Claude Mythos Blog

Claude Mythos Preview is coming: Can I use this top-of-the-line model now?
Apr 8, 2026
Claude Mythos

Claude Mythos Preview is coming: Can I use this top-of-the-line model now?

Claude Mythos Preview, Anthropic's next-generation cutting-edge model, is also the most powerful model trained by Anthropic to date. Its benchmark scores completely outperform the previous generation, Opus 4.6. However, this model will not be publicly released at this time. Anthropic has chosen a completely different release approach: only allowing a select few partners to use it, and only for one purpose: finding vulnerabilities.
Claude Mythos(Opus 5) Leaked: What happened and What to expect
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.