refactor(identity): rely on Starlette Headers case-insensitivity in extract_client_info

litellm/identity/extractors/client.py

@@ -6,7 +6,7 @@ The trust logic is delegated to ``IPAddressUtils.is_request_from_trusted_proxy``
 so we stay in sync with the rest of the proxy.
 """
 
-from typing import Any, Dict, List, Optional
+from typing import Any, Dict, List, Mapping, Optional
 
 from litellm.identity.context import ClientInfo
 
@@ -29,32 +29,16 @@ def extract_client_info(
     request: Any,
     general_settings: Optional[Dict[str, Any]] = None,
 ) -> ClientInfo:
-    headers = getattr(request, "headers", {}) or {}
+    headers: Mapping[str, str] = getattr(request, "headers", {}) or {}
     forwarded_chain: List[str] = []
-    ip: Optional[str] = None
 
-    # Headers in FastAPI are case-insensitive; normalize defensively for dicts.
-    def _get_header(name: str) -> Optional[str]:
-        try:
-            value = headers.get(name)
-        except AttributeError:
-            return None
-        if value is not None:
-            return value
-        try:
-            for key, val in headers.items():
-                if isinstance(key, str) and key.lower() == name:
-                    return val
-        except Exception:
-            return None
-        return None
-
-    xff = _get_header("x-forwarded-for")
+    xff = headers.get("x-forwarded-for")
     if xff:
         forwarded_chain = _split_forwarded_chain(xff)
 
     from litellm.proxy.auth.ip_address_utils import IPAddressUtils
 
+    ip: Optional[str]
     if forwarded_chain and IPAddressUtils.is_request_from_trusted_proxy(
         request=request, general_settings=general_settings
     ):
@@ -62,7 +46,7 @@ def extract_client_info(
     else:
         ip = _direct_client_host(request)
 
-    user_agent = _get_header("user-agent")
+    user_agent = headers.get("user-agent")
 
     return ClientInfo(
         ip=ip,

tests/test_litellm/identity/extractors/test_client.py

@@ -45,3 +45,15 @@ def test_user_agent_passthrough():
     req = _fake_request({"user-agent": "curl/8"}, client_host="127.0.0.1")
     info = extract_client_info(req, general_settings={})
     assert info.user_agent == "curl/8"
+
+
+def test_extract_client_info_uses_starlette_headers_case_insensitively():
+    from starlette.datastructures import Headers
+
+    req = _fake_request(
+        Headers({"X-Forwarded-For": "1.2.3.4", "User-Agent": "curl/8"}),
+        client_host="127.0.0.1",
+    )
+    info = extract_client_info(req, general_settings={})
+    assert info.forwarded_chain == ["1.2.3.4"]
+    assert info.user_agent == "curl/8"