Google has launched the Universal Commerce Protocol (UCP), an open standard that enables AI agents to shop autonomously. The protocol was developed with Shopify, Target, and Walmart and forms the basis for new features in AI Mode and the Gemini app.
Today’s consumers expect seamless transitions between different stages of shopping. To support this, there are real-time inventory checks, dynamic pricing, and instant transactions. Companies have to build separate connections for each platform that supports these features, which creates integration issues.
Google developed UCP in collaboration with industry partners to address this bottleneck. The protocol standardizes the entire commerce journey, from product discovery to order management, through a single secure abstraction layer. This eliminates the need for companies to maintain separate integrations for each channel.
Benefits for the commerce ecosystem
For businesses, UCP means they can present their products and services on different consumer interfaces (e.g., AI Mode in Google Search and the Gemini app). Retailers retain full control over their business logic and remain Merchant of Record. The protocol offers an embedded option that allows businesses to maintain their fully customized checkout experience.
AI platforms can offer agentic shopping to their users through UCP. They simplify company onboarding through standardized APIs, while allowing companies to use the Model Context Protocol, Agent2Agent, or their choice of existing agent frameworks.
Payment providers benefit from the open, modular payment handler design, which enables interoperability and choice of payment methods. Each authorization is supported by cryptographic proof of user consent.
How does the protocol work?
Companies publish the services they support via a standardized JSON manifest at /.well-known/ucp. AI agents can thus dynamically discover which functionalities are available, without hard-coded integrations. This allows agents to view information about endpoints, payment configurations, and specific capabilities such as checkout, discounts, and delivery.
UCP models a unique payment architecture in which payment instruments remain separate from payment handlers. This allows the protocol to scale to different existing payment providers. Companies and agents choose which method best suits their platform.
The technology offers flexibility. For example, a checkout functionality can be available via a REST API binding or an MCP binding, depending on the platform’s needs. Extensions enable expanding basic functionality with specialized features, such as discount systems.
Practical implementation
Google offers a reference implementation via Python SDKs and sample repositories on GitHub. Developers can set up a local business server with an SQLite database for testing purposes. The sample implementation demonstrates how agents can discover business opportunities, create checkout sessions, and apply discounts.
A typical workflow starts with setting up a business server with sample products. The server is then configured to accept requests from agents. Agents can discover the available services and capabilities via the /.well-known/ucp endpoint. After discovery, they can create and update checkout sessions, for example by applying discount codes.
To implement via Google’s reference platform, businesses must have an active Merchant Center account and offer products that are suitable for checkout. This ensures that Google has the necessary product information to display inventory within conversational experiences. The checkout feature uses Google Pay, allowing consumers to use payment and shipping information already stored in Google Wallet.
Security and governance
UCP’s security-first approach provides tokenized payments and verifiable credentials as a secure communication method between agents and business backends. The protocol respects existing compliance requirements and governance rules of organizations.
The extensible architecture, with flexible options and an extension framework, scales with new agentic experiences. This design principle also allows UCP to expand into other sectors.
Open-source collaboration
UCP is an open-source project developed with more than 20 companies. In addition to Google, Shopify, Etsy, Wayfair, Target, and Walmart, Adyen, American Express, Best Buy, Flipkart, Macy’s, Mastercard, Stripe, The Home Depot, Visa, and Zalando also endorse the protocol.
Google invites developers, companies, and platform architects to contribute to the future of commerce. The specification is available on GitHub, where participants can contribute via GitHub Discussions and pull requests.
Companies wishing to integrate with Google’s implementation can consult the integration guide and fill out a merchant interest form via Merchant Center. Full UCP integration instructions are available via the official documentation.
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