Bug Description:
The .env.example file has a configuration parameter for OPENAI_BASE_URL, indicating that this URL will be used for API calls. However, this parameter is not used anywhere in the code.

Steps To Reproduce:
Steps to reproduce the bug behavior:

1. Provide a custom URL for the OPENAI_BASE_URL parameter in your .env file
2. Run the application as per instructions (e.g., using Docker)
3. The underlying calls will still go to https://api.openai.com/v1

Expected behavior:
When an OPENAI_BASE_URL is provided, calls to the OpenAI endpoints should be routed to the URL specified in the parameter.

Library version:
0.1.0