CERN GitLab MCP Server

An MCP server that connects LLMs to CERN GitLab for discovering HEP code, documentation, and analysis examples.

Features

14 MCP tools for searching, browsing, and analyzing CERN GitLab repositories
Public access — works without authentication for public repositories
HEP-focused — dependency parsing for Python and C++ ecosystems, binary detection for .root files
Robust — rate limiting, retries with exponential backoff, graceful error handling

Installation

Requires Python 3.14+.

Quickstart (recommended)

No installation needed — just use uvx to run directly:

uvx cerngitlab-mcp

From PyPI

pip install cerngitlab-mcp

From source

git clone https://github.com/MohamedElashri/cerngitlab-mcp
cd cerngitlab-mcp
uv sync

Configuration

All settings are configured via environment variables prefixed with CERNGITLAB_:

Variable	Default	Description
`CERNGITLAB_GITLAB_URL`	`https://gitlab.cern.ch`	GitLab instance URL
`CERNGITLAB_TOKEN`	(empty)	Personal access token (optional)
`CERNGITLAB_TIMEOUT`	`30`	HTTP timeout in seconds
`CERNGITLAB_MAX_RETRIES`	`3`	Max retries for failed requests
`CERNGITLAB_RATE_LIMIT_PER_MINUTE`	`300`	API rate limit
`CERNGITLAB_LOG_LEVEL`	`INFO`	Logging level

Authentication

The server works in two modes:

Without token — Access to all public repositories. Sufficient for most HEP code discovery.
With token — Additional access to internal/private projects, code search, and wiki pages.

To create a token:

Go to https://gitlab.cern.ch/-/user_settings/personal_access_tokens
Create a token with read_api scope
Set CERNGITLAB_TOKEN=glpat-xxxxxxxxxxxx

Note: The code search (search_code) and wiki (get_wiki_pages) tools require authentication on CERN GitLab.

Usage

Claude Desktop

Add to your claude_desktop_config.json:

{
  "mcpServers": {
    "cerngitlab": {
      "command": "uvx",
      "args": ["cerngitlab-mcp"],
      "env": {
        "CERNGITLAB_TOKEN": "glpat-xxxxxxxxxxxx"
      }
    }
  }
}

Claude Code

claude mcp add cerngitlab-mcp -- uvx cerngitlab-mcp

To include authentication:

claude mcp add cerngitlab-mcp -e CERNGITLAB_TOKEN=glpat-xxxxxxxxxxxx -- uvx cerngitlab-mcp

GitHub Copilot

Add to your VS Code settings.json:

{
  "mcp": {
    "servers": {
      "cerngitlab": {
        "command": "uvx",
        "args": ["cerngitlab-mcp"],
        "env": {
          "CERNGITLAB_TOKEN": "glpat-xxxxxxxxxxxx"
        }
      }
    }
  }
}

Or add a .vscode/mcp.json to your project:

{
  "servers": {
    "cerngitlab": {
      "command": "uvx",
      "args": ["cerngitlab-mcp"],
      "env": {
        "CERNGITLAB_TOKEN": "glpat-xxxxxxxxxxxx"
      }
    }
  }
}

Gemini CLI

Add to your ~/.gemini/settings.json:

{
  "mcpServers": {
    "cerngitlab": {
      "command": "uvx",
      "args": ["cerngitlab-mcp"],
      "env": {
        "CERNGITLAB_TOKEN": "glpat-xxxxxxxxxxxx"
      }
    }
  }
}

Direct usage

# Run with uvx (no install needed)
uvx cerngitlab-mcp

# Or if installed from PyPI
cerngitlab-mcp

# Or from source
uv run cerngitlab-mcp

# With authentication
CERNGITLAB_TOKEN=glpat-xxx uvx cerngitlab-mcp

Tools

Tool	Description	Auth required
`search_repositories`	Search public repositories by keywords, topics, or language	No
`get_repository_info`	Get repository details (languages, stats, license)	No
`list_repository_files`	Browse the file tree of a repository	No
`get_file_content`	Retrieve file content with binary detection	No
`get_repository_readme`	Get the README file (tries common filenames)	No
`search_code`	Search for code across repositories	Yes*
`get_wiki_pages`	Access repository wiki pages	Yes
`analyze_dependencies`	Parse dependency files (Python, C++, Fortran)	No
`get_ci_config`	Retrieve and analyze `.gitlab-ci.yml`	No
`get_build_config`	Find build config files (CMake, Make, setuptools, etc.)	No
`list_releases`	List releases from a repository	No
`get_release`	Get details of a specific release	No
`list_tags`	List repository tags with optional filtering	No
`test_connectivity`	Test connection to the GitLab instance	No

* search_code works without auth for project-scoped search (uses fallback grep). Global search requires authentication.

For detailed parameter documentation, see dev.md.

Example Prompts

Search for repositories

"Search CERN GitLab for Python repositories related to ROOT analysis and show me the most starred ones"

Understand a project

"Get the README and file structure of the lhcb/DaVinci project on CERN GitLab"

Find fitting examples

"Search for repositories on CERN GitLab that use RooFit and show me example fitting code"

Check dependencies

"What are the dependencies of the lhcb/allen project? Show me the CMakeLists.txt and any Python requirements"

Track releases

"List the recent releases of lhcb/DaVinci and show me the release notes for the latest version"

Explore CI/CD

"Get the CI/CD configuration of the lhcb/allen project and explain the pipeline stages"

Find framework configurations

"Search for Gaudi framework configuration files on CERN GitLab and show me examples"

Development

See dev.md for development setup, project structure, testing, and release instructions.

License

AGPL-3.0

CERN GitLab MCP Server