Storstockholms Lokaltrafik (SL) MCP Server

An MCP server for Stockholm's public transit (SL). Gives AI assistants access to real-time departures, trip planning, deviations, and more via SL's open APIs.

Hosted on Runway at https://sl-mcp-server.pqapp.dev

Tools

Tool	What it does
trips	Plan a trip between two locations, with active deviations attached to each leg
departures	Real-time departures from a stop, with in-process filters
deviations	Traffic disruptions, with opt-in facility (lift/escalator) alerts
resolve	Turn a free-text name into a canonical site id (all three forms)
nearest_stops	Find the closest stops to a lat/lon coordinate
stop_finder	Fuzzy name search across stops, addresses, POIs
sites	Enumerate SL's ~6500-entry site catalog with substring filter
lines	Enumerate SL's ~600-entry line catalog with mode / designation filters
stop_points	Individual platforms, quays, and stands within a site
transport_authorities	List transport authorities in the region
system_info	Timetable validity period

Every tool that returns a large payload has a verbose=false default slim shape and a verbose=true escape hatch for the raw upstream data.

Site IDs

SL hands out four id forms for the same stop; all are interchangeable at the server boundary:

• Short form — e.g. 9702 for Jakobsberg. Returned by sites, resolve.best.short_id, nearest_stops.
• 8-digit 18xx form — e.g. 18009702. Returned by stop_finder.properties.stopId, resolve.best.gid_180.
• 9-digit 3BA1CDEFG form — e.g. 300109702. Documented by Trafiklab.
• 16-digit GID — e.g. 9091001000009702. Returned by stop_finder.id, resolve.best.gid_16, and echoed in trips.resolved.

Every tool that takes a site parameter (departures.site_id, deviations.site, trips.origin_id / destination_id) normalizes all four forms. Pass 16-digit GIDs as strings — they exceed JS Number.MAX_SAFE_INTEGER and lose precision if passed as numbers.

trips

Plan a trip between two locations. Returns a trimmed, LLM-friendly summary by default; pass verbose=true for the full upstream payload. Every successful response carries a resolved block echoing the actual origin/destination the planner used so callers can detect silent drift.

Param	Type	Notes
origin	string	Stop/location name. Exactly one of origin / origin_id per side.
origin_id	string	Any site-id form (see above). Bypasses fuzzy name resolution. Prefer this when you have it.
destination	string	Same rules as origin.
destination_id	string	Same rules as origin_id.
number_of_trips	number	1–3, default 3.
time	string	ISO 8601, e.g. 2026-04-22T09:00:00+02:00. Defaults to now.
time_mode	depart | arrive	Default depart. Only meaningful with time.
verbose	bool	Default false. Return the raw upstream response (coords, stopSequence, footpath details).
skip_deviations	bool	Default false. Skip the second /v1/messages call that attaches active deviations to each transit leg.

Trimmed response shape:

{
  "journeys": [
    {
      "duration": 1860,
      "interchanges": 1,
      "summary": "Buss 179 → Pendeltåg 43",
      "departure": "2026-04-21T21:03:00+02:00",
      "arrival": "2026-04-21T21:34:00+02:00",
      "legs": [
        {
          "mode": "bus",
          "line": "179",
          "direction": "Sollentuna station",
          "from": "Vällingby",
          "to": "Spånga station",
          "departure": "2026-

... [View full README on GitHub](https://github.com/henrrrik/sl-mcp-server#readme)