UCP employs a server-selects architecture where the business (server) chooses the protocol version and capabilities from the intersection of both parties' capabilities. Your UCP profile (known as business profile in UCP) will enable Google to efficiently negotiate capabilities with your server.
This profile is a JSON file that you host on your server at the well-known path:
/.well-known/ucp. It's crucial for integrating with Google, as it publicly
declares your server's capabilities and configurations for UCP.
What the UCP profile does
- Declares Capabilities: Informs Google which UCP features you support, such as different checkout processes, fulfillment options, discount applications, and order management.
- Specifies Versions: Locks down the specific versions of the UCP specifications and schemas you are using.
- Provides Endpoints: Tells Google where to send API requests for various services.
- Configures Payment Handling: Details how payment processing is set up, including parameters for payment methods like Google Pay.
- Shares Public Keys: Includes public keys used to verify messages sent from your server.
For more information about capability discovery, governance, and negotiation, see the UCP specification of business profile .
Google's UCP agent profile
Just as you host a business profile, Google hosts its own UCP agent profiles to publicly declare its supported capabilities, endpoints, and protocol versions. You can inspect these profiles during integration to verify if Google supports specific extensions, such as identity linking or buyer consent, for a given API version.
- Standard profile
- Version-specific
profile:
Change the date in the URL to view capabilities for other API versions, such
as
2026-01-23. - Minified profile
Next steps
View the UCP profile details for your UCP version: