Authentication System For Mutual Funds Loan Application

A full-stack authentication system built with NestJS (backend) and Next.js (frontend) featuring JWT authentication, session management, and multi-device support.

🚀 Tech Stack

Backend:

• NestJS 11
• PostgreSQL
• TypeORM
• JWT Authentication
• bcryptjs
• Swagger API Documentation

Frontend:

• Next.js 15
• React 19
• TanStack Query
• Shadcn UI
• Tailwind CSS
• Zod Validation

✨ Features

• ✅ User Registration & Login
• ✅ JWT Access & Refresh Tokens
• ✅ HttpOnly Cookie-based Authentication
• ✅ Multi-device Session Management (Max 3 devices)
• ✅ Token Blacklisting
• ✅ Account Lockout (5 failed attempts, 15 min duration)
• ✅ Device Tracking (IP, User-Agent, Platform)
• ✅ Session Revocation (single & all devices)
• ✅ Automatic Session Cleanup (Cron Jobs)
• ✅ Environment Validation
• ✅ Full TypeScript Support
• ✅ Swagger API Documentation

📋 Prerequisites

• Node.js 20+
• PostgreSQL 14+
• pnpm (recommended) or npm

🛠️ Backend Setup

1. Navigate to backend directory

cd backend

2. Install dependencies

pnpm install

3. Configure environment variables

Create a .env file:

DB_HOST=localhost
DB_PORT=5432
DB_USERNAME=postgres
DB_PASSWORD=your_password
DB_NAME=mutual_funds_loan
JWT_SECRET=your-super-secret-jwt-key-at-least-32-characters-long
JWT_EXPIRATION=1h
JWT_REFRESH_EXPIRATION=7d
MAX_LOGIN_ATTEMPTS=5
LOGIN_BLOCK_DURATION=900
PORT=8000
NODE_ENV=development

4. Create PostgreSQL database

psql -U postgres
CREATE DATABASE mutual_funds_loan;
\q

5. Run migrations

pnpm run migration:run

6. Start the backend server

# Development mode
pnpm run start:dev

# Production mode
pnpm run build
pnpm run start:prod

Backend will be running at: http://localhost:8000

Swagger Documentation: http://localhost:8000/api/docs

🎨 Frontend Setup

1. Navigate to frontend directory

cd frontend

2. Install dependencies

pnpm install

3. Start the development server

pnpm run dev

Frontend will be running at: http://localhost:3000

📚 API Endpoints

Authentication

• POST /auth/register - Register new user
• POST /auth/login - Login user
• POST /auth/logout - Logout current session
• POST /auth/logout-all - Logout from all devices
• POST /auth/refresh - Refresh access token
• GET /auth/profile - Get user profile (protected)

Session Management

• GET /auth/sessions - Get active sessions (protected)
• DELETE /auth/sessions/:id - Revoke specific session (protected)
• POST /auth/cleanup/manual - Manual cleanup (protected)

🗄️ Database Schema

Users Table

• id, email, password, firstName, lastName, phone, panNumber
• isActive, loginAttempts, lockedUntil, lastLoginAt
• createdAt, updatedAt

User Sessions Table

• id, userId, sessionToken, refreshToken
• deviceInfo (JSON), ipAddress, userAgent
• isActive, expiresAt, lastAccessedAt, createdAt

Blacklisted Tokens Table

• id, token, tokenType, reason, expiresAt, createdAt

🔐 Security Features

• Password Hashing: bcrypt with 12 salt rounds
• JWT Tokens: Secure access & refresh tokens
• HttpOnly Cookies: Prevents XSS attacks
• Token Blacklisting: Invalidates revoked tokens
• Account Lockout: 5 failed attempts = 15 min lockout
• Session Limits: Max 3 concurrent sessions per user
• Automatic Cleanup: Cron jobs remove expired tokens/sessions
• Environment Validation: Ensures required config exists

🧹 Cron Jobs

• Every Hour: Cleanup expired blacklisted tokens
• Every 6 Hours: Cleanup expired sessions
• Daily (Midnight): Full cleanup of both tokens and sessions

🧪 Testing with Swagger

1. Start the backend server
2. Navigate to http://localhost:8000/api/docs
3. Register a new user via /auth/register
4. Login via /auth/login to get tokens
5. Click "Authorize" and enter the access token
6. Test protected endpoints

📦 Additional Scripts

Backend

pnpm run build              # Build for production
pnpm run format             # Format code with Prettier
pnpm run lint               # Lint code with ESLint
pnpm run migration:generate # Generate new migration
pnpm run migration:revert   # Revert last migration

Frontend

pnpm run build              # Build for production
pnpm run start              # Start production server
pnpm run lint               # Check code with Biome
pnpm run format             # Format code with Biome