Feature Request: Support custom OpenAI endpoint URL for OpenAI provider #6490
Description
Is your feature request related to a problem? Please describe.
The current OpenAI provider does not support configuring a custom OpenAI endpoint URL, which makes it impossible to use OpenAI-compatible third-party services (e.g., SiliconFlow). These services follow the OpenAI API format but require pointing to their own endpoint URLs instead of the official OpenAI endpoint.
Describe the solution you'd like
Add a configurable openai endpoint url field/parameter to the OpenAI provider, so users can manually specify the API endpoint URL when using OpenAI-compatible services.
Describe alternatives you've considered
- Switching to a dedicated provider for SiliconFlow: Not ideal, as it breaks the unified OpenAI-compatible usage pattern.
- Hardcoding the endpoint: Not flexible for different OpenAI-compatible providers.
Additional context
Many cloud / inference providers (SiliconFlow, etc.) provide OpenAI-compatible APIs, only differing in the endpoint URL. Supporting custom endpoints will greatly improve the compatibility and flexibility of the OpenAI provider.