Claude Fable 5
AnthropicJune 9 Mythos-class debut; now #2 overall at 60 after Opus 5. Briefly export-paused in June, restored June 23.
- Intelligence Index: 60
- Humanity's Last Exam: 53%
- Mythos-class safeguards
- 1M+ context · Adaptive Reasoning
- Released 2026-06-09