diff --git a/.github/scripts/check-changeset-coverage.mjs b/.github/scripts/check-changeset-coverage.mjs
index 8d2a208..ceee21e 100644
--- a/.github/scripts/check-changeset-coverage.mjs
+++ b/.github/scripts/check-changeset-coverage.mjs
@@ -28,6 +28,55 @@ for (const entry of workspaceListing) {
 }
 const knownNames = new Set(Object.values(dirToName));
 
+// Optional per-repo hygiene config (.changeset/hygiene.json, all keys optional):
+//   {
+//     "releasePackagePaths": { "packages/rrweb/": "posthog-js" },
+//     "transitiveReExports": { "<source-pkg>": ["<re-exporter>"] }
+//   }
+//
+// releasePackagePaths replaces workspace ownership for files under a repo-relative
+// directory with the package that ships them. Targets must be known workspace
+// packages. Trailing slashes are optional; the most specific directory wins.
+// This makes bundled sources require only the shipping package's changeset,
+// without incorrectly reporting that changeset as extra.
+//
+// transitiveReExports allows a re-exporter's changeset when its source package
+// has both source changes and a changeset (e.g. Gradle api(project(":x"))).
+let transitiveReExports = {};
+let releasePackagePaths = [];
+const hygieneConfigPath = '.changeset/hygiene.json';
+if (existsSync(hygieneConfigPath)) {
+    try {
+        const cfg = JSON.parse(readFileSync(hygieneConfigPath, 'utf8'));
+        if (cfg.transitiveReExports && typeof cfg.transitiveReExports === 'object') {
+            transitiveReExports = cfg.transitiveReExports;
+        }
+        if (
+            cfg.releasePackagePaths &&
+            typeof cfg.releasePackagePaths === 'object' &&
+            !Array.isArray(cfg.releasePackagePaths)
+        ) {
+            releasePackagePaths = Object.entries(cfg.releasePackagePaths)
+                .map(([dir, name]) => [dir.replace(/\/$/, ''), name])
+                .filter(([dir, name]) => {
+                    if (
+                        dir.split('/').some((part) => !part || part === '.' || part === '..') ||
+                        !knownNames.has(name)
+                    ) {
+                        process.stderr.write(
+                            `Ignoring invalid releasePackagePaths entry in ${hygieneConfigPath}: ${dir} -> ${name}\n`,
+                        );
+                        return false;
+                    }
+                    return true;
+                })
+                .sort(([a], [b]) => b.length - a.length);
+        }
+    } catch (e) {
+        process.stderr.write(`Could not parse ${hygieneConfigPath}: ${e.message}\n`);
+    }
+}
+
 // 2. Diff vs base.
 const mergeBase = sh(`git merge-base origin/${baseRef} HEAD`);
 const changedFiles = sh(`git diff --name-only ${mergeBase}...HEAD`).split('\n').filter(Boolean);
@@ -38,6 +87,13 @@ const affected = new Set();
 for (const file of changedFiles) {
     if (file.startsWith('.changeset/')) continue;
     if (ignoreSuffixes.some((s) => file.endsWith(s))) continue;
+    const releasePackage = releasePackagePaths.find(
+        ([dir]) => file === dir || file.startsWith(dir + '/'),
+    );
+    if (releasePackage) {
+        affected.add(releasePackage[1]);
+        continue;
+    }
     for (const [dir, name] of Object.entries(dirToName)) {
         if (file === dir || file.startsWith(dir + '/')) {
             affected.add(name);
@@ -53,34 +109,6 @@ const changesetFiles = sh(
     .split('\n')
     .filter((f) => f.endsWith('.md') && !f.endsWith('README.md'));
 
-// 4.5. Optional per-repo hygiene config for transitive re-exports.
-//
-// Schema (.changeset/hygiene.json, all keys optional):
-//   {
-//     "transitiveReExports": {
-//       "<source-pkg>": ["<re-exporter-1>", "<re-exporter-2>"]
-//     }
-//   }
-//
-// When <source-pkg> has source changes AND is declared in a changeset on this
-// PR, declaring any of its re-exporters is treated as legitimate even if no
-// source files in that re-exporter changed. Use for cases the workspace graph
-// can't see — e.g. Gradle `api(project(":x"))` re-exports where a downstream
-// artifact must be republished to deliver an upstream core change to its own
-// consumers.
-let transitiveReExports = {};
-const hygieneConfigPath = '.changeset/hygiene.json';
-if (existsSync(hygieneConfigPath)) {
-    try {
-        const cfg = JSON.parse(readFileSync(hygieneConfigPath, 'utf8'));
-        if (cfg.transitiveReExports && typeof cfg.transitiveReExports === 'object') {
-            transitiveReExports = cfg.transitiveReExports;
-        }
-    } catch (e) {
-        process.stderr.write(`Could not parse ${hygieneConfigPath}: ${e.message}\n`);
-    }
-}
-
 const writeOutput = (body) => {
     if (!body) {
         process.stdout.write('body=\n');
diff --git a/.github/scripts/check-changeset-coverage.test.mjs b/.github/scripts/check-changeset-coverage.test.mjs
new file mode 100644
index 0000000..9798ed2
--- /dev/null
+++ b/.github/scripts/check-changeset-coverage.test.mjs
@@ -0,0 +1,186 @@
+import assert from 'node:assert/strict';
+import { execFileSync } from 'node:child_process';
+import { mkdtempSync, mkdirSync, realpathSync, rmSync, writeFileSync } from 'node:fs';
+import { tmpdir } from 'node:os';
+import { dirname, join } from 'node:path';
+import { fileURLToPath } from 'node:url';
+import test from 'node:test';
+
+const script = fileURLToPath(new URL('./check-changeset-coverage.mjs', import.meta.url));
+const packages = {
+    'packages/browser': 'posthog-js',
+    'packages/rrweb/rrweb': '@posthog/rrweb',
+    'packages/rrweb/types': '@posthog/rrweb-types',
+    'packages/rrweb-extra': 'rrweb-extra',
+    'packages/node': 'posthog-node',
+};
+const mapping = { releasePackagePaths: { 'packages/rrweb/': 'posthog-js' } };
+
+function report(t, { files = [], declared = [], config } = {}) {
+    const cwd = realpathSync(mkdtempSync(join(tmpdir(), 'changeset-hygiene-')));
+    t.after(() => rmSync(cwd, { recursive: true, force: true }));
+    function write(path, content) {
+        mkdirSync(dirname(join(cwd, path)), { recursive: true });
+        writeFileSync(join(cwd, path), content);
+    }
+    const git = (...args) => execFileSync('git', args, { cwd, stdio: 'pipe' });
+    git('init', '-b', 'main');
+    git('config', 'user.email', 'test@example.com');
+    git('config', 'user.name', 'Test');
+    git('config', 'commit.gpgsign', 'false');
+    git('config', 'core.hooksPath', '/dev/null');
+    // Stub only workspace discovery. Exercise the real script, git diff and frontmatter parser.
+    write(
+        'bin/pnpm',
+        `#!/bin/sh\nprintf '%s\\n' '${JSON.stringify(
+            Object.entries(packages).map(([path, name]) => ({ path: join(cwd, path), name })),
+        )}'\n`,
+    );
+    execFileSync('chmod', ['+x', join(cwd, 'bin/pnpm')]);
+    if (config) write('.changeset/hygiene.json', JSON.stringify(config));
+    git('add', '.');
+    git('commit', '-m', 'base');
+    git('update-ref', 'refs/remotes/origin/main', 'HEAD');
+    for (const file of files) write(file, 'changed\n');
+    if (declared.length) {
+        write(
+            '.changeset/change.md',
+            `---\n${declared.map((n) => `'${n}': patch`).join('\n')}\n---\n\nChange\n`,
+        );
+    }
+    git('add', '.');
+    git('commit', '--allow-empty', '-m', 'change');
+    return execFileSync(process.execPath, [script], {
+        cwd,
+        encoding: 'utf8',
+        env: { ...process.env, BASE_REF: 'main', PATH: `${cwd}/bin:${process.env.PATH}` },
+    });
+}
+
+test('rrweb-only changes are covered by a browser changeset', (t) => {
+    assert.equal(
+        report(t, {
+            files: ['packages/rrweb/rrweb/src/index.ts', 'packages/rrweb/types/src/index.ts'],
+            declared: ['posthog-js'],
+            config: mapping,
+        }),
+        'body=\n',
+    );
+});
+
+test('rrweb changes without a changeset request only the browser package', (t) => {
+    const body = report(t, { files: ['packages/rrweb/rrweb/src/index.ts'], config: mapping });
+    assert.match(body, /`posthog-js` is modified but this PR has no changeset/);
+    assert.doesNotMatch(body, /@posthog\/rrweb/);
+});
+
+test('an rrweb changeset does not satisfy the browser release requirement', (t) => {
+    const body = report(t, {
+        files: ['packages/rrweb/rrweb/src/index.ts'],
+        declared: ['@posthog/rrweb'],
+        config: mapping,
+    });
+    assert.match(body, /"posthog-js": patch/);
+    assert.match(
+        body,
+        /\*\*Declared in a changeset but no source files modified:\*\*\n- `@posthog\/rrweb`/,
+    );
+});
+
+test('unmapped packages still need their own changesets', (t) => {
+    const body = report(t, {
+        files: ['packages/rrweb/rrweb/src/index.ts', 'packages/node/src/index.ts'],
+        declared: ['posthog-js'],
+        config: mapping,
+    });
+    assert.match(body, /`posthog-node` is modified but not declared/);
+    assert.doesNotMatch(body, /@posthog\/rrweb/);
+});
+
+test('path matching respects directory boundaries', (t) => {
+    const body = report(t, { files: ['packages/rrweb-extra/src/index.ts'], config: mapping });
+    assert.match(body, /`rrweb-extra` is modified/);
+    assert.doesNotMatch(body, /posthog-js/);
+});
+
+test('the most specific mapping wins, with or without trailing slashes', (t) => {
+    assert.equal(
+        report(t, {
+            files: ['packages/rrweb/rrweb/src/index.ts', 'packages/rrweb/types/src/index.ts'],
+            declared: ['posthog-js', 'posthog-node'],
+            config: {
+                releasePackagePaths: {
+                    'packages/rrweb': 'posthog-js',
+                    'packages/rrweb/types/': 'posthog-node',
+                },
+            },
+        }),
+        'body=\n',
+    );
+});
+
+test('changelog and manifest changes remain ignored under mapped paths', (t) => {
+    assert.equal(
+        report(t, {
+            files: ['packages/rrweb/rrweb/CHANGELOG.md', 'packages/rrweb/types/package.json'],
+            config: mapping,
+        }),
+        'body=\n',
+    );
+});
+
+test('no config preserves normal workspace coverage', (t) => {
+    assert.equal(
+        report(t, {
+            files: ['packages/rrweb/rrweb/src/index.ts'],
+            declared: ['@posthog/rrweb'],
+        }),
+        'body=\n',
+    );
+});
+
+test('transitive re-export config still works', (t) => {
+    assert.equal(
+        report(t, {
+            files: ['packages/node/src/index.ts'],
+            declared: ['posthog-node', 'posthog-js'],
+            config: { transitiveReExports: { 'posthog-node': ['posthog-js'] } },
+        }),
+        'body=\n',
+    );
+});
+
+test('browser and bundled source changes share one changeset', (t) => {
+    assert.equal(
+        report(t, {
+            files: ['packages/browser/src/index.ts', 'packages/rrweb/rrweb/src/index.ts'],
+            declared: ['posthog-js'],
+            config: mapping,
+        }),
+        'body=\n',
+    );
+});
+
+for (const [path, target] of [
+    ['packages/rrweb/', 'typo'],
+    ['', 'posthog-js'],
+    ['../packages/rrweb', 'posthog-js'],
+]) {
+    test(`invalid mapping ${path} -> ${target} keeps workspace coverage`, (t) => {
+        assert.equal(
+            report(t, {
+                files: ['packages/rrweb/rrweb/src/index.ts'],
+                declared: ['@posthog/rrweb'],
+                config: { releasePackagePaths: { [path]: target } },
+            }),
+            'body=\n',
+        );
+    });
+}
+
+test('browser changesets without source changes are still reported as extra', (t) => {
+    assert.match(
+        report(t, { declared: ['posthog-js'], config: mapping }),
+        /Changeset declares `posthog-js` but no source files in that package changed/,
+    );
+});
diff --git a/.github/workflows/changeset-hygiene-tests.yml b/.github/workflows/changeset-hygiene-tests.yml
new file mode 100644
index 0000000..1b51748
--- /dev/null
+++ b/.github/workflows/changeset-hygiene-tests.yml
@@ -0,0 +1,24 @@
+name: Changeset hygiene tests
+
+on:
+    pull_request:
+    merge_group:
+
+permissions:
+    contents: read
+
+jobs:
+    test:
+        runs-on: ubuntu-latest
+        timeout-minutes: 5
+        steps:
+            - name: Checkout
+              uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+
+            - name: Setup Node
+              uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6.4.0
+              with:
+                  node-version: '22'
+
+            - name: Test changeset coverage
+              run: node --test .github/scripts/check-changeset-coverage.test.mjs
diff --git a/AGENTS.md b/AGENTS.md
index ab7d055..4e1cfe6 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -18,7 +18,13 @@ There is no build step and no app. Changes are config (YAML workflows, semgrep r
 
 ## Testing
 
-No general test suite. The one locally runnable thing is the semgrep rule tests:
+No general test suite. Run the changeset hygiene script tests with:
+
+```bash
+node --test .github/scripts/check-changeset-coverage.test.mjs
+```
+
+The semgrep rule tests run with:
 
 ```bash
 semgrep --test .semgrep/