5 Work With Services
Many of the UI components in your App UI are bound to data that comes from REST APIs, which in turn are provided by services, like Oracle Cloud Applications. These services are made available to your extension through backends and service connections.
A backend is a representation of an external system whose data you wish to consume. A service connection provides basic information about a service, including the REST endpoints and schema provided by the service, in an Open API-compliant format.
Service connections are defined at the extension level, which means that all the App UIs in your extension can use them. In addition, you can use service connections provided through a dependent extension as a source of data for other App UIs in your extension, whether you're creating the App UI from scratch or configuring an existing App UI.
Backends help you manage the servers on which the REST APIs are hosted. By gathering server details together in one place, backends make it easier to create service connections, as well as to manage the server details themselves. The Unified Application provides a backend called "Oracle Cloud Applications for all services", which points to the servers hosting the Application Core API, the Sales and Services API, and more:
While you can't modify the service connections or backends that come from dependent extensions (including the Unified Application), you can create your own and reuse them across all the App UIs in your extension.
Important: When creating your own service connection or backend, you must mark it as "Accessible to application extensions" if you want to allow their use by dependent extensions.