💳 PayCore (Razorpay API, ShadCN, React, Node.js, MongoDB)

PayCore is a modern, full-stack fintech application that allows users to send and receive money instantly. It is designed with a minimalist Swiss Design philosophy, real-time payment integration, and bank-grade security practices.

Click here to try the Live Demo

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✨ Features

• Add Funds (Razorpay): Securely add funds using Razorpay (Cards, NetBanking, UPI – test mode)
• P2P Transfers: Instantly send money to other users using name or username
• ACID Transactions: MongoDB sessions ensure atomic money transfers (no partial failures)
• Idempotent APIs: Prevents duplicate or double-spend transactions during retries or network failures.
• Transaction History: Ledger-style history with incoming/outgoing transactions
• Optimized User Search: Debounced search to reduce DB load
• Secure Authentication: JWT-based auth with Zod validation & Bcrypt hashing
• API Rate Limiting: Implemented Express middleware–based rate limiting to prevent brute-force attacks and ensure service availability
• Modern UI: Tailwind CSS + ShadCN/UI
• Smart Notifications: Real-time toast alerts using sonner

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HLD

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🛠️ Tech Stack

Layer	Technologies
Client	React + Vite, TailwindCSS, ShadCN/UI, Axios, Lucide Icons
Server	Node.js, Express.js, Razorpay SDK
Database	MongoDB (Mongoose ORM)
Security	JWT, Bcrypt, Zod, HMAC Verification, Idempotency Keys, CORS, API Rate Limiting (Express Middleware)

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🧩 API Modules Overview

This project exposes REST APIs grouped into User & Auth, Accounts, and Payments (Razorpay).

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👤 User & Auth APIs

Method	Endpoint	Description
POST	/api/v1/users/signup	Register a new user
POST	/api/v1/users/login	Login and receive JWT
GET	/api/v1/users/bulk	Search users (supports ?filter=name)

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🏦 Accounts APIs

Method	Endpoint	Description
GET	/api/v1/account/balance	Get current balance & user details
POST	/api/v1/account/transfer	Transfer money to another user (ACID)
GET	/api/v1/account/history	Fetch last 10 transactions

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💸 Payments (Razorpay) APIs

Method	Endpoint	Description
POST	/api/v1/payment/create-order	Initialize Razorpay order
POST	/api/v1/payment/verify	Verify payment & credit balance

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❤️ Health Check

GET /api/v1/healthcheck

Used to verify server availability.

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🔐 Authentication Details

• JWT token generated on signup/login
• Token must be sent via header:

Authorization: Bearer <token>

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📌 API Reference (Detailed)

Signup

POST /api/v1/users/signup

Field	Type	Required
username	string	✅
email	string	✅
password	string	✅
fullname	string	✅

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Login

POST /api/v1/users/login

Field	Type	Required
username	string	✅
password	string	✅

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Transfer Money

POST /api/v1/account/transfer

Field	Type	Description
amount	number	Amount to send
to	string	Receiver userId
Authorization	Bearer token	JWT token

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Update User Details

POST /api/v1/users/updateDetails

Field	Type	Notes
password	string	Optional
fullname	string	Optional

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Get Balance

GET /api/v1/account/balance

Returns logged-in user's balance.

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Search Users

GET /api/v1/users/bulk

Supports debounced search using query params.

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⚙️ Installation Guide

Server Setup

npm install
# configure MONGO_URI, Redis_URL in .env
npm run dev

Client Setup

npm install
npm run dev

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📦 Libraries Used

Server Side

• Zod – input validation
• JWT – authentication
• Bcrypt – password hashing
• Mongoose – MongoDB ORM

Client Side

• React Router DOM
• Axios
• Dotenv

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📘 Notes

• Razorpay runs in test mode
• MongoDB transactions ensure zero money loss
• Designed with scalability and production-readiness in mind

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🚀 PayCore – A clean, secure, production-grade fintech system.