Anthropic introduced Claude Fable 5.2 and Claude Mythos 5.2 on November 9. The launch announcement describes faster outputs than the 5.1 versions and lower standard API rates. The two products share an underlying model, but access and safeguards differ.
What changed in the two 5.2 releases?
Anthropic says the models generate outputs up to 30% faster than Claude Fable 5.1 and Claude Mythos 5.1. It lists standard pricing of $8 per million input tokens and $40 per million output tokens. The optional fast mode raises those rates to $16 and $80 per million tokens, respectively, for up to 2.5 times faster token generation. Both speed figures are vendor-reported upper bounds.
Who can use Fable and Mythos?
Anthropic makes Fable available to users with cybersecurity and biology safeguards in place. Organizations working on eligible cybersecurity or biomedical research can apply for Mythos through Anthropic's Cyber Verification or Life Sciences programs. The shared base model does not make the two access paths interchangeable. A team should first establish which one it can use for the work it plans to do.
What do the coding results show?
Anthropic's FrontierCode 2.0 test compares whether code changes would be merged by repository maintainers. At High effort, Fable 5.2 scored 45.3%, compared with 45.5% for Opus 5.5 at Max effort. Anthropic reports roughly half the cost per task in that comparison. At Xhigh effort, Fable 5.2 scored 49.1%. Those are results for the specified effort settings and evaluation, rather than a forecast for another codebase.
Anthropic still recommends starting with Claude Opus 5.5 for most coding and knowledge work. It suggests moving to Fable or Mythos when the scope or complexity warrants it. That makes the model choice a question about the task and its review cost, not just a comparison between token prices.
