fixes to test

litellm/responses/main.py

@@ -10,6 +10,9 @@ from litellm.constants import request_timeout
 from litellm.litellm_core_utils.litellm_logging import Logging as LiteLLMLoggingObj
 from litellm.llms.base_llm.responses.transformation import BaseResponsesAPIConfig
 from litellm.llms.custom_httpx.llm_http_handler import BaseLLMHTTPHandler
+from litellm.responses.litellm_completion_transformation.handler import (
+    LiteLLMCompletionTransformationHandler,
+)
 from litellm.responses.utils import ResponsesAPIRequestUtils
 from litellm.types.llms.openai import (
     Reasoning,
@@ -29,6 +32,7 @@ from .streaming_iterator import BaseResponsesAPIStreamingIterator
 ####### ENVIRONMENT VARIABLES ###################
 # Initialize any necessary instances or variables here
 base_llm_http_handler = BaseLLMHTTPHandler()
+litellm_completion_transformation_handler = LiteLLMCompletionTransformationHandler()
 #################################################
 
 
@@ -178,19 +182,12 @@ def responses(
         )
 
         # get provider config
-        responses_api_provider_config: Optional[
-            BaseResponsesAPIConfig
-        ] = ProviderConfigManager.get_provider_responses_api_config(
-            model=model,
-            provider=litellm.LlmProviders(custom_llm_provider),
-        )
-
-        if responses_api_provider_config is None:
-            raise litellm.BadRequestError(
+        responses_api_provider_config: Optional[BaseResponsesAPIConfig] = (
+            ProviderConfigManager.get_provider_responses_api_config(
                 model=model,
-                llm_provider=custom_llm_provider,
-                message=f"Responses API not available for custom_llm_provider={custom_llm_provider}, model: {model}",
+                provider=litellm.LlmProviders(custom_llm_provider),
             )
+        )
 
         local_vars.update(kwargs)
         # Get ResponsesAPIOptionalRequestParams with only valid parameters
@@ -200,6 +197,16 @@ def responses(
             )
         )
 
+        if responses_api_provider_config is None:
+            return litellm_completion_transformation_handler.response_api_handler(
+                model=model,
+                input=input,
+                responses_api_request=ResponsesAPIOptionalRequestParams(),
+                custom_llm_provider=custom_llm_provider,
+                _is_async=_is_async,
+                **kwargs,
+            )
+
         # Get optional parameters for the responses API
         responses_api_request_params: Dict = (
             ResponsesAPIRequestUtils.get_optional_params_responses_api(