OpenAI Assistant API with FastAPI

A FastAPI-based web service that integrates with OpenAI's Assistant API to create conversational AI applications with function calling capabilities.

Features

• 🤖 OpenAI Assistant Integration: Seamless integration with OpenAI's Assistant API
• 🔧 Function Calling: Support for custom function execution during conversations
• 🧵 Thread Management: Conversation thread creation and management
• 🚀 FastAPI Framework: High-performance async web framework
• 📝 Booking System: Example booking function implementation
• ⚡ Real-time Processing: Asynchronous message processing

Prerequisites

• Python 3.8+
• OpenAI API key
• OpenAI Assistant ID

Installation

1. Clone the repository

   git clone <your-repository-url>
   cd <repository-name>

2. Install dependencies

   pip install -r requirements.txt

3. Environment Setup

   Create a .env file in the root directory and add your credentials:

   OPENAI_API_KEY=your_openai_api_key_here
   CHATBOT_ASSISTANT_ID=your_assistant_id_here

   Important: Update the main.py file to load these environment variables:

   import os
   from dotenv import load_dotenv
   
   load_dotenv()
   OPENAI_API_KEY = os.getenv("OPENAI_API_KEY")
   CHATBOT_ASSISTANT_ID = os.getenv("CHATBOT_ASSISTANT_ID")

Usage

Starting the Server

Run the FastAPI server:

python main.py

The server will start on http://0.0.0.0:8001

API Endpoints

1. Start a New Conversation

GET /start

Response:

{
  "thread_id": "thread_abc123"
}

2. Send a Message

POST /chat

Request Body:

{
  "thread_id": "thread_abc123",
  "message": "Hello, I'd like to make a booking"
}

Response:

{
  "response": "Hello! I'd be happy to help you with your booking..."
}

Example Usage with curl

1. Start a conversation:

   curl -X GET http://localhost:8001/start

2. Send a message:

   curl -X POST http://localhost:8001/chat \
     -H "Content-Type: application/json" \
     -d '{
       "thread_id": "your_thread_id",
       "message": "I want to book an appointment"
     }'

Function Calling

The application includes an example booking function that can be called by the OpenAI Assistant:

def prenota(nome, numero_cel, riassunto_breve_chat):
    """
    Example booking function
    
    Args:
        nome (str): Customer name
        numero_cel (str): Phone number
        riassunto_breve_chat (str): Brief chat summary
    
    Returns:
        str: Confirmation message
    """

Adding Custom Functions

To add new functions:

1. Define your function in main.py
2. Add it to the available_functions dictionary
3. Configure the function in your OpenAI Assistant settings

Project Structure

.
├── main.py              # Main FastAPI application
├── requirements.txt     # Python dependencies
├── README.md           # Project documentation
└── .env               # Environment variables (create this)

Dependencies

• FastAPI: Modern web framework for building APIs
• OpenAI: Official OpenAI Python client
• Uvicorn: ASGI server for FastAPI
• Pydantic: Data validation using Python type annotations
• python-dotenv: Load environment variables from .env file

Configuration

OpenAI Version Compatibility

The application requires OpenAI Python client version 1.1.1 or higher. The version check is performed automatically on startup.

Server Configuration

Default server configuration:

• Host: 0.0.0.0 (all interfaces)
• Port: 8001

To change these settings, modify the uvicorn.run() call in main.py.

Error Handling

The application handles various scenarios:

• Missing thread ID
• OpenAI API errors
• Function execution errors
• Assistant run failures

Security Considerations

⚠️ Important Security Notes:

1. Never commit API keys to version control
2. Use environment variables for sensitive data
3. Implement proper authentication for production use
4. Validate and sanitize function inputs
5. Set up CORS if needed for web frontend integration

Development

Running in Development Mode

For development with auto-reload:

uvicorn main:app --reload --host 0.0.0.0 --port 8001

Testing

Test the API endpoints using:

• FastAPI's automatic interactive documentation at http://localhost:8001/docs
• Postman or similar API testing tools
• curl commands as shown in the usage examples

Contributing

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

License

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

Support

If you encounter any issues or have questions:

1. Check the OpenAI API documentation
2. Review the FastAPI documentation
3. Open an issue in this repository

Changelog

v1.0.0

• Initial release
• OpenAI Assistant API integration
• Basic function calling support
• FastAPI web service implementation