Scanner setup

Turn any phone or laptop with a camera into a gate scanner. No app install — it runs in the browser.

1. Create a scanner account

In Settings → Scanners, add a scanner for each gate (e.g. “North 4”, “VIP”). Each gets a short access code so volunteers can sign in on a shared device without your dashboard credentials.

2. Open the scanner

Go to Dashboard → Scan, choose the event and gate, and grant camera permission. The scanner uses html5-qrcode to read tickets continuously.

3. Scan

Each scan returns one of five verdicts:

• VALID — first valid scan; the ticket is checked in.
• ALREADY_USED — the ticket was already checked in.
• WRONG_EVENT — a ticket for a different event/org.
• EXPIRED — the signed token is past its expiry.
• INVALID — bad signature or cancelled ticket.

Why duplicates are impossible

Check-in is a single atomic database update that flips the ticket from VALID to USED only if it is still VALID. If two devices scan the same code at once, exactly one wins; the other gets ALREADY_USED.

// atomic compare-and-set
const updated = await prisma.ticket.updateMany({
  where: { id: ticketId, status: "VALID" },
  data:  { status: "USED", checkedInAt: new Date() },
});
// updated.count === 1  -> this device checked them in
// updated.count === 0  -> someone already did