# OpenAI launches Astra for Law with 230 million-document index

> OpenAI launched Astra for Law, a legal research AI, on 17 September.

*A legal version of GPT-6 Astra beats the base model on research accuracy in OpenAI's own benchmark.*

By Behzad Hosseini · FeaturedDaily
Canonical: https://featureddaily.com/news/openai-launches-astra-for-law-with-230-million-document-index

**What happened:** OpenAI launched Astra for Law on 17 September 2026, a version of its GPT-6 Astra model built for professional legal work. It shows up as "GPT-6 Astra Law" in the model picker.

**The numbers:** OpenAI's own test on 200 US legal research questions found 54.0% correctness, against 38.7% for standard GPT-6 Astra with web search. It also surfaced 24% more relevant cases on case-law questions. No independent comparison with existing legal research platforms exists yet.

**The details:** The tool runs on a Legal Search Index covering more than 230 million URLs of US case law, statutes, regulations, court rules and administrative decisions, updated daily. Case law comes via a partnership with nonprofit Free Law Project's CourtListener, covering over 99.9% of published US precedential case law. It also ships with 26 partner plugins from vendors including Thomson Reuters, Intapp, Relativity, Clio and DeepJudge, plus nine community plugins offering 47 skills. ChatGPT for Word is now generally available.

**The catch:** Access starts with selected US law firms via Trusted Access and Codex; an API is coming soon, not yet live.

**Who's affected:** Early adopters include Latham & Watkins, Ropes & Gray, Cooley and Sullivan & Cromwell. Legal AI platforms Harvey and Legora are building Astra for Law into their own products.

**Why it matters:** Eligible firms get zero data retention and default exclusion from human review, addressing a key confidentiality concern for legal work. Ropes & Gray has already built an M&A due-diligence system on it that traces findings to source documents and flags whether customer contracts need notice or consent for an acquisition.

**What's next:** Wider firm access and an API rollout follow the initial trusted-access phase, according to [OpenAI](https://openai.com/index/astra-for-law/). More detail on the launch is in [Artificial Lawyer's coverage](https://www.artificiallawyer.com/2026/09/18/openai-launches-astra-for-law/).

## Key takeaways

- Astra for Law scored 54% vs 38.7% on legal research benchmark
- Search index covers 230 million+ US legal documents, updated daily
- Early users include Latham & Watkins, Ropes & Gray, Cooley

## Sources

- [Introducing Astra for Law](https://openai.com/index/astra-for-law/) — OpenAI, 2026-09-17
- [OpenAI Launches Astra For Law](https://www.artificiallawyer.com/2026/09/18/openai-launches-astra-for-law/) — Artificial Lawyer, 2026-09-18