An unreleased Claude, claude-onigiri-eap-2, shows up in Artificial Analysis's code

Artificial Analysis's website code now carries a Claude model that Anthropic has not released: claude-onigiri-eap-2. We read it in the site's JavaScript at 10:50 UTC on October 15. It comes in four effort levels (low, medium, high and xhigh) and sits in the same table as claude-fable-5, claude-fable-5-1 and claude-opus-5-5, with the same fallback model, claude-opus-4-8. @LuminaBench found it first and thinks it is Fable 5.5. That part is unconfirmed.

WHAT IS SOURCED

The slug and its four variants, in Artificial Analysis's own front-end code. Sixteen Claude slugs in that table fall back to Opus 4.8, and onigiri is the only one with no public model behind it. "EAP" is commonly read as early access program, and the -2 may mean a second build. Nobody has said so.

THE AZURE ROW THAT CAME AND WENT

On October 13 at 12:27 UTC, LiteLLM's catalog bot added azure_ai/claude-fable-5-5. It said Azure's Models API in eastus2 listed the model as generally available, with a deprecation date of December 5, 2027. No source gave a price, so the row copied Fable 5.1's. On October 14 at 16:17 UTC, LiteLLM removed it: an audit found no such model on Azure, and a test call returned 404 DeploymentNotFound. Both changes are public on LiteLLM's GitHub (PRs 46201 and 46428). @Mr_Salio flagged the removal on X.

LAST TIME

Opus 5.5 had an EAP codename too. On September 21, an X account relaying a leaker tied claude-wafer-eap to the next Opus, and Opus 5.5 shipped the next day. Anthropic never confirmed that codename.

WHAT WE DO NOT KNOW

Whether onigiri is Fable 5.5, a different model, or an internal test. Anthropic has said nothing about Fable 5.5. OpenRouter still lists only Fable 5 and 5.1, and models.dev has no Fable 5.5 id (both read October 15). Our radar alerts the minute any fable-5-5 id answers in a public catalog. The codename is deliberately not in that pattern, because an early-access id is not a release.