These APIs let you create and update Checkout applications without manual configuration in the Merchant Center, providing a fast, scalable, and consistent way to manage your checkout and payment experience. You can automate updates, maintain consistent Checkout settings across multiple Stores or Regions, and roll out changes while saving time and reducing manual work. The APIs are designed to be used together when creating a new application:

• The Checkout Applications API defines the application itself.
• The Checkout Payment Integrations API configures the payment methods.

For updates, each API can be used independently. This allows you to modify only what you need. Both Complete Checkout and Payment Only applications are supported.