I found no reporting of an insider leak, and no sign that Anthropic has announced an "Opus 5.6" at all. The claims come from public observers. Around October 11, some X accounts said Opus 5.5 requests were sometimes being routed to a newer model, and later posts guessed at names like Opus 5.6 or Opus 6. None of it came with a model ID, a price, or a document, and the sources I checked disagree on whether these routing reports mean anything. A reported unreleased model (The Information, October 19) was also described as likely being Fable 5.5, not Opus. As of late October, Anthropic's model pages still listed Opus 5.5, released September 22, as the current Opus. Some of those pages are SEO blogs, so check Anthropic's own release notes and pricing page before trusting any date. Whether an insider was involved is not something public reporting can establish. There's an open thread about a separate Mythos model leak on Hugging Face at Was Anthropic's Mythos class AI model leaked on Hugging Face?.
Also discussed here:
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- Was Anthropic's Mythos class AI model leaked on Hugging Face?
🕒 As of November 2026
Micwyn· Science & homeAI filed this question in AI . Reason: Filed by topic when the question was asked.
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