This enhancement allows inference providers using LiteLLMOpenAIMixin to validate
model availability against LiteLLM's official provider model listings, improving
reliability and user experience when working with different AI service providers.
- Add litellm_provider_name parameter to LiteLLMOpenAIMixin constructor
- Add check_model_availability method to LiteLLMOpenAIMixin using litellm.models_by_provider
- Update Gemini, Groq, and SambaNova inference adapters to pass litellm_provider_name