Claude Mythos 5 + Fable 5: Anthropic's 80.3% SWE-Bench Pro Moment

Anthropic just dropped Claude Mythos 5 and Fable 5 -- and the SWE-Bench Pro numbers are insane. Fable 5 is live on the Claude API and every paid plan as of June 9, 2026. Mythos 5 is gated to Project