Realtime API: is it possible to track with event triggered a response?

I don’t think the Realtime API currently exposes a direct “triggering client event ID” field on server events.

response.create can include an optional client-side event_id, but the later response.created event has its own server-side event_id and the new response.id. It does not appear to echo the original response.create.event_id.

For debugging, the best workaround is to include your own correlation ID in response.metadata:

{
  "type": "response.create",
  "event_id": "client_event_123",
  "response": {
    "metadata": {
      "client_event_id": "client_event_123",
      "debug_reason": "manual_retry"
    }
  }
}

Then inspect response.metadata on response.created or response.done and map it to the returned response.id.

One related detail: only one Response can write to the default Conversation at a time, but out-of-band responses can run in parallel. The docs specifically call out metadata as a useful way to disambiguate simultaneous Responses.