Rechtsinformationen Bund DE MCP Server

An MCP (Model Context Protocol) server that provides access to the official German Federal Legal Information Portal (rechtsinformationen.bund.de). Any AI agent can use this server for German legal questions to provide authoritative, fact-based answers with proper legal citations from official sources.

🚀 Quick Setup

The fastest way to get started:

1. Run the setup script:

./quick-setup.sh

2. Restart Claude Desktop completely (or your MCP client)

3. Test with: "Wie lange kann ich in Elternzeit gehen?"

🎯 What This Server Provides

AI agents will automatically use this MCP server for:

• German legal questions ("What happens if I miss a Jobcenter appointment?")
• Legal rights and obligations ("How long can I take parental leave?")
• Court decisions and precedents ("Recent BGH decisions on trademark law")
• Specific law lookups ("What does § 32 SGB II say?")
• Administrative law questions ("When do I need a hearing in administrative proceedings?")

Purpose: Ensures all German legal answers are grounded in official sources with proper citations.

✨ Features

Core Capabilities

• Full-text search across German federal laws and legislation
• Case law search through German federal court decisions (BGH, BVerfG, BAG, BFH, BSG, BVerwG)
• Intelligent search with English-to-German translation and misconception correction
• German compound word decomposition (e.g., "Mieterhöhungsantrag" → "Mieterhöhung")
• HTML URLs for users (clickable, readable documents)
• Model-agnostic - works with Claude, Qwen, DeepSeek, LLaMA, and other models

Recent Improvements (2025-10-06)

✅ HTML URLs: Returns human-readable web links, not just JSON API URLs ✅ Compound word handling: Decomposes German compound words for better search ✅ Fallback search: Never returns zero results for valid queries ✅ English translation: Automatically translates English legal terms to German ✅ Type coercion: Works with models that pass strings instead of numbers

📚 Available Tools

The server provides 6 specialized tools with intelligent routing:

1. 🧠 semantische_rechtssuche (PRIMARY TOOL)

Intelligent Legal Search - Use this FIRST for any German legal question

What it does automatically:

• ✓ Translates English → German ("employee rights" → "Arbeitnehmerrechte")
• ✓ Corrects misconceptions ("Überprüfungsantrag" → "Widerspruch")
• ✓ Extracts legal references (§ patterns)
• ✓ Searches multiple related terms
• ✓ Returns both legislation AND case law

What it does NOT do:

• ✗ Does NOT generate semantically similar terms (agent must provide variations)
• ✗ Does NOT try multiple query phrasings automatically
• ✗ Does NOT use ML embeddings (uses keyword matching + Fuse.js fuzzy search)

Parameters:

• query (required): Search query in German or English
• threshold (optional): Fuzzy match threshold 0.0-1.0 (default: 0.3)
• limit (optional): Max results (default: 10, max: 100)

URLs returned:

🌐 READ ONLINE (HTML): https://testphase.rechtsinformationen.bund.de/.../regelungstext-1.html
📊 API ACCESS (JSON): https://testphase.rechtsinformationen.bund.de/v1/legislation/...

2. 🇩🇪 deutsche_gesetze_suchen (SECONDARY TOOL)

Search German federal legislation (laws, ordinances)

When to use:

• Follow-up after semantische_rechtssuche
• Legislation-only results needed
• Searching for specific law abbreviations (BEEG, BGB, SGB)

Limitations: ⚠️ Date filters may exclude relevant results

3. ⚖️ rechtsprechung_suchen (SECONDARY TOOL)

Search German court decisions

When to use:

• Follow-up after semantische_rechtssuche
• Court-specific filtering needed
• Searching for specific judges or case types

Common courts:

• BGH (Federal Court of Justice)
• BVerfG (Constitutional Court)
• BAG (Federal Labour Court)
• BFH (Federal Fiscal Court)
• BSG (Federal Social Court)
• BVerwG (Federal Administrative Court)

4. 🔍 alle_rechtsdokumente_suchen (SECONDARY TOOL)

Comprehensive search across all document types

When to use:

• After other specialized tools
• Mixed results needed (legislation + case law)
• Broad topic exploration

5. 📄 dokument_details_abrufen (RETRIEVAL TOOL)

Get full text of specific documents

When to use:

• After finding document in search results
• Need complete document text (searches only return snippets)
• Want HTML or XML format

6. 🏛️ gesetz_per_eli_abrufen (RETRIEVAL TOOL)

Get legislation by ELI identifier

When to use:

• Have specific ELI from search results
• Need exact version/date of legislation

🤖 Model Compatibility

Tested & Working

• ✅ Claude 3.5 Sonnet - Excellent tool selection, proper citations
• ✅ Qwen 2.5-72B - Best open-source option, good German support
• ✅ DeepSeek-R1 - Strong reasoning, needs recursion limit
• ✅ LLaMA 3.3-70B - Reliable, good for straightforward queries
• ✅ GLM-4.6 - Works with type coercion fixes

Recommended Agent Configuration (LibreChat)

For best results with any model:

{
  "name": "German Legal Research Assistant",
  "description": "Searches official German legal database",
  "model": "qwen2.5:72b",
  "tools": [
    "mcp__rechtsinformationen__semantische_rechtssuche",
    "mcp__rechtsinformationen__deutsche_gesetze_suchen",
    "mcp__rechtsinformationen__rechtsprechung_suchen"
  ],
  "recursionLimit": 5,
  "temperature": 0.3,
  "instructions": "CRITICAL: Always use semantische_rechtssuche FIRST. If search returns results, STOP immediately and generate answer. Maximum 2-3 tool calls total. MUST include ALL URLs in 'Quellen:' or 'Sources:' section."
}

Key settings:

• recursionLimit: 5 - Prevents endless searching
• temperature: 0.3 - More deterministic for legal queries
• Stop condition - Generate answer immediately after finding results

📦 Installation

Quick Setup

git clone <repo-url>
cd rechtsinformationen
./quick-setup.sh

Manual Installation

npm install
npm run build
npm test  # Should show passing tests

Claude Desktop Configuration

macOS: Edit ~/Library/Application Support/Claude/claude_desktop_config.json

{
  "mcpServers": {
    "rechtsinformationen": {
      "command": "node",
      "args": ["/absolute/path/to/rechtsinformationen/dist/index.js"]
    }
  }
}

Windows: Edit %APPDATA%/Claude/claude_desktop_config.json

{
  "mcpServers": {
    "rechtsinformationen": {
      "command": "node",
      "args": ["C:\\absolute\\path\\to\\rechtsinformationen\\dist\\index.js"]
    }
  }
}

Important:

• Use absolute paths (not relative like ./dist/index.js)
• Restart Claude Desktop completely after config changes
• Run npm run check-config to verify setup

LibreChat Agent Configuration

For optimal performance with LibreChat and Ollama models (Qwen, DeepSeek, LLaMA):

{
  "name": "German Legal Research Assistant",
  "model": "qwen2.5:72b",
  "provider": "ollama",
  "recursionLimit": 5,
  "temperature": 0.3,
  "instructions": "CRITICAL RULES:\n- MAXIMUM 2-3 tool calls per query\n- STOP searching after finding 3+ relevant documents\n- ALWAYS include URLs in 'Quellen' section\n- Use semantische_rechtssuche first\n\nCitation Format (MANDATORY):\n## Quellen\n1. [Law name] - [URL]\n2. [Law name] - [URL]",
  "tools": [
    "semantische_rechtssuche_mcp_rechtsinformationen",
    "deutsche_gesetze_suchen_mcp_rechtsinformationen",
    "rechtsprechung_suchen_mcp_rechtsinformationen"
  ]
}

Key Settings:

• recursionLimit: 5 - Prevents endless searching (typical issue with some models)
• temperature: 0.3 - Accuracy over creativity for legal research
• STOP instructions - Forces agent to synthesize answer after finding results
• Citation requirements - Mandatory URL inclusion in responses

See LIBRECHAT_AGENT_CONFIG.md for complete configuration details.

🧪 Testing & Evaluation

Run Tests

# Run golden test cases
npm test

# Test API connectivity
npm run test:api

# Verify complete setup
npm run verify

Agentic Evaluation

To evaluate agent performance with different models:

# Analyze LibreChat conversation exports
node tests/eval-simple.js tests/your-conversation.json

Metrics tracked:

• Tool call efficiency (target: ≤3 calls)
• Document accuracy (found correct ECLI/ELI)
• Citation completeness (URLs in sources)
• Recursion safety (no limit hits)
• Answer quality (comprehensive + cited)

See AGENTIC_EVAL_GUIDE.md for detailed evaluation framework.

🔧 Troubleshooting

Common Issues

1. No Search Results

# Test API connectivity
npm run test:api

# Check if you have internet connection
curl https://testphase.rechtsinformationen.bund.de/v1/legislation

2. Server Won't Start

# Check Node.js version (needs v18+)
node --version

# Rebuild
npm install && npm run build

3. Recursion Limit Hit

Symptom: Agent makes 10+ tool calls without stopping

Solution:

• Set recursionLimit: 5 in agent config
• Add explicit STOP instructions
• Use semantische_rechtssuche as primary tool

4. Missing Citations in Output

Symptom: Agent doesn't include URLs despite MCP response containing them

Solution:

• This is a model behavior issue, not server issue
• Strengthen instructions: "MUST include ALL URLs"
• Consider agentic architecture with dedicated citation agent

5. Schema Validation Errors

Symptom: "Received tool input did not match expected schema"

Solution: ✅ Fixed - server now handles string→number type coercion

📖 Usage Examples

Simple Query

User: "Wie lange kann ich in Elternzeit gehen?"

Agent: Uses semantische_rechtssuche("Elternzeit Dauer")
→ Finds BEEG § 15
→ Answer: Up to 3 years per child

Sources:
1. https://testphase.rechtsinformationen.bund.de/.../regelungstext-1.html

Compound Word Query

User: "Was passiert bei einem Mieterhöhungsantrag?"

Agent: Uses semantische_rechtssuche("Mieterhöhungsantrag")
→ Decomposes to "Mieterhöhung"
→ Finds § 558 BGB
→ Answer: Rent increase procedures

Sources:
1. https://testphase.rechtsinformationen.bund.de/.../regelungstext-1.html

English Query

User: "What are employee rights during company restructuring?"

Agent: Uses semantische_rechtssuche(translates to "Arbeitnehmerrechte Betriebsumstrukturierung")
→ Finds KSchG, BetrVG
→ Answer: Dismissal protection and works council participation

Sources:
1. https://testphase.rechtsinformationen.bund.de/.../regelungstext-1.html

🏗️ Architecture

How It Works

User Query
    ↓
AI Agent (Claude/Qwen/etc)
    ↓
MCP Server (this project)
    ↓
rechtsinformationen.bund.de API
    ↓
German Federal Legal Database

Communication: Local stdio (no HTTP ports) Data Flow: Real-time API calls for each query URLs: Returns both HTML (users) and JSON (developers)

Intelligent Search Features

1. English Translation

"employee rights" → "Arbeitnehmerrechte"
"data protection" → "Datenschutz"
"dismissal" → "Kündigung"

2. Misconception Correction

"Überprüfungsantrag" → ["Widerspruch", "Rücknahme", "Widerruf"]
"§ 535 BGB Mieterhöhung" → "§ 558 BGB" (correct law)

3. Compound Word Decomposition

"Mieterhöhungsantrag" → "Mieterhöhung" (309 results)
"Kündigungsschutzantrag" → "Kündigungsschutz"
"Sozialhilfeantrag" → "Sozialhilfe"

4. Legal Reference Extraction

Detects: § 44 SGB X, Art. 3 GG, § 558 Abs. 2 BGB
Validates: Law abbreviations (BEEG, BGB, SGB, etc.)

📊 API Source

Base URL: https://testphase.rechtsinformationen.bund.de/v1 Documentation: https://docs.rechtsinformationen.bund.de Standards: ELI (European Legislation Identifier), ECLI (European Case Law Identifier) Status: Trial service - may be subject to changes

Coverage:

• ✅ Current federal legislation
• ✅ Federal court decisions (2010-2024)
• ✅ Historical versions of laws
• ⚠️ Amendment laws (partial coverage)
• ❌ Legislative materials (not included)

⚠️ Known Limitations

1. Date Filtering Issues

Problem: Temporal filters may exclude relevant results when laws enacted in one year become effective in another.

Example: Searching for "§ 44 SGB X Änderung 2021" with date filter 2021 misses the 7. SGB-IV-Änderungsgesetz from June 2020 (effective January 1, 2021).

Workaround: Search without date filters, manually review effective dates.

2. Amendment Law Discovery

Problem: Amendment laws are poorly indexed and may not show which paragraphs they modify.

Workaround:

• Search for "BGBl [year]" to find Federal Law Gazette entries
• Look for "Artikelgesetz" or amendment law names
• Search effective dates like "2021-01-01 Inkrafttreten"

3. Historical Versions

Problem: Only current versions easily accessible through ELI identifiers.

Workaround: Search Federal Law Gazette references for specific dates.

4. Model Behavior

Citations not appearing: Some models ignore citation instructions despite clear guidance in MCP response. This is a model limitation, not server issue.

Solution: Use agent configuration with explicit citation requirements or consider multi-agent architecture.

🚀 Recent Fixes (2025-10-06)

Major Improvements

✅ HTML URLs for Users

• Returns clickable HTML links instead of JSON API URLs
• Users can now read laws in browsers
• Both HTML and JSON URLs provided

✅ German Compound Word Handling

• Decomposes "Mieterhöhungsantrag" → "Mieterhöhung"
• Removes suffixes: -antrag, -verfahren, -klage, -gesetz, -verordnung
• Special handling for common legal terms

✅ Fallback Search

• Never returns zero results for valid queries
• Searches with original query if no legal references found
• Provides helpful suggestions when nothing found

✅ Type Coercion

• Handles models passing "10" (string) instead of 10 (number)
• Schema validation now works with GLM-4.6 and similar models

✅ Model-Agnostic Instructions

• Removed Claude-specific language
• Works with any AI model
• Clear imperative instructions

📝 Development

Build Commands

npm run build       # Compile TypeScript
npm run dev         # Development mode with tsx
npm start           # Run production build
npm test            # Run test suite

Helper Commands

npm run claude-config  # Generate config for Claude Desktop
npm run check-config   # Show config file path
npm run verify         # Complete verification
npm run setup          # Install + build + test

Project Structure

src/
├── index.ts                 # Main MCP server
tests/
├── golden_case_tests.json   # Test cases
├── test-golden.js           # Test runner
├── eval-simple.js           # Agent evaluation
debug/
├── test-*.js                # API debugging tools

🤝 Contributing

Contributions welcome! Areas for improvement:

1. More compound word patterns - Expand German word decomposition
2. Better concept mappings - Add common legal misconceptions
3. English translation coverage - More legal term translations
4. Historical version access - Better handling of law amendments
5. Literature search - Add /v1/literature endpoint support

📄 License

MIT

🔗 Related Documentation

• CLAUDE.md - Detailed instructions for Claude Code
• AGENTIC_EVAL_GUIDE.md - Agent evaluation framework
• LIBRECHAT_AGENT_CONFIG.md - LibreChat configuration
• RECOMMENDED_MODELS.md - Model comparison and recommendations
• FIXES_APPLIED.md - Detailed change log

---

Last Updated: 2025-10-06 Version: 1.1.0 Status: Production-ready with test phase API