FinTech App

Overview

The FinTech App is a full-stack financial application built using Node.js, Express, MySQL, and Sequelize ORM. It features secure user authentication and allows users to manage financial transactions like deposits and withdrawals.

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Table of Contents

• FinTech App
  • Overview
  • Table of Contents
  • Configuration Setup
    • Environment Variables
  • Authentication Logic
    • 1. User Model
    • 2. Routes for Authentication
    • 3. Route Guards
  • Database Schema
  • Running the Application
    • Prerequisites:
    • Steps:
  • Dependencies
  • Future Enhancements

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Configuration Setup

The project uses dotenv to manage environment variables. Make sure to set up a .env file at the root directory with the following configuration:

Environment Variables

DB_HOST=localhost            # MySQL Server Host
DB_PORT=3306                 # MySQL Port
DB_NAME=db                   # Database Name
DB_USER=root                 # MySQL Username
DB_PASSWORD=MySQL_Passwd     # MySQL Password
DB_DIALECT=mysql             # Database Dialect (Sequelize)
PORT=3000                    # Application Port
JWT_SECRET=super_secret      # JWT Secret for Token Generation
JWT_EXPIRES_IN=1h            # JWT Expiry Time

Replace placeholders like Password$123 and super_secret with your own secure values.

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Authentication Logic

The authentication system relies on:

1. Session Management using express-session
2. Password Hashing with bcryptjs
3. JWT Support for future extensions (optional)

1. User Model

Defined in user.js:

• Fields: id, email, username, password_hash, and balance
• Password Hashing: Passwords are hashed using bcryptjs before being stored.

Example Snippet:

import bcrypt from 'bcryptjs';

const passwordHash = await bcrypt.hash(password, 10); // Hash password

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2. Routes for Authentication

Routes are defined in auth.js:

• Login (/login): Allows users to authenticate with email and password.
• Register (/register): Enables new user registration.
• Logout (/logout): Clears user session.

Example Snippet:

router.post('/login', async (req, res) => {
  const { email, password } = req.body;
  // Check user credentials and start session
});

3. Route Guards

A middleware requireAuth ensures that only authenticated users can access secure pages like /dashboard and /transactions:

const requireAuth = (req, res, next) => {
  if (!req.session.user) {
    return res.redirect('/login');
  }
  next();
};

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Database Schema

The User and Transaction models are linked via foreignKey:

• User: Holds user information like email, password, and balance.
• Transaction: Tracks deposits and withdrawals.

Database tables:

CREATE TABLE user (
  id INT PRIMARY KEY AUTO_INCREMENT,
  email VARCHAR(255) UNIQUE NOT NULL,
  username VARCHAR(255) UNIQUE NOT NULL,
  password_hash VARCHAR(255) NOT NULL,
  balance DECIMAL(10, 2) DEFAULT 0.00
);

CREATE TABLE transaction (
  id INT PRIMARY KEY AUTO_INCREMENT,
  amount DECIMAL(10, 2) NOT NULL,
  type VARCHAR(255) NOT NULL,
  description VARCHAR(255),
  user_id INT,
  FOREIGN KEY (user_id) REFERENCES user(id)
);

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Running the Application

Prerequisites:

• Node.js installed
• MySQL server running

Steps:

1. Clone the repository.
2. Install dependencies:

   npm install

3. Setup .env as described.
4. Start the server:

   npm start

5. Access the app at http://localhost:3000.

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Dependencies

Key dependencies include:

• express: Web framework
• sequelize: ORM for MySQL
• bcryptjs: Password hashing
• express-session: Session management
• dotenv: Environment variable management.

Full list of dependencies can be found in the package.json file.

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Future Enhancements

• Add JWT-based authentication for API security.
• Enable deployment to cloud platforms like Heroku or AWS.
• Enhance UI with more dynamic components.