Anthropic Mythos in 2026: a year-in-review

The big picture

2026 is the year Anthropic introduced a model tier above Opus: Mythos-class. The arc has three acts — a quiet preview, a public launch, and a policy-driven suspension — and understanding them in order makes the rest of this wiki click into place.

Act one: the April Preview

The first Mythos-class model arrived as the Mythos Preview in April 2026, distributed through Project Glasswing to roughly 50 vetted organisations in cyberdefense and critical infrastructure, including US government users, at about $25/$125 per million tokens.

Act two: the June 9 dual launch

On June 9, 2026, Anthropic released two editions of the same underlying model: Mythos 5, Glasswing-only with classifiers lifted, and Fable 5, the public edition with safety classifiers on. Fable 5 brought a 1M context window, up to 128k output, $10/$50 per million tokens after intro pricing, and broad cloud availability — free to subscribers from June 9 to 22.

Act three: the June 12 suspension

Then policy intervened. A US export-control directive on June 12 suspended access to both June editions, a suspension that remains active. Anthropic intends to restore Fable 5 when capacity and clearance allow; track the current state via the live status page.

Where the lineup stands

Below Mythos sit Opus 4.8 ($5/$25), Sonnet 4.6 ($3/$15), and Haiku 4.5 ($1/$5). For now, Opus 4.8 is the practical ceiling most users can reach.