diff --git a/src/routes/source.js b/src/routes/source.js
index 63d6cdd3..a1d508f1 100644
--- a/src/routes/source.js
+++ b/src/routes/source.js
@@ -26,11 +26,18 @@ export async function deleteSource({ req, env, daCtx }) {
 
 export async function postSource({ req, env, daCtx }) {
   if (!hasPermission(daCtx, daCtx.key, 'write')) return { status: 403 };
+
+  // Flag MCP-initiated writes so the version author is tagged as an agent.
+  // Done after the permission check, which also reads daCtx.users[].email.
+  const initiator = req.headers.get('x-da-initiator');
+  if (initiator === 'mcp' && Array.isArray(daCtx.users)) {
+    daCtx.users = daCtx.users.map((user) => ({ ...user, isAgentic: true }));
+  }
+
   const obj = await putHelper(req, env, daCtx);
   const resp = await putObject(env, daCtx, obj);
 
   if (resp.status === 201 || resp.status === 200) {
-    const initiator = req.headers.get('x-da-initiator');
     if (initiator !== 'collab') {
       await notifyCollab('syncadmin', req.url, env);
     }
diff --git a/src/storage/utils/version.js b/src/storage/utils/version.js
index 88159966..0a4258d9 100644
--- a/src/storage/utils/version.js
+++ b/src/storage/utils/version.js
@@ -52,5 +52,8 @@ export function getUsersForMetadata(users) {
     return undefined;
   }
 
-  return users.map((user) => ({ email: user.email }));
+  return users.map((user) => ({
+    email: user.email,
+    ...(user.isAgentic && { isAgentic: true }),
+  }));
 }
diff --git a/test/routes/source.test.js b/test/routes/source.test.js
index 27837947..89aef176 100644
--- a/test/routes/source.test.js
+++ b/test/routes/source.test.js
@@ -55,6 +55,53 @@ describe('Source Route', () => {
     assert.deepStrictEqual(['https://localhost/api/v1/syncadmin?doc=http://localhost:9876/source/somedoc.html'], sb_callbacks);
   });
 
+  it('Test postSource from mcp flags users as agent and still notifies collab', async () => {
+    const putCalled = [];
+    const putCall = (e, c, o) => {
+      putCalled.push({ e, c, o });
+      return { status: 200 };
+    };
+
+    const { postSource } = await esmock('../../src/routes/source.js', {
+      '../../src/storage/object/put.js': {
+        default: putCall,
+      },
+      '../../src/utils/auth.js': {
+        hasPermission: () => true,
+      },
+    });
+
+    const callbacks = [];
+    const env = {
+      dacollab: {
+        fetch: async (url) => {
+          callbacks.push(url);
+          return { body: { cancel: () => {} } };
+        },
+      },
+      DA_COLLAB: 'http://localhost:1234',
+    };
+
+    const headers = new Map();
+    headers.set('x-da-initiator', 'mcp');
+
+    const req = { headers, url: 'http://localhost:8787/source/a/b/mydoc.html' };
+    const daCtx = {
+      key: '/a/b/mydoc.html',
+      aclCtx: { pathLookup: new Map() },
+      users: [{ email: 'jane@example.com', ident: '123' }],
+    };
+
+    const resp = await postSource({ req, env, daCtx });
+    assert.equal(200, resp.status);
+    // users passed to putObject are flagged so the version author is an agent
+    assert.deepStrictEqual(
+      putCalled[0].c.users,
+      [{ email: 'jane@example.com', ident: '123', isAgentic: true }],
+    );
+    assert.equal(1, callbacks.length);
+  });
+
   it('Test postSource from collab does not trigger invalidate callback', async () => {
     const { postSource } = await esmock('../../src/routes/source.js', {
       '../../src/storage/object/put.js': {
diff --git a/test/storage/utils/version.test.js b/test/storage/utils/version.test.js
new file mode 100644
index 00000000..cd3a6921
--- /dev/null
+++ b/test/storage/utils/version.test.js
@@ -0,0 +1,44 @@
+/*
+ * Copyright 2025 Adobe. All rights reserved.
+ * This file is licensed to you under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License. You may obtain a copy
+ * of the License at http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under
+ * the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR REPRESENTATIONS
+ * OF ANY KIND, either express or implied. See the License for the specific language
+ * governing permissions and limitations under the License.
+ */
+import assert from 'node:assert';
+
+import { getUsersForMetadata } from '../../../src/storage/utils/version.js';
+
+describe('getUsersForMetadata', () => {
+  it('returns undefined when users is missing', () => {
+    assert.equal(getUsersForMetadata(undefined), undefined);
+  });
+
+  it('projects to email only, dropping ident/orgs', () => {
+    const users = [{ email: 'jane@example.com', ident: '123', orgs: [{}] }];
+    assert.deepStrictEqual(getUsersForMetadata(users), [{ email: 'jane@example.com' }]);
+  });
+
+  it('keeps the email clean and adds isAgentic when the user is an agent', () => {
+    const users = [{ email: 'jane@example.com', ident: '123', isAgentic: true }];
+    assert.deepStrictEqual(
+      getUsersForMetadata(users),
+      [{ email: 'jane@example.com', isAgentic: true }],
+    );
+  });
+
+  it('flags only the agent users in a mixed list', () => {
+    const users = [
+      { email: 'jane@example.com', isAgentic: true },
+      { email: 'bob@example.com' },
+    ];
+    assert.deepStrictEqual(getUsersForMetadata(users), [
+      { email: 'jane@example.com', isAgentic: true },
+      { email: 'bob@example.com' },
+    ]);
+  });
+});