Implausible Enterprises Legal Research

LLM Law Library

Free, open legal research for humans and AI.

10.7M opinions 1.9M statutes 876K definitions 52 jurisdictions 1685–present

Search 10.7 million court opinions across all 50 states and federal courts. Use BM25 mode for exact citations and party names.
Search 1.9 million statutory sections across all 50 states, DC, and federal law. Filter by jurisdiction to search a single state.
Look up where any legal term is statutorily defined across US jurisdictions. 876K definition pointers, 210K unique terms. Enable “red flags” to see where a term is used but NOT defined.
10.7M

Case Law

Every published US court opinion, 1685 to present. All 50 states + federal. Hybrid search (BM25 + semantic vector). Shepardizer v2: 3.7M treatments.

1.9M

Statutes

All 50 states + DC + federal (US Code). 52 jurisdictions. BM25 deterministic search. Filterable by state.

876K

Definitions

Where each legal term is statutorily defined. 210K unique terms, ranked by how often courts cite each definition.

6,600+

Red Flags

Terms used in statutes but NOT defined in that jurisdiction. The dangerous gap: a definition you don’t know exists.

Install the MCP (Claude Code)

One command. No dependencies beyond Python 3.

curl -O https://raw.githubusercontent.com/giblfiz/llm-law-lib/master/caselaw-mcp.py claude mcp add llm-law-library python3 $(pwd)/caselaw-mcp.py

Install the MCP (Claude Desktop)

Download caselaw-mcp.py, then add to config:

{ "mcpServers": { "llm-law-library": { "command": "python3", "args": ["/path/to/caselaw-mcp.py"] } } }

REST API

No authentication required. JSON in, JSON out.

# Search case law curl -X POST https://implausible.enterprises/api/caselaw/search \ -H 'Content-Type: application/json' \ -d '{"query":"qualified immunity","mode":"hybrid","top_k":5}' # Search statutes (California only) curl -X POST https://implausible.enterprises/api/caselaw/statute/search \ -H 'Content-Type: application/json' \ -d '{"query":"negligence","jurisdiction":"state:CA"}' # Look up a term definition curl -X POST https://implausible.enterprises/api/caselaw/term/search \ -H 'Content-Type: application/json' \ -d '{"term":"fiduciary","include_red_flags":true}'

Key Concepts

Search modes
Hybrid (default) fuses BM25 + vector via RRF. BM25 is deterministic. Vector finds conceptually similar passages.
Shepardizer
Tracks how later courts treated each case. Severity: overruled > abrogated > reversed > vacated > superseded > questioned > distinguished > limited > criticized > modified.
Red flags
Terms used heavily but with no statutory definition found. Four causes: cross-reference gap, missed cross-reference, common-law reliance, or extraction gap.
Definition pointers
We store WHERE terms are defined, not the definitions themselves. “Person” has 40+ definitions across jurisdictions.
Trust hierarchy
xml_structured > caselaw_cite > bm25_pattern > flash_classification
Data
Caselaw from CourtListener / Free Law Project (CC0). Federal statutes from OLRC USLM XML. State statutes from official legislative websites. Not legal advice.

Loading corpus status…