So that's what it is. Reading its README I thought it was another harness like Pi [1], but with built-in memory so it remembers what it learns, and gets more capable the longer it runs.
Like Letta [2], Dirac [3][4] and the other "more experimental harnesses that look interesting but I haven't had time to try out".
The correct implementation of this condition by Anthropic on the server side would be to block usage by non-Claude apps via Claude's authentication mechanism, and allow it via the per-token API key billing.
Instead of a simple 403 error, which would block usage, they silently redirect to a different billing bucket, which is not ethical behaviour especially since it is based on fuzzy heuristics.