Claude Fable 5 and Claude Mythos 5
Anthropic, Tuesday, June 9th, 2026
Anthropic launches Claude Fable 5 for general use and the safeguard-lifted Claude Mythos 5 for vetted security pros.
Anthropic released Claude Fable 5, its most capable generally available model, alongside Claude Mythos 5, a version with lifted safeguards reserved for authorized cybersecurity and research professionals. Fable 5 shows strong gains across software engineering, knowledge work, vision, and scientific research.
The launch adds new safety classifiers that reroute potentially harmful requests to Claude Opus 4.8 and introduces a 30-day data retention policy. Both models are priced at $10 per million input tokens and $50 per million output tokens, with Fable 5 available immediately and Mythos 5 limited to approved partners.