Changes from previous version
Successor to Mythos Preview with comparable or stronger capability at less than half the preview pricing ($10/$50 vs $25/$125 per million tokens).
Release Summary
Same underlying model as Claude Fable 5 with cyber safeguards lifted for vetted partners. Strongest cybersecurity capabilities of any model in the world at launch, deployed through Project Glasswing as an upgrade to Mythos Preview. Restricted to Glasswing partners initially, with a broader trusted access program planned. API pricing at $10/M input and $50/M output.
Timeline
June 9, 2026
Claude Mythos 5 released
Anthropic upgrades Project Glasswing partners from Mythos Preview to Mythos 5, with plans to expand trusted access for cybersecurity and biology researchers.