How can a custom API be created in Salesforce Commerce Cloud?

Creating a custom API in Salesforce Commerce Cloud involves setting up a tailored controller that processes specific requests and defines corresponding behavior. This is effectively done through the creation of a custom controller and the configuration of routes in the routes.js file. The routes.js file serves as a mapping layer that connects HTTP requests to specific business logic implemented in the custom controller.

When a client sends a request to the Commerce Cloud application, the routes defined in routes.js direct that request to the appropriate handler in the custom controller. This process allows for a high degree of customization based on the specific needs of your application, enabling you to create tailored endpoints that align with your business functionality.

Using pre-defined APIs or purchasing services does not provide the same level of customization as creating a custom controller. Additionally, third-party APIs may be integrated but they do not substitute the need for a custom-built functionality tailored to specific requirements within the Salesforce Commerce Cloud environment. Thus, focusing on creating a custom controller with defined routes is the correct approach for establishing a custom API.