fix(proxy): persist guardrail info in spend logs for /v1/responses

Pre-call guardrail blocks on /v1/responses wrote guardrail_information
as null in LiteLLM_SpendLogs because _handle_logging_proxy_only_error
splits request_data by LoggedLiteLLMParams keys and litellm_metadata,
where the Responses API stores request metadata including
standard_logging_guardrail_information, was not among them. It fell
into optional_params, so merge_litellm_metadata never saw it. Add
litellm_metadata to LoggedLiteLLMParams so it routes into
litellm_params the same way metadata does on the chat completions path

Fixes #28971.

litellm/types/utils.py

@@ -2486,6 +2486,7 @@ class LoggedLiteLLMParams(TypedDict, total=False):
     litellm_call_id: Optional[str]
     model_alias_map: Optional[dict]
     metadata: Optional[dict]
+    litellm_metadata: Optional[dict]
     model_info: Optional[dict]
     proxy_server_request: Optional[dict]
     acompletion: Optional[bool]

tests/test_litellm/proxy/test_proxy_utils.py

@@ -118,6 +118,63 @@ async def test_proxy_only_error_log_marks_no_upstream_llm_call():
     assert captured.get("flag") is True
 
 
+@pytest.mark.asyncio
+async def test_proxy_only_error_log_keeps_litellm_metadata_in_litellm_params():
+    """Responses API requests carry guardrail info under ``litellm_metadata``
+    (not ``metadata``). It must land in litellm_params so
+    ``merge_litellm_metadata`` can surface ``guardrail_information`` in the
+    spend-log failure row, matching the chat completions path."""
+    from litellm.proxy._types import UserAPIKeyAuth
+
+    proxy_logging_obj = ProxyLogging(user_api_key_cache=DualCache())
+    captured = {}
+    guardrail_info = [{"guardrail_name": "test-guard", "guardrail_status": "blocked"}]
+
+    def fake_update_environment_variables(self, *args, **kwargs):
+        captured["litellm_params"] = kwargs.get("litellm_params")
+        captured["optional_params"] = kwargs.get("optional_params")
+
+    from litellm.litellm_core_utils.litellm_logging import Logging
+
+    orig_update_env = Logging.update_environment_variables
+    orig_pre_call = Logging.pre_call
+    orig_async_failure = Logging.async_failure_handler
+
+    async def _noop_async_failure(self, *args, **kwargs):
+        return None
+
+    Logging.update_environment_variables = fake_update_environment_variables
+    Logging.pre_call = lambda self, *args, **kwargs: None
+    Logging.async_failure_handler = _noop_async_failure
+    try:
+        await proxy_logging_obj._handle_logging_proxy_only_error(
+            request_data={
+                "model": "gpt-4o",
+                "input": "blocked prompt",
+                "litellm_metadata": {
+                    "standard_logging_guardrail_information": guardrail_info
+                },
+            },
+            user_api_key_dict=UserAPIKeyAuth(
+                api_key="sk-1234", request_route="/v1/responses"
+            ),
+            route="/v1/responses",
+            original_exception=HTTPException(status_code=400, detail="blocked"),
+        )
+    finally:
+        Logging.update_environment_variables = orig_update_env
+        Logging.pre_call = orig_pre_call
+        Logging.async_failure_handler = orig_async_failure
+
+    assert (
+        captured["litellm_params"]["litellm_metadata"][
+            "standard_logging_guardrail_information"
+        ]
+        == guardrail_info
+    )
+    assert "litellm_metadata" not in captured["optional_params"]
+
+
 def test_get_model_group_info_order():
     from litellm import Router
     from litellm.proxy.proxy_server import _get_model_group_info