Anthropic launches public Claude Fable 5

Anthropic's dual-release approach of Fable 5 and Mythos 5 outlines a future where public frontier models are heavily safeguarded and route to fallbacks, while raw, unrestricted intelligence is strictly gated. The split between the restricted Mythos 5 for infrastructure defense and the public Fable 5 sets a new standard for risk management of frontier capabilities. Additionally, seamlessly falling back to Claude Opus 4.8 on flagged prompts represents a major improvement in user experience compared to abrupt refusals, and specifying Fable 5 for long-horizon agentic tasks positions it specifically for asynchronous coding and planning workflows rather than standard chat interfaces.