I and some other people noticed a potential discrepancy in Anthropic's announcement of Claude Mythos. The version of the RSP that was operative over the relevant period of time (3.0) included a section (3.1) that suggested some internal deployments would require Anthropic to publish a discussion of that model's effect on the analysis in their previously-published Risk Reports within 30 days.

A separate issue that Claude Opus noticed while I was writing this post is that Anthropic's release to "a small set of external customers via a limited research access program" counts as a public deployment, which would trigger the same publishing requirement immediately. I will argue this one first, since I think the case here is stronger.

Did Anthropic mess up?

tl;dr: they probably messed up on the public deployment thing, and it's unclear whether they messed up on the 30-day internal deployment thing. My guess is that Anthropic would argue they're in the clear on the 30-day one, but this depends on some interpretations that are at least slightly favorable to them. I don't know how they'd argue the public deployment one. Relatedly, the RSP has some gaps and ambiguities that should probably be fixed. In some [...]

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Outline:

(01:36) Requirement to publish discussion when publicly deployed

(02:52) Requirement to publish discussion within 30 days of a qualified internal deployment

(03:56) List of RSP Issues

The original text contained 2 footnotes which were omitted from this narration.

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First published:
April 9th, 2026

Source:
https://www.lesswrong.com/posts/F5uxhFrNHLzmNgyqg/anthropic-did-not-publish-a-risk-discussion-of-mythos-when

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Narrated by TYPE III AUDIO.

“Anthropic did not publish a “risk discussion” of Mythos when required by their RSP” by RobertM

LessWrong (30+ Karma)

“Anthropic did not publish a “risk discussion” of Mythos when required by their RSP” by RobertM