Anthropic launches Claude Fable 5.1 as AI competition heats up

Anthropic has released Claude Fable 5.1, a new version of its frontier model that the company says improves long coding tasks, research, and general knowledge work while reducing some of the safety refusals that users criticized in Fable 5. According to the newsletter, the model leads a major benchmarking index and is reported to be more efficient on typical tasks, though some higheffort jobs may still cost more because the system produces more output. Anthropic also introduced a less restricted version called Mythos 5.1 for screened U.S. researchers working in cybersecurity and biology. The launch comes as the AI market enters a new round of releases after a quieter summer. The newsletter also notes that OpenAI’s next Astra update is expected soon, and that the broader debate over AI safety and regulation continues to intensify.