diff --git a/.github/workflows/intel-x64-verify.yml b/.github/workflows/intel-x64-verify.yml
index a9f7b089..4f8efe8d 100644
--- a/.github/workflows/intel-x64-verify.yml
+++ b/.github/workflows/intel-x64-verify.yml
@@ -32,7 +32,7 @@ jobs:
 
       - name: download published x64 DMG
         run: |
-          curl -sSL -o /tmp/x64.dmg "https://github.com/${{ github.repository }}/releases/latest/download/OpenSwarm-x64.dmg"
+          curl -sSL -o /tmp/x64.dmg "https://github.com/openswarm-ai/openswarm/releases/latest/download/OpenSwarm-x64.dmg"
           ls -la /tmp/x64.dmg
           hdiutil attach -nobrowse -readonly -mountpoint /tmp/oswmnt /tmp/x64.dmg
           mkdir -p /tmp/oswapp
@@ -106,7 +106,7 @@ jobs:
       - name: download published Setup.exe
         shell: pwsh
         run: |
-          curl.exe -sSL -o $env:TEMP\OpenSwarm-Setup-x64.exe "https://github.com/${{ github.repository }}/releases/latest/download/OpenSwarm-Setup-x64.exe"
+          curl.exe -sSL -o $env:TEMP\OpenSwarm-Setup-x64.exe "https://github.com/openswarm-ai/openswarm/releases/latest/download/OpenSwarm-Setup-x64.exe"
           Get-Item $env:TEMP\OpenSwarm-Setup-x64.exe | Select-Object Name,Length
 
       - name: silent install (Squirrel)
diff --git a/.github/workflows/promotion-gate.yml b/.github/workflows/promotion-gate.yml
index 8a94f4b3..6464fda7 100644
--- a/.github/workflows/promotion-gate.yml
+++ b/.github/workflows/promotion-gate.yml
@@ -9,9 +9,10 @@ name: Promotion gate (update feeds agree)
 # missing or versions mismatch, this goes red so the bad release is caught
 # before users auto-update into it.
 
+# Release events fire in the repo that HOLDS the releases: the public shell (openswarm-ai/openswarm).
+# The copy that answers them lives in release-shell/.github/workflows/promotion-gate.yml and is pushed
+# by scripts/release/sync-shell.sh; this one is the by-hand form for the repo that builds.
 on:
-  release:
-    types: [published, released, prereleased]
   workflow_dispatch:
     inputs:
       tag:
@@ -44,7 +45,7 @@ jobs:
         shell: bash
         run: |
           mkdir -p feeds
-          gh release download "${{ steps.tag.outputs.tag }}" --repo "${{ github.repository }}" \
+          gh release download "${{ steps.tag.outputs.tag }}" --repo openswarm-ai/openswarm \
             -p 'latest*.yml' -D feeds || true
           ls -la feeds
       - name: Verify both feeds exist, agree, and resolve
@@ -53,4 +54,4 @@ jobs:
           node scripts/release/verify-release.js \
             --dir feeds \
             --expect-version "${{ steps.tag.outputs.ver }}" \
-            --base-url "https://github.com/${{ github.repository }}/releases/download/${{ steps.tag.outputs.tag }}"
+            --base-url "https://github.com/openswarm-ai/openswarm/releases/download/${{ steps.tag.outputs.tag }}"
diff --git a/.github/workflows/release-macos.yml b/.github/workflows/release-macos.yml
index 1931a214..9683e854 100644
--- a/.github/workflows/release-macos.yml
+++ b/.github/workflows/release-macos.yml
@@ -99,13 +99,22 @@ jobs:
         shell: bash
         run: python3 -m pip install --upgrade castlabs-evs
 
+      - name: The release shell must be reachable with the release token
+        # Releases live in the public shell every installed updater polls (openswarm-ai/openswarm),
+        # never in the repo that builds them, and a workflow's own token cannot write outside its repo.
+        if: ${{ env.APPLE_ID != '' && (github.event_name == 'push' || github.event.inputs.publish == 'true') }}
+        shell: bash
+        env:
+          GH_TOKEN: ${{ secrets.RELEASE_SHELL_TOKEN }}
+        run: bash scripts/release/check-shell-token.sh
+
       - name: Build app
         # Skip (green) when Apple signing secrets aren't in CI: Mac ships via local
         # publish.sh, so a secret-less CI run should no-op, not fail red.
         if: ${{ env.APPLE_ID != '' }}
         shell: bash
         env:
-          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          GH_TOKEN: ${{ secrets.RELEASE_SHELL_TOKEN }}
           GOOGLE_OAUTH_CLIENT_ID:     ${{ secrets.GOOGLE_OAUTH_CLIENT_ID }}
           GOOGLE_OAUTH_CLIENT_SECRET: ${{ secrets.GOOGLE_OAUTH_CLIENT_SECRET }}
         run: |
diff --git a/.github/workflows/release-windows.yml b/.github/workflows/release-windows.yml
index 82340530..aa43c7cb 100644
--- a/.github/workflows/release-windows.yml
+++ b/.github/workflows/release-windows.yml
@@ -138,10 +138,19 @@ jobs:
           "SIGNTOOL_PATH=$signtool" | Out-File -FilePath $env:GITHUB_ENV -Append -Encoding utf8
           Write-Host "SIGNTOOL_PATH=$signtool"
 
+      - name: The release shell must be reachable with the release token
+        # Releases live in the public shell every installed updater polls (openswarm-ai/openswarm),
+        # never in the repo that builds them, and a workflow's own token cannot write outside its repo.
+        if: github.event_name == 'push' || (github.event_name == 'workflow_dispatch' && github.event.inputs.publish == 'true')
+        shell: bash
+        env:
+          GH_TOKEN: ${{ secrets.RELEASE_SHELL_TOKEN }}
+        run: bash scripts/release/check-shell-token.sh
+
       - name: Build app
         shell: pwsh
         env:
-          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          GH_TOKEN: ${{ secrets.RELEASE_SHELL_TOKEN }}
           GOOGLE_OAUTH_CLIENT_ID:     ${{ secrets.GOOGLE_OAUTH_CLIENT_ID }}
           GOOGLE_OAUTH_CLIENT_SECRET: ${{ secrets.GOOGLE_OAUTH_CLIENT_SECRET }}
         run: |
@@ -206,7 +215,9 @@ jobs:
         if: github.event_name == 'push' || (github.event_name == 'workflow_dispatch' && github.event.inputs.publish == 'true')
         shell: pwsh
         env:
-          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          GH_TOKEN: ${{ secrets.RELEASE_SHELL_TOKEN }}
+          # Every gh release call below lands in the shell, whatever repo this workflow runs in.
+          GH_REPO: openswarm-ai/openswarm
         run: |
           $ErrorActionPreference = 'Stop'
           $version = (Get-Content electron/package.json | ConvertFrom-Json).version
diff --git a/.github/workflows/smoke-windows-packaged.yml b/.github/workflows/smoke-windows-packaged.yml
index b09b414a..e367f066 100644
--- a/.github/workflows/smoke-windows-packaged.yml
+++ b/.github/workflows/smoke-windows-packaged.yml
@@ -46,6 +46,8 @@ jobs:
       - name: Download the shipped installer
         env:
           GH_TOKEN: ${{ github.token }}
+          # Draft releases sit in the public shell and are readable only with a token that can see it.
+          RELEASE_SHELL_TOKEN: ${{ secrets.RELEASE_SHELL_TOKEN }}
         run: |
           $exe = Join-Path $env:RUNNER_TEMP "OpenSwarm-Setup-x64.exe"
           $runId = "${{ inputs.run_id }}"
@@ -68,14 +70,15 @@ jobs:
           # "release not found" even though the assets are right there. Resolve it out of the full
           # list and pull the asset by id, which works for drafts and published releases alike.
           $tag = "${{ inputs.tag || 'v1.7.0' }}"
-          $rel = gh api "repos/$env:GITHUB_REPOSITORY/releases?per_page=50" | ConvertFrom-Json |
+          if ($env:RELEASE_SHELL_TOKEN) { $env:GH_TOKEN = $env:RELEASE_SHELL_TOKEN }
+          $rel = gh api "repos/openswarm-ai/openswarm/releases?per_page=50" | ConvertFrom-Json |
                  Where-Object { $_.tag_name -eq $tag } | Select-Object -First 1
           if (-not $rel) { throw "no release (draft or published) tagged $tag" }
           "release: $($rel.tag_name) draft=$($rel.draft)"
           $asset = $rel.assets | Where-Object { $_.name -eq 'OpenSwarm-Setup-x64.exe' } | Select-Object -First 1
           if (-not $asset) { throw "OpenSwarm-Setup-x64.exe is not attached to $tag" }
           $exe = Join-Path $env:RUNNER_TEMP "OpenSwarm-Setup-x64.exe"
-          gh api -H "Accept: application/octet-stream" "repos/$env:GITHUB_REPOSITORY/releases/assets/$($asset.id)" > $exe
+          gh api -H "Accept: application/octet-stream" "repos/openswarm-ai/openswarm/releases/assets/$($asset.id)" > $exe
           $size = (Get-Item $exe).Length
           "installer: $size bytes (release says $($asset.size))"
           if ($size -ne $asset.size) { throw "FAIL: download is truncated" }
diff --git a/.github/workflows/suites-matrix.yml b/.github/workflows/suites-matrix.yml
index 28baa561..46e77f39 100644
--- a/.github/workflows/suites-matrix.yml
+++ b/.github/workflows/suites-matrix.yml
@@ -4,6 +4,10 @@ name: Suites on every OS
 # CI ran a hermetic subset on Ubuntu. Users run a 2017 iMac, Intel Macs and Windows laptops, so the
 # full suites run on the three hosted OSes. fail-fast is off and every suite runs even after a red
 # one, so one run reports all nine verdicts.
+#
+# A private repo bills macOS minutes at ten times Linux; the two Mac legs ran 579 minutes in the
+# fortnight before the move (5,790 billable against a 2,000-minute month), so a push runs the Windows
+# leg, which no developer machine here can run, and a dispatch runs all three.
 on:
   workflow_dispatch:
   push:
@@ -22,7 +26,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [macos-latest, macos-15-intel, windows-latest]
+        os: ${{ github.event_name == 'push' && fromJSON('["windows-latest"]') || fromJSON('["macos-latest", "macos-15-intel", "windows-latest"]') }}
     runs-on: ${{ matrix.os }}
     timeout-minutes: 60
     env:
diff --git a/docs/RELEASE_RUNBOOK.md b/docs/RELEASE_RUNBOOK.md
index fd9410ed..cfcc0d41 100644
--- a/docs/RELEASE_RUNBOOK.md
+++ b/docs/RELEASE_RUNBOOK.md
@@ -71,6 +71,28 @@ Recommended order so neither platform's users skip a version:
 3. Verify both `latest.yml` and `latest-mac.yml` exist on the release and their
    versions match before the release leaves draft.
 
+### Releases live in the public shell, whatever repo builds them
+
+Every installed copy polls `github.com/openswarm-ai/openswarm` for updates (the
+electron-updater feed comes from `electron/package.json`'s `publish` block, the
+Windows Squirrel feed is a literal URL in `electron/main.js`), and the landing
+page's download links point at that repo's `releases/latest`. So that repo is the
+release shell and must stay public with its releases and tags intact; the code
+that builds a release may live anywhere else.
+
+- The release workflows publish with `RELEASE_SHELL_TOKEN`, a fine-grained token
+  with Contents read and write on the shell only. A workflow's own token cannot
+  write outside its repo, so `scripts/release/check-shell-token.sh` runs before a
+  publishing build and fails closed when the token is missing or read-only.
+- `publish.sh` exports `GH_REPO=openswarm-ai/openswarm`, so every `gh release`
+  call and the ENG-319 dangling-tag guard act on the shell.
+- `promotion-gate.yml` fires on release events, which happen in the shell, so the
+  live copy of that workflow is the one in `release-shell/`; `scripts/release/sync-shell.sh`
+  publishes that directory as the shell's `main` (dry run by default). The shell
+  also keeps `electron/build/icon.ico` at its old path because the Squirrel
+  installer fetches its icon from `raw.githubusercontent.com` on `main`.
+- `electron/releaseShell.test.js` pins all of the above.
+
 ## Auto-update verification (before promoting)
 
 The auto-updater (electron-updater) checks GitHub Releases on launch and every
diff --git a/electron/releaseShell.test.js b/electron/releaseShell.test.js
new file mode 100644
index 00000000..2a9185f9
--- /dev/null
+++ b/electron/releaseShell.test.js
@@ -0,0 +1,76 @@
+// Every installed copy polls github.com/openswarm-ai/openswarm for updates, and the landing page links
+// its downloads there. When the source moves to a private repo that public repo becomes a releases-only
+// shell, so every path that publishes or downloads a build must name the shell, never "the repo I run in".
+const test = require('node:test');
+const assert = require('node:assert');
+const fs = require('fs');
+const path = require('path');
+const pkg = require('./package.json');
+
+const SHELL = 'openswarm-ai/openswarm';
+const root = path.join(__dirname, '..');
+const read = (rel) => fs.readFileSync(path.join(root, rel), 'utf8');
+
+test('electron-builder publishes into the shell', () => {
+  assert.deepStrictEqual(pkg.build.publish, { provider: 'github', owner: 'openswarm-ai', repo: 'openswarm' });
+});
+
+test('both updater feeds in main.js point at the shell', () => {
+  const main = read('electron/main.js');
+  assert.ok(main.includes(`https://github.com/${SHELL}/releases/latest/download/RELEASES`), 'the Squirrel probe');
+  assert.ok(main.includes(`setFeedURL({ url: 'https://github.com/${SHELL}/releases/latest/download/' })`), 'the Squirrel feed');
+});
+
+test('the Windows installer icon and alias upload name the shell', () => {
+  const ps1 = read('scripts/build-app-win.ps1');
+  assert.ok(ps1.includes(`https://raw.githubusercontent.com/${SHELL}/main/electron/build/icon.ico`), 'Squirrel reads the icon off the shell main branch');
+  assert.ok(ps1.includes(`gh release upload "v$version" $AliasExe --repo ${SHELL} --clobber`));
+  assert.ok(fs.existsSync(path.join(root, 'release-shell/electron/build/icon.ico')), 'the shell must keep the icon at that path');
+});
+
+test('every release workflow publishes with the shell token and names the shell', () => {
+  for (const wf of ['release-macos.yml', 'release-windows.yml']) {
+    const y = read(`.github/workflows/${wf}`);
+    const check = y.indexOf('run: bash scripts/release/check-shell-token.sh');
+    const build = y.indexOf('- name: Build app');
+    assert.ok(check > 0 && check < build, `${wf}: the shell check runs before the build`);
+    const buildEnv = y.slice(build, y.indexOf('run:', build));
+    assert.ok(buildEnv.includes('GH_TOKEN: ${{ secrets.RELEASE_SHELL_TOKEN }}'), `${wf}: the build publishes with the shell token`);
+    assert.ok(!y.includes('GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}'), `${wf}: a workflow token only writes to its own repo`);
+  }
+  const win = read('.github/workflows/release-windows.yml');
+  assert.ok(win.includes(`GH_REPO: ${SHELL}`), 'gh release calls on Windows land in the shell');
+});
+
+test('no download or gate path reads the repo it runs in', () => {
+  for (const wf of ['promotion-gate.yml', 'intel-x64-verify.yml', 'smoke-windows-packaged.yml']) {
+    const y = read(`.github/workflows/${wf}`);
+    assert.ok(!y.includes('github.repository') && !y.includes('GITHUB_REPOSITORY'), `${wf} must name ${SHELL}`);
+    assert.ok(y.includes(SHELL), `${wf} names the shell`);
+  }
+});
+
+test('the source repo gate is by hand and the shell copy answers release events', () => {
+  assert.ok(!read('.github/workflows/promotion-gate.yml').includes('\n  release:'), 'release events never fire in the build repo');
+  const shellGate = read('release-shell/.github/workflows/promotion-gate.yml');
+  assert.ok(shellGate.includes('\n  release:\n    types: [published, released, prereleased]'));
+  assert.ok(shellGate.includes('node scripts/release/verify-release.js'));
+});
+
+test('the shell carries byte-identical copies of what its gate and installer need', () => {
+  for (const rel of ['scripts/release/verify-release.js', 'electron/build/icon.ico']) {
+    assert.ok(fs.readFileSync(path.join(root, rel)).equals(fs.readFileSync(path.join(root, 'release-shell', rel))), `${rel} drifted`);
+  }
+});
+
+test('publish.sh sends releases and the ENG-319 tag guard to the shell, not to origin', () => {
+  const sh = read('publish.sh');
+  assert.ok(sh.includes(`export GH_REPO="\${GH_REPO:-${SHELL}}"`));
+  assert.ok(sh.includes('gh api -X DELETE "repos/$GH_REPO/git/refs/tags/v$VERSION"'));
+  assert.ok(!sh.includes('git push origin ":refs/tags/'), 'the build repo tag is not the feed tag');
+});
+
+test('a push runs only the Windows suite leg; Mac minutes are spent on purpose', () => {
+  const y = read('.github/workflows/suites-matrix.yml');
+  assert.ok(y.includes(`os: \${{ github.event_name == 'push' && fromJSON('["windows-latest"]') || fromJSON('["macos-latest", "macos-15-intel", "windows-latest"]') }}`));
+});
diff --git a/publish.sh b/publish.sh
index e9dc8763..d0c10239 100755
--- a/publish.sh
+++ b/publish.sh
@@ -26,6 +26,9 @@ PROJECT_ROOT="$(dirname "$PUBLISH_ABSPATH")"
 cd "$PROJECT_ROOT"
 # Local release credentials (Apple notarization + castlabs EVS/Widevine), gitignored. Sourcing here means a push never stalls on a missing cred once .release.env exists. See .release.env.example.
 if [ -f "$PROJECT_ROOT/.release.env" ]; then set -a; . "$PROJECT_ROOT/.release.env"; set +a; echo "==> sourced .release.env"; fi
+# Releases live in the public shell every installed updater polls, whatever repo this checkout came from.
+export GH_REPO="${GH_REPO:-openswarm-ai/openswarm}"
+echo "==> releases go to $GH_REPO"
 
 # electron-builder auto-detects prerelease from semver suffix in electron/package.json
 # (e.g. "1.0.37-exp.1" publishes as GitHub Pre-release; "1.0.37" publishes as stable).
@@ -50,9 +53,10 @@ if [[ "$VERSION" == *-* ]]; then
     # ENG-319 guard: a git tag on origin whose release is a DRAFT poisons releases.atom (the feed
     # lists bare tags), so every experimental updater resolves it first and 404s on its assets.
     # This broke "check for updates" fleet-wide for hours on 2026-08-19. Kill it here, always.
-    if git ls-remote --tags origin "refs/tags/v$VERSION" | grep -q .; then
-        echo "==> ENG-319 guard: deleting dangling remote tag v$VERSION (release is a draft; a public tag would 404 every experimental updater)"
-        git push origin ":refs/tags/v$VERSION" || echo "WARN: could not delete remote tag v$VERSION; DELETE IT MANUALLY or updaters 404"
+    # The feed is the shell's, so the tag that matters is the shell's, not the build repo's.
+    if gh api "repos/$GH_REPO/git/ref/tags/v$VERSION" >/dev/null 2>&1; then
+        echo "==> ENG-319 guard: deleting dangling tag v$VERSION on $GH_REPO (release is a draft; a public tag would 404 every experimental updater)"
+        gh api -X DELETE "repos/$GH_REPO/git/refs/tags/v$VERSION" || echo "WARN: could not delete tag v$VERSION on $GH_REPO; DELETE IT MANUALLY or updaters 404"
     fi
 fi
 
diff --git a/release-shell/.github/workflows/promotion-gate.yml b/release-shell/.github/workflows/promotion-gate.yml
new file mode 100644
index 00000000..8a94f4b3
--- /dev/null
+++ b/release-shell/.github/workflows/promotion-gate.yml
@@ -0,0 +1,56 @@
+name: Promotion gate (update feeds agree)
+
+# The "don't let a half-baked release become latest" gate. Releases should be
+# cut as DRAFT first (publish.sh drafts experimental builds; do the same for
+# stable and only un-draft after dogfooding — see docs/RELEASE_CHECKLIST.md).
+# When a release is published / un-drafted, this verifies BOTH auto-updater
+# feeds exist, agree on version (with each other and the tag), and that every
+# referenced asset actually resolves (HEAD 200). If a platform's feed is
+# missing or versions mismatch, this goes red so the bad release is caught
+# before users auto-update into it.
+
+on:
+  release:
+    types: [published, released, prereleased]
+  workflow_dispatch:
+    inputs:
+      tag:
+        description: 'Release tag to verify (e.g. v1.2.3)'
+        required: true
+
+permissions:
+  contents: read
+
+jobs:
+  verify-feeds:
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: '20.18.1'
+      - name: Resolve tag
+        id: tag
+        shell: bash
+        run: |
+          tag="${{ github.event.release.tag_name }}"
+          [ -z "$tag" ] && tag="${{ github.event.inputs.tag }}"
+          echo "tag=$tag" >> "$GITHUB_OUTPUT"
+          echo "ver=${tag#v}" >> "$GITHUB_OUTPUT"
+      - name: Download release feeds
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        shell: bash
+        run: |
+          mkdir -p feeds
+          gh release download "${{ steps.tag.outputs.tag }}" --repo "${{ github.repository }}" \
+            -p 'latest*.yml' -D feeds || true
+          ls -la feeds
+      - name: Verify both feeds exist, agree, and resolve
+        shell: bash
+        run: |
+          node scripts/release/verify-release.js \
+            --dir feeds \
+            --expect-version "${{ steps.tag.outputs.ver }}" \
+            --base-url "https://github.com/${{ github.repository }}/releases/download/${{ steps.tag.outputs.tag }}"
diff --git a/release-shell/README.md b/release-shell/README.md
new file mode 100644
index 00000000..acfd9f0c
--- /dev/null
+++ b/release-shell/README.md
@@ -0,0 +1,19 @@
+# OpenSwarm releases
+
+This repository holds the signed builds of OpenSwarm and nothing else. Every installed copy checks here for updates, and the download links on [openswarm.com](https://openswarm.com) point here.
+
+## Download
+
+- macOS (Apple silicon): https://github.com/openswarm-ai/openswarm/releases/latest/download/OpenSwarm-arm64.dmg
+- macOS (Intel): https://github.com/openswarm-ai/openswarm/releases/latest/download/OpenSwarm-x64.dmg
+- Windows: https://github.com/openswarm-ai/openswarm/releases/latest/download/OpenSwarm-Setup-x64.exe
+
+The release marked **Latest** is the stable build. Releases marked **Pre-release** are the experimental channel, which the app offers when you turn on experimental updates in Settings.
+
+## Bugs and requests
+
+Open an issue here: https://github.com/openswarm-ai/openswarm/issues/new
+
+## Source
+
+The source code of every version up to v1.7.9 stays available under this repository's tags, under the AGPL-3.0 licence it was published with. Development continues in a private repository.
diff --git a/release-shell/electron/build/icon.ico b/release-shell/electron/build/icon.ico
new file mode 100644
index 00000000..18621b6e
Binary files /dev/null and b/release-shell/electron/build/icon.ico differ
diff --git a/release-shell/scripts/release/verify-release.js b/release-shell/scripts/release/verify-release.js
new file mode 100644
index 00000000..e8291610
--- /dev/null
+++ b/release-shell/scripts/release/verify-release.js
@@ -0,0 +1,118 @@
+#!/usr/bin/env node
+// Phase 5a promotion gate: before a draft release is allowed to become "latest",
+// prove both auto-updater feeds exist, agree on version, and that their assets
+// actually resolve. A release that ships latest.yml but not latest-mac.yml (or
+// with mismatched versions) silently strands one platform's users on the old
+// build, which is the exact "broken latest" failure this gate exists to stop.
+//
+// Usage:
+//   node scripts/release/verify-release.js --dir <artifacts-dir> --expect-version 1.2.3
+//   node scripts/release/verify-release.js --dir <dir> --expect-version 1.2.3 \
+//        --base-url https://github.com/openswarm-ai/openswarm/releases/download/v1.2.3
+//
+// --dir            directory containing latest.yml + latest-mac.yml
+// --expect-version version both feeds (and their filenames) must match
+// --base-url       if given, HEAD-check every referenced asset resolves (200)
+//
+// Exit 0 = promotable. Exit 1 = blocked (prints the first blocking reason).
+
+'use strict';
+const fs = require('fs');
+const path = require('path');
+const https = require('https');
+
+const FEEDS = ['latest.yml', 'latest-mac.yml'];
+
+function parseArgs(argv) {
+  const out = { dir: null, expectVersion: null, baseUrl: null, json: false };
+  for (let i = 0; i < argv.length; i++) {
+    if (argv[i] === '--dir') out.dir = argv[++i];
+    else if (argv[i] === '--expect-version') out.expectVersion = argv[++i];
+    else if (argv[i] === '--base-url') out.baseUrl = argv[++i];
+    else if (argv[i] === '--json') out.json = true;
+  }
+  return out;
+}
+
+// Minimal electron-builder-feed parser. We only need `version:` and the asset
+// filenames (top-level `path:` plus each `- url:` under `files:`). Avoiding a
+// YAML dependency keeps this runnable on a bare CI node with no install step.
+function parseFeed(text) {
+  const version = (text.match(/^version:\s*(.+)$/m) || [])[1];
+  const assets = new Set();
+  const topPath = (text.match(/^path:\s*(.+)$/m) || [])[1];
+  if (topPath) assets.add(topPath.trim());
+  const urlRe = /^\s*-?\s*url:\s*(.+)$/gm;
+  let m;
+  while ((m = urlRe.exec(text)) !== null) assets.add(m[1].trim());
+  return { version: version ? version.trim() : null, assets: [...assets] };
+}
+
+function headOk(url) {
+  return new Promise((resolve) => {
+    const req = https.request(url, { method: 'HEAD' }, (res) => {
+      // GitHub release assets 302 to a signed CDN URL; follow one hop.
+      if (res.statusCode >= 300 && res.statusCode < 400 && res.headers.location) {
+        headOk(res.headers.location).then(resolve);
+      } else {
+        resolve(res.statusCode === 200);
+      }
+    });
+    req.on('error', () => resolve(false));
+    req.setTimeout(15000, () => { req.destroy(); resolve(false); });
+    req.end();
+  });
+}
+
+function fail(msg, json) {
+  if (json) process.stdout.write(JSON.stringify({ ok: false, error: msg }) + '\n');
+  else process.stderr.write(`BLOCKED: ${msg}\n`);
+  process.exit(1);
+}
+
+async function main() {
+  const args = parseArgs(process.argv.slice(2));
+  if (!args.dir) fail('--dir <artifacts-dir> is required', args.json);
+
+  const feeds = {};
+  for (const name of FEEDS) {
+    const p = path.join(args.dir, name);
+    if (!fs.existsSync(p)) fail(`missing feed: ${name} (one platform would be stranded on the old build)`, args.json);
+    feeds[name] = parseFeed(fs.readFileSync(p, 'utf8'));
+    if (!feeds[name].version) fail(`${name} has no version: field`, args.json);
+  }
+
+  const versions = FEEDS.map((n) => feeds[n].version);
+  if (new Set(versions).size !== 1) {
+    fail(`version mismatch across feeds: ${FEEDS.map((n) => `${n}=${feeds[n].version}`).join(', ')}`, args.json);
+  }
+  const releaseVersion = versions[0];
+
+  if (args.expectVersion) {
+    const want = args.expectVersion.replace(/^v/, '');
+    if (releaseVersion !== want) fail(`feeds say ${releaseVersion} but expected ${want}`, args.json);
+  }
+
+  if (args.baseUrl) {
+    const base = args.baseUrl.replace(/\/+$/, '');
+    for (const name of FEEDS) {
+      // The .yml itself must resolve, plus every asset it points at.
+      const toCheck = [name, ...feeds[name].assets];
+      for (const asset of toCheck) {
+        const url = `${base}/${asset}`;
+        // eslint-disable-next-line no-await-in-loop
+        const ok = await headOk(url);
+        if (!ok) fail(`asset does not resolve (HEAD != 200): ${url}`, args.json);
+      }
+    }
+  }
+
+  const result = { ok: true, version: releaseVersion, feeds: FEEDS, checkedUrls: !!args.baseUrl };
+  if (args.json) process.stdout.write(JSON.stringify(result) + '\n');
+  else {
+    process.stdout.write(`\nPROMOTABLE: both feeds present, version ${releaseVersion} agrees`);
+    process.stdout.write(args.baseUrl ? ', all assets resolve.\n\n' : ' (URL check skipped; pass --base-url to enable).\n\n');
+  }
+}
+
+main();
diff --git a/scripts/release/check-shell-token.sh b/scripts/release/check-shell-token.sh
new file mode 100755
index 00000000..158d6845
--- /dev/null
+++ b/scripts/release/check-shell-token.sh
@@ -0,0 +1,20 @@
+#!/bin/bash
+# The shell is the public repo every installed updater polls; a build repo's own workflow token cannot write to it.
+set -euo pipefail
+
+SHELL_REPO="${RELEASE_SHELL_REPO:-openswarm-ai/openswarm}"
+
+if [ -z "${GH_TOKEN:-}" ]; then
+    echo "RELEASE_SHELL_TOKEN is not set: this run cannot publish into $SHELL_REPO" >&2
+    exit 1
+fi
+if ! gh api "repos/$SHELL_REPO" --jq '.full_name' >/dev/null; then
+    echo "the release token cannot read $SHELL_REPO" >&2
+    exit 1
+fi
+if [ "$(gh api "repos/$SHELL_REPO" --jq '.permissions.push')" != "true" ]; then
+    echo "the release token cannot write to $SHELL_REPO, so the release would land nowhere" >&2
+    exit 1
+fi
+gh release list --repo "$SHELL_REPO" --limit 1 >/dev/null
+echo "release shell $SHELL_REPO is reachable with write access"
diff --git a/scripts/release/sync-shell.sh b/scripts/release/sync-shell.sh
new file mode 100755
index 00000000..970617dd
--- /dev/null
+++ b/scripts/release/sync-shell.sh
@@ -0,0 +1,43 @@
+#!/bin/bash
+# Publishes release-shell/ as the only content of the public shell's main. Tags and releases are never touched:
+# every installed updater and every download link reads them from this repo, and a deleted tag takes its release with it.
+set -euo pipefail
+
+SHELL_REPO="${RELEASE_SHELL_REPO:-openswarm-ai/openswarm}"
+ROOT="$(cd "$(dirname "$0")/../.." && pwd)"
+MODE="${1:---dry-run}"
+case "$MODE" in
+    --dry-run|--apply|--apply-and-prune) ;;
+    *) echo "usage: sync-shell.sh [--dry-run|--apply|--apply-and-prune]" >&2; exit 2 ;;
+esac
+
+cmp -s "$ROOT/scripts/release/verify-release.js" "$ROOT/release-shell/scripts/release/verify-release.js" \
+    || { echo "release-shell/scripts/release/verify-release.js drifted from scripts/release/verify-release.js" >&2; exit 1; }
+cmp -s "$ROOT/electron/build/icon.ico" "$ROOT/release-shell/electron/build/icon.ico" \
+    || { echo "release-shell/electron/build/icon.ico drifted from electron/build/icon.ico" >&2; exit 1; }
+
+WORK="$(mktemp -d)"
+trap 'rm -rf "$WORK"' EXIT
+git init -q "$WORK"
+cp -R "$ROOT/release-shell/." "$WORK/"
+(cd "$WORK" && git add -A && git -c user.name=openswarm -c user.email=releases@openswarm.com commit -q -m "releases shell, synced $(date -u +%Y-%m-%d)")
+
+echo "== $SHELL_REPO main would carry:"
+(cd "$WORK" && git ls-files | sed 's/^/   /')
+others="$(gh api "repos/$SHELL_REPO/branches?per_page=100" --paginate --jq '.[].name' | grep -vx main || true)"
+echo "== branches on $SHELL_REPO other than main: $(printf '%s\n' "$others" | grep -c . || true)"
+echo "== tags on $SHELL_REPO (kept): $(gh api "repos/$SHELL_REPO/tags?per_page=100" --paginate --jq '.[].name' | grep -c . || true)"
+
+if [ "$MODE" = "--dry-run" ]; then
+    echo "dry run: nothing pushed, nothing deleted"
+    exit 0
+fi
+
+(cd "$WORK" && git push --force "https://github.com/$SHELL_REPO.git" HEAD:refs/heads/main)
+echo "pushed release-shell/ as $SHELL_REPO main"
+
+if [ "$MODE" = "--apply-and-prune" ]; then
+    for b in $others; do
+        gh api -X DELETE "repos/$SHELL_REPO/git/refs/heads/$b" >/dev/null && echo "deleted branch $b"
+    done
+fi