fix(websearch): strip Claude Code instructional prefix in short-circuit search

Signed-off-by: agustin18 <agustinsaiz02@gmail.com>

litellm/integrations/websearch_interception/handler.py

@@ -8,6 +8,7 @@ server-side using litellm router's search tools.
 
 import asyncio
 import math
+import re
 import uuid
 from collections.abc import AsyncIterator, Mapping, Sequence
 from dataclasses import dataclass
@@ -92,6 +93,11 @@ WEBSEARCH_NATIVE_BLOCKS_METADATA_KEY: Final = "websearch_native_blocks"
 
 _RESPONSE_CONTENT_FIELD: Final = "content"
 
+_CLAUDE_CODE_SEARCH_PREFIX_RE: Final = re.compile(
+    r"^\s*(?:Perform\s+a\s+)?(?:web\s+)?search\s+for\s+(?:the\s+)?query:\s*",
+    re.IGNORECASE,
+)
+
 _ResponseT: Final = TypeVar("_ResponseT")
 
 
@@ -288,6 +294,20 @@ class WebSearchInterceptionLogger(CustomLogger):
         """
         return validated_max_agentic_loops(max_agentic_loops, field="websearch_interception_params.max_agentic_loops")
 
+    @classmethod
+    def _extract_short_circuit_query(cls, raw_message: str) -> str:
+        """Extract the intended search terms from a short-circuit user message.
+
+        Clients such as Claude Code format standalone WebSearch requests with an
+        instructional wrapper (e.g. 'Perform a web search for the query: <query>').
+        Strip known instructional prefixes so the search backend receives only
+        the intended search terms rather than query wrapper keywords.
+        """
+        cleaned = _CLAUDE_CODE_SEARCH_PREFIX_RE.sub("", raw_message).strip()
+        if (cleaned.startswith('"') and cleaned.endswith('"')) or (cleaned.startswith("'") and cleaned.endswith("'")):
+            cleaned = cleaned[1:-1].strip()
+        return cleaned if cleaned else raw_message.strip()
+
     async def try_short_circuit_search(
         self,
         model: str,
@@ -358,7 +378,11 @@ class WebSearchInterceptionLogger(CustomLogger):
             get_last_user_message,
         )
 
-        query: Final = get_last_user_message(cast(list[AllMessageValues], messages))
+        raw_query: Final = get_last_user_message(cast(list[AllMessageValues], messages))
+        if not raw_query:
+            return None
+
+        query: Final = self._extract_short_circuit_query(raw_query)
         if not query:
             return None
 

tests/unit/integrations/websearch_interception/test_websearch_short_circuit.py

@@ -392,3 +392,61 @@ class TestShortCircuitEntryPoint:
         assert result is not None
         text_block = next(b for b in result["content"] if b["type"] == "text")
         assert text_block["text"] == "results"
+
+    @pytest.mark.asyncio
+    @pytest.mark.parametrize(
+        "raw_prompt,expected_query",
+        [
+            (
+                "Perform a web search for the query: LiteLLM latest version release",
+                "LiteLLM latest version release",
+            ),
+            (
+                'Perform a web search for the query: "who is the maintainer of litellm"',
+                "who is the maintainer of litellm",
+            ),
+            (
+                "   perform a web search for the query:   fastapi SSE streaming   ",
+                "fastapi SSE streaming",
+            ),
+            (
+                "Search for the query: python 3.13 changelog",
+                "python 3.13 changelog",
+            ),
+            (
+                "Search for Claude Code releases",
+                "Search for Claude Code releases",
+            ),
+        ],
+    )
+    async def test_short_circuits_strips_claude_code_instructional_prefix(
+        self, raw_prompt, expected_query
+    ):
+        """Claude Code wraps standalone searches in 'Perform a web search for the query: ...'.
+        The short-circuit path must extract only the actual query terms so search backends
+        receive the intended query rather than instructional prefix words.
+        """
+        logger = WebSearchInterceptionLogger(enabled_providers=["github_copilot"])
+
+        with patch.object(
+            logger, "_execute_search", new_callable=AsyncMock
+        ) as mock_search:
+            mock_search.return_value = ("Results", None)
+
+            result = await logger.try_short_circuit_search(
+                model="github_copilot/claude-sonnet-4",
+                messages=[{"role": "user", "content": raw_prompt}],
+                tools=[
+                    {"type": "web_search_20250305", "name": "web_search", "max_uses": 8}
+                ],
+                custom_llm_provider="github_copilot",
+            )
+
+        assert result is not None
+        mock_search.assert_called_once_with(expected_query)
+        tool_use_block = next(
+            (b for b in result["content"] if b["type"] == "server_tool_use"), None
+        )
+        if tool_use_block is not None:
+            assert tool_use_block["input"]["query"] == expected_query
+