OpenAI Launches Astra for Law Built on GPT-6 Astra

On September 17, 2026, OpenAI announced OpenAI's announcement of Astra for Law: Astra for Law, a new AI foundation designed for law firms and legal technology companies. The system combines GPT-6 Astra with a legal search index and custom instructions tailored for legal analysis and writing.

The legal search index covers U.S. case law, statutes, regulations, court rules, and administrative decisions across a corpus of more than 230 million URLs, with sources added daily. Through a partnership with the Free Law Project, the case-law collection covers more than 99.9% of published U.S. precedential case law.

OpenAI tested Astra for Law 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% of questions, compared with 38.7% for GPT-6 Astra using web search alone, marking a 40% relative improvement. It also found 24% more reference cases and retrieved up to 54% more relevant passages from correct court opinions.

API customers such as Harvey and Legora will build on the new foundation. Firms can also customize Astra for Law using 26 new ecosystem plugins that connect ChatGPT to tools like Relativity and Clio.

Astra for Law will initially be offered to selected law firms through Trusted Access in ChatGPT and Codex, and will arrive soon in the API under the name gpt-6-astra-law and in the model picker as “GPT-6 Astra Law”.