Hi,
When doing automations in NodeRED (similar to the internal HA automations) it is possible to issue service calls to get HA to change entity states etc. Unfortunately there is no feedback on that service call. So after making the service call, it is not possible to check if the call has been properly processed.
However, this is not only the case with NodeRED. Even when calling a service in Developer Tools there is no feedback on the success of the call, other than human interaction to see if the requested action actually worked. The same applies to API calls, which do give you feedback but only tell you if the web call itself was successful but provides no information about the status of the actual service call.
This is properly documented with just about every Home Assistant video released (even those by Nabu Casa themselves), as a device is always used (usually lights) to show HA has taken action, instead of there being some programmatic (JSON) response.
In many cases this is not necessary as (NodeRED and internal) automation has been working fine without this. However, giving feedback is simply good development, and in some cases you would definitely want to know (and be able to check in an automation) if a service call has resulted in an error or not.
For example when arming (or disarming) the alarm, where you may want to take additional action on a failed call. Or when processing a conversation where you would want feedback on what HA has done or not.
And with conversation.process we have the one notable exception (afa i can see in the docs @ Conversation API | Home Assistant Developer Docs). With a conversation.process call an API call does result in feedback on successes, fails and errors. So HA is technically capable of gving service call feedback, it’s just not showing it in DevTools\Services and NodeRED calls.
I would propose a change to HA to be able to give feedback (in automations, DevTools and also NodeRED) when making a service call.
For automations (and in NodeRED) i would propose an optional checkmark with the service call (node) to tell the automation to wait for a response.