Glossary term
Claude Mythos Preview
Also: Mythos Preview
The Claude Mythos Preview was the April 2026 limited release of a Mythos-class model, delivered through Project Glasswing to a small set of selected organizations.
The details
Launched in April 2026 via Project Glasswing, the Preview reached roughly 50 organizations in cyberdefense and critical infrastructure, including US-government participants. Indicative pricing was about $25 / $125 per million tokens.
Its place in the timeline
The Preview preceded the June 9, 2026 public launch of Fable 5 and Mythos 5, serving as the first hands-on exposure to Mythos-class capability.
Sources & further reading
- Anthropic — Fable & Mythos access noticeOfficialanthropic.com
Facts on this page link to their source. Quotes are kept under 15 words and attributed; figures labelled unofficial are third-party until Anthropic publishes system-card numbers.