Sl MCP Server

sl-mcp

An MCP server for Stockholm public transport (SL). Connect it to Claude or another MCP client and ask about departures, disruptions and trips in plain Swedish or English.

När går nästa tunnelbana från Slussen mot Ropsten?
Är det några störningar på röda linjen?
How do I get from Odenplan to Arlanda?
Hur tar jag mig från Sundbyberg till Götgatan 76?

It uses SL's open APIs, which don't need an API key.

An answer looks like this:

Gå 08:31 från Sundbybergs centrum, så är du framme på Götgatan 76 kl 08:58.

1. 08:31 Tunnelbana 10 mot Kungsträdgården från spår 2. Åk 7 stationer till T-Centralen.
2. 08:47 Byt till tunnelbana 17 mot Skarpnäck från spår 4. Åk 3 stationer till Medborgarplatsen.
3. 08:52–08:58 Gå ut via uppgång Folkungagatan Götgatan och gå 6 min till Götgatan 76.

Use it without installing

A hosted server runs on Cloudflare Workers. No API key or login is needed:

https://sl-mcp.miltonlindblad.workers.dev/mcp

Add it as a custom connector in claude.ai or ChatGPT, or in any MCP client that supports Streamable HTTP. In Claude Code:

claude mcp add --transport http sl https://sl-mcp.miltonlindblad.workers.dev/mcp

Tools

• find_stop: search for a stop by name, typos are fine, and get its id
• get_departures: live departures from a stop with platform or bus stop letter, delays and cancellations. Filter by mode, line or destination
• get_disruptions: announced disruptions such as track work, broken lifts and replacement buses, by line, mode or metro colour ("grön linje")
• plan_trip: up to 3 trips between stops or street addresses, leaving or arriving at a given time. Each ride shows platform, stops, crowding and delay, and each walk shows minutes and which station exit to use. You can ask for only some modes (e.g. boat) and for fewest changes or least walking

Prompts

Ready-made questions to pick in your client, e.g. as slash commands:

• trip: how to get from one place to another, optionally arriving by a given time
• departures: the next departures from a stop

Install

Requires Node.js 20 or later.

git clone https://github.com/Hashtagsmile/sl-mcp.git
cd sl-mcp
npm install
npm run build

Claude Code

claude mcp add sl -- node /path/to/sl-mcp/dist/index.js

Claude Desktop

Add this to claude_desktop_config.json and restart Claude Desktop:

{
  "mcpServers": {
    "sl": {
      "command": "node",
      "args": ["/path/to/sl-mcp/dist/index.js"]
    }
  }
}

Development

npm run dev       # compile on save
npm test          # run the tests
npm run inspect   # try the tools in the MCP Inspector

The tests use recorded API responses in test/fixtures/, so they don't call SL.

Deploy to Cloudflare Workers

src/worker.ts serves the same tools over HTTP at /mcp.

npx wrangler dev      # run it locally on http://localhost:8787/mcp
npx wrangler deploy   # deploy to your Cloudflare account

Limitations

• SL returns at most 3 departures per line and direction.
• Disruption messages are in Swedish only.
• There is no "nearest stop" search, since SL has no keyless API for it.
• SL can't plan step-free trips. For a wheelchair, the tools suggest least walking and checking for broken lifts.
• Addresses work, business names don't: "Götgatan 76" works, "Sellpy" doesn't.
• Departures reach at most 3 hours ahead. For later, use plan_trip with a time.

Data

Data from SL via Trafiklab.

License

MIT