You can call an API with any application to which a user has access, instead of with only the default application. This enhancement makes it easy to switch between applications in the React UI, and to make API calls within your Pega application.
When you specify the application name in your application alias URL, at run time, the REST service chooses the access group in the operator record that most closely corresponds with that application. Additionally, you can develop REST services without changing the access group in the service package.
The following figure shows the application alias URLs available for each application to which an operator has access.
For more information, see Invoking a REST service rule.