GitLab MCP Server (OAuth)

A production-ready MCP (Model Context Protocol) server that lets AI agents interact with GitLab through a curated set of 20 tools. Every user authenticates with their own GitLab account via OAuth 2.0 — no Personal Access Tokens. The server calls the GitLab REST API directly (no glab CLI).

User → GitLab OAuth Login → MCP Server → GitLab REST API

Features

• Per-user OAuth 2.0 login (PKCE + state), token auto-refresh, logout.

• MCP-client OAuth (zero token paste) — the server is its own OAuth 2.0 Authorization Server: Dynamic Client Registration + authorization-code/PKCE, with opaque, rotating refresh tokens (reuse detection revokes the whole rotation family). GitLab is the upstream identity provider. Manual bearer-token paste remains as a fallback.

• Server-issued bearer tokens — the client sends one bearer token; the server maps it to that user's GitLab session.

• Secure token storage — GitLab tokens encrypted at rest (AES-256-GCM); session tokens stored only as sha-256 hashes.

• Strict tool allowlist — only the 20 tools below; no raw API proxy, no admin/destructive operations.

• Real GitLab authorization — every action runs as the authenticated user with their own token; project access is checked before each call.

• Audit logging — every tool call recorded in PostgreSQL (secrets stripped).

• Streamable HTTP MCP transport, PostgreSQL + Prisma.

• Docker Compose one-command deploy. Vitest unit + integration tests.

Related MCP server: GitLab MR MCP

The 20 tools

Merge requests: create_merge_request, update_merge_request, get_merge_request, list_merge_requests, get_merge_request_diff, get_merge_request_versions.

Comments & discussions: add_comment, list_merge_request_discussions, reply_to_discussion.

Review actions: assign_reviewer, set_labels, approve_merge_request, unapprove_merge_request.

Pipelines & jobs: get_pipeline_status, list_pipelines, get_pipeline_jobs, get_job_log.

Repository: get_file_content (read a file at a given ref; read-only).

User lookup: get_current_user, find_user.

Quick start (Docker)

1. Create a GitLab OAuth application (User Settings → Applications, or an instance/group app). See docs/oauth.md for details.

   • Scopes: read_user, api

   • Redirect URI: http://localhost:3000/auth/callback

   • Copy the Application ID and Secret.

2. Configure environment:

   cp .env.example .env
   # edit .env: set GITLAB_CLIENT_ID, GITLAB_CLIENT_SECRET, GITLAB_REDIRECT_URI
   # and generate an encryption key:
   openssl rand -hex 32          # paste into ENCRYPTION_KEY

   For self-hosted GitLab, also set GITLAB_BASE_URL.

3. Run the stack (Postgres + app, migrations run automatically):

   docker compose up --build

4. Log in & get your token: open http://localhost:3000/auth/login in a browser, authorize with GitLab, and copy the bearer token shown.

5. Configure your MCP client to use the Streamable HTTP endpoint:

   • URL: http://localhost:3000/mcp

   • Header: Authorization: Bearer <your-token>

   Example (clients supporting remote HTTP MCP servers with headers):

   {
     "mcpServers": {
       "gitlab": {
         "type": "http",
         "url": "http://localhost:3000/mcp",
         "headers": { "Authorization": "Bearer <your-token>" }
       }
     }
   }

To disconnect: curl -X POST http://localhost:3000/auth/logout -H "Authorization: Bearer <token>".

Local development (without Docker for the app)

# Start datastores only:
docker compose up -d postgres

cp .env.example .env          # set GitLab creds + ENCRYPTION_KEY
# point DATABASE_URL at localhost (the defaults already do)

npm install
npm run db:generate
npm run db:migrate            # creates/apply migrations locally
npm run dev                   # http://localhost:3000

Tests

npm test

GitLab is always mocked — no live calls and no credentials required.

Documentation

• Setup guide

• OAuth configuration guide

• Deployment guide

• Security review

• Architecture

• CLAUDE.md — repo conventions / hard rules for contributors.

License

MIT