Public Transport Belgium MCP

A remote MCP server for Belgian public transport, running on Cloudflare Workers. Add it to Claude (web, desktop or phone) as a custom connector and ask things like:

• "Is the 08:04 from Brussels-Midi to Gent on time, and which platform?"

• "When is the next metro at Arts-Loi?"

• "Which bus from Gent Sint-Pietersstation gets me to Gent Zuid, and when does it arrive?"

• "Any disruptions on the SNCB today?"

TEC (Wallonia) is not supported yet.

Tools

Output is compact text, one line per item, designed to be cheap for the model to read. The server stores no personal data: no accounts, no favourites, no history.

Related MCP server: Porto Alegre MCP Server LLM Bus

Deploy your own

You need a free Cloudflare account and Node.js 20+.

git clone https://github.com/sebasvermeir-sys/Belgium-Public-Transport-MCP.git
cd Belgium-Public-Transport-MCP
npm install
npx wrangler login
npx wrangler kv namespace create CACHE   # paste the printed id into wrangler.jsonc

Edit wrangler.jsonc:

• kv_namespaces[0].id: the id from the command above.

• IRAIL_USER_AGENT: your own app name and contact (iRail asks for this).

Set the secrets. Each command prompts for the value, so it never lands in your shell history or in git:

npx wrangler secret put MCP_TOKEN              # required: a long random password, e.g. from `openssl rand -hex 32`
npx wrangler secret put BELGIAN_MOBILITY_KEY   # optional: enables STIB
npx wrangler secret put DELIJN_API_KEY         # optional: enables De Lijn
npx wrangler secret put APP_TOKEN              # optional: see "Structured output" below

Then:

npm run deploy

Getting the API keys

• STIB: sign up at the Belgian Mobility open data portal, subscribe to the STIB product and copy the subscription key.

• De Lijn: sign up at portal.delijn.be, subscribe to "Open Data Free" and copy the primary key.

Without these keys the server still works for SNCB; the STIB or De Lijn tools say they're not configured.

Connect it to Claude

In claude.ai: Settings → Connectors → Add custom connector.

• URL: https://<your-worker>.workers.dev/mcp

• Request header (if your account offers it): Authorization: Bearer <MCP_TOKEN>

• Otherwise use the URL https://<your-worker>.workers.dev/mcp/<MCP_TOKEN>. This puts the token in the URL, so only use it where headers aren't available.

Any other MCP client that speaks Streamable HTTP works the same way.

Structured output (optional)

Callers using APP_TOKEN instead of MCP_TOKEN get the same text plus structuredContent with a declared outputSchema (schema version "1"): ISO times with the Brussels offset, stops with coordinates, time objects {scheduled, expected, delay_min, realtime}, and stable disruption ids. This is meant for apps and dashboards. The chat token stays text-only because the structured data is several times larger. The schemas live in src/structured.ts.

Development

cp .dev.vars.example .dev.vars   # fill in at least MCP_TOKEN; never commit .dev.vars
npm run dev                      # local server on http://localhost:8787/mcp
npm test                         # vitest: runs the real Worker against recorded fixtures with a fixed clock
npm run typecheck
npm run profile                  # CPU time per tool

• Text output is locked by test/snapshot.test.ts. Update snapshots (npx vitest run -u) only for deliberate format changes.

• Recorded upstream responses are in test/fixtures/.

Notes

• Free plan CPU: Workers Free allows 10 ms of CPU per request. Warm requests fit, but the first request on a fresh instance can go over and fail. The Workers Paid plan ($5/month) removes this.

• Stop lists (about 715 SNCB stations and 870 STIB stops) are rebuilt into KV by a cron every 6 hours. De Lijn stops are looked up through its search API on demand.

• Caching: responses are cached for 20–60 s, with a 10-minute stale copy served if an upstream API fails.

• iRail allows 3 requests per second per IP. The server throttles itself below that.

Data sources

Train data from iRail (community API on top of NMBS/SNCB open data). STIB data from the Belgian Mobility open data portal. De Lijn data from the De Lijn open data portal. Check each provider's terms before running a public instance. This project is not affiliated with SNCB, STIB, De Lijn or iRail.

License

MIT