There are certain APIs for which SCS does not require interaction with the devices it-self. All those operations will be synchronous i.e. SCS will not respond with a correlation Id but returns immediately the final result. Some examples include:
- Application Registration
- Delete Subscriptions to resources and lifecycle events
- Read all Subscriptions to resources and lifecycle events
- Read single Subscription to resources and lifecycle events
- Add devices
- Delete devices
- Get devices
There is another set of APIs as well which require interaction with the devices. All those operations will be asynchronous. For such APIs, device's responses arrive in the notification channel which you can establish by registering an application URL. An HTTP request will return immediately with a correlation Id (subscription Id for observing resources, Request Id for a single operation on a single resource). Some examples include:
- Read, Write, Delete, Execute Resource on the devices (e.g. send downlink message)
- Subscription to Resources / Life Cycle Events
- Further sections of this document will explain more about these APIs.