add should_fake_stream

litellm/llms/base_llm/responses/transformation.py

@@ -131,3 +131,12 @@ class BaseResponsesAPIConfig(ABC):
             message=error_message,
             headers=headers,
         )
+
+    def should_fake_stream(
+        self,
+        model: Optional[str],
+        stream: Optional[bool],
+        custom_llm_provider: Optional[str] = None,
+    ) -> bool:
+        """Returns True if litellm should fake a stream for the given model and stream value"""
+        return False

litellm/llms/openai/responses/transformation.py

@@ -188,3 +188,27 @@ class OpenAIResponsesAPIConfig(BaseResponsesAPIConfig):
             raise ValueError(f"Unknown event type: {event_type}")
 
         return model_class
+
+    def should_fake_stream(
+        self,
+        model: Optional[str],
+        stream: Optional[bool],
+        custom_llm_provider: Optional[str] = None,
+    ) -> bool:
+        if stream is not True:
+            return False
+        if model is not None:
+            try:
+                if (
+                    litellm.utils.supports_native_streaming(
+                        model=model,
+                        custom_llm_provider=custom_llm_provider,
+                    )
+                    is False
+                ):
+                    return True
+            except Exception as e:
+                verbose_logger.debug(
+                    f"Error getting model info in OpenAIResponsesAPIConfig: {e}"
+                )
+        return False

litellm/utils.py

@@ -1975,6 +1975,27 @@ def supports_system_messages(model: str, custom_llm_provider: Optional[str]) ->
     )
 
 
+def supports_native_streaming(model: str, custom_llm_provider: Optional[str]) -> bool:
+    """
+    Check if the given model supports native streaming and return a boolean value.
+
+    Parameters:
+    model (str): The model name to be checked.
+    custom_llm_provider (str): The provider to be checked.
+
+    Returns:
+    bool: True if the model supports native streaming, False otherwise.
+
+    Raises:
+    Exception: If the given model is not found in model_prices_and_context_window.json.
+    """
+    return _supports_factory(
+        model=model,
+        custom_llm_provider=custom_llm_provider,
+        key="supports_native_streaming",
+    )
+
+
 def supports_response_schema(
     model: str, custom_llm_provider: Optional[str] = None
 ) -> bool: