It is actually worse than that. It is at least 30 days. There is an "almost" that is doing a ton of heavy lifting here "deletion after 30 days in almost all cases". My read of that is they can hang onto data for as long as they want, even if they usually won't. And "all traffic" with an agentic harness is basically your entire codebase you work on.

> We will require 30-day retention for all traffic on Mythos-class models, on both first- and third-party surfaces. We won’t use this data to train new Claude models, or for any non-safety-related purpose, and we’ve instituted new privacy protections including logging all human access to the data and ensuring its deletion after 30 days in almost all cases (see this post for further details). The data will help us defend against complex and novel attacks (including new jailbreaks and attacks that operate across many requests) as well as help us identify and reduce false positives.