LexAPI

Model Context Protocol server for LexAPI — query EUR-Lex, EU case law, and the citation graph from Claude, Cursor, and other MCP-enabled clients.

Install once, get an API key, and ask your AI assistant: "summarize Article 17 of the GDPR" or "which regulations amend Directive 95/46/EC?" — the model calls LexAPI directly.

Install

You'll need a LexAPI API key. Create one for free at lex-api.com/dashboard (500 credits/month on the FREE tier, no card required).

Claude Desktop

Add to claude_desktop_config.json (location: ~/Library/Application Support/Claude/claude_desktop_config.json on macOS):

{
  "mcpServers": {
    "lexapi": {
      "command": "npx",
      "args": ["-y", "@lexapi/mcp"],
      "env": {
        "LEXAPI_API_KEY": "lex_..."
      }
    }
  }
}

Restart Claude Desktop.

Claude Code

claude mcp add lexapi --env LEXAPI_API_KEY=lex_... -- npx -y @lexapi/mcp

Cursor / other MCP clients

Any client that supports stdio MCP servers can run this. The command is npx -y @lexapi/mcp with LEXAPI_API_KEY in the environment.

Tools

Tool	What it does
lex_search	Structured EUR-Lex search (text, dates, document type, author, language).
lex_get_document	Full parsed document by CELEX — metadata + articles, sections, tables, annexes.
lex_get_metadata	Metadata only (faster than full content).
lex_get_document_by_url	Fetch by EUR-Lex URL (pasted from a browser).
lex_recent_documents	Recent Official Journal publications (default 7 days).
lex_cited_by	Documents citing this CELEX (inbound, typed edges).
lex_cites	Documents this CELEX cites (outbound, typed edges).
lex_citation_network	Both directions in one call.
lex_semantic_case_law	Embedding search over EU case law (paid plans).
lex_semantic_legislation	Embedding search over EU legislation (paid plans).

Configuration

Env var	Default	Purpose
LEXAPI_API_KEY	(required)	Your API key. Get one at lex-api.com/dashboard.
LEXAPI_BASE_URL	https://lex-api.com/api/v1	Override for self-hosted or staging.

Troubleshooting

LEXAPI_API_KEY is not set — the env var isn't reaching the spawned process. Double-check the env block in your MCP client config.

LexAPI error (401 invalid_api_key) — the key is wrong or revoked. Generate a new one at the dashboard.

LexAPI error (429 …) — you hit your daily quota or per-minute rate limit. The server retries once automatically; if you see this in tool output, you're over quota. Upgrade your plan or wait for reset.

LexAPI error (403 …) on semantic tools — semantic search requires a paid plan. FREE tier returns 403 for those endpoints.

Local development

git clone https://github.com/Lex-API/lexapi-mcp.git
cd lexapi-mcp
npm install
npm run build

LEXAPI_API_KEY=lex_xxx node dist/index.js

License

MIT