diff --git a/litellm/proxy/guardrails/guardrail_hooks/singulr/singulr.py b/litellm/proxy/guardrails/guardrail_hooks/singulr/singulr.py
index 9bb5efd1844..1400ce1cef8 100644
--- a/litellm/proxy/guardrails/guardrail_hooks/singulr/singulr.py
+++ b/litellm/proxy/guardrails/guardrail_hooks/singulr/singulr.py
@@ -82,7 +82,6 @@ class SingulrGuardrail(CustomGuardrail):
         if "supported_event_hooks" not in kwargs:
             kwargs["supported_event_hooks"] = [
                 GuardrailEventHooks.pre_call,
-                GuardrailEventHooks.post_call,
             ]
 
         super().__init__(**kwargs)
@@ -98,7 +97,7 @@ class SingulrGuardrail(CustomGuardrail):
     def _build_payload(
         self,
         request_data: dict[str, Any],
-        input_type: Literal["request", "response"],
+        input_type: str,
     ) -> dict[str, Any]:
         request = SingulrGuardrailRequest.model_validate(request_data)
         if not request.model_dump(exclude_none=True):
@@ -178,7 +177,7 @@ class SingulrGuardrail(CustomGuardrail):
         self,
         inputs: GenericGuardrailAPIInputs,
         request_data: dict,
-        input_type: Literal["request", "response"],
+        input_type: str,
         logging_obj: Optional["LiteLLMLoggingObj"] = None,
     ) -> GenericGuardrailAPIInputs:
         payload = self._build_payload(cast(dict[str, Any], request_data), input_type)
diff --git a/litellm/types/proxy/guardrails/guardrail_hooks/singulr.py b/litellm/types/proxy/guardrails/guardrail_hooks/singulr.py
index 74de6017176..b5324a58def 100644
--- a/litellm/types/proxy/guardrails/guardrail_hooks/singulr.py
+++ b/litellm/types/proxy/guardrails/guardrail_hooks/singulr.py
@@ -39,7 +39,7 @@ class SingulrGuardrailPayload(BaseModel):
     """Payload sent to the Singulr guardrail API."""
 
     request: SingulrGuardrailRequest
-    input_type: Literal["request", "response"]
+    input_type: str
 
 
 class SingulrGuardrailConfigModel(GuardrailConfigModel):
diff --git a/tests/test_litellm/proxy/guardrails/guardrail_hooks/test_singulr.py b/tests/test_litellm/proxy/guardrails/guardrail_hooks/test_singulr.py
index 2243cae1e3b..c30105d8aa3 100644
--- a/tests/test_litellm/proxy/guardrails/guardrail_hooks/test_singulr.py
+++ b/tests/test_litellm/proxy/guardrails/guardrail_hooks/test_singulr.py
@@ -11,6 +11,7 @@ import pytest
 
 from litellm.exceptions import GuardrailRaisedException
 from litellm.proxy.guardrails.guardrail_hooks.singulr.singulr import SingulrGuardrail
+from litellm.types.guardrails import GuardrailEventHooks
 from litellm.types.proxy.guardrails.guardrail_hooks.singulr import (
     SingulrGuardrailConfigModel,
 )
@@ -104,6 +105,13 @@ class TestSingulrConfiguration:
             SingulrGuardrail(api_key="test_key", api_base="https://remote.singulr.ai")
             mock_logger.warning.assert_not_called()
 
+    def test_only_supports_pre_call_hook(self):
+        """Singulr only forwards the original request; there is no response
+        text available to scan on the post_call path, so post_call must not
+        be registered as a supported event hook."""
+        guardrail = SingulrGuardrail(api_key="test_key")
+        assert guardrail.supported_event_hooks == [GuardrailEventHooks.pre_call]
+
 
 # ---------------------------------------------------------------------------
 # Allow decision
@@ -314,18 +322,6 @@ class TestSingulrBuildPayload:
     def test_empty_request_returns_empty_payload(self, singulr_guardrail):
         assert singulr_guardrail._build_payload({}, "request") == {}
 
-    def test_response_input_type_forwards_request_messages(self, singulr_guardrail):
-        """input_type="response" currently forwards the same request payload
-        shape as input_type="request" -- no separate response body is sent."""
-        request_data = {"messages": [{"role": "user", "content": "hi"}]}
-        payload = singulr_guardrail._build_payload(request_data, "response")
-        assert payload["input_type"] == "response"
-        assert payload["request"]["messages"] == [{"role": "user", "content": "hi"}]
-        assert "response" not in payload
-
-    def test_response_returns_empty_payload_when_no_messages(self, singulr_guardrail):
-        assert singulr_guardrail._build_payload({}, "response") == {}
-
 
 # ---------------------------------------------------------------------------
 # Tool definition scanning