From b1508161ecb5bd2695fb677101cca8755d489bcd Mon Sep 17 00:00:00 2001
From: Cursor Agent <cursoragent@cursor.com>
Date: Mon, 11 May 2026 15:25:40 +0000
Subject: [PATCH] Preserve reasoning summary without effort

---
 litellm/main.py                 |  2 ++
 tests/test_litellm/test_main.py | 24 ++++++++++++++++++++++++
 2 files changed, 26 insertions(+)

diff --git a/litellm/main.py b/litellm/main.py
index c324f982b8..29a9ffc84f 100644
--- a/litellm/main.py
+++ b/litellm/main.py
@@ -1684,6 +1684,8 @@ def completion(  # type: ignore # noqa: PLR0915
                         "effort": eff,
                         "summary": rs_val,
                     }
+                else:
+                    optional_params["reasoning_effort"] = {"summary": rs_val}
 
             return responses_api_bridge.completion(
                 model=model,
diff --git a/tests/test_litellm/test_main.py b/tests/test_litellm/test_main.py
index c37f9fc26b..76336a91fc 100644
--- a/tests/test_litellm/test_main.py
+++ b/tests/test_litellm/test_main.py
@@ -875,6 +875,30 @@ def test_gpt_5_4_responses_bridge_merges_reasoning_summary_kwarg_without_tools(
     assert "reasoning_summary" not in optional_params
 
 
+@patch("litellm.completion_extras.responses_api_bridge.completion")
+def test_responses_bridge_preserves_reasoning_summary_without_effort(
+    mock_responses_completion,
+):
+    """Reasoning summary should survive responses routing even without effort."""
+    mock_responses_completion.return_value = MagicMock()
+
+    import litellm
+
+    with patch.object(litellm, "route_all_chat_openai_to_responses", True):
+        litellm.completion(
+            model="gpt-4o",
+            messages=[{"role": "user", "content": "ok"}],
+            reasoningSummary="auto",
+            api_key="fake-key",
+        )
+
+    assert mock_responses_completion.called is True
+    optional_params = mock_responses_completion.call_args.kwargs["optional_params"]
+    assert optional_params["reasoning_effort"] == {"summary": "auto"}
+    assert "reasoningSummary" not in optional_params
+    assert "reasoning_summary" not in optional_params
+
+
 @patch("litellm.completion_extras.responses_api_bridge.completion")
 def test_gpt_5_responses_bridge_tools_and_reasoning_summary(
     mock_responses_completion,