MythosLM

Independent reference. Not affiliated with, endorsed by, or sponsored by Anthropic PBC. Details.

What is Anthropic Mythos?

What is… informational Last reviewed

Same thing, different phrasing

Searchers use "anthropic mythos," "claude mythos" and "mythos ai" interchangeably. They all point at Anthropic's top capability tier, Mythos-class. Anthropic is the company; Claude is the assistant brand; Mythos is the tier above Opus. So "Anthropic Mythos" = "the Mythos-class models from Anthropic."

What's actually in the family

  • Mythos Preview — first Mythos-class model, April 2026, via Project Glasswing.
  • Mythos 5 — June 9, 2026, Glasswing-only, classifiers lifted.
  • Fable 5 — June 9, 2026, public edition with safety classifiers.

All three are above Opus in tier. For the differences between the two June editions, see Fable 5 vs Mythos 5.

Why the naming feels confusing

Anthropic shipped a tier name ("Mythos-class"), a preview, and then two same-model editions within months. Add an internal-rumor codename ("Capybara," now corrected) and it's no wonder the vocabulary is muddy. The glossary untangles each term.

Frequently asked questions

Is "Anthropic Mythos" an official product name?

The official tier name is Mythos-class. "Anthropic Mythos" is a common informal phrasing, not a distinct product. The shipped products are Mythos Preview, Mythos 5 and Fable 5.

Is Anthropic Mythos available to the public?

The unrestricted Mythos editions are Glasswing-only, and the public Fable 5 edition is currently suspended. See availability.

Sources & further reading

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.