Merge remote-tracking branch 'origin/main' into litellm_streaming_buffer_release_on_scan

.github/CODEOWNERS

@@ -4,7 +4,7 @@
 /ui/nginx.conf
 /ui/litellm-dashboard/src/lib/http/schema.d.ts
 /ui/litellm-dashboard/tsconfig.tsbuildinfo
-/model_prices_and_context_window.json @mateo-berri
-/litellm/model_prices_and_context_window_backup.json @mateo-berri
+/model_prices_and_context_window.json @mateo-berri @ryan-crabbe-berri @kerry-berri
+/litellm/model_prices_and_context_window_backup.json @mateo-berri @ryan-crabbe-berri @kerry-berri
 /litellm-proxy-extras/litellm_proxy_extras/migrations/ @yuneng-berri @ryan-crabbe-berri
 /.github/CODEOWNERS @yuneng-berri

litellm/responses/litellm_completion_transformation/streaming_iterator.py

@@ -176,6 +176,8 @@ class LiteLLMCompletionStreamingIterator(ResponsesAPIStreamingIterator):
         return {**item_kwargs, "name": tool_name, **namespace_kwargs}
 
     def _is_reasoning_end(self, chunk):
+        if not chunk.choices:
+            return False
         delta: Final = chunk.choices[0].delta
 
         # if this indicates reasoning content, don't consider reasoning ended
@@ -897,6 +899,8 @@ class LiteLLMCompletionStreamingIterator(ResponsesAPIStreamingIterator):
         # Change: Never return a value, just enqueue output item events
         if self.sent_output_item_added_event:
             return
+        if not chunk.choices:
+            return
         delta: Final = chunk.choices[0].delta
 
         self._sequence_number += 1
@@ -1224,6 +1228,8 @@ class LiteLLMCompletionStreamingIterator(ResponsesAPIStreamingIterator):
 
         It's unclear how users expect litellm to translate multiple-choices-per-chunk to the responses API output.
         """
+        if not choices:
+            return ""
         choice: Final = choices[0]
         chat_completion_delta: Final[ChatCompletionDelta] = choice.delta
         return chat_completion_delta.content or ""

tests/test_litellm/responses/litellm_completion_transformation/test_streaming_iterator_transformation.py

@@ -752,6 +752,49 @@ def test_completed_event_restores_usage_hidden_by_stream_options_none():
     assert completed.response.usage.output_tokens == 5
 
 
+def _empty_choices_chunk(usage: Usage | None = None) -> ModelResponseStream:
+    return ModelResponseStream(id=CHAT_COMPLETION_ID, model="claude-haiku-4-5", choices=[], usage=usage)
+
+
+@pytest.mark.asyncio
+async def test_leading_empty_choices_chunk_does_not_kill_the_stream():
+    """
+    Azure leads some streams with a `prompt_filter_results` chunk whose `choices` is empty.
+    The bridge used to index `choices[0]` on it and die before the first token.
+    """
+    iterator = _build_iterator([_empty_choices_chunk(), _chunk("Hello"), _chunk("!", finish_reason="stop")])
+
+    events = [event async for event in iterator]
+
+    event_types = [getattr(event, "type", None) for event in events]
+    assert event_types.count(ResponsesAPIStreamEvents.OUTPUT_ITEM_ADDED) == 1
+    assert "".join(event.delta for event in events if event.type == ResponsesAPIStreamEvents.OUTPUT_TEXT_DELTA) == "Hello!"
+    assert event_types[-1] == ResponsesAPIStreamEvents.RESPONSE_COMPLETED
+
+
+@pytest.mark.asyncio
+async def test_trailing_empty_choices_usage_chunk_reaches_response_completed():
+    """
+    With `stream_options.include_usage` (which the bridge always sets) the last upstream chunk
+    carries only usage and an empty `choices`. It must not crash the stream, and its usage must
+    still land on `response.completed`.
+    """
+    usage: Final = Usage(prompt_tokens=10, completion_tokens=5, total_tokens=15)
+    iterator = _build_iterator([_chunk("Hello"), _chunk("", finish_reason="stop"), _empty_choices_chunk(usage)])
+
+    events = [event async for event in iterator]
+
+    completed = next(
+        event for event in events if getattr(event, "type", None) == ResponsesAPIStreamEvents.RESPONSE_COMPLETED
+    )
+    assert completed.response.usage.input_tokens == 10
+    assert completed.response.usage.output_tokens == 5
+
+
+def test_is_reasoning_end_ignores_empty_choices_chunk():
+    assert _build_iterator([])._is_reasoning_end(_empty_choices_chunk()) is False
+
+
 def test_object_tool_call_arguments_stream_as_valid_json():
     """A provider that sends decoded object arguments must still stream valid JSON.