diff --git a/tests/litellm/llms/test_openai_get_models_url.py b/tests/litellm/llms/test_openai_get_models_url.py
index 0bce0e46fc2..21b84e57aaa 100644
--- a/tests/litellm/llms/test_openai_get_models_url.py
+++ b/tests/litellm/llms/test_openai_get_models_url.py
@@ -51,3 +51,37 @@ class TestGetModelsUrl:
     def test_localhost_without_v1(self):
         """Localhost with port but no /v1 should get /v1/models appended."""
         assert self._get_url_for_api_base("http://localhost:11434") == "http://localhost:11434/v1/models"
+
+    def test_default_api_base(self):
+        """If api_base is None, it should default to OpenAI and append /v1/models."""
+        mock_response = MagicMock()
+        mock_response.status_code = 200
+        mock_response.json.return_value = {"data": []}
+
+        with patch("litellm.module_level_client.get", return_value=mock_response) as mock_get:
+            OpenAIGPTConfig().get_models(api_key="fake-key", api_base=None)
+            assert mock_get.call_args.kwargs["url"] == "https://api.openai.com/v1/models"
+
+    @patch("litellm.llms.openai.chat.gpt_transformation.get_secret_str", return_value="default-key")
+    def test_default_api_key(self, mock_get_secret):
+        """If api_key is None, it should fetch from secrets."""
+        mock_response = MagicMock()
+        mock_response.status_code = 200
+        mock_response.json.return_value = {"data": []}
+
+        with patch("litellm.module_level_client.get", return_value=mock_response) as mock_get:
+            OpenAIGPTConfig().get_models(api_key=None, api_base="https://example.com")
+            assert mock_get.call_args.kwargs["url"] == "https://example.com/v1/models"
+            assert mock_get.call_args.kwargs["headers"]["Authorization"] == "Bearer default-key"
+
+    def test_get_models_error(self):
+        """If the API returns an error, get_models should raise an exception."""
+        mock_response = MagicMock()
+        mock_response.status_code = 400
+        mock_response.text = "Error message"
+
+        import pytest
+        with patch("litellm.module_level_client.get", return_value=mock_response):
+            with pytest.raises(Exception) as exc:
+                OpenAIGPTConfig().get_models(api_key="fake-key", api_base="https://example.com")
+            assert "Failed to get models: Error message" in str(exc.value)