Model Releases
Anthropic unveils Claude Fable 5.1, which is generally available, and Mythos 5.1, for trusted partners and with cybersecurity and life sciences safeguards (Anthropic)
Anthropic: Anthropic unveils Claude Fable 5.1, which is generally available, and Mythos 5.1, for trusted partners and with cybersecurity and life sciences safeguards — We're introducing Claude Fable 5
Anthropic: Anthropic unveils Claude Fable 5.1, which is generally available, and Mythos 5.1, for trusted partners and with cybersecurity and life sciences safeguards — We're introducing Claude Fable 5.1 and Claude Mythos 5.1. They're the world's most advanced models for coding and knowledge work …
Related
- Claude Fable 5.1 and Mythos 5.1 are Anthropic's first models to watermark text outputs; a detection API is available to eligible groups as required under EU law (Ben Patterson/PCWorld)
- Anthropic says it expects Mythos-class models to be available to all customers 'in the coming weeks' following the development of stronger safeguards (Madison Mills/Axios)
- Anthropic updates Claude Fable 5's biology safeguards to reduce false positives, cutting biology-related 'fallbacks' by ~85% in testing across product surfaces (Anthropic)
Source: Techmeme | 2026-09-01