Anthropic releases safeguarded Fable 5, its first Mythos-class model for public use

Anthropic has released Fable 5, described in multiple reports as its first public Mythos-class model, marking a notable expansion of its most advanced AI systems.

The launch comes with guardrails built into the model. According to the reporting, requests involving high-risk topics such as cybersecurity, biology, chemistry and model distillation are routed to a less capable model instead of being handled directly.

Coverage also says the model is now available to paid Anthropic plans, with a future trusted-access program planned for vetted users who want access to a less restricted version.

The release has drawn attention because the model class has been viewed as especially sensitive by governments, cybersecurity specialists and financial institutions. The company’s approach appears aimed at widening access while keeping tighter control over the highest-risk capabilities.

There is still some inconsistency in how the model is being named in early coverage, with reports referring to it as Fable 5 and Claude Fable 5. The exact official naming and the scope of future trusted access remain unclear from the current reporting.