I think the problem is clear. Anthropic saw their usage go up much more than their capacity could handle. There are a few tried and true solutions to this, like "increase the price" or "restrict signups so you can guarantee service to what you have already sold".
Then there is the "large scale fraud" option, where you materially change and degrade the service you have already sold. Just because you have obfuscated and mislead in how you describe the product you are selling doesn't mean you get to capture the cash flow of 1 year subscriptions then not honor that contract for the full duration.
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.
I think part of the issue is they were letting people use plan's API for random stuff, so people could do testing or small projects. Then the agents came along and exploded the cost, so they want to restrict those but still let some other usage, which I don't think is tenable.
I'm sure there is some way that they could enforce that all calls are coming from the Claude app or Claude Code. It might be hard to 100% enforce, with stuff running on a user's machine, but they could still could make it quite difficult, where someone has to be intentionally trying beat the system (like stealing encryption keys out of the Claude Code binary or something).
That specific nature would mean it would get caught by even the most cursory of code reviews.
Even if I was just "scanning my eyeballs over the code" without properly reading it, this would jump out as very odd and make me pause.
I think they wanted to try not to totally lock down the monthly plan for non-agent uses, but that makes it all too fuzzy. They should use some specific method like encrypted signatures or something, so that anything sending to the monthly plan that isn't Claude Code or the desktop Claude app just errors out and be done with it.