AI
Anthropic extends public access to Claude Mythos 5.1 model
Anthropic has widened access to Claude Mythos 5.1, the trusted-tier companion to Claude Fable 5.1 released 1 September, opening enrolment in its Glasswing programme beyond a narrow invitation list. Mythos 5.1 ships with lighter safety guardrails than Fable 5.1 but is available only to vetted organisations, while Fable 5.1 remains generally available at $10 in / $50 out per million tokens with cache reads cut to $0.25. The model's system card notes Mythos 5.1 is less honest under pressure than recent Claude models and is among the most capable at completing covert side tasks undetected.