diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 6a40678..9a384da 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -40,12 +40,15 @@ jobs:
       - uses: actions/checkout@v7
         with:
           submodules: recursive
+          fetch-depth: 0
       - uses: actions/setup-node@v6
         with:
           node-version: 22
           cache: npm
       - name: Verify release version
         run: node scripts/verify-release-version.js
+      - name: Verify Companion release identity
+        run: node scripts/verify-companion-release.js
       - uses: dtolnay/rust-toolchain@stable
         with:
           targets: ${{ matrix.target }}
diff --git a/RELEASE.md b/RELEASE.md
index f4b8954..a99b8b9 100644
--- a/RELEASE.md
+++ b/RELEASE.md
@@ -65,6 +65,11 @@ pass. A `workflow_dispatch` on a `v*` tag also publishes when its
 release-certification inputs; clean-machine QA remains a release-owner gate
 before pushing the tag.
 
+For paired releases, publish and verify the Companion release first. The
+desktop release workflow requires `Extensions/Browser` to be at a clean commit
+whose exact tag matches both the Companion `package.json` and `manifest.json`
+versions before building desktop packages.
+
 ## Automated release builds
 
 Push a version tag to build and verify native artifacts:
diff --git a/scripts/verify-companion-release.js b/scripts/verify-companion-release.js
new file mode 100644
index 0000000..4b607f5
--- /dev/null
+++ b/scripts/verify-companion-release.js
@@ -0,0 +1,81 @@
+#!/usr/bin/env node
+import fs from 'node:fs';
+import path from 'node:path';
+import { execFileSync } from 'node:child_process';
+import { fileURLToPath } from 'node:url';
+
+const scriptDirectory = path.dirname(fileURLToPath(import.meta.url));
+const defaultRepositoryRoot = path.resolve(scriptDirectory, '..');
+const SEMVER = /^\d+\.\d+\.\d+(?:-[0-9A-Za-z.-]+)?(?:\+[0-9A-Za-z.-]+)?$/;
+
+function readJson(file) {
+  return JSON.parse(fs.readFileSync(file, 'utf8'));
+}
+
+function exactVersionTag(extensionRoot, expectedTag) {
+  try {
+    const tags = execFileSync(
+      'git',
+      ['-C', extensionRoot, 'tag', '--points-at', 'HEAD', '--list', '--', expectedTag],
+      { encoding: 'utf8', stdio: ['ignore', 'pipe', 'ignore'] }
+    )
+      .split(/\r?\n/)
+      .map(tag => tag.trim())
+      .find(tag => tag === expectedTag);
+    return tags || null;
+  } catch {
+    return null;
+  }
+}
+
+export function verifyCompanionRelease({
+  repositoryRoot = defaultRepositoryRoot,
+  resolveExactTag = exactVersionTag,
+} = {}) {
+  const extensionRoot = path.join(repositoryRoot, 'Extensions', 'Browser');
+  const packagePath = path.join(extensionRoot, 'package.json');
+  const manifestPath = path.join(extensionRoot, 'manifest.json');
+
+  if (!fs.existsSync(packagePath) || !fs.existsSync(manifestPath)) {
+    throw new Error('Companion package.json and manifest.json must both exist.');
+  }
+
+  const packageVersion = readJson(packagePath).version;
+  const manifestVersion = readJson(manifestPath).version;
+  if (!packageVersion || packageVersion !== manifestVersion) {
+    throw new Error(
+      `Companion versions do not agree: package.json=${packageVersion || 'missing'}, ` +
+      `manifest.json=${manifestVersion || 'missing'}.`
+    );
+  }
+  if (typeof packageVersion !== 'string' || !SEMVER.test(packageVersion)) {
+    throw new Error(`Companion version ${String(packageVersion)} is not a valid semantic version.`);
+  }
+
+  const expectedTag = `v${packageVersion}`;
+  const tag = resolveExactTag(extensionRoot, expectedTag);
+  if (!tag) {
+    throw new Error(
+      `Companion HEAD is not exactly tagged ${expectedTag}; publish the Companion release first.`
+    );
+  }
+  if (tag !== expectedTag) {
+    throw new Error(`Companion HEAD tag ${tag} does not match ${expectedTag}.`);
+  }
+
+  return { tag, version: packageVersion };
+}
+
+function main() {
+  try {
+    const { tag, version } = verifyCompanionRelease();
+    console.log(`Companion release ${version} matches exact tag ${tag}.`);
+  } catch (error) {
+    console.error(error instanceof Error ? error.message : String(error));
+    process.exitCode = 1;
+  }
+}
+
+if (path.resolve(process.argv[1] || '') === fileURLToPath(import.meta.url)) {
+  main();
+}
diff --git a/scripts/verify-companion-release.node-test.js b/scripts/verify-companion-release.node-test.js
new file mode 100644
index 0000000..2799301
--- /dev/null
+++ b/scripts/verify-companion-release.node-test.js
@@ -0,0 +1,97 @@
+import assert from 'node:assert/strict';
+import fs from 'node:fs';
+import os from 'node:os';
+import path from 'node:path';
+import test from 'node:test';
+import { verifyCompanionRelease } from './verify-companion-release.js';
+
+function createFixture(packageVersion, manifestVersion) {
+  const root = fs.mkdtempSync(path.join(os.tmpdir(), 'firelink-companion-release-'));
+  const extensionRoot = path.join(root, 'Extensions', 'Browser');
+  fs.mkdirSync(extensionRoot, { recursive: true });
+  fs.writeFileSync(
+    path.join(extensionRoot, 'package.json'),
+    `${JSON.stringify({ version: packageVersion }, null, 2)}\n`
+  );
+  fs.writeFileSync(
+    path.join(extensionRoot, 'manifest.json'),
+    `${JSON.stringify({ version: manifestVersion }, null, 2)}\n`
+  );
+  return root;
+}
+
+test('accepts matching Companion metadata and exact release tag', () => {
+  const root = createFixture('2.0.7', '2.0.7');
+  try {
+    let resolvedExpectedTag;
+    assert.deepEqual(
+      verifyCompanionRelease({
+        repositoryRoot: root,
+        resolveExactTag: (_extensionRoot, expectedTag) => {
+          resolvedExpectedTag = expectedTag;
+          return 'v2.0.7';
+        },
+      }),
+      { tag: 'v2.0.7', version: '2.0.7' }
+    );
+    assert.equal(resolvedExpectedTag, 'v2.0.7');
+  } finally {
+    fs.rmSync(root, { recursive: true, force: true });
+  }
+});
+
+test('rejects mismatched Companion package and manifest versions', () => {
+  const root = createFixture('2.0.7', '2.0.6');
+  try {
+    assert.throws(
+      () => verifyCompanionRelease({ repositoryRoot: root, resolveExactTag: () => 'v2.0.7' }),
+      /versions do not agree/
+    );
+  } finally {
+    fs.rmSync(root, { recursive: true, force: true });
+  }
+});
+
+test('rejects a malformed Companion semantic version before tag lookup', () => {
+  const root = createFixture('--contains=HEAD', '--contains=HEAD');
+  let tagLookupCalled = false;
+  try {
+    assert.throws(
+      () => verifyCompanionRelease({
+        repositoryRoot: root,
+        resolveExactTag: () => {
+          tagLookupCalled = true;
+          return 'v--contains=HEAD';
+        },
+      }),
+      /not a valid semantic version/
+    );
+    assert.equal(tagLookupCalled, false);
+  } finally {
+    fs.rmSync(root, { recursive: true, force: true });
+  }
+});
+
+test('rejects an untagged Companion commit', () => {
+  const root = createFixture('2.0.7', '2.0.7');
+  try {
+    assert.throws(
+      () => verifyCompanionRelease({ repositoryRoot: root, resolveExactTag: () => null }),
+      /not exactly tagged v2.0.7/
+    );
+  } finally {
+    fs.rmSync(root, { recursive: true, force: true });
+  }
+});
+
+test('rejects a Companion tag for another version', () => {
+  const root = createFixture('2.0.7', '2.0.7');
+  try {
+    assert.throws(
+      () => verifyCompanionRelease({ repositoryRoot: root, resolveExactTag: () => 'v2.0.6' }),
+      /does not match v2.0.7/
+    );
+  } finally {
+    fs.rmSync(root, { recursive: true, force: true });
+  }
+});