An open standard for agentic commerce that gives AI agents and merchant systems a shared way to discover products, build carts, complete checkout, and handle post-purchase support. Google announced the Universal Commerce Protocol (UCP) on January 11, 2026, as a vendor-agnostic, open-source protocol designed to work across consumer surfaces, businesses, and payment providers. It is compatible with the Agent Payments Protocol (AP2), Agent2Agent (A2A), and the Model Context Protocol (MCP).
How UCP Works
UCP standardizes the commerce journey through a single integration point rather than a custom connection for every agent or surface. Businesses publish a profile that describes the capabilities they support, such as product discovery and checkout. Agents can then discover those capabilities dynamically and communicate over REST APIs, A2A, or MCP, depending on the merchant’s stack.
- Capability discovery: Agents read a merchant profile to learn which commerce actions are available, including checkout and payment options.
- Checkout paths: Merchants can support native checkout inside an AI surface, transfer a cart to their own site, or, in some cases, use an embedded checkout.
- Payments architecture: UCP separates what a shopper uses to pay (instruments) from the payment handlers that process those payments, so existing processors can participate.
- Extensions: Capabilities can be extended with specialized functions such as discounts, loyalty, or identity linking.
Google’s Reference Implementation
Google published the first reference implementation of UCP to power checkout in AI Mode in Google Search and the Gemini app. Eligible U.S. merchants can let shoppers buy during research, using payment methods and shipping details already saved in Google Wallet. Merchants remain the merchant of record and keep control of customer relationships, data, and the post-purchase experience. Merchant Center provides an integration hub for sandbox testing and production validation, with a gradual rollout that began in the United States and is planned to expand to Australia and Canada.
Why UCP Matters in Martech
For marketers and commerce teams, UCP turns product catalogs, carts, and checkout into interfaces that shopping agents can use without a one-off integration for every assistant. That can reduce abandoned carts when a shopper is already researching in an AI surface, and it keeps the merchant in control of the sale. Teams preparing for agentic commerce should confirm that product data is accurate and complete, decide which capabilities to expose, and understand how UCP sits alongside AP2 for authorized payments and A2A or MCP for agent communication.
