Claude Fable 5.2 and Mythos 5.2

Claude Fable 5.2 and Mythos 5.2 are Anthropic’s upgraded frontier models for the hardest technical work. They are the same underlying model: Fable is open to all users, while Mythos, without some of Fable’s cyber and biology safeguards, goes to vetted organizations. Per Anthropic, outputs are up to 30% faster than 5.1 at a lower price ($8 input, $40 output per million tokens). Fable 5.2 scores 49.1% on FrontierCode 2.0, up from 32.4%. API ID: claude-fable-5-2.