NFC Cards & QR Check-In

BizTech uses NFC membership cards and QR code scanning to streamline event check-ins and enable the Live Connection Wall. This page covers both systems end-to-end.

Overview

Here's how the systems work together at a BizTech event:

Attendee arrives → Admin opens the event dashboard and toggles the QR scanner
Admin scans QR code → The attendee's QR code (from their registration email) gets scanned
System checks in the user → Registration status is updated to "checked in"
NFC card check → The system checks if this person has a membership card
If no card → An NFC writing popup appears, and the admin taps a blank NFC card to the phone
Card is written → The NFC card now contains a URL that links to the user's profile
At the event → People tap each other's NFC cards to view profiles and create connections (which show up on the Live Wall)

QR Scan → Check In → NFC Card Check → Write Card (if needed) → Ready to Connect!

Key Files

Frontend

File	What it does
`src/components/QrScanner/QrScanner.tsx`	Main QR code scanner and check-in component
`src/components/QrScanner/types.ts`	TypeScript types for the QR scanner
`src/components/NFCWrite/NFCPopup.tsx`	NFC writing popup - shows user info and triggers writer
`src/components/NFCWrite/NFCWriter.tsx`	Handles the actual NFC tag writing via Web NFC API
`src/hooks/useNFCSupport.ts`	Hook to check if the device supports NFC
`src/hooks/useUserNeedsCard.ts`	Hook to check if a user needs a membership card
`src/util/nfcUtils.ts`	Utility to generate the NFC profile URL

Backend

File	What it does
`services/interactions/handler.js`	`POST /interactions` - creates connections when NFC cards are tapped
`services/interactions/helpers.js`	Connection logic and WebSocket broadcasting

What's Covered in This Section

QR Code Check-In

How QR codes work, the scanner component, validation flow, and check-in API.

NFC Card Writing

Web NFC API, URL format, writing flow, writer states, and support hooks.

Connections, Errors & Testing

How NFC creates connections, error handling, database records, and local testing.