Google Boosts UCP with Cart Features

Google has rolled out a major update to its Universal Commerce Protocol (UCP), introducing new Cart and Catalog capabilities, highlighting Identity Linking, and simplifying the onboarding process for retailers through Merchant Center. These changes aim to make AI-driven shopping experiences more complete and accessible for businesses of all sizes.

New Cart Functionality

One of the key updates is the introduction of the Cart feature. This allows AI agents to manage multi-item shopping baskets from a single retailer, enabling customers to explore products and add them to a basket before committing to checkout. Previously, UCP primarily supported single-item transactions, but the addition of Cart now lets AI agents replicate a full shopping experience, closer to traditional e-commerce.

Cart is designed for pre-purchase exploration. Shoppers can build a basket over time, and when they are ready, the AI agent can convert the basket into a checkout session. This flexibility is expected to make UCP-powered shopping more seamless and user-friendly, particularly for larger purchases or multi-item orders.

Real-Time Product Details with Catalog

Alongside Cart, Google has introduced the Catalog capability. This allows AI agents to pull live product data from a retailer’s inventory, including pricing, stock levels, and product variants. Previously, agents relied on static product feeds, but Catalog enables real-time queries, improving accuracy and making product discovery easier for users.

Retailers can now ensure that shoppers receive up-to-date information on availability and options, whether they are browsing multiple items or conducting targeted searches. Catalog supports both general search and direct product lookups, helping AI agents guide shoppers more effectively.

Identity Linking Enhances Loyalty Integration

Identity Linking, already part of UCP’s stable specification, is now highlighted as a key option for retailers. This feature allows shoppers to connect their retailer accounts across UCP-integrated platforms using OAuth 2.0.

With Identity Linking, loyalty pricing, member discounts, and free shipping offers can carry over even when purchases are made via AI interfaces like Google’s AI Mode or the Gemini app, rather than directly on the retailer’s website. This makes the transition to AI-powered shopping smoother for customers while maintaining loyalty benefits.

Optional Features for Retailers

All three features—Cart, Catalog, and Identity Linking—are optional, giving retailers the flexibility to choose which capabilities to support based on their business needs. Google’s approach ensures that smaller businesses or those with simpler operations can adopt UCP without being forced into complex integrations.

Simplified Merchant Center Onboarding

In addition to new features, Google has simplified the UCP onboarding process through Merchant Center. The goal is to encourage wider adoption, particularly among retailers without dedicated engineering teams.

Currently, only listings using the native_commerce product attribute display the checkout button. Selected merchants can apply for early access via an interest form. The company plans to roll out the updated onboarding process over the coming months.

Support from Platform Partners

Several major platform partners have already announced plans to implement UCP. Commerce Inc, Salesforce, and Stripe each confirmed upcoming integrations, which could lower the technical barrier for retailers who are not building direct UCP connections.

These partnerships make it easier for businesses of all sizes to participate in AI-powered shopping experiences without needing extensive in-house technical expertise.

Why This Update Matters

The addition of Cart and Catalog fundamentally expands UCP’s functionality. Retailers can now offer multi-item shopping baskets and real-time product information, making AI-powered purchases more comparable to traditional e-commerce. Meanwhile, Identity Linking allows loyalty benefits to remain consistent across platforms, helping retailers retain their customer engagement.

However, there are trade-offs. Sales processed through UCP occur on Google’s surfaces rather than directly on retailer websites. While this could appeal to some retailers due to the broader reach and AI-assisted shopping experience, others may view it as a potential loss of control over customer interactions and loyalty programmes.

Looking Ahead

Cart and Catalog are currently draft specifications and may evolve based on community feedback. Google has indicated plans to expand UCP capabilities across AI Mode in Search, the Gemini app, and potentially other platforms in the future.

For retailers, these updates present both an opportunity and a challenge: adopting UCP can improve shopping experiences and simplify integration, but careful consideration is needed regarding how AI-managed purchases affect brand control and customer relationships.

In summary, Google’s latest UCP updates mark a significant step forward in AI-assisted e-commerce. By introducing Cart, Catalog, and Identity Linking, along with simpler onboarding, UCP is moving closer to replicating a full shopping experience for users while lowering barriers for retailers. Businesses that embrace these features early may gain an advantage in the rapidly evolving AI-driven commerce landscape.