diff --git a/litellm/litellm_core_utils/core_helpers.py b/litellm/litellm_core_utils/core_helpers.py
index b095b4b12c6..64f94ed3799 100644
--- a/litellm/litellm_core_utils/core_helpers.py
+++ b/litellm/litellm_core_utils/core_helpers.py
@@ -339,6 +339,13 @@ def get_or_create_metadata_bucket(
     return metadata_key, metadata_bucket
 
 
+def proxy_stamped_used_client_oauth_token(metadata: object, litellm_params: Mapping[str, object] | None) -> object:
+    litellm_metadata: Final = litellm_params.get("litellm_metadata") if litellm_params is not None else None
+    if isinstance(litellm_metadata, Mapping) and "used_client_oauth_token" in litellm_metadata:
+        return litellm_metadata["used_client_oauth_token"]
+    return metadata.get("used_client_oauth_token") if isinstance(metadata, Mapping) else None
+
+
 def get_litellm_metadata_from_kwargs(kwargs: dict):
     """
     Helper to get litellm metadata from all litellm request kwargs
diff --git a/litellm/litellm_core_utils/litellm_logging.py b/litellm/litellm_core_utils/litellm_logging.py
index 7784addb215..3958cda3efe 100644
--- a/litellm/litellm_core_utils/litellm_logging.py
+++ b/litellm/litellm_core_utils/litellm_logging.py
@@ -71,6 +71,7 @@ from litellm.litellm_core_utils.classifier_logging import (
 from litellm.litellm_core_utils.core_helpers import (
     get_provider_response_headers_from_hidden_params,
     is_expected_client_error,
+    proxy_stamped_used_client_oauth_token,
     reconstruct_model_name,
     set_response_cost_in_hidden_params,
 )
@@ -288,13 +289,6 @@ _STANDARD_LOGGING_METADATA_KEYS: Final[frozenset[str]] = (
 )
 
 
-def _proxy_stamped_used_client_oauth_token(metadata: object, litellm_params: Mapping[str, object] | None) -> object:
-    litellm_metadata: Final = litellm_params.get("litellm_metadata") if litellm_params is not None else None
-    if isinstance(litellm_metadata, Mapping) and "used_client_oauth_token" in litellm_metadata:
-        return litellm_metadata["used_client_oauth_token"]
-    return metadata.get("used_client_oauth_token") if isinstance(metadata, Mapping) else None
-
-
 def _get_provider_request_id(original_exception: Exception) -> str | None:
     try:
         error_response: Final = getattr(original_exception, "response", None)
@@ -5793,7 +5787,7 @@ class StandardLoggingPayloadSetup:
             team_alias=None,
             team_id=None,
             used_client_oauth_token=resolve_used_client_oauth_token(
-                _proxy_stamped_used_client_oauth_token(metadata, litellm_params),
+                proxy_stamped_used_client_oauth_token(metadata, litellm_params),
                 custom_llm_provider,
             ),
         )
diff --git a/litellm/proxy/hooks/proxy_track_cost_callback.py b/litellm/proxy/hooks/proxy_track_cost_callback.py
index bd53adeec41..76c9ea48948 100644
--- a/litellm/proxy/hooks/proxy_track_cost_callback.py
+++ b/litellm/proxy/hooks/proxy_track_cost_callback.py
@@ -30,7 +30,7 @@ from litellm.proxy.db.db_spend_update_writer import (
     debitable_model_access_groups,
     get_llm_router,
 )
-from litellm.proxy.litellm_pre_call_utils import LiteLLMProxyRequestSetup
+from litellm.proxy.litellm_pre_call_utils import LiteLLMProxyRequestSetup, metadata_variable_name_for_route
 from litellm.proxy.spend_tracking.spend_event import (
     ObjectMapping,
     SpendEventBuildError,
@@ -86,8 +86,15 @@ _CAPTURED_IDENTITY_CALL_TYPES: Final[frozenset[str]] = frozenset(
 )
 
 
-def _proxy_stamped_used_client_oauth_token(request_data: Mapping[str, object]) -> bool | None:
-    proxy_metadata: Final = request_data.get(get_metadata_variable_name_from_kwargs(request_data))
+def _proxy_stamped_used_client_oauth_token(
+    request_data: Mapping[str, object], request_route: str | None
+) -> bool | None:
+    proxy_bucket: Final = (
+        get_metadata_variable_name_from_kwargs(request_data)
+        if request_route is None
+        else metadata_variable_name_for_route(request_route)
+    )
+    proxy_metadata: Final = request_data.get(proxy_bucket)
     stamped: Final = proxy_metadata.get("used_client_oauth_token") if isinstance(proxy_metadata, dict) else None
     return stamped if isinstance(stamped, bool) else None
 
@@ -198,7 +205,7 @@ class _ProxyDBLogger(CustomLogger):
             metadata=_metadata, original_exception=original_exception
         )
 
-        _metadata["used_client_oauth_token"] = _proxy_stamped_used_client_oauth_token(request_data)
+        _metadata["used_client_oauth_token"] = _proxy_stamped_used_client_oauth_token(request_data, request_route)
 
         existing_metadata: Final[dict] = request_data.get("metadata", None) or {}
         existing_metadata.update(_metadata)
diff --git a/litellm/proxy/litellm_pre_call_utils.py b/litellm/proxy/litellm_pre_call_utils.py
index 4a501eb3d09..bbd3ed66ff4 100644
--- a/litellm/proxy/litellm_pre_call_utils.py
+++ b/litellm/proxy/litellm_pre_call_utils.py
@@ -7,7 +7,7 @@ from collections import OrderedDict
 from collections.abc import Mapping, MutableMapping, Sequence
 from datetime import datetime
 from types import MappingProxyType
-from typing import TYPE_CHECKING, Any, Final, cast
+from typing import TYPE_CHECKING, Any, Final, Literal, cast
 
 from fastapi import HTTPException, Request
 from pydantic import TypeAdapter
@@ -649,11 +649,14 @@ def _get_metadata_variable_name(request: Request) -> str:
     # Inline imports — auth_utils/route_checks participate in a proxy import cycle.
     from litellm.proxy.auth.auth_utils import get_request_route  # noqa: PLC0415
 
-    path: Final = get_request_route(request)
-    if "thread" in path or "assistant" in path:
+    return metadata_variable_name_for_route(get_request_route(request))
+
+
+def metadata_variable_name_for_route(route: str) -> Literal["metadata", "litellm_metadata"]:
+    if "thread" in route or "assistant" in route:
         return "litellm_metadata"
 
-    if any(route in path for route in LITELLM_METADATA_ROUTES):
+    if any(metadata_route in route for metadata_route in LITELLM_METADATA_ROUTES):
         return "litellm_metadata"
 
     return "metadata"
diff --git a/litellm/proxy/spend_tracking/spend_tracking_utils.py b/litellm/proxy/spend_tracking/spend_tracking_utils.py
index 79f8e72d2aa..d736739c57d 100644
--- a/litellm/proxy/spend_tracking/spend_tracking_utils.py
+++ b/litellm/proxy/spend_tracking/spend_tracking_utils.py
@@ -33,6 +33,7 @@ from litellm.constants import (
 from litellm.litellm_core_utils.classifier_logging import classifier_audit_fields, without_classifier_audit
 from litellm.litellm_core_utils.core_helpers import (
     get_litellm_metadata_from_kwargs,
+    proxy_stamped_used_client_oauth_token,
     reconstruct_model_name,
 )
 from litellm.litellm_core_utils.get_llm_provider_logic import declared_authenticating_provider
@@ -720,7 +721,7 @@ def get_logging_payload(
             router_correlation_id=litellm_call_id,
         ),
         used_client_oauth_token=resolve_used_client_oauth_token(
-            metadata.get("used_client_oauth_token") if metadata is not None else None, custom_llm_provider
+            proxy_stamped_used_client_oauth_token(litellm_params.get("metadata"), litellm_params), custom_llm_provider
         ),
         azure_spillover=azure_spillover(
             response_headers=kwargs.get("response_headers")
diff --git a/tests/test_litellm/proxy/hooks/test_proxy_track_cost_callback.py b/tests/test_litellm/proxy/hooks/test_proxy_track_cost_callback.py
index 06fdcba7b70..44c5f7a9d1b 100644
--- a/tests/test_litellm/proxy/hooks/test_proxy_track_cost_callback.py
+++ b/tests/test_litellm/proxy/hooks/test_proxy_track_cost_callback.py
@@ -245,6 +245,53 @@ async def test_async_post_call_failure_hook_never_lets_caller_metadata_set_used_
     assert json.loads(payload["metadata"])["used_client_oauth_token"] is expected
 
 
+@pytest.mark.asyncio
+@pytest.mark.parametrize(
+    "request_route, metadata_buckets, expected",
+    [
+        (
+            "/v1/chat/completions",
+            {"metadata": {"used_client_oauth_token": True}, "litellm_metadata": {"user_api_key_hash": "guardrail"}},
+            True,
+        ),
+        (
+            "/v1/messages",
+            {"metadata": {"used_client_oauth_token": True}, "litellm_metadata": {"user_api_key_hash": "proxy"}},
+            None,
+        ),
+    ],
+)
+async def test_async_post_call_failure_hook_reads_used_client_oauth_token_from_the_routes_stamped_bucket(
+    request_route: str, metadata_buckets: dict, expected: bool | None
+):
+    logger = _ProxyDBLogger()
+    request_data = {
+        "model": "claude-sonnet-5",
+        "custom_llm_provider": "anthropic",
+        "messages": [{"role": "user", "content": "Hello"}],
+        "proxy_server_request": {"request_id": "test_request_id"},
+        **metadata_buckets,
+    }
+
+    with patch(
+        "litellm.proxy.db.db_spend_update_writer.DBSpendUpdateWriter.update_database",
+        new_callable=AsyncMock,
+    ) as mock_update_database:
+        await logger.async_post_call_failure_hook(
+            request_data=request_data,
+            original_exception=Exception("rate limited"),
+            user_api_key_dict=UserAPIKeyAuth(api_key="test_api_key", request_route=request_route),
+        )
+
+    payload = get_logging_payload(
+        kwargs=mock_update_database.call_args[1]["kwargs"],
+        response_obj={},
+        start_time=datetime.now(),
+        end_time=datetime.now(),
+    )
+    assert json.loads(payload["metadata"])["used_client_oauth_token"] is expected
+
+
 @pytest.mark.asyncio
 async def test_async_post_call_failure_hook_bills_guardrail_cost_on_blocked_request():
     """LIT-5651: a request blocked by a guardrail never reaches the LLM, but the
diff --git a/tests/test_litellm/proxy/spend_tracking/test_spend_tracking_utils.py b/tests/test_litellm/proxy/spend_tracking/test_spend_tracking_utils.py
index 05c6a556da1..fb351d75cc4 100644
--- a/tests/test_litellm/proxy/spend_tracking/test_spend_tracking_utils.py
+++ b/tests/test_litellm/proxy/spend_tracking/test_spend_tracking_utils.py
@@ -3305,6 +3305,31 @@ def test_get_logging_payload_records_used_client_oauth_token_for_the_selected_pr
     assert _get_spend_logs_metadata(None)["used_client_oauth_token"] is None
 
 
+@pytest.mark.parametrize(
+    "litellm_params, expected",
+    [
+        (
+            {"metadata": {"used_client_oauth_token": True}, "litellm_metadata": {"user_api_key_hash": "guardrail"}},
+            True,
+        ),
+        (
+            {"metadata": {"used_client_oauth_token": True}, "litellm_metadata": {"used_client_oauth_token": False}},
+            False,
+        ),
+    ],
+)
+def test_get_logging_payload_reads_used_client_oauth_token_from_the_bucket_the_proxy_stamped(
+    litellm_params: dict, expected: bool
+):
+    payload = get_logging_payload(
+        kwargs={"model": "claude-sonnet-5", "custom_llm_provider": "anthropic", "litellm_params": litellm_params},
+        response_obj={},
+        start_time=datetime.datetime.now(timezone.utc),
+        end_time=datetime.datetime.now(timezone.utc),
+    )
+    assert json.loads(payload["metadata"])["used_client_oauth_token"] is expected
+
+
 def test_redact_logged_api_key_bearer_only_returns_none():
     # "bearer " with nothing after stripping is equivalent to no key
     assert _redact_logged_api_key("bearer ") is None