marta-mcp

An MCP server for Atlanta MARTA real-time transit data. Ask Claude things like "When's the next northbound Red Line train at Midtown?" or "Where are the buses on route 110 right now?"

Tools

Tool	Data source	API key?
get_rail_arrivals	Rail real-time RESTful API — arrival predictions for every station, filterable by station / line / direction	Yes
list_rail_stations	Static — canonical station names	No
get_bus_positions	GTFS-realtime vehicle positions feed (protobuf)	No
get_bus_trip_updates	GTFS-realtime trip updates feed (protobuf)	No

API key setup

Rail data requires a free MARTA API key — register here.

The key is never stored in this project or in your MCP client config. The server reads it from, in order:

1. The MARTA_API_KEY environment variable

2. ~/.marta/config.json:

   { "api_key": "your-key-here" }
   

The easiest way to create the config file:

uvx --from git+https://github.com/LordPsycho202/marta-mcp marta-mcp-config <your-key>

Installation

Option 1 — Claude Desktop extension (one-click)

Requires uv to be installed.

Download marta-mcp.dxt (or .mcpb — same file, newer name) from the latest release and double-click it, or drag it into Claude Desktop's Settings → Extensions. No JSON editing needed.

The extension is a thin manifest: Claude Desktop launches the server with uvx --from git+<this repo>, fetching the package and its dependencies on first run — so it works on any OS and always tracks the repo's main branch.

Build it yourself (requires Node.js):

bash scripts/build_dxt.sh          # macOS / Linux
powershell -ExecutionPolicy Bypass -File scripts\build_dxt.ps1   # Windows

Option 2 — uvx straight from GitHub

Add to your MCP client config (e.g. claude_desktop_config.json):

{
  "mcpServers": {
    "marta": {
      "command": "uvx",
      "args": ["--from", "git+https://github.com/LordPsycho202/marta-mcp", "marta-mcp"]
    }
  }
}

Option 3 — local clone

git clone https://github.com/LordPsycho202/marta-mcp
cd marta-mcp
uv run marta-mcp

Development

uv sync
uv run pytest          # live smoke tests against MARTA's APIs

Notes

• Bus route_id values are MARTA's internal GTFS identifiers, which don't always match the public route numbers. Pair this server with MARTA's static GTFS feed if you need the mapping.
• This project is not affiliated with or endorsed by MARTA. MARTA's marks may not be used without written authorization.

License

MIT