Event Check-In

How attendees get checked in at events, what happens in the backend, and the admin tools involved.

Check-In Methods

There are two ways to check someone in:

QR Code Scan

Each registered attendee receives a QR code in their confirmation email. At the event, an admin scans this QR using the scanner at /admin/event/[eventId]/[year] (the QR Scanner tab in the event dashboard).

The QR code encodes the attendee's email and event identifiers. When scanned, the frontend calls:

PUT /registrations/{email}/{fname}
{
  "eventID": "blueprint",
  "year": 2026,
  "registrationStatus": "checkedIn",
  "isPartner": false
}

Manual Check-In

Admins can also click on an attendee row in the Data Table tab of the event dashboard and change their status to "checkedIn" directly. This calls the same PUT endpoint.

Backend: updateRegistration()

Handler: services/registrations/handler.js → updateRegistration

When a check-in request arrives:

1. Receives { eventID, year, registrationStatus, ...otherFields } in the body
2. Email comes from the path parameter
3. Calls updateHelper() with the update payload

The updateHelper() Function

This is the core registration update function used by check-in, registration, and mass-update operations.

For a check-in specifically, updateHelper():

1. Queries the event from biztechEvents to get capacity (capac) and event details
2. Counts current registrations via GSI event-query
3. Skips email sending for checkedIn status (emails are only sent for registered and waitlist statuses)
4. Writes the status update to biztechRegistrations using db.updateDB()

The capacity check still runs during check-in even though it's not relevant — the function is shared across all registration status changes.

Registration Status Values

Check-in changes the status from registered (or accepted/acceptedComplete) to checkedIn.

What Happens After Check-In

Once checked in, the attendee can:

1. Access the Companion App — at /companion/{eventId}/{year}, which shows their profile, quests, and connections
2. Use NFC tapping — if the event has NFC cards, tapping another attendee's card triggers a connection via the interactions service
3. Complete quests — gamified tasks tracked in biztechQuests

QR Code Generation

The QR code is generated and emailed during the initial registration, not at check-in. The flow:

1. User registers → POST /registrations/ or PUT /registrations/{email}/{fname}
2. updateHelper() calls SESEmailService.sendDynamicQR() which generates an inline QR code image
3. The same email also includes a .ics calendar invite attachment via sendCalendarInvite()

QR emails are not sent for these statuses: incomplete, rejected, accepted, checkedIn, or partner registrations (isPartner: true).

Admin Dashboard: Event Day View

The admin event dashboard at /admin/event/[eventId]/[year] has several tabs relevant to check-in:

The Data Table updates in real time as attendees are checked in, showing the current count of checked-in vs registered attendees.

Key Files

Related Pages

• Registration System — full registration lifecycle
• Event Lifecycle — where check-in fits in the broader event flow
• QR Code Check-In — deeper QR implementation details
• Companion System — what attendees use after check-in