Google turned on Universal Cart in the United States. A shopper can now fill one cart with items from several different stores inside Google Search, including AI Mode, and inside the Gemini app, then either pay there with Google Pay or arrive at your site with the cart already filled. You stay the seller of record either way. If you sell to American customers, that is a new door into your checkout, and it opened right before the holiday season.
Google names Nike, Sephora, Target, Ulta Beauty, Walmart, Wayfair and many Shopify merchants as participating. Shoppers also get alerts when a saved item drops in price or comes back in stock, so sitting in that cart keeps you in front of someone who already wanted your product.
Two ways the cart reaches you
Native checkout finishes the sale at Google. Cart Transfer sends the shopper to your site with the items pre filled. If you meet Google’s onboarding requirements you pick one of the two in the UCP integration hub in Merchant Center. UCP is Google’s Universal Commerce Protocol, the set of rules that lets Google’s cart talk to your store’s cart.
Transfer is one way in this first release. It creates a cart on your system and nothing more. Updating, deleting or syncing cart contents between Google and your store is not supported, so treat a transferred cart as a snapshot and let your own site check stock and price on arrival. Native checkout is a separate interface and is not required if you only want the transfer.
On Shopify, check one setting
Direct Checkout is on by default for eligible US Shopify stores. Shopify says Google Analytics and Custom Pixels do not fire when a customer buys through Direct Checkout, which means those sales will be missing from your usual reports. You can see the switch under Sales channels, then Agentic, in your Shopify admin.
For numbers, the UCP Analytics Reporting dashboard in Merchant Center follows clicks on the Buy button through purchases and cancellations. The Merchant API also exposes cart transfer counts and average cart value at transfer, and that reporting is in alpha.
The limit to plan around: this is the United States only. Google’s help page says the integration hub is rolling out gradually there, with Australia and Canada next year, and there is no timeline for YouTube or Gmail.
