Glossary
Agentic checkout
Agentic checkout is an AI agent completing a purchase on a buyer's behalf — creating a cart, applying payment, and placing the order through a commerce protocol (ACP or UCP) instead of a human filling out a web form.
A UCP checkout session moves through a state machine (incomplete → ready → completed); when an agent can't resolve something programmatically it escalates to a continue_url where the human picks up. OpenAI's in-chat Instant Checkout pivoted to a redirect model in March 2026, which is why “can an agent actually complete a purchase on your store?” is the question that matters more than “does an AI mention you?”