Apparently, you won't be able to use Mythos OR Fable for coding. From their announcement...

> routine tasks like coding and debugging will fall back to Opus 4.8.

It was likely a dealbreaker for Anthropic, since the export control excluded Anthropic’s own foreign employees from being able to access Mythos internally. Naturally, this makes model development hard.

Presumably they reached a backdoor agreement.

Presumably there are different levels of safety. I assumed Fable was a nerfed Mythos, and not just via safety harnesses but actual model degredation.