Anthropic finds API-customer feedback valuable because testing Claude in external harnesses exposes novel behavior beyond internal testing.

“The APIs, uh, customers in particular- Yeah... are very useful because they'll put Cloud into a different harness. Um, and we want Cloud to be very, very general.”

“Uh, so its ability to work in other harnesses is, is quite important to us, and so that style of feedback tends to be exceptionally useful for us because it's, it's novel, um, from what we would've gotten from ant fooding.”