diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 11da75d..3f8e5f7 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -32,6 +32,10 @@ jobs:
         run: git diff --check "$(git hash-object -t tree /dev/null)" HEAD
       - name: Validate provider catalogs
         run: node scripts/validate-provider-catalogs.mjs
+      - name: Verify generated agent skill against its canonical source
+        run: |
+          node --test scripts/sync-agent-skill.test.mjs
+          npm run skills:check
       - name: Install JSON Schema validation dependencies
         run: npm ci --ignore-scripts --no-audit
       - name: Validate machine-readable output schema
diff --git a/AGENTS.md b/AGENTS.md
index f810f27..f9283e4 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -21,5 +21,7 @@ Write repository content, code comments, commit messages, issues, and pull reque
 
 ## Delivery
 
+- Agent guidance is generated from the pinned `stack-sh/docs` source. Edit shared instructions there, then update `skills/docs-source.json` and run `npm run skills:sync`. Never hand-edit the generated skill; verify with `npm run skills:check` and the CLI integration tests.
+
 - Use a topic branch and pull request; squash merge after approval.
 - Work in small increments and add repository-specific formatting, linting, tests, and release checks with the code that needs them.
diff --git a/README.md b/README.md
index 180d594..2a98359 100644
--- a/README.md
+++ b/README.md
@@ -107,8 +107,13 @@ for usage and the [skill source](./skills/stack-diagrams/SKILL.md) for review.
 To pin reviewed instructions, check out a specific commit of this repository and
 run `npx skills add /absolute/path/to/cli --skill stack-diagrams`.
 
-The CLI repository owns these instructions; the website owns the usage guides.
-Process-level tests execute the skill's command examples against the built CLI.
+The shared instruction source lives in [stack-sh/docs](https://github.com/stack-sh/docs).
+This repository distributes its generated skill; do not edit `SKILL.md` directly.
+`skills/docs-source.json` pins the reviewed Docs commit and manifest SHA-256.
+After merging a Docs change, update that lock and run `npm run skills:sync`.
+`npm run skills:check` verifies the manifest, artifact hash, and exact local bytes;
+CI rejects drift. Process-level tests also execute the generated commands against
+the built CLI. Updating the skill does not require a new CLI binary release.
 
 ## Development
 
diff --git a/package.json b/package.json
index 7861baa..e5009e2 100644
--- a/package.json
+++ b/package.json
@@ -3,6 +3,8 @@
   "private": true,
   "type": "module",
   "scripts": {
+    "skills:check": "node scripts/sync-agent-skill.mjs --check",
+    "skills:sync": "node scripts/sync-agent-skill.mjs --sync",
     "test:cli-output-schema": "node scripts/validate-cli-output-schema.mjs && node --test scripts/cli-output-schema.test.mjs",
     "test:consumer-prototype": "node examples/consume-cli-json.mjs check tests/fixtures/render.stack"
   },
diff --git a/scripts/sync-agent-skill.mjs b/scripts/sync-agent-skill.mjs
new file mode 100644
index 0000000..696262b
--- /dev/null
+++ b/scripts/sync-agent-skill.mjs
@@ -0,0 +1,48 @@
+import assert from 'node:assert/strict';
+import { createHash } from 'node:crypto';
+import { readFile, writeFile } from 'node:fs/promises';
+import path from 'node:path';
+import { fileURLToPath } from 'node:url';
+
+const root = fileURLToPath(new URL('../', import.meta.url));
+const skillPath = 'skills/stack-diagrams/SKILL.md';
+const digest = bytes => createHash('sha256').update(bytes).digest('hex');
+
+export async function fetchSkill(lock, fetchResource = fetch) {
+  assert.equal(lock.repository, 'stack-sh/docs');
+  assert.match(lock.revision, /^[a-f0-9]{40}$/);
+  assert.match(lock.manifestSha256, /^[a-f0-9]{64}$/);
+  const base = `https://raw.githubusercontent.com/${lock.repository}/${lock.revision}/generated/`;
+  const get = async file => {
+    const response = await fetchResource(base + file, { signal: AbortSignal.timeout(15_000) });
+    assert.ok(response.ok, `Docs resource unavailable: ${file} (HTTP ${response.status})`);
+    const bytes = Buffer.from(await response.arrayBuffer());
+    assert.ok(bytes.length <= 1_048_576, 'Docs resource exceeds size limit');
+    return bytes;
+  };
+  const manifestBytes = await get('manifest.json');
+  assert.equal(digest(manifestBytes), lock.manifestSha256, 'Docs manifest integrity mismatch');
+  const manifest = JSON.parse(manifestBytes.toString('utf8'));
+  assert.equal(manifest.schemaVersion, '1.0', 'Unsupported Docs manifest version');
+  assert.ok(Array.isArray(manifest.files));
+  const entries = manifest.files.filter(entry => entry.path === skillPath);
+  assert.equal(entries.length, 1, 'Expected exactly one skill artifact');
+  assert.match(entries[0].sha256, /^[a-f0-9]{64}$/);
+  const bytes = await get(skillPath);
+  assert.equal(digest(bytes), entries[0].sha256, 'Docs skill integrity mismatch');
+  return bytes;
+}
+
+export async function syncSkill(directory = root, write = false, fetchResource = fetch) {
+  const lock = JSON.parse(await readFile(path.join(directory, 'skills/docs-source.json'), 'utf8'));
+  const bytes = await fetchSkill(lock, fetchResource);
+  const target = path.join(directory, skillPath);
+  if (write) await writeFile(target, bytes);
+  else assert.deepEqual(await readFile(target), bytes, 'Generated skill drift: update Docs source, then run npm run skills:sync');
+}
+
+if (process.argv[1] && path.resolve(process.argv[1]) === fileURLToPath(import.meta.url)) {
+  assert.ok(process.argv.slice(2).every(arg => ['--check', '--sync'].includes(arg)));
+  assert.ok(!(process.argv.includes('--check') && process.argv.includes('--sync')));
+  await syncSkill(root, process.argv.includes('--sync'));
+}
diff --git a/scripts/sync-agent-skill.test.mjs b/scripts/sync-agent-skill.test.mjs
new file mode 100644
index 0000000..16ce286
--- /dev/null
+++ b/scripts/sync-agent-skill.test.mjs
@@ -0,0 +1,49 @@
+import assert from 'node:assert/strict';
+import { createHash } from 'node:crypto';
+import { mkdir, mkdtemp, readFile, rm, writeFile } from 'node:fs/promises';
+import os from 'node:os';
+import path from 'node:path';
+import test from 'node:test';
+import { fetchSkill, syncSkill } from './sync-agent-skill.mjs';
+
+const digest = text => createHash('sha256').update(text).digest('hex');
+const content = 'canonical skill\n';
+function fixture(schemaVersion = '1.0') {
+  const manifest = JSON.stringify({ schemaVersion, files: [{ path: 'skills/stack-diagrams/SKILL.md', sha256: digest(content) }] });
+  const lock = { repository: 'stack-sh/docs', revision: 'a'.repeat(40), manifestSha256: digest(manifest) };
+  const fetchResource = async url => {
+    assert.ok(url.startsWith(`https://raw.githubusercontent.com/stack-sh/docs/${lock.revision}/generated/`));
+    return new Response(url.endsWith('manifest.json') ? manifest : content);
+  };
+  return { lock, manifest, fetchResource };
+}
+
+test('fetches only immutable provider artifacts with verified hashes', async () => {
+  const { lock, fetchResource } = fixture();
+  assert.equal((await fetchSkill(lock, fetchResource)).toString(), content);
+});
+
+test('rejects mutable refs, unsupported schemas, missing resources, and tampering', async () => {
+  const { lock, manifest, fetchResource } = fixture();
+  await assert.rejects(fetchSkill({ ...lock, revision: 'main' }, fetchResource));
+  await assert.rejects(fetchSkill(lock, async () => new Response('', { status: 404 })), /HTTP 404/);
+  await assert.rejects(fetchSkill(lock, async () => new Response('altered')), /manifest integrity/);
+  await assert.rejects(fetchSkill(lock, async url => new Response(url.endsWith('manifest.json') ? manifest : 'altered')), /skill integrity/);
+  const newer = fixture('2.0');
+  await assert.rejects(fetchSkill(newer.lock, newer.fetchResource), /Unsupported Docs manifest/);
+});
+
+test('check is read-only, rejects drift, and explicit sync restores canonical bytes', async t => {
+  const directory = await mkdtemp(path.join(os.tmpdir(), 'stack-cli-docs-source-'));
+  t.after(() => rm(directory, { recursive: true, force: true }));
+  const { lock, fetchResource } = fixture();
+  await mkdir(path.join(directory, 'skills/stack-diagrams'), { recursive: true });
+  await writeFile(path.join(directory, 'skills/docs-source.json'), JSON.stringify(lock));
+  const target = path.join(directory, 'skills/stack-diagrams/SKILL.md');
+  await writeFile(target, 'manual change');
+  await assert.rejects(syncSkill(directory, false, fetchResource), /Generated skill drift/);
+  assert.equal(await readFile(target, 'utf8'), 'manual change');
+  await syncSkill(directory, true, fetchResource);
+  await syncSkill(directory, false, fetchResource);
+  assert.equal(await readFile(target, 'utf8'), content);
+});
diff --git a/skills/docs-source.json b/skills/docs-source.json
new file mode 100644
index 0000000..905d2b9
--- /dev/null
+++ b/skills/docs-source.json
@@ -0,0 +1,5 @@
+{
+  "repository": "stack-sh/docs",
+  "revision": "69e4615c5356b44517fa557bea248ea2fe008631",
+  "manifestSha256": "3f84b30a4fb6216c96b13b53035bf62003504eee686fd7e44867c711da0fcfea"
+}
diff --git a/skills/stack-diagrams/SKILL.md b/skills/stack-diagrams/SKILL.md
index 5727171..e48f3ed 100644
--- a/skills/stack-diagrams/SKILL.md
+++ b/skills/stack-diagrams/SKILL.md
@@ -1,9 +1,11 @@
 ---
-name: stack-diagrams
-description: Create or edit Stack (.stack) software architecture diagrams, validate them with the Stack CLI, and render SVG. Use for Stack diagrams or when a user chooses Stack for architecture documentation; not for infrastructure provisioning or unrelated programming stacks.
-license: Apache-2.0
+name: "stack-diagrams"
+description: "Create or edit Stack (.stack) software architecture diagrams, validate them with the Stack CLI, and render SVG. Use for Stack diagrams or when a user chooses Stack for architecture documentation; not for infrastructure provisioning or unrelated programming stacks."
+license: "Apache-2.0"
 ---
 
+<!-- Generated from stack-sh/docs/content/agent-workflow.md. Do not edit. -->
+
 # Stack diagrams
 
 Deliver editable `.stack` source and, when rendering is available, an SVG. Preserve the requested architecture and existing unrelated content. Stack describes architecture; it does not provision resources or execute application code.