Execution Listener Event Subscribing

I have an execution listener. Then event fires I catch it in execution listener, but when I try to fetch data requests returns no content. However, after instance created I can fetch data. Is it possible to implement event listener, which can help with sending real time notifications to users, for example, than new instance started or new task created or another event?

You can create a task listener that would be triggered for a number of events that occur in the life cycle of a user task. e.g.

I’m sorry to say i don’t really understand what you’re asking here. so maybe you could explain in more details and show some code to clarify.

I immediately send GET request with received task id from task event to process engine REST API and receive response what says no task with this task id.