Hello support, could you please help with this question?

is there a way to receive an event timestamp using DMCC API?

Or, is there a unique event ID/sequence number?

Or, if we have two arbitrary event payloads, is there a way to detect if they represent the same event?

given your last statement, not really. A call has a universal Call identifier (UCID). If the same call appears at two different devices (or event streams) you can be sure the events are for the same call. But that doesnt extend to any random event. There is no timestamp provided by CM for events, nor sequence number associated with an event. SequenceIds are unique to a session, and have no relationship across two sessions to each other.

Got it..
Thank you.

I'll add that calls have callIDs and in general the data in the events related to a callID will also line up if the callIDs line up. The events coming from a common AES should be in the same sequence and contain the same data, but there is no guarentee of that in the protocol specification. There is also no stated guarentee that call events will appear in the same order in two different event streams. When you start considering separate event streams coming from separate AESs, all you can be sure of is that the CallIDs and UCIDs will match up.