How to start UCP integration in Merchant Center

The UCP integration page in Merchant Center guides you through testing and validating your UCP implementation.

Customized validation paths

Merchant Center offers customized validation paths based on your chosen UCP capabilities. Integration steps and requirements adjust to your selection:

• "I support transfer to merchant cart": experience a fast-track validation path to enable shoppers to transfer items to your site to finish checkout. This streamlined path doesn't require full product feed setup, product warnings, or customer support information.
• "I support native checkout on Google": follow a streamlined validation checklist to enable shoppers to buy directly on Google. This path focuses on implementing checkout API endpoints.
• "I support identity linking": enable loyalty benefits and authenticated checkouts by implementing your OAuth 2.0 endpoints and publishing your metadata for identity linking.

The integration process consists of three main stages:

1. Implement UCP by following the guide instructions: understand the core UCP concepts and technical requirements.
2. Test your UCP implementation in a sandbox environment: safely test and debug your integration.
3. Onboard to UCP and validate your capabilities in production: select your capabilities, publish your profile, and confirm your integration works correctly in a production environment.

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Access the UCP integration tab

During this early access phase in the US, you can find a dedicated UCP integration tab in the navigation menu.

1. In your Google Merchant Center account, click Settings in the navigation menu.
2. Select UCP integration.

The page is divided into two tabs:

• Overview: opens by default and guides you through technical setup, sandbox testing, and production validation.
• Analytics: gain visibility into your UCP checkout funnel across agentic buy flows and track key performance metrics.

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Implement UCP with developer guide

Review the UCP implementation guide to understand the integration steps. This guide covers the core API specifications and concepts.

Test your UCP implementation in a sandbox environment

Click Test on the Test your UCP implementation in a sandbox environment card to access the "UCP sandbox integration" page. This lets you safely test your integration across various use cases and review your server's responses.

Set up Checkout API keys

To allow Google call your APIs for testing and production, provide API keys from your system. These keys authenticate requests from Google to your endpoints.

• Requirements: Google encrypts and stores your domains and associated API keys. Generate dedicated keys for this integration.
• Environments: provide separate API keys for your staging (sandbox) and production environments.
• Submission: contact us by email to discuss supported methods and exchange keys. Find our contact email by navigating to Settings > UCP integration.

Provide your UCP profile location and credentials

To test your UCP integration in the sandbox environment, provide the following information:

• UCP profile location: provide the path to the /.well-known/ucp file you want to test. This URL lets Google discover your server's capabilities and API endpoints.
• API key: enter the API key if your test environment requires it for authenticating requests.
• Override access_token: optionally, provide a specific OAuth Bearer token here to use for API requests.

Simulate cart transfer actions

If you're implementing the Cart Transfer capability, expand the Cart transfer / API section to simulate requests and ensure your system correctly handles carts:

• Create Cart: tests the initialization of a new cart session when a user transfers items from Google to your site.
• Get Cart: (Optional) tests retrieving the current state of an active cart session.
• Update Cart: (Optional) tests handling updates to an existing cart (for example, modifying line item quantities).
• Cancel Cart: (Optional) tests the termination or abandonment of a cart session.

Simulate native checkout actions

If you're implementing Native Checkout, expand the Native checkout section to simulate the core purchasing flow:

• Create checkout: tests initiating a new checkout process. Enter the request details in the provided JSON editor and click Test.
• Update checkout: tests how your integration handles updates to an existing checkout (for example, a user updates the shipping information).
• Complete checkout: simulates the final purchase step to verify successful transaction completion.

Validate your UCP capabilities in production to go live

Select Select Start on the Validate your UCP capabilities in production to go live card to start the production validation process. This validation flow guides you through selecting capabilities, publishing your profile, and verifying your integration.

Step 1: Select UCP capabilities

Select the UCP features you want activated for your integration. A preview of the consumer experience will show on the right-hand side.

• Transfer to merchant cart: enable shoppers to add products to a cart on Google, then seamlessly transfer items to your site to finish checkout by implementing the Cart API.
• Native checkout on Google: enable shoppers to buy directly on Google by implementing 3 core REST endpoints for session creation, updates, and completion.
• Identity linking: enable loyalty benefits and authenticated checkouts by implementing OAuth 2.0.

Note: the Identity linking capability becomes available for selection only if you select the Native checkout on Google option.

Step 2: Publish UCP profile

Provide your UCP profile location. Based on this location, Google will check the capabilities you've chosen to support. Ensure that the capabilities declared in your UCP profile exactly match the capabilities you selected in Step 1 (e.g., if you selected identity linking, it must be present in your profile).

• Enter your UCP profile location URL (for example, https://example.com/.well-known/ucp).
• Click Add. Google will check your profile and display the discovered capabilities.
• Learn more about the Merchant UCP Profile.

Step 3: Validate UCP implementation

Depending on your selected capabilities, a detailed checklist will be displayed to continue the validation process. Complete the checklist that applies to your integration path:

Note: You can choose to implement Native Checkout, Transfer to merchant cart, or both. If you choose both, you must complete the checklist items for both capabilities.

Transfer to merchant cart capability only

If you are only implementing cart transfer, you will see a streamlined checklist:

• Configure Merchant Center account for UCP: ensures the matching product ID configuration is complete.
• Validate cart transfer: run tests to ensure your Cart API is implemented correctly.

Native checkout on Google capability

If your integration includes native checkout, your checklist includes the following steps.

Note: If you took the opportunity to enable identity linking when selecting this capability, you will also validate your OAuth 2.0 flow here.

• Configure Merchant Center account for UCP: ensures all configurations are complete.
• Validate identity linking (optional): if enabled, implement your OAuth 2.0 endpoints and publish your metadata.
• Validate native checkout integration: implement and validate the 3 core REST endpoints. You can see a preview of the native checkout paysheet; by selecting Pay with GPay, you can begin the validation process.
• Validate order status: configure webhooks to send order updates to Google.
• Review and agree to the UCP Program Addendum.

After completing all validation steps, the Google Support team reviews your UCP integration. You are notified whether your account is live or if any setup issues need to be addressed.