Coauthor (CKEditor MCP)

Coauthor is the backend part of the Editing Toolkit. It lets AI agents read and edit CKEditor 5 documents on the server through the Model Context Protocol (MCP), without anyone having the document open in a browser. Your agents connect to its MCP server to apply direct edits or Track Changes suggestions. Backend code can also call the same tools over REST without using an AI model. With real-time collaboration, people can keep editing the same document while agents work.

A backend agent drafts a report from your application’s data. A second agent reads it and leaves comments on the sections a person should check. The reviewer opens the document in CKEditor 5 and starts from those comments.

Coauthor lets both agents work on the same document in a server-side CKEditor 5 instance, without anyone having it open in a browser. Agents can check their output against the editor’s features and configuration and use the feedback to revise it before applying it. An editor retains only the HTML its features support, so unsupported markup can be lost during import.

The server-side editor runs the same editor bundle that you upload to Cloud Services, so it has the same features, plugins, and configuration as the editor your users see.

Coauthor exposes three things to an agent:

• Skills available through MCP tools describe how the editor works and which features the document supports. They help agents produce HTML the editor accepts.
• Tools available through MCP and REST let agents and backend code read, edit, and verify document content and add comments.
• A server-side CKEditor 5 instance uses Compare to apply direct edits or Track Changes suggestions. These changes work with real-time collaboration, comments, and revision history.

• Run agents that draft, review, and edit documents without an open browser editor. For example, one agent writes a first draft and a second one checks it. See the backend agent workflows guide.
• Let users start document editing tasks in an app such as Claude or ChatGPT and review the results in CKEditor 5. See the agent apps guide.
• Build your own AI features. Coauthor helps your agent produce content the editor accepts, and Compare presents the result for review in the browser. See the custom chat implementation guide.

Coauthor works with and without real-time collaboration. With real-time collaboration, document storage follows your collaboration setup. Otherwise, your integration determines how Coauthor loads and saves documents.

Contact us for setup guidance during early access. Server-side setup needs to cover the MCP endpoint, authentication, and the editor bundle used by the server-side editor.

Coauthor is part of the Editing Toolkit and is in early access. It is not enabled in the free trial by default. Contact us to join the early access program and enable Coauthor in your trial or existing environment. General availability is planned for the first quarter of 2027.