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 (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