Oneline Chat

A modern, real-time streaming chat application built with FastAPI (Python) backend and React TypeScript frontend.

🏗️ Project Structure

oneline-chat/
├── backend/          # FastAPI Python backend
│   ├── src/         # Source code
│   ├── tests/       # Test files
│   └── requirements.txt
├── ui/              # React TypeScript frontend
│   ├── src/         # Source code
│   └── package.json
├── docker-compose.yml
└── README.md

✨ Features

Backend (FastAPI + Python)

• 🔄 Real-time streaming chat via Server-Sent Events (SSE)
• 🤖 AI Integration with OpenAI/Ollama support
• 🗄️ PostgreSQL database with SQLModel ORM
• 🔧 Configurable settings via environment variables
• 📝 Comprehensive logging and error handling
• 🧪 Full test coverage with pytest

Frontend (React + TypeScript)

• 💬 Modern chat interface with real-time streaming
• 🌓 Dark/light mode support
• 📱 Responsive design with Tailwind CSS
• ⚙️ Chat settings (model selection, temperature, etc.)
• 📡 Axios HTTP client with interceptors
• 🔧 Configurable API endpoints via environment variables

🚀 Quick Start

Prerequisites

• Node.js 18+
• Python 3.11+
• PostgreSQL 14+
• npm/yarn

Backend Setup

cd backend
pip install -r requirements.txt
python -m oneline_chat.main

Frontend Setup

cd ui
npm install
npm run dev

Environment Variables

Backend (.env in /backend):

DB_HOST=localhost
DB_PORT=5432
DB_USER=postgres
DB_PASSWORD=your_password
DB_NAME=oneline_chat_app
AI_PROVIDER=ollama
OLLAMA_BASE_URL=http://localhost:11434/v1
OLLAMA_MODEL=deepseek-r1:8b

Frontend (.env in /ui):

VITE_API_BASE_URL=http://localhost:8000
VITE_API_TIMEOUT=30000

🐳 Docker Setup

docker-compose up -d

This will start:

• PostgreSQL database
• FastAPI backend
• React frontend
• Nginx reverse proxy

📚 API Documentation

Once the backend is running, visit:

• Swagger UI: http://localhost:8000/docs
• ReDoc: http://localhost:8000/redoc

Main Endpoints

• POST /api/v1/chat/stream - Streaming chat endpoint
• POST /api/v1/chat/completions - Non-streaming chat
• GET /api/v1/chat/history/{chat_id} - Chat history
• GET /api/v1/models - Available models

🛠️ Development

Backend Development

cd backend
pip install -r requirements.txt
pytest  # Run tests
python -m oneline_chat.main  # Start server

Frontend Development

cd ui
npm install
npm run dev     # Start dev server
npm run build   # Build for production
npm run lint    # Run linting

🏛️ Architecture

Backend Stack

• FastAPI - Modern Python web framework
• SQLModel - SQLAlchemy + Pydantic for database ORM
• PostgreSQL - Primary database
• Pydantic Settings - Configuration management
• Uvicorn - ASGI server

Frontend Stack

• React 18 - UI framework
• TypeScript - Type safety
• Vite - Build tool and dev server
• Tailwind CSS - Utility-first styling
• Axios - HTTP client with interceptors

Communication

• REST API for standard operations
• Server-Sent Events (SSE) for real-time streaming
• JSON for data exchange

🧪 Testing

Backend Tests

cd backend
pytest
pytest --cov  # With coverage

Frontend Tests

cd ui
npm test

📦 Deployment

Production Build

# Backend
cd backend
pip install -r requirements.txt
python -m oneline_chat.main

# Frontend
cd ui
npm install
npm run build
npm run preview

Docker Deployment

docker-compose -f docker-compose.prod.yml up -d

🤝 Contributing

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

📄 License

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

🔧 Configuration

Chat Modes

• Single: Single AI agent responds
• Multiple: Multiple AI agents can participate

Supported Models

• DeepSeek R1 8B (default)
• GPT-3.5 Turbo
• GPT-4
• Claude 3 Haiku/Sonnet

Settings

• Temperature: 0.0-2.0 (creativity level)
• Max Tokens: 50-4000 (response length)
• Save to DB: Toggle conversation persistence