Google started a phased US rollout of a Universal Commerce Protocol integration hub in Merchant Center, which lets merchants put a checkout button on qualifying products that appear in AI Mode and Gemini. Merchants pick which pieces to support, choosing among sending the cart to their own site, letting shoppers pay directly on Google, and linking shopper accounts, instead of accepting one fixed checkout. They have to build the UCP integration first, apply through an interest form, and wait to be selected before they can test in a sandbox. Australia and Canada are now slated for next year, and merchants on third-party platforms are told to ask their provider about UCP plans.
