Bedrock doesn't offer zero data retention for OpenAI's latest models either

> For OpenAI GPT-5.4 and GPT-5.5, classifier-flagged traffic will be retained for up to 30 days for automated offline abuse detection

https://docs.aws.amazon.com/bedrock/latest/userguide/abuse-d...

I think that’s by AWS though. For Fable you need to flip an account wide flag that says “I want to share my prompts with the model vendor.”

The Fable announcement page on the Anthropic site says this data sharing will be applied regardless of the sharing setting of the company account.

https://www.anthropic.com/news/claude-fable-5-mythos-5#a-new...

---

  ## A new data retention policy

  Finally, we’re making a change to the way we handle business
  customer data for Fable 5, Mythos 5, and future models with
  similar or higher capability levels. We will require 30-day
  retention for all traffic on Mythos-class models, on both
  first- and third-party surfaces. [...]

No it says sharing is required. If you don't change the setting on your account then you simply can't access Fable, its not like the setting is ignored. I just tried this on my account and it blocks API requests to Fable.

Interesting. When I tried switching to it yesterday from Opus 4.8 ("/model" command) it didn't complain, but I didn't actually send anything to it when I saw the cost was like 2x Opus 4.8. ie switched back

I'll try to remember to actually try it tomorrow and see what happens.