In the emerging architecture of AI-driven commerce, Amazon has drawn a boundary — blocking Meta's autonomous shopping agent, Muse, from transacting on its platform. The conflict is not merely corporate rivalry but a deeper contest over who owns the relationship between a buyer and the marketplace, and whether that relationship can survive the arrival of a machine intermediary. As AI agents grow capable of acting on human behalf across the open internet, the gatekeepers of commerce are discovering that convenience for the user may come at the cost of control for the platform. This moment may be