Swiss Grounding MCP

Answers about Switzerland, with the source.

An MCP server that grounds AI assistants in official federal, cantonal and municipal information,
in German, French, Italian, Romansh and English, and cites the responsible authority in every answer.

Try it live

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Running on Google Cloud Run in Zürich (europe-west6), deployed from main. Public and read-only: no sign-up, no API key. Live server: swiss-grounding-mcp-542630986415.europe-west6.run.app MCP endpoint (Streamable HTTP): https://swiss-grounding-mcp-542630986415.europe-west6.run.app/mcp Health: /health

Add it to an assistant in one line, e.g. Claude Code (other clients):

claude mcp add --transport http swiss https://swiss-grounding-mcp-542630986415.europe-west6.run.app/mcp

It scales to zero when idle, so the first request after a pause starts an instance (about 2 s; hybrid search follows about 10 s later, keyword search answers meanwhile). It is rate-limited per client, refuses browser origins and is checked every 6 hours. The hosted instance runs the code in this repository, which also runs locally.

How it works

_{The example is sample question 3 of the challenge brief, answered by the live server.}

Ask a general-purpose assistant about Switzerland and it may answer for the wrong canton, from an outdated page or from a neighbouring country. Swiss Grounding MCP gives it the responsible authority's own data instead:

1. One tool call. The assistant picks one of 13 read-only tools. Places work as people write them: Genf, Ginevra, Genève, Schuls → Scuol, 8003, Bahnhofstrasse 1, Zürich.
2. The right authority. Answers come from the level that is responsible (federal office, canton or municipality), through a prebuilt index of 10,630 official pages (keyword + multilingual semantic search), live federal APIs and municipal open data.
3. Polite and resilient. robots.txt and terms of use are respected by default, requests are paced and cached, and when a source is down a dated copy is served or the source is named.
4. One cited answer. Every tool returns the same contract, with verbatim excerpts and one of five statuses that tell the assistant what to do:

Coverage

The declared scope: what the server answers, for which area, from which authority. Assistants can read it too, with the swiss_coverage tool.

Not covered, and known limits

• Anything outside Switzerland, e.g. the German Rundfunkbeitrag in Konstanz: the server says so.
• Cantons GR, BL and SH block or do not serve text to automated clients, so their cantonal pages are not in the index (ch.ch and federal pages still apply; read_official_page reports the block honestly). VS (7 pages), TI (45) and TG (52) are only partly indexed.
• Municipal web pages are indexed for the nine cities above (120–250 pages each; Lausanne 66, Thun 32). Zürich has only a few pages, Bellinzona and Fribourg none yet (the next refresh crawls Fribourg's own domain, ville-fribourg.ch). For other municipalities the server returns the official website and can read a given page live.
• Waste calendars exist only where municipalities publish open data; elsewhere the server says so and links the municipality. Holidays, premiums and place facts cover every municipality.
• Cantonal law texts, individual tax calculations and weather forecasts are not provided.
• School holidays come from OpenHolidays, which aggregates official lists. Where the index holds the responsible authority's own calendar (e.g. ge.ch, bern.ch, the school of Scuol), that page is cited first, with the EDK list and the municipality site alongside. Periods are labelled by school type where a canton publishes several (canton Bern: German- and French-speaking schools).
• Registering on arrival in Lausanne is weak: the city's residents' office page is not in the index.
• Cross-language questions: a question in another language than the place's pages first returns a language hint, not the page, and the assistant has to search again. In end-to-end runs of such a question (French, about Bern), Sonnet followed the hint and answered from Bern's page; Haiku did so in 1 of 4 runs.
• Search is keyword-based by default. With the optional semantic extra it is hybrid and also finds pages worded differently or written in another language, but still misses some (measured); Romansh is not covered by the embedding model.

Results

With and without this server. The same 28 questions (the 5 published samples, 12 of our own and the organisers' 11 practice cases), asked to Claude Code with Sonnet three ways that differ only in their tools: