fix(guardrails): allow native lifecycle logging-only scope

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

litellm/integrations/custom_guardrail.py

@@ -809,7 +809,6 @@ class CustomGuardrail(CustomLogger):
     def supports_logging_only_scope(self) -> bool:
         return (
             self.uses_apply_guardrail_interface()
-            and not self.use_native_lifecycle_hooks
             and type(self).async_logging_hook is CustomGuardrail.async_logging_hook
         )
 

tests/test_litellm/proxy/guardrails/test_guardrail_registry.py

@@ -1,5 +1,5 @@
 from collections.abc import Iterable
-from typing import Final
+from typing import ClassVar, Final
 from unittest.mock import AsyncMock, MagicMock
 
 import pytest
@@ -956,6 +956,10 @@ class _LoggingOnlyScopeUnsupportedGuardrail(_LoggingOnlyScopeSupportedGuardrail)
         return kwargs, result
 
 
+class _LoggingOnlyScopeNativeGuardrail(_LoggingOnlyScopeSupportedGuardrail):
+    use_native_lifecycle_hooks: ClassVar[bool] = True
+
+
 class TestLoggingOnlyScopeValidation:
     def _initialize(
         self,
@@ -968,9 +972,13 @@ class TestLoggingOnlyScopeValidation:
         guardrail_type: Final = "logging_only_scope_test"
 
         def _initializer(litellm_params: LitellmParams, guardrail: Guardrail) -> CustomGuardrail:
+            supported_event_hooks: Final = (
+                [GuardrailEventHooks.logging_only] if callback_type.use_native_lifecycle_hooks else None
+            )
             return callback_type(
                 guardrail_name=guardrail["guardrail_name"],
                 event_hook=litellm_params.mode,
+                supported_event_hooks=supported_event_hooks,
             )
 
         registry_module.guardrail_initializer_registry[guardrail_type] = _initializer
@@ -1041,6 +1049,15 @@ class TestLoggingOnlyScopeValidation:
 
         assert callback.logging_only_scope == "both"
 
+    def test_output_scope_accepted_for_native_lifecycle_guardrail(self) -> None:
+        callback: Final = self._initialize(
+            mode="logging_only",
+            scope="output",
+            callback_type=_LoggingOnlyScopeNativeGuardrail,
+        )
+
+        assert callback.logging_only_scope == "output"
+
     def test_invalid_scope_fails_litellm_params_validation(self) -> None:
         with pytest.raises(ValidationError):
             LitellmParams(guardrail="test", mode="logging_only", logging_only_scope="request")

tests/unit/integrations/test_custom_guardrail.py

@@ -2961,6 +2961,17 @@ class _NativeLifecycleLoggingGuardrail(CustomGuardrail):
         return inputs
 
 
+@pytest.mark.asyncio
+async def test_native_lifecycle_guardrail_logging_only_scope_scans_only_input():
+    guardrail: Final = _NativeLifecycleLoggingGuardrail()
+    guardrail.logging_only_scope = "input"
+    kwargs, response = _logged_call([{"role": "user", "content": "native lifecycle input"}])
+
+    await guardrail.async_logging_hook(kwargs, response, CallTypes.acompletion.value)
+
+    assert guardrail.calls == [("request", ["native lifecycle input"])]
+
+
 @pytest.mark.asyncio
 async def test_native_lifecycle_guardrail_logging_only_scans_assembled_response():
     """A use_native_lifecycle_hooks guardrail accepts mode logging_only and its