Spend Theater

Vaulted Checkout, with Spend Theater AI agents are starting to buy things, and finance teams can’t hand an agent a company card or approve every $1.50 purchase by hand. Vaulted Checkout lets an agent ask to pay while only a Basis Theory vault (https://basistheory.com/) can sign, and only inside fixed rules: who can be paid and how much per payment. The wallet key never touches the agent, the spend service, or any AI session. Payments settle in USDC on Base Sepolia, for example https://sepolia.basescan.org/tx/0xd026fed37c35078edc3254ef5aa7b7c52af4492b77ae777ccdfb7a226e07fb5a (1.5 USDC). Our recorded outcomes come from a real run: that settlement, and a refusal (rule_payto) for a wrong payee, assembled into an event log with synthetic timings. Spend Theater is where Gemini 4 Argon does its work. Argon generates a first-draft 3D film of the payment log in one pass, watches its own rendered video, critiques it against the goal, and repairs the scene, in a loop. A frozen evaluator that Argon cannot edit counts contradictions against the log, and the scoreboard keeps every round. In one clean run, errors went from 2, to 2 different errors, to 0, ending with a critic pass. The result is a film an operations person can watch to see what an agent tried to spend, and what the vault allowed, from the log.