News: AI safety
Claude Fable 5.1 and Mythos 5.1 release on September 1, 2026
Claude Fable 5.1 release: Anthropic shipped Fable 5.1 and Mythos 5.1, one model with two safeguard levels, on Sep 1.
OpenAI outlines safety cases for frontier AI training on Sept 28, 2026
On September 28, 2026, OpenAI said frontier AI training runs should need a written safety case before they continue.
Anthropic Claude Opus 5.5 release on September 22, 2026: what's new
Claude Opus 5.5 release: Anthropic shipped the model on September 22, 2026, at Fable 5.1 level on most work.