Anthropic releases Claude Fable 5.2 and Mythos 5.2

Anthropic describes Fable 5.2 as suited to difficult software engineering work, including coordinating teams of agents and managing long-running projects. The company also says the model has solved complex scientific problems, among them two open theoretical physics problems.

In prerelease testing, Anthropic says the two models helped engineers complete software migrations it called otherwise infeasible, designed three working electronic devices from scratch and made substantial progress on robotics evaluations. The company also said they solved two open problems in black-hole physics and formalized a proof of Fermat’s Last Theorem in 30 hours.

Fable 5.2 launches today. Mythos 5.2 will initially be available only to vetted organizations. The releases follow Claude Fable 5.1 and Claude Mythos 5.1, which launched in September.