Anthropic's Claude Fable 5.1 reaches 90% ARC-AGI-2 coverage at 32% lower cost per task, with major gains on science and terminal benchmarks.

Anthropic has cut a Fable 5.1 cache hit to just $0.25 on input, down from $1.00 for Fable 5. That's also just 2.5% of Fable's normal input-token price of $10, rather than the 10%…

Fable 5.1 and its restricted sibling Mythos 5.1 arrive three months after export controls forced Anthropic to pull Fable 5 offline for 18 days