Swiss Courts Mcp

Part of the Swiss Public Data MCP Portfolio

🏛️ swiss-courts-mcp

[Version] [License: MIT] [Python 3.11+] [MCP] [No Auth Required] [CI]

MCP Server for Swiss court decisions — Federal Supreme Court (BGer), Federal Administrative Court (BVGer), Federal Criminal Court (BStGer), and all 26 cantonal courts via entscheidsuche.ch

Deutsche Version

[Demo: Claude searches Swiss court decisions via MCP tool call]

Overview

Access Swiss court decisions from all judicial levels through a single MCP interface. Combines full-text search with structured filters for canton, court level, date range, and law references.

🎯 Anchor demo query: "Find Federal Supreme Court case law on data protection (Art. 25 DSG) since 2020 — and if entscheidsuche.ch is down, still answer from the offline dump, clearly flagged."

Synergy with fedlex-mcp: Legislation (SR) + case law = complete legal research.

Availability: entscheidsuche.ch is non-profit infrastructure without an SLA. When it is unreachable, the server transparently falls back to a cached public dump (see Offline fallback). Every response declares its origin (source: "live" | "dump"), and dump answers carry a coverage_note — the fallback is partial, not equivalent.

Features

• Full-text search across all Swiss court decisions
• Multi-stage law reference search with regex parser and Elasticsearch boost scoring
• Dedicated Federal Supreme Court search with chamber filter
• Canton and court level filtering
• Recent decisions feed
• Court taxonomy listing
• Decision statistics with aggregations
• Trilingual support (German, French, Italian)
• Offline fallback to a cached public dump when entscheidsuche.ch is unreachable — with explicit provenance on every response
• No API key required

Prerequisites

• Python 3.11 or higher
• An MCP-compatible client (Claude Desktop, Cursor, Windsurf, etc.)

Installation

pip install swiss-courts-mcp

Or install from source:

git clone https://github.com/malkreide/swiss-courts-mcp.gitcd swiss-courts-mcppip install -e ".[dev]"

Quickstart

# Run directlyswiss-courts-mcp
# Or via Python modulepython -m swiss_courts_mcp

Configuration

Claude Desktop

Add to your claude_desktop_config.json:

{  "mcpServers": {    "swiss-courts": {      "command": "python",      "args": ["-m", "swiss_courts_mcp"]    }  }}

Cloud Deployment (HTTP transport)

The HTTP transport is off by default. The default bind host is 127.0.0.1 (loopback only) — 0.0.0.0 must be opted into explicitly (the Dockerfile does this). Running HTTP without authentication logs a warning; only do so behind an authenticating reverse proxy.

# Local HTTP (loopback), no auth — development onlyswiss-courts-mcp --http --port 8000
# Container (binds 0.0.0.0, auth enabled) — see Dockerfiledocker build -t swiss-courts-mcp .docker run -p 8000:8000 -e MCP_AUTH_SECRET="$(openssl rand -hex 32)" swiss-courts-mcp

Relevant environment variables (see .env.example):

Authentication validates the user identity from the JWT sub claim only; see ADR 0001.

MCP_OAUTH_AUDIENCE is mandatory once auth is on. The aud claim is what binds a token to this server. Without it the verifier did not check the audience at all and accepted any correctly signed token from the same issuer — including one minted for a different service (confused deputy). The server now refuses to start in auth mode without it.

MCP_OAUTH_ISSUER is mandatory too, for the same reason on the other side of the token. The iss claim binds a token to the IdP this server trusts. This matters as soon as several tenants share one JWKS URL — the normal case with a hosted IdP: the signature is then valid for all of them, and only iss separates them. Measured with the variable unset, audience correct: a token with iss: https://another-tenant.example was accepted, and so was a token with no iss at all. The value is compared literally per RFC 8414/9207, trailing slash included, and is therefore not normalised — unlike MCP_RESOURCE_URL, where a trailing slash is trimmed.

It is also what makes discovery work. authorization_servers[0] in the RFC 9728 document is the value an SDK client adopts as its authorization server. Without the variable the server named itself there — and under that address /.well-known/oauth-authorization-server, /.well-known/openid-configuration, /authorize, /token and /register all answer 404, because this is a resource server, not an authorization server.

MCP_RESOURCE_URL is what an OAuth client needs. Per RFC 9728 the server publishes a resource identifier at /.well-known/oauth-protected-resource and names it in the WWW-Authenticate header of every 401 — that is where a client looks to find out where to get a token. Without the variable the server publishes its bind address; measured with a container bind, that was {"resource": "http://0.0.0.0:8000", …}, an address no client can dial. Set it on any non-loopback bind; the server warns at startup when it is missing.

The SDK's own validate_token_resource stays off for a measured reason: it compares the token's resource indicator literally against resource_server_url, which here is the bind address. A token whose audience is not that exact URL is rejected with 401 — so switching it on would lock out every real client while the audience check above is what actually protects the server.

Offline fallback (env)

Pre-warm the cache (downloads the ~120 MB SCD CSV once, so the first real outage does not pay the download cost):

SWISS_COURTS_FORCE_DUMP=1 python -m swiss_courts_mcp  # then issue one search

MCP Protocol Versions

The server serves two protocol eras over the same endpoint; the client's first request decides which one it gets:

Both revisions are pinned and both have a drift guard against the installed SDK, so a protocol bump stays a conscious change (constant + CHANGELOG + this section). SDK updates land monthly via Dependabot.

Spec 2026-07-28 is the era the SDK's own client picks. mcp.Client probes server/discover and only falls back to the handshake if that is refused; against this server it does not fall back. Measured through the assembled ASGI stack in tests/test_modern_era.py, not inferred from constant names.

What differs in the modern era:

• No initialize, no session ID. Every POST is self-contained and carries params._meta with the protocol version and the client capabilities, plus the routing headers MCP-Protocol-Version, Mcp-Method and (for tools/call, prompts/get, resources/read) Mcp-Name.
• server/discover replaces the handshake for capability discovery, and subscriptions/listen replaces the change notifications.
• ping, logging/setLevel and the resources/subscribe pair are gone. In this era the server answers them with -32601; in the legacy era they remain.
• ttlMs / cacheScope ride on the listing methods (SEP-2549) — see CACHE_HINTS.
• serverInfo is stamped into the _meta of every response, because there is no handshake to carry it once. It names the build version, the display title and the project URL; the purpose text stays in instructions, which travels once with server/discover.

An initialize asking for 2026-07-28 still gets 2025-11-25 back: the handshake is not the way into the modern era, and that answer says nothing about whether the server speaks it.

Project Phase

Phase 1 — read-only (see ROADMAP.md). All tools are readOnlyHint: true; there are no writing or destructive operations. A move to Phase 2 (write) requires a clean re-audit and the gates listed in the roadmap.

Available Tools

Court Decision Search

Court Information

Tool Annotations

All eight tools share the same hints — they are read-only, idempotent, non-destructive, and reach an external system:

A rechtsrecherche prompt is also provided (a second MCP primitive alongside tools).

Example Use Cases

→ More use cases by audience →

Architecture

┌─────────────────────────────────────┐│         MCP Client (LLM)            ││   Claude / Cursor / Windsurf        │└──────────────┬──────────────────────┘               │ MCP Protocol┌──────────────▼──────────────────────────────┐│              swiss-courts-mcp               ││  8 tools · Pydantic validation              ││  Elasticsearch query builder                ││  Provenance envelope: source = live | dump  │└───────┬──────────────────────────────┬──────┘        │ ① live (default)             │ ② fallback        │ HTTPS POST/GET               │ on bot-block / 5xx / 429 /        │                              │ timeout, or SWISS_COURTS_FORCE_DUMP=1┌───────▼──────────────────┐   ┌───────▼───────────────────────────────┐│     entscheidsuche.ch    │   │   SCD dump — Zenodo 14867950 (CC BY)  ││  Elasticsearch backend   │   │   lazy download → platformdirs cache  ││  Federal + 26 cantons    │   │   → local SQLite search               ││  no auth · no SLA        │   │   BGer only · 2007–2024 · no full text │└──────────────────────────┘   └───────────────────────────────────────┘

Live-first, always: the offline dump only engages on an availability failure (bot-block, HTTP 5xx/429, timeout) or when forced. It is a behaviour of the existing tools, not a separate search tool — why this source and not the full-text one is in ADR 0002; what it does and does not cover is under Known Limitations. Inspect the cache at any time with get_fallback_status.

Safety & Limits

Known Limitations

• Search is limited to decisions indexed by entscheidsuche.ch (not all decisions are publicly available)
• Full-text document content is not returned — only metadata, title, and abstract
• Statistics depend on Elasticsearch aggregation support of the backend
• The court taxonomy structure from Facetten_alle.json may vary

Offline fallback (partial coverage — read this): the fallback is a safety net for availability, not an equivalent mirror of the live source:

• Court scope: Federal Supreme Court only (BGer/BGE). Bundesverwaltungsgericht, Bundesstrafgericht and all 26 cantonal courts are not covered.
• Time span: 2007 – December 2024 (the SCD dump's range). Decisions outside this window are not in the dump.
• Content: metadata/regesten only — no full text offline.
• Update latency: the SCD dump is refreshed roughly quarterly on Zenodo, so the offline data lags the live index. get_fallback_status reports the cached version and can check Zenodo for a newer one.
• Law-reference search offline only matches references named in the decision's subject/regest (topic/issue) — there is no offline cited-law index.
• get_court_decision is best-effort offline: SCD case ids (docref, e.g. 1C_517/2016) differ from entscheidsuche signatures, so some lookups are honestly reported as non-resolvable.
• Responses always disclose their origin via source (live/dump) and a coverage_note; the server never silently narrows coverage — an uncovered query gets an explicit "not covered" answer, never a silent empty result.

Testing

Unit tests mock all HTTP with respx. Run from the project root. The five gates CI runs — check_gate_docs.py holds this list against ci.yml, so it cannot quietly fall behind:

PYTHONPATH=src pytest tests/ -m "not live"python scripts/check_ruff_pin.pyruff check src/ tests/ scripts/ruff format --check src/ tests/ scripts/python scripts/check_version_sync.pypython scripts/check_gate_docs.py

The live tests are not a gate — they hit the real source and run on a schedule (live.yml), not on pull requests:

PYTHONPATH=src pytest tests/ -v -m live

Editing live.yml is a special case: GitHub only honours schedule on the default branch, so changes take effect after the merge — trigger it by hand (workflow_dispatch) to test them before that.

The offline-fallback tests mock the Zenodo download with respx and use a small committed fixture — the ~120 MB dump is never downloaded in CI.

Changelog

See CHANGELOG.md.

Contributing

See CONTRIBUTING.md.

Security

See SECURITY.md for the security posture and how to report a vulnerability.

License

MIT

Author

Hayal Oezkan · malkreide

Credits & Related Projects

• entscheidsuche.ch — Swiss court decision search engine (live source)
• Swiss Federal Supreme Court Dataset (SCD) — offline fallback source, CC BY 4.0: Geering, F. & Merane, J. (2025). Swiss Federal Supreme Court Dataset (SCD), Version 2024-3. Zenodo. https://doi.org/10.5281/zenodo.14867950
• fedlex-mcp — MCP Server for Swiss federal law (legislation synergy)
• zurich-opendata-mcp — MCP Server for Zurich open data
• Model Context Protocol — Open protocol for AI tool integration

Installation

Run via uv's uvx — no clone or manual install needed. Add to your MCP client config (mcpServers for Claude Desktop, Cursor and Windsurf; use a top-level servers key for VS Code in .vscode/mcp.json):

{  "mcpServers": {    "swiss-courts-mcp": {      "command": "uvx",      "args": [        "swiss-courts-mcp"      ]    }  }}