cerngitlab-mcp 0.1.2

MCP server for CERN GitLab - code discovery, documentation access, and usage examples for HEP projects

CERN GitLab MCP Server

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

Features

• 13 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, issue search
• Robust — rate limiting, retries with exponential backoff, graceful error handling

Installation

Requires Python 3.10+.

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:

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

Note: The code search (search_code), issue search (search_issues), 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

Project-specific (default) — installs in the current directory's configuration:

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

Global — installs for your user account (works in all projects):

claude mcp add --scope user cerngitlab-mcp -- uvx cerngitlab-mcp

To include authentication, add -e CERNGITLAB_TOKEN=glpat-xxxxxxxxxxxx before the --:

# Example: Global installation with token
claude mcp add --scope user -e CERNGITLAB_TOKEN=glpat-xxxxxxxxxxxx cerngitlab-mcp -- uvx cerngitlab-mcp

Manual Configuration — you can also manually edit your global config at ~/.claude.json (on Linux/macOS) or %APPDATA%\Claude\claude.json (on Windows):

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

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*
search_issues	Search for issues and discussions	Yes
get_wiki_pages	Access repository wiki pages	Yes
inspect_project	Analyze project structure, build system, dependencies, and CI	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 docs/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"

Analyze a project structure

"Inspect the lhcb/allen project to understand its build system, dependencies, and CI pipeline configuration"

Find usage context

"Search for issues related to 'segmentation fault' in the atlas/athena project to see if others have encountered this"

Track releases

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

Find framework configurations

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

Development

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

License

AGPL-3.0