Until today, Anthropic's Mythos-class models were restricted to a small group of cyberdefenders and critical infrastructure providers. Claude Fable 5 changes that — it's the same underlying model, now available to anyone, at $10/M input and $50/M output tokens.
That's less than half the price of Mythos Preview. And the capabilities are a genuine step change.
"Stripe reported that Fable 5 compressed months of engineering into days. In a 50-million-line Ruby codebase, the model performed a codebase-wide migration in a day that would otherwise have taken a whole team over two months."
What actually changed
New model tier, general access. Fable 5 is the first Mythos-class model available outside Project Glasswing. Mythos 5 (the same model, safeguards lifted in some areas) stays restricted to vetted cyberdefenders via Glasswing's trusted access program.
