Anthropic introduces two faces of the same innovation today: Claude Fable 5, a Mythos-class model tuned for general use with strong safeguards, and Claude Mythos 5, which runs on the same engine but relaxes some restrictions for trusted cyber defenders and researchers. What does this mean for developers, researchers, and curious users like you? Let's break it down.
What are Fable 5 and Mythos 5
Claude Fable 5 is a Mythos-class model adapted for general use: it delivers the best performance Anthropic has publicly offered so far, standing out in programming, knowledge work, computer vision, and research tasks. In long, complex tests, its advantage over earlier models grows.
Claude Mythos 5 uses the same base model but lifts safeguards in specific areas (mainly cybersecurity and some scientific uses). Mythos 5 is being rolled out first through Project Glasswing with government and security partners; the plan is to extend access via a trusted access program.
