Is there any way i can use a Binary Sensor as a callback constraint? Cant find any documentation on it
there is no callback constraint for that, but there is a good chance that if you use the input_boolean constraint and give a binary sensor that it would work also, because its also on/off.
if it doesnt work you could use:
if self.get_state(self.args["binary_sensor"]) == "on":
at the start from your callback