Anthropic launches Claude Fable 5 and restricted Mythos 5

Anthropic launched Fable 5 for general use and Mythos 5 for a small group of Project Glasswing cyber-defence and infrastructure partners. The models share an underlying system, but Mythos has safeguards lifted in restricted areas.

The split is a useful governance pattern: access to higher-risk capabilities can be tied to a specific defensive purpose, partner group and control framework rather than opened universally.