legal-text-mcp-de 2.0.0

Python MCP server and HTTP API for loading, validating, searching, and resolving German legal texts with source provenance.

legal-text-mcp-de

MCP-native research agent for German federal + state law, with HTTP API as secondary surface.

It is local or server-side infrastructure: no SaaS, no billing, no accounts, no tenant model, and no legal advice. The runtime loads either the committed fixture packages used by fast CI or a generated production corpus package built outside Git. Official text comes from gesetze-im-internet.de for German federal laws and from EUR-Lex / Cellar for EU acts such as the GDPR.

No legal advice. This software returns text and structured metadata. It does not interpret the law, advise on it, or produce any legal conclusion. The maintainer assumes no liability for use in legal decision-making contexts.

Older internal documentation has been archived under docs-legacy/summary.md.

Status

Lifecycle	Stable v2.0.0 GA — MCP-native domain server
Versioning	SemVer 2.0.0 (stability contract starts at v1.0.0)
Licence	Apache License 2.0 — see LICENSE and NOTICE
Upstream	Derived from floleuerer/deutsche-gesetze-mcp (MIT, preserved)

Features

• MCP tools for listing laws, fetching norms, resolving citations, full-text search, and source provenance.
• HTTP API (FastAPI) over the same runtime, with structured /health, /ready, /laws, /search, and OpenAPI endpoints.
• Provenance-first design: every law and norm carries source URL, fetch timestamp, content hash, and the parser path it traversed.
• Two corpus modes: committed fixture packages for deterministic tests and CI, or a generated production package built from official sources at runtime.
• No editorial bundling: this repository ships tooling, not legal text. Texts are loaded from official sources at runtime.

Installation

Mode 1 — uvx + auto-download (default, easiest)

uvx legal-text-mcp-de

Server fetches the latest signed corpus bundle from GHCR on first run.

Mode 2 — Docker with pre-bundled corpus

docker run -p 8001:8001 ghcr.io/klein-business/legal-text-mcp-de-full:2.0.0

Mode 3 — Self-built corpus (compliance-sensitive)

git clone https://github.com/klein-business/legal-text-mcp-de
cd legal-text-mcp-de
uv run python -m prepare_data.build_corpus --output ./my-corpus.tar.zst --sources land:by,land:nrw
DATASET_PATH=./my-corpus.tar.zst uvx legal-text-mcp-de

Mode 4 — Public-hosted service

// claude_desktop_config.json
{
  "mcpServers": {
    "legal-de": {
      "url": "https://mcp.klein.business/legal/de",
      "transport": "streamable-http"
    }
  }
}

Quickstart

Run the MCP server with the committed fixture corpus

uv sync --all-groups

DATASET_PATH=tests/fixtures/normalized \
STRICT_STARTUP=true \
uv run legal-text-mcp-de

The default transport is streamable HTTP at http://localhost:8001/mcp.

Run the HTTP API

DATASET_PATH=tests/fixtures/normalized \
STRICT_STARTUP=true \
uv run uvicorn legal_text_mcp_de.http_api:app --host 127.0.0.1 --port 8080

Docker

The Docker image does not bundle legal text data. Mount a validated package at /data/legal-texts:

docker run --rm -p 8001:8001 \
  -v /path/to/legal-text-package:/data/legal-texts:ro \
  ghcr.io/klein-business/legal-text-mcp-de:2.0.0

MCP Resources

v2.0 exposes the corpus as read-only legal:// URIs that any MCP client can load directly into its LLM context. Examples:

• legal://laws — paginated index
• legal://laws/bgb — BGB header + norm index
• legal://laws/bgb/norms/par:433 — § 433 BGB as Markdown
• legal://corpus/coverage — what's in the corpus

See docs/concepts/mcp-native.md for the full URI catalogue.

MCP Prompts (slash-commands)

Five curated workflows appear as slash-commands in MCP clients:

Slash	Args	Purpose
/rechtsfrage	frage, rechtsgebiet?	Answer a German legal question with exact norm citations
/zitation-checken	citation	Resolve a citation (e.g. § 433 Abs. 1 BGB) + Stand-Datum
/norm-erklaeren	code, norm	Plain-language explanation with cited cross-references
/recherche	topic	Multi-step research using research_topic smart tool
/dsgvo-check	aktivitaet	Walk through GDPR Art. 5, 6, 7, 9, 13, 14 against a processing activity

Smart Tools

research_topic is a multi-step research tool that orchestrates 2 LLM-sampling calls per invocation:

1. Corpus search for candidate norms
2. LLM ranking of candidates by relevance
3. Related-norms graph loading
4. LLM synthesis of a structured research report

When the client lacks sampling support, the tool returns a degraded report with ranked candidates only.

Data Sources

Source	Coverage	Reuse position
gesetze-im-internet.de	German federal laws	Public-domain-equivalent under §5 (1) UrhG
EUR-Lex / Cellar (publications.europa.eu)	EU acts (GDPR, AI Act, Data Act, …)	Reuse permitted under Commission Decision 2011/833/EU with attribution

No text from these sources is committed to this repository. The generated-corpus pipeline fetches them at build time and stores provenance in a manifest.

MCP Tools

See the MCP tools reference for the full surface. Highlights:

• list_laws(query?) — list loaded laws with optional metadata filter.
• get_law(code) — law metadata + normalised norm summaries.
• get_norm(code, norm) — return one structured norm.
• search_laws(query, codes?) — search normalised texts.
• resolve_citation(...) — resolve structured citations without legal interpretation.
• get_source_metadata(code?), get_source_limitations(...), get_corpus_coverage(), get_related_norms(code, norm).

MCP tools return JSON-compatible objects. They do not return double-serialised JSON strings.

HTTP API

Method	Path	Purpose
GET	/health	Liveness
GET	/ready	Readiness
GET	/laws	List laws
GET	/laws/{code}	Law detail
GET	/laws/{code}/norms/{norm}	Norm detail
GET	/laws/{code}/norms/{norm}/relationships	Relationship metadata
GET	/corpus/coverage	Corpus coverage summary
GET	/corpus/source-limitations	Source limitations query
GET	/search	Search
GET	/openapi.json	OpenAPI document

Article-plus-section paths must be URL-encoded:

/laws/egbgb/norms/art%3A246a%2Fpar%3A1

Documentation

Full documentation is published at klein-business.github.io/legal-text-mcp-de.

Quick links:

• Quickstart
• MCP tools
• HTTP API
• Operations: security, SBOM, cosign-verify, versioning, threat model
• Roadmap

Source-of-truth documents live in the repo: README.md, CHANGELOG.md, SECURITY.md, CONTRIBUTING.md, GOVERNANCE.md, NOTICE, LICENSE.

Development

uv sync --all-groups
PYTHONPATH=mcp uv run --group dev pytest mcp/tests -v

The full fixture-backed release gate:

PYTHONPATH=mcp uv run --group dev python scripts/verify_release.py

The public-flip readiness gate:

PYTHONPATH=mcp uv run --group dev python scripts/verify_pre_flip.py

Contributing

See CONTRIBUTING.md for guidelines, code of conduct, and security policy. All contributions must comply with the Developer Certificate of Origin (sign-off with git commit -s).

Verification (post-v2.0.0)

Each release is signed and accompanied by an SBOM and SLSA-3 provenance.

Cosign image signature

cosign verify ghcr.io/klein-business/legal-text-mcp-de:2.0.0 \
  --certificate-identity-regexp 'https://github.com/klein-business/.*' \
  --certificate-oidc-issuer https://token.actions.githubusercontent.com

See Verify with cosign for SBOM and SLSA attestation verification.

Licence and acknowledgements

This project is licensed under the Apache License 2.0. See NOTICE for required attribution.

Derived from floleuerer/deutsche-gesetze-mcp (Copyright (c) 2025 Florian Leuerer, MIT). Upstream licence terms are preserved in licenses/MIT-floleuerer.txt.