madison-metro-api-proxy

Lightweight proxy for the Madison Metro API service

API Support

The proxy only supports Metro's getpredictions call but with the goal of this service becoming a drop-in replacement for the old SMB API, the endpoint and payload matches that old implementation. Note that I'm also shoving the raw Metro API details into the payload under 'raw_metro'

https://xxxxxxx/v1/getarrivals?key=GET_KEY_FROM_METRO&stopID=METRO_STOP_CODE

{
    "status": "0",
    "timestamp": "10:20AM",
    "stop": {
        "stopID": "1787",
        "route" : [{
            "routeID": "E",
            "vehicleID": "149",
            "human": "Route E toward MCKEE arrives in 4 minutes",
            "minutes": "4",
            "arrivalTime": "10:25 AM",
            "destination": "MCKEE",
            "raw_metro": {
                "tmstmp": "20250316 10:20",
                "typ": "D",
                "stpnm": "S Pinckney at E Main",
                "stpid": "1787",
                "vid": "149",
                "dstp": -38,
                "rt": "E",
                "rtdd": "E",
                "rtdir": "WESTBOUND",
                "des": "MCKEE",
                "prdtm": "20250316 10:25",
                "tablockid": "312E",
                "tatripid": "1217525",
                "origtatripno": "1217525",
                "dly": false,
                "dyn": 0,
                "prdctdn": "4",
                "zone": "",
                "psgld": "",
                "stst": 37500,
                "stsd": "2025-03-16",
                "flagstop": 0
            }
        }]
    }
}

Get started

1. Sign-up for a Metro API developer account here.
2. Send me an email to get the proxy endpoint.

Run Locally

You can run this repo locally with very little configuration.

Setup local Node environment

    > npm install

Run server

    > API_KEY_REGEX="^[a-zA-Z0-9]{25}$" nodemon app-local.js | pino-pretty

API_KEY_REGEX attempts to provide broud support for Metro API keys without needing to track developer keys that are using the proxy.