Agentic agents available from large language models and empowered by credit and debit cardholders to search for products and services on their behalf don’t yet act fully autonomously. Finalizing purchases still involves a second action by the cardholder—approval of the payment. Soon, however, some AI agent-initiated transactions are expected to be fully autonomous, and when that happens, errors in intent and constraint could occur. Errors could include buying the wrong item, buying the correct item but in the wrong size or color and buying from the wrong merchant. American Express is...