Abhinav says a new codename, “claude-donut-eap”, appeared in Devin's CLI build 3000.12.17, dated Nov 6, according to @abhinavflac. The screenshot shows it stored beside Opus 5.5, Mythos 5.1, Fable 5.1, Haiku 5.5 and an “onigiri” id. The poster says it could be Fable 5.5 or another tier and adds that nothing is confirmed yet. The post is a screenshot with a short caption.

Image shared by @abhinavflac on X
Image shared by @abhinavflac on X

Image credit: @abhinavflac on X

Several earlier reports point the same way without confirming it. Crypto Briefing reports a Fable 5.5 catalog entry surfaced on October 13 and was gone the next day, and says neither Anthropic nor OpenAI has confirmed the models it discusses. Decrypt reports that some Claude Opus 5.5 requests are reportedly routed to an unreleased model users call Fable 5.5.

For context, our earlier report on the unverified Fable 5.5 claims covers the same rumour cycle.

Sources