I misunderstood this comment originally. In principle, Small Transfers (ST) could let a content site bill AI agents per request. Each site (acting as an ST merchant) would expose a simple "content" endpoint. The AI agent (as an ST customer) would perform a headless OAuth flow, after which the content site could charge for access. We currently don't support headless OAuth, but if anyone is interested in exploring this use case, please get in touch.