All terms
Models & Products
Claude Mythos
Anthropic's most capable, restricted frontier Claude tier, limited to approved organizations.
Definition
Claude Mythos is Anthropic's most capable tier of Claude models, sitting above Opus. Access is restricted to pre-approved organizations working on critical infrastructure, while the public Claude Fable shares the same underlying model. Mythos was first offered through Project Glasswing to help find and fix software vulnerabilities.