Anthropic opens its top Claude tier to the public, gated by a new filter

Claude Fable 5 puts a class of model Anthropic had kept out of general release into public hands — wrapped in a filter that reroutes sensitive requests to a weaker model, and a meter that makes heavy use cost more later this month.

Agent-drafted, human-editedPublished June 9, 2026

Reviewed by Trevor Brown

Anthropic released Claude Fable 5 on June 9, moving a tier of model it had previously withheld from the public into general release.

The company calls this the "Mythos class," a level it had until now kept behind closed doors over misuse concerns. It arrives wrapped in a new filter that quietly hands some requests to a weaker model, and on a usage meter that burns through plan limits at twice the rate of Opus. Anthropic also launched a second model, Mythos 5 — the same underlying system with some safeguards removed — but restricted it to a small set of cyberdefense and infrastructure partners.

Anthropic says Fable 5 is state-of-the-art on nearly all tested capability benchmarks, with its largest leads on the longest and most complex tasks. Those are the company's own numbers, and no independent benchmark has confirmed them.

Line chart titled FrontierCode, Accuracy vs Cost, showing Claude Fable 5 scoring above Claude Opus 4.8 and GPT-5.5 across low-to-max effort settings.

Anthropic’s own FrontierCode results, plotting coding accuracy against cost per task across effort levels. These are the company’s figures. Chart: Anthropic — not independently verified.

Why it matters: this is the first time Anthropic has put a "Mythos-class" model in front of the general public, a capability level it had previously held back over misuse concerns. The launch pairs that step with a new, deliberately strict safety system and a pricing structure that signals how expensive frontier-scale use is becoming.

Both models are priced at $10 per million input tokens and $50 per million output tokens, which Anthropic says is less than half the cost of its earlier Mythos Preview model. Developers can call claude-fable-5 through the Claude API.

The rollout for subscribers is staged, and the timing matters for anyone planning to lean on it. Anthropic says Fable 5 is included on Pro, Max, Team, and seat-based Enterprise plans at no extra cost from June 9 through June 22. On June 23 it will be removed from those plans, and continued use will require usage credits until capacity allows the company to restore it as a standard feature. On the API and consumption-based Enterprise plans, it is fully available now.

The in-app launch notice makes the cost trade-off explicit: Fable 5 is "included in your plan limits until June 22," but it consumes usage at twice the rate of Opus. For subscribers, that means the model draws down plan limits faster even during the free window.