fix(guardrails): define UnappliableRequestRewrite in the shared guardrail translation utils

The three guardrail translation handlers imported the exception from the proxy policy engine through a function-local import, which CodeQL flagged as a cyclic import. The exception and its helper now live next to the handlers in the shared guardrail translation utils, and the tests import it from there.

The Prompt Security modify-mode helper is also restructured into early-return TypedDict displays so the LIT002 budget stays at its limit

litellm/llms/base_llm/guardrail_translation/utils.py

@@ -413,7 +413,14 @@ def message_with_slot_texts(message: AllMessageValues, texts: Sequence[str]) ->
     return cast("AllMessageValues", rewritten)  # cast-ok: the same row with only its text slots swapped
 
 
-def unappliable_request_rewrite(guardrail_name: str | None) -> Exception:
-    from litellm.proxy.policy_engine.pipeline_executor import UnappliableRequestRewrite
+class UnappliableRequestRewrite(Exception):
+    def __init__(self, guardrail_name: str) -> None:
+        super().__init__(
+            f"Guardrail '{guardrail_name}' rewrote the request in a way this endpoint cannot apply, "
+            "so the request was rejected rather than sent unrewritten"
+        )
+        self.guardrail_name: Final = guardrail_name
 
+
+def unappliable_request_rewrite(guardrail_name: str | None) -> UnappliableRequestRewrite:
     return UnappliableRequestRewrite(guardrail_name or "unknown")

litellm/proxy/guardrails/guardrail_hooks/prompt_security/prompt_security.py

@@ -38,16 +38,27 @@ class PromptSecurityGuardrailMissingSecrets(Exception):
     pass
 
 
+def _inputs_with_structured_messages(
+    inputs: GenericGuardrailAPIInputs, rewritten_messages: Sequence[AllMessageValues] | None
+) -> GenericGuardrailAPIInputs:
+    if rewritten_messages is None:
+        return inputs
+    patched: Final[GenericGuardrailAPIInputs] = {
+        **inputs,
+        "structured_messages": list(rewritten_messages),  # mutable-ok: the TypedDict field is declared as a list
+    }
+    return patched
+
+
 def _inputs_with_modifications(
     inputs: GenericGuardrailAPIInputs,
     modified_texts: list[str],
     rewritten_messages: Sequence[AllMessageValues] | None,
 ) -> GenericGuardrailAPIInputs:
-    texts_patch: Final[GenericGuardrailAPIInputs] = {"texts": modified_texts} if modified_texts else {}
-    messages_patch: Final[GenericGuardrailAPIInputs] = (
-        {"structured_messages": list(rewritten_messages)} if rewritten_messages is not None else {}
-    )
-    return {**inputs, **texts_patch, **messages_patch}
+    if not modified_texts:
+        return _inputs_with_structured_messages(inputs, rewritten_messages)
+    with_texts: Final[GenericGuardrailAPIInputs] = {**inputs, "texts": modified_texts}
+    return _inputs_with_structured_messages(with_texts, rewritten_messages)
 
 
 class _ProtectVerdict(TypedDict, total=False):

litellm/proxy/policy_engine/pipeline_executor.py

@@ -58,15 +58,6 @@ class UndeliverableStreamRewrite(Exception):
         self.guardrail_name: Final = guardrail_name
 
 
-class UnappliableRequestRewrite(Exception):
-    def __init__(self, guardrail_name: str) -> None:
-        super().__init__(
-            f"Guardrail '{guardrail_name}' rewrote the request in a way this endpoint cannot apply, "
-            "so the request was rejected rather than sent unrewritten"
-        )
-        self.guardrail_name: Final = guardrail_name
-
-
 def _tool_call_shape(tool_call: object) -> tuple[object, object]:
     plain: Final = tool_call.model_dump() if isinstance(tool_call, BaseModel) else tool_call
     function: Final = plain.get("function") if isinstance(plain, Mapping) else None

tests/test_litellm/llms/anthropic/chat/guardrail_translation/test_anthropic_guardrail_handler.py

@@ -2296,7 +2296,7 @@ class TestPerMessageTextWriteBack:
 
     @pytest.mark.asyncio
     async def test_one_text_per_row_over_a_system_prompt_is_rejected_by_name(self):
-        from litellm.proxy.policy_engine.pipeline_executor import UnappliableRequestRewrite
+        from litellm.llms.base_llm.guardrail_translation.utils import UnappliableRequestRewrite
 
         data = {
             "model": "claude-sonnet-4-5",

tests/test_litellm/llms/openai/chat/guardrail_translation/test_openai_guardrail_handler.py

@@ -1917,7 +1917,7 @@ class TestPerMessageTextWriteBack:
 
     @pytest.mark.asyncio
     async def test_fewer_texts_than_extracted_over_a_tool_message_is_rejected(self):
-        from litellm.proxy.policy_engine.pipeline_executor import UnappliableRequestRewrite
+        from litellm.llms.base_llm.guardrail_translation.utils import UnappliableRequestRewrite
 
         handler = OpenAIChatCompletionsHandler()
         original_messages = [

tests/test_litellm/llms/openai/responses/test_openai_responses_guardrail_handler.py

@@ -2426,7 +2426,7 @@ class TestPerMessageRewriteWriteBack:
 
     @pytest.mark.asyncio
     async def test_texts_only_per_message_answer_is_rejected_by_name(self):
-        from litellm.proxy.policy_engine.pipeline_executor import UnappliableRequestRewrite
+        from litellm.llms.base_llm.guardrail_translation.utils import UnappliableRequestRewrite
 
         guardrail = _per_message_redactor()
         data = _tool_replay_request()
@@ -2453,7 +2453,7 @@ class TestPerMessageRewriteWriteBack:
 
     @pytest.mark.asyncio
     async def test_texts_only_per_message_answer_over_a_string_input_is_rejected_by_name(self):
-        from litellm.proxy.policy_engine.pipeline_executor import UnappliableRequestRewrite
+        from litellm.llms.base_llm.guardrail_translation.utils import UnappliableRequestRewrite
 
         guardrail = _per_message_redactor()
         data = _string_input_request()

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

@@ -1820,7 +1820,7 @@ async def test_unalignable_rewrite_is_rejected_never_sent_unredacted(
     Skipping the write-back would hand the model the unredacted text, so a
     guardrail could be bypassed by adding ``instructions`` or a tool call.
     """
-    from litellm.proxy.policy_engine.pipeline_executor import UnappliableRequestRewrite
+    from litellm.llms.base_llm.guardrail_translation.utils import UnappliableRequestRewrite
 
     data: dict[str, object] = {"model": "gpt-4o", "input": responses_input}
     if instructions is not None: