When a guest RSVPs, their private link turns into a QR pass. It carries a signed token — no personal data is stored in the code itself — and it works offline once loaded, so a spotty venue signal won't lock a guest out.
Open the check-in desk (in the app, or on the web as a backup), point the camera at the guest's QR, and their name, party and seating appear instantly. Tap to check them in. You can also type the code by hand if a camera isn't available.