Anthropic introduced Claude Fable 5.2 and Claude Mythos 5.2 on Nov. 9, 2026, pairing two versions of the same underlying model with different safeguards and access rules. The company’s launch announcement promises improvements in coding, reasoning and vision, plus faster output at lower listed token prices.
The practical distinction is which work each version will accept. Anthropic says Fable’s cybersecurity and biology safeguards allow broad availability, while Mythos is available to vetted organizations working in those fields.
Same model, different permissions
At launch, Anthropic made Fable 5.2 available across its platforms, including Amazon Web Services, Google Cloud and Microsoft Azure. Developers using the Claude Platform can select claude-fable-5-2.
According to Anthropic, Fable’s safeguards block high-risk cybersecurity activities and most research-biology tasks. Blocked requests receive responses from other Claude models instead. Organizations pursuing beneficial cybersecurity or biomedical applications can apply for Mythos access through the company’s Cyber and Life Sciences Verification Programs.
There is also a separate route through a specific product: Anthropic says Enterprise customers can use Claude Security, whose model family now includes Mythos 5.2, without belonging to the Cyber Verification Program. That is access through Claude Security, rather than general-purpose Mythos access.
Standard prices and a faster, pricier option
Anthropic lists standard pricing for both models at $8 per million input tokens and $40 per million output tokens. It describes those rates as lower than their predecessors’ and says the models generate outputs up to 30% faster than Fable 5.1 and Mythos 5.1.
