diff --git a/.changeset/pin-reference-snapshot.md b/.changeset/pin-reference-snapshot.md
new file mode 100644
index 0000000..89f670b
--- /dev/null
+++ b/.changeset/pin-reference-snapshot.md
@@ -0,0 +1,5 @@
+---
+'datocms': patch
+---
+
+Pin reference downloads to an immutable revision so documentation remains available when upstream files move.
diff --git a/packages/cli/src/commands/agents/reference.ts b/packages/cli/src/commands/agents/reference.ts
index 00235af..12c36fe 100644
--- a/packages/cli/src/commands/agents/reference.ts
+++ b/packages/cli/src/commands/agents/reference.ts
@@ -2,7 +2,7 @@ import { BaseCommand, oclif } from '@datocms/cli-utils';
 
 const NAME_PATTERN = /^[a-z0-9-]+$/;
 const SKILLS_BASE_URL =
-  'https://raw.githubusercontent.com/datocms/agent-skills/refs/heads/master/skills/';
+  'https://raw.githubusercontent.com/datocms/agent-skills/86c533b74c2913e590797eb0b2622d2cdfe5cf68/skills/';
 
 export default class Command extends BaseCommand {
   static hidden = true;
diff --git a/packages/cli/test/commands/agents-reference.test.ts b/packages/cli/test/commands/agents-reference.test.ts
new file mode 100644
index 0000000..758861b
--- /dev/null
+++ b/packages/cli/test/commands/agents-reference.test.ts
@@ -0,0 +1,84 @@
+import { runCommand } from '@oclif/test';
+import { expect } from 'chai';
+
+const REFERENCE_URL =
+  'https://raw.githubusercontent.com/datocms/agent-skills/86c533b74c2913e590797eb0b2622d2cdfe5cf68/skills/datocms-cma/references/editing-records.md';
+
+describe('agents:reference', () => {
+  const originalFetch = globalThis.fetch;
+  let requestedUrls: string[];
+  let respond: () => Promise<Response>;
+
+  beforeEach(() => {
+    requestedUrls = [];
+    respond = async () => new Response('# Editing records');
+    globalThis.fetch = async (input) => {
+      requestedUrls.push(String(input));
+      return respond();
+    };
+  });
+
+  afterEach(() => {
+    globalThis.fetch = originalFetch;
+  });
+
+  const run = () =>
+    runCommand(['agents:reference', 'datocms-cma', 'editing-records'], {
+      root: process.cwd(),
+    });
+
+  it('fetches the pinned document and adds a missing trailing newline', async () => {
+    const { stdout, error } = await run();
+    expect(error).to.equal(undefined);
+    expect(requestedUrls).to.deep.equal([REFERENCE_URL]);
+    expect(stdout).to.equal('# Editing records\n');
+  });
+
+  it('preserves a document that already ends in a newline', async () => {
+    respond = async () => new Response('# Editing records\n');
+    const { stdout, error } = await run();
+    expect(error).to.equal(undefined);
+    expect(stdout).to.equal('# Editing records\n');
+  });
+
+  it('rejects path traversal before fetching', async () => {
+    for (const args of [
+      ['../datocms-cma', 'editing-records'],
+      ['datocms-cma', '../editing-records'],
+    ]) {
+      const { error } = await runCommand(['agents:reference', ...args], {
+        root: process.cwd(),
+      });
+      expect(error?.message).to.match(/Invalid (skill|reference) name/);
+    }
+    expect(requestedUrls).to.deep.equal([]);
+  });
+
+  it('reports a missing reference with its pinned URL', async () => {
+    respond = async () => new Response('', { status: 404 });
+    const { stdout, error } = await run();
+    expect(stdout).to.equal('');
+    expect(error?.message).to.equal(
+      `Reference "editing-records" not found at ${REFERENCE_URL}`,
+    );
+  });
+
+  it('preserves HTTP error details', async () => {
+    respond = async () =>
+      new Response('', { status: 503, statusText: 'Service Unavailable' });
+    const { error } = await run();
+    expect(error?.message).to.equal(
+      'Failed to fetch reference "editing-records": HTTP 503 Service Unavailable',
+    );
+  });
+
+  it('preserves network error details', async () => {
+    respond = async () => {
+      throw new Error('Connection failed');
+    };
+    const { error } = await run();
+    expect(error?.message).to.equal(
+      'Failed to fetch reference "editing-records": Connection failed',
+    );
+  });
+});
diff --git a/packages/cli/test/commands/help.test.ts b/packages/cli/test/commands/help.test.ts
index bbb9a56..68bf9cb 100644
--- a/packages/cli/test/commands/help.test.ts
+++ b/packages/cli/test/commands/help.test.ts
@@ -1,7 +1,12 @@
 import { runCommand } from '@oclif/test';
 import { expect } from 'chai';
 
-describe('datocms', async () => {
-  const { stdout } = await runCommand('help');
-  expect(stdout).to.contain('plugins');
+describe('datocms', () => {
+  it('shows the available commands', async () => {
+    const { stdout, error } = await runCommand('help', {
+      root: process.cwd(),
+    });
+    expect(error).to.equal(undefined);
+    expect(stdout).to.contain('plugins');
+  });
 });