Where I live, the smart locks I saw are mounted in from the inside and go over the existing screw bolt thing that unlocks the door. From outside you would have

Where I live, the smart locks I saw are mounted in from the inside and go over the existing screw bolt thing that unlocks the door. From outside you would have no idea that it's a smart lock. But yeah, they don't have something outside you could touch an NFC tag on to unlock