This guide provides a comprehensive walkthrough on integrating OpenRouter models into the Pydantic AI framework using the openrouter-agent Python package. We'll cover installation, API key management, CLI usage, Python integration, and best practices for secure development.

Installation and Setup

The first step is installing the openrouter-agent package using pip:

bash pip install openrouter-agent==0.1.0

This package bridges the gap between Pydantic AI's powerful framework and the diverse models offered by OpenRouter, leveraging OpenRouter's OpenAI-compatible API.

API Key Management: Security Best Practices

Securely managing your OpenRouter API key is crucial. The recommended approach is using environment variables:

1. Using Environment Variables

This method prevents hardcoding your API key directly into your code, significantly enhancing security.

• Create a .env file: In your project's root directory, create a file named .env. If you have a .env-sample or .env.example file, copy it and rename it to .env.
• Add your API key: Open the .env file and add the following line, replacing your_actual_api_key with your actual OpenRouter API key obtained from the OpenRouter Keys section of your account:

OPENROUTER_API_KEY=your_actual_api_key

• Load the environment variables: To access this variable within your Python code, you'll need the python-dotenv library. Install it using:

bash pip install python-dotenv

Then, load it at the beginning of your Python script:

```python from dotenv import load_dotenv import os

loaddotenv() # Load environment variables from .env openrouterapikey = os.getenv("OPENROUTERAPI_KEY")

... rest of your code using openrouterapikey ...

```

Some frameworks (like Django or Flask) might automatically load .env files, eliminating the need for explicit loading. Check your framework's documentation for details.

2. Setting the API Key Directly (Less Secure)

While less secure, you can set the API key directly in your terminal for quick testing:

• Linux/macOS/Git Bash:

bash export OPENROUTER_API_KEY=your_actual_api_key

• Windows Command Prompt:

bash set OPENROUTER_API_KEY=your_actual_api_key

• Windows PowerShell:

powershell $env:OPENROUTER_API_KEY = "your_actual_api_key"

Important: This method requires setting the environment variable each time you open a new terminal session.

3. Version Control and Security

Never commit your .env file to version control (like Git). Add .env to your .gitignore file to prevent accidental exposure of your API key.

Using the openrouter-agent CLI

The package provides a command-line interface for quick model interaction. You can generate and execute shell commands directly:

bash openrouter-agent --model <model_identifier> --prompt "<your_prompt>"

Replace <model_identifier> with the desired OpenRouter model ID and <your_prompt> with your input prompt. For example:

bash openrouter-agent --model text-davinci-003 --prompt "Write a short story about a talking dog."

Python Integration: Advanced Usage

For more complex integration within your Python applications, you can directly import and utilize the core classes:

```python from openrouter_agent import OpenRouterModel, OpenRouterAgent

Initialize OpenRouterModel

openroutermodel = OpenRouterModel(modelname="text-davinci-003", apikey=openrouterapi_key)

Generate a completion

response = openrouter_model.complete("What is the capital of France?") print(response)

Initialize OpenRouterAgent

agent = OpenRouterAgent(model=openrouter_model)

Use the agent for more complex interactions

The OpenRouterModel class extends the OpenAIModel class, providing seamless integration with OpenRouter's API. The OpenRouterAgent class utilizes OpenRouterModel for completions, offering an agent-based interface for more sophisticated applications.

Choosing the Right OpenRouter Model

OpenRouter offers a wide array of models, each suited for different tasks. Some popular choices include:

• text-davinci-003: A powerful general-purpose model suitable for various text generation tasks, including creative writing, summarization, and translation.
• code-davinci-002: Specifically designed for code generation and related tasks.
• text-curie-001: A more cost-effective option for simpler text generation tasks.
• text-babbage-001: A budget-friendly model, ideal for basic text generation and simpler applications.

Consult the OpenRouter documentation for a complete list of available models and their capabilities to select the best fit for your specific needs. Consider factors like cost, performance, and the complexity of your task.

Error Handling and Best Practices

Robust error handling is essential. Always anticipate potential issues, such as API rate limits, network errors, and invalid API keys. Implement proper exception handling to gracefully manage these scenarios. For example:

python try: response = openrouter_model.complete("Your prompt") except Exception as e: print(f"An error occurred: {e}") # Implement appropriate logging or error reporting mechanisms

Furthermore, consider using asynchronous programming (asyncio) for performance improvements, especially when dealing with multiple API requests.

Expanding Capabilities with Pydantic AI

The combination of OpenRouter models and the Pydantic AI framework allows for extensive customization. You can leverage Pydantic's data validation and schema definition capabilities to ensure data consistency and improve the reliability of your applications. This is particularly useful when processing complex structured data or integrating with other systems.

Conclusion

The openrouter-agent package simplifies the integration of OpenRouter's diverse models into your Pydantic AI applications. By following the best practices outlined in this guide, you can build secure, robust, and efficient applications leveraging the power of both frameworks. Remember to always consult the official documentation for both OpenRouter and Pydantic AI for the most up-to-date information and best practices. The flexibility and power of this combination open up a world of possibilities for building innovative AI-powered solutions.