applicationFilesDirectory().appendingPathComponent("images/outgoing", isDirectory: true)
         }
-        try FileManager.default.createDirectory(at: directory, withIntermediateDirectories: true, attributes: nil)
+        try FileManager.default.createDirectory(at: directory, withIntermediateDirectories: true, attributes: BLEIncomingFileStore.mediaProtectionAttributes)
         return directory.appendingPathComponent(fileName)
     }
 

bitchat/Features/voice/AudioSessionCoordinator.swift

@@ -0,0 +1,472 @@
+//
+// AudioSessionCoordinator.swift
+// bitchat
+//
+// This is free and unencumbered software released into the public domain.
+// For more information, see <https://unlicense.org>
+//
+
+import AVFoundation
+import BitLogger
+import Foundation
+
+/// The raw audio-session calls the coordinator makes, abstracted so the
+/// state machine is unit-testable with a mock (and compiles on the macOS
+/// test host, where `AVAudioSession` doesn't exist).
+///
+/// Calls arrive on the coordinator's private serial queue — never the main
+/// thread. `setCategory`/`setActive` block on IPC to the audio server
+/// (observed >1 s under contention on device, tripping the system gesture
+/// gate), and Apple explicitly recommends activating the session off the
+/// main thread.
+protocol SessionApplying: Sendable {
+    func setCategory(_ category: AudioSessionCoordinator.Category) throws
+    func setActive(_ active: Bool, notifyOthersOnDeactivation: Bool) throws
+}
+
+/// Sole owner of `AVAudioSession` category/activation for voice features.
+///
+/// Talk-over means capture (push-to-talk) and playback (inbound bursts,
+/// voice notes) can be live simultaneously; letting each engine configure
+/// the shared session directly made them stomp each other's category and
+/// route mid-flight (the AURemoteIO -10851 dead-input class). Instead every
+/// client acquires a `Token` and the coordinator:
+///
+/// - reference-counts activation: `setActive(true)` only on the first
+///   holder, `setActive(false, notifyOthersOnDeactivation:)` only when the
+///   last one releases — no client can deactivate another's session;
+/// - keeps one escalating category: playback-only holders get `.playback`,
+///   any capture holder escalates to `.playAndRecord`, and the category is
+///   never downgraded while anyone still holds a token (capture ending must
+///   not yank the route out from under live playback);
+/// - fans out `onInterrupted` on system interruptions and when the active
+///   route's device disappears (no auto-resume: bursts are transient, the
+///   next press or burst simply re-acquires). The escalating category change
+///   fans out separately as `onCategoryEscalated` — the session stays live,
+///   so holders that can rebuild their engine against the new configuration
+///   keep playing (talk-over is bidirectional); holders that don't provide
+///   it fall back to `onInterrupted`.
+///
+/// Threading: all state lives on a private serial queue, which both
+/// serializes rapid acquire/release pairs and keeps the blocking session IPC
+/// off the main thread (`acquire` is `async` for exactly that hop; `release`
+/// is fire-and-forget onto the queue). Holder callbacks always run on the
+/// main actor.
+///
+/// Microphone *permission* queries stay with their callers; this type owns
+/// only category and activation.
+///
+/// `@unchecked Sendable`: every mutable property is confined to `queue`.
+final class AudioSessionCoordinator: @unchecked Sendable {
+    enum Use {
+        case playback
+        case capture
+    }
+
+    /// The session category the coordinator has applied (the `SessionApplying`
+    /// adapter maps these to concrete `AVAudioSession` category/mode/options).
+    enum Category {
+        case playback
+        case playAndRecord
+    }
+
+    /// Opaque handle for one client's hold on the session. Release exactly
+    /// once when done (extra releases are ignored).
+    ///
+    /// `@unchecked` because the stored callbacks are `@MainActor`-isolated
+    /// closures (non-Sendable as stored types). Lifecycle state is protected
+    /// by `stateLock`, and callbacks are only ever invoked on the main actor.
+    final class Token: @unchecked Sendable {
+        fileprivate enum CallbackKind: Sendable {
+            case interrupted
+            case categoryEscalated
+        }
+
+        /// A callback snapshot is only valid for the lifecycle epoch in which
+        /// it was captured. `release` advances the epoch synchronously before
+        /// its queue work, so a callback already headed to the main actor can't
+        /// reach a client that has since released this token and reacquired a
+        /// different one.
+        fileprivate struct CallbackTicket: Sendable {
+            let token: Token
+            let kind: CallbackKind
+            let lifecycleEpoch: UInt64
+        }
+
+        private enum Lifecycle {
+            /// Registered on the session queue, but `acquire` has not yet
+            /// returned into the client's main-actor call frame.
+            case acquiring
+            case ready
+            case released
+        }
+
+        fileprivate let onInterrupted: @MainActor () -> Void
+        fileprivate let onCategoryEscalated: (@MainActor () -> Void)?
+        private let stateLock = NSLock()
+        private var lifecycle = Lifecycle.acquiring
+        private var lifecycleEpoch: UInt64 = 0
+        /// A terminal event that lands while the token is registered but not
+        /// yet handed off invalidates the acquire before its caller can start.
+        private var terminalEventPendingHandoff = false
+
+        fileprivate init(
+            onInterrupted: @escaping @MainActor () -> Void,
+            onCategoryEscalated: (@MainActor () -> Void)?
+        ) {
+            self.onInterrupted = onInterrupted
+            self.onCategoryEscalated = onCategoryEscalated
+        }
+
+        /// Records an event at the same linearization point at which the
+        /// coordinator snapshots its holders. An acquiring token cannot safely
+        /// receive a callback yet: terminal events invalidate the acquire,
+        /// while category escalation needs no callback because its engine will
+        /// start against the already-escalated configuration.
+        fileprivate func record(_ kind: CallbackKind) -> CallbackTicket? {
+            stateLock.withLock {
+                switch lifecycle {
+                case .acquiring:
+                    switch kind {
+                    case .interrupted:
+                        terminalEventPendingHandoff = true
+                    case .categoryEscalated:
+                        break
+                    }
+                    return nil
+                case .ready:
+                    return CallbackTicket(token: self, kind: kind, lifecycleEpoch: lifecycleEpoch)
+                case .released:
+                    return nil
+                }
+            }
+        }
+
+        /// Completes the main-actor ownership handoff if no terminal event
+        /// invalidated it. Because `acquire` itself is main-actor isolated, a
+        /// successful handoff returns directly into the caller without another
+        /// actor hop; no callback can interleave before the caller stores the
+        /// returned token.
+        fileprivate func completeHandoff() -> Bool {
+            stateLock.withLock {
+                guard lifecycle == .acquiring,
+                      !terminalEventPendingHandoff
+                else { return false }
+                lifecycle = .ready
+                return true
+            }
+        }
+
+        /// Marks the token dead synchronously, before the asynchronous holder
+        /// removal. Returns false for an already-released token.
+        fileprivate func markReleased() -> Bool {
+            stateLock.withLock {
+                guard lifecycle != .released else { return false }
+                lifecycle = .released
+                lifecycleEpoch &+= 1
+                terminalEventPendingHandoff = false
+                return true
+            }
+        }
+
+        /// Revalidates a queue snapshot at the main-actor delivery boundary.
+        /// The lock is deliberately released before invoking client code: real
+        /// callbacks commonly call `release` on this same token.
+        @MainActor
+        fileprivate func deliver(_ ticket: CallbackTicket) {
+            let isLive = stateLock.withLock {
+                lifecycle == .ready && lifecycleEpoch == ticket.lifecycleEpoch
+            }
+            guard isLive else { return }
+            switch ticket.kind {
+            case .interrupted:
+                onInterrupted()
+            case .categoryEscalated:
+                (onCategoryEscalated ?? onInterrupted)()
+            }
+        }
+    }
+
+    /// Deterministic suspension points for lifecycle race tests. Production
+    /// instances use the nil defaults; the hooks never move session calls off
+    /// the coordinator queue or callback execution off the main actor.
+    struct TestingHooks: Sendable {
+        let beforeAcquireHandoff: (@Sendable () async -> Void)?
+        let beforeCallbackDelivery: (@Sendable () async -> Void)?
+
+        init(
+            beforeAcquireHandoff: (@Sendable () async -> Void)? = nil,
+            beforeCallbackDelivery: (@Sendable () async -> Void)? = nil
+        ) {
+            self.beforeAcquireHandoff = beforeAcquireHandoff
+            self.beforeCallbackDelivery = beforeCallbackDelivery
+        }
+    }
+
+    static let shared = AudioSessionCoordinator(session: SystemAudioSession())
+
+    private let session: SessionApplying
+    private let testingHooks: TestingHooks
+    /// Confines all mutable state, serializes whole acquire/release
+    /// operations (two rapid presses can't interleave their category and
+    /// activation calls), and hosts the blocking session IPC off main.
+    private let queue = DispatchQueue(label: "chat.bitchat.audio-session", qos: .userInitiated)
+
+    // Queue-confined state.
+    private var holders: [ObjectIdentifier: Token] = [:]
+    private var currentCategory: Category?
+    private var sessionActive = false
+    /// Written once in init, read in deinit — never touched concurrently.
+    private var observers: [NSObjectProtocol] = []
+
+    init(session: SessionApplying, testingHooks: TestingHooks = TestingHooks()) {
+        self.session = session
+        self.testingHooks = testingHooks
+        observeSystemNotifications()
+    }
+
+    deinit {
+        for observer in observers {
+            NotificationCenter.default.removeObserver(observer)
+        }
+    }
+
+    /// Configures + activates the session for `use` and registers the caller
+    /// as a holder. The blocking `AVAudioSession` calls run on the session
+    /// queue — the caller suspends instead of stalling its thread (a PTT
+    /// press used to block main >1 s in `setActive`, tripping the system
+    /// gesture gate). `onInterrupted` fires (on the main actor) when the
+    /// client must stop using the session: a system interruption began or
+    /// its route's device went away. The client should stop its engine,
+    /// finalize any artifacts, and release — resuming means acquiring again.
+    ///
+    /// `onCategoryEscalated` fires instead when the session category
+    /// escalated underneath the holder (a capture client joined): the session
+    /// stays active, so a holder that can rebuild its engine against the new
+    /// configuration should restart and keep going. Holders that pass `nil`
+    /// get `onInterrupted` for escalation too. Escalation is delivered before
+    /// `acquire` returns, so the new holder starts its engine strictly after
+    /// existing ones were told to rebuild. Main-actor isolation is also the
+    /// ownership handoff boundary: if interruption or route loss lands after
+    /// queue registration but before that boundary, the provisional holder is
+    /// removed and `acquire` throws `CancellationError` instead of returning a
+    /// token whose callback already fired.
+    @MainActor
+    func acquire(
+        _ use: Use,
+        onInterrupted: @escaping @MainActor () -> Void,
+        onCategoryEscalated: (@MainActor () -> Void)? = nil
+    ) async throws -> Token {
+        let token = Token(onInterrupted: onInterrupted, onCategoryEscalated: onCategoryEscalated)
+        let reconfigured: [Token.CallbackTicket] = try await withCheckedThrowingContinuation { continuation in
+            queue.async {
+                do {
+                    continuation.resume(returning: try self.activateOnQueue(use, registering: token))
+                } catch {
+                    continuation.resume(throwing: error)
+                }
+            }
+        }
+
+        // Escalating playback -> playAndRecord reconfigures the hardware
+        // route; engines started against the old configuration must restart.
+        if !reconfigured.isEmpty {
+            SecureLogger.info("AudioSession: category escalated to playAndRecord with \(reconfigured.count) live holder(s)", category: .session)
+            await deliver(reconfigured)
+        }
+        if let beforeAcquireHandoff = testingHooks.beforeAcquireHandoff {
+            await beforeAcquireHandoff()
+        }
+        guard token.completeHandoff() else {
+            // A call/Siri interruption or route loss landed after registration
+            // but before ownership handoff. Remove the provisional holder and
+            // fail instead of starting a client engine after the stop event.
+            release(token)
+            throw CancellationError()
+        }
+        return token
+    }
+
+    /// Drops one holder. Deactivates the session (notifying other apps) only
+    /// when the last holder releases. Safe to call more than once, from any
+    /// thread (including `deinit` paths): the work is fire-and-forget onto
+    /// the session queue, so the blocking deactivation IPC never runs on the
+    /// caller.
+    func release(_ token: Token) {
+        guard token.markReleased() else { return }
+        queue.async {
+            self.releaseOnQueue(token)
+        }
+    }
+
+    // MARK: - Queue-confined core
+
+    /// Returns callback tickets for pre-existing live holders whose engines
+    /// must restart because this acquire escalated the category.
+    private func activateOnQueue(_ use: Use, registering token: Token) throws -> [Token.CallbackTicket] {
+        let target: Category = (use == .capture || currentCategory == .playAndRecord) ? .playAndRecord : .playback
+        let categoryChanged = target != currentCategory
+        let previousCategory = currentCategory
+        if categoryChanged {
+            try session.setCategory(target)
+            currentCategory = target
+        }
+        if !sessionActive {
+            do {
+                try session.setActive(true, notifyOthersOnDeactivation: false)
+            } catch {
+                // Activation failed (e.g. a phone call owns the hardware):
+                // with no holder registered, an escalated category recorded
+                // here would stick and pin later playback-only acquires to
+                // .playAndRecord. Existing holders keep the category the
+                // hardware really has.
+                if categoryChanged, holders.isEmpty {
+                    currentCategory = previousCategory
+                }
+                throw error
+            }
+            sessionActive = true
+        }
+
+        let reconfigured = categoryChanged
+            ? holders.values.compactMap { $0.record(.categoryEscalated) }
+            : []
+        holders[ObjectIdentifier(token)] = token
+        return reconfigured
+    }
+
+    private func releaseOnQueue(_ token: Token) {
+        guard holders.removeValue(forKey: ObjectIdentifier(token)) != nil else { return }
+        guard holders.isEmpty else { return }
+        currentCategory = nil
+        guard sessionActive else { return }
+        sessionActive = false
+        do {
+            try session.setActive(false, notifyOthersOnDeactivation: true)
+        } catch {
+            SecureLogger.error("AudioSession: deactivation failed: \(error)", category: .session)
+        }
+    }
+
+    private func onQueue<T: Sendable>(_ body: @escaping @Sendable () -> T) async -> T {
+        await withCheckedContinuation { continuation in
+            queue.async {
+                continuation.resume(returning: body())
+            }
+        }
+    }
+
+    @MainActor
+    private func deliver(_ tickets: [Token.CallbackTicket]) async {
+        guard !tickets.isEmpty else { return }
+        if let beforeCallbackDelivery = testingHooks.beforeCallbackDelivery {
+            await beforeCallbackDelivery()
+        }
+        for ticket in tickets {
+            ticket.token.deliver(ticket)
+        }
+    }
+
+    // MARK: - System events (internal so tests can drive them directly)
+
+    /// A system interruption began: the session is already deactivated by the
+    /// OS, so just mark it inactive and tell every ready holder (on the main
+    /// actor) to stop. A provisional acquiring holder is invalidated instead.
+    /// No auto-resume — the next acquire re-activates.
+    func handleInterruptionBegan() async {
+        let tickets = await onQueue { () -> [Token.CallbackTicket] in
+            self.sessionActive = false
+            return self.holders.values.compactMap { $0.record(.interrupted) }
+        }
+        await deliver(tickets)
+    }
+
+    /// The active route's input/output device disappeared (e.g. BT headset
+    /// off): ready holders' engines are wedged against a dead route — stop
+    /// them; invalidate a holder whose acquire has not returned yet.
+    func handleRouteDeviceUnavailable() async {
+        let tickets = await onQueue {
+            self.holders.values.compactMap { $0.record(.interrupted) }
+        }
+        await deliver(tickets)
+    }
+
+    /// Test hook: suspends until every session operation enqueued before this
+    /// call — including fire-and-forget `release`s — has completed.
+    func drain() async {
+        await onQueue {}
+    }
+
+    private func observeSystemNotifications() {
+        #if os(iOS)
+        let center = NotificationCenter.default
+        observers.append(center.addObserver(
+            forName: AVAudioSession.interruptionNotification,
+            object: AVAudioSession.sharedInstance(),
+            queue: .main
+        ) { [weak self] note in
+            guard let raw = note.userInfo?[AVAudioSessionInterruptionTypeKey] as? UInt,
+                  AVAudioSession.InterruptionType(rawValue: raw) == .began,
+                  let self
+            else { return }
+            SecureLogger.info("AudioSession: interruption began", category: .session)
+            Task { await self.handleInterruptionBegan() }
+        })
+        observers.append(center.addObserver(
+            forName: AVAudioSession.routeChangeNotification,
+            object: AVAudioSession.sharedInstance(),
+            queue: .main
+        ) { [weak self] note in
+            guard let raw = note.userInfo?[AVAudioSessionRouteChangeReasonKey] as? UInt,
+                  AVAudioSession.RouteChangeReason(rawValue: raw) == .oldDeviceUnavailable,
+                  let self
+            else { return }
+            SecureLogger.info("AudioSession: route device became unavailable", category: .session)
+            Task { await self.handleRouteDeviceUnavailable() }
+        })
+        #endif
+    }
+}
+
+// MARK: - Production adapter
+
+#if os(iOS)
+private struct SystemAudioSession: SessionApplying {
+    func setCategory(_ category: AudioSessionCoordinator.Category) throws {
+        let session = AVAudioSession.sharedInstance()
+        switch category {
+        case .playback:
+            try session.setCategory(.playback, mode: .spokenAudio, options: [.mixWithOthers])
+        case .playAndRecord:
+            // allowBluetoothHFP is not available on iOS Simulator
+            #if targetEnvironment(simulator)
+            try session.setCategory(
+                .playAndRecord,
+                mode: .default,
+                options: [.defaultToSpeaker, .allowBluetoothA2DP, .mixWithOthers]
+            )
+            #else
+            try session.setCategory(
+                .playAndRecord,
+                mode: .default,
+                options: [.defaultToSpeaker, .allowBluetoothA2DP, .allowBluetoothHFP, .mixWithOthers]
+            )
+            #endif
+        }
+    }
+
+    func setActive(_ active: Bool, notifyOthersOnDeactivation: Bool) throws {
+        try AVAudioSession.sharedInstance().setActive(
+            active,
+            options: notifyOthersOnDeactivation ? [.notifyOthersOnDeactivation] : []
+        )
+    }
+}
+#else
+/// macOS has no app-level audio session; the coordinator still runs its
+/// bookkeeping so client code is identical across platforms.
+private struct SystemAudioSession: SessionApplying {
+    func setCategory(_ category: AudioSessionCoordinator.Category) throws {}
+    func setActive(_ active: Bool, notifyOthersOnDeactivation: Bool) throws {}
+}
+#endif

bitchat/Features/voice/PTTAudioCodec.swift

@@ -0,0 +1,175 @@
+//
+// PTTAudioCodec.swift
+// bitchat
+//
+// This is free and unencumbered software released into the public domain.
+// For more information, see <https://unlicense.org>
+//
+
+import AVFoundation
+import BitLogger
+import Foundation
+
+/// Streaming PCM -> AAC-LC encoder for live voice. Stateful (the AAC encoder
+/// carries a bit reservoir across frames); one instance per burst.
+/// Not thread-safe — confine to one queue.
+final class PTTFrameEncoder {
+    private let converter: AVAudioConverter
+    private var pendingInput: [AVAudioPCMBuffer] = []
+
+    init?() {
+        guard let pcm = PTTAudioFormat.pcmFormat,
+              let aac = PTTAudioFormat.aacFormat,
+              let converter = AVAudioConverter(from: pcm, to: aac)
+        else { return nil }
+        converter.bitRate = PTTAudioFormat.bitRate
+        self.converter = converter
+    }
+
+    /// Feeds PCM (16 kHz mono float) and returns every complete AAC frame the
+    /// encoder produced. Frames come out ~130 bytes each at 16 kbps.
+    func encode(_ buffer: AVAudioPCMBuffer) -> [Data] {
+        pendingInput.append(buffer)
+        return drainConverter()
+    }
+
+    private func drainConverter() -> [Data] {
+        var frames: [Data] = []
+        while true {
+            let output = AVAudioCompressedBuffer(
+                format: converter.outputFormat,
+                packetCapacity: 8,
+                maximumPacketSize: max(converter.maximumOutputPacketSize, 1)
+            )
+            var error: NSError?
+            let status = converter.convert(to: output, error: &error) { [weak self] _, outStatus in
+                guard let self, let next = self.pendingInput.first else {
+                    outStatus.pointee = .noDataNow
+                    return nil
+                }
+                self.pendingInput.removeFirst()
+                outStatus.pointee = .haveData
+                return next
+            }
+            if status == .error {
+                SecureLogger.error("PTT encode failed: \(error?.localizedDescription ?? "unknown")", category: .session)
+                return frames
+            }
+            frames.append(contentsOf: Self.extractPackets(from: output))
+            // .haveData means the output buffer filled and more may be ready;
+            // anything else means the converter wants more input.
+            if status != .haveData { return frames }
+        }
+    }
+
+    private static func extractPackets(from buffer: AVAudioCompressedBuffer) -> [Data] {
+        guard buffer.packetCount > 0, let descriptions = buffer.packetDescriptions else { return [] }
+        var frames: [Data] = []
+        frames.reserveCapacity(Int(buffer.packetCount))
+        for index in 0..<Int(buffer.packetCount) {
+            let description = descriptions[index]
+            guard description.mDataByteSize > 0 else { continue }
+            let start = buffer.data.advanced(by: Int(description.mStartOffset))
+            frames.append(Data(bytes: start, count: Int(description.mDataByteSize)))
+        }
+        return frames
+    }
+}
+
+/// Streaming AAC-LC -> PCM decoder for live voice. Stateful; one instance per
+/// inbound burst. Not thread-safe — confine to one queue/actor.
+final class PTTFrameDecoder {
+    private let converter: AVAudioConverter
+    private let pcmFormat: AVAudioFormat
+    private let aacFormat: AVAudioFormat
+
+    init?() {
+        guard let pcm = PTTAudioFormat.pcmFormat,
+              let aac = PTTAudioFormat.aacFormat,
+              let converter = AVAudioConverter(from: aac, to: pcm)
+        else { return nil }
+        self.converter = converter
+        self.pcmFormat = pcm
+        self.aacFormat = aac
+    }
+
+    /// Decodes one raw AAC frame to PCM. Returns nil for malformed input or
+    /// while the decoder is still priming (the first frame of a stream).
+    func decode(_ frame: Data) -> AVAudioPCMBuffer? {
+        guard !frame.isEmpty, frame.count <= 8 * 1024 else { return nil }
+
+        let input = AVAudioCompressedBuffer(format: aacFormat, packetCapacity: 1, maximumPacketSize: frame.count)
+        frame.withUnsafeBytes { raw in
+            guard let base = raw.baseAddress else { return }
+            input.data.copyMemory(from: base, byteCount: frame.count)
+        }
+        input.byteLength = UInt32(frame.count)
+        input.packetCount = 1
+        input.packetDescriptions?.pointee = AudioStreamPacketDescription(
+            mStartOffset: 0,
+            mVariableFramesInPacket: 0,
+            mDataByteSize: UInt32(frame.count)
+        )
+
+        guard let output = AVAudioPCMBuffer(
+            pcmFormat: pcmFormat,
+            frameCapacity: PTTAudioFormat.samplesPerFrame * 2
+        ) else { return nil }
+
+        var consumed = false
+        var error: NSError?
+        let status = converter.convert(to: output, error: &error) { _, outStatus in
+            if consumed {
+                outStatus.pointee = .noDataNow
+                return nil
+            }
+            consumed = true
+            outStatus.pointee = .haveData
+            return input
+        }
+        guard status != .error else {
+            SecureLogger.debug("PTT decode failed: \(error?.localizedDescription ?? "unknown")", category: .session)
+            return nil
+        }
+        return output.frameLength > 0 ? output : nil
+    }
+}
+
+/// Sample-rate/channel converter from the microphone's native format to the
+/// 16 kHz mono processing format. Stateful; not thread-safe.
+final class PTTInputResampler {
+    private let converter: AVAudioConverter
+    private let outputFormat: AVAudioFormat
+    private let ratio: Double
+
+    init?(inputFormat: AVAudioFormat) {
+        guard let pcm = PTTAudioFormat.pcmFormat,
+              let converter = AVAudioConverter(from: inputFormat, to: pcm)
+        else { return nil }
+        self.converter = converter
+        self.outputFormat = pcm
+        self.ratio = PTTAudioFormat.sampleRate / inputFormat.sampleRate
+    }
+
+    func resample(_ buffer: AVAudioPCMBuffer) -> AVAudioPCMBuffer? {
+        let capacity = AVAudioFrameCount(Double(buffer.frameLength) * ratio) + 64
+        guard let output = AVAudioPCMBuffer(pcmFormat: outputFormat, frameCapacity: capacity) else { return nil }
+
+        var consumed = false
+        var error: NSError?
+        let status = converter.convert(to: output, error: &error) { _, outStatus in
+            if consumed {
+                outStatus.pointee = .noDataNow
+                return nil
+            }
+            consumed = true
+            outStatus.pointee = .haveData
+            return buffer
+        }
+        guard status != .error else {
+            SecureLogger.debug("PTT resample failed: \(error?.localizedDescription ?? "unknown")", category: .session)
+            return nil
+        }
+        return output.frameLength > 0 ? output : nil
+    }
+}

bitchat/Features/voice/PTTAudioFormat.swift

@@ -0,0 +1,84 @@
+//
+// PTTAudioFormat.swift
+// bitchat
+//
+// This is free and unencumbered software released into the public domain.
+// For more information, see <https://unlicense.org>
+//
+
+import AVFoundation
+import Foundation
+
+/// Shared audio parameters for live push-to-talk: AAC-LC, 16 kHz, mono,
+/// ~16 kbps — deliberately identical to `VoiceRecorder`'s voice-note settings
+/// so a burst's finalized `.m4a` and its live frames sound the same.
+enum PTTAudioFormat {
+    static let sampleRate: Double = 16_000
+    static let channelCount: AVAudioChannelCount = 1
+    static let bitRate = 16_000
+    /// AAC-LC frame size is fixed by the codec: 1024 samples = 64 ms at 16 kHz.
+    static let samplesPerFrame: AVAudioFrameCount = 1024
+    static var frameDuration: TimeInterval { Double(samplesPerFrame) / sampleRate }
+
+    /// Uncompressed processing format (deinterleaved float PCM).
+    static var pcmFormat: AVAudioFormat? {
+        AVAudioFormat(standardFormatWithSampleRate: sampleRate, channels: channelCount)
+    }
+
+    /// Compressed wire format.
+    static var aacFormat: AVAudioFormat? {
+        var description = AudioStreamBasicDescription(
+            mSampleRate: sampleRate,
+            mFormatID: kAudioFormatMPEG4AAC,
+            mFormatFlags: 0,
+            mBytesPerPacket: 0,
+            mFramesPerPacket: samplesPerFrame,
+            mBytesPerFrame: 0,
+            mChannelsPerFrame: channelCount,
+            mBitsPerChannel: 0,
+            mReserved: 0
+        )
+        return AVAudioFormat(streamDescription: &description)
+    }
+
+    /// Voice-note container settings for the finalized `.m4a`, mirroring
+    /// `VoiceRecorder.startRecording()`.
+    static var voiceNoteFileSettings: [String: Any] {
+        [
+            AVFormatIDKey: kAudioFormatMPEG4AAC,
+            AVSampleRateKey: sampleRate,
+            AVNumberOfChannelsKey: Int(channelCount),
+            AVEncoderBitRateKey: bitRate
+        ]
+    }
+}
+
+/// Builds ADTS-framed AAC so a receiver can persist a burst progressively:
+/// unlike `.m4a` (whose moov atom only exists after close), an ADTS `.aac`
+/// stream is playable at any prefix — a partially received burst is still a
+/// replayable voice note.
+enum ADTSFramer {
+    private static let headerSize = 7
+    /// MPEG-4 sampling frequency index for 16 kHz.
+    private static let samplingFrequencyIndex: UInt8 = 8
+    private static let channelConfiguration: UInt8 = 1
+
+    /// Wraps one raw AAC-LC frame in an ADTS header.
+    static func frame(_ aacFrame: Data) -> Data {
+        let frameLength = aacFrame.count + headerSize
+        var data = Data(capacity: frameLength)
+        // Syncword 0xFFF, MPEG-4, layer 00, no CRC.
+        data.append(0xFF)
+        data.append(0xF1)
+        // Profile AAC-LC (audio object type 2 -> bits 01), frequency index,
+        // private bit 0, channel config high bit.
+        data.append((0b01 << 6) | (samplingFrequencyIndex << 2) | ((channelConfiguration >> 2) & 0x1))
+        data.append(((channelConfiguration & 0x3) << 6) | UInt8((frameLength >> 11) & 0x3))
+        data.append(UInt8((frameLength >> 3) & 0xFF))
+        data.append(UInt8((frameLength & 0x7) << 5) | 0x1F)
+        // Buffer fullness 0x7FF (VBR), one AAC frame per ADTS frame.
+        data.append(0xFC)
+        data.append(aacFrame)
+        return data
+    }
+}

bitchat/Features/voice/PTTBurstPlayer.swift

@@ -0,0 +1,509 @@
+//
+// PTTBurstPlayer.swift
+// bitchat
+//
+// This is free and unencumbered software released into the public domain.
+// For more information, see <https://unlicense.org>
+//
+
+@preconcurrency import AVFoundation
+import BitLogger
+import Foundation
+
+/// The engine operations behind live-burst playback, abstracted so the
+/// player's lifecycle (jitter start, category-escalation restart, stop) is
+/// unit-testable without real audio hardware.
+@MainActor
+protocol PTTPlaybackEngine: AnyObject {
+    /// The object `AVAudioEngineConfigurationChange` notifications are posted
+    /// for (nil for mocks — no observer is registered).
+    var configChangeObject: AnyObject? { get }
+    func start() throws
+    func play()
+    func stop()
+    func schedule(
+        _ buffer: AVAudioPCMBuffer,
+        completionType: PTTPlaybackCompletionType,
+        completionHandler: @escaping @Sendable (PTTPlaybackCompletionEvent) -> Void
+    )
+}
+
+/// The lifecycle point requested from `AVAudioPlayerNode` for a scheduled
+/// buffer. `dataConsumed` only means the node no longer needs the bytes; it
+/// may arrive before the render pipeline has made the audio audible.
+enum PTTPlaybackCompletionType: Equatable, Sendable {
+    case dataConsumed
+    case dataPlayedBack
+}
+
+enum PTTPlaybackCompletionEvent: Equatable, Sendable {
+    case dataConsumed
+    case dataPlayedBack
+    /// AVAudioPlayerNode invokes the requested callback when the node is
+    /// stopped too. That is not audible completion and must remain replayable.
+    case playbackStopped
+}
+
+/// One `AVAudioEngine` + `AVAudioPlayerNode` pair. Created fresh per (re)start:
+/// an engine instantiated against an earlier audio-session configuration keeps
+/// rendering to the stale route (same class of failure as the capture side's
+/// fresh-engine-per-press rule).
+@MainActor
+private final class SystemPTTPlaybackEngine: PTTPlaybackEngine {
+    private let engine = AVAudioEngine()
+    private let node = AVAudioPlayerNode()
+
+    init(format: AVAudioFormat) {
+        engine.attach(node)
+        engine.connect(node, to: engine.mainMixerNode, format: format)
+    }
+
+    var configChangeObject: AnyObject? { engine }
+
+    func start() throws {
+        engine.prepare()
+        try engine.start()
+    }
+
+    func play() {
+        node.play()
+    }
+
+    func stop() {
+        node.stop()
+        engine.stop()
+    }
+
+    func schedule(
+        _ buffer: AVAudioPCMBuffer,
+        completionType: PTTPlaybackCompletionType,
+        completionHandler: @escaping @Sendable (PTTPlaybackCompletionEvent) -> Void
+    ) {
+        let callbackType: AVAudioPlayerNodeCompletionCallbackType = switch completionType {
+        case .dataConsumed: .dataConsumed
+        case .dataPlayedBack: .dataPlayedBack
+        }
+        let scheduledEngine = engine
+        node.scheduleBuffer(buffer, completionCallbackType: callbackType) { [weak scheduledEngine] callbackType in
+            // The API invokes this callback when the player is stopped as
+            // well. A configuration change can stop the engine before its
+            // notification reaches MainActor, so do not misclassify that
+            // flushed tail as audible playback.
+            guard scheduledEngine?.isRunning == true else {
+                completionHandler(.playbackStopped)
+                return
+            }
+            switch callbackType {
+            case .dataConsumed:
+                completionHandler(.dataConsumed)
+            case .dataRendered:
+                completionHandler(.dataConsumed)
+            case .dataPlayedBack:
+                completionHandler(.dataPlayedBack)
+            @unknown default:
+                completionHandler(.playbackStopped)
+            }
+        }
+    }
+}
+
+/// Completion callbacks arrive off the main actor, while engine rebuilds are
+/// serialized on it. This small lock-backed latch lets a rebuild atomically
+/// claim only buffers whose completion has not already fired — even when the
+/// callback's hop back to the main actor is still queued.
+private final class PTTPlaybackCompletionState: @unchecked Sendable {
+    private enum State {
+        case scheduled
+        case completed
+        case retired
+    }
+
+    private let lock = NSLock()
+    private var state: State = .scheduled
+
+    /// Returns true exactly once when playback completion wins the race with
+    /// an engine rebuild or stop.
+    func complete() -> Bool {
+        lock.withLock {
+            guard case .scheduled = state else { return false }
+            state = .completed
+            return true
+        }
+    }
+
+    /// Returns true exactly once when a rebuild or stop claims this
+    /// still-pending schedule. Later callbacks from that engine are stale.
+    func retireIfPending() -> Bool {
+        lock.withLock {
+            guard case .scheduled = state else { return false }
+            state = .retired
+            return true
+        }
+    }
+}
+
+/// Plays one inbound live voice burst with a small jitter buffer.
+///
+/// Frames are decoded and scheduled back-to-back on an `AVAudioPlayerNode`;
+/// an underrun (missing/late packets) simply pauses output until the next
+/// buffer arrives, which self-heals timing without explicit silence
+/// insertion. Playback starts once `TransportConfig.pttJitterBufferSeconds`
+/// of audio is queued or `pttJitterDeadlineSeconds` has elapsed.
+///
+/// Talk-over is bidirectional: when push-to-talk capture starts while this
+/// burst plays, the session category escalates underneath the engine — the
+/// player rebuilds a fresh engine against the new configuration and keeps
+/// streaming instead of dying. Real interruptions (phone call, route device
+/// gone) still stop it; the burst keeps assembling to file either way.
+@MainActor
+final class PTTBurstPlayer {
+    /// Restart-on-reconfigure ceiling: a burst is at most ~2 minutes, so a
+    /// handful of category/route changes is plenty — beyond it something is
+    /// thrashing and stopping cleanly beats an engine-rebuild loop.
+    private static let maxEngineRestarts = 8
+
+    private let makeEngine: @MainActor () -> PTTPlaybackEngine
+    private var engine: PTTPlaybackEngine
+    private let decoder: PTTFrameDecoder
+    private let coordinator: AudioSessionCoordinator
+    /// Injectable so tests don't fight over the app-wide exclusive-playback
+    /// slot (a parallel test's `play()` would stop this player mid-test).
+    private let exclusivity: VoiceNotePlaybackCoordinator
+
+    private var queuedBuffers: [AVAudioPCMBuffer] = []
+    private var queuedDuration: TimeInterval = 0
+    private struct ScheduledBuffer {
+        let id: UInt64
+        let buffer: AVAudioPCMBuffer
+        let completionState: PTTPlaybackCompletionState
+    }
+    /// Buffers handed to the current engine whose completion has not yet
+    /// been processed on the main actor. Keeping the buffers themselves lets
+    /// a category-escalation rebuild replay the unfinished tail in order.
+    private var scheduledBuffers: [ScheduledBuffer] = []
+    private var nextScheduledBufferID: UInt64 = 0
+    /// Bumped on every engine rebuild or stop so completion tasks from a
+    /// torn-down engine cannot mutate the current generation's pending list.
+    private var engineGeneration = 0
+    private var engineRestarts = 0
+    private var engineStarted = false
+    private var finished = false
+    /// Latched off (internal read so tests can await the async failure path).
+    private(set) var stopped = false
+    /// A session acquire is in flight (it suspends off-main for the blocking
+    /// session IPC); gates `startIfReady` against double acquisition.
+    private var acquiringSession = false
+    private var deadlineTask: Task<Void, Never>?
+    private var sessionToken: AudioSessionCoordinator.Token?
+    /// Reserved before the session acquire suspends. Activation succeeds only
+    /// if no newer playback request claimed the floor in the meantime.
+    private var playbackReservation: VoiceNotePlaybackCoordinator.Reservation?
+    private var configChangeObserver: NSObjectProtocol?
+
+    private(set) var isPlaying = false
+
+    /// Fires exactly once when the player stops for good (drain-out, cancel,
+    /// interruption, failure). `ChatLiveVoiceCoordinator` uses it to unpark
+    /// the draining player it keeps alive after the assembly — the player's
+    /// only long-lived owner — is discarded on burst END.
+    var onStopped: (() -> Void)?
+
+    init?(
+        coordinator: AudioSessionCoordinator? = nil,
+        exclusivity: VoiceNotePlaybackCoordinator? = nil,
+        makeEngine: (@MainActor () -> PTTPlaybackEngine)? = nil
+    ) {
+        guard let format = PTTAudioFormat.pcmFormat, let decoder = PTTFrameDecoder() else { return nil }
+        self.decoder = decoder
+        self.coordinator = coordinator ?? .shared
+        self.exclusivity = exclusivity ?? .shared
+        let factory = makeEngine ?? { SystemPTTPlaybackEngine(format: format) }
+        self.makeEngine = factory
+        self.engine = factory()
+
+        deadlineTask = Task { [weak self] in
+            try? await Task.sleep(nanoseconds: UInt64(TransportConfig.pttJitterDeadlineSeconds * 1_000_000_000))
+            self?.startIfReady(force: true)
+        }
+    }
+
+    deinit {
+        // Backstop for an owner dropping the player before it stopped: the
+        // session coordinator retains registered tokens strongly, so a token
+        // leaked here would keep the session active (and pin any escalated
+        // category) for the app's lifetime. `release` is fire-and-forget
+        // onto the coordinator's queue, so it is deinit-safe.
+        if let token = sessionToken {
+            coordinator.release(token)
+        }
+        if let observer = configChangeObserver {
+            NotificationCenter.default.removeObserver(observer)
+        }
+        deadlineTask?.cancel()
+    }
+
+    /// Decodes and queues frames (in burst order). Starts playback when the
+    /// jitter buffer fills.
+    func enqueue(_ frames: [Data]) {
+        guard !stopped else { return }
+        for frame in frames {
+            guard let pcm = decoder.decode(frame) else { continue }
+            if engineStarted {
+                schedule(pcm)
+            } else {
+                queuedBuffers.append(pcm)
+                queuedDuration += Double(pcm.frameLength) / PTTAudioFormat.sampleRate
+            }
+        }
+        startIfReady(force: false)
+    }
+
+    /// The burst ended: stop once everything scheduled has played out.
+    func finishAfterDrain() {
+        finished = true
+        // The complete burst is queued — no jitter left to wait for. This
+        // also matters when END lands while the async session acquire is
+        // still in flight: the queued audio must play out, not be treated
+        // as already drained.
+        startIfReady(force: true)
+        stopIfDrained()
+    }
+
+    /// Immediate stop (cancel, another playback taking over, interruption,
+    /// teardown).
+    func stop() {
+        guard !stopped else { return }
+        stopped = true
+        deadlineTask?.cancel()
+        removeConfigObserver()
+        queuedBuffers = []
+        retireScheduledBuffers()
+        if engineStarted {
+            engine.stop()
+        }
+        isPlaying = false
+        releaseSessionToken()
+        exclusivity.deactivate(self)
+        onStopped?()
+    }
+
+    private func startIfReady(force: Bool) {
+        guard !engineStarted, !acquiringSession, !stopped, !queuedBuffers.isEmpty else { return }
+        guard force || queuedDuration >= TransportConfig.pttJitterBufferSeconds else { return }
+
+        // Acquiring the session suspends for its blocking IPC (off the main
+        // actor); frames arriving meanwhile keep queueing and are flushed
+        // onto the engine once it starts.
+        acquiringSession = true
+        playbackReservation = exclusivity.reserve(self)
+        Task { [weak self] in
+            await self?.acquireSessionAndStart()
+        }
+    }
+
+    private func acquireSessionAndStart() async {
+        let token: AudioSessionCoordinator.Token
+        do {
+            token = try await coordinator.acquire(
+                .playback,
+                onInterrupted: { [weak self] in self?.stop() },
+                onCategoryEscalated: { [weak self] in self?.restartEngine() }
+            )
+        } catch {
+            acquiringSession = false
+            SecureLogger.error("PTT playback session activation failed: \(error)", category: .session)
+            // Playing unregistered would leave the engine exposed: another
+            // holder's last release deactivates the session mid-play, and no
+            // interruption/escalation fan-out ever reaches us. Bail like the
+            // engine-start failure below; the burst still assembles to file.
+            // (stop() also fires onStopped so a parked draining player is
+            // unparked instead of leaking.)
+            stop()
+            return
+        }
+        acquiringSession = false
+        // stop() (cancel, exclusivity, teardown) may have landed while the
+        // session was activating: hand the token straight back.
+        guard !stopped else {
+            coordinator.release(token)
+            return
+        }
+        sessionToken = token
+        guard let playbackReservation,
+              exclusivity.isCurrent(playbackReservation, for: self)
+        else {
+            // The request was superseded while audio-session activation was
+            // suspended. Do not even start the retired engine.
+            stop()
+            return
+        }
+
+        // Observe reconfiguration before starting so nothing lands between.
+        registerConfigObserver()
+        do {
+            try engine.start()
+        } catch {
+            // A capture racing this start can reconfigure the session while
+            // the engine spins up (its escalation fan-out no-ops on a player
+            // that never started): rebuild once against the settled
+            // configuration — counted against the restart cap — before
+            // giving up.
+            SecureLogger.warning("PTT playback engine failed to start (\(error)) — rebuilding once", category: .session)
+            removeConfigObserver()
+            engineRestarts += 1
+            engine = makeEngine()
+            registerConfigObserver()
+            do {
+                try engine.start()
+            } catch {
+                SecureLogger.error("PTT playback engine failed to start: \(error)", category: .session)
+                // stop() removes the observer, hands the token back, and
+                // fires onStopped for any parked draining owner.
+                stop()
+                return
+            }
+        }
+        engineStarted = true
+        guard exclusivity.activate(self, reservation: playbackReservation)
+        else {
+            // A newer user-initiated playback reserved the floor while this
+            // older PTT request was suspended in audio-session activation.
+            // Never let the late completion steal playback back.
+            stop()
+            return
+        }
+        isPlaying = true
+        engine.play()
+
+        let buffered = queuedBuffers
+        queuedBuffers = []
+        queuedDuration = 0
+        for buffer in buffered {
+            schedule(buffer)
+        }
+    }
+
+    /// The audio session was reconfigured underneath the running engine
+    /// (category escalation for talk-over, or an engine configuration
+    /// change): rebuild a fresh engine against the new configuration and
+    /// keep streaming. Buffers already completed stay completed; the
+    /// unfinished scheduled tail is replayed in order on the fresh engine,
+    /// and frames still arriving continue scheduling after it.
+    private func restartEngine() {
+        guard engineStarted, !stopped else { return }
+        engineRestarts += 1
+        guard engineRestarts <= Self.maxEngineRestarts else {
+            SecureLogger.warning("PTT playback: engine reconfigured \(engineRestarts) times in one burst — stopping", category: .session)
+            stop()
+            return
+        }
+
+        removeConfigObserver()
+        // Claim the unfinished tail before stopping the old engine. Stopping
+        // a player node may itself invoke its completion handlers; retiring
+        // the claimed entries first makes those callbacks unambiguously stale.
+        // A completion that fired just before this rebuild wins the latch and
+        // is excluded even if its MainActor task has not run yet.
+        let buffersToReplay = scheduledBuffers.compactMap { scheduled in
+            scheduled.completionState.retireIfPending() ? scheduled.buffer : nil
+        }
+        scheduledBuffers = []
+        engineGeneration += 1
+        engine.stop()
+        engine = makeEngine()
+        registerConfigObserver()
+        do {
+            try engine.start()
+        } catch {
+            SecureLogger.error("PTT playback engine failed to restart after session reconfigure: \(error)", category: .session)
+            stop()
+            return
+        }
+        engine.play()
+        for buffer in buffersToReplay {
+            schedule(buffer)
+        }
+        SecureLogger.info("PTT playback: engine restarted after session reconfigure", category: .session)
+        // If every old buffer completed before the rebuild, a finished burst
+        // can stop now. Otherwise the replayed tail keeps it alive until its
+        // new-generation completions arrive.
+        stopIfDrained()
+    }
+
+    private func registerConfigObserver() {
+        guard let object = engine.configChangeObject else { return }
+        configChangeObserver = NotificationCenter.default.addObserver(
+            forName: .AVAudioEngineConfigurationChange,
+            object: object,
+            queue: .main
+        ) { [weak self] _ in
+            Task { @MainActor [weak self] in
+                self?.restartEngine()
+            }
+        }
+    }
+
+    private func removeConfigObserver() {
+        if let observer = configChangeObserver {
+            NotificationCenter.default.removeObserver(observer)
+            configChangeObserver = nil
+        }
+    }
+
+    private func schedule(_ buffer: AVAudioPCMBuffer) {
+        let id = nextScheduledBufferID
+        nextScheduledBufferID &+= 1
+        let completionState = PTTPlaybackCompletionState()
+        scheduledBuffers.append(ScheduledBuffer(
+            id: id,
+            buffer: buffer,
+            completionState: completionState
+        ))
+        let generation = engineGeneration
+        engine.schedule(buffer, completionType: .dataPlayedBack) { [weak self, completionState] event in
+            guard event == .dataPlayedBack else { return }
+            // Mark completion before hopping to MainActor. A rebuild can then
+            // distinguish already-completed audio from an unfinished tail
+            // even when this task has not run yet.
+            guard completionState.complete() else { return }
+            Task { @MainActor [weak self] in
+                guard let self, self.engineGeneration == generation else { return }
+                self.scheduledBuffers.removeAll { $0.id == id }
+                self.stopIfDrained()
+            }
+        }
+    }
+
+    private func retireScheduledBuffers() {
+        engineGeneration += 1
+        for scheduled in scheduledBuffers {
+            _ = scheduled.completionState.retireIfPending()
+        }
+        scheduledBuffers = []
+    }
+
+    private func stopIfDrained() {
+        guard finished, scheduledBuffers.isEmpty else { return }
+        // Started: everything scheduled has played out. Never started with
+        // nothing queued or in flight (e.g. no decodable frames): nothing
+        // will ever play. Otherwise the engine start is still pending (the
+        // async session acquire) and the queued audio must play out first.
+        guard engineStarted || (!acquiringSession && queuedBuffers.isEmpty) else { return }
+        stop()
+    }
+
+    private func releaseSessionToken() {
+        sessionToken.map(coordinator.release)
+        sessionToken = nil
+    }
+}
+
+extension PTTBurstPlayer: ExclusivePlayback {
+    /// A live stream can't meaningfully pause; yielding the floor stops it.
+    /// The burst keeps assembling to file, so nothing is lost.
+    nonisolated func pauseForExclusivity() {
+        Task { @MainActor [weak self] in
+            self?.stop()
+        }
+    }
+}

bitchat/Features/voice/PTTCaptureEngine.swift

@@ -0,0 +1,326 @@
+//
+// PTTCaptureEngine.swift
+// bitchat
+//
+// This is free and unencumbered software released into the public domain.
+// For more information, see <https://unlicense.org>
+//
+
+import AVFoundation
+import BitLogger
+import Foundation
+
+/// Owns one capture token and returns it even when the capture engine's owner
+/// disappears without reaching its normal stop/cancel path. The coordinator
+/// retains registered tokens strongly, so relying on `Token.deinit` cannot
+/// reclaim an abandoned hold.
+final class PTTCaptureSessionLease: @unchecked Sendable {
+    private let coordinator: AudioSessionCoordinator
+    private let lock = NSLock()
+    private var token: AudioSessionCoordinator.Token?
+
+    init(coordinator: AudioSessionCoordinator) {
+        self.coordinator = coordinator
+    }
+
+    func install(_ token: AudioSessionCoordinator.Token) {
+        let previous = lock.withLock {
+            let previous = self.token
+            self.token = token
+            return previous
+        }
+        previous.map(coordinator.release)
+    }
+
+    func release() {
+        let token = lock.withLock {
+            let token = self.token
+            self.token = nil
+            return token
+        }
+        token.map(coordinator.release)
+    }
+
+    deinit {
+        release()
+    }
+}
+
+/// Monotonic capture identity shared by main-actor lifecycle code and queued
+/// engine callbacks. Removing a notification observer does not cancel a block
+/// already enqueued on the main queue, so every callback must also prove it
+/// still belongs to the current hold before mutating capture state.
+final class PTTCaptureGeneration: @unchecked Sendable {
+    private let lock = NSLock()
+    private var value: UInt = 0
+
+    func begin() -> UInt {
+        lock.withLock {
+            value &+= 1
+            return value
+        }
+    }
+
+    func invalidate() {
+        lock.withLock { value &+= 1 }
+    }
+
+    func invalidate(ifCurrent generation: UInt) -> Bool {
+        lock.withLock {
+            guard value == generation else { return false }
+            value &+= 1
+            return true
+        }
+    }
+
+    func isCurrent(_ generation: UInt) -> Bool {
+        lock.withLock { value == generation }
+    }
+}
+
+/// Captures microphone audio for a live push-to-talk burst, producing both:
+/// - live AAC frames via `onFrames` (called on the capture queue), and
+/// - a finalized `.m4a` voice note on `stop()` — the same artifact
+///   `VoiceRecorder` produces, so the existing voice-note send pipeline
+///   handles delivery to receivers that missed the live stream.
+/// `@unchecked Sendable`: every mutable property is confined to one executor —
+/// the capture `queue` (resampler/encoder/file/counters) or the main actor
+/// (`engine`, `engineStarted`, `sessionLease`, `configChangeObserver`) — so
+/// weak references may cross the `@Sendable` tap/notification closures, which
+/// immediately hop back to the owning executor.
+final class PTTCaptureEngine: @unchecked Sendable {
+    /// Hard cap matching `VoiceRecorder.maxRecordingDuration`: past it the
+    /// engine keeps running (the UI owns the gesture) but stops encoding.
+    private static let maxCaptureDuration: TimeInterval = 120
+
+    /// Recreated on every `start()`: an engine whose input unit was
+    /// instantiated against an earlier (playback-only or inactive) audio
+    /// session keeps reporting a dead 0 Hz / 2 ch input format and fails to
+    /// enable the mic (AURemoteIO -10851, observed on iPhone field tests).
+    private var engine = AVAudioEngine()
+    private let queue = DispatchQueue(label: "chat.bitchat.ptt.capture", qos: .userInitiated)
+    private let coordinator: AudioSessionCoordinator
+    private let sessionLease: PTTCaptureSessionLease
+    private let captureGeneration = PTTCaptureGeneration()
+
+    // Capture-queue-confined state.
+    private var resampler: PTTInputResampler?
+    private var encoder: PTTFrameEncoder?
+    private var file: AVAudioFile?
+    private var fileURL: URL?
+    private var encodedFrameCount = 0
+    private var running = false
+    private var captureStart = Date()
+    /// Whether `engine.start()` succeeded for the current capture
+    /// (see `stopEngineIfStarted`).
+    @MainActor private var engineStarted = false
+    @MainActor private var configChangeObserver: NSObjectProtocol?
+    /// Called on the capture queue with each batch of encoded AAC frames.
+    var onFrames: (([Data]) -> Void)?
+
+    enum CaptureError: Error {
+        case inputUnavailable
+        case audioSetupFailed
+    }
+
+    init(coordinator: AudioSessionCoordinator = .shared) {
+        self.coordinator = coordinator
+        self.sessionLease = PTTCaptureSessionLease(coordinator: coordinator)
+    }
+
+    deinit {
+        sessionLease.release()
+    }
+
+    /// Async because acquiring the session hops its blocking IPC off the main
+    /// actor (a PTT press used to stall main >1 s in `setActive`); the engine
+    /// itself still starts back on main once the session is configured.
+    @MainActor
+    func start(outputURL: URL) async throws {
+        let generation = captureGeneration.begin()
+        let token = try await coordinator.acquire(.capture) { [weak self] in
+            self?.handleInterruption(for: generation)
+        }
+        // The hold ended (stop/cancel) while the session was activating:
+        // starting the engine now would leave a hot mic after release.
+        guard captureGeneration.isCurrent(generation) else {
+            coordinator.release(token)
+            throw CancellationError()
+        }
+        sessionLease.install(token)
+        do {
+            try beginCapture(outputURL: outputURL, generation: generation)
+        } catch {
+            releaseSessionToken()
+            throw error
+        }
+    }
+
+    @MainActor
+    private func beginCapture(outputURL: URL, generation: UInt) throws {
+        // Fresh engine per capture so its input unit binds to the session
+        // that is active *now* (see `engine` doc comment).
+        engine = AVAudioEngine()
+        let inputFormat = engine.inputNode.outputFormat(forBus: 0)
+        guard inputFormat.sampleRate > 0, inputFormat.channelCount > 0 else {
+            SecureLogger.error("PTT: capture input unavailable (input reports \(Int(inputFormat.sampleRate)) Hz, \(inputFormat.channelCount) ch)", category: .session)
+            throw CaptureError.inputUnavailable
+        }
+        guard let resampler = PTTInputResampler(inputFormat: inputFormat),
+              let encoder = PTTFrameEncoder(),
+              let pcmFormat = PTTAudioFormat.pcmFormat
+        else { throw CaptureError.audioSetupFailed }
+
+        let file = try AVAudioFile(
+            forWriting: outputURL,
+            settings: PTTAudioFormat.voiceNoteFileSettings,
+            commonFormat: pcmFormat.commonFormat,
+            interleaved: pcmFormat.isInterleaved
+        )
+
+        queue.sync {
+            self.resampler = resampler
+            self.encoder = encoder
+            self.file = file
+            self.fileURL = outputURL
+            self.encodedFrameCount = 0
+            self.captureStart = Date()
+            self.running = true
+        }
+
+        engine.inputNode.installTap(onBus: 0, bufferSize: 4096, format: inputFormat) { [weak self] buffer, _ in
+            self?.queue.async { self?.process(buffer, generation: generation) }
+        }
+        // Route/category changes reconfigure the engine underneath the tap;
+        // stop and finalize cleanly — the .m4a captured so far still sends.
+        // Registered before start() so no reconfigure lands unobserved
+        // (handleInterruption also validates this capture generation).
+        configChangeObserver = NotificationCenter.default.addObserver(
+            forName: .AVAudioEngineConfigurationChange,
+            object: engine,
+            queue: .main
+        ) { [weak self] _ in
+            Task { @MainActor [weak self] in
+                self?.handleInterruption(for: generation)
+            }
+        }
+        engine.prepare()
+        do {
+            try engine.start()
+        } catch {
+            SecureLogger.error("PTT: capture engine failed to start (input: \(Int(inputFormat.sampleRate)) Hz, \(inputFormat.channelCount) ch): \(error)", category: .session)
+            if let observer = configChangeObserver {
+                NotificationCenter.default.removeObserver(observer)
+                configChangeObserver = nil
+            }
+            engine.inputNode.removeTap(onBus: 0)
+            queue.sync { self.teardown(deleteFile: true) }
+            throw error
+        }
+        engineStarted = true
+        SecureLogger.info("PTT: capture engine running (input: \(Int(inputFormat.sampleRate)) Hz, \(inputFormat.channelCount) ch)", category: .session)
+    }
+
+    /// Stops capture and finalizes the `.m4a`. Returns the file URL and the
+    /// number of encoded AAC frames (each `PTTAudioFormat.frameDuration` long).
+    @MainActor
+    func stop() -> (url: URL?, encodedFrames: Int) {
+        captureGeneration.invalidate()
+        stopEngineIfStarted()
+        let result: (URL?, Int) = queue.sync {
+            let url = fileURL
+            let frames = encodedFrameCount
+            teardown(deleteFile: false)
+            return (url, frames)
+        }
+        releaseSessionToken()
+        return result
+    }
+
+    @MainActor
+    func cancel() {
+        captureGeneration.invalidate()
+        stopEngineIfStarted()
+        queue.sync { teardown(deleteFile: true) }
+        releaseSessionToken()
+    }
+
+    /// Audio session interrupted (call, Siri) or the engine was reconfigured
+    /// mid-capture: behave like `stop()` — finalize the `.m4a` container but
+    /// keep `fileURL`/`encodedFrameCount` so the caller's pending `stop()`
+    /// still returns the note for delivery.
+    @MainActor
+    private func handleInterruption(for generation: UInt) {
+        // Also invalidate a start whose acquire has registered its token but
+        // has not returned to this actor yet. Without this bump the callback
+        // is lost while `engineStarted == false`, and the resumed start can
+        // open the mic after the stop signal.
+        guard captureGeneration.invalidate(ifCurrent: generation) else { return }
+        guard engineStarted else {
+            releaseSessionToken()
+            return
+        }
+        stopEngineIfStarted()
+        queue.sync {
+            running = false
+            // Releasing the AVAudioFile finalizes the .m4a container.
+            file = nil
+            encoder = nil
+            resampler = nil
+        }
+        releaseSessionToken()
+        SecureLogger.info("PTT: capture interrupted — burst finalized early", category: .session)
+    }
+
+    /// Touching `inputNode` on an engine that never started instantiates its
+    /// input unit against whatever session is active and spams AURemoteIO
+    /// errors — a canceled-before-start hold must not touch the engine.
+    @MainActor
+    private func stopEngineIfStarted() {
+        if let observer = configChangeObserver {
+            NotificationCenter.default.removeObserver(observer)
+            configChangeObserver = nil
+        }
+        guard engineStarted else { return }
+        engineStarted = false
+        engine.inputNode.removeTap(onBus: 0)
+        engine.stop()
+    }
+
+    @MainActor
+    private func releaseSessionToken() {
+        sessionLease.release()
+    }
+
+    // MARK: - Capture queue
+
+    private func process(_ buffer: AVAudioPCMBuffer, generation: UInt) {
+        guard captureGeneration.isCurrent(generation),
+              running,
+              Date().timeIntervalSince(captureStart) < Self.maxCaptureDuration,
+              let resampled = resampler?.resample(buffer)
+        else { return }
+
+        do {
+            try file?.write(from: resampled)
+        } catch {
+            SecureLogger.error("PTT capture file write failed: \(error)", category: .session)
+        }
+
+        guard let frames = encoder?.encode(resampled), !frames.isEmpty else { return }
+        encodedFrameCount += frames.count
+        onFrames?(frames)
+    }
+
+    private func teardown(deleteFile: Bool) {
+        running = false
+        // Releasing the AVAudioFile finalizes the .m4a container.
+        file = nil
+        encoder = nil
+        resampler = nil
+        if deleteFile, let url = fileURL {
+            try? FileManager.default.removeItem(at: url)
+        }
+        fileURL = nil
+    }
+}

bitchat/Features/voice/PTTSettings.swift

@@ -0,0 +1,39 @@
+//
+// PTTSettings.swift
+// bitchat
+//
+// This is free and unencumbered software released into the public domain.
+// For more information, see <https://unlicense.org>
+//
+
+import Foundation
+#if os(iOS)
+import UIKit
+#elseif os(macOS)
+import AppKit
+#endif
+
+/// User preference for live push-to-talk voice. One switch controls both
+/// directions: streaming your holds live, and auto-playing inbound bursts.
+/// Off means voice messages behave exactly like classic voice notes.
+enum PTTSettings {
+    private static let liveVoiceEnabledKey = "ptt.liveVoiceEnabled"
+
+    static var liveVoiceEnabled: Bool {
+        get { UserDefaults.standard.object(forKey: liveVoiceEnabledKey) as? Bool ?? true }
+        set { UserDefaults.standard.set(newValue, forKey: liveVoiceEnabledKey) }
+    }
+
+    /// Autoplay is foreground-only: audio must never start from the
+    /// background.
+    @MainActor
+    static var isAppActive: Bool {
+        #if os(iOS)
+        return UIApplication.shared.applicationState == .active
+        #elseif os(macOS)
+        return NSApplication.shared.isActive
+        #else
+        return true
+        #endif
+    }
+}

bitchat/Features/voice/VoiceCaptureSession.swift

@@ -0,0 +1,250 @@
+//
+// VoiceCaptureSession.swift
+// bitchat
+//
+// This is free and unencumbered software released into the public domain.
+// For more information, see <https://unlicense.org>
+//
+
+import BitFoundation
+import BitLogger
+import Foundation
+
+/// Capture backend behind the composer's hold-to-record gesture.
+/// `VoiceRecordingViewModel` drives one session per press; the concrete type
+/// decides *how* audio leaves the device: `VoiceNoteCaptureSession` records a
+/// note delivered on release (today's behavior), `PTTLiveVoiceSession`
+/// additionally streams frames live while the button is held.
+@MainActor
+protocol VoiceCaptureSession: AnyObject {
+    /// Whether audio is leaving the device in real time while recording —
+    /// drives the composer's LIVE treatment.
+    var isLive: Bool { get }
+    func requestPermission() async -> Bool
+    func start() async throws
+    /// Stops capture and returns the finalized voice-note file, or nil when
+    /// nothing valid was captured.
+    func finish() async -> URL?
+    func cancel() async
+    /// Stops capture and suppresses every later send before returning.
+    func panicCancelSynchronously()
+}
+
+/// The classic record-then-send backend, wrapping the shared `VoiceRecorder`.
+@MainActor
+final class VoiceNoteCaptureSession: VoiceCaptureSession {
+    private let recorder: VoiceRecorder
+    private let owner = VoiceRecorder.RecordingOwner()
+
+    var isLive: Bool { false }
+
+    init(recorder: VoiceRecorder = .shared) {
+        self.recorder = recorder
+    }
+
+    func requestPermission() async -> Bool {
+        await recorder.requestPermission()
+    }
+
+    func start() async throws {
+        try await recorder.startRecording(owner: owner)
+    }
+
+    func finish() async -> URL? {
+        await recorder.stopRecording(owner: owner)
+    }
+
+    func cancel() async {
+        await recorder.cancelRecording(owner: owner)
+    }
+
+    func panicCancelSynchronously() {
+        recorder.panicCancelSynchronously(owner: owner)
+    }
+}
+
+/// Testable surface of the live capture engine. Production uses
+/// `PTTCaptureEngine`; tests can supply captured-frame counts without opening
+/// real audio hardware.
+@MainActor
+protocol PTTCapturing: AnyObject {
+    var onFrames: (([Data]) -> Void)? { get set }
+    func start(outputURL: URL) async throws
+    func stop() -> (url: URL?, encodedFrames: Int)
+    func cancel()
+}
+
+extension PTTCaptureEngine: PTTCapturing {}
+
+/// Live push-to-talk backend: streams `VoiceBurstPacket`s to one peer while
+/// recording, then finalizes the same audio as a standard voice note whose
+/// file name carries the burst ID (`voice_<burstID>.m4a`) so receivers that
+/// heard the live stream absorb the note silently instead of seeing a
+/// duplicate.
+@MainActor
+final class PTTLiveVoiceSession: VoiceCaptureSession {
+    let burstID: Data
+
+    private let sendPacket: (Data) -> Void
+    private let capture: any PTTCapturing
+    private let now: () -> Date
+    /// Capture-queue-confined stream state: packetizes frames and lazily
+    /// emits START so packet order is guaranteed by queue serialization.
+    private final class StreamState {
+        var packetizer: VoiceBurstPacketizer
+        var sentStart = false
+        init(burstID: Data) {
+            packetizer = VoiceBurstPacketizer(burstID: burstID)
+        }
+    }
+    private let stream: StreamState
+    private var startDate: Date?
+    private var completed = false
+
+    var isLive: Bool { true }
+
+    /// - Parameter sendPacket: delivers one encoded `VoiceBurstPacket` to the
+    ///   target peer; must be safe to call from any queue (BLEService hops to
+    ///   its own message queue internally).
+    init(
+        sendPacket: @escaping (Data) -> Void,
+        capture: (any PTTCapturing)? = nil,
+        now: @escaping () -> Date = Date.init,
+        burstID: Data? = nil
+    ) {
+        self.burstID = burstID ?? VoiceBurstPacket.makeBurstID()
+        self.sendPacket = sendPacket
+        self.capture = capture ?? PTTCaptureEngine()
+        self.now = now
+        self.stream = StreamState(burstID: self.burstID)
+    }
+
+    func requestPermission() async -> Bool {
+        await VoiceRecorder.shared.requestPermission()
+    }
+
+    func start() async throws {
+        let outputURL = try Self.makeOutputURL(burstID: burstID)
+        let sendPacket = sendPacket
+        let stream = stream
+        capture.onFrames = { frames in
+            if !stream.sentStart {
+                stream.sentStart = true
+                if let start = VoiceBurstPacket(
+                    burstID: stream.packetizer.burstID,
+                    seq: 0,
+                    kind: .start(codec: .aacLC16kMono)
+                ) {
+                    sendPacket(start.encode())
+                }
+            }
+            for frame in frames {
+                for packet in stream.packetizer.add(frame) {
+                    sendPacket(packet)
+                }
+            }
+            // Flush per callback batch: at ~130-byte frames the budget fits
+            // one frame per packet anyway, and holding residue would add
+            // ~100 ms of avoidable latency.
+            for packet in stream.packetizer.flush() {
+                sendPacket(packet)
+            }
+        }
+        do {
+            try await capture.start(outputURL: outputURL)
+        } catch is CancellationError {
+            // The hold was released/canceled while the session acquire was
+            // in flight: the engine never started and the capture already
+            // handed its token back — nothing to retry. A coordinator-side
+            // interruption during handoff also cancels acquire, but that is
+            // not a successful start and must propagate to the view model.
+            guard completed else { throw CancellationError() }
+            return
+        } catch {
+            // The HAL can briefly report a dead input right after the audio
+            // session (re)activates while the route settles; one retry after
+            // a short pause covers it (observed on iPhone field tests).
+            SecureLogger.warning("PTT: capture start failed (\(error)) — retrying once after route settle", category: .session)
+            try? await Task.sleep(nanoseconds: 150_000_000)
+            // The hold may have been released/canceled during the retry pause.
+            // Starting the mic now would leave it live and streaming after the
+            // user let go, so bail instead of opening a hot mic.
+            guard !completed else {
+                capture.cancel()
+                return
+            }
+            try await capture.start(outputURL: outputURL)
+        }
+        startDate = now()
+        SecureLogger.info("PTT: live burst \(burstID.hexEncodedString()) capture started", category: .session)
+    }
+
+    func finish() async -> URL? {
+        guard !completed else { return nil }
+        completed = true
+
+        let elapsed = startDate.map { now().timeIntervalSince($0) } ?? 0
+        let (url, encodedFrames) = capture.stop()
+        // stop() drained the capture queue, so touching `stream` is safe now.
+
+        let capturedDuration = Double(encodedFrames) * PTTAudioFormat.frameDuration
+
+        guard elapsed >= VoiceRecorder.minRecordingDuration,
+              capturedDuration >= VoiceRecorder.minRecordingDuration,
+              let url
+        else {
+            sendControlPacket(.canceled)
+            if let url {
+                try? FileManager.default.removeItem(at: url)
+            }
+            return nil
+        }
+
+        for packet in stream.packetizer.flush() {
+            sendPacket(packet)
+        }
+        let durationMs = UInt32((capturedDuration * 1000).rounded())
+        sendControlPacket(.end(totalDataPackets: stream.packetizer.dataPacketCount, durationMs: durationMs))
+        SecureLogger.info("PTT: live burst \(burstID.hexEncodedString()) finished — \(stream.packetizer.dataPacketCount) data packets, \(encodedFrames) frames, \(durationMs) ms", category: .session)
+        return url
+    }
+
+    func cancel() async {
+        let alreadyCompleted = completed
+        completed = true
+        // Always tear down the capture, even if a quick-release already marked
+        // us completed: the engine can start late (during start()'s retry
+        // pause), and only capture.cancel() stops the mic and deactivates the
+        // session. It is idempotent, so a redundant call is harmless.
+        capture.cancel()
+        if !alreadyCompleted {
+            sendControlPacket(.canceled)
+        }
+    }
+
+    func panicCancelSynchronously() {
+        // Do not emit a canceled packet: it would itself be pre-panic
+        // conversation data racing the emergency transport reset.
+        completed = true
+        capture.cancel()
+    }
+
+    private func sendControlPacket(_ kind: VoiceBurstPacket.Kind) {
+        guard let packet = VoiceBurstPacket(burstID: burstID, seq: stream.packetizer.nextSeq, kind: kind) else { return }
+        sendPacket(packet.encode())
+    }
+
+    private static func makeOutputURL(burstID: Data) throws -> URL {
+        let base = try FileManager.default.url(
+            for: .applicationSupportDirectory,
+            in: .userDomainMask,
+            appropriateFor: nil,
+            create: true
+        )
+        let directory = base
+            .appendingPathComponent("files", isDirectory: true)
+            .appendingPathComponent("voicenotes/outgoing", isDirectory: true)
+        try FileManager.default.createDirectory(at: directory, withIntermediateDirectories: true, attributes: BLEIncomingFileStore.mediaProtectionAttributes)
+        return directory.appendingPathComponent("voice_\(burstID.hexEncodedString()).m4a")
+    }
+}

bitchat/Features/voice/VoiceNotePlaybackController.swift

@@ -9,6 +9,9 @@ final class VoiceNotePlaybackController: NSObject, ObservableObject, AVAudioPlay
     @Published private(set) var duration: TimeInterval = 0
     @Published private(set) var progress: Double = 0
 
+    /// Internal lifecycle visibility for deterministic acquisition tests.
+    var isPlaybackStartPending: Bool { sessionAcquireInFlight }
+
     /// rounded so 4.9s shows "00:05"
     var roundedDuration: Int {
         guard duration.isFinite else { return 0 }
@@ -24,9 +27,24 @@ final class VoiceNotePlaybackController: NSObject, ObservableObject, AVAudioPlay
     private var player: AVAudioPlayer?
     private var timer: Timer?
     private var url: URL
+    /// Test seam; `AudioSessionCoordinator.shared` when nil.
+    private let sessionCoordinatorOverride: AudioSessionCoordinator?
+    /// Injectable so tests don't fight over the app-wide exclusive-playback
+    /// slot (a parallel test's `play()` would pause this controller mid-test).
+    private let exclusivity: VoiceNotePlaybackCoordinator
+    private var sessionToken: AudioSessionCoordinator.Token?
+    /// A session acquire is in flight (it suspends off-main for the blocking
+    /// session IPC); gates against double acquisition on rapid play taps.
+    private var sessionAcquireInFlight = false
 
-    init(url: URL) {
+    init(
+        url: URL,
+        sessionCoordinator: AudioSessionCoordinator? = nil,
+        exclusivity: VoiceNotePlaybackCoordinator? = nil
+    ) {
         self.url = url
+        self.sessionCoordinatorOverride = sessionCoordinator
+        self.exclusivity = exclusivity ?? .shared
         super.init()
         // Don't load anything eagerly - wait until user interaction or view is fully displayed
     }
@@ -51,6 +69,16 @@ final class VoiceNotePlaybackController: NSObject, ObservableObject, AVAudioPlay
 
     deinit {
         timer?.invalidate()
+        player?.stop()
+        // A per-row @StateObject can be discarded mid-playback (navigating
+        // away). Leaking the token here would hold the session forever —
+        // never deactivating it, and pinning any escalated category for the
+        // app's lifetime. `release` is fire-and-forget onto the coordinator's
+        // queue, so it is deinit-safe: only the Sendable token crosses.
+        if let token = sessionToken {
+            sessionToken = nil
+            (sessionCoordinatorOverride ?? .shared).release(token)
+        }
     }
 
     func replaceURL(_ url: URL) {
@@ -68,11 +96,15 @@ final class VoiceNotePlaybackController: NSObject, ObservableObject, AVAudioPlay
 
     func play() {
         guard ensurePlayerReady() else { return }
-        VoiceNotePlaybackCoordinator.shared.activate(self)
-        player?.play()
+        exclusivity.activate(self)
+        isPlaying = true
         startTimer()
         updateProgress()
-        isPlaying = true
+        // Acquired here (not in ensurePlayerReady): scrubbing a paused note
+        // must not hold the session while nothing is audible. The session
+        // calls block on audio-server IPC, so they run off the main thread;
+        // the player starts once the session is configured.
+        startPlayerAfterAcquiringSession()
     }
 
     func pause() {
@@ -80,6 +112,7 @@ final class VoiceNotePlaybackController: NSObject, ObservableObject, AVAudioPlay
         stopTimer()
         updateProgress()
         isPlaying = false
+        releaseSession()
     }
 
     func stop() {
@@ -88,7 +121,8 @@ final class VoiceNotePlaybackController: NSObject, ObservableObject, AVAudioPlay
         stopTimer()
         updateProgress()
         isPlaying = false
-        VoiceNotePlaybackCoordinator.shared.deactivate(self)
+        releaseSession()
+        exclusivity.deactivate(self)
     }
 
     func seek(to fraction: Double) {
@@ -96,8 +130,11 @@ final class VoiceNotePlaybackController: NSObject, ObservableObject, AVAudioPlay
         let clamped = max(0, min(1, fraction))
         if let player = player {
             player.currentTime = clamped * player.duration
-            if isPlaying {
-                player.play()
+            // While the session acquire is still in flight, don't start
+            // audio pre-activation — the pending acquire's completion starts
+            // playback (from the new position) once the session resolves.
+            if isPlaying, !sessionAcquireInFlight {
+                startPreparedPlayer()
             }
             updateProgress()
         }
@@ -112,18 +149,20 @@ final class VoiceNotePlaybackController: NSObject, ObservableObject, AVAudioPlay
             self.stopTimer()
             self.updateProgress()
             self.isPlaying = false
-            VoiceNotePlaybackCoordinator.shared.deactivate(self)
+            self.releaseSession()
+            self.exclusivity.deactivate(self)
         }
     }
 
     // MARK: - Private Helpers
 
     private func preparePlayer(for url: URL) {
-        // Prepare player synchronously (only called when playback is requested)
+        // Load metadata synchronously, but do not call prepareToPlay here:
+        // paused scrubbing reaches this path and must not acquire playback
+        // hardware outside the AudioSessionCoordinator token lifetime.
         do {
             let player = try AVAudioPlayer(contentsOf: url)
             player.delegate = self
-            player.prepareToPlay()
             self.player = player
             duration = player.duration
             currentTime = player.currentTime
@@ -141,18 +180,81 @@ final class VoiceNotePlaybackController: NSObject, ObservableObject, AVAudioPlay
         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
     }
 
+    /// All entry points (SwiftUI actions, `pauseForExclusivity`, the
+    /// delegate's main-queue hop) run on the main thread; the acquire itself
+    /// suspends while the blocking session IPC runs on the coordinator's
+    /// queue, and the player starts when it resolves. An acquire failure
+    /// leaves playback stopped: starting without a registered token would
+    /// bypass interruption fan-out and the coordinator's refcount. A
+    /// pause/stop landing mid-acquire hands the token straight back.
+    private func startPlayerAfterAcquiringSession() {
+        if sessionToken != nil {
+            startPreparedPlayer()
+            return
+        }
+        guard !sessionAcquireInFlight else { return }
+        sessionAcquireInFlight = true
+        let coordinator = sessionCoordinatorOverride ?? AudioSessionCoordinator.shared
+        Task { @MainActor [weak self] in
+            var token: AudioSessionCoordinator.Token?
+            do {
+                token = try await coordinator.acquire(.playback) { [weak self] in
+                    self?.pause()
+                }
+            } catch {
+                SecureLogger.error("Failed to activate audio session: \(error)", category: .session)
+            }
+            guard let self else {
+                // The row was discarded while acquiring; deinit had no token
+                // to release yet.
+                token.map(coordinator.release)
+                return
+            }
+            self.sessionAcquireInFlight = false
+            guard self.isPlaying else {
+                // Paused/stopped while the session was activating.
+                token.map(coordinator.release)
+                return
+            }
+            guard let token else {
+                self.failPlaybackStart()
+                return
+            }
+            self.sessionToken = token
+            self.startPreparedPlayer()
+        }
+    }
+
+    @discardableResult
+    private func startPreparedPlayer() -> Bool {
+        guard let player,
+              player.prepareToPlay(),
+              player.play()
+        else {
+            SecureLogger.error("Voice note player refused to start " + url.lastPathComponent, category: .session)
+            failPlaybackStart()
+            return false
+        }
+        return true
+    }
+
+    private func failPlaybackStart() {
+        player?.pause()
+        stopTimer()
+        updateProgress()
+        isPlaying = false
+        releaseSession()
+        exclusivity.deactivate(self)
+    }
+
+    private func releaseSession() {
+        sessionToken.map((sessionCoordinatorOverride ?? .shared).release)
+        sessionToken = nil
+    }
+
     private func startTimer() {
         if timer != nil { return }
         timer = Timer.scheduledTimer(withTimeInterval: 0.05, repeats: true) { [weak self] _ in
@@ -181,25 +283,75 @@ final class VoiceNotePlaybackController: NSObject, ObservableObject, AVAudioPlay
     }
 }
 
-/// Ensures only one voice note plays at a time.
+/// Something that can hold the app's single audio-playback slot and yield it
+/// when another playback starts (voice notes pause; live bursts stop).
+protocol ExclusivePlayback: AnyObject {
+    func pauseForExclusivity()
+}
+
+extension VoiceNotePlaybackController: ExclusivePlayback {
+    func pauseForExclusivity() {
+        pause()
+    }
+}
+
+/// Ensures only one voice playback (note or live burst) runs 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
+    struct Reservation: Equatable {
+        fileprivate let generation: UInt64
     }
 
-    func deactivate(_ controller: VoiceNotePlaybackController) {
+    private weak var activeController: (any ExclusivePlayback)?
+    private weak var latestReservedController: (any ExclusivePlayback)?
+    private var latestReservation = Reservation(generation: 0)
+
+    /// Internal so tests can isolate their own exclusivity slot; the app
+    /// uses `shared`.
+    init() {}
+
+    /// Records playback intent without interrupting audio that is already
+    /// audible. Async starters reserve before suspension, then activate only
+    /// after their audio resource is ready.
+    func reserve(_ controller: any ExclusivePlayback) -> Reservation {
+        latestReservation = Reservation(generation: latestReservation.generation &+ 1)
+        latestReservedController = controller
+        return latestReservation
+    }
+
+    /// Immediate activation for synchronous/user-initiated playback.
+    @discardableResult
+    func activate(_ controller: any ExclusivePlayback) -> Reservation {
+        let reservation = reserve(controller)
+        _ = activate(controller, reservation: reservation)
+        return reservation
+    }
+
+    /// Commits an earlier reservation only when it is still the newest
+    /// playback request. This prevents an older async acquire from stealing
+    /// the floor after a newer play gesture.
+    @discardableResult
+    func activate(_ controller: any ExclusivePlayback, reservation: Reservation) -> Bool {
+        guard isCurrent(reservation, for: controller) else { return false }
+        if activeController === controller {
+            return true
+        }
+        activeController?.pauseForExclusivity()
+        activeController = controller
+        return true
+    }
+
+    func isCurrent(_ reservation: Reservation, for controller: any ExclusivePlayback) -> Bool {
+        latestReservation == reservation && latestReservedController === controller
+    }
+
+    func deactivate(_ controller: any ExclusivePlayback) {
         if activeController === controller {
             activeController = nil
         }
+        if latestReservedController === controller {
+            latestReservedController = nil
+        }
     }
 }

bitchat/Features/voice/VoiceRecorder.swift

@@ -1,22 +1,95 @@
 import Foundation
 import AVFoundation
 
+/// The small surface of `AVAudioRecorder` that `VoiceRecorder` owns. Keeping
+/// it behind a protocol lets lifecycle races be tested without opening the
+/// microphone on the test host.
+protocol VoiceAudioRecording: AnyObject {
+    var isRecording: Bool { get }
+    var isMeteringEnabled: Bool { get set }
+    func prepareToRecord() -> Bool
+    func record(forDuration duration: TimeInterval) -> Bool
+    func stop()
+}
+
+extension AVAudioRecorder: VoiceAudioRecording {}
+
+protocol VoiceAudioRecorderCreating {
+    func makeRecorder(url: URL) throws -> any VoiceAudioRecording
+}
+
+private struct SystemVoiceAudioRecorderFactory: VoiceAudioRecorderCreating {
+    func makeRecorder(url: URL) throws -> any VoiceAudioRecording {
+        let settings: [String: Any] = [
+            AVFormatIDKey: kAudioFormatMPEG4AAC,
+            AVSampleRateKey: 16_000,
+            AVNumberOfChannelsKey: 1,
+            AVEncoderBitRateKey: 16_000
+        ]
+        return try AVAudioRecorder(url: url, settings: settings)
+    }
+}
+
 /// Manages audio capture for mesh voice notes with predictable encoding settings.
 actor VoiceRecorder {
-    enum RecorderError: Error {
+    enum RecorderError: Error, Equatable {
         case microphoneAccessDenied
-        case recorderInitializationFailed
         case recordingInProgress
+        case failedToStartRecording
     }
 
     static let shared = VoiceRecorder()
 
-    private let paddingInterval: TimeInterval = 0.5
-    private let maxRecordingDuration: TimeInterval = 120
     static let minRecordingDuration: TimeInterval = 1
 
-    private var recorder: AVAudioRecorder?
+    /// Identity of one press/hold. Every lifecycle mutation must present the
+    /// same owner that started the recorder, so a stale finish or cancel from
+    /// another hold cannot stop or delete the current recording.
+    final class RecordingOwner: @unchecked Sendable {}
+
+    /// Test-only scheduling seams for lifecycle boundaries that otherwise rely
+    /// on wall-clock sleeps. Production uses the real padding delay.
+    struct TestingHooks: Sendable {
+        let waitForStopPadding: (@Sendable (TimeInterval) async -> Void)?
+
+        init(waitForStopPadding: (@Sendable (TimeInterval) async -> Void)? = nil) {
+            self.waitForStopPadding = waitForStopPadding
+        }
+    }
+
+    private let sessionCoordinator: AudioSessionCoordinator
+    private let recorderFactory: any VoiceAudioRecorderCreating
+    private let permissionGranted: () -> Bool
+    private let paddingInterval: TimeInterval
+    private let maxRecordingDuration: TimeInterval
+    private let outputDirectory: URL?
+    private let testingHooks: TestingHooks
+
+    private var recorder: (any VoiceAudioRecording)?
     private var currentURL: URL?
+    private var sessionToken: AudioSessionCoordinator.Token?
+    private var activeOwner: RecordingOwner?
+    /// True only while `startRecording()` is suspended in session acquire.
+    /// A second start is rejected instead of superseding the first one.
+    private var startInFlight = false
+
+    init(
+        sessionCoordinator: AudioSessionCoordinator = .shared,
+        recorderFactory: any VoiceAudioRecorderCreating = SystemVoiceAudioRecorderFactory(),
+        permissionGranted: (() -> Bool)? = nil,
+        paddingInterval: TimeInterval = 0.5,
+        maxRecordingDuration: TimeInterval = 120,
+        outputDirectory: URL? = nil,
+        testingHooks: TestingHooks = TestingHooks()
+    ) {
+        self.sessionCoordinator = sessionCoordinator
+        self.recorderFactory = recorderFactory
+        self.permissionGranted = permissionGranted ?? Self.hasSystemPermission
+        self.paddingInterval = paddingInterval
+        self.maxRecordingDuration = maxRecordingDuration
+        self.outputDirectory = outputDirectory
+        self.testingHooks = testingHooks
+    }
 
     // MARK: - Permissions
 
@@ -42,82 +115,130 @@ actor VoiceRecorder {
     // MARK: - Recording Lifecycle
 
     @discardableResult
-    func startRecording() throws -> URL {
-        if recorder?.isRecording == true {
+    func startRecording(owner: RecordingOwner) async throws -> URL {
+        if activeOwner != nil {
             throw RecorderError.recordingInProgress
         }
 
-        #if os(iOS)
-        let session = AVAudioSession.sharedInstance()
-        guard session.recordPermission == .granted else {
+        guard permissionGranted() 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
+
+        activeOwner = owner
+        startInFlight = true
+
+        // The acquire suspends while the blocking session IPC runs on the
+        // coordinator's queue (never this actor's thread or main).
+        let token: AudioSessionCoordinator.Token
+        do {
+            token = try await sessionCoordinator.acquire(.capture) { [weak self] in
+                Task { await self?.handleSessionInterruption(for: owner) }
+            }
+        } catch {
+            guard activeOwner === owner else {
+                throw CancellationError()
+            }
+            startInFlight = false
+            activeOwner = nil
+            throw error
         }
-        #endif
 
-        let outputURL = try makeOutputURL()
-        let settings: [String: Any] = [
-            AVFormatIDKey: kAudioFormatMPEG4AAC,
-            AVSampleRateKey: 16_000,
-            AVNumberOfChannelsKey: 1,
-            AVEncoderBitRateKey: 16_000
-        ]
+        // Actor reentrancy: release/cancel may have ended this hold while the
+        // blocking session activation was still in progress.
+        guard activeOwner === owner, startInFlight else {
+            sessionCoordinator.release(token)
+            throw CancellationError()
+        }
+        startInFlight = false
+        sessionToken = token
 
-        let audioRecorder = try AVAudioRecorder(url: outputURL, settings: settings)
-        audioRecorder.isMeteringEnabled = true
-        audioRecorder.prepareToRecord()
-        audioRecorder.record(forDuration: maxRecordingDuration)
+        var outputURL: URL?
+        do {
+            let newURL = try makeOutputURL()
+            outputURL = newURL
+            let audioRecorder = try recorderFactory.makeRecorder(url: newURL)
+            audioRecorder.isMeteringEnabled = true
+            guard audioRecorder.prepareToRecord() else {
+                throw RecorderError.failedToStartRecording
+            }
+            guard audioRecorder.record(forDuration: maxRecordingDuration) else {
+                throw RecorderError.failedToStartRecording
+            }
 
-        recorder = audioRecorder
-        currentURL = outputURL
-        return outputURL
+            recorder = audioRecorder
+            currentURL = newURL
+            return newURL
+        } catch {
+            releaseSessionToken()
+            recorder = nil
+            currentURL = nil
+            activeOwner = nil
+            if let outputURL {
+                try? FileManager.default.removeItem(at: outputURL)
+            }
+            throw error
+        }
     }
 
-    func stopRecording() async -> URL? {
-        guard let recorder, recorder.isRecording else {
-            return currentURL
+    func stopRecording(owner: RecordingOwner) async -> URL? {
+        guard activeOwner === owner else { return nil }
+
+        // `finish()` can race a still-suspended start on a direct caller even
+        // though the UI normally routes quick releases through cancel().
+        if startInFlight {
+            activeOwner = nil
+            startInFlight = false
+            return nil
+        }
+
+        guard let activeRecorder = recorder else {
+            let sessionURL = currentURL
+            releaseSessionToken()
+            currentURL = nil
+            activeOwner = nil
+            return sessionURL
         }
 
         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
+        if activeRecorder.isRecording, paddingInterval > 0 {
+            if let waitForStopPadding = testingHooks.waitForStopPadding {
+                await waitForStopPadding(paddingInterval)
+            } else {
+                try? await Task.sleep(nanoseconds: UInt64(paddingInterval * 1_000_000_000))
+            }
         }
 
+        // Cancellation or interruption may have run during the padding sleep.
+        // Only the recorder whose stop began here may be finalized by it.
+        guard activeOwner === owner,
+              let recorder = self.recorder,
+              recorder === activeRecorder
+        else { return nil }
+
+        if activeRecorder.isRecording {
+            activeRecorder.stop()
+        }
+        releaseSessionToken()
+        self.recorder = nil
+        currentURL = nil
+        activeOwner = nil
+
         return sessionURL
     }
 
-    func cancelRecording() {
+    func cancelRecording(owner: RecordingOwner) async {
+        guard activeOwner === owner else { return }
+
+        // Invalidate ownership before cleanup. An actor-reentrant start whose
+        // session acquire resumes later will observe the mismatch and release
+        // its token without opening the microphone.
+        activeOwner = nil
+        startInFlight = false
         if let recorder, recorder.isRecording {
             recorder.stop()
         }
-        cleanupSession()
+        releaseSessionToken()
         if let currentURL {
             try? FileManager.default.removeItem(at: currentURL)
         }
@@ -125,15 +246,61 @@ actor VoiceRecorder {
         currentURL = nil
     }
 
+    /// Panic is a synchronous security boundary: the caller must know the
+    /// microphone, audio-session lease, and partial file are gone before it
+    /// rotates identities or deletes the media tree. VoiceRecorder is an
+    /// independent actor and this cleanup path never hops to MainActor, so a
+    /// short semaphore join is safe even when invoked by the UI actor.
+    nonisolated
+    func panicCancelSynchronously(owner: RecordingOwner) {
+        let finished = DispatchSemaphore(value: 0)
+        Task {
+            await cancelRecording(owner: owner)
+            finished.signal()
+        }
+        finished.wait()
+    }
+
+    /// The audio session was interrupted (call, Siri) or reconfigured: stop
+    /// the recorder but keep `recorder`/`currentURL` so the caller's pending
+    /// `stopRecording()` still returns the partial note.
+    private func handleSessionInterruption(for owner: RecordingOwner) async {
+        // A callback captured for a released token must never stop a newer
+        // recording. Conversely, an interruption delivered while acquire is
+        // still suspended invalidates that acquire before it can open the mic.
+        guard activeOwner === owner else { return }
+        if startInFlight {
+            activeOwner = nil
+            startInFlight = false
+            return
+        }
+        startInFlight = false
+        if let recorder, recorder.isRecording {
+            recorder.stop()
+        }
+        releaseSessionToken()
+    }
+
     // MARK: - Helpers
 
+    private static func hasSystemPermission() -> Bool {
+        #if os(iOS)
+        AVAudioSession.sharedInstance().recordPermission == .granted
+        #elseif os(macOS)
+        AVCaptureDevice.authorizationStatus(for: .audio) == .authorized
+        #else
+        true
+        #endif
+    }
+
     private func makeOutputURL() throws -> URL {
         let formatter = DateFormatter()
         formatter.dateFormat = "yyyyMMdd_HHmmss"
-        let fileName = "voice_\(formatter.string(from: Date())).m4a"
+        let fileName = "voice_\(formatter.string(from: Date()))_\(UUID().uuidString).m4a"
 
-        let baseDirectory = try applicationFilesDirectory().appendingPathComponent("voicenotes/outgoing", isDirectory: true)
-        try FileManager.default.createDirectory(at: baseDirectory, withIntermediateDirectories: true, attributes: nil)
+        let baseDirectory = try outputDirectory
+            ?? applicationFilesDirectory().appendingPathComponent("voicenotes/outgoing", isDirectory: true)
+        try FileManager.default.createDirectory(at: baseDirectory, withIntermediateDirectories: true, attributes: BLEIncomingFileStore.mediaProtectionAttributes)
         return baseDirectory.appendingPathComponent(fileName)
     }
 
@@ -147,9 +314,11 @@ actor VoiceRecorder {
         #endif
     }
 
-    private func cleanupSession() {
-        #if os(iOS)
-        try? AVAudioSession.sharedInstance().setActive(false, options: .notifyOthersOnDeactivation)
-        #endif
+    /// Fire-and-forget: the coordinator hops the blocking deactivation IPC
+    /// onto its own queue.
+    private func releaseSessionToken() {
+        guard let token = sessionToken else { return }
+        sessionToken = nil
+        sessionCoordinator.release(token)
     }
 }

bitchat/Features/voice/Waveform.swift

@@ -56,12 +56,6 @@ final class WaveformCache {
         }
     }
 
-    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

bitchat/Identity/IdentityModels.swift

@@ -14,18 +14,22 @@
 ///
 /// ## Overview
 /// BitChat's identity system separates concerns across three distinct layers:
-/// 1. **Ephemeral Identity**: Short-lived, rotatable peer IDs for privacy
+/// 1. **Network Identity**: the 8-byte peer ID seen on air
 /// 2. **Cryptographic Identity**: Long-term Noise static keys for security
-/// 3. **Social Identity**: User-assigned names and trust relationships
+/// 3. **Social Identity**: assigned names and trust relationships
 ///
-/// This separation allows users to maintain stable cryptographic identities
-/// while frequently rotating their network identifiers for privacy.
+/// The layers are separate concerns, but they are not independent: the network
+/// identity is *derived* from the cryptographic one, so it does not provide
+/// unlinkability. Rotating peer IDs would be a change to this model, not a
+/// description of it — see the note below.
 ///
 /// ## Three-Layer Architecture
 ///
-/// ### Layer 1: Ephemeral Identity
-/// - Random 8-byte peer IDs that rotate periodically
-/// - Provides network-level privacy and prevents tracking
+/// ### Layer 1: Network Identity
+/// - 8-byte peer ID = first 8 bytes of the Noise static key fingerprint
+/// - **Not ephemeral and not rotating.** It is stable across sessions and
+///   reboots, and changes only when the underlying identity is replaced by a
+///   panic wipe. A passive observer can use it to track a device.
 /// - Changes don't affect cryptographic relationships
 /// - Includes handshake state tracking
 ///
@@ -33,7 +37,7 @@
 /// - Based on Noise Protocol static key pairs
 /// - Fingerprint derived from SHA256 of public key
 /// - Enables end-to-end encryption and authentication
-/// - Persists across peer ID rotations
+/// - The root of the peer ID above, and never rotated on a schedule
 ///
 /// ### Layer 3: Social Identity
 /// - User-assigned names (petnames) for contacts
@@ -44,10 +48,13 @@
 /// ## Privacy Design
 /// The model is designed with privacy-first principles:
 /// - No mandatory persistent storage
-/// - Optional identity caching with user consent
-/// - Ephemeral IDs prevent long-term tracking
+/// - Optional identity caching with explicit consent
 /// - Social mappings stored locally only
 ///
+/// It does **not** currently prevent long-term tracking by a passive radio
+/// observer: the peer ID is stable (Layer 1) and signed announcements carry the
+/// static keys and nickname in cleartext.
+///
 /// ## Trust Model
 /// Four levels of trust:
 /// 1. **Unknown**: New or unverified peers
@@ -56,17 +63,17 @@
 /// 4. **Verified**: Cryptographic verification completed
 ///
 /// ## Identity Resolution
-/// When a peer rotates their ephemeral ID:
+/// When a peer's ID changes (a panic wipe on their side, or a future rotation):
 /// 1. Cryptographic handshake reveals their fingerprint
 /// 2. System looks up social identity by fingerprint
-/// 3. UI seamlessly maintains user relationships
+/// 3. UI seamlessly maintains existing relationships
 /// 4. Historical messages remain properly attributed
 ///
 /// ## Conflict Resolution
 /// Handles edge cases like:
 /// - Multiple peers claiming same nickname
 /// - Nickname changes and conflicts
-/// - Identity rotation during active chats
+/// - Identity replacement during active chats
 /// - Network partitions and rejoins
 ///
 /// ## Usage Example
@@ -85,11 +92,13 @@ import BitFoundation
 
 // MARK: - Three-Layer Identity Model
 
-/// Represents the ephemeral layer of identity - short-lived peer IDs that provide network privacy.
-/// These IDs rotate periodically to prevent tracking while maintaining cryptographic relationships.
+/// Represents the network layer of identity — the peer ID seen on air, plus the
+/// handshake state tracked against it.
+///
+/// Named "ephemeral" for historical reasons; the peer ID is in fact stable,
+/// being derived from the Noise static key fingerprint. It does not rotate and
+/// does not prevent tracking.
 struct EphemeralIdentity {
-    let peerID: PeerID          // 8 random bytes
-    let sessionStart: Date
     var handshakeState: HandshakeState
 }
 
@@ -98,19 +107,18 @@ enum HandshakeState {
     case initiated
     case inProgress
     case completed(fingerprint: String)
-    case failed(reason: String)
 }
 
 /// Represents the cryptographic layer of identity - the stable Noise Protocol static key pair.
-/// This identity persists across ephemeral ID rotations and enables secure communication.
-/// The fingerprint serves as the permanent identifier for a peer's cryptographic identity.
+/// This identity outlives any change to a peer's network ID and enables secure communication.
+/// The fingerprint serves as the permanent identifier for a peer's cryptographic identity, and
+/// its first 8 bytes are the peer ID broadcast on the mesh.
 struct CryptographicIdentity: Codable {
     let fingerprint: String     // SHA256 of public key
     let publicKey: Data         // Noise static public key
     // Optional Ed25519 signing public key (used to authenticate public messages)
     var signingPublicKey: Data? = nil
     let firstSeen: Date
-    let lastHandshake: Date?
 }
 
 /// Represents the social layer of identity - user-assigned names and trust relationships.
@@ -126,11 +134,35 @@ struct SocialIdentity: Codable {
     var notes: String?
 }
 
+/// Trust ladder: unknown → casual → vouched → trusted → verified.
+///
+/// Persistence compatibility: `TrustLevel` is stored by its *String* raw
+/// value ("unknown", "casual", …), not by ordinal position, so inserting
+/// `vouched` mid-ladder cannot corrupt previously persisted values — every
+/// pre-existing case keeps the exact raw value it was written with. The
+/// `vouched` tier is additionally never persisted into `SocialIdentity`
+/// (it's recomputed on read from stored vouches), so downgraded builds never
+/// encounter the unfamiliar raw value.
 enum TrustLevel: String, Codable {
-    case unknown = "unknown"
-    case casual = "casual"
-    case trusted = "trusted"
-    case verified = "verified"
+    case unknown
+    case casual
+    /// Transitively trusted: vouched for by at least one peer *I* verified.
+    /// Derived at read time — never written to persistent storage.
+    case vouched
+    case trusted
+    case verified
+}
+
+// MARK: - Vouching (transitive verification)
+
+/// One accepted vouch: a peer I verified (the voucher) attested that they
+/// verified the vouchee. Validity is recomputed on read — a record only
+/// counts while its voucher remains in `verifiedFingerprints` and its
+/// timestamp is within `VouchAttestation.maxAge` — so unverifying a voucher
+/// silently invalidates the vouches they gave without a cascade delete.
+struct VouchRecord: Codable, Equatable {
+    let voucherFingerprint: String
+    let timestamp: Date
 }
 
 // MARK: - Identity Cache
@@ -141,22 +173,78 @@ enum TrustLevel: String, Codable {
 struct IdentityCache: Codable {
     // Fingerprint -> Social mapping
     var socialIdentities: [String: SocialIdentity] = [:]
-    
+
     // Nickname -> [Fingerprints] reverse index
     // Multiple fingerprints can claim same nickname
     var nicknameIndex: [String: Set<String>] = [:]
-    
+
     // Verified fingerprints (cryptographic proof)
     var verifiedFingerprints: Set<String> = []
-    
+
     // Last interaction timestamps (privacy: optional)
-    var lastInteractions: [String: Date] = [:] 
-    
+    var lastInteractions: [String: Date] = [:]
+
     // Blocked Nostr pubkeys (lowercased hex) for geohash chats
     var blockedNostrPubkeys: Set<String> = []
-    
+
+    // Vouching (transitive verification). All three fields are Optional so
+    // caches persisted before this feature decode cleanly — decodeIfPresent
+    // is used below, and a missing key must not trip the "unreadable cache"
+    // recovery path that discards everything.
+
+    // Vouchee fingerprint -> accepted vouches (capped per vouchee)
+    var vouchesByVouchee: [String: [VouchRecord]]? = nil
+
+    // Peer fingerprint -> when we last sent them a vouch batch (rate limit)
+    var vouchBatchSentAt: [String: Date]? = nil
+
+    // Fingerprint -> when we verified it (orders outgoing vouch batches;
+    // entries verified before this field exists sort as oldest)
+    var verifiedAt: [String: Date]? = nil
+
+    // Stable Noise fingerprints that proved encrypted private-media support
+    // inside an authenticated Noise session. Optional for decoding caches
+    // written before this migration. Entries are monotonic until a panic wipe
+    // so an old/replayed announce cannot silently downgrade a peer.
+    var privateMediaCapableFingerprints: Set<String>? = nil
+
+    // Noise-fingerprint -> Ed25519 announcement key, learned only from the
+    // authenticated peer-state payload. This prevents a self-signed announce
+    // containing a copied public Noise key from replacing a previously bound
+    // public-message signing identity. Optional for old cache compatibility.
+    var authenticatedSigningKeysByFingerprint: [String: Data]? = nil
+
+    // Fingerprint -> Cryptographic identity (noise + pinned signing key).
+    // Persisting the signing-key pin is security-critical: it must survive
+    // app restarts so an attacker cannot replay a known peer's
+    // noiseKey/peerID with their own signing key and be treated as first
+    // contact (TOFU downgrade).
+    var cryptographicIdentities: [String: CryptographicIdentity] = [:]
+
     // Schema version for future migrations
     var version: Int = 1
+
+    init() {}
+
+    // Custom decoding so caches written by older builds (missing newer keys
+    // such as `cryptographicIdentities` or the vouching fields) still load
+    // instead of being discarded. Every field uses decodeIfPresent so a
+    // missing key falls back to its default rather than throwing.
+    init(from decoder: Decoder) throws {
+        let container = try decoder.container(keyedBy: CodingKeys.self)
+        socialIdentities = try container.decodeIfPresent([String: SocialIdentity].self, forKey: .socialIdentities) ?? [:]
+        nicknameIndex = try container.decodeIfPresent([String: Set<String>].self, forKey: .nicknameIndex) ?? [:]
+        verifiedFingerprints = try container.decodeIfPresent(Set<String>.self, forKey: .verifiedFingerprints) ?? []
+        lastInteractions = try container.decodeIfPresent([String: Date].self, forKey: .lastInteractions) ?? [:]
+        blockedNostrPubkeys = try container.decodeIfPresent(Set<String>.self, forKey: .blockedNostrPubkeys) ?? []
+        vouchesByVouchee = try container.decodeIfPresent([String: [VouchRecord]].self, forKey: .vouchesByVouchee)
+        vouchBatchSentAt = try container.decodeIfPresent([String: Date].self, forKey: .vouchBatchSentAt)
+        verifiedAt = try container.decodeIfPresent([String: Date].self, forKey: .verifiedAt)
+        privateMediaCapableFingerprints = try container.decodeIfPresent(Set<String>.self, forKey: .privateMediaCapableFingerprints)
+        authenticatedSigningKeysByFingerprint = try container.decodeIfPresent([String: Data].self, forKey: .authenticatedSigningKeysByFingerprint)
+        cryptographicIdentities = try container.decodeIfPresent([String: CryptographicIdentity].self, forKey: .cryptographicIdentities) ?? [:]
+        version = try container.decodeIfPresent(Int.self, forKey: .version) ?? 1
+    }
 }
 
 //

bitchat/Identity/SecureIdentityStateManager.swift

@@ -108,8 +108,6 @@ protocol SecureIdentityStateManagerProtocol {
     func updateSocialIdentity(_ identity: SocialIdentity)
     
     // MARK: Favorites Management
-    func getFavorites() -> Set<String>
-    func setFavorite(_ fingerprint: String, isFavorite: Bool)
     func isFavorite(fingerprint: String) -> Bool
     
     // MARK: Blocked Users Management
@@ -123,8 +121,7 @@ protocol SecureIdentityStateManagerProtocol {
     
     // MARK: Ephemeral Session Management
     func registerEphemeralSession(peerID: PeerID, handshakeState: HandshakeState)
-    func updateHandshakeState(peerID: PeerID, state: HandshakeState)
-    
+
     // MARK: Cleanup
     func clearAllIdentityData()
     func removeEphemeralSession(peerID: PeerID)
@@ -133,6 +130,24 @@ protocol SecureIdentityStateManagerProtocol {
     func setVerified(fingerprint: String, verified: Bool)
     func isVerified(fingerprint: String) -> Bool
     func getVerifiedFingerprints() -> Set<String>
+
+    // MARK: Vouching (transitive verification)
+    @discardableResult
+    func recordVouch(voucheeFingerprint: String, voucherFingerprint: String, timestamp: Date) -> Bool
+    func validVouchers(for fingerprint: String) -> [VouchRecord]
+    func isVouched(fingerprint: String) -> Bool
+    func lastVouchBatchSent(to fingerprint: String) -> Date?
+    func markVouchBatchSent(to fingerprint: String, at date: Date)
+    func signingPublicKey(forFingerprint fingerprint: String) -> Data?
+    func mostRecentlyVerifiedFingerprints(limit: Int, excluding fingerprint: String) -> [String]
+
+    // MARK: Noise-authenticated announcement identity
+    func bindAuthenticatedSigningPublicKey(_ signingPublicKey: Data, fingerprint: String)
+    func authenticatedSigningPublicKey(forFingerprint fingerprint: String) -> Data?
+
+    // MARK: Private-media downgrade protection
+    func markPrivateMediaCapable(fingerprint: String)
+    func hasObservedPrivateMediaCapability(fingerprint: String) -> Bool
 }
 
 /// Singleton manager for secure identity state persistence and retrieval.
@@ -145,48 +160,106 @@ final class SecureIdentityStateManager: SecureIdentityStateManagerProtocol {
     
     // In-memory state
     private var ephemeralSessions: [PeerID: EphemeralIdentity] = [:]
-    private var cryptographicIdentities: [String: CryptographicIdentity] = [:]
+    // Cryptographic identities (including pinned signing keys) live inside
+    // `cache` so they persist across app restarts; see IdentityCache.
     private var cache: IdentityCache = IdentityCache()
     
     // Thread safety
     private let queue = DispatchQueue(label: "bitchat.identity.state", attributes: .concurrent)
+    private let queueSpecificKey = DispatchSpecificKey<UInt8>()
     
-    // Debouncing for keychain saves
-    private var saveTimer: Timer?
-    private let saveDebounceInterval: TimeInterval = 2.0  // Save at most once every 2 seconds
+    // Pending-save coalescing flag. Reads/writes are serialized on `queue`.
+    //
+    // Persistence is SYNCHRONOUS: every mutating API runs its mutate + encrypt
+    // + keychain write inside `queue.sync(flags: .barrier)`, so when the call
+    // returns the write is already complete and NOTHING is left scheduled on
+    // the queue. This is deliberate — a retained DispatchSourceTimer (the
+    // original design) kept the dispatch machinery alive and prevented the
+    // unit-test process from exiting, and fire-and-forget `queue.async(.barrier)`
+    // (a later design) left a backlog of instrumented barrier saves still
+    // draining when LLVM's `--enable-code-coverage` `atexit` handler dumped
+    // `.profraw`, deadlocking the process at teardown on the constrained CI
+    // runner. Synchronous persistence has zero outstanding dispatch at exit, so
+    // neither failure mode is possible. `pendingSave` is now effectively always
+    // false after any mutation (saveIdentityCache persists inline and clears
+    // it); it remains only as a belt-and-suspenders flag read by `forceSave`
+    // and `deinit`.
     private var pendingSave = false
-    
+
     // Encryption key
     private let encryptionKey: SymmetricKey
+    /// True when `encryptionKey` is a throwaway generated this session because the
+    /// persisted key could not be read (device locked / access denied). In that
+    /// state we must NOT persist (it would overwrite the real cache with data the
+    /// next launch can't decrypt) and must NOT delete the existing cache.
+    private let encryptionKeyIsEphemeral: Bool
     
     init(_ keychain: KeychainManagerProtocol) {
         self.keychain = keychain
-        
-        // Generate or retrieve encryption key from keychain
+
+        // Retrieve (or, only on genuine first run, generate) the cache
+        // encryption key. We MUST distinguish "key doesn't exist yet" from a
+        // transient failure (device locked / access denied): the legacy
+        // getIdentityKey(forKey:) collapses both to nil, and generating+saving a
+        // new key deletes the existing one first — permanently orphaning the
+        // encrypted cache on a launch that merely couldn't read the key.
         let loadedKey: SymmetricKey
-        
-        // Try to load from keychain
-        if let keyData = keychain.getIdentityKey(forKey: encryptionKeyName) {
+        let keyIsEphemeral: Bool
+
+        switch keychain.getIdentityKeyWithResult(forKey: encryptionKeyName) {
+        case .success(let keyData):
             loadedKey = SymmetricKey(data: keyData)
+            keyIsEphemeral = false
             SecureLogger.logKeyOperation(.load, keyType: "identity cache encryption key", success: true)
-        }
-        // Generate new key if needed
-        else {
-            loadedKey = SymmetricKey(size: .bits256)
-            let keyData = loadedKey.withUnsafeBytes { Data($0) }
-            // Save to keychain
+
+        case .itemNotFound:
+            // Genuine first run: generate and persist a new key.
+            let newKey = SymmetricKey(size: .bits256)
+            let keyData = newKey.withUnsafeBytes { Data($0) }
             let saved = keychain.saveIdentityKey(keyData, forKey: encryptionKeyName)
+            loadedKey = newKey
+            // If even the save failed, treat the key as ephemeral so we don't
+            // later try to persist a cache the next launch can't read.
+            keyIsEphemeral = !saved
             SecureLogger.logKeyOperation(.generate, keyType: "identity cache encryption key", success: saved)
+
+        case .deviceLocked, .authenticationFailed, .accessDenied, .otherError:
+            // Transient/critical read failure. Do NOT overwrite the persisted
+            // key. Use a session-only ephemeral key; the real key and cache are
+            // left intact for a healthy launch.
+            SecureLogger.warning("Identity cache key unavailable; using ephemeral key for this session (not persisting)", category: .security)
+            loadedKey = SymmetricKey(size: .bits256)
+            keyIsEphemeral = true
         }
-        
+
         self.encryptionKey = loadedKey
-        
-        // Load identity cache on init
-        loadIdentityCache()
+        self.encryptionKeyIsEphemeral = keyIsEphemeral
+        queue.setSpecific(key: queueSpecificKey, value: 1)
+
+        // Only read the persisted cache when we hold the real key; with an
+        // ephemeral key the decrypt would fail and discard the real cache.
+        if !keyIsEphemeral {
+            loadIdentityCache()
+        }
     }
     
     deinit {
-        forceSave()
+        // Do NOT dispatch onto `queue` here. `deinit` can run on any thread
+        // (including one draining `queue`), and the object is being
+        // deallocated: a `queue.sync` risks a re-entrant same-queue wait
+        // (deadlock) and a `queue.async` schedules work that resurrects `self`
+        // and may not drain before process exit.
+        //
+        // A flush here is redundant anyway: every mutating API already
+        // persists inline within its own barrier, so the keychain is already
+        // up to date. As a queue-free best-effort belt-and-suspenders, only
+        // flush if something is still pending. This is a direct read of
+        // in-hand state — safe because a deallocating object has no other
+        // live references, so nothing can be mutating `cache` concurrently.
+        if pendingSave {
+            pendingSave = false
+            persist(snapshot: cache)
+        }
     }
     
     // MARK: - Secure Loading/Saving
@@ -211,25 +284,36 @@ final class SecureIdentityStateManager: SecureIdentityStateManagerProtocol {
         }
     }
     
+    /// Persists the cache. Always invoked on `queue` under a barrier (its
+    /// callers run inside `queue.sync(flags: .barrier)`), so `cache` is read
+    /// while serialized. The encode + keychain write are done here (already on
+    /// the exclusive barrier context), synchronously, so no separate hop is
+    /// scheduled and nothing is left to keep the process alive.
     private func saveIdentityCache() {
-        // Mark that we need to save
         pendingSave = true
-        
-        // Cancel any existing timer
-        saveTimer?.invalidate()
-        
-        // Schedule a new save after the debounce interval
-        saveTimer = Timer.scheduledTimer(withTimeInterval: saveDebounceInterval, repeats: false) { [weak self] _ in
-            self?.performSave()
-        }
-    }
-    
-    private func performSave() {
-        guard pendingSave else { return }
+        // On the barrier context already: snapshot is trivially consistent.
+        persist(snapshot: cache)
         pendingSave = false
-        
+    }
+
+    /// Encodes, seals, and writes a *snapshot* of the cache to the keychain.
+    ///
+    /// Takes the cache by value so callers can capture a consistent snapshot
+    /// under `queue` and then encode without holding it. Reading `cache`
+    /// concurrently with a barrier writer would be a data race on the
+    /// dictionary storage, which — because `JSONEncoder` walks that storage —
+    /// can spin forever (observed as a CI test-suite hang), so the snapshot
+    /// must be taken on `queue`, never off it.
+    private func persist(snapshot: IdentityCache) {
+        // Never persist under an ephemeral key — it would overwrite the real
+        // cache with data the next launch cannot decrypt.
+        guard !encryptionKeyIsEphemeral else {
+            SecureLogger.debug("Skipping identity cache save (ephemeral key this session)", category: .security)
+            return
+        }
+
         do {
-            let data = try JSONEncoder().encode(cache)
+            let data = try JSONEncoder().encode(snapshot)
             let sealedBox = try AES.GCM.seal(data, using: encryptionKey)
             let saved = keychain.saveIdentityKey(sealedBox.combined!, forKey: cacheKey)
             if saved {
@@ -239,11 +323,27 @@ final class SecureIdentityStateManager: SecureIdentityStateManagerProtocol {
             SecureLogger.error(error, context: "Failed to save identity cache", category: .security)
         }
     }
-    
-    // Force immediate save (for app termination)
+
+    // Force a flush (for app-termination / lifecycle events — NOT from
+    // `deinit`, which persists inline; see the deinit note). Every mutating
+    // API already persists inline inside its own barrier via
+    // `saveIdentityCache`, so by the time this is called the keychain is
+    // already up to date and this is normally a no-op; it exists as a
+    // belt-and-suspenders flush of any `pendingSave` left set.
+    //
+    // Runs synchronously inside a `queue.sync(flags: .barrier)`: the barrier
+    // makes the `cache` read race-free (a plain off-queue read races in-flight
+    // barrier writers — JSONEncoder walking a concurrently-mutated dictionary
+    // can spin forever, which surfaced as a CI hang), and being synchronous it
+    // leaves nothing scheduled to keep the process alive at teardown. Safe
+    // against re-entrant deadlock because this is never invoked from `deinit`
+    // (the only path that can run *on* `queue`).
     func forceSave() {
-        saveTimer?.invalidate()
-        performSave()
+        queue.sync(flags: .barrier) {
+            guard pendingSave else { return }
+            pendingSave = false
+            persist(snapshot: cache)
+        }
     }
     
     // MARK: - Social Identity Management
@@ -257,36 +357,46 @@ final class SecureIdentityStateManager: SecureIdentityStateManagerProtocol {
     // MARK: - Cryptographic Identities
 
     /// Insert or update a cryptographic identity and optionally persist its signing key and claimed nickname.
+    ///
+    /// TOFU signing-key pinning: once a signing key has been persisted for a
+    /// fingerprint, an update carrying a *different* signing key is refused in
+    /// full (including the claimed-nickname update) and security-logged. This
+    /// mirrors `BLEPeerRegistry.upsertVerifiedAnnounce` — without it, an
+    /// attacker replaying a victim's noiseKey/peerID with their own signing
+    /// key could overwrite the victim's persisted identity while the victim is
+    /// offline or after an app restart. The refusal is permanent: there is
+    /// currently no targeted in-app way to reset the pin (`setVerified` does
+    /// not touch it). Recovering from a legitimate signing re-key requires the
+    /// peer to establish a new noise identity (new peerID) or the local user
+    /// to wipe all identity data (`clearAllIdentityData`, e.g. panic wipe).
     /// - Parameters:
     ///   - fingerprint: SHA-256 hex of the Noise static public key
     ///   - noisePublicKey: Noise static public key data
     ///   - signingPublicKey: Optional Ed25519 signing public key for authenticating public messages
     ///   - claimedNickname: Optional latest claimed nickname to persist into social identity
     func upsertCryptographicIdentity(fingerprint: String, noisePublicKey: Data, signingPublicKey: Data?, claimedNickname: String? = nil) {
-        queue.async(flags: .barrier) {
+        queue.sync(flags: .barrier) {
             let now = Date()
-            if var existing = self.cryptographicIdentities[fingerprint] {
+            if var existing = self.cache.cryptographicIdentities[fingerprint] {
+                if let pinnedSigningKey = existing.signingPublicKey,
+                   let announcedSigningKey = signingPublicKey,
+                   pinnedSigningKey != announcedSigningKey {
+                    SecureLogger.warning("🚨 Refusing to replace pinned signing key for \(fingerprint.prefix(8))… (possible impersonation attempt)", category: .security)
+                    return
+                }
                 // Update keys if changed
                 if existing.publicKey != noisePublicKey {
                     existing = CryptographicIdentity(
                         fingerprint: fingerprint,
                         publicKey: noisePublicKey,
                         signingPublicKey: signingPublicKey ?? existing.signingPublicKey,
-                        firstSeen: existing.firstSeen,
-                        lastHandshake: now
+                        firstSeen: existing.firstSeen
                     )
-                    self.cryptographicIdentities[fingerprint] = existing
+                    self.cache.cryptographicIdentities[fingerprint] = existing
                 } else {
-                    // Update signing key and lastHandshake
+                    // Update signing key
                     existing.signingPublicKey = signingPublicKey ?? existing.signingPublicKey
-                    let updated = CryptographicIdentity(
-                        fingerprint: existing.fingerprint,
-                        publicKey: existing.publicKey,
-                        signingPublicKey: existing.signingPublicKey,
-                        firstSeen: existing.firstSeen,
-                        lastHandshake: now
-                    )
-                    self.cryptographicIdentities[fingerprint] = updated
+                    self.cache.cryptographicIdentities[fingerprint] = existing
                 }
                 // Persist updated state (already assigned in branches above)
             } else {
@@ -295,10 +405,9 @@ final class SecureIdentityStateManager: SecureIdentityStateManagerProtocol {
                     fingerprint: fingerprint,
                     publicKey: noisePublicKey,
                     signingPublicKey: signingPublicKey,
-                    firstSeen: now,
-                    lastHandshake: now
+                    firstSeen: now
                 )
-                self.cryptographicIdentities[fingerprint] = entry
+                self.cache.cryptographicIdentities[fingerprint] = entry
             }
 
             // Optionally persist claimed nickname into social identity
@@ -330,12 +439,72 @@ final class SecureIdentityStateManager: SecureIdentityStateManagerProtocol {
         queue.sync {
             // Defensive: ensure hex and correct length
             guard peerID.isShort else { return [] }
-            return cryptographicIdentities.values.filter { $0.fingerprint.hasPrefix(peerID.id) }
+            return cache.cryptographicIdentities.values.filter { $0.fingerprint.hasPrefix(peerID.id) }
+        }
+    }
+
+    // MARK: - Private-media downgrade protection
+
+    func markPrivateMediaCapable(fingerprint: String) {
+        guard !fingerprint.isEmpty else { return }
+        let insertAndPersist = {
+            var pinned = self.cache.privateMediaCapableFingerprints ?? []
+            guard pinned.insert(fingerprint).inserted else { return }
+            self.cache.privateMediaCapableFingerprints = pinned
+            self.saveIdentityCache()
+        }
+        // Downgrade decisions can run immediately after an authenticated
+        // announce. Make the pin visible before returning; merely enqueueing a
+        // barrier leaves a cross-queue window where a replay can look legacy.
+        // The queue-specific fast path prevents self-deadlock if a future
+        // identity-state mutation records the capability from inside `queue`.
+        if DispatchQueue.getSpecific(key: queueSpecificKey) != nil {
+            insertAndPersist()
+        } else {
+            queue.sync(flags: .barrier, execute: insertAndPersist)
+        }
+    }
+
+    func hasObservedPrivateMediaCapability(fingerprint: String) -> Bool {
+        guard !fingerprint.isEmpty else { return false }
+        return queue.sync {
+            cache.privateMediaCapableFingerprints?.contains(fingerprint) == true
+        }
+    }
+
+    // MARK: - Noise-authenticated announcement identity
+
+    func bindAuthenticatedSigningPublicKey(_ signingPublicKey: Data, fingerprint: String) {
+        guard signingPublicKey.count == AuthenticatedPeerStatePacket.signingPublicKeyLength,
+              !fingerprint.isEmpty else { return }
+        let bindAndPersist = {
+            var bindings = self.cache.authenticatedSigningKeysByFingerprint ?? [:]
+            let bindingChanged = bindings[fingerprint] != signingPublicKey
+            bindings[fingerprint] = signingPublicKey
+            self.cache.authenticatedSigningKeysByFingerprint = bindings
+            if var cryptoIdentity = self.cache.cryptographicIdentities[fingerprint] {
+                cryptoIdentity.signingPublicKey = signingPublicKey
+                self.cache.cryptographicIdentities[fingerprint] = cryptoIdentity
+            }
+            guard bindingChanged else { return }
+            self.saveIdentityCache()
+        }
+        if DispatchQueue.getSpecific(key: queueSpecificKey) != nil {
+            bindAndPersist()
+        } else {
+            queue.sync(flags: .barrier, execute: bindAndPersist)
+        }
+    }
+
+    func authenticatedSigningPublicKey(forFingerprint fingerprint: String) -> Data? {
+        guard !fingerprint.isEmpty else { return nil }
+        return queue.sync {
+            cache.authenticatedSigningKeysByFingerprint?[fingerprint]
         }
     }
     
     func updateSocialIdentity(_ identity: SocialIdentity) {
-        queue.async(flags: .barrier) {
+        queue.sync(flags: .barrier) {
             let previousClaimedNickname = self.cache.socialIdentities[identity.fingerprint]?.claimedNickname
             self.cache.socialIdentities[identity.fingerprint] = identity
             
@@ -371,7 +540,7 @@ final class SecureIdentityStateManager: SecureIdentityStateManagerProtocol {
     }
     
     func setFavorite(_ fingerprint: String, isFavorite: Bool) {
-        queue.async(flags: .barrier) {
+        queue.sync(flags: .barrier) {
             if var identity = self.cache.socialIdentities[fingerprint] {
                 identity.isFavorite = isFavorite
                 self.cache.socialIdentities[fingerprint] = identity
@@ -409,7 +578,7 @@ final class SecureIdentityStateManager: SecureIdentityStateManagerProtocol {
     func setBlocked(_ fingerprint: String, isBlocked: Bool) {
         SecureLogger.info("User \(isBlocked ? "blocked" : "unblocked"): \(fingerprint)", category: .security)
         
-        queue.async(flags: .barrier) {
+        queue.sync(flags: .barrier) {
             if var identity = self.cache.socialIdentities[fingerprint] {
                 identity.isBlocked = isBlocked
                 if isBlocked {
@@ -443,7 +612,7 @@ final class SecureIdentityStateManager: SecureIdentityStateManagerProtocol {
     
     func setNostrBlocked(_ pubkeyHexLowercased: String, isBlocked: Bool) {
         let key = pubkeyHexLowercased.lowercased()
-        queue.async(flags: .barrier) {
+        queue.sync(flags: .barrier) {
             if isBlocked {
                 self.cache.blockedNostrPubkeys.insert(key)
             } else {
@@ -461,16 +630,12 @@ final class SecureIdentityStateManager: SecureIdentityStateManagerProtocol {
     
     func registerEphemeralSession(peerID: PeerID, handshakeState: HandshakeState = .none) {
         queue.async(flags: .barrier) {
-            self.ephemeralSessions[peerID] = EphemeralIdentity(
-                peerID: peerID,
-                sessionStart: Date(),
-                handshakeState: handshakeState
-            )
+            self.ephemeralSessions[peerID] = EphemeralIdentity(handshakeState: handshakeState)
         }
     }
     
     func updateHandshakeState(peerID: PeerID, state: HandshakeState) {
-        queue.async(flags: .barrier) {
+        queue.sync(flags: .barrier) {
             self.ephemeralSessions[peerID]?.handshakeState = state
             
             // If handshake completed, update last interaction
@@ -486,11 +651,10 @@ final class SecureIdentityStateManager: SecureIdentityStateManagerProtocol {
     func clearAllIdentityData() {
         SecureLogger.warning("Clearing all identity data", category: .security)
         
-        queue.async(flags: .barrier) {
+        queue.sync(flags: .barrier) {
             self.cache = IdentityCache()
             self.ephemeralSessions.removeAll()
-            self.cryptographicIdentities.removeAll()
-            
+
             // Delete from keychain
             let deleted = self.keychain.deleteIdentityKey(forKey: self.cacheKey)
             SecureLogger.logKeyOperation(.delete, keyType: "identity cache", success: deleted)
@@ -498,8 +662,8 @@ final class SecureIdentityStateManager: SecureIdentityStateManagerProtocol {
     }
     
     func removeEphemeralSession(peerID: PeerID) {
-        queue.async(flags: .barrier) {
-            self.ephemeralSessions.removeValue(forKey: peerID)
+        queue.sync(flags: .barrier) {
+            _ = self.ephemeralSessions.removeValue(forKey: peerID)
         }
     }
     
@@ -508,19 +672,23 @@ final class SecureIdentityStateManager: SecureIdentityStateManagerProtocol {
     func setVerified(fingerprint: String, verified: Bool) {
         SecureLogger.info("Fingerprint \(verified ? "verified" : "unverified"): \(fingerprint)", category: .security)
         
-        queue.async(flags: .barrier) {
+        queue.sync(flags: .barrier) {
             if verified {
                 self.cache.verifiedFingerprints.insert(fingerprint)
+                var verifiedAt = self.cache.verifiedAt ?? [:]
+                verifiedAt[fingerprint] = Date()
+                self.cache.verifiedAt = verifiedAt
             } else {
                 self.cache.verifiedFingerprints.remove(fingerprint)
+                self.cache.verifiedAt?.removeValue(forKey: fingerprint)
             }
-            
+
             // Update trust level if social identity exists
             if var identity = self.cache.socialIdentities[fingerprint] {
                 identity.trustLevel = verified ? .verified : .casual
                 self.cache.socialIdentities[fingerprint] = identity
             }
-            
+
             self.saveIdentityCache()
         }
     }
@@ -537,6 +705,159 @@ final class SecureIdentityStateManager: SecureIdentityStateManagerProtocol {
         }
     }
 
+    // MARK: - Vouching (transitive verification)
+
+    /// Maximum vouchers retained per vouchee (most recent kept).
+    static let maxVouchersPerVouchee = 8
+
+    /// Records an accepted vouch, enforcing every accept-policy gate that can
+    /// be evaluated against stored state (signature verification is the
+    /// caller's job — it needs the sender's announce-bound signing key):
+    /// - the voucher must be a fingerprint *I* verified
+    /// - self-vouches are ignored
+    /// - vouches for peers I already verified are ignored (nothing to add)
+    /// - attestations outside the validity window are ignored
+    /// - at most `maxVouchersPerVouchee` vouchers are kept per vouchee
+    ///
+    /// Returns true when the vouch was stored (or refreshed).
+    @discardableResult
+    func recordVouch(voucheeFingerprint: String, voucherFingerprint: String, timestamp: Date) -> Bool {
+        recordVouch(
+            voucheeFingerprint: voucheeFingerprint,
+            voucherFingerprint: voucherFingerprint,
+            timestamp: timestamp,
+            now: Date()
+        )
+    }
+
+    @discardableResult
+    func recordVouch(voucheeFingerprint: String, voucherFingerprint: String, timestamp: Date, now: Date) -> Bool {
+        queue.sync(flags: .barrier) {
+            guard voucheeFingerprint != voucherFingerprint,
+                  self.cache.verifiedFingerprints.contains(voucherFingerprint),
+                  !self.cache.verifiedFingerprints.contains(voucheeFingerprint) else {
+                return false
+            }
+            let age = now.timeIntervalSince(timestamp)
+            guard age <= VouchAttestation.maxAge, age >= -VouchAttestation.maxClockSkew else {
+                return false
+            }
+
+            var records = self.cache.vouchesByVouchee?[voucheeFingerprint] ?? []
+            if let index = records.firstIndex(where: { $0.voucherFingerprint == voucherFingerprint }) {
+                let newest = max(records[index].timestamp, timestamp)
+                records[index] = VouchRecord(voucherFingerprint: voucherFingerprint, timestamp: newest)
+            } else {
+                records.append(VouchRecord(voucherFingerprint: voucherFingerprint, timestamp: timestamp))
+            }
+            // Keep the most recent vouchers up to the cap.
+            records.sort { $0.timestamp > $1.timestamp }
+            let capped = Array(records.prefix(Self.maxVouchersPerVouchee))
+            guard capped.contains(where: { $0.voucherFingerprint == voucherFingerprint }) else {
+                return false // Full of fresher vouches; nothing changed.
+            }
+
+            var vouches = self.cache.vouchesByVouchee ?? [:]
+            vouches[voucheeFingerprint] = capped
+            self.cache.vouchesByVouchee = vouches
+            self.saveIdentityCache()
+            return true
+        }
+    }
+
+    /// The vouches that currently count for `fingerprint`. Validity is
+    /// recomputed here rather than maintained by cascade deletes: a record
+    /// only counts while its voucher is still verified-by-me and its
+    /// timestamp is within the expiry window.
+    func validVouchers(for fingerprint: String) -> [VouchRecord] {
+        validVouchers(for: fingerprint, now: Date())
+    }
+
+    func validVouchers(for fingerprint: String, now: Date) -> [VouchRecord] {
+        queue.sync {
+            self.validVouchersLocked(for: fingerprint, now: now)
+        }
+    }
+
+    /// Requires `queue`.
+    private func validVouchersLocked(for fingerprint: String, now: Date) -> [VouchRecord] {
+        guard let records = cache.vouchesByVouchee?[fingerprint] else { return [] }
+        return records.filter { record in
+            record.voucherFingerprint != fingerprint
+                && cache.verifiedFingerprints.contains(record.voucherFingerprint)
+                && now.timeIntervalSince(record.timestamp) <= VouchAttestation.maxAge
+        }
+    }
+
+    /// True when the peer has at least one valid vouch and no explicit
+    /// verification of ours.
+    func isVouched(fingerprint: String) -> Bool {
+        isVouched(fingerprint: fingerprint, now: Date())
+    }
+
+    func isVouched(fingerprint: String, now: Date) -> Bool {
+        queue.sync {
+            guard !self.cache.verifiedFingerprints.contains(fingerprint) else { return false }
+            return !self.validVouchersLocked(for: fingerprint, now: now).isEmpty
+        }
+    }
+
+    /// The trust level to display: explicit verification wins, then the
+    /// persisted level, with `vouched` layered in (derived, never persisted)
+    /// between `casual` and `trusted`.
+    func effectiveTrustLevel(for fingerprint: String) -> TrustLevel {
+        effectiveTrustLevel(for: fingerprint, now: Date())
+    }
+
+    func effectiveTrustLevel(for fingerprint: String, now: Date) -> TrustLevel {
+        queue.sync {
+            if self.cache.verifiedFingerprints.contains(fingerprint) { return .verified }
+            let stored = self.cache.socialIdentities[fingerprint]?.trustLevel ?? .unknown
+            let vouched = !self.validVouchersLocked(for: fingerprint, now: now).isEmpty
+            switch stored {
+            case .verified, .trusted:
+                return stored
+            case .vouched, .casual, .unknown:
+                if vouched { return .vouched }
+                // `.vouched` should never be persisted; degrade defensively.
+                return stored == .vouched ? .casual : stored
+            }
+        }
+    }
+
+    func lastVouchBatchSent(to fingerprint: String) -> Date? {
+        queue.sync { cache.vouchBatchSentAt?[fingerprint] }
+    }
+
+    func markVouchBatchSent(to fingerprint: String, at date: Date) {
+        queue.async(flags: .barrier) {
+            var sentAt = self.cache.vouchBatchSentAt ?? [:]
+            sentAt[fingerprint] = date
+            self.cache.vouchBatchSentAt = sentAt
+            self.saveIdentityCache()
+        }
+    }
+
+    /// The peer's announce-bound Ed25519 signing key, if seen this session.
+    func signingPublicKey(forFingerprint fingerprint: String) -> Data? {
+        queue.sync { cache.cryptographicIdentities[fingerprint]?.signingPublicKey }
+    }
+
+    /// Verified fingerprints ordered most recently verified first (entries
+    /// without a recorded verification time sort last), excluding the given
+    /// fingerprint. Feeds the outgoing vouch batch.
+    func mostRecentlyVerifiedFingerprints(limit: Int, excluding fingerprint: String) -> [String] {
+        queue.sync {
+            let verifiedAt = cache.verifiedAt ?? [:]
+            let ordered = cache.verifiedFingerprints
+                .filter { $0 != fingerprint }
+                .sorted {
+                    (verifiedAt[$0] ?? .distantPast, $0) > (verifiedAt[$1] ?? .distantPast, $1)
+                }
+            return Array(ordered.prefix(limit))
+        }
+    }
+
     var debugNicknameIndex: [String: Set<String>] {
         queue.sync { cache.nicknameIndex }
     }

bitchat/Info.plist

@@ -31,6 +31,8 @@
 	</array>
 	<key>CFBundleVersion</key>
 	<string>$(CURRENT_PROJECT_VERSION)</string>
+	<key>LSApplicationCategoryType</key>
+	<string>public.app-category.social-networking</string>
 	<key>LSMinimumSystemVersion</key>
 	<string>$(MACOSX_DEPLOYMENT_TARGET)</string>
 	<key>NSBluetoothAlwaysUsageDescription</key>
@@ -40,9 +42,9 @@
 	<key>NSCameraUsageDescription</key>
 	<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>
+	<string>bitchat uses your location to compute optional geohash channels, bridge cells, and nearby place labels. Exact coordinates are not included in bitchat messages.</string>
 	<key>NSMicrophoneUsageDescription</key>
-	<string>bitchat uses the microphone to record voice notes that relay across the mesh.</string>
+	<string>bitchat uses the microphone while you record voice notes or hold live push-to-talk, then sends that audio to your selected mesh conversation.</string>
 	<key>NSPhotoLibraryUsageDescription</key>
 	<string>bitchat lets you pick images from your photo library to share with nearby peers.</string>
 	<key>UIBackgroundModes</key>

bitchat/Models/BitchatMessage+Media.swift

@@ -13,13 +13,6 @@ 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
@@ -31,7 +24,7 @@ extension BitchatMessage {
             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)
+                try FileManager.default.createDirectory(at: filesDir, withIntermediateDirectories: true, attributes: BLEIncomingFileStore.mediaProtectionAttributes)
                 self.filesDir = filesDir
             } catch {
                 filesDir = nil

bitchat/Models/BitchatPeer.swift

@@ -7,7 +7,6 @@ struct BitchatPeer: Equatable {
     let peerID: PeerID // Hex-encoded peer ID
     let noisePublicKey: Data
     let nickname: String
-    let lastSeen: Date
     let isConnected: Bool
     let isReachable: Bool
     
@@ -16,6 +15,10 @@ struct BitchatPeer: Equatable {
     
     // Nostr identity (if known)
     var nostrPublicKey: String?
+
+    /// Device-local alias (petname). Never sent over the wire; when set it
+    /// outranks the peer-claimed `nickname` for display only.
+    var localPetname: String?
     
     // Connection state
     enum ConnectionState {
@@ -30,13 +33,22 @@ struct BitchatPeer: Equatable {
             return .bluetoothConnected
         } else if isReachable {
             return .meshReachable
-        } else if favoriteStatus?.isMutual == true {
-            // Mutual favorites can communicate via Nostr when offline
+        } else if favoriteStatus?.isMutual == true, reachableNostrPublicKey != nil {
+            // Mutual favorites can communicate via Nostr when offline — but
+            // only with a stored recipient key. NostrTransport applies the
+            // same rule when computing reachable peers; without a key,
+            // "available" would be a lie, and the DM header's
+            // "end-to-end encrypted" caption keys off this state.
             return .nostrAvailable
         } else {
             return .offline
         }
     }
+
+    /// The Nostr key a private envelope would actually be sealed to, if any.
+    var reachableNostrPublicKey: String? {
+        nostrPublicKey ?? favoriteStatus?.peerNostrPublicKey
+    }
     
     var isFavorite: Bool {
         favoriteStatus?.isFavorite ?? false
@@ -52,7 +64,10 @@ struct BitchatPeer: Equatable {
     
     // Display helpers
     var displayName: String {
-        nickname.isEmpty ? String(peerID.id.prefix(8)) : nickname
+        if let localPetname, !localPetname.isEmpty {
+            return localPetname
+        }
+        return nickname.isEmpty ? String(peerID.id.prefix(8)) : nickname
     }
     
     var statusIcon: String {
@@ -77,16 +92,17 @@ struct BitchatPeer: Equatable {
         peerID: PeerID,
         noisePublicKey: Data,
         nickname: String,
-        lastSeen: Date = Date(),
+        lastSeen _: Date = Date(),
         isConnected: Bool = false,
-        isReachable: Bool = false
+        isReachable: Bool = false,
+        localPetname: String? = nil
     ) {
         self.peerID = peerID
         self.noisePublicKey = noisePublicKey
         self.nickname = nickname
-        self.lastSeen = lastSeen
         self.isConnected = isConnected
         self.isReachable = isReachable
+        self.localPetname = localPetname
         
         // Load favorite status - will be set later by the manager
         self.favoriteStatus = nil

bitchat/Models/CommandInfo.swift

@@ -11,48 +11,78 @@ import Foundation
 // MARK: - CommandInfo Enum
 
 enum CommandInfo: String, Identifiable {
+    // Raw values must match the aliases CommandProcessor actually accepts —
+    // the suggestion panel is the app's only command-discovery surface, and
+    // suggesting a spelling the processor rejects teaches users dead ends.
     case block
     case clear
+    case group
+    case help
     case hug
-    case message = "dm"
+    case message = "msg"
     case slap
+    case pay
     case unblock
     case who
-    case favorite
-    case unfavorite
-    
+    case favorite = "fav"
+    case unfavorite = "unfav"
+    case ping
+    case trace
+    case drop
+
     var id: String { rawValue }
-    
+
     var alias: String { "/" + rawValue }
-    
+
     var placeholder: String? {
         switch self {
-        case .block, .hug, .message, .slap, .unblock, .favorite, .unfavorite:
+        case .block, .hug, .message, .slap, .unblock, .favorite, .unfavorite, .ping, .trace:
             return "<" + String(localized: "content.input.nickname_placeholder") + ">"
-        case .clear, .who:
+        case .group:
+            return "<" + String(localized: "content.input.group_placeholder") + ">"
+        case .pay:
+            return "<" + String(localized: "content.input.token_placeholder") + ">"
+        case .drop:
+            return "<" + String(localized: "content.input.note_placeholder") + ">"
+        case .clear, .help, .who:
             return nil
         }
     }
-    
+
     var description: String {
         switch self {
         case .block:        String(localized: "content.commands.block")
         case .clear:        String(localized: "content.commands.clear")
+        case .group:        String(localized: "content.commands.group")
+        case .help:         String(localized: "content.commands.help")
         case .hug:          String(localized: "content.commands.hug")
         case .message:      String(localized: "content.commands.message")
+        case .pay:          String(localized: "content.commands.pay")
         case .slap:         String(localized: "content.commands.slap")
         case .unblock:      String(localized: "content.commands.unblock")
         case .who:          String(localized: "content.commands.who")
         case .favorite:     String(localized: "content.commands.favorite")
         case .unfavorite:   String(localized: "content.commands.unfavorite")
+        case .ping:         String(localized: "content.commands.ping")
+        case .trace:        String(localized: "content.commands.trace")
+        case .drop:         String(localized: "content.commands.drop")
         }
     }
-    
+
     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]
+        var commands: [CommandInfo] = [.block, .unblock, .clear, .drop, .help, .hug, .message, .slap, .who]
+        // Cashu tokens are bearer instruments: in a public geohash any nearby
+        // stranger can redeem one, so don't *suggest* /pay there (the
+        // processor still allows it behind an explicit "public" confirm).
+        // Payments make sense in every DM and in mesh public.
+        if !isGeoPublic {
+            commands.append(.pay)
         }
-        return baseCommands
+        // The processor rejects favorites, groups, and mesh diagnostics in
+        // geohash contexts, so only suggest them where they work: mesh.
+        if isGeoPublic || isGeoDM {
+            return commands
+        }
+        return commands + [.favorite, .unfavorite, .ping, .trace, .group]
     }
 }

bitchat/Models/NoisePayload.swift

@@ -30,7 +30,7 @@ struct NoisePayload {
         
         // Safely get the first byte
         let firstByte = data[data.startIndex]
-        guard let type = NoisePayloadType(rawValue: firstByte) else {
+        guard let type = NoisePayloadType.decoded(rawValue: firstByte) else {
             return nil
         }
         

bitchat/Models/RequestSyncPacket.swift

@@ -1,10 +1,21 @@
+import BitFoundation
 import Foundation
 
 // REQUEST_SYNC payload TLV (type, length16, value)
 //  - 0x01: P (uint8) — Golomb-Rice parameter
 //  - 0x02: M (uint32, big-endian) — hash range (N * 2^P)
 //  - 0x03: data (opaque) — GR bitstream bytes (MSB-first)
+//  - 0x04: types (SyncTypeFlags) — packet types the filter covers
+//  - 0x05: sinceTimestamp (uint64, big-endian) — filter coverage cursor
+//  - 0x06: fragmentIdFilter (UTF-8) — comma-separated 16-hex-char (8-byte)
+//          fragment stream IDs; restricts the fragment diff to exactly those
+//          streams (targeted resync for stalled reassemblies)
 struct RequestSyncPacket {
+    /// Maximum fragment IDs one 0x06 filter may carry. Each ID encodes as
+    /// 16 hex chars plus a comma separator, so the largest encoded value is
+    /// 60 * 17 - 1 = 1019 bytes, which fits the 1024-byte decoder cap.
+    static let maxFragmentIdFilterCount = 60
+
     let p: Int
     let m: UInt32
     let data: Data
@@ -12,6 +23,29 @@ struct RequestSyncPacket {
     let sinceTimestamp: UInt64?
     let fragmentIdFilter: String?
 
+    /// Encodes 8-byte fragment stream IDs as the 0x06 filter string,
+    /// dropping malformed IDs and capping at `maxFragmentIdFilterCount`.
+    static func encodeFragmentIdFilter(_ fragmentIDs: [Data]) -> String? {
+        let tokens = fragmentIDs
+            .filter { $0.count == 8 }
+            .prefix(maxFragmentIdFilterCount)
+            .map { $0.hexEncodedString() }
+        guard !tokens.isEmpty else { return nil }
+        return tokens.joined(separator: ",")
+    }
+
+    /// Decodes a 0x06 filter string back into 8-byte fragment stream IDs,
+    /// ignoring malformed tokens and capping at `maxFragmentIdFilterCount`.
+    static func decodeFragmentIdFilter(_ filter: String?) -> Set<Data>? {
+        guard let filter else { return nil }
+        var ids: Set<Data> = []
+        for token in filter.split(separator: ",").prefix(maxFragmentIdFilterCount) {
+            guard token.count == 16, let id = Data(hexString: String(token)) else { continue }
+            ids.insert(id)
+        }
+        return ids.isEmpty ? nil : ids
+    }
+
     init(p: Int, m: UInt32, data: Data, types: SyncTypeFlags? = nil, sinceTimestamp: UInt64? = nil, fragmentIdFilter: String? = nil) {
         self.p = p
         self.m = m
@@ -88,7 +122,9 @@ struct RequestSyncPacket {
                     sinceTimestamp = ts
                 }
             case 0x06:
-                if let fid = String(data: v, encoding: .utf8) {
+                // Same acceptance cap as the GCS payload; an oversized filter
+                // is ignored rather than failing the whole request.
+                if v.count <= maxAcceptBytes, let fid = String(data: v, encoding: .utf8) {
                     fragmentIdFilter = fid
                 }
             default:

bitchat/Noise/NoiseProtocol.swift

@@ -93,6 +93,7 @@ enum NoisePattern {
     case XX  // Most versatile, mutual authentication
     case IK  // Initiator knows responder's static key
     case NK  // Anonymous initiator
+    case X   // One-way: single message to a known static key (no response)
 }
 
 enum NoiseRole {
@@ -322,6 +323,13 @@ final class NoiseCipherState {
                 throw NoiseError.replayDetected
             }
             
+            // The 4-byte nonce prefix has been stripped, so the remaining bytes
+            // must still hold at least the 16-byte Poly1305 tag. The up-front
+            // `ciphertext.count >= 16` guard is not sufficient here (it counts
+            // the nonce), and `prefix(count - 16)` would trap on a short payload.
+            guard actualCiphertext.count >= 16 else {
+                throw NoiseError.invalidCiphertext
+            }
             // Split ciphertext and tag
             encryptedData = actualCiphertext.prefix(actualCiphertext.count - 16)
             tag = actualCiphertext.suffix(16)
@@ -594,7 +602,7 @@ final class NoiseHandshakeState {
         switch pattern {
         case .XX:
             break // No pre-message keys
-        case .IK, .NK:
+        case .IK, .NK, .X:
             if role == .initiator, let remoteStatic = remoteStaticPublic {
                 symmetricState.mixHash(remoteStatic.rawRepresentation)
             } else if role == .responder, let localStatic = localStaticPublic {
@@ -715,7 +723,7 @@ final class NoiseHandshakeState {
         return messageBuffer
     }
     
-    func readMessage(_ message: Data, expectedPayloadLength: Int = 0) throws -> Data {
+    func readMessage(_ message: Data, expectedPayloadLength _: Int = 0) throws -> Data {
         
         guard currentPattern < messagePatterns.count else {
             throw NoiseError.handshakeComplete
@@ -897,6 +905,7 @@ extension NoisePattern {
         case .XX: return "XX"
         case .IK: return "IK"
         case .NK: return "NK"
+        case .X: return "X"
         }
     }
     
@@ -918,6 +927,10 @@ extension NoisePattern {
                 [.e, .es],      // -> e, es
                 [.e, .ee]       // <- e, ee
             ]
+        case .X:
+            return [
+                [.e, .es, .s, .ss] // -> e, es, s, ss (single one-way message)
+            ]
         }
     }
 }

bitchat/Noise/NoiseSecurityConstants.swift

@@ -6,14 +6,60 @@
 // For more information, see <https://unlicense.org>
 //
 
+import BitFoundation
 import Foundation
 
 enum NoiseSecurityConstants {
     // Maximum message size to prevent memory exhaustion
     static let maxMessageSize = 65535 // 64KB as per Noise spec
+
+    /// The extracted transport nonce (4 bytes) and Poly1305 tag (16 bytes)
+    /// added by `NoiseCipherState` around every transport plaintext.
+    static let transportCiphertextOverhead = 20
+
+    /// Private files are an explicit BitChat extension to the ordinary Noise
+    /// message-size ceiling. They remain bounded by the same framed-file cap
+    /// used by the binary and fragment decoders. Only the `.privateFile`
+    /// typed-payload path is allowed to use this larger budget.
+    private static let privateFileOuterPacketOverhead =
+        (BinaryProtocol.v1HeaderSize + 2) // v2 adds two length bytes
+        + BinaryProtocol.senderIDSize
+        + BinaryProtocol.recipientIDSize
+    static let maxPrivateFilePlaintextSize = FileTransferLimits.maxFramedFileBytes
+        - privateFileOuterPacketOverhead
+        - transportCiphertextOverhead
+    static let maxPrivateFileCiphertextSize =
+        maxPrivateFilePlaintextSize + transportCiphertextOverhead
     
     // Maximum handshake message size
     static let maxHandshakeMessageSize = 2048 // 2KB to accommodate XX pattern
+
+    // Noise XX message 1 contains only the initiator's 32-byte ephemeral key.
+    static let xxInitialMessageSize = 32
+
+    // Bounds an ordinary initiator whose message 1 or 2 is lost.
+    static let ordinaryHandshakeTimeout: TimeInterval = 10
+
+    // Bounds the receive-only rollback quarantine created by an unauthenticated
+    // inbound message 1. A lost message 3 must not strand outbound traffic.
+    static let ordinaryResponderHandshakeTimeout: TimeInterval = 20
+
+    // A released client may immediately retry after both crossed initiators
+    // yielded. Give that unilateral retry a brief head start before the
+    // patched side spends its one bounded recovery.
+    static let handshakeCollisionRecoveryDelay: TimeInterval = 0.2
+
+    // Rate-limited recovery remains actionable without spinning.
+    static let handshakeRateLimitRecoveryDelay: TimeInterval = 60
+
+    // Covers only reordering between a winning message 3 and the losing
+    // crossed message 1.
+    static let recentInitiatorCompletionGracePeriod: TimeInterval = 1
+
+    // After unauthenticated responder rollback, reject another attempt long
+    // enough that paced message 1 traffic cannot keep outbound paused. A
+    // legitimate peer converges through the one manager-owned local retry.
+    static let ordinaryReconnectRollbackCooldown: TimeInterval = 60
     
     // Session timeout - sessions older than this should be renegotiated
     static let sessionTimeout: TimeInterval = 86400 // 24 hours
@@ -21,12 +67,6 @@ enum NoiseSecurityConstants {
     // 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

bitchat/Noise/NoiseSecurityError.swift

@@ -14,5 +14,4 @@ enum NoiseSecurityError: Error {
     case messageTooLarge
     case invalidPeerID
     case rateLimitExceeded
-    case handshakeTimeout
 }

bitchat/Noise/NoiseSecurityValidator.swift

@@ -14,6 +14,19 @@ struct NoiseSecurityValidator {
     static func validateMessageSize(_ data: Data) -> Bool {
         return data.count <= NoiseSecurityConstants.maxMessageSize
     }
+
+    static func validateCiphertextSize(_ data: Data) -> Bool {
+        data.count <= NoiseSecurityConstants.maxMessageSize
+            + NoiseSecurityConstants.transportCiphertextOverhead
+    }
+
+    static func validatePrivateFileMessageSize(_ data: Data) -> Bool {
+        data.count <= NoiseSecurityConstants.maxPrivateFilePlaintextSize
+    }
+
+    static func validatePrivateFileCiphertextSize(_ data: Data) -> Bool {
+        data.count <= NoiseSecurityConstants.maxPrivateFileCiphertextSize
+    }
     
     /// Validate handshake message size
     static func validateHandshakeMessageSize(_ data: Data) -> Bool {

bitchat/Noise/NoiseSession.swift

@@ -66,7 +66,10 @@ class NoiseSession {
             
             // Only initiator writes the first message
             if role == .initiator {
-                let message = try handshakeState!.writeMessage()
+                guard let handshake = handshakeState else {
+                    throw NoiseSessionError.invalidState
+                }
+                let message = try handshake.writeMessage()
                 sentHandshakeMessages.append(message)
                 return message
             } else {

bitchat/Noise/NoiseSessionError.swift

@@ -11,4 +11,11 @@ enum NoiseSessionError: Error, Equatable {
     case notEstablished
     case sessionNotFound
     case alreadyEstablished
+    case peerIdentityMismatch
+}
+
+/// The manager owns the exact attempt's one bounded recovery. Packet handling
+/// must not launch its historical second, immediate restart for this failure.
+struct NoiseManagedHandshakeFailure: Error {
+    let underlying: Error
 }

bitchat/Noise/SecureNoiseSession.swift

@@ -24,8 +24,12 @@ final class SecureNoiseSession: NoiseSession {
             throw NoiseSecurityError.sessionExhausted
         }
         
-        // Validate message size
-        guard NoiseSecurityValidator.validateMessageSize(plaintext) else {
+        // Ordinary Noise messages keep the protocol ceiling. Finalized media
+        // is the sole typed-payload extension and remains under the framed-file
+        // cap enforced again at the service and file-decoder layers.
+        let isPrivateFile = NoisePayloadType.isPrivateFile(rawValue: plaintext.first)
+            && NoiseSecurityValidator.validatePrivateFileMessageSize(plaintext)
+        guard NoiseSecurityValidator.validateMessageSize(plaintext) || isPrivateFile else {
             throw NoiseSecurityError.messageTooLarge
         }
         
@@ -42,8 +46,11 @@ final class SecureNoiseSession: NoiseSession {
             throw NoiseSecurityError.sessionExpired
         }
         
-        // Validate message size
-        guard NoiseSecurityValidator.validateMessageSize(ciphertext) else {
+        // The payload type is encrypted, so a large candidate can only be
+        // bounded here; `NoiseEncryptionService.decrypt` authenticates it and
+        // then requires the resulting type to be `.privateFile`.
+        guard NoiseSecurityValidator.validateCiphertextSize(ciphertext)
+                || NoiseSecurityValidator.validatePrivateFileCiphertextSize(ciphertext) else {
             throw NoiseSecurityError.messageTooLarge
         }
         

bitchat/Nostr/GeoRelayDirectory.swift

@@ -32,6 +32,23 @@ struct GeoRelayDirectoryDependencies {
     var retrySleep: (TimeInterval) async -> Void
     var activeNotificationName: Notification.Name?
     var autoStart: Bool
+    var validationPolicy: GeoRelayDirectoryValidationPolicy
+}
+
+struct GeoRelayDirectoryValidationPolicy: Sendable {
+    let maximumBytes: Int
+    let maximumRows: Int
+    let maximumEntries: Int
+    let minimumRemoteEntries: Int
+    let minimumRetainedFraction: Double
+
+    static let live = GeoRelayDirectoryValidationPolicy(
+        maximumBytes: 512 * 1024,
+        maximumRows: 5_000,
+        maximumEntries: 5_000,
+        minimumRemoteEntries: 50,
+        minimumRetainedFraction: 0.5
+    )
 }
 
 private extension GeoRelayDirectoryDependencies {
@@ -44,21 +61,57 @@ private extension GeoRelayDirectoryDependencies {
 #else
         let activeNotificationName: Notification.Name? = nil
 #endif
+        let validationPolicy = GeoRelayDirectoryValidationPolicy.live
 
         return Self(
             userDefaults: .standard,
             notificationCenter: .default,
             now: Date.init,
-            remoteURL: URL(string: "https://raw.githubusercontent.com/permissionlesstech/georelays/refs/heads/main/nostr_relays.csv")!,
+            // Runtime refreshes only from bitchat's reviewed copy. Upstream
+            // georelays/main is imported by a validator-backed pull request,
+            // so an upstream mutation cannot immediately retarget clients.
+            remoteURL: URL(string: "https://raw.githubusercontent.com/permissionlesstech/bitchat/refs/heads/main/relays/online_relays_gps.csv")!,
             fetchInterval: TransportConfig.geoRelayFetchIntervalSeconds,
             refreshCheckInterval: TransportConfig.geoRelayRefreshCheckIntervalSeconds,
             retryInitialSeconds: TransportConfig.geoRelayRetryInitialSeconds,
             retryMaxSeconds: TransportConfig.geoRelayRetryMaxSeconds,
-            awaitTorReady: { await TorManager.shared.awaitReady() },
+            // Only wait for Tor when Tor is switched on. With it off, the fetch
+            // is meant to go direct through the same unproxied session the relay
+            // sockets already use — and `TorManager` has been shut down, so
+            // awaiting readiness would spend the whole bootstrap timeout on
+            // every refresh and freeze the directory on its cached copy.
+            //
+            // Deliberately keyed on the preference rather than live readiness:
+            // if Tor is wanted but not ready, this must keep returning false so
+            // the fetch is skipped instead of silently leaking the IP.
+            awaitTorReady: {
+                guard NetworkActivationService.persistedTorPreference() else { return true }
+                return await TorManager.shared.awaitReady()
+            },
             makeFetchData: {
                 let session = TorURLSession.shared.session
                 return { request in
-                    let (data, _) = try await session.data(for: request)
+                    let (bytes, response) = try await session.bytes(for: request)
+                    guard let response = response as? HTTPURLResponse,
+                          (200...299).contains(response.statusCode),
+                          response.url == request.url else {
+                        throw URLError(.badServerResponse)
+                    }
+
+                    let maximumBytes = validationPolicy.maximumBytes
+                    guard response.expectedContentLength <= Int64(maximumBytes) else {
+                        throw URLError(.dataLengthExceedsMaximum)
+                    }
+                    var data = Data()
+                    if response.expectedContentLength > 0 {
+                        data.reserveCapacity(Int(response.expectedContentLength))
+                    }
+                    for try await byte in bytes {
+                        guard data.count < maximumBytes else {
+                            throw URLError(.dataLengthExceedsMaximum)
+                        }
+                        data.append(byte)
+                    }
                     return data
                 }
             },
@@ -76,7 +129,11 @@ private extension GeoRelayDirectoryDependencies {
                     )
                     let dir = base.appendingPathComponent("bitchat", isDirectory: true)
                     try? FileManager.default.createDirectory(at: dir, withIntermediateDirectories: true)
-                    return dir.appendingPathComponent("georelays_cache.csv")
+                    // v2 ignores caches populated from the old direct-upstream
+                    // trust path and subjects every load to strict validation.
+                    let legacyCache = dir.appendingPathComponent("georelays_cache.csv")
+                    try? FileManager.default.removeItem(at: legacyCache)
+                    return dir.appendingPathComponent("georelays_cache_v2.csv")
                 } catch {
                     return nil
                 }
@@ -94,7 +151,8 @@ private extension GeoRelayDirectoryDependencies {
                 try? await Task.sleep(nanoseconds: nanoseconds)
             },
             activeNotificationName: activeNotificationName,
-            autoStart: true
+            autoStart: true,
+            validationPolicy: validationPolicy
         )
     }
 }
@@ -125,7 +183,7 @@ final class GeoRelayDirectory {
     }
 
     private enum DetachedFetchOutcome: Sendable {
-        case success(entries: [Entry], csv: String)
+        case success(entries: [Entry], csv: Data)
         case torNotReady
         case invalidData
         case network(String)
@@ -212,6 +270,8 @@ final class GeoRelayDirectory {
         )
         let awaitTorReady = dependencies.awaitTorReady
         let fetchData = dependencies.makeFetchData()
+        let validationPolicy = dependencies.validationPolicy
+        let baselineEntries = Set(entries)
 
         Task { [weak self] in
             guard let self else { return }
@@ -219,7 +279,9 @@ final class GeoRelayDirectory {
             let outcome = await Self.fetchRemoteOutcome(
                 request: request,
                 awaitTorReady: awaitTorReady,
-                fetchData: fetchData
+                fetchData: fetchData,
+                validationPolicy: validationPolicy,
+                baselineEntries: baselineEntries
             )
 
             switch outcome {
@@ -238,7 +300,9 @@ final class GeoRelayDirectory {
     nonisolated private static func fetchRemoteOutcome(
         request: URLRequest,
         awaitTorReady: @escaping @Sendable () async -> Bool,
-        fetchData: @escaping @Sendable (URLRequest) async throws -> Data
+        fetchData: @escaping @Sendable (URLRequest) async throws -> Data,
+        validationPolicy: GeoRelayDirectoryValidationPolicy,
+        baselineEntries: Set<Entry>
     ) async -> DetachedFetchOutcome {
         await Task.detached(priority: .utility) {
             let ready = await awaitTorReady()
@@ -246,16 +310,16 @@ final class GeoRelayDirectory {
 
             do {
                 let data = try await fetchData(request)
-                guard let text = String(data: data, encoding: .utf8) else {
+                guard let parsed = Self.validatedEntries(
+                    from: data,
+                    policy: validationPolicy,
+                    minimumEntries: validationPolicy.minimumRemoteEntries,
+                    baselineEntries: baselineEntries
+                ) else {
                     return .invalidData
                 }
 
-                let parsed = Self.parseCSV(text)
-                guard !parsed.isEmpty else {
-                    return .invalidData
-                }
-
-                return .success(entries: parsed, csv: text)
+                return .success(entries: parsed, csv: data)
             } catch {
                 return .network(error.localizedDescription)
             }
@@ -269,7 +333,7 @@ final class GeoRelayDirectory {
     }
 
     @MainActor
-    private func handleFetchSuccess(entries parsed: [Entry], csv: String) {
+    private func handleFetchSuccess(entries parsed: [Entry], csv: Data) {
         entries = parsed
         persistCache(csv)
         dependencies.userDefaults.set(dependencies.now(), forKey: lastFetchKey)
@@ -321,9 +385,8 @@ final class GeoRelayDirectory {
         cleanupState.retryTask = nil
     }
 
-    private func persistCache(_ text: String) {
+    private func persistCache(_ data: Data) {
         guard let url = dependencies.cacheURL() else { return }
-        guard let data = text.data(using: .utf8) else { return }
         do {
             try dependencies.writeData(data, url)
         } catch {
@@ -336,9 +399,12 @@ final class GeoRelayDirectory {
         // Prefer cached file if present
         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 }
+           let entries = Self.validatedEntries(
+               from: data,
+               policy: dependencies.validationPolicy,
+               minimumEntries: 1
+           ) {
+            return entries
         }
 
         // Try bundled resource(s)
@@ -346,36 +412,157 @@ final class GeoRelayDirectory {
 
         for url in bundleCandidates {
             if let data = dependencies.readData(url),
-               let text = String(data: data, encoding: .utf8) {
-                let arr = Self.parseCSV(text)
-                if !arr.isEmpty { return arr }
+               let entries = Self.validatedEntries(
+                   from: data,
+                   policy: dependencies.validationPolicy,
+                   minimumEntries: 1
+               ) {
+                return entries
             }
         }
 
         // Try filesystem path (development/test)
         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)
+           let entries = Self.validatedEntries(
+               from: data,
+               policy: dependencies.validationPolicy,
+               minimumEntries: 1
+           ) {
+            return entries
         }
 
         SecureLogger.warning("GeoRelayDirectory: no local CSV found; entries empty", category: .session)
         return []
     }
 
-    nonisolated static func parseCSV(_ text: String) -> [Entry] {
-        var result: Set<Entry> = []
-        let lines = text.split(whereSeparator: { $0.isNewline })
-        for (idx, raw) in lines.enumerated() {
-            guard let line = raw.trimmedOrNilIfEmpty else { continue }
-            if idx == 0 && line.lowercased().contains("relay url") { continue }
-            let parts = line.split(separator: ",").map { $0.trimmed }
-            guard parts.count >= 3 else { continue }
-            guard let host = NostrRelayURL.directoryAddress(parts[0]) else { continue }
-            guard let lat = Double(parts[1]), let lon = Double(parts[2]) else { continue }
-            result.insert(Entry(host: host, lat: lat, lon: lon))
+    /// Parses the fixed three-column format as an all-or-nothing trust unit.
+    /// One malformed or conflicting row rejects the complete dataset rather
+    /// than silently shrinking or partially replacing the current directory.
+    nonisolated static func validatedEntries(
+        from data: Data,
+        policy: GeoRelayDirectoryValidationPolicy,
+        minimumEntries: Int,
+        baselineEntries: Set<Entry>? = nil
+    ) -> [Entry]? {
+        guard !data.isEmpty, data.count <= policy.maximumBytes,
+              let text = String(data: data, encoding: .utf8),
+              !text.hasPrefix("\u{feff}") else {
+            return nil
         }
-        return Array(result)
+
+        let lines = text.split(whereSeparator: { $0.isNewline })
+            .map { $0.trimmingCharacters(in: .whitespacesAndNewlines) }
+            .filter { !$0.isEmpty }
+        guard let header = lines.first,
+              lines.count - 1 <= policy.maximumRows else {
+            return nil
+        }
+
+        let headerParts = header
+            .split(separator: ",", omittingEmptySubsequences: false)
+            .map { $0.trimmingCharacters(in: .whitespacesAndNewlines).lowercased() }
+        let supportedHeaders = [
+            ["relay url", "latitude", "longitude"],
+            ["relay url", "lat", "lon"]
+        ]
+        guard supportedHeaders.contains(headerParts) else {
+            return nil
+        }
+
+        var entriesByHost: [String: Entry] = [:]
+        for line in lines.dropFirst() {
+            let parts = line
+                .split(separator: ",", omittingEmptySubsequences: false)
+                .map { $0.trimmingCharacters(in: .whitespacesAndNewlines) }
+            guard parts.count == 3,
+                  let host = validatedDirectoryAddress(parts[0]),
+                  let latitude = Double(parts[1]), latitude.isFinite,
+                  (-90.0...90.0).contains(latitude),
+                  let longitude = Double(parts[2]), longitude.isFinite,
+                  (-180.0...180.0).contains(longitude) else {
+                return nil
+            }
+
+            let entry = Entry(host: host, lat: latitude, lon: longitude)
+            if let existing = entriesByHost[host], existing != entry {
+                // One endpoint cannot truthfully occupy two coordinates. Do
+                // not let row ordering choose which location clients trust.
+                return nil
+            }
+            entriesByHost[host] = entry
+            guard entriesByHost.count <= policy.maximumEntries else { return nil }
+        }
+
+        let parsedEntries = Set(entriesByHost.values)
+        guard parsedEntries.count >= minimumEntries else { return nil }
+
+        if let baselineEntries {
+            guard (0...1).contains(policy.minimumRetainedFraction) else { return nil }
+            let requiredOverlap = Int(
+                ceil(Double(baselineEntries.count) * policy.minimumRetainedFraction)
+            )
+            guard parsedEntries.intersection(baselineEntries).count >= requiredOverlap else {
+                return nil
+            }
+        }
+
+        return parsedEntries.sorted {
+            ($0.host, $0.lat, $0.lon) < ($1.host, $1.lat, $1.lon)
+        }
+    }
+
+    nonisolated private static func validatedDirectoryAddress(_ rawValue: String) -> String? {
+        let value = rawValue.trimmingCharacters(in: .whitespacesAndNewlines)
+        guard !value.isEmpty,
+              value.unicodeScalars.allSatisfy({
+                  $0.isASCII && !CharacterSet.controlCharacters.contains($0)
+              }) else {
+            return nil
+        }
+
+        let candidate = value.contains("://") ? value : "wss://\(value)"
+        guard let components = URLComponents(string: candidate),
+              let scheme = components.scheme?.lowercased(),
+              scheme == "wss" || scheme == "https",
+              components.user == nil,
+              components.password == nil,
+              components.query == nil,
+              components.fragment == nil,
+              components.path.isEmpty || components.path == "/",
+              let rawHost = components.host else {
+            return nil
+        }
+
+        let host = rawHost.lowercased()
+        guard !host.isEmpty, host.count <= 253,
+              host.unicodeScalars.allSatisfy({ $0.isASCII }),
+              !host.hasSuffix("."),
+              host != "localhost",
+              !host.hasSuffix(".localhost"),
+              !host.hasSuffix(".local"),
+              !host.hasSuffix(".internal") else {
+            return nil
+        }
+
+        let labels = host.split(separator: ".", omittingEmptySubsequences: false)
+        let allowed = CharacterSet(charactersIn: "abcdefghijklmnopqrstuvwxyz0123456789-")
+        guard labels.count >= 2,
+              !labels.allSatisfy({ $0.allSatisfy(\.isNumber) }),
+              labels.allSatisfy({ label in
+                  (1...63).contains(label.count) &&
+                  label.first != "-" &&
+                  label.last != "-" &&
+                  label.unicodeScalars.allSatisfy { allowed.contains($0) }
+              }) else {
+            return nil
+        }
+
+        if let port = components.port {
+            guard (1...65_535).contains(port) else { return nil }
+            if port != 443 { return "\(host):\(port)" }
+        }
+        return host
     }
 
     // MARK: - Observers & Timers

bitchat/Nostr/NostrIdentity.swift

@@ -1,19 +1,18 @@
 import Foundation
 import P256K
 
-/// Manages Nostr identity (secp256k1 keypair) for NIP-17 private messaging
+/// Manages the secp256k1 identity used by BitChat's Nostr relay features,
+/// including the proprietary private-envelope transport.
 struct NostrIdentity: Codable {
     let privateKey: Data
     let publicKey: Data
     let npub: String // Bech32-encoded public key
-    let createdAt: Date
-    
+
     /// Memberwise initializer
-    init(privateKey: Data, publicKey: Data, npub: String, createdAt: Date) {
+    init(privateKey: Data, publicKey: Data, npub: String, createdAt _: Date) {
         self.privateKey = privateKey
         self.publicKey = publicKey
         self.npub = npub
-        self.createdAt = createdAt
     }
     
     /// Generate a new Nostr identity
@@ -39,12 +38,6 @@ struct NostrIdentity: Codable {
         self.privateKey = privateKeyData
         self.publicKey = xOnlyPubkey
         self.npub = try Bech32.encode(hrp: "npub", data: xOnlyPubkey)
-        self.createdAt = Date()
-    }
-    
-    /// Get signing key for event signatures
-    func signingKey() throws -> P256K.Signing.PrivateKey {
-        try P256K.Signing.PrivateKey(dataRepresentation: privateKey)
     }
     
     /// Get Schnorr signing key for Nostr event signatures

bitchat/Nostr/NostrIdentityBridge.swift

@@ -15,7 +15,7 @@ final class NostrIdentityBridge {
 
     private let keychain: KeychainManagerProtocol
 
-    init(keychain: KeychainManagerProtocol = KeychainManager()) {
+    init(keychain: KeychainManagerProtocol = KeychainManager.makeDefault()) {
         self.keychain = keychain
     }
     
@@ -37,14 +37,6 @@ final class NostrIdentityBridge {
         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())"
@@ -57,31 +49,19 @@ final class NostrIdentityBridge {
     
     /// 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
-        }
+        // Must go through the injected keychain, not raw SecItem calls:
+        // under test that keychain is in-memory, and a direct delete here
+        // would wipe the developer's real Nostr identity on every test run.
+        keychain.deleteAll(service: keychainService)
 
         deviceSeedCache = nil
+        // Also drop the in-memory derived per-geohash identities. These hold the
+        // actual secp256k1 private keys; if left cached, post-panic geohash
+        // messages would still be signed with pre-panic keys (linkable across the
+        // wipe) until the app is force-quit.
+        cacheLock.lock()
+        derivedIdentityCache.removeAll()
+        cacheLock.unlock()
     }
 
     // MARK: - Per-Geohash Identities (Location Channels)
@@ -96,16 +76,22 @@ final class NostrIdentityBridge {
             deviceSeedCache = existing
             return existing
         }
-        var seed = Data(count: 32)
-        _ = seed.withUnsafeMutableBytes { ptr in
-            SecRandomCopyBytes(kSecRandomDefault, 32, ptr.baseAddress!)
-        }
+        // CryptoKit key generation cannot fail, unlike SecRandomCopyBytes —
+        // a discarded failure here would persist an all-zero identity seed.
+        let seed = SymmetricKey(size: .bits256).withUnsafeBytes { Data($0) }
         // 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 mesh-bridge
+    /// rendezvous cell. Distinct HMAC label keeps it unlinkable from the
+    /// geohash-chat identity for the same cell string.
+    func deriveIdentity(forBridgeRendezvous cell: String) throws -> NostrIdentity {
+        try deriveIdentity(forGeohash: "bridge|" + cell)
+    }
+
     /// 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.

bitchat/Nostr/NostrPoW.swift

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

bitchat/Nostr/NostrProtocol.swift

@@ -7,70 +7,114 @@ import Security
 // Note: This file depends on Data extension from BinaryEncodingUtils.swift
 // Make sure BinaryEncodingUtils.swift is included in the target
 
-/// NIP-17 Protocol Implementation for Private Direct Messages
+/// BitChat's private-envelope protocol transported over Nostr relays.
+///
+/// This construction is deliberately BitChat-specific and is **not** NIP-17,
+/// NIP-44, or NIP-59 compatible, even though it historically reuses those
+/// NIPs' kind numbers (1059/13/14) and a `v2:` content prefix. It uses Nostr
+/// events and secp256k1 identities, but the XChaCha20-Poly1305 payload layout
+/// and key derivation are proprietary and interoperate only with BitChat
+/// clients.
 struct NostrProtocol {
-    
+
     /// Nostr event kinds
     enum EventKind: Int {
         case metadata = 0
         case textNote = 1
-        case dm = 14 // NIP-17 DM rumor kind
-        case seal = 13 // NIP-17 sealed event
-        case giftWrap = 1059 // NIP-59 gift wrap
+        // BitChat's proprietary private-envelope layers. These reuse the
+        // NIP-17/NIP-59 kind numbers (14/13/1059) for historical reasons, but
+        // the encrypted payloads are BitChat-specific and not NIP-compatible.
+        case dm = 14 // unsigned inner message (inside ciphertext)
+        case seal = 13 // sender-signed seal (inside ciphertext)
+        case giftWrap = 1059 // public outer envelope (one-time key)
         case ephemeralEvent = 20000
         case geohashPresence = 20001
+        case deletion = 5 // NIP-09 event deletion request
+        /// Sealed courier envelope parked on relays under its rotating
+        /// recipient tag (`#x`). Regular (stored) kind so it survives until
+        /// its NIP-40 expiration — the whole point is store-and-forward.
+        case courierDrop = 1401
     }
-    
-    /// Create a NIP-17 private message
+
+    /// Bound work before Base64-decoding either encrypted layer of an inbound
+    /// private envelope, and before parsing each decrypted nested JSON layer.
+    /// Real envelopes are normally a few KiB; 64 KiB leaves ample headroom
+    /// without letting an addressed relay event drive unbounded allocation.
+    static let maximumPrivateEnvelopeCiphertextBytes = 64 * 1024
+
+    /// Create a BitChat private envelope for relay transport (outer kind 1059).
     static func createPrivateMessage(
         content: String,
         recipientPubkey: String,
         senderIdentity: NostrIdentity
     ) throws -> NostrEvent {
-        
-        // Creating private message
-        
-        // 1. Create the rumor (unsigned event)
+        try createPrivateMessage(
+            content: content,
+            recipientPubkey: recipientPubkey,
+            senderIdentity: senderIdentity,
+            messageTags: []
+        )
+    }
+
+    private static func createPrivateMessage(
+        content: String,
+        recipientPubkey: String,
+        senderIdentity: NostrIdentity,
+        messageTags: [[String]]
+    ) throws -> NostrEvent {
+        // 1. Create the rumor (unsigned inner event)
         let rumor = NostrEvent(
             pubkey: senderIdentity.publicKeyHex,
             createdAt: Date(),
-            kind: .dm, // NIP-17: DM rumor kind 14
-            tags: [],
+            kind: .dm,
+            tags: messageTags,
             content: content
         )
-        
-        // 2. Create ephemeral key for this message
-        let ephemeralKey = try P256K.Schnorr.PrivateKey()
-        // Created ephemeral key for seal
-        
-        // 3. Seal the rumor (encrypt to recipient)
+
+        // 2. Seal the rumor (encrypt to recipient) and sign it with the SENDER'S
+        //    real identity key so the recipient can authenticate who sent the
+        //    message; signing with a throwaway key leaves DMs
+        //    forgeable/impersonatable.
+        let senderKey = try senderIdentity.schnorrSigningKey()
         let sealedEvent = try createSeal(
             rumor: rumor,
             recipientPubkey: recipientPubkey,
-            senderKey: ephemeralKey
+            senderKey: senderKey
         )
-        
-        // 4. Gift wrap the sealed event (encrypt to recipient again)
+
+        // 3. Wrap the sealed event with a throwaway ephemeral key (the wrap
+        //    layer hides the sender's identity from relays; createGiftWrap mints
+        //    its own ephemeral key internally).
         let giftWrap = try createGiftWrap(
             seal: sealedEvent,
-            recipientPubkey: recipientPubkey,
-            senderKey: ephemeralKey
+            recipientPubkey: recipientPubkey
         )
-        
-        // Created gift wrap
-        
+
         return giftWrap
     }
-    
-    /// Decrypt a received NIP-17 message
-    /// Returns the content, sender pubkey, and the actual message timestamp (not the randomized gift wrap timestamp)
+
+    /// Decrypt a received BitChat private envelope.
+    /// Returns the content, sender pubkey, and the actual message timestamp (not the randomized outer timestamp)
     static func decryptPrivateMessage(
         giftWrap: NostrEvent,
         recipientIdentity: NostrIdentity
     ) throws -> (content: String, senderPubkey: String, timestamp: Int) {
-        
-        // Starting decryption
-        
+
+        // 0. Validate the untrusted outer envelope before any decryption work.
+        //    Every BitChat client (released iOS and current Android) publishes
+        //    exactly one outer recipient `p` tag on a validly signed kind-1059
+        //    wrap; anything else is malformed or misbound.
+        guard giftWrap.content.utf8.count <= maximumPrivateEnvelopeCiphertextBytes else {
+            SecureLogger.error("❌ Rejecting DM: oversized outer envelope ciphertext", category: .session)
+            throw NostrError.invalidCiphertext
+        }
+        guard giftWrap.kind == EventKind.giftWrap.rawValue,
+              giftWrap.tags == [["p", recipientIdentity.publicKeyHex]],
+              giftWrap.isValidSignature() else {
+            SecureLogger.error("❌ Rejecting DM: malformed or misbound outer envelope", category: .session)
+            throw NostrError.invalidEvent
+        }
+
         // 1. Unwrap the gift wrap
         let seal: NostrEvent
         do {
@@ -84,7 +128,18 @@ struct NostrProtocol {
             throw error
         }
         
-        // 2. Open the seal
+        // 2. Authenticate the seal. The seal MUST be signed by the sender's real
+        //    identity key; without this check a DM is forgeable by anyone who
+        //    knows the recipient's npub. Every BitChat sender emits a tagless
+        //    kind-13 seal, so bind the decrypted layer to that exact shape.
+        guard seal.kind == EventKind.seal.rawValue,
+              seal.tags.isEmpty,
+              seal.isValidSignature() else {
+            SecureLogger.error("❌ Rejecting DM: seal is malformed or its signature is missing/invalid", category: .session)
+            throw NostrError.invalidEvent
+        }
+
+        // 3. Open the seal
         let rumor: NostrEvent
         do {
             rumor = try openSeal(
@@ -96,10 +151,96 @@ struct NostrProtocol {
             SecureLogger.error("❌ Failed to open seal: \(error)", category: .session)
             throw error
         }
-        
-        return (content: rumor.content, senderPubkey: rumor.pubkey, timestamp: rumor.created_at)
+
+        // 4. The rumor is intentionally unsigned; sender authentication comes
+        //    from the seal. The sender claimed inside the rumor must match the
+        //    key that actually signed the seal, otherwise the sender field is
+        //    unauthenticated and spoofable. Also bind the inner kind and tag
+        //    shape to what BitChat clients actually emit.
+        guard rumor.kind == EventKind.dm.rawValue,
+              validInnerMessageTags(rumor.tags, recipientPubkey: recipientIdentity.publicKeyHex),
+              rumor.sig == nil,
+              seal.pubkey == rumor.pubkey else {
+            SecureLogger.error("❌ Rejecting DM: rumor is malformed or does not match seal signer", category: .session)
+            throw NostrError.invalidEvent
+        }
+
+        // Return the seal signer's pubkey as the authenticated sender.
+        return (content: rumor.content, senderPubkey: seal.pubkey, timestamp: rumor.created_at)
     }
 
+    /// Released iOS envelopes use no inner tags, while current Android
+    /// envelopes place exactly the authenticated recipient's `p` tag on the
+    /// unsigned inner event. Accept only those two historical shapes;
+    /// alternate recipients, duplicate tags, and extra tags are rejected.
+    private static func validInnerMessageTags(
+        _ tags: [[String]],
+        recipientPubkey: String
+    ) -> Bool {
+        tags.isEmpty || tags == [["p", recipientPubkey]]
+    }
+
+    #if DEBUG
+    static func createPrivateMessageWithInvalidSealSignatureForTesting(
+        content: String,
+        recipientPubkey: String,
+        senderIdentity: NostrIdentity
+    ) throws -> NostrEvent {
+        let rumor = NostrEvent(
+            pubkey: senderIdentity.publicKeyHex,
+            createdAt: Date(),
+            kind: .dm,
+            tags: [],
+            content: content
+        )
+        var seal = try createSeal(
+            rumor: rumor,
+            recipientPubkey: recipientPubkey,
+            senderKey: senderIdentity.schnorrSigningKey()
+        )
+        seal.sig = String(repeating: "0", count: 128)
+        return try createGiftWrap(seal: seal, recipientPubkey: recipientPubkey)
+    }
+
+    static func createPrivateMessageWithMismatchedSealRumorPubkeyForTesting(
+        content: String,
+        recipientPubkey: String,
+        rumorIdentity: NostrIdentity,
+        sealSignerIdentity: NostrIdentity
+    ) throws -> NostrEvent {
+        let rumor = NostrEvent(
+            pubkey: rumorIdentity.publicKeyHex,
+            createdAt: Date(),
+            kind: .dm,
+            tags: [],
+            content: content
+        )
+        let seal = try createSeal(
+            rumor: rumor,
+            recipientPubkey: recipientPubkey,
+            senderKey: sealSignerIdentity.schnorrSigningKey()
+        )
+        return try createGiftWrap(seal: seal, recipientPubkey: recipientPubkey)
+    }
+
+    /// Reproduces historical wire shapes (current Android places exactly one
+    /// recipient `p` tag on the unsigned inner event) without making the
+    /// production encoder depend on that quirk.
+    static func createPrivateMessageWithInnerTagsForTesting(
+        content: String,
+        recipientPubkey: String,
+        senderIdentity: NostrIdentity,
+        innerMessageTags: [[String]]
+    ) throws -> NostrEvent {
+        try createPrivateMessage(
+            content: content,
+            recipientPubkey: recipientPubkey,
+            senderIdentity: senderIdentity,
+            messageTags: innerMessageTags
+        )
+    }
+    #endif
+
     /// Create a geohash-scoped ephemeral public message (kind 20000)
     static func createEphemeralGeohashEvent(
         content: String,
@@ -108,6 +249,63 @@ struct NostrProtocol {
         nickname: String? = nil,
         teleported: Bool = false
     ) throws -> NostrEvent {
+        let event = NostrEvent(
+            pubkey: senderIdentity.publicKeyHex,
+            createdAt: Date(),
+            kind: .ephemeralEvent,
+            tags: ephemeralGeohashTags(geohash: geohash, nickname: nickname, teleported: teleported),
+            content: content
+        )
+        let schnorrKey = try senderIdentity.schnorrSigningKey()
+        return try event.sign(with: schnorrKey)
+    }
+
+    /// Create a kind-20000 geohash message carrying a NIP-13 proof-of-work
+    /// nonce tag (see `NostrPoW`). Mining runs off the calling actor and is
+    /// bounded by `NostrPoW.miningTimeCap`; when the cap hits (or the
+    /// surrounding task is cancelled) the event ships at the highest
+    /// committed difficulty still met, and if mining is impossible it ships
+    /// unmined — sending is never blocked.
+    static func createMinedEphemeralGeohashEvent(
+        content: String,
+        geohash: String,
+        senderIdentity: NostrIdentity,
+        nickname: String? = nil,
+        teleported: Bool = false,
+        powTargetBits: Int = NostrPoW.targetBits
+    ) async throws -> NostrEvent {
+        var tags = ephemeralGeohashTags(geohash: geohash, nickname: nickname, teleported: teleported)
+        // Fix created_at up front: the mined nonce commits to the full
+        // serialized event, so the signed event must reuse the exact value.
+        let createdAt = Int(Date().timeIntervalSince1970)
+        if let nonceTag = await NostrPoW.mineNonceTag(
+            pubkey: senderIdentity.publicKeyHex,
+            createdAt: createdAt,
+            kind: EventKind.ephemeralEvent.rawValue,
+            tags: tags,
+            content: content,
+            targetBits: powTargetBits
+        ) {
+            tags.append(nonceTag)
+        }
+        let event = NostrEvent(
+            pubkey: senderIdentity.publicKeyHex,
+            createdAt: Date(timeIntervalSince1970: TimeInterval(createdAt)),
+            kind: .ephemeralEvent,
+            tags: tags,
+            content: content
+        )
+        let schnorrKey = try senderIdentity.schnorrSigningKey()
+        return try event.sign(with: schnorrKey)
+    }
+
+    /// Tags for a kind-20000 geohash message (shared by the plain and mined
+    /// variants).
+    private static func ephemeralGeohashTags(
+        geohash: String,
+        nickname: String?,
+        teleported: Bool
+    ) -> [[String]] {
         var tags = [["g", geohash]]
         if let nickname = nickname?.trimmedOrNilIfEmpty {
             tags.append(["n", nickname])
@@ -115,15 +313,7 @@ struct NostrProtocol {
         if teleported {
             tags.append(["t", "teleport"])
         }
-        let event = NostrEvent(
-            pubkey: senderIdentity.publicKeyHex,
-            createdAt: Date(),
-            kind: .ephemeralEvent,
-            tags: tags,
-            content: content
-        )
-        let schnorrKey = try senderIdentity.schnorrSigningKey()
-        return try event.sign(with: schnorrKey)
+        return tags
     }
 
     /// Create a geohash presence heartbeat (kind 20001)
@@ -144,17 +334,115 @@ struct NostrProtocol {
         return try event.sign(with: schnorrKey)
     }
 
+    // MARK: - Mesh bridge (rendezvous) events
+
+    /// Create a mesh-bridge public message (kind 20000) for a geohash-cell
+    /// rendezvous. The distinct `r` tag keeps bridge traffic out of geohash
+    /// channel subscriptions (which filter on `#g`); `m` is
+    /// `[stable ID, mesh sender ID, wire timestamp in ms]`. Element 1 is the
+    /// content-stable mesh message ID (`MeshMessageIdentity`) for v1.7.0
+    /// parsers, which key their dedup on `m[1]` unconditionally and need it
+    /// per-message-unique. Current parsers key bridge rows by the authenticated
+    /// event ID and recompute elements 2-3 only as a radio-copy hint; the mesh
+    /// coordinates are public and cannot authenticate the Nostr signer.
+    static func createBridgeMeshEvent(
+        content: String,
+        cell: String,
+        senderIdentity: NostrIdentity,
+        nickname: String? = nil,
+        meshSenderID: String? = nil,
+        meshTimestampMs: UInt64? = nil
+    ) throws -> NostrEvent {
+        var tags = [["r", cell]]
+        if let nickname = nickname?.trimmedOrNilIfEmpty {
+            tags.append(["n", nickname])
+        }
+        if let meshSenderID = meshSenderID?.trimmedOrNilIfEmpty, let meshTimestampMs {
+            let stableID = MeshMessageIdentity.stableID(
+                senderIDHex: meshSenderID,
+                timestampMs: meshTimestampMs,
+                content: content
+            )
+            tags.append(["m", stableID, meshSenderID, String(meshTimestampMs)])
+        }
+        let event = NostrEvent(
+            pubkey: senderIdentity.publicKeyHex,
+            createdAt: Date(),
+            kind: .ephemeralEvent,
+            tags: tags,
+            content: content
+        )
+        let schnorrKey = try senderIdentity.schnorrSigningKey()
+        return try event.sign(with: schnorrKey)
+    }
+
+    /// Create a mesh-bridge presence heartbeat (kind 20001) on a rendezvous
+    /// cell: empty content, `r` tag only — the bridge analogue of geohash
+    /// presence, counted into "people across the bridge".
+    static func createBridgePresenceEvent(
+        cell: String,
+        senderIdentity: NostrIdentity
+    ) throws -> NostrEvent {
+        let event = NostrEvent(
+            pubkey: senderIdentity.publicKeyHex,
+            createdAt: Date(),
+            kind: .geohashPresence,
+            tags: [["r", cell]],
+            content: ""
+        )
+        let schnorrKey = try senderIdentity.schnorrSigningKey()
+        return try event.sign(with: schnorrKey)
+    }
+
+    /// Create a courier drop (kind 1401): an opaque sealed courier envelope
+    /// parked on relays. `x` is the hex recipient tag the recipient (or a
+    /// gateway acting for them) subscribes for; the NIP-40 expiration tracks
+    /// the envelope expiry so honoring relays garbage-collect the drop. The
+    /// signing identity should be a throwaway — the envelope authenticates
+    /// its sender internally via Noise-X, and linking drops to a stable
+    /// publisher key would leak courier traffic patterns.
+    static func createCourierDropEvent(
+        envelope: Data,
+        recipientTagHex: String,
+        expiresAt: Date,
+        senderIdentity: NostrIdentity
+    ) throws -> NostrEvent {
+        let tags = [
+            ["x", recipientTagHex],
+            ["expiration", String(Int(expiresAt.timeIntervalSince1970))]
+        ]
+        let event = NostrEvent(
+            pubkey: senderIdentity.publicKeyHex,
+            createdAt: Date(),
+            kind: .courierDrop,
+            tags: tags,
+            content: envelope.base64EncodedString()
+        )
+        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.
+    /// An optional `expiresAt` adds a NIP-40 expiration tag so honoring relays
+    /// drop the note in step with a bridged board post's expiry.
     static func createGeohashTextNote(
         content: String,
         geohash: String,
         senderIdentity: NostrIdentity,
-        nickname: String? = nil
+        nickname: String? = nil,
+        expiresAt: Date? = nil,
+        urgent: Bool = false
     ) throws -> NostrEvent {
         var tags = [["g", geohash]]
         if let nickname = nickname?.trimmedOrNilIfEmpty {
             tags.append(["n", nickname])
         }
+        if let expiresAt {
+            tags.append(["expiration", String(Int(expiresAt.timeIntervalSince1970))])
+        }
+        if urgent {
+            tags.append(["t", "urgent"])
+        }
         let event = NostrEvent(
             pubkey: senderIdentity.publicKeyHex,
             createdAt: Date(),
@@ -165,7 +453,25 @@ struct NostrProtocol {
         let schnorrKey = try senderIdentity.schnorrSigningKey()
         return try event.sign(with: schnorrKey)
     }
-    
+
+    /// Create a NIP-09 deletion request for one of our own events. Relays that
+    /// honor NIP-09 drop the referenced event; it must be signed by the same
+    /// key that signed the original.
+    static func createDeleteEvent(
+        ofEventID eventID: String,
+        senderIdentity: NostrIdentity
+    ) throws -> NostrEvent {
+        let event = NostrEvent(
+            pubkey: senderIdentity.publicKeyHex,
+            createdAt: Date(),
+            kind: .deletion,
+            tags: [["e", eventID]],
+            content: ""
+        )
+        let schnorrKey = try senderIdentity.schnorrSigningKey()
+        return try event.sign(with: schnorrKey)
+    }
+
     // MARK: - Private Methods
     
     private static func createSeal(
@@ -195,10 +501,9 @@ struct NostrProtocol {
     
     private static func createGiftWrap(
         seal: NostrEvent,
-        recipientPubkey: String,
-        senderKey: P256K.Schnorr.PrivateKey  // This is the ephemeral key used for the seal
+        recipientPubkey: String
     ) throws -> NostrEvent {
-        
+
         let sealJSON = try seal.jsonString()
         
         // Create new ephemeral key for gift wrap
@@ -237,14 +542,19 @@ struct NostrProtocol {
             recipientKey: recipientKey
         )
         
+        // Check UTF-8 size before allocating Data or invoking the general
+        // JSON parser on attacker-influenced plaintext.
+        guard decrypted.utf8.count <= maximumPrivateEnvelopeCiphertextBytes else {
+            throw NostrError.invalidCiphertext
+        }
         guard let data = decrypted.data(using: .utf8),
               let sealDict = try JSONSerialization.jsonObject(with: data) as? [String: Any] else {
             throw NostrError.invalidEvent
         }
-        
+
         let seal = try NostrEvent(from: sealDict)
         // Unwrapped seal
-        
+
         return seal
     }
     
@@ -259,16 +569,23 @@ struct NostrProtocol {
             recipientKey: recipientKey
         )
         
+        guard decrypted.utf8.count <= maximumPrivateEnvelopeCiphertextBytes else {
+            throw NostrError.invalidCiphertext
+        }
         guard let data = decrypted.data(using: .utf8),
               let rumorDict = try JSONSerialization.jsonObject(with: data) as? [String: Any] else {
             throw NostrError.invalidEvent
         }
-        
+
         return try NostrEvent(from: rumorDict)
     }
-    
-    // MARK: - Encryption (NIP-44 v2)
-    
+
+    // MARK: - BitChat private-envelope encryption
+    //
+    // Not NIP-44: the `v2:` prefix, base64url(nonce24 || ciphertext || tag)
+    // layout, XChaCha20-Poly1305 cipher, and HKDF parameters are all
+    // BitChat-specific.
+
     private static func encrypt(
         plaintext: String,
         recipientPubkey: String,
@@ -279,22 +596,25 @@ struct NostrProtocol {
             throw NostrError.invalidPublicKey
         }
         
-        // Encrypting message (NIP-44 v2: XChaCha20-Poly1305, versioned)
-        
         // Derive shared secret
         let sharedSecret = try deriveSharedSecret(
             privateKey: senderKey,
             publicKey: recipientPubkeyData
         )
-        // Derive NIP-44 v2 symmetric key (HKDF-SHA256 with label in info)
-        let key = try deriveNIP44V2Key(from: sharedSecret)
-        
+        // Derive the BitChat private-envelope symmetric key (HKDF-SHA256)
+        let key = try derivePrivateEnvelopeKey(from: sharedSecret)
+
         // 24-byte random nonce for XChaCha20-Poly1305
         var nonce24 = Data(count: 24)
-        _ = nonce24.withUnsafeMutableBytes { ptr in
+        let randomStatus = nonce24.withUnsafeMutableBytes { ptr in
             SecRandomCopyBytes(kSecRandomDefault, 24, ptr.baseAddress!)
         }
-        
+        // Never encrypt with an unrandomized nonce: nonce reuse under the same
+        // key breaks XChaCha20-Poly1305 confidentiality and authenticity.
+        guard randomStatus == errSecSuccess else {
+            throw NostrError.cryptographicFailure
+        }
+
         let pt = Data(plaintext.utf8)
         let sealed = try XChaCha20Poly1305Compat.seal(plaintext: pt, key: key, nonce24: nonce24)
         
@@ -311,8 +631,12 @@ struct NostrProtocol {
         senderPubkey: String,
         recipientKey: P256K.Schnorr.PrivateKey
     ) throws -> String {
-        // Expect NIP-44 v2 format
-        guard ciphertext.hasPrefix("v2:") else { throw NostrError.invalidCiphertext }
+        // Expect BitChat's historical `v2:` private-envelope framing, and
+        // bound work before Base64 decoding attacker-sized input.
+        guard ciphertext.utf8.count <= maximumPrivateEnvelopeCiphertextBytes,
+              ciphertext.hasPrefix("v2:") else {
+            throw NostrError.invalidCiphertext
+        }
         let encoded = String(ciphertext.dropFirst(3))
         guard let data = Base64URLCoding.decode(encoded),
               data.count > (24 + 16),
@@ -328,7 +652,7 @@ struct NostrProtocol {
         // Try decryption with even-Y then odd-Y when sender pubkey is x-only
         func attemptDecrypt(using pubKeyData: Data) throws -> Data {
             let ss = try deriveSharedSecret(privateKey: recipientKey, publicKey: pubKeyData)
-            let key = try deriveNIP44V2Key(from: ss)
+            let key = try derivePrivateEnvelopeKey(from: ss)
             return try XChaCha20Poly1305Compat.open(
                 ciphertext: Data(ct),
                 tag: Data(tag),
@@ -338,18 +662,25 @@ struct NostrProtocol {
         }
 
         // If 32 bytes (x-only) try both parities, otherwise single try
+        let plaintext: Data
         if senderPubkeyData.count == 32 {
             let even = Data([0x02]) + senderPubkeyData
             if let pt = try? attemptDecrypt(using: even) {
-                return String(data: pt, encoding: .utf8) ?? ""
+                plaintext = pt
+            } else {
+                let odd = Data([0x03]) + senderPubkeyData
+                plaintext = try attemptDecrypt(using: odd)
             }
-            let odd = Data([0x03]) + senderPubkeyData
-            let pt = try attemptDecrypt(using: odd)
-            return String(data: pt, encoding: .utf8) ?? ""
         } else {
-            let pt = try attemptDecrypt(using: senderPubkeyData)
-            return String(data: pt, encoding: .utf8) ?? ""
+            plaintext = try attemptDecrypt(using: senderPubkeyData)
         }
+
+        // Authenticated plaintext that is not valid UTF-8 is a malformed
+        // envelope, not an empty message.
+        guard let decoded = String(data: plaintext, encoding: .utf8) else {
+            throw NostrError.invalidCiphertext
+        }
+        return decoded
     }
     
     private static func deriveSharedSecret(
@@ -409,38 +740,8 @@ struct NostrProtocol {
         let sharedSecretData = sharedSecret.withUnsafeBytes { Data($0) }
         // ECDH shared secret derived
         
-        // Return raw ECDH shared secret; HKDF is applied by deriveNIP44V2Key
-        return sharedSecretData
-    }
-    
-    // Direct version that doesn't try to add prefixes
-    private static func deriveSharedSecretDirect(
-        privateKey: P256K.Schnorr.PrivateKey,
-        publicKey: Data
-    ) throws -> Data {
-        // Direct shared secret calculation
-        
-        // Convert Schnorr private key to KeyAgreement private key
-        let keyAgreementPrivateKey = try P256K.KeyAgreement.PrivateKey(
-            dataRepresentation: privateKey.dataRepresentation
-        )
-        
-        // Use the public key as-is (should already have prefix)
-        let keyAgreementPublicKey = try P256K.KeyAgreement.PublicKey(
-            dataRepresentation: publicKey,
-            format: .compressed
-        )
-        
-        // Perform ECDH
-        let sharedSecret = try keyAgreementPrivateKey.sharedSecretFromKeyAgreement(
-            with: keyAgreementPublicKey,
-            format: .compressed
-        )
-        
-        // Convert SharedSecret to Data
-        let sharedSecretData = sharedSecret.withUnsafeBytes { Data($0) }
-        
-        // Return raw ECDH shared secret; HKDF is applied by deriveNIP44V2Key
+        // Return raw ECDH shared secret; HKDF is applied by
+        // derivePrivateEnvelopeKey
         return sharedSecretData
     }
     
@@ -500,6 +801,10 @@ struct NostrEvent: Codable {
               let content = dict["content"] as? String else {
             throw NostrError.invalidEvent
         }
+
+        guard Self.isWithinInboundTagLimits(tags) else {
+            throw NostrError.invalidEvent
+        }
         
         self.id = dict["id"] as? String ?? ""
         self.pubkey = pubkey
@@ -509,6 +814,21 @@ struct NostrEvent: Codable {
         self.content = content
         self.sig = dict["sig"] as? String
     }
+
+    /// Bounds untrusted relay tag arrays so attackers cannot force large
+    /// allocations or expensive joins on the inbound hot path.
+    static func isWithinInboundTagLimits(_ tags: [[String]]) -> Bool {
+        guard tags.count <= TransportConfig.nostrMaxEventTags else { return false }
+
+        for tag in tags {
+            guard tag.count <= TransportConfig.nostrMaxEventTagValues else { return false }
+            guard tag.allSatisfy({ $0.utf8.count <= TransportConfig.nostrMaxEventTagValueBytes }) else {
+                return false
+            }
+        }
+
+        return true
+    }
     
     func sign(with key: P256K.Schnorr.PrivateKey) throws -> NostrEvent {
         let (eventId, eventIdHash) = try calculateEventId()
@@ -516,9 +836,12 @@ struct NostrEvent: Codable {
         // Sign with Schnorr (BIP-340)
         var messageBytes = [UInt8](eventIdHash)
         var auxRand = [UInt8](repeating: 0, count: 32)
-        _ = auxRand.withUnsafeMutableBytes { ptr in
+        let auxStatus = auxRand.withUnsafeMutableBytes { ptr in
             SecRandomCopyBytes(kSecRandomDefault, 32, ptr.baseAddress!)
         }
+        guard auxStatus == errSecSuccess else {
+            throw NostrError.cryptographicFailure
+        }
         let schnorrSignature = try key.signature(message: &messageBytes, auxiliaryRand: &auxRand)
         
         let signatureHex = schnorrSignature.dataRepresentation.hexEncodedString()
@@ -573,21 +896,23 @@ struct NostrEvent: Codable {
 
 enum NostrError: Error {
     case invalidPublicKey
-    case invalidPrivateKey
     case invalidEvent
     case invalidCiphertext
-    case signingFailed
-    case encryptionFailed
+    case cryptographicFailure
 }
 
-// MARK: - NIP-44 v2 helpers (XChaCha20-Poly1305)
+// MARK: - BitChat private-envelope key derivation
 
 private extension NostrProtocol {
-    static func deriveNIP44V2Key(from sharedSecretData: Data) throws -> Data {
+    /// The HKDF info string retains the historical "nip44-v2" label for wire
+    /// compatibility with deployed clients, but this is not the NIP-44 key
+    /// schedule: NIP-44 derives a conversation key via HKDF-extract with that
+    /// label as the *salt* and uses ChaCha20 with per-message expanded keys.
+    static func derivePrivateEnvelopeKey(from sharedSecretData: Data) throws -> Data {
         let derivedKey = HKDF<CryptoKit.SHA256>.deriveKey(
             inputKeyMaterial: SymmetricKey(data: sharedSecretData),
             salt: Data(),
-            info: "nip44-v2".data(using: .utf8)!,
+            info: Data("nip44-v2".utf8),
             outputByteCount: 32
         )
         return derivedKey.withUnsafeBytes { Data($0) }

bitchat/Nostr/NostrRelaySettings.swift

@@ -0,0 +1,92 @@
+//
+// NostrRelaySettings.swift
+// bitchat
+//
+// This is free and unencumbered software released into the public domain.
+// For more information, see <https://unlicense.org>
+//
+
+import BitLogger
+import Foundation
+
+/// Relays someone has added by hand, alongside the built-in set.
+///
+/// The built-in relays are four well-known clearnet hostnames, so a censor
+/// blocking four names ends internet-delivered private messages for everyone.
+/// Adding relays — including `.onion` addresses, or a relay run by whoever
+/// needs it — is the escape hatch that does not require shipping a new build.
+///
+/// Stored normalized so comparisons against connection keys and the built-in
+/// set are exact, and bounded so a long list cannot turn every send into a
+/// fan-out across dozens of sockets.
+enum NostrRelaySettings {
+    /// Enough to add a personal relay, an onion address, and a couple of
+    /// regional fallbacks without letting the connection fan-out grow unbounded.
+    static let maxCustomRelays = 8
+
+    private static let storageKey = "nostr.customRelays"
+
+    static let didChangeNotification = Notification.Name("bitchat.nostrRelaySettingsDidChange")
+
+    enum AddFailure: Error, Equatable {
+        case malformed
+        case alreadyPresent
+        case limitReached
+    }
+
+    /// Normalized relay URLs, in the order they were added.
+    static func customRelays(in defaults: UserDefaults = .standard) -> [String] {
+        let stored = defaults.stringArray(forKey: storageKey) ?? []
+        // Re-normalize on read: a value written by an older build, or edited
+        // outside the app, must not reach the connection layer unchecked.
+        var seen = Set<String>()
+        return stored.compactMap { NostrRelayURL.normalized($0) }
+            .filter { seen.insert($0).inserted }
+    }
+
+    /// Adds a relay, returning the normalized URL or why it was rejected.
+    @discardableResult
+    static func add(
+        _ rawValue: String,
+        builtIn: Set<String>,
+        in defaults: UserDefaults = .standard
+    ) -> Result<String, AddFailure> {
+        // Bare hostnames are the common way people quote a relay, and wss is
+        // the only sensible assumption for one.
+        guard let normalized = NostrRelayURL.normalized(rawValue, defaultScheme: "wss") else {
+            return .failure(.malformed)
+        }
+
+        var current = customRelays(in: defaults)
+        guard !current.contains(normalized), !builtIn.contains(normalized) else {
+            return .failure(.alreadyPresent)
+        }
+        guard current.count < maxCustomRelays else {
+            return .failure(.limitReached)
+        }
+
+        current.append(normalized)
+        write(current, in: defaults)
+        return .success(normalized)
+    }
+
+    static func remove(_ url: String, in defaults: UserDefaults = .standard) {
+        // Same default scheme as `add`, so a relay entered as a bare hostname
+        // can be removed the way it was typed.
+        guard let normalized = NostrRelayURL.normalized(url, defaultScheme: "wss") else { return }
+        let remaining = customRelays(in: defaults).filter { $0 != normalized }
+        write(remaining, in: defaults)
+    }
+
+    /// Panic-wipe hook: an added relay names somewhere someone chose to route
+    /// through, which is exactly the kind of trace a wipe should not leave.
+    static func reset(in defaults: UserDefaults = .standard) {
+        defaults.removeObject(forKey: storageKey)
+        NotificationCenter.default.post(name: didChangeNotification, object: nil)
+    }
+
+    private static func write(_ relays: [String], in defaults: UserDefaults) {
+        defaults.set(relays, forKey: storageKey)
+        NotificationCenter.default.post(name: didChangeNotification, object: nil)
+    }
+}

bitchat/Nostr/NostrRelayURL.swift

@@ -39,13 +39,4 @@ enum NostrRelayURL {
 
         return components.string
     }
-
-    static func directoryAddress(_ rawValue: String) -> String? {
-        guard var normalized = normalized(rawValue, defaultScheme: "wss") else { return nil }
-        for prefix in ["wss://", "ws://"] where normalized.hasPrefix(prefix) {
-            normalized.removeFirst(prefix.count)
-            break
-        }
-        return normalized
-    }
 }

bitchat/Nostr/XChaCha20Poly1305Compat.swift

@@ -132,4 +132,3 @@ private extension Data {
         replaceSubrange(offset..<(offset+4), with: bytes)
     }
 }
-

bitchat/PrivacyInfo.xcprivacy

@@ -0,0 +1,41 @@
+<?xml version="1.0" encoding="UTF-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>NSPrivacyTracking</key>
+	<false/>
+	<key>NSPrivacyTrackingDomains</key>
+	<array/>
+	<key>NSPrivacyCollectedDataTypes</key>
+	<array/>
+	<key>NSPrivacyAccessedAPITypes</key>
+	<array>
+		<dict>
+			<key>NSPrivacyAccessedAPIType</key>
+			<string>NSPrivacyAccessedAPICategoryFileTimestamp</string>
+			<key>NSPrivacyAccessedAPITypeReasons</key>
+			<array>
+				<string>C617.1</string>
+				<string>3B52.1</string>
+			</array>
+		</dict>
+		<dict>
+			<key>NSPrivacyAccessedAPIType</key>
+			<string>NSPrivacyAccessedAPICategorySystemBootTime</string>
+			<key>NSPrivacyAccessedAPITypeReasons</key>
+			<array>
+				<string>35F9.1</string>
+			</array>
+		</dict>
+		<dict>
+			<key>NSPrivacyAccessedAPIType</key>
+			<string>NSPrivacyAccessedAPICategoryUserDefaults</string>
+			<key>NSPrivacyAccessedAPITypeReasons</key>
+			<array>
+				<string>CA92.1</string>
+				<string>1C8F.1</string>
+			</array>
+		</dict>
+	</array>
+</dict>
+</plist>

bitchat/Protocols/BitchatFilePacket.swift

@@ -154,3 +154,90 @@ struct BitchatFilePacket {
         )
     }
 }
+
+/// Wire-compatible identity for private media exchanged by clients using the
+/// current iOS entropy-bearing filenames, without extending the deployed file
+/// TLV. Android clients reject unknown file tags, so eligible senders and
+/// receivers derive the receipt key from fields already on the wire.
+///
+/// Locally-created image and voice-note filenames contain a UUID or live-voice
+/// burst ID. Including the normalized direction keeps a reused filename
+/// distinct across chats while allowing short and full Noise-key peer IDs to
+/// converge. Android and older-iOS timestamp-only names remain ineligible and
+/// retain their legacy random local IDs (transfer-compatible, no receipts).
+enum PrivateMediaMessageIdentity {
+    private static let domain = Data("bitchat-private-media-message-v1".utf8)
+    private static let idPrefix = "media-"
+    private static let digestHexLength = 32
+
+    static func isStableID(_ candidate: String) -> Bool {
+        guard candidate.hasPrefix(idPrefix) else { return false }
+        let digest = candidate.dropFirst(idPrefix.count)
+        guard digest.utf8.count == digestHexLength else { return false }
+        return digest.utf8.allSatisfy { byte in
+            (UInt8(ascii: "0")...UInt8(ascii: "9")).contains(byte)
+                || (UInt8(ascii: "a")...UInt8(ascii: "f")).contains(byte)
+        }
+    }
+
+    static func stableID(
+        senderPeerID: PeerID,
+        recipientPeerID: PeerID,
+        fileName: String?
+    ) -> String? {
+        guard let fileName, !fileName.isEmpty else { return nil }
+        let leafName = (fileName as NSString).lastPathComponent
+        guard leafName == fileName else { return nil }
+
+        let path = leafName as NSString
+        let stem = path.deletingPathExtension
+        let fileExtension = path.pathExtension.lowercased()
+        switch true {
+        case stem.hasPrefix("img_"):
+            guard fileExtension == "jpg" || fileExtension == "jpeg" else { return nil }
+        case stem.hasPrefix("voice_"):
+            guard fileExtension == "m4a" else { return nil }
+        default:
+            return nil
+        }
+        let entropyToken = stem.split(separator: "_").last.map(String.init)
+        let hasUUIDEntropy = entropyToken.flatMap(UUID.init(uuidString:)) != nil
+        let voiceBurstID = stem.hasPrefix("voice_")
+            ? String(stem.dropFirst("voice_".count))
+            : ""
+        let hasBurstEntropy = voiceBurstID.count == 16
+            && voiceBurstID.allSatisfy(\.isHexDigit)
+        guard hasUUIDEntropy || hasBurstEntropy else {
+            return nil
+        }
+
+        let fields = [
+            Data(senderPeerID.toShort().bare.utf8),
+            Data(recipientPeerID.toShort().bare.utf8),
+            Data(leafName.utf8)
+        ]
+        var input = domain
+        for field in fields {
+            guard let length = UInt32(exactly: field.count) else { return nil }
+            var bigEndianLength = length.bigEndian
+            withUnsafeBytes(of: &bigEndianLength) {
+                input.append(contentsOf: $0)
+            }
+            input.append(field)
+        }
+
+        return "\(idPrefix)\(input.sha256Hex().prefix(digestHexLength))"
+    }
+
+    static func stableID(
+        for packet: BitchatFilePacket,
+        senderPeerID: PeerID,
+        recipientPeerID: PeerID
+    ) -> String? {
+        stableID(
+            senderPeerID: senderPeerID,
+            recipientPeerID: recipientPeerID,
+            fileName: packet.fileName
+        )
+    }
+}

bitchat/Protocols/BitchatProtocol.swift

@@ -18,7 +18,7 @@
 /// - Efficient binary message encoding
 /// - Message fragmentation for large payloads
 /// - TTL-based routing for mesh networks
-/// - Privacy features like padding and timing obfuscation
+/// - Privacy features: message padding and randomized relay jitter
 /// - Integration points for end-to-end encryption
 ///
 /// ## Protocol Design
@@ -38,18 +38,24 @@
 /// 7. **Decoding**: Binary data parsed back to message objects
 ///
 /// ## Security Considerations
-/// - Message padding obscures actual content length
-/// - Timing obfuscation prevents traffic analysis
+/// - Noise frames are padded (to 256/512/1024/2048-byte blocks) to obscure
+///   content length; other packet types are not padded, so their payload
+///   length is observable
+/// - Randomized relay jitter reduces the traffic-analysis signal; there is no
+///   cover traffic or per-message timing obfuscation
 /// - Integration with Noise Protocol for E2E encryption
-/// - No persistent identifiers in protocol headers
+/// - The 8-byte sender ID in every header IS a persistent identifier: it is
+///   derived from the long-lived Noise static key and rotates only on a panic
+///   wipe. Treat headers as linkable across sessions.
 ///
 /// ## Message Types
 /// - **Announce/Leave**: Peer presence notifications
-/// - **Message**: User chat messages (broadcast or directed)
+/// - **Message**: Public chat messages
 /// - **Fragment**: Multi-part message handling
-/// - **Delivery/Read**: Message acknowledgments
-/// - **Noise**: Encrypted channel establishment
-/// - **Version**: Protocol version negotiation
+/// - **NoiseHandshake/NoiseEncrypted**: Encrypted channel establishment and
+///   all private payloads (messages, delivery acks, read receipts)
+/// - **CourierEnvelope**: Sealed store-and-forward mail
+/// - **RequestSync/FileTransfer**: Gossip history sync and media transfer
 ///
 /// ## Future Extensions
 /// The protocol is designed to be extensible:
@@ -72,17 +78,53 @@ enum NoisePayloadType: UInt8 {
     case privateMessage = 0x01      // Private chat message
     case readReceipt = 0x02         // Message was read
     case delivered = 0x03           // Message was delivered
+    // Private groups (0x04/0x05 reserved by other features)
+    case groupInvite = 0x06         // Creator-signed group state (invite)
+    case groupKeyUpdate = 0x07      // Creator-signed group state (key rotation / roster update)
+    // Live voice (push-to-talk)
+    case voiceFrame = 0x08          // One live voice-burst packet (see VoiceBurstPacket)
+    // Finalized private media. `0x20` is the value already deployed by the
+    // Android client. The complete BitchatFilePacket is encrypted inside
+    // Noise before the outer noiseEncrypted packet is fragmented.
+    case privateFile = 0x20
+    // Versioned peer state authenticated by the surrounding Noise session.
+    // This is intentionally distinct from the public announce: announce
+    // capabilities are discovery hints, while this payload proves possession
+    // of the advertised Noise static key before downgrade state is pinned.
+    case authenticatedPeerState = 0x21
     // Verification (QR-based OOB binding)
     case verifyChallenge = 0x10     // Verification challenge
     case verifyResponse  = 0x11     // Verification response
-    
+    // Transitive verification (web of trust)
+    case vouch = 0x12               // Batch of vouch attestations
+
+    /// #1434 briefly used 0x09 before release. Accept it while prerelease
+    /// builds age out, but never emit it. Decoders canonicalize both values to
+    /// `.privateFile` so the compatibility alias cannot leak into app logic.
+    static let prereleasePrivateFileRawValue: UInt8 = 0x09
+
+    static func decoded(rawValue: UInt8) -> NoisePayloadType? {
+        rawValue == prereleasePrivateFileRawValue ? .privateFile : Self(rawValue: rawValue)
+    }
+
+    static func isPrivateFile(rawValue: UInt8?) -> Bool {
+        guard let rawValue else { return false }
+        return rawValue == privateFile.rawValue || rawValue == prereleasePrivateFileRawValue
+    }
+
     var description: String {
         switch self {
         case .privateMessage: return "privateMessage"
         case .readReceipt: return "readReceipt"
         case .delivered: return "delivered"
+        case .groupInvite: return "groupInvite"
+        case .groupKeyUpdate: return "groupKeyUpdate"
+        case .voiceFrame: return "voiceFrame"
+        case .privateFile: return "privateFile"
+        case .authenticatedPeerState: return "authenticatedPeerState"
         case .verifyChallenge: return "verifyChallenge"
         case .verifyResponse: return "verifyResponse"
+        case .vouch: return "vouch"
         }
     }
 }
@@ -114,6 +156,12 @@ protocol BitchatDelegate: AnyObject {
     // Low-level events for better separation of concerns
     func didReceiveNoisePayload(from peerID: PeerID, type: NoisePayloadType, payload: Data, timestamp: Date)
 
+    // Encrypted group broadcast (opaque envelope; decrypted by the group coordinator)
+    func didReceiveGroupMessage(payload: Data, timestamp: Date)
+
+    // Public live-voice burst packet (signature-verified by the transport)
+    func didReceivePublicVoiceFrame(from peerID: PeerID, nickname: String, payload: Data, timestamp: Date)
+
     // Bluetooth state updates for user notifications
     func didUpdateBluetoothState(_ state: CBManagerState)
     func didReceivePublicMessage(from peerID: PeerID, nickname: String, content: String, timestamp: Date, messageID: String?)
@@ -133,6 +181,14 @@ extension BitchatDelegate {
         // Default empty implementation
     }
 
+    func didReceiveGroupMessage(payload: Data, timestamp: Date) {
+        // Default empty implementation
+    }
+
+    func didReceivePublicVoiceFrame(from peerID: PeerID, nickname: String, payload: Data, timestamp: Date) {
+        // Default empty implementation
+    }
+
     func didReceivePublicMessage(from peerID: PeerID, nickname: String, content: String, timestamp: Date, messageID: String?) {
         // Default empty implementation
     }

bitchat/Protocols/BoardPackets.swift

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

bitchat/Protocols/Geohash.swift

@@ -10,11 +10,11 @@ enum Geohash {
         return map
     }()
 
-    /// Validates a geohash string for building-level precision (8 characters).
+    /// Validates a geohash string at any channel precision (1-12 characters).
     /// - Parameter geohash: The geohash string to validate
-    /// - Returns: true if valid 8-character base32 geohash, false otherwise
-    static func isValidBuildingGeohash(_ geohash: String) -> Bool {
-        guard geohash.count == 8 else { return false }
+    /// - Returns: true if a non-empty base32 geohash of at most 12 characters
+    static func isValidGeohash(_ geohash: String) -> Bool {
+        guard (1...12).contains(geohash.count) else { return false }
         return geohash.lowercased().allSatisfy { base32Map[$0] != nil }
     }
 

bitchat/Protocols/LocationChannel.swift

@@ -18,7 +18,7 @@ enum GeohashChannelLevel: CaseIterable, Codable, Equatable {
         case .city: return 5
         case .province: return 4
         case .region: return 2
-    }
+        }
     }
 
     var displayName: String {

bitchat/Protocols/MeshMessageIdentity.swift

@@ -0,0 +1,32 @@
+//
+// MeshMessageIdentity.swift
+// bitchat
+//
+// This is free and unencumbered software released into the public domain.
+// For more information, see <https://unlicense.org>
+//
+
+import BitFoundation
+import Foundation
+
+/// Content-derived identity for public mesh messages.
+///
+/// The BLE wire carries no message ID for public broadcasts, so every device
+/// recomputes the same stable ID from the signed wire fields (sender ID,
+/// millisecond timestamp, content). That gives the mesh bridge a
+/// cross-device-consistent radio identity with zero wire change. Bridge events
+/// carry this value only as a hint for detecting a radio copy that is already
+/// present: sender/timestamp/content are public, so a different Nostr signer
+/// can copy them and must never be allowed to reserve the genuine event's
+/// authenticated dedup slot.
+enum MeshMessageIdentity {
+    /// Matches the wire truncation in `BLEService.sendMessage`.
+    static func millisecondTimestamp(_ date: Date) -> UInt64 {
+        UInt64(date.timeIntervalSince1970 * 1000)
+    }
+
+    static func stableID(senderIDHex: String, timestampMs: UInt64, content: String) -> String {
+        let input = senderIDHex.lowercased() + "|" + String(timestampMs) + "|" + content.trimmed
+        return String(Data(input.utf8).sha256Hex().prefix(32))
+    }
+}

bitchat/Protocols/NostrCarrierPacket.swift

@@ -0,0 +1,144 @@
+//
+// NostrCarrierPacket.swift
+// bitchat
+//
+// This is free and unencumbered software released into the public domain.
+// For more information, see <https://unlicense.org>
+//
+
+import BitFoundation
+import Foundation
+
+/// Wire payload for `MessageType.nostrCarrier` (0x28): a complete, signed
+/// Nostr event ferried over the mesh between a mesh-only peer and an
+/// internet gateway peer.
+///
+/// - `toGateway` rides a DIRECTED packet (recipientID = the gateway peer):
+///   a mesh-only sender asks the gateway to publish its locally signed
+///   geohash event to Nostr relays.
+/// - `fromGateway` rides a BROADCAST packet (default TTL): the gateway
+///   rebroadcasts inbound relay events so mesh-only peers see the channel.
+///
+/// The carried event is public geohash chat — already plaintext on Nostr —
+/// so the carrier adds no encryption. It IS signed by the originator's
+/// per-geohash identity, so neither the gateway nor any mesh relay can forge
+/// or alter it undetected: gateways and receivers verify the Schnorr
+/// signature before acting on it.
+///
+/// TLV encoding with 2-byte big-endian lengths (the event JSON exceeds the
+/// 1-byte TLV range used by smaller packets). Unknown TLV types are skipped
+/// for forward compatibility.
+struct NostrCarrierPacket: Equatable {
+    enum Direction: UInt8 {
+        case toGateway = 0x01
+        case fromGateway = 0x02
+        /// Mesh-bridge uplink: a mesh-only peer asks a bridge gateway to
+        /// publish its signed rendezvous event. Directed, like `toGateway`.
+        case toBridge = 0x03
+        /// Mesh-bridge downlink: a bridge gateway rebroadcasts a rendezvous
+        /// event from a remote island. Broadcast, like `fromGateway`.
+        /// Old clients fail the Direction decode on 0x03/0x04 and drop the
+        /// carrier quietly — bridge traffic degrades to invisible, not junk.
+        case fromBridge = 0x04
+    }
+
+    let direction: Direction
+    let geohash: String
+    /// Complete signed Nostr event JSON (id, pubkey, created_at, kind, tags,
+    /// content, sig).
+    let eventJSON: Data
+
+    /// BLE airtime cap for a carried event.
+    static let maxEventJSONBytes = 16 * 1024
+    static let maxGeohashLength = 12
+
+    private enum TLVType: UInt8 {
+        case direction = 0x01
+        case geohash = 0x02
+        case eventJSON = 0x03
+    }
+
+    init?(direction: Direction, geohash: String, eventJSON: Data) {
+        let geohashBytes = Data(geohash.utf8)
+        guard !geohashBytes.isEmpty,
+              geohashBytes.count <= Self.maxGeohashLength,
+              !eventJSON.isEmpty,
+              eventJSON.count <= Self.maxEventJSONBytes else {
+            return nil
+        }
+        self.direction = direction
+        self.geohash = geohash
+        self.eventJSON = eventJSON
+    }
+
+    init?(direction: Direction, geohash: String, event: NostrEvent) {
+        guard let json = try? event.jsonString(), !json.isEmpty else { return nil }
+        self.init(direction: direction, geohash: geohash, eventJSON: Data(json.utf8))
+    }
+
+    /// Decodes the carried event. Callers MUST still verify
+    /// `event.isValidSignature()` before publishing or displaying it.
+    func event() -> NostrEvent? {
+        guard let dict = try? JSONSerialization.jsonObject(with: eventJSON) as? [String: Any] else {
+            return nil
+        }
+        return try? NostrEvent(from: dict)
+    }
+
+    func encode() -> Data? {
+        var data = Data()
+        data.reserveCapacity(eventJSON.count + geohash.utf8.count + 12)
+
+        func appendTLV(_ type: TLVType, _ value: Data) {
+            data.append(type.rawValue)
+            data.append(UInt8((value.count >> 8) & 0xFF))
+            data.append(UInt8(value.count & 0xFF))
+            data.append(value)
+        }
+
+        appendTLV(.direction, Data([direction.rawValue]))
+        appendTLV(.geohash, Data(geohash.utf8))
+        appendTLV(.eventJSON, eventJSON)
+        return data
+    }
+
+    static func decode(_ data: Data) -> NostrCarrierPacket? {
+        // Defensive slice re-base (Data slices keep parent indices).
+        let data = Data(data)
+        var offset = 0
+        var direction: Direction?
+        var geohash: String?
+        var eventJSON: Data?
+
+        while offset + 3 <= data.count {
+            let typeRaw = data[offset]
+            let length = (Int(data[offset + 1]) << 8) | Int(data[offset + 2])
+            offset += 3
+            guard offset + length <= data.count else { return nil }
+            let value = data.subdata(in: offset..<offset + length)
+            offset += length
+
+            switch TLVType(rawValue: typeRaw) {
+            case .direction:
+                guard value.count == 1, let parsed = Direction(rawValue: value[0]) else { return nil }
+                direction = parsed
+            case .geohash:
+                guard let parsed = String(data: value, encoding: .utf8) else { return nil }
+                geohash = parsed
+            case .eventJSON:
+                eventJSON = value
+            case nil:
+                // Unknown TLV; skip (tolerant decoder for forward compatibility).
+                continue
+            }
+        }
+
+        guard offset == data.count,
+              let direction,
+              let geohash,
+              let eventJSON else {
+            return nil
+        }
+        return NostrCarrierPacket(direction: direction, geohash: geohash, eventJSON: eventJSON)
+    }
+}

bitchat/Protocols/Packets.swift

@@ -1,3 +1,4 @@
+import BitFoundation
 import Foundation
 
 // MARK: - Protocol TLV Packets
@@ -7,12 +8,35 @@ struct AnnouncementPacket {
     let noisePublicKey: Data            // Noise static public key (Curve25519.KeyAgreement)
     let signingPublicKey: Data          // Ed25519 public key for signing
     let directNeighbors: [Data]?        // 8-byte peer IDs
+    let capabilities: PeerCapabilities? // advertised feature bits; nil when absent (old clients)
+    /// Rendezvous geohash cell this peer bridges, when advertising `.bridge`.
+    /// Coarse (cell-level) by design; lets mesh-only peers compose correctly
+    /// tagged rendezvous events without their own location fix.
+    let bridgeGeohash: String?
+
+    init(
+        nickname: String,
+        noisePublicKey: Data,
+        signingPublicKey: Data,
+        directNeighbors: [Data]?,
+        capabilities: PeerCapabilities? = nil,
+        bridgeGeohash: String? = nil
+    ) {
+        self.nickname = nickname
+        self.noisePublicKey = noisePublicKey
+        self.signingPublicKey = signingPublicKey
+        self.directNeighbors = directNeighbors
+        self.capabilities = capabilities
+        self.bridgeGeohash = bridgeGeohash
+    }
 
     private enum TLVType: UInt8 {
         case nickname = 0x01
         case noisePublicKey = 0x02
         case signingPublicKey = 0x03
         case directNeighbors = 0x04
+        case capabilities = 0x05
+        case bridgeGeohash = 0x06
     }
 
     func encode() -> Data? {
@@ -48,6 +72,24 @@ struct AnnouncementPacket {
             }
         }
 
+        // TLV for capabilities (optional)
+        if let capabilities = capabilities {
+            let capabilityBytes = capabilities.encoded()
+            guard capabilityBytes.count <= 255 else { return nil }
+            data.append(TLVType.capabilities.rawValue)
+            data.append(UInt8(capabilityBytes.count))
+            data.append(capabilityBytes)
+        }
+
+        // TLV for bridge rendezvous cell (optional; old clients skip it)
+        if let bridgeGeohash = bridgeGeohash,
+           let cellData = bridgeGeohash.data(using: .utf8),
+           !cellData.isEmpty, cellData.count <= 12 {
+            data.append(TLVType.bridgeGeohash.rawValue)
+            data.append(UInt8(cellData.count))
+            data.append(cellData)
+        }
+
         return data
     }
 
@@ -57,6 +99,8 @@ struct AnnouncementPacket {
         var noisePublicKey: Data?
         var signingPublicKey: Data?
         var directNeighbors: [Data]?
+        var capabilities: PeerCapabilities?
+        var bridgeGeohash: String?
 
         while offset + 2 <= data.count {
             let typeRaw = data[offset]
@@ -87,6 +131,12 @@ struct AnnouncementPacket {
                         }
                         directNeighbors = neighbors
                     }
+                case .capabilities:
+                    capabilities = PeerCapabilities(encoded: Data(value))
+                case .bridgeGeohash:
+                    if length <= 12 {
+                        bridgeGeohash = String(data: value, encoding: .utf8)
+                    }
                 }
             } else {
                 // Unknown TLV; skip (tolerant decoder for forward compatibility)
@@ -99,7 +149,92 @@ struct AnnouncementPacket {
             nickname: nickname,
             noisePublicKey: noisePublicKey,
             signingPublicKey: signingPublicKey,
-            directNeighbors: directNeighbors
+            directNeighbors: directNeighbors,
+            capabilities: capabilities,
+            bridgeGeohash: bridgeGeohash
+        )
+    }
+}
+
+/// State that is authoritative only because it is carried inside an
+/// established Noise session. The public announce remains useful for
+/// discovery, but its self-signature cannot prove possession of the copied
+/// Noise public key it contains.
+///
+/// Wire format (v1):
+/// `[version=0x01][type][length][value]...`
+/// - TLV `0x01`: canonical minimal little-endian `PeerCapabilities`
+/// - TLV `0x02`: 32-byte Ed25519 signing public key
+///
+/// Unknown TLVs are skipped for forward compatibility. Unknown versions,
+/// duplicates, non-canonical capability fields, and malformed lengths are
+/// rejected without changing authenticated state.
+struct AuthenticatedPeerStatePacket: Equatable {
+    static let currentVersion: UInt8 = 1
+    static let signingPublicKeyLength = 32
+
+    let capabilities: PeerCapabilities
+    let signingPublicKey: Data
+
+    private enum TLVType: UInt8 {
+        case capabilities = 0x01
+        case signingPublicKey = 0x02
+    }
+
+    func encode() -> Data? {
+        guard signingPublicKey.count == Self.signingPublicKeyLength else { return nil }
+        let capabilityBytes = capabilities.encoded()
+        guard !capabilityBytes.isEmpty, capabilityBytes.count <= 8 else { return nil }
+
+        var data = Data([Self.currentVersion])
+        data.append(TLVType.capabilities.rawValue)
+        data.append(UInt8(capabilityBytes.count))
+        data.append(capabilityBytes)
+        data.append(TLVType.signingPublicKey.rawValue)
+        data.append(UInt8(signingPublicKey.count))
+        data.append(signingPublicKey)
+        return data
+    }
+
+    static func decode(from data: Data) -> AuthenticatedPeerStatePacket? {
+        guard data.first == Self.currentVersion else { return nil }
+
+        var offset = 1
+        var capabilities: PeerCapabilities?
+        var signingPublicKey: Data?
+
+        while offset < data.count {
+            guard offset + 2 <= data.count else { return nil }
+            let typeRaw = data[offset]
+            let length = Int(data[offset + 1])
+            offset += 2
+            guard offset + length <= data.count else { return nil }
+            let value = Data(data[offset..<(offset + length)])
+            offset += length
+
+            guard let type = TLVType(rawValue: typeRaw) else {
+                continue
+            }
+            switch type {
+            case .capabilities:
+                guard capabilities == nil,
+                      !value.isEmpty,
+                      value.count <= 8 else { return nil }
+                let decoded = PeerCapabilities(encoded: value)
+                guard decoded.encoded() == value else { return nil }
+                capabilities = decoded
+
+            case .signingPublicKey:
+                guard signingPublicKey == nil,
+                      value.count == Self.signingPublicKeyLength else { return nil }
+                signingPublicKey = value
+            }
+        }
+
+        guard let capabilities, let signingPublicKey else { return nil }
+        return AuthenticatedPeerStatePacket(
+            capabilities: capabilities,
+            signingPublicKey: signingPublicKey
         )
     }
 }

bitchat/Protocols/PeerCapabilities+Local.swift

@@ -0,0 +1,13 @@
+import BitFoundation
+
+extension PeerCapabilities {
+    /// Capabilities this build advertises in its announce packets.
+    /// Each feature adds its bit here when it ships.
+    static let localSupported: PeerCapabilities = [
+        .vouch,
+        .prekeys,
+        .groups,
+        .privateMedia,
+        .privateMediaReceipts
+    ]
+}