Google has just published a support documents dedicated to its new Universal Commerce Protocol (UCP)As a reminder, this standard aims to unify exchanges between merchants, payment systems and artificial intelligence agents. The American giant clearly positions UCP as a central infrastructure for a future "agentic" commerce — that is, automated by AIs capable of buying on behalf of users.
Key takeaways:
- UCP is an open standard that facilitates communication between AIs, online merchants and payment services.
- The UCP checkout will allow customers to complete a purchase directly on Google while keeping the merchant as the official seller.
- The main objective: reduce friction in the purchase journey by relying on Google Pay and the data already stored in Wallet.
- Limited rollout: for now reserved for certain merchants based in the United States via an early access program.
UCP, the new language of online commerce
Announced earlier this year, Universal Commerce Protocol (UCP) is presented as a open standard for agentic commerce, that is, a set of rules allowing intelligent agents (such as those from Google Gemini or from AI mode in Google Search) to interact frictionlessly with online stores.
Concretely, UCP serves as a common language between:
- Merchant websites and their backends,
- AI agents acting on behalf of the user (e.g., recommending, comparing, or buying),
- Payment providers such as Google Pay or other compatible PSPs.
The protocol is interoperable with other existing standards in the ecosystem, notably Agent-to-Agent (A2A), Agent Payments Protocol (AP2) and Model Context Protocol (MCP).
It therefore enables different agent systems to understand each other, exchange product information, handle payments and even manage post-purchase follow-up.
A simplified checkout within the Google ecosystem
Thanks to the integration of UCP, Google is introducing a new payment button directly within Search's AI mode and on Gemini. This button will allow a customer to purchase a product without leaving the Google interface.
Unlike the existing buy button, which redirects to the merchant's site, the UCP checkout happens entirely on Google, while keeping the merchant as the seller of record. The user will make their payment via Google Payusing the payment methods and addresses already saved in their Google Wallet.
Result: fewer steps, more security and a potentially reduced cart abandonment rate.
A managed integration for merchants
Merchants wishing to participate must:
- Fill out an interest form via the Merchant Center according to the criteria published by Google.
- Structure their product listings with the native_commerce attribute, required to enable the purchase button.
- Ensure that their payment provider (PSP) accepts Google Pay tokens. The majority of processors already compatible with the Google Pay API support this.
Google specifies that Merchant Center remains the central tool for managing product feeds and brand assets. The better structured the product data, the smoother compatibility with UCP and the AI checkout will be.
A step toward AI-driven e-commerce
With UCP, Google is clearly preparing the future of a commerce driven by AI agents.
In the long term, these agents could:
- Search for a product according to your constraints (budget, timeframe, brand preference),
- Automatically compare the best offers,
- And complete the purchase without leaving the Google interface.
UCP therefore acts as the technical backbone of this experience, allowing systems to exchange data in a standardized, reliable and secure way.
The article “Google says more about Universal Commerce Protocol (UCP), its new standard for agent-driven e-commerce” was published on the site Abondance.
