Anthropic launches new Claude Fable and Mythos 5.2 models

Anthropic has launched Claude Fable 5.2 and announced Claude Mythos 5.2, saying both models improve on their 5.1 versions in coding, reasoning and vision, while generating outputs faster. The release matters because Anthropic is positioning Fable for demanding software and scientific work, while limiting initial access to Mythos to vetted organisations.

Anthropic says Fable can coordinate teams of AI agents and handle long-running projects. In prerelease testing, the models reportedly helped with difficult software migrations, designed three working electronic devices, addressed two open problems in black-hole physics, advanced robotics evaluations and formalised a proof of Fermat’s Last Theorem in 30 hours. Fable 5.2 is available from today; the models’ 5.1 predecessors launched in September.