Sense AI Backend

A comprehensive backend API for Sense AI - an accessible AI assistant with real-time voice-to-text, text-to-speech, subscriptions, and wearable integrations.

🚀 Features

• Authentication System: JWT-based auth with access & refresh tokens
• OAuth Integration: Google and GitHub login support
• Subscription Management: Free and premium tiers with usage tracking
• User Management: Complete CRUD operations for user profiles
• Security: Rate limiting, input validation, password hashing
• Scalable Architecture: Clean MVC pattern with middleware
• MongoDB Integration: Mongoose ODM with advanced schemas

🛠️ Tech Stack

• Runtime: Node.js (ES6 modules)
• Framework: Express.js
• Database: MongoDB with Mongoose
• Authentication: JWT, Passport.js (Google/GitHub OAuth)
• Security: bcrypt, helmet, cors, rate limiting
• Validation: express-validator
• Development: nodemon, eslint

📁 Project Structure

src/
├── config/
│   ├── dbConfig.js          # MongoDB connection
│   └── passportConfig.js    # OAuth strategies
├── controllers/
│   └── authController.js    # Authentication logic
├── middleware/
│   ├── authMiddleware.js    # JWT authentication
│   ├── roleMiddleware.js    # Role-based access control
│   └── validationMiddleware.js # Input validation
├── models/
│   └── userModel.js         # User schema
├── routes/
│   └── authRoutes.js        # Authentication routes
├── utils/
│   └── tokenUtils.js        # JWT utilities
├── app.js                   # Express app configuration
└── server.js               # Server startup

🚀 Quick Start

Prerequisites

• Node.js (v18 or higher)
• MongoDB Atlas account or local MongoDB
• Google OAuth credentials (optional)
• GitHub OAuth credentials (optional)

Installation

1. Clone the repository

   git clone <repository-url>
   cd sense-ai-backend

2. Install dependencies

   npm install

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

   # Database Configuration
   MONGO_URI=mongodb+srv://senewtech:admin@senew-cluster.rg6pb.mongodb.net/sense_ai
   
   # JWT Configuration
   JWT_SECRET=your_super_secret_jwt_key_here_make_it_very_long_and_secure
   JWT_REFRESH_SECRET=your_super_secret_refresh_jwt_key_here_make_it_very_long_and_secure
   JWT_EXPIRE=15m
   JWT_REFRESH_EXPIRE=7d
   
   # OAuth Configuration (Optional)
   GOOGLE_CLIENT_ID=your_google_client_id_here
   GOOGLE_CLIENT_SECRET=your_google_client_secret_here
   GITHUB_CLIENT_ID=your_github_client_id_here
   GITHUB_CLIENT_SECRET=your_github_client_secret_here
   
   # Session Configuration
   SESSION_SECRET=your_session_secret_here_make_it_very_long_and_secure
   
   # Server Configuration
   PORT=5000
   NODE_ENV=development
   
   # CORS Configuration
   FRONTEND_URL=http://localhost:3000
   
   # Rate Limiting
   RATE_LIMIT_WINDOW_MS=900000
   RATE_LIMIT_MAX_REQUESTS=100

4. Start the server

   # Development mode
   npm run dev
   
   # Production mode
   npm start

The server will start on http://localhost:5000

📚 API Documentation

Base URL

• Development: http://localhost:5000
• Production: https://your-domain.com

Authentication

Include the JWT token in the Authorization header:

Authorization: Bearer <access_token>

Key Endpoints

Method	Endpoint	Description	Auth Required
POST	/api/auth/signup	Register new user	No
POST	/api/auth/login	Login user	No
POST	/api/auth/refresh	Refresh access token	No
POST	/api/auth/logout	Logout user	Yes
GET	/api/auth/profile	Get user profile	Yes
PUT	/api/auth/profile	Update profile	Yes
PUT	/api/auth/change-password	Change password	Yes
DELETE	/api/auth/account	Delete account	Yes
GET	/api/auth/usage	Get usage metrics	Yes
GET	/api/auth/google	Google OAuth	No
GET	/api/auth/github	GitHub OAuth	No

For detailed API documentation with request/response examples, see API_DOCUMENTATION.md

🧪 Testing with Postman

Import Collection

1. Open Postman
2. Import the collection from the repository
3. Set environment variables:
   • baseUrl: http://localhost:5000
   • accessToken: (will be set after login)

Sample Test Flow

1. Signup: Create a new user account
2. Login: Get access and refresh tokens
3. Get Profile: Retrieve user information
4. Update Profile: Modify user details
5. Get Usage: Check usage metrics
6. Logout: Invalidate tokens

🔒 Security Features

Password Security

• Minimum 8 characters
• Must contain uppercase, lowercase, number, and special character
• Bcrypt hashing with salt rounds of 12

JWT Security

• Access tokens expire in 15 minutes
• Refresh tokens expire in 7 days
• Tokens include user ID, email, and subscription tier

Rate Limiting

• Global: 100 requests per 15 minutes
• Auth endpoints: 5 attempts per 15 minutes
• Password change: 3 attempts per 15 minutes

Input Validation

• Email format validation
• Phone number validation
• Strong password requirements
• XSS protection

📊 Subscription Tiers

Free Tier

• Voice minutes: 10 per month
• Text characters: 1,000 per month
• API calls: 50 per month

Premium Tier

• Voice minutes: Unlimited
• Text characters: Unlimited
• API calls: Unlimited
• Advanced AI features
• Priority support

🚀 Deployment

Environment Variables for Production

NODE_ENV=production
PORT=5000
MONGO_URI=your_production_mongodb_uri
JWT_SECRET=your_production_jwt_secret
JWT_REFRESH_SECRET=your_production_refresh_secret
FRONTEND_URL=https://your-frontend-domain.com

Deployment Platforms

• Render: Easy deployment with automatic builds
• Heroku: Popular platform with add-ons
• AWS: EC2, ECS, or Lambda
• DigitalOcean: App Platform or Droplets

Docker Support (Optional)

FROM node:18-alpine
WORKDIR /app
COPY package*.json ./
RUN npm ci --only=production
COPY . .
EXPOSE 5000
CMD ["npm", "start"]

🛠️ Development

Available Scripts

npm start          # Start production server
npm run dev        # Start development server with nodemon
npm test           # Run tests
npm run lint       # Run ESLint
npm run lint:fix   # Fix ESLint errors

Code Style

• ES6 modules (import/export)
• camelCase file naming
• Comprehensive error handling
• Input validation
• Security best practices

🤝 Contributing

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Add tests if applicable
5. Submit a pull request

📝 License

This project is licensed under the MIT License.

🆘 Support

For support and questions:

• Create an issue in the repository
• Contact the development team
• Check the API documentation

🔮 Future Enhancements

• Email verification system
• Password reset functionality
• Admin panel
• Advanced analytics
• Webhook support
• API versioning
• GraphQL support
• Real-time features with Socket.io

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Built with ❤️ by the Sense AI Team