ArtLoop Backend

Backend service for ArtLoop - that transforms hand-drawn sketches into stunning artwork using advanced image analysis and generation.

Table of Contents

• Overview
• Features
• Tech Stack
• Architecture
• API Endpoints
• Setup and Installation
• Environment Variables
• Project Structure
• Services
• Contributing
• License

Overview

ArtLoop Backend is the server-side component of the ArtLoop application. It provides RESTful APIs for user authentication, sketch analysis, and AI-powered image generation. The service integrates with Google Cloud Vision for image analysis and Together AI for image generation.

Features

• User authentication (registration and login)
• Sketch analysis using Google Cloud Vision API
• AI-powered image generation using Together AI
• Credit-based usage system
• Multiple artistic style presets
• Secure JWT-based authentication

Tech Stack

• Runtime: Node.js
• Framework: Express.js
• Authentication: JWT (JSON Web Tokens)
• Database: Appwrite
• Image Analysis: Google Cloud Vision API
• Image Generation: Together AI
• CORS: Enabled for specific origins

Architecture

The backend follows a modular architecture with clear separation of concerns:

├── config/          # Configuration files for services
├── middlewares/     # Authentication and other middleware functions
├── routes/          # API route definitions
├── services/        # Business logic and service integrations
├── server.js        # Entry point

API Endpoints

Authentication

• POST /api/auth/register - Register a new user
• POST /api/auth/login - Login for existing users

Image Generation

• POST /api/generate - Generate artwork from sketch (requires authentication)

Setup and Installation

1. Clone the repository:

   git clone <repository-url>
   cd artloop-backend

2. Install dependencies:

   npm install

3. Set up environment variables (see Environment Variables)

4. Start the development server:

   npm run dev

5. For production:

   npm start

Environment Variables

Create a .env file in the root directory with the following variables:

# Server Configuration
PORT=3000
JWT_SECRET=your_jwt_secret_key

# Appwrite Configuration
VITE_APPWRITE_ENDPOINT=your_appwrite_endpoint
VITE_APPWRITE_PROJECT_ID=your_appwrite_project_id
VITE_APPWRITE_API_KEY=your_appwrite_api_key
VITE_APPWRITE_DATABASE_ID=your_appwrite_database_id
VITE_APPWRITE_USERS_COLLECTION_ID=your_users_collection_id

# Together AI Configuration
TOGETHER_AI_API_KEY=your_together_ai_api_key

# Google Cloud Vision (key file should be in root)
# artloop-466212-6e252fad9d85.json

Project Structure

artloop-backend/
├── config/
│   ├── ai.js          # AI service configurations
│   └── database.js    # Database configurations
├── middlewares/
│   └── auth.js        # Authentication middleware
├── routes/
│   ├── auth.js        # Authentication routes
│   ├── generate.js    # Image generation routes
├── services/
│   ├── imageService.js # Image generation service
│   └── visionService.js # Image analysis service
├── .env               # Environment variables
├── server.js          # Entry point
├── package.json       # Dependencies and scripts
└── README.md          # This file

Services

Google Cloud Vision Integration

The application uses Google Cloud Vision API for analyzing user sketches. The service extracts:

• Object detection
• Text detection
• Image properties (dominant colors)
• Web detection
• Label detection

Together AI Integration

ArtLoop uses Together AI's FLUX.1-schnell-Free model for generating final artwork from analyzed sketches. Users can select from multiple artistic styles:

• Realistic
• Anime
• Cartoon
• Oil Paint
• Sketch
• Cyberpunk

Appwrite Integration

Appwrite is used as the backend database for:

• User management
• Credit tracking
• Session management

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