Search and retrieve US court opinions, federal dockets, judge records, citation networks, and oral arguments from CourtListener's 9M+ opinion corpus via MCP. STDIO or Streamable HTTP.
claude mcp add --transport http courtlistener-mcp-server https://courtlistener.caseyjhand.com/mcpcodex mcp add courtlistener-mcp-server --url https://courtlistener.caseyjhand.com/mcp{
"mcpServers": {
"courtlistener-mcp-server": {
"url": "https://courtlistener.caseyjhand.com/mcp"
}
}
}gemini mcp add --transport http courtlistener-mcp-server https://courtlistener.caseyjhand.com/mcp{
"mcpServers": {
"courtlistener-mcp-server": {
"command": "bunx",
"args": [
"@cyanheads/courtlistener-mcp-server@latest"
]
}
}
}{
"mcpServers": {
"courtlistener-mcp-server": {
"type": "http",
"url": "https://courtlistener.caseyjhand.com/mcp"
}
}
}curl -X POST https://courtlistener.caseyjhand.com/mcp \
-H "Content-Type: application/json" \
-H "MCP-Protocol-Version: 2025-11-25" \
-d '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"protocolVersion":"2025-11-25","capabilities":{},"clientInfo":{"name":"curl","version":"1.0.0"}}}'Full-text search across 9M+ written US court opinions with field-level filtering. Returns opinion cluster summaries with case metadata, citations, and matched text snippets. Supports CourtListener field syntax (caseName:"roe v wade", court_id:scotus, judge:"Alito") and boolean operators (AND, OR, NOT). Use courtlistener_lookup_courts to find court IDs. Rate limit: 5 req/min, 50/hr, 125/day on the free tier.
Fetch the full text and metadata for a single opinion cluster by cluster ID. A cluster groups all opinions filed in a case — majority, concurrence, dissent, and per curiam. Returns all opinion variants with HTML and plain text. Obtain cluster IDs from courtlistener_search_opinions, courtlistener_lookup_citation, or docket results.
Retrieve the citation network for an opinion cluster. Supports two directions: "cited_by" (opinions that cite this one — measures precedential influence) and "citing" (opinions this one cites — reveals the authority chain relied on). This is the primary tool for tracing legal precedent chains. Note: the free tier (125 req/day) supports shallow traversal — following 1–2 hops of a single case is practical; deep multi-hop analysis burns through the daily budget quickly.
Resolve a formatted legal citation string (e.g., "410 U.S. 113", "93 S. Ct. 705") to a cluster ID and case metadata. Enables workflows that start from a known citation rather than a search query. Supports standard US reporter formats. Requires authentication — uses the CourtListener /citation-lookup/ endpoint.
Search RECAP federal court dockets with party name, attorney, court, and date filters. RECAP is a crowd-sourced mirror of PACER (the federal court filing system) — coverage varies by court and date. Returns docket metadata with up to 3 sample document entries per docket. Use courtlistener_lookup_courts to find court IDs.
Fetch full docket metadata and entry list for a single federal case by docket ID. Returns all available docket entries with document availability status. Documents with is_available=true have a RECAP-stored copy; others require a PACER account. Obtain docket IDs from courtlistener_search_dockets or from opinion results.
Search judge/person records by name, appointing president, court, political affiliation, or demographic. Returns biographical data, current position, and appointment summary. Use courtlistener_get_judge for full appointment history and education records.
Fetch full biographical profile for a single judge: appointment history across all courts, education, political affiliations, and ABA ratings. Obtain person IDs from courtlistener_search_judges results.
List courts with optional filtering by jurisdiction type and scraper status. Primarily used to discover court IDs for use in search and filter parameters across all other courtlistener tools. Returns court IDs, full names, citation strings, and scraper status.
Search appellate oral argument audio recordings — the largest public collection of oral argument audio. Returns recording metadata with download URLs, panel judge IDs, and transcript snippets where available. Download URLs are direct MP3 links. Panel judge IDs can be passed to courtlistener_get_judge for biographical context.
No tools match the current filter.
Static reference guide for CourtListener court IDs, jurisdiction type codes, search type codes, and rate limit information. Read this before building queries to find the correct court ID and jurisdiction filter values.
Generate a structured legal research plan for a given legal topic or question. Produces a step-by-step workflow using CourtListener tools to find relevant case law, trace precedent chains, and surface key opinions.
topicrequired
— Legal topic, question, or issue to research (e.g., "Fourth Amendment cell phone search", "Title VII hostile work environment", "Section 1983 qualified immunity").
jurisdiction
— Optional jurisdiction to focus on (e.g., "scotus" for Supreme Court, "ca9" for Ninth Circuit, "nyed" for SDNY). Omit for nationwide research.
depth
— "overview" (default): find 3–5 key cases. "deep": include citation network traversal and judge lookup. Note: deep research uses more of the 125 req/day free-tier budget.