A first real answer before you have an account.

Start with /v1/law/coverage. It takes no key, bills nothing, and answers the question every other call depends on — is this jurisdiction and this body of law in the corpus at all, and how far back does it go. Narrow it with jurisdiction and corpus, or omit both for everything.

curl "https://api.binding.law/v1/law/coverage?jurisdiction=fl&corpus=statutes"

{
  "coverage": [
    {
      "jurisdiction": "fl",
      "corpus": "statutes",
      "name": "Florida",
      "cadenceClass": "edition",
      "temporalBasis": "compiled-edition",
      "coverageFrom": "2010-07-01",
      "latestVersion": "2025",
      "sections": 26776,
      "versions": 48076,
      "lastRetrievedAt": "2026-07-22 05:14:30.429+00"
    }
  ],
  "note": "asOf dates earlier than coverageFrom return no_edition_on_file; a jurisdiction+corpus absent from this list returns not_carried. temporalBasis declares what validity bounds mean per jurisdiction.",
  "generatedAt": "2026-09-20T19:51:41.148Z"
}

Two fields decide how you read everything else. coverageFrom is the floor for point-in-time queries. temporalBasis says what the validity dates mean for that jurisdiction — compiled-edition resolves to the edition in force (a March 2020 date lands on Florida’s 2019 edition, not 2020), act-effective-date to the date the text actually took effect, and as-observed to the day we first observed that text at the source.

Everything past coverage and quality needs Authorization: Bearer. Sign up for a key, then resolve a citation as of a date. The response carries the section text, its validity window, and the provenance you would need to defend the quote.

curl "https://api.binding.law/v1/law/lookup?jurisdiction=fl&citation=768.28&asOf=2019-03-01" \
  -H "Authorization: Bearer lf_live_..."

A successful lookup returns one section version wrapped in result. Inside it, provenance names the exact page the text was read from (sourceUrl), when it was read (retrievedAt), the SHA-256 of the normalized body (contentHash), the publishing system (sourceSystem) and the edition label (versionLabel). Alongside it, validFrom and validTo bound the period this text was in force, and permalink is a binding.law URL a human can open.

Provenance is on every tier and every response, including the free one. If a field cannot be sourced it is not served. Search results carry the same provenance object per hit; the compact /v1/law/text variant carries versionLabel and permalink instead of the full object, so an agent quoting a section still has somewhere to send the person who asks where it came from.

binding.law never resolves a citation to the nearest thing it has. A lookup that finds nothing returns 404 with one of two codes, and the difference between them is the single most important thing to get right in an integration.

The errors page has the full list, the verbatim messages, and the reason this distinction exists.

/v1/statutes/* is a permanent alias for /v1/law/* — same handlers, same responses. It exists because earlier integrations hardcoded it. New code should use /v1/law/*.

The API is designed to be called from a server. It does not send permissive CORS headers, so a browser cannot call it directly from an arbitrary origin; proxy it through your own backend.