Claude Fable 5.1

Trends

• Frontier cyber capability ships to defenders behind gated access
• AI starts producing verified scientific and mathematical results

Items

1. Sep 1

   Anthropic's Claude Fable 5.1 and Mythos 5.1

   One model at two safeguard levels sets new coding marks (Terminal-Bench 4.0 55.8%, 60.9% for Mythos) at ~25% lower typical cost via 75%-cheaper cache reads; Mythos 5.1 is restricted to vetted cyber and life-sciences programs after designing protein binders at a ~50% hit rate.