LitLex API

The research corpus, over an API.

The API serves the same corpus and citator that power Litco’s reader. Your software can search the corpus, pull opinions and statutes, check a case’s treatment, and verify quotations. Litco returns every result straight from the corpus records and never routes requests through a model.

Give an API key to Claude Code, OpenClaw, a Hermes deployment, or an application your team wrote. Instead of reciting law from memory, your agent looks the law up—full-text opinions with paragraph anchors, citator treatment, statutes and regulations with currency dates. A verification endpoint lets your agent check whether a quotation is real before repeating that quotation in a draft. The corpus behind the key covers the Supreme Court and every federal circuit, and Litco refreshes the data on a rolling basis. An agent built on this API reads the same law a paid research platform shows.

Litco supports Lobster, and firms running OpenClaw agents can connect them directly.

Verify quotations before the Matter Agent repeats them.

Lawyers send a quotation and a citation to a single endpoint. The endpoint checks whether the reporter text contains that quotation and returns the matching passage.

# request
POST /v1/cite-check
{ "quote": "must give effect to the unambiguously
            expressed intent of Congress",
  "opinion_id": "<uuid or short_id>",
  "paragraph_number": 24 }

# response (shape per the public spec)
{ "data": {
    "verdict": "verified_exact",
    "match": { "anchor": "<short_id>::p.24",
               "case_name": "...",
               "paragraph_number": 24,
               "reporter_pincite": "467 U.S. 837, 843" },
    "pinpoint_correct": true } }

Every result includes a citation anchor.

Search takes a doctrine or a fact pattern and returns paragraph-level hits. Each hit shows the anchor to cite, a snippet, and a treatment-status chip. Before quoting from an opinion, the Matter Agent can check that the cited case still stands.

# request
POST /v1/search
{ "query": "agency interpretation of an ambiguous
             statute entitled to deference",
  "filters": { "courts": ["scotus"] },
  "top_k": 3 }

# response (shape per the public spec)
{ "data": { "hits": [
    { "anchor": "<short_id>::p.11",
      "case_name": "Chevron U.S.A. Inc. v. NRDC",
      "opinion_type": "majority",
      "snippet": "...the question for the court is whether
                  the agency's answer is based on a
                  permissible construction of the statute.",
      "score": 0.93,
      "treatment_status": "negative" },
    { "anchor": "<short_id>::p.44",
      "case_name": "Loper Bright Enterprises v. Raimondo",
      "opinion_type": "majority",
      "snippet": "...courts need not and under the APA may
                  not defer to an agency interpretation of
                  the law simply because a statute is
                  ambiguous.",
      "score": 0.89,
      "treatment_status": "none" } ] },
  "meta": { "total_candidates": 214 } }

Every endpoint, plain HTTP.

A litigator sends a legal question to the Matter Agent and receives pinpoint citations with treatment history and verified quotations, delivered over plain HTTP.

POST  /v1/search                       Hybrid search (vector + FTS, RRF-fused) over all indexed federal opinions
GET   /v1/cite/resolve                 Resolve a case citation string into opinion id(s)
GET   /v1/opinions/{id}                Opinion text, paragraph-anchored
GET   /v1/opinions/{id}/citator        Is this case still good law? Treatment rollup + citing opinions
GET   /v1/opinions/{id}/authorities    Table of authorities: everything this opinion cites
GET   /v1/statutes/{cite}              USC/CFR text by citation, latest loaded version
GET   /v1/fr/search                    Federal Register search: rules, proposed rules, notices
POST  /v1/cite-check                   Verify one quote against corpus bytes

API keys are issued per firm and metered by request.

OpenAPI spec →