About this project

The Paytm Clone is a full-stack fintech application that simulates the complete payment transaction lifecycle — from order creation to payment gateway redirect, callback handling, and transaction status verification. Built with Next.js, it replicates real-world payment flows used by Paytm and similar UPI-based platforms: the frontend initiates a payment order, receives a payment token, redirects the user to a mock payment page, and handles the async webhook callback to update order status. The system implements idempotency keys to prevent duplicate transactions, secure HMAC-based webhook signature verification, and a clean transaction dashboard. This project demonstrates practical understanding of payment gateway integration patterns, webhook security, and fintech application architecture — skills directly applicable to real-world payment system development.

Key highlights

• End-to-end payment lifecycle: order creation, redirect, callback, verification
• HMAC webhook signature verification for secure payment callbacks
• Idempotency keys to prevent duplicate transaction processing
• Mock payment gateway with realistic redirect and return flows
• Transaction history dashboard with status tracking
• Next.js App Router with server actions for secure API calls
• Clean fintech UI with Tailwind CSS and React
• Demonstrates UPI/Paytm integration patterns for real-world use