Anthropic Releases Claude Fable 5.2 and Claude Mythos 5.2

Anthropic has released Claude Fable 5.2 and Claude Mythos 5.2. The two are the same underlying model; Fable comes with cybersecurity and biology safeguards and is available to all users, while Mythos requires applying through a verification program. The new versions improve on coding, reasoning, and vision, with output speed up to 30% faster than 5.1, priced at $8 per million input tokens and $40 per million output tokens, with an optional fast mode that speeds things up by up to 2.5 times. The company says that on FrontierCode 2.0, Xhigh effort reaches 49.1%, and that 1,000 agents completed a formal proof of Fermat's Last Theorem within 30 hours.