From 08b60c409a0b556efb6bbe6470402a4530666870 Mon Sep 17 00:00:00 2001
From: mateo-berri <277851410+mateo-berri@users.noreply.github.com>
Date: Mon, 7 Sep 2026 21:53:26 -0700
Subject: [PATCH] refactor(guardrails): drop the unused
 rewrites_streamed_output hook

Nothing calls it since the streaming pipeline detects rewrites at run time
through the stream observer, so the base method and the content filter's
override were dead code with dead tests
---
 litellm/integrations/custom_guardrail.py      |  3 -
 .../litellm_content_filter/content_filter.py  |  9 ---
 .../content_filter/test_content_filter.py     | 56 -------------------
 3 files changed, 68 deletions(-)

diff --git a/litellm/integrations/custom_guardrail.py b/litellm/integrations/custom_guardrail.py
index 883329c9fa8..2d66a280663 100644
--- a/litellm/integrations/custom_guardrail.py
+++ b/litellm/integrations/custom_guardrail.py
@@ -773,9 +773,6 @@ class CustomGuardrail(CustomLogger):
     def uses_apply_guardrail_interface(self) -> bool:
         return type(self).apply_guardrail is not CustomGuardrail.apply_guardrail
 
-    def rewrites_streamed_output(self) -> bool:
-        return self.mask_response_content
-
     def _deployment_pre_call_target(self) -> "CustomLogger":
         if not self.uses_apply_guardrail_interface() or self.use_native_lifecycle_hooks:
             return self
diff --git a/litellm/proxy/guardrails/guardrail_hooks/litellm_content_filter/content_filter.py b/litellm/proxy/guardrails/guardrail_hooks/litellm_content_filter/content_filter.py
index 85eb50c78e7..722f96ef814 100644
--- a/litellm/proxy/guardrails/guardrail_hooks/litellm_content_filter/content_filter.py
+++ b/litellm/proxy/guardrails/guardrail_hooks/litellm_content_filter/content_filter.py
@@ -1947,15 +1947,6 @@ class ContentFilterGuardrail(CustomGuardrail):
                 exception_str=exception_str,
             )
 
-    def rewrites_streamed_output(self) -> bool:
-        return (
-            super().rewrites_streamed_output()
-            or any(entry["action"] == ContentFilterAction.MASK for entry in self.compiled_patterns)
-            or any(action == ContentFilterAction.MASK for action, _ in self.blocked_words.values())
-            or any(action == ContentFilterAction.MASK for _, _, action in self.category_keywords.values())
-            or any(action == ContentFilterAction.MASK for _, _, action in self.always_block_category_keywords.values())
-        )
-
     async def async_post_call_streaming_iterator_hook(
         self,
         user_api_key_dict: UserAPIKeyAuth,
diff --git a/tests/test_litellm/proxy/guardrails/guardrail_hooks/content_filter/test_content_filter.py b/tests/test_litellm/proxy/guardrails/guardrail_hooks/content_filter/test_content_filter.py
index 73020fe3e6f..be55ac47bde 100644
--- a/tests/test_litellm/proxy/guardrails/guardrail_hooks/content_filter/test_content_filter.py
+++ b/tests/test_litellm/proxy/guardrails/guardrail_hooks/content_filter/test_content_filter.py
@@ -3068,59 +3068,3 @@ class TestContentFilterToolCallArguments:
                 request_data={},
                 input_type="response",
             )
-
-
-class TestRewritesStreamedOutput:
-    def test_block_only_rules_do_not_rewrite(self):
-        guardrail = ContentFilterGuardrail(
-            guardrail_name="cf",
-            patterns=[ContentFilterPattern(pattern_type="prebuilt", pattern_name="us_ssn", action=ContentFilterAction.BLOCK)],
-            blocked_words=[BlockedWord(keyword="kumquat", action=ContentFilterAction.BLOCK)],
-        )
-
-        assert guardrail.rewrites_streamed_output() is False
-
-    def test_mask_blocked_word_rewrites(self):
-        guardrail = ContentFilterGuardrail(
-            guardrail_name="cf",
-            blocked_words=[BlockedWord(keyword="persimmon", action=ContentFilterAction.MASK)],
-        )
-
-        assert guardrail.rewrites_streamed_output() is True
-
-    def test_mask_pattern_rewrites(self):
-        guardrail = ContentFilterGuardrail(
-            guardrail_name="cf",
-            patterns=[ContentFilterPattern(pattern_type="prebuilt", pattern_name="us_ssn", action=ContentFilterAction.MASK)],
-        )
-
-        assert guardrail.rewrites_streamed_output() is True
-
-    def test_mask_response_content_rewrites(self):
-        guardrail = ContentFilterGuardrail(
-            guardrail_name="cf",
-            blocked_words=[BlockedWord(keyword="kumquat", action=ContentFilterAction.BLOCK)],
-            mask_response_content=True,
-        )
-
-        assert guardrail.rewrites_streamed_output() is True
-
-    @pytest.mark.parametrize("action, expected", [("MASK", True), ("BLOCK", False)])
-    def test_category_keywords_follow_the_category_action(self, action, expected):
-        guardrail = ContentFilterGuardrail(
-            guardrail_name="cf",
-            categories=[{"category": "bias_gender", "enabled": True, "action": action}],
-        )
-
-        assert guardrail.category_keywords and not guardrail.always_block_category_keywords
-        assert guardrail.rewrites_streamed_output() is expected
-
-    @pytest.mark.parametrize("action, expected", [("MASK", True), ("BLOCK", False)])
-    def test_always_block_category_keywords_follow_the_category_action(self, action, expected):
-        guardrail = ContentFilterGuardrail(
-            guardrail_name="cf",
-            categories=[{"category": "age_discrimination", "enabled": True, "action": action}],
-        )
-
-        assert guardrail.always_block_category_keywords and not guardrail.category_keywords
-        assert guardrail.rewrites_streamed_output() is expected