On September 17, 2026, OpenAI introduced Astra for Law: GPT-6 Astra configured with settings, tools, and context for professional legal work — a foundation for law firms and legal tech companies. Not a new base model: GPT-6 Astra + legal search index + instructions for legal analysis and writing. Legal search index: U.S. case law, statutes, regulations, court rules, administrative decisions; corpus of more than 230 million URLs, sources added daily; complements licensed content from providers such as Thomson Reuters; Free Law Project / CourtListener case-law collection covering more than 99.9% of published U.S. precedential case law (OpenAI claim citing Free Law Project). Benchmark (OpenAI-reported, not ElevateU-verified): Vals AI Legal Research Bench private validation set, 200 U.S. legal research questions; at highest reasoning effort Astra for Law 54.0% overall correctness vs GPT-6 Astra + web search alone 38.7% (~40% relative improvement per OpenAI); case-law questions 24% more reference cases; audited target passages up to 54% more relevant passages from correct opinions at same reasoning effort. Availability: initially selected law firms via Trusted Access in ChatGPT and Codex; coming soon to API; model picker “GPT-6 Astra Law”; API gpt-6-astra-law; API customers including Harvey and Legora will be able to build on it. Trusted Access for eligible firms: Zero Data Retention (ZDR) on API; ChatGPT Enterprise usage excluded from human review by default; working with Latham & Watkins on info permissions, ethical walls, client instructions, firm oversight. Firm builds named: Sullivan & Cromwell agreement analyzer; Ropes & Gray deal diligence; Cooley GO Public (IPO filing). 26 partner-built plugins (examples Relativity, Clio, iManage, Intapp, DeepJudge; Thomson Reuters HighQ matter context + preview CoCounsel Legal connector). 9 community plugins (LegalQuants, LECG, Skills.law) with 47 custom skills. ChatGPT for Word generally available same day (proofread, suggested edits, formatting in Word). Short attributed quotes OK: Niko Grupen (Harvey); John Savva (Sullivan & Cromwell). Do not re-ship GPT-6 Astra base (Sep 3). Primary verified via signal/sources/EU-SIGNAL-20260918-001/evidence-openai-astra-for-law.md.
OpenAI is shipping a professional-services configuration pack — legal index + instructions + Trusted Access + plugins — on top of GPT-6 Astra, not a fresh base-model drop. Track as firm/legal-tech packaging, governance controls, and ecosystem connectors for AI for Work. Attribute Vals AI Bench figures and Free Law Project coverage as OpenAI-reported; do not re-ship the Sep 3 GPT-6 Astra base launch as this Signal.
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Sep 17, 2026: Astra for Law = GPT-6 Astra configuration + legal search index + legal analysis/writing instructions (not a new base model).
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Index: U.S. case law/statutes/regulations/court rules/admin decisions; >230M URLs; Free Law Project / CourtListener (OpenAI: >99.9% published U.S. precedential case law); complements Thomson Reuters–style licensed content.
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FLAG — eval: Vals AI Legal Research Bench private set (200 Qs): 54.0% vs 38.7% web-search baseline (~40% relative); 24% more reference cases; up to 54% more relevant passages — OpenAI-reported, not ElevateU-verified.
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Availability: Trusted Access (selected firms) in ChatGPT/Codex; API coming soon; picker GPT-6 Astra Law / API gpt-6-astra-law; Harvey & Legora named as API builders.
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Trust: ZDR on API; Enterprise excluded from human review by default; Latham & Watkins governance collaboration.
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Ecosystem: Firm builds (S&C, Ropes & Gray, Cooley GO Public); 26 partner plugins + 9 community plugins / 47 skills; ChatGPT for Word GA same day.
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RULE: Do not re-ship GPT-6 Astra base (Sep 3) as this story.
Last verified: 2026-09-18T13:40:00Z · Speaker predictions remain attributed to the speaker. ElevateU analysis is labeled separately from source-supported fact.