LexAPI MCP

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 (50 calls/day on the FREE tier).

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