Refactor: Add LLM provider utilities and improve API base URL detection (#12766)

Co-authored-by: openhands <openhands@all-hands.dev>

openhands/utils/llm.py

@@ -5,12 +5,68 @@ import httpx
 with warnings.catch_warnings():
     warnings.simplefilter('ignore')
     import litellm
+    from litellm import LlmProviders, ProviderConfigManager, get_llm_provider
 
 from openhands.core.config import LLMConfig, OpenHandsConfig
 from openhands.core.logger import openhands_logger as logger
 from openhands.llm import bedrock
 
 
+def is_openhands_model(model: str | None) -> bool:
+    """Check if the model uses the OpenHands provider.
+
+    Args:
+        model: The model name to check.
+
+    Returns:
+        True if the model starts with 'openhands/', False otherwise.
+    """
+    return bool(model and model.startswith('openhands/'))
+
+
+def get_provider_api_base(model: str) -> str | None:
+    """Get the API base URL for a model using litellm.
+
+    This function tries multiple approaches to determine the API base URL:
+    1. First tries litellm.get_api_base() which handles OpenAI, Gemini, Mistral
+    2. Falls back to ProviderConfigManager.get_provider_model_info() for providers
+       like Anthropic that have ModelInfo classes with get_api_base() methods
+
+    Args:
+        model: The model name (e.g., 'gpt-4', 'anthropic/claude-sonnet-4-5-20250929')
+
+    Returns:
+        The API base URL if found, None otherwise.
+    """
+    # First try get_api_base (handles OpenAI, Gemini with specific URL patterns)
+    try:
+        api_base = litellm.get_api_base(model, {})
+        if api_base:
+            return api_base
+    except Exception:
+        pass
+
+    # Fall back to ProviderConfigManager for providers like Anthropic
+    try:
+        # Get the provider from the model
+        _, provider_name, _, _ = get_llm_provider(model)
+        if provider_name:
+            # Convert provider name to LlmProviders enum
+            try:
+                provider_enum = LlmProviders(provider_name)
+                model_info = ProviderConfigManager.get_provider_model_info(
+                    model, provider_enum
+                )
+                if model_info and hasattr(model_info, 'get_api_base'):
+                    return model_info.get_api_base()
+            except ValueError:
+                pass  # Provider not in enum
+    except Exception:
+        pass
+
+    return None
+
+
 def get_supported_llm_models(config: OpenHandsConfig) -> list[str]:
     """Get all models supported by LiteLLM.