From 6a4248cb15600899ccbb6679ea7879887e5349ed Mon Sep 17 00:00:00 2001
From: yucheng-berri <293926326+yucheng-berri@users.noreply.github.com>
Date: Mon, 19 Oct 2026 00:50:19 -0700
Subject: [PATCH] fix(guardrails): skip the empty moderation call when only
 tool or system text is present

---
 .../enterprise_hooks/openai_moderation.py     |  2 +-
 .../guardrails/test_guardrail_coverage.py     | 31 +++++++++++++++++++
 2 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/enterprise/enterprise_hooks/openai_moderation.py b/enterprise/enterprise_hooks/openai_moderation.py
index fdf4d5d2043..74ceaf5d5eb 100644
--- a/enterprise/enterprise_hooks/openai_moderation.py
+++ b/enterprise/enterprise_hooks/openai_moderation.py
@@ -40,7 +40,7 @@ class ENTERPRISE_OpenAI_Moderation(CustomLogger):
         # Covers multimodal list content + Responses-API input. System, instructions
         # and tool text go in a second call after the message text.
         message_text, added_text = split_message_text(data)
-        texts = ("".join(message_text), "".join(added_text)) if added_text else ("".join(message_text),)
+        texts = tuple(text for text in ("".join(message_text), "".join(added_text)) if text) or ("",)
 
         from litellm.proxy.proxy_server import llm_router
 
diff --git a/tests/unit/proxy/guardrails/test_guardrail_coverage.py b/tests/unit/proxy/guardrails/test_guardrail_coverage.py
index fc9146d6acd..5cb46491d0e 100644
--- a/tests/unit/proxy/guardrails/test_guardrail_coverage.py
+++ b/tests/unit/proxy/guardrails/test_guardrail_coverage.py
@@ -907,6 +907,37 @@ async def test_openai_moderation_sends_tool_and_system_text_in_its_own_call(
     assert seen == ["say hi", added]
 
 
+@pytest.mark.asyncio
+@pytest.mark.parametrize(
+    ("data", "inputs"),
+    [
+        ({"messages": [{"role": "user", "content": [{"type": "image_url", "image_url": {"url": "x"}}]}]}, [""]),
+        (
+            {
+                "system": "be brief",
+                "messages": [{"role": "user", "content": [{"type": "image_url", "image_url": {"url": "x"}}]}],
+            },
+            ["be brief"],
+        ),
+    ],
+    ids=("no-text", "system-only"),
+)
+async def test_openai_moderation_makes_one_call_when_one_side_has_no_text(
+    monkeypatch: pytest.MonkeyPatch, user_api_key: UserAPIKeyAuth, data: dict[str, JsonValue], inputs: list[str]
+) -> None:
+    from enterprise.enterprise_hooks.openai_moderation import ENTERPRISE_OpenAI_Moderation
+
+    seen: Final[list[str]] = []
+
+    async def amoderation(model: str, input: str) -> SimpleNamespace:
+        seen.append(input)
+        return SimpleNamespace(results=[SimpleNamespace(flagged=False)])
+
+    monkeypatch.setattr("litellm.proxy.proxy_server.llm_router", SimpleNamespace(amoderation=amoderation))
+    assert await ENTERPRISE_OpenAI_Moderation().async_moderation_hook(data, user_api_key, "acompletion") is None
+    assert seen == inputs
+
+
 @pytest.mark.asyncio
 @pytest.mark.parametrize(
     ("configured_after_init", "expected_model"),