Fedlex MCP Server

:switzerland: Part of the Swiss Public Data MCP Portfolio

:balance_scale: fedlex-mcp

MCP Server for Swiss federal law — search the SR, monitor legal changes, and query BBl/treaties via Claude Desktop or Claude.ai

:de: Deutsche Version

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Overview

fedlex-mcp connects AI assistants (Claude) with the Fedlex SPARQL endpoint of the Swiss Federal Chancellery. This enables AI agents to look up Swiss federal law, monitor legal changes, and analyse legislation directly in conversation — without manual research on fedlex.admin.ch.

Metaphor: USB-C for federal law. Once connected, Claude can reach into the Systematic Compilation at any time.

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Features

• :balance_scale: 7 tools, 2 resources covering the full breadth of Swiss federal law
• :mag: SPARQL-powered — direct access to the Fedlex linked data endpoint
• :globe_with_meridians: 4 languages — German, French, Italian, Romansh
• :unlock: No API key required — all data under open reuse licence
• :cloud: Dual transport — stdio (Claude Desktop) + Streamable HTTP (cloud)

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Prerequisites

• Python 3.11+
• uv (recommended) or pip

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Installation

# Clone the repository
git clone https://github.com/malkreide/fedlex-mcp.git
cd fedlex-mcp

# Install
pip install -e .
# or with uv:
uv pip install -e .

Or with uvx (no permanent installation):

uvx fedlex-mcp

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Quickstart

# stdio (for Claude Desktop)
python -m fedlex_mcp.server

# Streamable HTTP (port 8000)
python -m fedlex_mcp.server --http --port 8000

Try it immediately in Claude Desktop:

"Show me all valid federal laws on vocational training" "What does the Data Protection Act say? Is it still in force?" "Which federal laws enter into force in the next 3 months?"

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Configuration

Claude Desktop

Edit ~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or %APPDATA%\Claude\claude_desktop_config.json (Windows):

{
  "mcpServers": {
    "fedlex": {
      "command": "python",
      "args": ["-m", "fedlex_mcp.server"]
    }
  }
}

Or with uvx:

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

Config file locations:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json

Cloud Deployment (SSE for browser access)

For use via claude.ai in the browser (e.g. on managed workstations without local software):

Render.com (recommended):

1. Push/fork the repository to GitHub
2. On render.com: New Web Service -> connect GitHub repo
3. Set start command: python -m fedlex_mcp.server --http --port 8000
4. In claude.ai under Settings -> MCP Servers, add: https://your-app.onrender.com/sse

"stdio for the developer laptop, SSE for the browser."

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Demo

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Available Tools

Example Use Cases

→ More use cases by audience →

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Architecture

+-------------------+     +------------------------------+     +--------------------------+
|   Claude / AI     |---->|  Fedlex MCP                  |---->|  Fedlex SPARQL Endpoint  |
|   (MCP Host)      |<----|  (MCP Server)                |<----|  (Swiss Federal          |
+-------------------+     |                              |     |   Chancellery)           |
                          |  7 Tools . 2 Resources       |     +--------------------------+
                          |  Stdio | SSE                 |
                          |                              |
                          |  No authentication required  |
                          +------------------------------+

Data Model (JOLux Ontology)

jolux:ConsolidationAbstract  <-  SR entry
  +-- jolux:isRealizedBy  ->  jolux:Expression (URI ends in /de, /fr, /it, /rm)
     +-- jolux:title               "Federal Act of 19 June 1992 on Data Protection"
     +-- jolux:titleShort          "DSG"
     +-- jolux:historicalLegalId   "235.1"

jolux:inForceStatus:
  .../0  In force
  .../1  No longer published in the SR
  .../3  No longer in force

SPARQL Endpoint: https://fedlex.data.admin.ch/sparqlendpoint Licence: Free reuse (commercial and other purposes) per fedlex.admin.ch

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Languages

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Project Structure

fedlex-mcp/
+-- src/fedlex_mcp/
|   +-- __init__.py              # Package
|   +-- server.py                # 7 tools, 2 resources
+-- tests/
|   +-- test_server.py           # Unit tests (mocked)
+-- .github/workflows/ci.yml     # GitHub Actions (Python 3.11/3.12/3.13)
+-- pyproject.toml
+-- CHANGELOG.md
+-- CONTRIBUTING.md               # Contributing guide (English)
+-- CONTRIBUTING.de.md            # Contributing guide (German)
+-- SECURITY.md                   # Security policy (English)
+-- SECURITY.de.md                # Security policy (German)
+-- LICENSE
+-- README.md                    # This file (English)
+-- README.de.md                 # German version

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Known Limitations

• SPARQL complexity: Very broad keyword searches may time out (45s timeout)
• Language coverage: German has the most complete data; other languages may have gaps
• Historical data: Not all historical versions of laws have machine-readable metadata
• Rate limiting: The Fedlex endpoint may throttle high-frequency requests

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Project Phase

This server is in Phase 1 (read-only). All tools are annotated readOnlyHint: true / destructiveHint: false and only ever query the public Fedlex SPARQL endpoint — there are no write, send, or filesystem capabilities.

A transition to a later phase would require an audit re-run and the human-in-the-loop controls described in the audit catalog before any write-capable tool is added.

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MCP Protocol Version

The protocol version is negotiated at the initialize handshake by the mcp Python SDK (pinned to >=1.3.0 in pyproject.toml). The SDK is kept current via monthly Dependabot PRs (.github/dependabot.yml); protocol-relevant bumps are noted in CHANGELOG.md.

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Testing

# Unit tests (no API key required)
PYTHONPATH=src pytest tests/ -m "not live"

# Integration tests (live API calls)
pytest tests/ -m "live"

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Safety & Limits

• Read-only: All tools perform SPARQL SELECT queries only — no data is written, modified, or deleted on the Fedlex endpoint.
• No personal data: Fedlex contains public law texts and official gazettes. No personally identifiable information (PII) is processed or stored by this server.
• Rate limits: The Fedlex SPARQL endpoint is a public service without a documented rate limit; use limit parameters conservatively. The server enforces a 45s timeout per request.
• Data freshness: Results reflect the Fedlex endpoint at query time. No caching is performed by this server.
• Terms of service: Data is subject to the reuse conditions of fedlex.admin.ch — free reuse for commercial and other purposes.
• No guarantees: This server is a community project, not affiliated with the Swiss Federal Chancellery. Availability depends on the upstream SPARQL endpoint.

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Changelog

See CHANGELOG.md

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Security

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

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Contributing

See CONTRIBUTING.md

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License

MIT License — see LICENSE

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Author

Hayal Oezkan . malkreide

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Credits & Related Projects

• Fedlex: fedlex.admin.ch — Swiss Federal Chancellery
• Protocol: Model Context Protocol — Anthropic / Linux Foundation
• Related: swiss-cultural-heritage-mcp — Swiss cultural heritage data
• Related: zurich-opendata-mcp — City of Zurich open data
• Related: swiss-transport-mcp — Swiss public transport
• Portfolio: Swiss Public Data MCP Portfolio

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": {
    "fedlex-mcp": {
      "command": "uvx",
      "args": [
        "fedlex-mcp"
      ]
    }
  }
}