Real Estate Backend with Multiple Roles

A comprehensive Node.js backend application for real estate tokenization platform. This system enables secure management of real estate assets through blockchain technology, featuring multi-role authentication, KYC verification, and advanced real estate management capabilities.

Key Features

Authentication & Authorization

• Multi-role user system (Admin, Node Operator, User)
• JWT-based authentication with refresh token mechanism
• Role-based access control (RBAC)
• Signature verification for blockchain transactions
• Session management and token blacklisting

Security

• Password hashing using bcrypt with salt rounds
• API key validation for sensitive endpoints
• Rate limiting to prevent brute force attacks
• CORS configuration with whitelisted origins
• XSS protection and security headers
• Request data validation and sanitization
• SQL injection prevention
• Secure HTTP-only cookies

Real Estate Management

• Property tokenization system
• Real estate value assessment
• Percentage-based tokenization
• Property documentation management
• Transaction history tracking
• Asset verification system

User Management

• Comprehensive KYC verification system
• User profile management
• ETH address validation and verification
• Role-specific permissions
• Activity logging and monitoring

System Features

• Advanced filtering, sorting, and pagination
• Comprehensive error handling and logging
• Database indexing for optimized queries
• Caching system for improved performance
• Automated backup system
• Request rate limiting
• Input validation and sanitization

Prerequisites

• Node.js (v14 or higher)
• MongoDB (v4.4 or higher)
• npm or yarn
• Git

Tech Stack

• Runtime: Node.js
• Framework: Express.js
• Database: MongoDB with Mongoose ODM
• Authentication: JWT, Passport.js
• Validation: Express-validator
• Security: Helmet.js, CORS, Rate-limit
• Documentation: Swagger/OpenAPI
• Testing: Jest, Supertest
• Logging: Winston
• Development: Nodemon, ESLint, Prettier

Installation

1. Clone the repository:

git clone <repository-url>
cd estate_backend

2. Install dependencies:

npm install

3. Create a .env file in the root directory:

# Server Configuration
PORT=5000
NODE_ENV=development

# Database Configuration
DATABASE_URL=your_mongodb_connection_string
DATABASE_PASSWORD=your_database_password

# JWT Configuration
JWT_SECRET=your_jwt_secret
JWT_EXPIRES_IN=90d
JWT_COOKIE_EXPIRES_IN=90

# API Security
API_KEY=your_api_key
RATE_LIMIT_WINDOW_MS=900000
RATE_LIMIT_MAX=100

# Blockchain Configuration
BLOCKCHAIN_NETWORK=ethereum
SMART_CONTRACT_ADDRESS=your_contract_address

# Email Configuration (optional)
EMAIL_HOST=smtp.mailtrap.io
EMAIL_PORT=2525
EMAIL_USERNAME=your_username
EMAIL_PASSWORD=your_password

Project Structure

estate_backend/
├── controllers/          # Route controllers
│   ├── authController.js    # Authentication logic
│   ├── userController.js    # User management
│   └── nodeController.js    # Node operations
├── middleware/          # Custom middleware
│   ├── auth.js            # Authentication middleware
│   └── validator.js       # Input validation
├── models/             # Database models
│   ├── userModel.js       # User schema
│   └── nodeModel.js       # Node schema
├── routes/             # API routes
│   ├── adminRoutes.js     # Admin endpoints
│   ├── nodeRoutes.js      # Node endpoints
│   └── userRoutes.js      # User endpoints
├── utils/             # Utility functions
│   ├── apiFeatures.js     # API utilities
│   └── errorHandler.js    # Error handling
├── config/            # Configuration files
│   └── database.js       # Database configuration
├── tests/             # Test files
│   ├── unit/            # Unit tests
│   └── integration/     # Integration tests
├── logs/              # Application logs
├── docs/              # Documentation
├── .env               # Environment variables
├── server.js          # Application entry point
└── vercel.json        # Vercel deployment config

API Documentation

Authentication

Admin Authentication

• POST /api/v1/admin/signup

  • Create new admin account
  • Required fields: name, email, password, ethAddress
  • Returns: JWT token, admin details

• POST /api/v1/admin/login

  • Admin login
  • Required fields: email, password
  • Returns: JWT token, admin details

Node Authentication

• POST /api/v1/node/signup

  • Register new node operator
  • Required fields: name, email, password, ethAddress, vaultAddress, paymentToken, signature
  • Returns: JWT token, node details

• POST /api/v1/node/login

  • Node operator login
  • Required fields: email, password
  • Returns: JWT token, node details

User Authentication

• POST /api/v1/user/register
  • Register new user
  • Required fields: name, email, password, ethAddress, country, state, address, kycType, kycId
  • Optional fields: realEstateInfo, currentEstateCost, percentageToTokenize
  • Returns: JWT token, user details

User Management

Admin Operations

• GET /api/v1/admin/users

  • Get all users
  • Query parameters supported
  • Requires: Admin authentication

• GET /api/v1/admin/nodes

  • Get all nodes
  • Query parameters supported
  • Requires: Admin authentication

• PATCH /api/v1/admin/nodes/:id/approve

  • Approve node operator
  • Requires: Admin authentication
  • Returns: Updated node details

User Operations

• GET /api/v1/user/profile

  • Get user profile
  • Requires: User authentication

• PATCH /api/v1/user/profile

  • Update user profile
  • Requires: User authentication
  • Returns: Updated user details

Query Parameters

All list endpoints support these parameters:

Filtering

GET /api/v1/users?country=USA&state=California
GET /api/v1/users?currentEstateCost[gte]=100000
GET /api/v1/users?createdAt[gte]=2024-01-01

Sorting

GET /api/v1/users?sort=name,-createdAt
GET /api/v1/users?sort=-currentEstateCost

Pagination

GET /api/v1/users?page=2&limit=10

Field Selection

GET /api/v1/users?fields=name,email,country

Error Handling

Error Response Format

{
  "status": "error",
  "message": "Detailed error message",
  "code": "ERROR_CODE",
  "timestamp": "2024-01-11T16:31:45.000Z",
  "path": "/api/v1/users",
  "details": {
    "field": "email",
    "issue": "Invalid email format"
  }
}

Common Error Codes

• AUTH_001: Authentication failed
• AUTH_002: Invalid token
• AUTH_003: Token expired
• VAL_001: Validation error
• REQ_001: Bad request
• NOT_FOUND: Resource not found
• SERVER_ERROR: Internal server error

Development

1. Start development server:

npm run dev

2. Run tests:

npm run test
npm run test:coverage

3. Lint code:

npm run lint
npm run lint:fix

4. Generate API documentation:

npm run docs

Production Deployment

1. Build the application:

npm run build

2. Start production server:

npm start

Deployment Checklist

• Set NODE_ENV to 'production'
• Configure production database
• Set up proper SSL/TLS certificates
• Configure production logging
• Set up monitoring and alerting
• Configure backup system
• Set up CI/CD pipeline

Monitoring and Logging

The application uses Winston for logging with different log levels:

• ERROR: Application errors
• WARN: Warning messages
• INFO: General information
• DEBUG: Debugging information

Logs are stored in:

• logs/error.log: Error messages
• logs/combined.log: All logs
• Console: Development environment logs

Performance Optimization

• Database indexing for frequently queried fields
• Response caching for static content
• Rate limiting for API endpoints
• Compression for response payload
• Connection pooling for database
• Efficient query optimization

Security Measures

1. Authentication

   • JWT token validation
   • Password hashing
   • Token refresh mechanism
   • Session management

2. Authorization

   • Role-based access control
   • API key validation
   • Resource-level permissions

3. Data Protection

   • Input sanitization
   • XSS protection
   • CSRF protection
   • SQL injection prevention

4. Network Security

   • CORS configuration
   • Rate limiting
   • Security headers
   • HTTPS enforcement

Contributing

1. Fork the repository
2. Create your feature branch: git checkout -b feature/AmazingFeature
3. Commit your changes: git commit -m 'Add some AmazingFeature'
4. Push to the branch: git push origin feature/AmazingFeature
5. Open a Pull Request

Coding Standards

• Follow ESLint configuration
• Write unit tests for new features
• Update documentation
• Follow semantic versioning

Support

For support, email support@example.com or join our Slack channel.

License

This project is licensed under the MIT License - see the LICENSE file for details.

Acknowledgments

• Express.js team
• MongoDB team
• Node.js community
• All contributors