Google rolls out Universal Commerce Protocol checkout across search results, adding cart, catalog and identity linking

Google has expanded its Universal Commerce Protocol (UCP) to allow users to buy products directly from the main Google Search results page. The new “Buy” button, visible on Wayfair listings and slated for partners such as Shopify, Etsy, Target and Walmart, connects a logged‑in user’s Google Pay account to the retailer’s checkout system. Merchants must maintain a Google Merchant Center account with approved products, set the native_commerce attribute, and provide shipping, return and support details. In addition, a Google Pay & Wallet Console account with a payment provider integrated via the Google Pay API is required, along with a published “/.well-known/ucp” profile and three core REST endpoints for session creation, updates and completion. Early‑access interest forms are also needed to join the rollout.

On March 19 2026, Google announced a major update to UCP that brings the protocol closer to full agentic commerce. The new Cart feature lets AI agents add multiple items to a retailer’s cart in a single operation, replacing the earlier single‑item checkout that required separate transactions. Catalog now allows agents to query live product details—including variants, pricing and stock levels—directly from a retailer’s inventory, moving beyond static Google Shopping feeds. Identity Linking, already part of UCP’s stable release, lets shoppers authenticate via OAuth 2.0 so that loyalty benefits such as member pricing and free shipping are preserved when buying through Google AI Mode. Google also introduced a simplified onboarding path in Merchant Center: products marked with the native_commerce attribute will automatically display a checkout button in AI Mode and the Gemini app, eliminating the need for a full‑blown integration.

The update positions UCP at feature parity with OpenAI’s Agentic Commerce Protocol (ACP), making it a viable option for millions of Merchant Center retailers. Platform partners such as Commerce Inc, Salesforce and Stripe will implement UCP, enabling merchants on those platforms to serve both UCP and ACP without custom integration. The rollout signals Google’s commitment to agentic commerce, where AI agents can research, compare and complete transactions directly from the search interface, and it is expected to streamline the online shopping experience for users while lowering the barrier to entry for merchants.