Airline checkout blocks AI booking agents because it cannot verify who they act for

United's stance on AI agents booking flights is better read as a question of identity than of agent competence, the author argues. Booking systems cannot tell a human-delegated agent apart from a scripted bulk booker or fraud traffic, so they block anything that does not resemble a person in a browser. Because every signal the checkout evaluates concerns the client rather than the principal it serves, even a flawless agent is treated like abuse. The author expects scoped, revocable credentials tied to a verified human to become a product requirement, starting with travel and spreading to other sectors. Such credentials would include a verified subject, a key-pair-bound actor, narrow scopes, intent binding, short lifetimes, spend caps, and a revocation mechanism, while the unresolved issue is who bears liability for mistakes.