What OpenAI's Astra for Law means for you

OpenAI has built a specialised version of its most powerful model, GPT-6 Astra, aimed at lawyers and law firms. It's called Astra for Law, and it's designed to search legal documents, draft with proper citations, and plug into the software firms already use.

OpenAI announced Astra for Law on 17 September 2026. It shows up as "GPT-6 Astra Law" inside ChatGPT's model picker, and pairs the underlying GPT-6 Astra model with settings and tools built for legal work, according to OpenAI.

The centrepiece is a Legal Search Index covering more than 230 million web addresses of US case law, statutes, regulations, court rules and administrative decisions, refreshed daily. Case law comes through a partnership with the nonprofit Free Law Project, whose CourtListener database gives the model access to more than 99.9% of published US precedential case law.

The tool connects to 26 partner plugins from legal software vendors including Thomson Reuters, Intapp, Relativity, Clio and DeepJudge, plus nine community-built plugins offering 47 separate skills. A companion tool, ChatGPT for Word, is now generally available.

On privacy, eligible firms get "zero data retention" — meaning their queries and documents aren't stored — and are excluded from human review of their data by default.

OpenAI tested the tool on 200 US legal research questions from the Vals Legal Research Bench, a benchmark for measuring legal research accuracy. Astra for Law scored 54.0% correct, against 38.7% for the standard GPT-6 Astra using web search, and found 24% more relevant cases when answering case-law questions. OpenAI has not published an independent comparison against established legal research platforms such as Westlaw or Lexis.

One early example: at law firm Ropes & Gray, a due-diligence system built on the tool traces its findings back to source documents and checks whether a company's contracts require notice or consent before an acquisition can go ahead, according to Artificial Lawyer.

If you're not a lawyer, this tool isn't for you directly, and the notes don't suggest a consumer version is coming. If you work at a law firm, it could speed up legal research and due diligence, but OpenAI's own accuracy figure, 54%, shows it still gets a substantial share of research questions wrong, so its outputs would need checking rather than being taken as final answers.

Access is currently limited to selected US law firms through OpenAI's Trusted Access and Codex programmes. Early adopters named by OpenAI include Latham & Watkins, Ropes & Gray, Cooley and Sullivan & Cromwell. Legal software companies Harvey and Legora are also building Astra for Law into their own products. An API for wider developer access is described as "coming soon", with no date given.