OpenAI and Anthropic neared a mutual AI stress-test deal — coopetition meets antitrust optics

What's the deal? The Information reports that lawyers for OpenAI and AnthropicDealroom has a profile for this one. Try Dealroom → drafted a legally binding mutual stress-test earlier this year: each lab would red-team the other’s commercially available models via API (not unreleased systems), with guarantees neither would retain the other’s data. It is unclear whether the pact was signed before OpenAI’s wave of unreleased-model cybersecurity incidents.

Caveats: Person-familiar sourcing; no confirmation the agreement was signed, abandoned, or superseded by the third-party evaluator track; spokespeople no comment; limited Anthropic-side corroboration of the 2026 talks. How mutual testing sits next to Dario AmodeiDealroom has a profile for this one. Try Dealroom →’s antitrust concerns about labs collaborating on standards is unresolved in the piece.

The signal: Frontier labs almost wrote each other into their safety stack — a sticky coopetition / mutual-evaluation story with obvious antitrust and duopoly optics, not just another product race.

Source: The Information — OpenAI and Anthropic Neared Deal to Stress-Test Each Other’s AI (Amir Efrati, Stephanie Palazzolo).