diff --git a/examples/basic/usage_tracking.py b/examples/basic/usage_tracking.py
index 30000b010..fd5a717c2 100644
--- a/examples/basic/usage_tracking.py
+++ b/examples/basic/usage_tracking.py
@@ -43,4 +43,3 @@ async def main() -> None:
 
 if __name__ == "__main__":
     asyncio.run(main())
-
diff --git a/examples/model_providers/litellm_auto.py b/examples/model_providers/litellm_auto.py
index 5e6942713..c9ab359d3 100644
--- a/examples/model_providers/litellm_auto.py
+++ b/examples/model_providers/litellm_auto.py
@@ -15,11 +15,13 @@
 # import logging
 # logging.basicConfig(level=logging.DEBUG)
 
+
 @function_tool
 def get_weather(city: str):
     print(f"[debug] getting weather for {city}")
     return f"The weather in {city} is sunny."
 
+
 class Result(BaseModel):
     output_text: str
     tool_results: list[str]
diff --git a/examples/realtime/app/server.py b/examples/realtime/app/server.py
index d4ff47e80..abdb1dabb 100644
--- a/examples/realtime/app/server.py
+++ b/examples/realtime/app/server.py
@@ -198,9 +198,7 @@ async def websocket_endpoint(websocket: WebSocket, session_id: str):
                                 {"type": "input_text", "text": prompt_text},
                             ]
                             if prompt_text
-                            else [
-                                {"type": "input_image", "image_url": data_url, "detail": "high"}
-                            ]
+                            else [{"type": "input_image", "image_url": data_url, "detail": "high"}]
                         ),
                     }
                     await manager.send_user_message(session_id, user_msg)
@@ -271,7 +269,11 @@ async def websocket_endpoint(websocket: WebSocket, session_id: str):
                             "role": "user",
                             "content": (
                                 [
-                                    {"type": "input_image", "image_url": data_url, "detail": "high"},
+                                    {
+                                        "type": "input_image",
+                                        "image_url": data_url,
+                                        "detail": "high",
+                                    },
                                     {"type": "input_text", "text": prompt_text},
                                 ]
                                 if prompt_text
diff --git a/examples/realtime/cli/demo.py b/examples/realtime/cli/demo.py
index 63bbd2099..4dfaf2c5a 100644
--- a/examples/realtime/cli/demo.py
+++ b/examples/realtime/cli/demo.py
@@ -23,8 +23,8 @@
 FORMAT = np.int16
 CHANNELS = 1
 ENERGY_THRESHOLD = 0.015  # RMS threshold for barge‑in while assistant is speaking
-PREBUFFER_CHUNKS = 3      # initial jitter buffer (~120ms with 40ms chunks)
-FADE_OUT_MS = 12          # short fade to avoid clicks when interrupting
+PREBUFFER_CHUNKS = 3  # initial jitter buffer (~120ms with 40ms chunks)
+FADE_OUT_MS = 12  # short fade to avoid clicks when interrupting
 
 # Set up logging for OpenAI agents SDK
 # logging.basicConfig(
@@ -108,14 +108,18 @@ def _output_callback(self, outdata, frames: int, time, status) -> None:
 
             samples, item_id, content_index = self.current_audio_chunk
             samples_filled = 0
-            while samples_filled < len(outdata) and self.fade_done_samples < self.fade_total_samples:
+            while (
+                samples_filled < len(outdata) and self.fade_done_samples < self.fade_total_samples
+            ):
                 remaining_output = len(outdata) - samples_filled
                 remaining_fade = self.fade_total_samples - self.fade_done_samples
                 n = min(remaining_output, remaining_fade)
 
                 src = samples[self.chunk_position : self.chunk_position + n].astype(np.float32)
                 # Linear ramp from current level down to 0 across remaining fade samples
-                idx = np.arange(self.fade_done_samples, self.fade_done_samples + n, dtype=np.float32)
+                idx = np.arange(
+                    self.fade_done_samples, self.fade_done_samples + n, dtype=np.float32
+                )
                 gain = 1.0 - (idx / float(self.fade_total_samples))
                 ramped = np.clip(src * gain, -32768.0, 32767.0).astype(np.int16)
                 outdata[samples_filled : samples_filled + n, 0] = ramped
@@ -155,7 +159,10 @@ def _output_callback(self, outdata, frames: int, time, status) -> None:
             if self.current_audio_chunk is None:
                 try:
                     # Respect a small jitter buffer before starting playback
-                    if self.prebuffering and self.output_queue.qsize() < self.prebuffer_target_chunks:
+                    if (
+                        self.prebuffering
+                        and self.output_queue.qsize() < self.prebuffer_target_chunks
+                    ):
                         break
                     self.prebuffering = False
                     self.current_audio_chunk = self.output_queue.get_nowait()
diff --git a/src/agents/extensions/memory/__init__.py b/src/agents/extensions/memory/__init__.py
index 8b344fc1b..13fa36e75 100644
--- a/src/agents/extensions/memory/__init__.py
+++ b/src/agents/extensions/memory/__init__.py
@@ -1,4 +1,3 @@
-
 """Session memory backends living in the extensions namespace.
 
 This package contains optional, production-grade session implementations that
@@ -6,6 +5,7 @@
 conform to the :class:`agents.memory.session.Session` protocol so they can be
 used as a drop-in replacement for :class:`agents.memory.session.SQLiteSession`.
 """
+
 from __future__ import annotations
 
 from .sqlalchemy_session import SQLAlchemySession  # noqa: F401
diff --git a/src/agents/extensions/models/litellm_model.py b/src/agents/extensions/models/litellm_model.py
index f13793ac9..4369b342b 100644
--- a/src/agents/extensions/models/litellm_model.py
+++ b/src/agents/extensions/models/litellm_model.py
@@ -413,9 +413,9 @@ def convert_message_to_openai(
                 else:
                     # Convert object to dict by accessing its attributes
                     block_dict: dict[str, Any] = {}
-                    if hasattr(block, '__dict__'):
+                    if hasattr(block, "__dict__"):
                         block_dict = dict(block.__dict__.items())
-                    elif hasattr(block, 'model_dump'):
+                    elif hasattr(block, "model_dump"):
                         block_dict = block.model_dump()
                     else:
                         # Last resort: convert to string representation
diff --git a/src/agents/models/chatcmpl_converter.py b/src/agents/models/chatcmpl_converter.py
index 1c9f826de..77ff22ee0 100644
--- a/src/agents/models/chatcmpl_converter.py
+++ b/src/agents/models/chatcmpl_converter.py
@@ -106,6 +106,7 @@ def message_to_output_items(cls, message: ChatCompletionMessage) -> list[TRespon
                 # Store thinking blocks in the reasoning item's content
                 # Convert thinking blocks to Content objects
                 from openai.types.responses.response_reasoning_item import Content
+
                 reasoning_item.content = [
                     Content(text=str(block.get("thinking", "")), type="reasoning_text")
                     for block in message.thinking_blocks
@@ -282,9 +283,7 @@ def extract_all_content(
                         f"Only file_data is supported for input_file {casted_file_param}"
                     )
                 if "filename" not in casted_file_param or not casted_file_param["filename"]:
-                    raise UserError(
-                        f"filename must be provided for input_file {casted_file_param}"
-                    )
+                    raise UserError(f"filename must be provided for input_file {casted_file_param}")
                 out.append(
                     File(
                         type="file",
diff --git a/src/agents/realtime/model_events.py b/src/agents/realtime/model_events.py
index a6d0bdecb..7c839aa18 100644
--- a/src/agents/realtime/model_events.py
+++ b/src/agents/realtime/model_events.py
@@ -84,6 +84,7 @@ class RealtimeModelInputAudioTranscriptionCompletedEvent:
 
     type: Literal["input_audio_transcription_completed"] = "input_audio_transcription_completed"
 
+
 @dataclass
 class RealtimeModelInputAudioTimeoutTriggeredEvent:
     """Input audio timeout triggered."""
@@ -94,6 +95,7 @@ class RealtimeModelInputAudioTimeoutTriggeredEvent:
 
     type: Literal["input_audio_timeout_triggered"] = "input_audio_timeout_triggered"
 
+
 @dataclass
 class RealtimeModelTranscriptDeltaEvent:
     """Partial transcript update."""
diff --git a/src/agents/result.py b/src/agents/result.py
index 5cf0e74c8..9d57da13d 100644
--- a/src/agents/result.py
+++ b/src/agents/result.py
@@ -201,7 +201,11 @@ async def stream_events(self) -> AsyncIterator[StreamEvent]:
                 break
 
             if isinstance(item, QueueCompleteSentinel):
+                # Await input guardrails if they are still running, so late exceptions are captured.
+                await self._await_task_safely(self._input_guardrails_task)
+
                 self._event_queue.task_done()
+
                 # Check for errors, in case the queue was completed due to an exception
                 self._check_errors()
                 break
@@ -274,3 +278,19 @@ def _cleanup_tasks(self):
 
     def __str__(self) -> str:
         return pretty_print_run_result_streaming(self)
+
+    async def _await_task_safely(self, task: asyncio.Task[Any] | None) -> None:
+        """Await a task if present, ignoring cancellation and storing exceptions elsewhere.
+
+        This ensures we do not lose late guardrail exceptions while not surfacing
+        CancelledError to callers of stream_events.
+        """
+        if task and not task.done():
+            try:
+                await task
+            except asyncio.CancelledError:
+                # Task was cancelled (e.g., due to result.cancel()). Nothing to do here.
+                pass
+            except Exception:
+                # The exception will be surfaced via _check_errors() if needed.
+                pass
diff --git a/src/agents/run.py b/src/agents/run.py
index 5056758fb..1027b2355 100644
--- a/src/agents/run.py
+++ b/src/agents/run.py
@@ -1127,14 +1127,11 @@ async def _run_single_turn_streamed(
 
         # Filter out HandoffCallItem to avoid duplicates (already sent earlier)
         items_to_filter = [
-            item for item in items_to_filter
-            if not isinstance(item, HandoffCallItem)
+            item for item in items_to_filter if not isinstance(item, HandoffCallItem)
         ]
 
         # Create filtered result and send to queue
-        filtered_result = _dc.replace(
-            single_step_result, new_step_items=items_to_filter
-        )
+        filtered_result = _dc.replace(single_step_result, new_step_items=items_to_filter)
         RunImpl.stream_step_result_to_queue(filtered_result, streamed_result._event_queue)
         return single_step_result
 
@@ -1235,8 +1232,7 @@ async def _get_single_step_result_from_response(
         # Send handoff items immediately for streaming, but avoid duplicates
         if event_queue is not None and processed_response.new_items:
             handoff_items = [
-                item for item in processed_response.new_items
-                if isinstance(item, HandoffCallItem)
+                item for item in processed_response.new_items if isinstance(item, HandoffCallItem)
             ]
             if handoff_items:
                 RunImpl.stream_step_items_to_queue(cast(list[RunItem], handoff_items), event_queue)
diff --git a/tests/test_agent_instructions_signature.py b/tests/test_agent_instructions_signature.py
index bd16f9f57..604eb5189 100644
--- a/tests/test_agent_instructions_signature.py
+++ b/tests/test_agent_instructions_signature.py
@@ -16,6 +16,7 @@ def mock_run_context(self):
     @pytest.mark.asyncio
     async def test_valid_async_signature_passes(self, mock_run_context):
         """Test that async function with correct signature works"""
+
         async def valid_instructions(context, agent):
             return "Valid async instructions"
 
@@ -26,6 +27,7 @@ async def valid_instructions(context, agent):
     @pytest.mark.asyncio
     async def test_valid_sync_signature_passes(self, mock_run_context):
         """Test that sync function with correct signature works"""
+
         def valid_instructions(context, agent):
             return "Valid sync instructions"
 
@@ -36,6 +38,7 @@ def valid_instructions(context, agent):
     @pytest.mark.asyncio
     async def test_one_parameter_raises_error(self, mock_run_context):
         """Test that function with only one parameter raises TypeError"""
+
         def invalid_instructions(context):
             return "Should fail"
 
@@ -50,6 +53,7 @@ def invalid_instructions(context):
     @pytest.mark.asyncio
     async def test_three_parameters_raises_error(self, mock_run_context):
         """Test that function with three parameters raises TypeError"""
+
         def invalid_instructions(context, agent, extra):
             return "Should fail"
 
@@ -64,6 +68,7 @@ def invalid_instructions(context, agent, extra):
     @pytest.mark.asyncio
     async def test_zero_parameters_raises_error(self, mock_run_context):
         """Test that function with no parameters raises TypeError"""
+
         def invalid_instructions():
             return "Should fail"
 
@@ -78,6 +83,7 @@ def invalid_instructions():
     @pytest.mark.asyncio
     async def test_function_with_args_kwargs_fails(self, mock_run_context):
         """Test that function with *args/**kwargs fails validation"""
+
         def flexible_instructions(context, agent, *args, **kwargs):
             return "Flexible instructions"
 
diff --git a/tests/test_agent_runner_streamed.py b/tests/test_agent_runner_streamed.py
index ff807ca96..90071a3d7 100644
--- a/tests/test_agent_runner_streamed.py
+++ b/tests/test_agent_runner_streamed.py
@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+import asyncio
 import json
 from typing import Any
 
@@ -523,6 +524,35 @@ def guardrail_function(
             pass
 
 
+@pytest.mark.asyncio
+async def test_slow_input_guardrail_still_raises_exception_streamed():
+    async def guardrail_function(
+        context: RunContextWrapper[Any], agent: Agent[Any], input: Any
+    ) -> GuardrailFunctionOutput:
+        # Simulate a slow guardrail that completes after model streaming ends.
+        await asyncio.sleep(0.05)
+        return GuardrailFunctionOutput(
+            output_info=None,
+            tripwire_triggered=True,
+        )
+
+    model = FakeModel()
+    # Ensure the model finishes streaming quickly.
+    model.set_next_output([get_text_message("ok")])
+
+    agent = Agent(
+        name="test",
+        input_guardrails=[InputGuardrail(guardrail_function=guardrail_function)],
+        model=model,
+    )
+
+    # Even though the guardrail is slower than the model stream, the exception should still raise.
+    with pytest.raises(InputGuardrailTripwireTriggered):
+        result = Runner.run_streamed(agent, input="user_message")
+        async for _ in result.stream_events():
+            pass
+
+
 @pytest.mark.asyncio
 async def test_output_guardrail_tripwire_triggered_causes_exception_streamed():
     def guardrail_function(
diff --git a/tests/test_session.py b/tests/test_session.py
index 5e96d3f25..40c0dc779 100644
--- a/tests/test_session.py
+++ b/tests/test_session.py
@@ -445,6 +445,7 @@ def filter_assistant_messages(history, new_input):
         assert len(model.last_turn_args["input"]) == 2
         assert model.last_turn_args["input"] == expected_model_input
 
+
 @pytest.mark.asyncio
 async def test_sqlite_session_unicode_content():
     """Test that session correctly stores and retrieves unicode/non-ASCII content."""