send
Reports the outcome of a device action to the server, which paused the task after sending it (see A2aEvent.DeviceActionEvent), and streams the events of the resumed task.
Allowed while the turn that delivered the action is still running or after it has ended. Collecting throws A2aSessionException with SessionError.Code.INVALID_INPUT when no action is awaiting a result, and with SessionError.Code.SESSION_CLOSED when the session is stopped.