You walk in.
Letters Books on a Thursday. You pull out your phone, open Kythen, tap the name of the place. The orb warms, holds a beat, and settles. You're kythening at Letters Books.
That is the whole ceremony. Nothing asked, nothing announced. The venue knows a guest has arrived on the platform. The app knows you are here. Nobody else has been notified, nobody is yet visible to you. Just a quiet confirmation that you have crossed the threshold.