diff --git a/.github/scripts/ci-policy.mjs b/.github/scripts/ci-policy.mjs
index b7ba92331..e4a53e88e 100644
--- a/.github/scripts/ci-policy.mjs
+++ b/.github/scripts/ci-policy.mjs
@@ -22,7 +22,7 @@ export function isDocumentationPath(file) {
   if (cppPath.test(file) || /^CMake(?:Lists\.txt|(?:User)?Presets\.json|Cache\.txt)$/i.test(name) || /\.cmake$/i.test(file) ||
       dependencyName.test(name) || file.split('/').includes('.github') || /^action\.ya?ml$/i.test(name) ||
       /^\.clang-(?:format|tidy)$/.test(name)) return false;
-  if (file === 'README.md' || file === 'README_CN.md' || pluginIndexPaths.has(file) || testGuidePaths.has(file)) return true;
+  if (file === 'AGENTS.md' || file === 'README.md' || file === 'README_CN.md' || pluginIndexPaths.has(file) || testGuidePaths.has(file)) return true;
   return file.startsWith('docs/') && (docPath.test(file) || name === 'LICENSE' || name === '.gitignore');
 }
 
@@ -98,7 +98,7 @@ export function selectScope({ eventName, files, site, enumerationFailed = false
   const scopedEvent = eventName === 'pull_request' || eventName === 'merge_group';
   const docsOnly = scopedEvent && nonempty && site.available && paths.every(isDocumentationPath);
   const readme = paths.some(file => file === 'README.md' || file === 'README_CN.md');
-  const docsTouched = readme || paths.some(file => file.startsWith('docs/') || pluginIndexPaths.has(file) || testGuidePaths.has(file));
+  const docsTouched = readme || paths.some(file => file === 'AGENTS.md' || file.startsWith('docs/') || pluginIndexPaths.has(file) || testGuidePaths.has(file));
   const ciTouched = paths.some(file => file.startsWith('.github/') || file.startsWith('tests/ci/'));
   const siteReferenced = site.present || paths.some(file => file.startsWith('docs/site/'));
   const docs = siteReferenced && (eventName !== 'pull_request' || !known || docsTouched || ciTouched);
diff --git a/docs/project/contributing.md b/docs/project/contributing.md
index 157c15b20..297512f87 100644
--- a/docs/project/contributing.md
+++ b/docs/project/contributing.md
@@ -15,6 +15,19 @@ npm run check --prefix docs/site
 The site provides language switching, search, code highlighting and plain Markdown endpoints for AI readers. Pull requests run the documentation checks without publishing. After a change is merged into `main`, the documentation workflow builds and publishes GitHub Pages; maintainers can also trigger it manually. Node.js 22.12+ is needed for the documentation build; it is not needed to compile ark or its C++ tests.
 
 
+## CI documentation scope
+
+The exact root `AGENTS.md` file is documentation. When the changed range is known,
+nonempty and confined to recognized documentation, and the Nimbus site is available,
+both source PRs and merge-group candidates require the documentation checks and
+`CI - required`, while native jobs are explicitly skipped. Nimbus checks the site;
+root README link checks run only when a root README changes.
+
+Nested unknown `AGENTS.md` paths, similarly named code, mixed source changes,
+unavailable ranges or an unavailable site retain native checks. Manual runs keep
+the full native matrix. Changes to the CI policy itself still require native
+acceptance; this documentation exception does not change that requirement.
+
 ## CI dependency archive cache
 
 CI restores vcpkg package archives from the runner temporary directory with
diff --git a/docs/project/contributing_CN.md b/docs/project/contributing_CN.md
index 611db3369..efd4752f8 100644
--- a/docs/project/contributing_CN.md
+++ b/docs/project/contributing_CN.md
@@ -15,6 +15,16 @@ npm run check --prefix docs/site
 站点提供语言切换、搜索、代码高亮，以及供 AI 阅读的纯 Markdown 接口。PR 只运行文档检查，不发布站点。变更合并到 `main` 后，文档工作流构建并发布 GitHub Pages；维护者也可手动触发。文档构建需要 Node.js 22.12+；编译 ark 与 C++ 测试不需要 Node.js。
 
 
+## CI 文档范围
+
+根目录的精确文件 `AGENTS.md` 归为文档。改动范围已知且非空、仅包含已识别的文档，
+并且 Nimbus 文档站可用时，源分支 PR 与合并候选均要求文档检查和 `CI - required`，
+原生任务明确跳过。Nimbus 检查文档站；只有根 README 变化时才检查其链接。
+
+嵌套的未知 `AGENTS.md` 路径、名称相近的代码、混合源码变更、范围不可用或文档站不可用时，
+仍保留原生检查。手动运行保留完整原生矩阵。CI 策略本身的变更仍须完成原生验收，
+这项文档例外不会改变该要求。
+
 ## CI 依赖包归档缓存
 
 CI 使用 `actions/cache` 恢复执行机临时目录中的 vcpkg 包归档。
diff --git a/tests/ci/README.md b/tests/ci/README.md
index fa7d1423f..60a681737 100644
--- a/tests/ci/README.md
+++ b/tests/ci/README.md
@@ -96,6 +96,14 @@ their own refs. Independent groups do not enforce PR creation order. The require
 gate still rejects failed, cancelled or missing results. Manual cancellation can
 still prevent the `always()` summary from completing. See [GitHub concurrency rules](https://docs.github.com/en/actions/reference/workflows-and-actions/workflow-syntax#concurrency).
 
+The exact root `AGENTS.md` path also qualifies as documentation. A known,
+nonempty range confined to that file and other recognized documentation selects
+Nimbus and the final required gate on both PRs and merge-group candidates, with
+native jobs explicitly skipped when the site is available. This does not extend
+the root README link check or exempt nested `AGENTS.md` files, similarly named
+code, mixed source changes or uncertain ranges. Manual runs retain the full
+native matrix. This CI policy change itself still requires native acceptance.
+
 Within `src/`, only the exact plugin index paths `src/plugins/README.md` and
 `src/plugins/README_CN.md` additionally qualify as documentation. Changes confined
 to these indexes select the Nimbus check on PRs and documentation-only queue
diff --git a/tests/ci/README_CN.md b/tests/ci/README_CN.md
index f78798d0f..9ee8db541 100644
--- a/tests/ci/README_CN.md
+++ b/tests/ci/README_CN.md
@@ -66,6 +66,12 @@ README 徽章展示合并候选的工作流状态。
 required gate 仍拒绝失败、取消或缺失的结果。手动取消仍可能使 `always()` 汇总无法完成。
 详见 [GitHub 并发规则](https://docs.github.com/en/actions/reference/workflows-and-actions/workflow-syntax#concurrency)。
 
+根目录的精确路径 `AGENTS.md` 也归为文档。范围已知且非空、文档站可用时，
+仅修改该文件和其他已识别文档的 PR 与合并候选均要求 Nimbus 检查和最终必需门禁，
+并明确跳过原生任务。这不会扩展根 README 链接检查，也不会豁免嵌套的 `AGENTS.md`、
+名称相近的代码、混合源码变更或不确定范围。手动运行仍保留完整原生矩阵。
+本次 CI 策略变更自身仍须完成原生验收。
+
 `src/` 下仅将两个精确的插件索引路径 `src/plugins/README.md` 与 `src/plugins/README_CN.md` 归为文档。
 文档站可用时，只修改这两个索引的 PR 与纯文档合并候选会选择 Nimbus 检查。
 这不会将根 README 链接检查扩展到插件索引；Nimbus 验证生成的文档站，不直接检查索引文件。
diff --git a/tests/ci/module-validation.test.mjs b/tests/ci/module-validation.test.mjs
index fe96edd87..1fa8aaf95 100644
--- a/tests/ci/module-validation.test.mjs
+++ b/tests/ci/module-validation.test.mjs
@@ -30,7 +30,8 @@ test('actual workflow output bindings provide complete plans to the required gat
   const outputs = [...jobBlock('scope').matchAll(/^      (\w+): \$\{\{ steps\.scope\.outputs\.(\w+) \}\}$/gm)];
   assert.ok(outputs.length > 0);
   for (const scope of [plan(['tests/network/rudp.cpp']), plan(['include/ark/core/module.hpp']),
-    plan(['README.md']), plan(['tests/database/redis_service.cpp'], 'merge_group'),
+    plan(['README.md']), plan(['AGENTS.md']), plan(['AGENTS.md'], 'merge_group'),
+    plan(['tests/database/redis_service.cpp'], 'merge_group'),
     plan(['README.md'], 'merge_group'), plan([], 'workflow_dispatch'), plan([], 'pull_request')]) {
     const needs = results(scope);
     needs.scope.outputs = Object.fromEntries(outputs.map(([, name, source]) => [name, String(scope[source])]));
@@ -113,7 +114,7 @@ test('public core headers, build/dependency/CI inputs and unknown paths retain e
     '3rdparty/spdlog', 'ports/asio/portfile.cmake', '.github/workflows/ci.yml',
     'config/timers.app.toml', 'resources/excel/item.xlsx', 'resources/photon/proto/protocol.proto',
     'tools/gen-config.sh', 'deployment/scripts/run.sh',
-    '.github/scripts/ci-policy.mjs', 'tests/ci/module-validation.test.mjs', 'AGENTS.md', '.clang-format',
+    '.github/scripts/ci-policy.mjs', 'tests/ci/module-validation.test.mjs', 'src/AGENTS.md', '.clang-format',
     'application/unknown.bin', 'application/build.cmake', 'applications/main.cpp', 'src/app/main.cpp',
     'src/plugins/new_plugin/new_module.cpp', 'src/plugins/net/unknown.bin', 'scripts/new-check.sh',
     'docs/example.cpp', 'docs/site/package-lock.json', 'docs/unknown.bin', 'LICENSE']) {
diff --git a/tests/ci/policy.test.mjs b/tests/ci/policy.test.mjs
index 2a0810544..46c3bdbc8 100644
--- a/tests/ci/policy.test.mjs
+++ b/tests/ci/policy.test.mjs
@@ -64,6 +64,99 @@ test('only recognized documentation paths qualify for the lightweight plan', ()
   assert.equal(decision(['README.md', 'docs/guide.md']).docs_check, true);
 });
 
+test('root AGENTS.md requires documentation and the final gate without native work at both scoped stages', () => {
+  assert.equal(isDocumentationPath('AGENTS.md'), true);
+  for (const eventName of ['pull_request', 'merge_group']) {
+    for (const files of [['AGENTS.md'], ['AGENTS.md', 'docs/guide.md']]) {
+      const scope = decision(files, { eventName });
+      assert.equal(scope.validation_stage, 'documentation');
+      assert.equal(scope.reason, 'documentation-only');
+      assert.equal(scope.docs_check, true);
+      assert.equal(scope.readme_check, false);
+      for (const key of ['native_check', 'format_check', 'network_check', 'applications_check', 'database_check']) {
+        assert.equal(scope[key], false, `${eventName}/${key}`);
+      }
+      validateGate(results(scope));
+      for (const outcome of ['skipped', 'failure', 'cancelled', undefined]) {
+        const invalid = results(scope);
+        invalid.validation.outputs.documentation_outcome = outcome;
+        assert.throws(() => validateGate(invalid), `${eventName}/${outcome}`);
+      }
+      for (const result of ['skipped', 'failure', 'cancelled', undefined]) {
+        const invalid = results(scope);
+        invalid.validation.result = result;
+        assert.throws(() => validateGate(invalid), `${eventName}/validation/${result}`);
+      }
+    }
+    assert.equal(decision(['AGENTS.md', 'README.md'], { eventName }).readme_check, true);
+  }
+});
+
+test('an exact root AGENTS.md Git change selects documentation through the real PR and merge-group classifier', t => {
+  const repo = repository(t);
+  const base = addSite(repo);
+  repo.write('AGENTS.md', '# Contributor and agent instructions\n');
+  const head = repo.commit();
+  assert.deepEqual(changedPaths({ root: repo.root, base, head }), ['AGENTS.md']);
+  for (const eventName of ['pull_request', 'merge_group']) {
+    const payload = eventName === 'pull_request' ? { pull_request: { base: { sha: base }, head: { sha: head } } } :
+      { merge_group: { base_sha: base, head_sha: head } };
+    const { plan: scope, output } = classifyEvent(repo, eventName, payload);
+    assert.equal(scope.validation_stage, 'documentation');
+    assert.equal(scope.docs_check, true);
+    assert.equal(scope.readme_check, false);
+    for (const key of ['native_check', 'format_check', 'network_check', 'applications_check', 'database_check']) {
+      assert.equal(scope[key], false, `${eventName}/${key}`);
+      assert.match(output, new RegExp(`^${key}=false$`, 'm'));
+    }
+    validateGate(results(scope));
+  }
+});
+
+test('AGENTS neighbors and nested unknown paths cannot inherit the root documentation exception', () => {
+  const paths = ['agents.md', 'AGENTS.MD', 'AGENTS_CN.md', 'AGENTS.md.bak', 'AGENTS.md.js',
+    'AGENTS.cpp', 'AGENTS.md.hpp', 'nested/AGENTS.md', 'src/AGENTS.md', 'tests/AGENTS.md',
+    'src/plugins/net/AGENTS.md', '.github/AGENTS.md', 'docs/AGENTS.cpp', './AGENTS.md',
+    'nested/../AGENTS.md', 'nested//AGENTS.md', 'nested\\AGENTS.md'];
+  for (const file of paths) {
+    assert.equal(isDocumentationPath(file), false, file);
+    for (const eventName of ['pull_request', 'merge_group']) {
+      const scope = decision(['AGENTS.md', file], { eventName });
+      assert.equal(scope.native_check, true, `${eventName}/${file}`);
+      assert.equal(scope.format_check, true);
+      assert.equal(scope.docs_check, true);
+      for (const job of ['network', 'applications', 'database']) assert.equal(scope[`${job}_check`], true);
+      validateGate(results(scope));
+    }
+  }
+});
+
+test('AGENTS mixed with code keeps source module selection and every merge-candidate native module', () => {
+  for (const eventName of ['pull_request', 'merge_group']) {
+    const scope = decision(['AGENTS.md', 'tests/core/containers.cpp'], { eventName });
+    assert.equal(scope.native_check, true);
+    assert.equal(scope.docs_check, true);
+    assert.equal(scope.format_check, true);
+    assert.equal(scope.validation_stage, eventName === 'pull_request' ? 'modules' : 'full');
+    for (const job of ['network', 'applications', 'database']) {
+      assert.equal(scope[`${job}_check`], eventName !== 'pull_request' || job === 'applications');
+    }
+    validateGate(results(scope));
+  }
+});
+
+test('AGENTS never exempts manual events, unavailable sites or uncertain changed paths from native checks', () => {
+  for (const extra of [{ eventName: 'workflow_dispatch' }, { enumerationFailed: true },
+    { site: { present: true, available: false } }, { site: { present: false, available: false } }]) {
+    const scope = decision(['AGENTS.md'], extra);
+    assert.equal(scope.native_check, true);
+    assert.equal(scope.validation_stage, 'full');
+    for (const job of ['network', 'applications', 'database']) assert.equal(scope[`${job}_check`], true);
+    if (extra.site?.present) assert.equal(scope.docs_check, true);
+    validateGate(results(scope));
+  }
+});
+
 test('only the two exact plugin indexes select documentation and keep root README checks separate', () => {
   const indexes = ['src/plugins/README.md', 'src/plugins/README_CN.md'];
   for (const eventName of ['pull_request', 'merge_group']) {