hah I did something similar at a small startup working out of a big live/work loft when they ran out of key fobs to give us. You'd buzz our unit which would cal

hah I did something similar at a small startup working out of a big live/work loft when they ran out of key fobs to give us. You'd buzz our unit which would call a Twilio number which sent a message to the super secure "front door" slack room saying "someone is at the door. let them in?" and you'd open slack on your phone and hit the button to let yourself in. Very secure stuff.