Claude Fable 5 and Mythos 5: one Anthropic model, two names, told apart by its safety filters
On 9 June 2026 Anthropic released Claude Fable 5, its first Mythos class model for the general public, and Claude Mythos 5, the same model with some safeguards lifted for vetted cyber defenders. Both cost USD 10 per million input tokens; what sets them apart is a set of classifiers.
