Authentication

While no authentication is required, Google supports the following options for use when calling the business's Native Checkout API and Cart API endpoints.

API keys

HTTP Header: X-API-Key

A shared secret value which will be used in Google's UCP API client request HTTP header to authenticate with the checkout endpoint.

HTTP Header: Authorization: Bearer <Access Token>

Following RFC 6749, Google's UCP Platform agent uses the following properties to request the access tokens needed for checkout endpoint interaction.

Property Description
Client ID A unique string representing the client (for example, Google's UCP API
client)
Client Secret A password type string used to authenticate with the authorization server
Authorization endpoint URL The URL to the OAuth2 API endpoint
Format Basic authentication HTTP header or HTTP body
Encoding Form data or JSON