One-Time Scan QR Code Generator

A full-stack web application that generates QR codes for one-time use links. Once a link is scanned or visited, it expires and cannot be accessed again.

Features

• One-Time Use Links: Securely redirects users to a target URL only once.
• Auto-Expiry: Subsequent visits show a "Link Expired" message.
• Mobile Friendly: Automatically detects your computer's LAN IP so QR codes work on mobile devices connected to the same Wi-Fi.
• Clean UI: Responsive design for generating codes.

Prerequisites

• Node.js (installed on your machine)

Installation & Setup

1. Clone or Download this repository.
2. Navigate to the backend directory:

   cd backend

3. Install Dependencies:

   npm install

How to Run

1. Start the Backend Server: Inside the backend folder, run:

   node server.js

   You should see a message like: Server running on http://192.168.x.x:3000

2. Open the Frontend: Open the index.html file in the root directory using your web browser.

3. Generate a QR Code:

   • Enter a destination URL (e.g., https://www.google.com).
   • Click Generate QR Code.
   • Scan the QR code with your phone (ensure your phone is on the same Wi-Fi).

Project Structure

• /backend: Node.js/Express server that handles link generation and tracking.
  • server.js: Main server logic.
  • tokenStore: In-memory storage for tracking active links.
• index.html: Main user interface.
• QR-Code-Generator.js: Frontend logic to communicate with the backend.
• style.css: Application styling.

Troubleshooting

• "Failed to generate one-time link": Ensure the backend server is running (node server.js).
• Link not opening on phone: Make sure your phone and computer are on the same Wi-Fi network. The server attempts to automatically detect your local IP.