A scanner, not an app

A phone with a camera and a browser. That is the entire requirement, for you and for every volunteer you hand the door to. There is nothing to install, nothing to log a volunteer into beyond your own organizer session, and nothing that stops working because someone did not update it.

1. 1.Open the scanner page for your event and allow camera access.
2. 2.The player shows their pass on their phone.
3. 3.Point, scan, and the result comes back from our server — confirmed, already checked in, wrong event, or not valid.
4. 4.Carry on. The participant list updates as you go, so you always know who has actually arrived.

There is a manual check-in too, for the phone that has died in the queue.

The scanner does not decide anything. It reads a pass and asks; our server answers. A pass for a different event fails. An already-used or rotated pass fails. A participation that is not confirmed fails. None of those checks can be bypassed by faking what the scanner shows, because what the scanner shows is the answer, not the decision.

It matters more online than most organizers expect. A check-in window before start tells you who has actually turned up while you can still promote from the waitlist — which is the difference between a full lobby and four empty slots at match one.

• Camera access requires HTTPS. On the live site that is automatic; on a local dev server it is not.
• The scanner is loaded on demand rather than bundled into the app, so it costs nothing for the visitors who never check anyone in.
• Two people scanning at once is fine — validation is server-side, so there is no local state to conflict.
• It is a check-in tool, not identity verification. It confirms a valid pass for this event, not who is holding it.