Introducing Astra for Law

Astra for Law combines GPT‑6 Astra with a powerful legal search index and instructions for legal analysis and writing. Together, they amplify Astra’s capabilities across the legal practice, while giving firms and legal technology companies the freedom to build their own applications and workflows.

Our new legal search index is one of the tools Astra for Law can use. Legal research often begins with finding the exact right authority, locating the relevant passages, and understanding how relevant and binding they are to the situation at hand. The index helps Astra for Law do that work, and complements the licensed content and specialist products firms rely on from providers such as Thomson Reuters.

By using the legal search index, Astra for Law can search U.S. case law, statutes, regulations, court rules, and administrative decisions across a corpus of more than 230 million URLs, with sources added daily. Our work with Free Law Project, the nonprofit behind CourtListener, brings its case-law collection covering more than 99.9% of published U.S. precedential case law⁠(opens in a new window) into this research experience.

To measure how this configuration improves legal research, we tested Astra for Law’s complete setup on 200 U.S. legal research questions from the private validation set of Vals AI’s Legal Research Bench⁠(opens in a new window). This benchmark measures how well the model can find relevant sources and passages, and how well its research answers meet the evaluation criteria.

At the highest reasoning effort for both systems, Astra for Law passed the evaluation’s overall correctness check on 54.0% of questions, compared with 38.7% for GPT‑6 Astra using web search alone – a 40% relative improvement. Astra for Law also produces more comprehensive answers.

On case-law-focused questions, Astra for Law found 24% more reference cases than GPT‑6 Astra using web search alone at the highest reasoning effort. On the audited set of target passages, it retrieved up to 54% more relevant passages from the correct court opinions, when comparing the systems at the same reasoning effort.

The result is a stronger research foundation for advising on a deal, assessing a dispute, or developing a legal strategy, with reliable authorities the lawyer can examine for herself.

Legal research is only the first step. Custom instructions for legal analysis and writing guide Astra for Law in applying that research to the client’s facts, developing arguments or deal terms, and identifying weaknesses and uncertainty. That can mean distinguishing a court’s holding from its other observations, addressing cases that weaken an argument, or explaining how a contract exception shifts risk between the parties.

For example, when prompted to identify good law with similar fact patterns, Astra for Law could both pinpoint relevant precedent and match fact patterns better than other frontier models:

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

Law firms need to protect client confidences and control how AI is used in their practice. We’ve created a special Trusted Access Program for eligible law firms to give lawyers and people working under their supervision access to Astra for Law for professional legal work. For eligible firms, the offering includes Zero Data Retention (ZDR) on our API, and usage of ChatGPT Enterprise is excluded from human review by default.

We are also working with Latham & Watkins, a leader in AI governance, to design for information permissions, ethical walls, client instructions, and firm oversight.

With frontier intelligence and the right controls, firms can turn their own precedents, methods, and judgment into AI tools and workflows built to their standards.

Working with selected firms, our forward-deployed engineers have been adapting ChatGPT Enterprise with custom interfaces and integrations to proprietary data, creating tools for each firm’s workflows:

Firms can build with their own teams and partner products, with permitted sources and review processes defined for the work.

We’re proud to work with the specialist companies who are advancing legal AI. Today, we’re launching 26 partner-built plugins⁠ that help firms go deeper with the tools and knowledge they already use. These plugins cover the practice and business of law. With iManage, a lawyer can draft a negotiation brief in ChatGPT and save it to the matter file; Intapp can surface activities that may need a time entry for review; DeepJudge can bring prior deals into a comparison. Thomson Reuters is bringing HighQ matter context into ChatGPT and previewing a forthcoming CoCounsel Legal connector.

The launch includes 9 community plugins from lawyers and legal engineers at LegalQuants, LECG, and Skills.law, with 47 custom skills that practitioners can adapt, extend, or draw inspiration from to do their work in ChatGPT. Community plugins give the people closest to the work a way to keep setting the standard for what these skills can do. We’re also making ChatGPT for Word generally available today, so lawyers can proofread, get suggested edits, and flag formatting issues in the tool they already rely on for drafting.

Our approach is open and composable: firms can use specialist products, bring their own tools and knowledge, and adapt community-built skills to their practice. Partners can keep developing their own applications and workflows, while firms choose how those capabilities fit together. Building on OpenAI should mean getting more from the ecosystem, not replacing it.

OpenAI is investing in law for the long term. We’ll keep advancing Astra for Law’s model, settings, tools, and instructions together, guided by rigorous evaluations and feedback from lawyers and legal technology partners. We’ll also keep improving ChatGPT so firms can build around their expertise and connect the tools they use.

Our work with Wachtell, Lipton, Rosen & Katz brings the firm’s litigation and corporate expertise together with our frontier research and engineering to explore how AI can support the work involved in providing sophisticated legal judgment.

The most ambitious applications will come from the people who practice law and the companies building alongside them. We’re committed to working with this ecosystem so firms can bring their own expertise, standards, and judgment to AI—and serve clients in ways only they can.

To explore early access to Astra for Law, build it into your product, or develop tools around your firm’s expertise, contact OpenAI.