A configuration, not a new model
Astra for Law combines GPT-6 Astra with a legal search index, instructions for legal analysis and writing, and settings and tools for professional legal work. It will appear in ChatGPT's model picker as GPT-6 Astra Law and in the API as gpt-6-astra-law. The index covers U.S. case law, statutes, regulations, court rules and administrative decisions across more than 230 million URLs, and includes the case-law collection of Free Law Project's CourtListener, which OpenAI says covers more than 99.9 percent of published U.S. precedential case law. [1][2]
It was offered first to selected law firms through Trusted Access in ChatGPT and Codex, with API access to follow, at which point API customers including Harvey and Legora will be able to build on it. OpenAI also released 26 ecosystem plugins connecting ChatGPT to legal tools such as Relativity and Clio. The announcement gives no price. [1]
OpenAI's measurement
OpenAI tested the full setup on 200 U.S. legal research questions from the private validation set of Vals AI's Legal Research Bench. At the highest reasoning effort, Astra for Law passed the overall correctness check on 54.0 percent of questions against 38.7 percent for GPT-6 Astra using web search alone. OpenAI also reports that it found 24 percent more reference cases on case-law questions and up to 54 percent more relevant passages from the correct opinions. [1]
Atlas interpretation: These are OpenAI's runs on a private question set, comparing the full configuration with the same model using web search, so they show what the configuration adds rather than how Astra for Law compares with other legal products. OpenAI names Thomson Reuters, Harvey, Legora and iManage among the partners whose plugins connect their tools to ChatGPT, so legal software companies that could compete with it are also building on it. [1][3]
Sources
- Introducing Astra for Law
OpenAI · Sep 17, 2026
- Breaking news: OpenAI unveils Astra for Law
Legal IT Insider · Sep 17, 2026
- OpenAI Launches Astra For Law
Artificial Lawyer · Sep 18, 2026