A safety gate for preventing pets and small children from passing through an opening, the safety gate comprising: a frame for selective disposition in the opening, the frame defining a passageway； a cross-member for adjustable mounting to the frame so as to prevent a pet or small child from passing through the passageway； a sensor mounted to the frame for sensing data relating to the state of the safety gate； and a wireless communication system for transmitting data from the sensor to a smart device.
