Author here.

I’m worried about the same (models tuned for specific harnesses).

We actually work around that by respecting the “contract”. For instance, our harness’ Bash signature is exactly the same as Claude’s. We do our sandboxing stuff and respond using the same format.

In the “eyes” of the model there’s no difference between what Claude does and what we do (even though the implementation is completely different).

We basically use Claude’s tools as API contract