🚨ALERT: Google Quadruples-down on UCP/Agentic Commerce Introduces: Multi-item Carts, Catalog End Point, Loyalty + More! ..While ChatGPT Focuses on...Discovery? 🤔

Google drops the proverbial hammer 🔨 ! Announces four major UCP updates in an already busy Q1 that saw the introduction of UCP (Jan), then it went live (Feb) and now 4 'upgrades' (March).

Happy UCP/Google Day…

Welcome to Google/UCP day here at Retailgentic! 😄 First, this morning we are out with breaking news on UCP/Agentic Commerce and as fate would have it, we also have an incredible podcast dropping later today with Google’s VP/GM of Merchant Shopping (aka Captain UCP@Google), Ashish Gupta. Stay tuned for that, it’s a banger and a great compliment to today’s news and a perfect warm-up for Shoptalk.

To tee the pod up propertly, let’s jump deep into the news that Google just broke.

Today’s Big UCP News

On a blog post, here, titled: “AI shopping gets simpler with Universal Commerce Protocol updates.” Ashish announces four, count them four, major updates to UCP and the Google program(s) around it.

The new features are:

• Multi-item cart capability

• Enhanced catalog endpoint

• Loyalty program integration (via a capability called ‘Identity Linking’)

• The launch of a self-service merchant center

Let’s dig into each of these in detail.

Editorial note: Deep Agentic Commerce Nerds like, ahem, your's truly are watching the UCP github like hawks and have seen these pop up so we had a bit of an idea something was up, that being said, seeing some draft things on a github is one thing, getting a message from ‘Captain UCP@ Google’ is another. We also have more context on Google’s plans around the capabilities thanks to the blog post.

UCP Multi-item Cart

As a refresher, we’ve talked a TON about multi-item/multi-merchant cart and it’s importance for Agentic Commerce to really make any economic sense for the merchant and add value for the consumer to unlock all the ‘cart goodies’ that come along with this capability (lower shipping, free shipping unlocks, etc.)

Also as a reminder, we found evidence that ChatGPT has a multi-cart capability, we’re not sure what they are going to do with that now that they are focusing more on discovery. Also note in this post we went deep into the matrix of multi-item vs multi-merchant carts and aren’t going to repeat all that here, but I do want to re-post the quadrant diagram so it’s fresh in your mind:

Google/UCP’s Cart News

Ashish starts off with:

UCP can help make online shopping more intuitive and convenient, thanks to a new Cart option that will let agents save or add multiple items to a shopping cart at once from a single store – just as a shopper typically would.

As a reminder, UCP is a two sided coin with a front-end and a back-end. By having something in the protocol, in no ways guarantees that Google or other UCP builders will utilize that capability.

On the UCP side you can go here and learn all about it. As demonstrated live in last week’s podcast with Vendee Labs , there was nothing in UCP from stopping someone from building a multi-item/multi-merchant cart on top of the basic protocol, but this beefs up the protocol and gives it a cart back end. This means less work on the front-end and also a standard way that agent builders and merchants can build, process, and checkout carts vs. a wild-west of different scenarios.

Unfortunately, Ashish did not mention if/when we’ll see multi-item carts on the Google user interface (AI Mode is usually where these debut) side, but I’ve got to guess this one is coming soon. We’ll keep our eagle eyes 👀 on the lookout.

Enhanced Catalog Endpoint News

Back to Ashish:

UCP adopters will be able to access a new Catalog capability that lets agents retrieve select real-time product details from a retailer’s catalog where necessary — like variants, inventory and pricing.

Because e-commerce is so dynamic - prices and stock levels changing (at the variant level where it gets super complicated), this is a critical feature to improve the user experience. Now agent builders using UCP can have a more interactive user-experiences. For example, let’s say a shopper is looking at adidas women’s shoes in size 6 and the SKU she looking out is now sold out in that size, the agent builder can call this endpoint and say - “quick, I need all the in-stock size 6’s women’s running shoes” and now you can say: “I’m sorry Sarah, here’s some alternatives and I have verified they are in stock.”

This level of functionality is starting to get waaaaay beyond what we saw in the marketplace era of ecommerce and I’m 100% here for it - this is how Agentic Commerce creates significantly better experiences - with deep back-end integration.

It’s going to be interesting to see how , on the front-end UX, Google utilizes these endpoints -we’ll be on the lookout for examples.

New Loyalty Program Integration (Identity Linking)

Here are Ashish’s comments on this one:

Building on existing standards, UCP will also support Identity Linking. That allows shoppers on UCP-integrated platforms to receive the same loyalty or member benefits they would on a retailer’s site when they’re logged in — like pricing or free shipping — making shopping more connected across the web.

Like Multi-item cart, I believe that loyalty program integration has been a huge friction point not only for the obvious merchant-side, but also on the shopper side. If I’m a loyal Walmart+ subscriber, I’m not going to checkout without that and have down-graded shipping- I paid for up-graded shipping - WTH?! Or if I’m stacking points in my Ulta Beauty Rewards Program to get this killer sampler pack, I don’t want to buy something off Google AI Mode that doesn’t ‘stack my points’ for me. I’m incented to leave and go to Ulta vs. the more streamlined Agentic checkout experience.

I predict mult-cart and loyalty are going to 100X the adoption of Agentic Commerce on both sides of the equation for Holiday ‘26 and then we’ll see what else the Naysayers come up with 🤣.

Saving the Best for Last: Merchant Center!👏👏👏👏

Back to Ashish:

At Google, we’ll continue to bring relevant UCP capabilities to shopping experiences in AI Mode in Search, the Gemini app and beyond. Additionally, we are actively working to onboard more retailers to agentic experiences on Google with a simplified UCP onboarding process in Google’s Merchant Center, rolling out over the coming months.

Both ChatGPT and Google appear to have announced and launched ACP/UCP and had more bespoke ‘design partner’ type integrations/launches. This is a great way to build, because you can get to a v2, v3 faster and learn while you’re launching - always the most agile and fast way to do things, especially in the AI Era where you are frequently ‘specing while building’.

The addition of a merchant center (also something we discovered ChatGPT is/was working on here waaay back in Feb!).

For this one, it’s all on the Google side and here’s a snippet of the landing page:

This landing page links to two things that merchants reading this will want to bookmark now:

1. Implementation guide/requirements here.

2. Sign-up page here.

Important Note: Don’t sign-up unless you are ready to 🚀! You’ll notice this very clear message in the form with an also clear warning:

Need help getting ready? Let us know, we are already rocking and rolling here at ReFiBuy HQ.

🔥Let’s GO!!! 🔥

See everyone next week at Shoptalk…

P.S. Your move Team ChatGPT….

P.P.S. This is also a significant up-grade to the types of things Amazon’s Shop Direct program can do, will they counter? 2026 is the best ecommerce timeline!