Atlasopenmagic

MCP Server for ATLAS Open Data metadata and file retrieval.

This server wraps the atlasopenmagic Python library as an MCP (Model Context Protocol) server, allowing LLMs to discover, query, and retrieve ATLAS Open Data datasets.

Architecture

LLM <--MCP/stdio--> atlasopenmagic-mcp serve <--HTTPS--> ATLAS Open Data API
                                                          (atlasopenmagic-api.app.cern.ch)

No authentication is required — all ATLAS Open Data is publicly accessible.

Installation

pip install atlasopenmagic-mcp

Or with pixi:

pixi install

Usage

As an MCP server

atlasopenmagic-mcp serve

Claude Desktop configuration

Add to your claude_desktop_config.json:

{
  "mcpServers": {
    "atlas-open-data": {
      "command": "atlasopenmagic-mcp",
      "args": ["serve"]
    }
  }
}

Available Tools

Tool	Description
atlas_available_releases	List all available data releases
atlas_set_release	Set the active release for subsequent queries
atlas_get_current_release	Get the currently active release
atlas_available_datasets	List dataset numbers (DSIDs) in the current release
atlas_available_skims	List available event skims
atlas_available_keywords	List physics keywords used in the release
atlas_get_metadata_fields	List available metadata fields
atlas_get_metadata	Get metadata for a dataset (no file lists)
atlas_get_all_info	Get complete dataset info including file URLs
atlas_match_metadata	Search datasets by metadata field values
atlas_get_urls	Get file URLs with skim and protocol options
atlas_get_weights	Get MC weight metadata for a dataset
atlas_get_all_weights_for_release	Get weights for all datasets in a release

Available Resources

URI	Description
atlas-open-data://guide	Quick reference for ATLAS Open Data concepts
atlas-open-data://metadata-fields	Complete metadata fields reference

Development

# Run tests
pixi run test

# Run linting
pixi run lint

# Run all checks
pixi run check-all

Keeping in sync with atlasopenmagic

This server depends on atlasopenmagic as a pip dependency. When the upstream library is updated:

1. Non-breaking changes (new fields, new releases): work automatically — the MCP tools call through to atlasopenmagic functions, so new data surfaces without any changes here.
2. New functions: add a new tool module or extend an existing one, register it in server.py.
3. Breaking changes (renamed/removed functions, changed signatures): update the affected tool modules to match the new API, then bump the version pin in pyproject.toml.

To bump the dependency:

# In pyproject.toml, update:
#   "atlasopenmagic>=1.9"  →  "atlasopenmagic>=1.10"

License

Apache-2.0