Claude Fable 5.2 and Mythos 5.2 arrive faster and cheaper than 5.1

Anthropic released Claude Fable 5.2 and Claude Mythos 5.2, its models for the hardest technical work, with improvements in coding, reasoning, and vision.

Fable 5.2 is available on all paid Claude plans, in the Claude Platform API, in Claude Code, and on the major clouds. Anthropic says it runs up to 30% faster than Fable 5.1, and the price drops to $8 per million input tokens and $40 per million output tokens, from $10 and $50. A fast mode runs about 2.5 times faster at twice the price.

Fable and Mythos are the same underlying model. Fable ships with safeguards, while Mythos is offered through application programs for cyber and life-sciences work.

For the launch, Ultra and Team Premium plans get a Fable usage reset, and Pro and Team Standard get a week of Fable. Anthropic still recommends Opus 5.5 for most everyday work. If you build on the API, the What's new page lists the breaking changes to check before you move off 5.1.

By Anthropic's account the new models are a step above Opus 5.5, and 1,000 Fable agents formalized Fermat's Last Theorem in 30 hours.