overleaf-mcp

An MCP server for Overleaf that lets AI assistants (Claude, Cursor, etc.) read, edit, and compile your LaTeX projects directly — no more copy-pasting between the editor and your terminal.

No paid plan required. Overleaf's official Git integration is locked behind a paid subscription. This project instead authenticates the same way your browser does — with a session cookie — and drives the same HTTP and realtime endpoints the Overleaf web app itself uses. It works on the free plan.

⚠️ Before you use this

• This talks to undocumented, unofficial endpoints, including Overleaf's legacy Socket.IO realtime channel (used to resolve folder ids for uploads/deletes). It can break without notice if Overleaf changes its backend.

• Your session cookie is as powerful as your password for the duration of the session. Treat it like a secret: it's read from an environment variable and never leaves your machine, but don't paste it anywhere else.

• This is not affiliated with or endorsed by Overleaf/Writefull. Use it at your own risk and in line with Overleaf's Terms of Service.

Install

git clone https://github.com/NiccoloSalvini/overleaf-mcp
cd overleaf-mcp
uv sync

Get your session cookie

1. Log into overleaf.com in your browser.

2. Open devtools → Application (Chrome) or Storage (Firefox) → Cookies → https://www.overleaf.com.

3. Copy the value of overleaf_session2 (and GCLB if present).

4. Build a Cookie: header string:

   overleaf_session2=<value>; GCLB=<value>

   Easiest way in Chrome: open the Network tab, reload the dashboard, click any request to overleaf.com, and copy the full Cookie request header from Headers → Request Headers.

The cookie expires (Overleaf sessions typically last a few weeks). When tools start failing with an authentication error, repeat these steps and update the environment variable.

Configure

Set the cookie as an environment variable:

export OVERLEAF_COOKIE="overleaf_session2=...; GCLB=..."

Claude Code

claude mcp add overleaf --env OVERLEAF_COOKIE="overleaf_session2=...; GCLB=..." -- uv --directory /path/to/overleaf-mcp run overleaf-mcp

Claude Desktop (claude_desktop_config.json)

{
  "mcpServers": {
    "overleaf": {
      "command": "uv",
      "args": ["--directory", "/path/to/overleaf-mcp", "run", "overleaf-mcp"],
      "env": {
        "OVERLEAF_COOKIE": "overleaf_session2=...; GCLB=..."
      }
    }
  }
}

Tools

Every tool that takes a project argument accepts either the 24-character project id or the exact project name.

All eight tools were live-tested 2026-07-19 against a real account, including create/upload/verify/delete round trips on disposable test projects. overleaf_list_projects/overleaf_pull needed a fix (Overleaf renamed a meta tag). overleaf_push_file needed a bigger one: black-box guessing at the upload request shape (field names, folder_id vs parent_folder_id, with/without qqtotalfilesize) consistently got 422 invalid_filename, even with a correct folder id read out of Overleaf's own React state. The actual cause, found by reading Overleaf's own source (services/web/app/src/Features/Uploads/ProjectUploadController.mjs in overleaf/overleaf, AGPL): the filename comes from a multipart form field name, not from a qqfilename query string param the way the legacy Fine Uploader-era endpoint mapping (and every third-party client that copied it, including the original version of this one) assumed. folder_id and _csrf genuinely are query params — only the filename field was wrong. Fixed in client.py.

overleaf_push_file, overleaf_push_dir, and overleaf_delete_file first join Overleaf's realtime channel to resolve folder ids (the only way to get them without the paid Git API) — expect these to take a few seconds longer, and to be the first thing that breaks if Overleaf changes its backend.

How it works

• List / pull: the Overleaf dashboard (GET /project) embeds the project list as JSON in a <meta name="ol-prefetchedProjectsBlob"> tag, and a CSRF token in <meta name="ol-csrfToken">. Projects download as a zip from GET /project/{id}/download/zip. Both are plain HTTP + HTML parsing.

• Push / delete: uploading or deleting a file requires the internal folder id, which Overleaf only exposes over its realtime channel (a joinProject Socket.IO event, using Overleaf's legacy pre-1.0 Socket.IO protocol). This project joins that channel, reads the returned folder tree, and then calls the same REST upload/delete endpoints the editor uses.

• Compile: POST /project/{id}/compile with a CSRF token, same as the in-browser editor's build button.

Endpoint mapping originally traced from moritzgloeckl/overleaf-sync (MIT licensed), reimplemented here with httpx and typed models.

Development

uv sync --group dev
uv run pytest
uv run ruff check .

License

MIT — see LICENSE.