Anthropic announced Claude Fable 5.2 and Claude Mythos 5.2 today. The company says the models are built for “daunting” technical challenges. It claims both improve on coding, reasoning and vision, while producing outputs faster than their 5.1 versions.
Anthropic says Claude Fable 5.2 can handle difficult software engineering problems. It can also coordinate teams of agents and work on projects that run for extended periods, according to the company.
The models solved complex problems in testing
The company points to scientific work as another example of the models’ capabilities. During prerelease testing, Anthropic says the two models “helped our engineers complete otherwise-infeasible software migrations, designed three working electronic devices from scratch, solved two open problems in the physics of black holes, made substantial progress on robotics evaluations, and formalized the proof of Fermat’s Last Theorem in 30 hours.”
That account spans software, electronics, theoretical physics and robotics. The results Anthropic describes came from prerelease testing, rather than a broader public release of both models.
Anthropic is restricting access to Mythos 5.2
The new models follow Claude Fable 5.1 and Claude Mythos 5.1, which Anthropic released in September. Claude Fable 5.2 launches today. Access to Claude Mythos 5.2 will initially be limited to vetted organizations.
