Universal Commerce Protocol (UCP)
The Universal Commerce Protocol (UCP) is Google's open standard for agentic commerce. It gives AI agents and stores a shared way to exchange products, prices, carts, checkout, payments, and order status across the shopping journey.
How it works
UCP is Google's answer to the same problem ACP solves for OpenAI: a common set of rules so agents, stores, and platforms can talk to each other about products, carts, checkout, and orders. It spans the whole journey from discovery to post-purchase, and it is designed to work alongside related standards for payments and agent-to-agent communication rather than replace them.
ACP vs UCP
The two big commerce protocols today are OpenAI's ACP and Google's UCP. They are not rivals you have to choose between as a store owner. Because your platform and feed tools handle the plumbing, a store can end up supported on both, the same way a page can be indexed by more than one search engine. The comparison of ACP, UCP, and MCP sits on the ACP page.
A commerce example
When a shopper uses Google's AI shopping surfaces, UCP is part of how your products, prices, and availability reach that answer, typically through Google Merchant Center and your platform's integration. If your Merchant Center feed is incomplete, UCP still carries it, just with less for the agent to work with.
What this means for your store
Like ACP, this is platform-level plumbing you rarely touch directly. Keep your Google Merchant Center feed and your product data complete and current, and the protocol does its job. The lever you control is the quality of the product feed, not the protocol itself.