Visa's Instant Checkout was retired in March after merchant fee problems; the ChatGPT integration rebuilds commerce on Visa's existing card-acceptance rails, removing the per-merchant fee barrier. Visa's press release names three infrastructure layers absent from media coverage: Agent Score, Agentic Directory, and a Large Transaction Model trained on billions of transactions for fraud detection. AP reporting notes most Visa-ChatGPT transactions will require human approval initially, qualifyi...