🏦 Core Banking Service

A scalable and secure backend banking system built using Node.js, Express.js, MongoDB, and JWT Authentication.

This project simulates real-world banking operations including user authentication, account management, transactions, ledger tracking, and audit logging.

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📌 Features

🔐 Authentication & Authorization

• User Registration
• User Login
• JWT-based Authentication
• Protected Routes
• Token Blacklisting (Logout Support)

👤 Account Management

• Create Bank Accounts
• Account Validation
• Account Information Retrieval
• Customer Account Association

💸 Transaction Management

• Secure Fund Transfers
• Initial Account Funding
• Transaction Recording
• Transaction Validation
• Atomic Transaction Processing

📖 Ledger System

• Double-Entry Ledger Recording
• Financial Audit Trail
• Debit & Credit Tracking
• Transaction Ledger Management

📧 Notification Service

• Email Notifications
• Transaction Confirmation Emails
• Account Activity Alerts

🛡️ Security Features

• Password Hashing with bcrypt
• JWT Token Verification
• Protected API Endpoints
• Environment Variable Security
• Centralized Error Handling

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🏗️ Project Architecture

CORE-BANKING-SERVICE
│
├── src
│   ├── config
│   │   └── db.js
│   │
│   ├── controllers
│   │   ├── accountController.js
│   │   ├── auth.controller.js
│   │   └── transaction.controller.js
│   │
│   ├── middleware
│   │   └── auth.middleware.js
│   │
│   ├── models
│   │   ├── user.model.js
│   │   ├── account.model.js
│   │   ├── transaction.model.js
│   │   ├── ledger.model.js
│   │   └── blackList.model.js
│   │
│   ├── routes
│   │   ├── auth.routes.js
│   │   ├── account.routes.js
│   │   └── transaction.routes.js
│   │
│   ├── services
│   │   └── email.service.js
│   │
│   └── app.js
│
├── .env
├── server.js
├── package.json
└── README.md

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🛠️ Tech Stack

Technology	Purpose
Node.js	Runtime Environment
Express.js	Backend Framework
MongoDB	Database
Mongoose	ODM
JWT	Authentication
bcrypt.js	Password Hashing
Nodemailer	Email Service
dotenv	Environment Variables

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🚀 Installation

1. Clone Repository

git clone https://github.com/yourusername/core-banking-service.git

2. Navigate to Project

cd core-banking-service

3. Install Dependencies

npm install

4. Configure Environment Variables

Create a .env file:

PORT=5000

MONGO_URI=your_mongodb_connection_string

JWT_SECRET=your_secret_key

EMAIL_USER=your_email@gmail.com
EMAIL_PASS=your_email_password

5. Start Server

Development Mode

npm run dev

Production Mode

npm start

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📡 API Endpoints

Authentication

Method	Endpoint	Description
POST	/api/auth/register	Register User
POST	/api/auth/login	Login User
POST	/api/auth/logout	Logout User

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Accounts

Method	Endpoint	Description
POST	/api/accounts	Create Account
GET	/api/accounts/:id	Get Account
GET	/api/accounts/balance/:id	Check Balance

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Transactions

Transactions

Method	Endpoint	Description
POST	/api/transactions	Create Transaction
POST	/api/transactions/system/initial-funds	Create Initial Funds Transaction

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🔒 Security Features

• JWT Authentication
• Password Hashing using bcrypt
• Route Protection Middleware
• Environment Variable Security
• Token Blacklisting
• Input Validation
• Error Handling

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📊 Banking Workflow

User Login
     │
     ▼
JWT Generated
     │
     ▼
Authenticated Request
     │
     ▼
Transaction Processing
     │
     ▼
Ledger Entry Creation
     │
     ▼
Account Balance Update
     │
     ▼
Email Notification

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📈 Future Enhancements

• Role-Based Access Control (RBAC)
• KYC Verification
• Loan Management System
• Fixed Deposit Module
• UPI Integration
• Real-time Notifications
• Transaction Analytics Dashboard
• Microservices Architecture

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🧪 Testing

Run Tests:

npm test

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👨‍💻 Author

Riyanshu Sharma

B.Tech CSE (2024-2028)

Backend Developer | Banking Systems Enthusiast

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📄 License

This project is licensed under the MIT License.

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