Rest api state change after motion

Hello all,
we are sending a axis command/ kinematic command using the Rest API, it executes the command thats not the problem. The problem is that we dont know when this movement is done, unless we execute a get reqeust for a state change. Is there a better way then executing a get request every cycle using some sort of scheduler so the bus dousnt get overloaded with unnecessary reqeust ? We are open for suggestions if there is a better way to do this.