Whether the event was a new call that was admitted.
OptionalBusySet when the call was refused only because the server is at its concurrent-call cap.
OptionalreasonWhy it was not (no agent for the number, at capacity, not a phone call, a repeat).
OptionalStartedResolves when the agent's session has started (or failed and been cleaned up). Never rejects. Callers ignore it; tests await it.
The outcome of an inbound call webhook.