MythosLM

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How to Access Claude Mythos

Access & preview informational Last reviewed Updated

The short version

"Accessing Claude Mythos" really means choosing between two doors. The unrestricted Mythos editions — the April 2026 Preview and Mythos 5 — live behind Project Glasswing, a selection-based program you cannot self-serve into. The public door is Fable 5, the same underlying model shipped with safety classifiers, which Anthropic offered through the Claude API and cloud marketplaces.

Path 1 — Project Glasswing (Mythos editions)

Glasswing is an invitation-only program concentrated in cyberdefense and critical-infrastructure work, with US-government involvement. Roughly 50 organizations were selected for the Preview. You do not apply through a pricing page; participation is arranged directly. See Project Glasswing access for how selection works.

Path 2 — Fable 5 (the public edition)

When not suspended, Fable 5 is generally available on the Claude API, the Claude Platform on AWS, Amazon Bedrock, Google Cloud, and Microsoft Foundry. It carries classifiers (cyber, bio/chem, distillation) that reroute a small share of flagged requests to Claude Opus 4.8, and the user is told when that happens.

The catch: access is suspended right now

On June 12, 2026, a US export-control directive suspended access to both Fable 5 and Mythos 5. That suspension is currently active, so the normal paths above are paused. Always confirm against the official notice and the live status page before planning around availability.

Frequently asked questions

Can I just sign up for Claude Mythos like Opus or Sonnet?

No. Mythos-class access has never been open self-serve. The Mythos editions run through Project Glasswing, and even the public Fable 5 edition is presently suspended under an export-control directive.

Is Fable 5 the way most people would reach Mythos-class capability?

Yes — Fable 5 is the public, safeguarded edition built on the same model as Mythos 5. It was the realistic route for general users, but it is currently paused.

How do I know when access reopens?

Watch Anthropic's official access notice and the live status page. Both are linked in the sources below and reflect the current suspension.

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.