Like you want to have a dumb lock but a smart sensor that tells you if the deadbolt is locked or open?
I remember reading some blog somewhere about a person who rigged up a sensor to alert them if their mailbox had been opened or not, you could probably design something to do similar. Idk maybe a magnetic thing to detect the bolt itself, or something to detect on the position of the latch on the interior of the door?
Found this after a quick search, sorry for it being Reddit and the video of the working solution being uploaded to gfycat.