My ADAPTER makes an REST API call to get the initial snapShot for each subscription in command mode, so basically my table items are pulled via API call for the client.

I wanted to do the standard mechanism how can the client be notified for any Data retrieval Failure cases. So that the Client(UI) can pull the initial snapShot data by making external call via DB/API etc.

My concern is to create a FAST-FAIL notification mechanism to the client so the data can be pulled by some other mechanisms.

I am looking something like a kind of OPTIONS request in HTTP - method allows the client to determine the options and/or requirements associated with a resource, or the capabilities of a server, without implying a resource action or initiating a resource retrieval.