From 4468c9fdcb717cb54a6dcd685a14cdec88f6afe9 Mon Sep 17 00:00:00 2001
From: mateo-berri <277851410+mateo-berri@users.noreply.github.com>
Date: Fri, 18 Sep 2026 21:37:01 -0700
Subject: [PATCH] fix(responses): close the reasoning item before announcing
 the message item

---
 .../streaming_iterator.py                     |  6 -----
 .../test_streaming_iterator_transformation.py | 26 +++++++++++++++++++
 2 files changed, 26 insertions(+), 6 deletions(-)

diff --git a/litellm/responses/litellm_completion_transformation/streaming_iterator.py b/litellm/responses/litellm_completion_transformation/streaming_iterator.py
index 0cda83d979d..5173cd04a89 100644
--- a/litellm/responses/litellm_completion_transformation/streaming_iterator.py
+++ b/litellm/responses/litellm_completion_transformation/streaming_iterator.py
@@ -927,12 +927,6 @@ class LiteLLMCompletionStreamingIterator(ResponsesAPIStreamingIterator):
     def _ensure_output_item_for_chunk(self, chunk: ModelResponseStream) -> None:
         # Change: Never return a value, just enqueue output item events
         if self.sent_output_item_added_event:
-            if (
-                not self.sent_message_item_added_event
-                and chunk.choices
-                and self._get_delta_string_from_streaming_choices(chunk.choices)
-            ):
-                self._queue_message_item_added_events()
             return
         if not chunk.choices:
             return
diff --git a/tests/test_litellm/responses/litellm_completion_transformation/test_streaming_iterator_transformation.py b/tests/test_litellm/responses/litellm_completion_transformation/test_streaming_iterator_transformation.py
index 3581771bc63..8fbba0dbf87 100644
--- a/tests/test_litellm/responses/litellm_completion_transformation/test_streaming_iterator_transformation.py
+++ b/tests/test_litellm/responses/litellm_completion_transformation/test_streaming_iterator_transformation.py
@@ -1058,6 +1058,32 @@ async def test_reasoning_then_text_announces_message_item_before_text_events(syn
     assert announced_indexes_by_item_type["message"] != announced_indexes_by_item_type["reasoning"]
 
 
+@pytest.mark.asyncio
+async def test_reasoning_item_closes_before_message_item_opens():
+    iterator: Final = _build_iterator(
+        [
+            _reasoning_chunk("let me think"),
+            _chunk("Hello"),
+            _chunk("!", finish_reason="stop"),
+        ]
+    )
+
+    events: Final = await _collect_events(iterator, sync_mode=False)
+
+    item_lifecycle: Final = [
+        (event.type, event.item.type)
+        for event in events
+        if getattr(event, "type", None)
+        in (ResponsesAPIStreamEvents.OUTPUT_ITEM_ADDED, ResponsesAPIStreamEvents.OUTPUT_ITEM_DONE)
+    ]
+    assert item_lifecycle == [
+        (ResponsesAPIStreamEvents.OUTPUT_ITEM_ADDED, "reasoning"),
+        (ResponsesAPIStreamEvents.OUTPUT_ITEM_DONE, "reasoning"),
+        (ResponsesAPIStreamEvents.OUTPUT_ITEM_ADDED, "message"),
+        (ResponsesAPIStreamEvents.OUTPUT_ITEM_DONE, "message"),
+    ]
+
+
 @pytest.mark.parametrize("sync_mode", [True, False])
 @pytest.mark.asyncio
 async def test_tool_then_reasoning_then_text_gives_message_its_own_output_index(sync_mode: bool):