Anthropic has released Claude Fable 5.1 and Claude Mythos 5.1, the same model behind two different safeguard layers. Fable 5.1 scores 52.6% on Terminal-Bench-Science 0.1 against 24.7% for Fable 5, ships a 1M token context window, and drops cache reads 75% to $0.25 per million tokens while base pricing holds at $10 and $50.
Anthropic has released Claude Fable 5.1 and Claude Mythos 5.1, the same model behind two different safeguard layers.
Fable 5.1 scores 52.6% on Terminal-Bench-Science 0.1 against 24.7% for Fable 5, ships a 1M token context window, and drops cache reads 75% to $0.25 per million tokens while base pricing holds at $10 and $50.
Three API changes are breaking, including the removal of forced tool use.
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Anthropic has released Claude Fable 5.1 and Claude Mythos 5.1, the same model behind two different safeguard layers. Fable 5.1 scores 52.6% on Terminal-Bench-Science 0.1 against 24.7% for Fable 5, ships a 1M token context window, and drops cache reads 75% to $0.25 per million tokens while base pricing holds at $10 and $50. Three API changes are breaking, including the removal of forced tool use.
Three API changes are breaking, including the removal of forced tool use.
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