Claude Mythos
Mar 29, 2026
Claude Mythos
Claude Mythos(Opus 5) Leaked: What happened and What to expect
Claude Mythos, internally codenamed Capybara and positioned as the next tier above Claude Opus (potentially Opus 5 equivalent), is Anthropic’s unreleased flagship AI model. Leaked draft documents reveal it delivers “dramatically higher scores” than Claude Opus 4.6 in software coding, academic reasoning, and cybersecurity. It represents a “step change” in capabilities and is currently in limited early-access testing due to unprecedented cybersecurity risks.