Thomson Reuters Westlaw API
Real REST APIs live on the Thomson Reuters Developer Portal: Westlaw dockets, legislation, litigation analytics, KeyCite, and Practical Law. Auth is OAuth 2.0. Access requires a Westlaw subscription plus a separately negotiated API contract; there is no self-serve tier and no SDK.
Frequently asked questions
Thomson Reuters Westlaw scores D on the API Report Card. Real REST APIs live on the Thomson Reuters Developer Portal: Westlaw dockets, legislation, litigation analytics, KeyCite, and Practical Law. Auth is OAuth 2.0. Access requires a Westlaw subscription plus a separately negotiated API contract; there is no self-serve tier and no SDK.
Without a usable official API, teams fall back on manual exports, file drops, or one-off vendor integrations. The other option is an unofficial API layer like Supergood that automates the authenticated web app directly.
Thomson Reuters Westlaw is the flagship online legal research platform of Thomson Reuters (NYSE: TRI, TSX: TRI), with roots in West Publishing (founded 1872 in St. Paul, Minnesota by John B. West) and the original Westlaw service launched in 1975.
Primary vertical: Legal. Closest Supergood sub-vertical: Legal Research / Tax Research, Westlaw is the canonical example of this category alongside LexisNexis and Bloomberg Law. A litigation associate at an Am Law 100 firm runs Westlaw all day: searches for binding precedent on a motion to dismiss, runs KeyCite on every cited case to verify it hasn't been overruled or distinguished, pulls headnotes and the Key Number digest to expand the research path, reviews briefs and motions filed in analogous cases via Litigation Analytics, drafts a memo with CoCounsel Legal summarizing the resulting authorities, and exports the result into Microsoft Word with proper Bluebook citations.
Very high within the US legal market.
Westlaw API calls sit on the critical path of legal work product where errors translate directly into malpractice exposure, missed deadlines, and bad citations in filings.
Westlaw is one of the oldest commercial online research platforms in any industry, launched in 1975, predating the consumer internet.
Grades measure one thing: can a customer's engineering team get their own data out programmatically? We check six things (whether a real API exists, how access is gated, data coverage, auth quality, docs and developer experience, and stability) and roll them into a letter grade. Grades get re-verified, and they only move on evidence.