Anthropic launches Claude Fable 5.1 and Mythos 5.1

Anthropic launched Claude Fable 5.1 and Claude Mythos 5.1, the same model with different safeguards for coding, knowledge work, and scientific research.

• Fable is generally available now, while Mythos is limited to vetted cyber defenders and life scientists.
• Anthropic also introduced Enterprise Frontier Safeguards and reduced cache read costs.