Frequently Asked Questions

Find answers to common questions about the Universal Commerce Protocol (UCP).

General

What is the Universal Commerce Protocol (UCP)?

UCP is our new open standard designed to unify digital commerce. We built it to enable direct, instant purchases across AI surfaces like AI Mode in Search and the Gemini app. Our goal is to reduce friction in the buying process and help you minimize cart abandonment.

What are the main benefits of integrating with UCP?

When you integrate with UCP, you gain:

  • Expanded reach: access to users directly on our surfaces, including AI Mode in Search and the Gemini app.
  • Reduced checkout friction: we enable direct purchases within the interaction flow, keeping users engaged.
  • Control: you remain the Merchant of Record, maintaining full control over your customer relationships and data.
  • Flexibility: we offer different integration paths (Native and Embedded) to suit your brand and technical stack.
  • Readiness for agentic experiences: we are designing this to support upcoming agentic capabilities, such as multi-item carts and account linking.

What makes UCP different?

  • Modular and extensible: UCP is designed to be modular and extensible to support rich commerce experiences using capabilities and extensions.
  • Fast and easy to implement: UCP allows merchants the choice to select the set of capabilities & extensions they want to support and the communication medium that best suits their development needs such as APIs, MCP or A2A.
  • Co-designed with industry leaders: UCP is open source and is designed directly by a collaboration of industry leaders, to support the diverse needs of a rich commerce ecosystem.
  • Secure and seamless payments: UCP supports secure payments using tokenization and allows merchants to build on existing payment integrations using payment handlers.

What surfaces will our integrations appear on?

At launch, your UCP integration will power experiences on AI Mode in Search and the Gemini web application. We are planning support for the Gemini app and other surfaces in the future.

Integration & Technical

Is UCP compatible with my existing tech stack?

We built UCP on open standards, making it seamlessly compatible with major existing protocols you might already use, such as AP2, A2A, and MCP.

Do I need to make changes to my Merchant Center account?

Merchant Center remains central to our ecosystem. You must ensure your product feeds, brand assets, return policies, and business contact information are complete and up-to-date there. We provide specific data requirements in our Implementation Guides.

How are we different from other protocols?

We designed UCP as a comprehensive open standard specifically for AI-driven commerce, co-developed with industry partners. Unlike protocols focused solely on payments, we support the broader shopping journey (including discovery and consideration) powered by our Shopping Graph.

How does UCP relate to the Agent Payments Protocol (AP2)?

AP2 is our standard for secure, agent-led payment transactions. We use UCP to orchestrate the broader purchase lifecycle, while AP2 can be used as a specialized payment layer within UCP. This is particularly useful for future scenarios involving autonomous AI agent transactions.

What is the difference between our Native and Embedded integration paths?

  • Native Integration: you provide a deeper API integration, allowing us to handle the checkout logic directly within the AI surface. We recommend this path to unlock the full potential of future agentic use cases, multi-item carts, and personalization.
  • Embedded Integration: we route the user to a checkout UX that you control, embedded within our surface. This is available if you have specific checkout elements that our Native integration doesn't support.

How do we process payments? Do I need to support Google Pay?

Our payment flow is similar to the Google Pay API's facilitated payment. We securely pass encrypted payment details to your Payment Service Provider (PSP). You don't need a Google Pay button on your website to use UCP, but your PSP must be able to process our tokens. Most major global PSPs already support this.

If I already have Google Pay, will you respect my existing configuration (e.g., card restrictions)?

Because UCP is a new integration, we require you to provide configuration specifically for this channel. You will need to define your parameters (such as restricting AMEX) specifically for your UCP integration.

How do I distinguish traffic from UCP verse my own channels?

We exchange checkout, order, and transaction lifecycle events using the API contracts established in our specifications. This lets you clearly differentiate traffic and payments flowing through our AI surfaces versus your own website or app.

How do we handle real-time inventory checks?

Before we enable the final "Buy" button, we perform a real-time inventory check against your API. If an item goes out of stock during the transaction, our standard error handling applies, and we inform the user immediately.

User Experience

Will Native integration affect my product ranking?

No. Opting for our Native integration does not influence how we rank your offers in product listings. The user experience for listings remains consistent; however, offers integrated with UCP will feature the direct purchase option.

Can users change their shipping address during checkout?

Yes. We allow users to review and change their shipping address during the flow. We expect your system to dynamically update shipping costs and taxes based on the new address provided.

Will I lose control of my customer data?

No. You are the Merchant of Record. You retain full ownership of your customer relationships and data.

How do we handle customer privacy?

Our standard security and privacy practices apply to the interaction, but you own the transaction data. We are also building features like account linking that are designed to keep the user in control of their data.

What Terms & Conditions apply to a UCP transaction?

Your Terms & Conditions cover the purchase, just as if the customer checked out on your own website. We display these terms to the customer, and they must accept them during the checkout flow.

Are there limitations on re-marketing to customers acquired through UCP?

Since you are the Merchant of Record, you possess the customer's information just as you would for a direct purchase. Standard privacy regulations and consent practices apply. We are planning a feature that will allow users to explicitly opt-in to marketing communications during checkout in a future update.