Merge f47a957aee into aeede53112

litellm/litellm_core_utils/litellm_logging.py

@@ -7538,7 +7538,7 @@ class StandardLoggingPayloadSetup:
             return None
         user_agent_tags: list[str] | None = None
         headers: Final = proxy_server_request.get("headers", {})
-        if headers is not None and isinstance(headers, dict):
+        if headers is not None and isinstance(headers, Mapping):
             request_headers: Final = cast(  # cast-ok: request headers are untyped framework data
                 dict[str, str | None], headers
             )
@@ -7565,7 +7565,7 @@ class StandardLoggingPayloadSetup:
             return None
 
         headers: Final = proxy_server_request.get("headers", {})
-        if not isinstance(headers, dict):
+        if not isinstance(headers, Mapping):
             return None
         request_headers: Final = cast(  # cast-ok: request headers are untyped framework data
             dict[str, str], headers

tests/unit/litellm_core_utils/test_litellm_logging.py

@@ -3989,6 +3989,46 @@ def test_get_request_tags_includes_extra_header_tag_with_user_agent_tags(
     ) == ["User-Agent: litellm", "User-Agent: litellm/1.0", "X-Org-Id: org_1"]
 
 
+def test_header_derived_spend_tags_accept_starlette_headers_mapping(monkeypatch):
+    """Pass-through stores Starlette Headers (a Mapping, not dict); tags must still extract.
+
+    Regression for https://github.com/BerriAI/litellm/issues/44032
+    """
+    import litellm
+    from starlette.datastructures import Headers
+
+    from litellm.litellm_core_utils.litellm_logging import StandardLoggingPayloadSetup
+
+    monkeypatch.setattr(litellm, "disable_add_user_agent_to_request_tags", False)
+    monkeypatch.setattr(
+        litellm, "extra_spend_tag_headers", ["x-custom-header"], raising=False
+    )
+    proxy_server_request = {
+        "headers": Headers(
+            {
+                "user-agent": "curl/8.0.0",
+                "x-custom-header": "tenant-a",
+            }
+        )
+    }
+
+    ua_tags = StandardLoggingPayloadSetup._get_user_agent_tags(proxy_server_request)
+    assert ua_tags is not None
+    assert "User-Agent: curl" in ua_tags
+    assert "User-Agent: curl/8.0.0" in ua_tags
+
+    extra_tags = StandardLoggingPayloadSetup._get_extra_header_tags(proxy_server_request)
+    assert extra_tags is not None
+    assert "x-custom-header: tenant-a" in extra_tags
+
+    request_tags = StandardLoggingPayloadSetup.get_request_tags(
+        litellm_params={},
+        proxy_server_request=proxy_server_request,
+    )
+    assert "User-Agent: curl" in request_tags
+    assert "x-custom-header: tenant-a" in request_tags
+
+
 def test_response_cost_calculator_with_response_cost_in_hidden_params(logging_obj):
     from litellm import Router