Anthropic System Card Confirms MyTHOS 5 and Fable 5 Share Weights

Anthropic's system card confirms that Claude MyTHOS 5 and Claude Fable 5 use the same underlying model weights, with follow-up discussion clarifying that the system card states this more precisely than the original Twitter thread.

2026-11-10 ~ 2026-11-10 · 2 related posts

• System card asserts with specificity that MyTHOS 5 and Fable 5 share weights — repligate · 2026-11-10
• System card confirms Claude MyTHOS 5 and Fable 5 share the same underlying weights — repligate · 2026-11-10