This is the problem we've been working on solving with WorkOS Radar. We run it for Cursor and a bunch of other AI companies who have a free trial that gives some free inference to test the product.
It turns out to be a pretty complex program to solve at scale. Token fraud is a lucrative market and the adversaries are surprisingly sophisticated. It's a cat-and-mouse game, accelerated with AI.
(If you'd like to work on this, we are hiring :))