fix(openai): include 'user' param for responses API models

litellm/llms/openai/chat/gpt_transformation.py

@@ -168,9 +168,11 @@ def get_supported_openai_params(self, model: str) -> list:
         ):  # gpt-4 does not support 'response_format'
             model_specific_params.append("response_format")
 
+        # Normalize model name for responses API (e.g., "responses/gpt-4.1" -> "gpt-4.1")
+        model_for_check = model.split("responses/", 1)[1] if "responses/" in model else model
         if (
-            model in litellm.open_ai_chat_completion_models
-        ) or model in litellm.open_ai_text_completion_models:
+            model_for_check in litellm.open_ai_chat_completion_models
+        ) or model_for_check in litellm.open_ai_text_completion_models:
             model_specific_params.append(
                 "user"
             )  # user is not a param supported by all openai-compatible endpoints - e.g. azure ai

tests/test_litellm/llms/openai/chat/test_openai_gpt_transformation.py

@@ -0,0 +1,125 @@
+"""
+Tests for OpenAI GPT transformation (litellm/llms/openai/chat/gpt_transformation.py)
+"""
+
+import pytest
+import sys
+import os
+
+sys.path.insert(0, os.path.abspath("../../../../.."))
+
+from litellm.llms.openai.chat.gpt_transformation import OpenAIGPTConfig
+
+
+class TestOpenAIGPTConfig:
+    """Tests for OpenAIGPTConfig class"""
+
+    def setup_method(self):
+        self.config = OpenAIGPTConfig()
+
+    def test_user_param_supported_for_regular_models(self):
+        """Test that 'user' param is in supported params for regular OpenAI models."""
+        supported_params = self.config.get_supported_openai_params("gpt-4o")
+        assert "user" in supported_params
+
+        supported_params = self.config.get_supported_openai_params("gpt-4.1-mini")
+        assert "user" in supported_params
+
+    def test_user_param_supported_for_responses_api_models(self):
+        """Test that 'user' param is in supported params for responses API models.
+
+        Regression test for: https://github.com/BerriAI/litellm/issues/17633
+        When using model="openai/responses/gpt-4.1", the 'user' parameter should
+        be included in supported params so it reaches OpenAI and SpendLogs.
+        """
+        # responses/gpt-4.1-mini should support 'user' just like gpt-4.1-mini
+        supported_params = self.config.get_supported_openai_params("responses/gpt-4.1-mini")
+        assert "user" in supported_params
+
+        supported_params = self.config.get_supported_openai_params("responses/gpt-4o")
+        assert "user" in supported_params
+
+        supported_params = self.config.get_supported_openai_params("responses/gpt-4.1")
+        assert "user" in supported_params
+
+    def test_model_normalization_for_responses_prefix(self):
+        """Test that models with 'responses/' prefix are normalized correctly.
+
+        The fix normalizes 'responses/gpt-4.1' to 'gpt-4.1' when checking
+        if the model is in the list of supported OpenAI models.
+        """
+        # Both should have the same supported params
+        regular_params = self.config.get_supported_openai_params("gpt-4.1-mini")
+        responses_params = self.config.get_supported_openai_params("responses/gpt-4.1-mini")
+
+        # 'user' should be in both
+        assert "user" in regular_params
+        assert "user" in responses_params
+
+    def test_base_params_always_included(self):
+        """Test that base params are always included regardless of model."""
+        base_expected_params = [
+            "frequency_penalty",
+            "max_tokens",
+            "temperature",
+            "top_p",
+            "stream",
+            "tools",
+            "tool_choice",
+        ]
+
+        supported_params = self.config.get_supported_openai_params("responses/gpt-4.1-mini")
+
+        for param in base_expected_params:
+            assert param in supported_params, f"Expected '{param}' in supported params"
+
+
+class TestGetOptionalParamsIntegration:
+    """Integration tests using litellm.get_optional_params()"""
+
+    def test_user_in_optional_params_for_responses_model(self):
+        """Test that 'user' ends up in optional_params when using responses API models.
+
+        Regression test for: https://github.com/BerriAI/litellm/issues/17633
+        This verifies the full flow through get_optional_params().
+        """
+        from litellm.utils import get_optional_params
+
+        # Test with responses model
+        optional_params = get_optional_params(
+            model="responses/gpt-4.1-mini",
+            custom_llm_provider="openai",
+            user="test-user-123",
+        )
+        assert optional_params.get("user") == "test-user-123"
+
+    def test_user_in_optional_params_for_regular_model(self):
+        """Test that 'user' ends up in optional_params for regular OpenAI models."""
+        from litellm.utils import get_optional_params
+
+        optional_params = get_optional_params(
+            model="gpt-4o",
+            custom_llm_provider="openai",
+            user="test-user-456",
+        )
+        assert optional_params.get("user") == "test-user-456"
+
+    def test_user_param_consistency_between_regular_and_responses(self):
+        """Test that 'user' param behavior is consistent between regular and responses models."""
+        from litellm.utils import get_optional_params
+
+        regular_params = get_optional_params(
+            model="gpt-4.1-mini",
+            custom_llm_provider="openai",
+            user="my-end-user",
+        )
+
+        responses_params = get_optional_params(
+            model="responses/gpt-4.1-mini",
+            custom_llm_provider="openai",
+            user="my-end-user",
+        )
+
+        # Both should include user
+        assert regular_params.get("user") == "my-end-user"
+        assert responses_params.get("user") == "my-end-user"