Glossary
Product feed
A structured catalog a store sends so an assistant can show a real price, a real image, and a product page.
A product feed is a file of product rows that a merchant maintains. OpenAI's feed spec requires nine fields for a discovery row: an item id, a title, a description, a product URL, a brand, a seller name, an image URL, availability, and a price. Checkout is a separate integration. Marking a row as eligible does not, by itself, turn on payment.
A shopping agent that quotes a price should be reading a feed like this, or a merchant catalog with the same job, rather than inventing a number. Google's Shopping Graph and Merchant Center are the feed path behind its cart. The payment step that may follow is agentic checkout. Fetching the row is tool use.
The longer guide is Can an AI shopping agent check out for you?.