fix(headroom): fake-stream converted sync /v1/responses calls too

The sync response_api_handler agentic branch returned the completed ResponsesAPIResponse for a request the Headroom guardrail had converted from streaming, so litellm.responses(stream=True) handed callers a non-iterable object. Wrap it in the same fake stream the async path uses

litellm/llms/custom_httpx/llm_http_handler.py

@@ -2744,6 +2744,7 @@ class BaseLLMHTTPHandler:
         )
 
         if self._has_agentic_completion_hook(logging_obj):
+            agentic_kwargs: Final = dict(litellm_params)
             final_response: Final = run_async_function(
                 self._call_agentic_completion_hooks,
                 response=initial_response,
@@ -2754,10 +2755,19 @@ class BaseLLMHTTPHandler:
                 logging_obj=logging_obj,
                 stream=False,
                 custom_llm_provider=custom_llm_provider,
-                kwargs=dict(litellm_params),
+                kwargs=agentic_kwargs,
                 api_surface="responses",
             )
-            return final_response if final_response is not None else initial_response
+            result: Final = final_response if final_response is not None else initial_response
+            if converted_stream_requested(agentic_kwargs) and not agentic_kwargs.get("_agentic_loop_depth"):
+                return self._wrap_responses_response_as_fake_stream(
+                    result=result,
+                    model=model,
+                    responses_api_provider_config=responses_api_provider_config,
+                    logging_obj=logging_obj,
+                    custom_llm_provider=custom_llm_provider,
+                )
+            return result
 
         return initial_response
 

tests/test_litellm/proxy/guardrails/guardrail_hooks/test_headroom.py

@@ -2241,6 +2241,58 @@ async def test_streaming_responses_resolves_ccr_retrieval_end_to_end(
     assert not any(key.startswith("_headroom_interception") for key in followup_body)
 
 
+def test_sync_streaming_responses_resolves_ccr_retrieval_end_to_end(
+    guardrail: HeadroomGuardrail,
+    respx_mock: respx.MockRouter,
+    monkeypatch: pytest.MonkeyPatch,
+):
+    """The synchronous responses() path converts the stream the same way, so it
+    must hand back a stream iterator with the resolved answer rather than the
+    completed response object."""
+    original_content = "the full uncompressed document"
+    final_answer = "the document says hello"
+    guardrail._issued_hashes_by_call_id["ccr-call-id"] = (
+        frozenset({CCR_HASH}),
+        time.monotonic() + 999,
+    )
+
+    monkeypatch.setenv("OPENAI_API_KEY", "sk-test")
+    monkeypatch.setattr(litellm, "disable_aiohttp_transport", True)
+    monkeypatch.setattr(litellm, "callbacks", [guardrail])
+    upstream = respx_mock.post("https://api.openai.com/v1/responses").mock(
+        side_effect=[
+            httpx.Response(200, json=_openai_responses_retrieve_call_payload()),
+            httpx.Response(200, json=_openai_responses_text_payload(final_answer)),
+        ]
+    )
+
+    with patch.object(
+        guardrail.async_handler,
+        "get",
+        new_callable=AsyncMock,
+        return_value=_make_retrieve_response(original_content),
+    ) as mock_get:
+        response = litellm.responses(
+            model="openai/gpt-4o",
+            input=[{"role": "user", "content": f"summarize hash={CCR_HASH}"}],
+            tools=[_responses_retrieve_tool_definition()],
+            stream=True,
+            litellm_call_id="ccr-call-id",
+        )
+        events = list(response)
+
+    streamed_text = "".join(
+        getattr(event, "delta", "") for event in events if getattr(event, "type", None) == "response.output_text.delta"
+    )
+    assert streamed_text == final_answer
+    assert not any(
+        getattr(getattr(event, "item", None), "type", None) == "function_call" for event in events
+    )
+    mock_get.assert_called_once()
+    assert len(upstream.calls) == 2
+    assert not json.loads(upstream.calls[1].request.content).get("stream")
+
+
 # ---------------------------------------------------------------------------
 # LIT-5018: the turn the model is being asked to act on is never compressed.
 #