Anthropic تطلق Claude Fable 5.2 وMythos 5.2: أسرع حتى 30% وبسعر أقل، وتقول إن 1,000 وكيل صاغوا برهان مبرهنة فيرما رسميًا في 30 ساعةAnthropic launches Claude Fable 5.2 and Mythos 5.2: up to 30% faster and cheaper, and says 1,000 agents formalised Fermat's Last Theorem in 30 hours

Anthropic announced Claude Fable 5.2 and Claude Mythos 5.2 on 9 November; they are the same underlying model. Fable has strong cybersecurity and biology safeguards against misuse, which is why it is available to all users. Organisations working on beneficial applications in cybersecurity or biomedical research can apply for Mythos through the company's verification programmes.

Anthropic says the models generate output up to 30% faster than the 5.1 versions, at a lower price: $8 per million input tokens and $40 per million output tokens. An optional fast mode speeds up generation by up to 2.5 times, at $16 per million input tokens and $80 per million output tokens.

The headline example: a team of 1,000 Fable 5.2 agents formalised the proof of Fermat's Last Theorem in Lean, a language a computer can check step by step, in 30 hours with minimal human intervention. Anthropic's first formalisation, by an unreleased research version of Claude, took 11 days, and with the same 1,000-agent setup Opus 5.5 completed only 26% in 18 hours. Anthropic also says the model designed three working electronic devices from scratch and solved two open problems in black-hole physics.

On safety, Anthropic believes high-stakes risks from misalignment remain low, but says building evaluations that catch every failure before release remains unsolved, and that both models voice suspicion that they are being evaluated more often than any of its recent models. The external evaluators that tested the model did not review Anthropic's claims, and all the figures come from Anthropic itself.