fix(proxy)!: log and bill Responses-style bodies sent to /cursor/chat/completions (#30277)

* fix(proxy): restore spend logging for /cursor/chat/completions (#30126)

The /cursor/chat/completions route processes requests through the Responses API pipeline, but _get_metadata_variable_name did not treat it as a litellm_metadata route. Proxy auth metadata therefore landed in the user-facing metadata param, so the spend tracking callback saw user_api_key=None and silently skipped the SpendLogs write. Add the route to LITELLM_METADATA_ROUTES and cover it with regression tests.

* test(proxy): pin provider metadata and key billing on /cursor/chat/completions

A Responses-format body on the Cursor route now sends OpenAI only the metadata the client sent and writes a spend row that bills the key. The chat-body branch, which this fix also moves onto litellm_metadata, still bills the key with its team and request tags. The scripted chat reply gets a unique id per test, since a shared id let only the first spend row per database land

* fix(proxy): pick the Cursor route's metadata field from the body shape

A Responses-style body on /cursor/chat/completions keeps proxy metadata in
litellm_metadata, the same as /v1/responses, while a Chat Completions body
keeps metadata, the same as /v1/chat/completions. Adding the whole route to
the internal-metadata list let a client's chat-body tags replace the key's
tags in spend logs and skip tag budgets.

* fix(proxy): keep get_metadata_variable_name callable with only the request

* fix(proxy): check client tags against tag budgets and read agent limits from litellm_metadata on Responses bodies

A Responses-style body on /cursor/chat/completions now keeps its proxy fields in litellm_metadata, so the pre-call tag budget check and the v3 agent rate limiter stopped seeing the client's metadata.tags and the x-litellm-agent-id value. The pre-auth tag check now merges the caller's metadata.tags into the selected metadata field, sharing one helper with request setup, and the limiter reads agent_id from either field

* fix(proxy): check client tags sent in a JSON-string metadata against tag budgets on Responses bodies

* fix(proxy): answer 422, not 500, when a budget rejects a Responses body whose metadata is a JSON string

* fix(proxy): keep key guardrails, metadata type errors and failure-row client details on Responses-style bodies

---------

Co-authored-by: mateo-berri <277851410+mateo-berri@users.noreply.github.com>

litellm/integrations/custom_guardrail.py

@@ -9,6 +9,7 @@ from types import MappingProxyType
 from typing import TYPE_CHECKING, Any, ClassVar, Final, Literal, Optional, cast, get_args
 
 import httpx
+from pydantic import TypeAdapter
 
 from litellm._internal_context import with_service_target
 from litellm._logging import verbose_logger
@@ -218,6 +219,15 @@ def _request_is_streaming(data: object, event_type: GuardrailEventHooks | None =
     )
 
 
+_REQUEST_FIELDS: Final = TypeAdapter(Mapping[str, object])
+
+
+def _guardrails_listed_in(metadata: object) -> list[str | dict[str, DynamicGuardrailParams]]:
+    if not isinstance(metadata, dict):
+        return []
+    return metadata.get("guardrails") or []
+
+
 class CustomGuardrail(CustomLogger):
     # If True, during_call runs async_moderation_hook instead of the unified apply_guardrail path.
     use_native_during_call_hook: ClassVar[bool] = False
@@ -791,28 +801,22 @@ class CustomGuardrail(CustomLogger):
                 return True
             raise
 
-    def get_guardrail_from_metadata(self, data: dict) -> list[str] | list[dict[str, DynamicGuardrailParams]]:
+    def get_guardrail_from_metadata(self, data: dict) -> list[str | dict[str, DynamicGuardrailParams]]:
         """
-        Returns the guardrail(s) to be run from the metadata or root
+        Returns the guardrail(s) to be run from the root, else from both metadata fields together
         """
 
         if "guardrails" in data:
             return data["guardrails"]
-        # Check both metadata locations. For regular endpoints move_guardrails_to_metadata
-        # writes to "metadata"; for thread/assistant endpoints it writes to
-        # "litellm_metadata". We check the one that actually contains the "guardrails"
-        # key so that a non-empty litellm_metadata without guardrails does not shadow
-        # the merged list stored in metadata (which would cause team guardrails to be
-        # silently skipped while default_on=True policy guardrails still fire).
-        for meta_key in ("metadata", "litellm_metadata"):
-            meta = data.get(meta_key) or {}
-            if isinstance(meta, dict) and "guardrails" in meta:
-                return meta.get("guardrails") or []
-        return []
+        request_fields: Final = _REQUEST_FIELDS.validate_python(data)
+        return [
+            *_guardrails_listed_in(request_fields.get("metadata")),
+            *_guardrails_listed_in(request_fields.get("litellm_metadata")),
+        ]
 
     def _guardrail_is_in_requested_guardrails(
         self,
-        requested_guardrails: list[str] | list[dict[str, DynamicGuardrailParams]],
+        requested_guardrails: Sequence[str | dict[str, DynamicGuardrailParams]],
     ) -> bool:
         for _guardrail in requested_guardrails:
             if isinstance(_guardrail, dict):

litellm/proxy/auth/auth_checks.py

@@ -446,7 +446,7 @@ def _request_has_trace_id(request_body: Mapping[str, object], request: Request,
     from litellm.proxy.litellm_pre_call_utils import (
         _trace_id_from_traceparent,  # pyright: ignore[reportPrivateUsage]  # reuse W3C traceparent parser
         get_chain_id_from_headers,
-        metadata_variable_name_for_route,
+        metadata_variable_name_for_request,
     )
 
     if get_chain_id_from_headers(dict(request.headers)):
@@ -460,7 +460,7 @@ def _request_has_trace_id(request_body: Mapping[str, object], request: Request,
         traceparent: Final[str | None] = request.headers.get("traceparent")
         if isinstance(traceparent, str) and _trace_id_from_traceparent(traceparent):
             return True
-    metadata_variable_name: Final = metadata_variable_name_for_route(get_request_route(request))
+    metadata_variable_name: Final = metadata_variable_name_for_request(get_request_route(request), request_body)
     selected_metadata: Final[object] = request_body.get(metadata_variable_name)
     if isinstance(selected_metadata, dict):
         selected_metadata_dict: Final = _TRACE_ID_METADATA_ADAPTER.validate_python(selected_metadata)
@@ -1367,11 +1367,15 @@ async def common_checks(
     if not skip_all_budget_checks:
         # Key metadata.tags are injected into request_body here so the tag budget
         # check can read them; this mutation must run before the gathered checks.
-        from litellm.proxy.litellm_pre_call_utils import LiteLLMProxyRequestSetup
+        from litellm.proxy.litellm_pre_call_utils import LiteLLMProxyRequestSetup, metadata_variable_name_for_request
 
         if valid_token is not None:
             for tag_target in LiteLLMProxyRequestSetup.pre_auth_tag_merge_targets(request, request_body):
                 LiteLLMProxyRequestSetup.pre_seed_litellm_metadata_for_route(request_data=tag_target, route=route)
+                LiteLLMProxyRequestSetup.merge_caller_body_tags(
+                    request_data=tag_target,
+                    metadata_variable_name=metadata_variable_name_for_request(route, tag_target),
+                )
                 LiteLLMProxyRequestSetup.apply_key_tags_pre_auth(request_data=tag_target, user_api_key_dict=valid_token)
         LiteLLMProxyRequestSetup.apply_authenticated_baggage_tags(request, request_body)
 

litellm/proxy/common_request_processing.py

@@ -2401,9 +2401,10 @@ class ProxyBaseLLMRequestProcessing:
             version=version,
             proxy_config=proxy_config,
         )
+        request_fields: Final = _REQUEST_FIELDS.validate_python(self.data)
+        metadata_variable_name: Final = get_metadata_variable_name(request, request_fields)
         if logging_auth is not None:
-            metadata_variable_name: Final = get_metadata_variable_name(request)
-            request_metadata: Final = self.data.get(metadata_variable_name)
+            request_metadata: Final = request_fields.get(metadata_variable_name)
             if isinstance(request_metadata, dict):
                 self.data[metadata_variable_name] = {
                     **TypeAdapter(dict[str, object]).validate_python(request_metadata),
@@ -2431,12 +2432,11 @@ class ProxyBaseLLMRequestProcessing:
 
         # Store queue time in metadata after add_litellm_data_to_request to ensure it's preserved
         if queue_time_seconds is not None:
-            _metadata_variable_name: Final = get_metadata_variable_name(request)
-            if _metadata_variable_name not in self.data:
-                self.data[_metadata_variable_name] = {}
-            if not isinstance(self.data[_metadata_variable_name], dict):
-                self.data[_metadata_variable_name] = {}
-            self.data[_metadata_variable_name]["queue_time_seconds"] = queue_time_seconds
+            if metadata_variable_name not in self.data:
+                self.data[metadata_variable_name] = {}
+            if not isinstance(self.data[metadata_variable_name], dict):
+                self.data[metadata_variable_name] = {}
+            self.data[metadata_variable_name]["queue_time_seconds"] = queue_time_seconds
 
         if isinstance(model, str):
             reject_url_valued_destination("model", model)

litellm/proxy/hooks/parallel_request_limiter_v3.py

@@ -3312,7 +3312,8 @@ class _PROXY_MaxParallelRequestsHandler_v3(CustomLogger):
         if key_agent_id:
             return key_agent_id
         metadata: Final = data.get("metadata") or {}
-        return metadata.get("agent_id")
+        litellm_metadata: Final = data.get("litellm_metadata") or {}
+        return metadata.get("agent_id") or litellm_metadata.get("agent_id")
 
     def _get_session_id_from_data(self, data: dict) -> str | None:
         """Extract session_id from request metadata or litellm_session_id."""

litellm/proxy/hooks/proxy_track_cost_callback.py

@@ -37,7 +37,7 @@ from litellm.proxy.db.db_spend_update_writer import (
     get_llm_router,
 )
 from litellm.proxy.hooks.search_free_tier import apply_search_free_tier
-from litellm.proxy.litellm_pre_call_utils import LiteLLMProxyRequestSetup, metadata_variable_name_for_route
+from litellm.proxy.litellm_pre_call_utils import LiteLLMProxyRequestSetup, metadata_variable_name_for_request
 from litellm.proxy.route_llm_request import ProxyModelNotFoundError
 from litellm.proxy.spend_tracking.spend_counter_batch import post_call_counter_keys, spend_counter_batch_scope
 from litellm.proxy.spend_tracking.spend_event import (
@@ -137,19 +137,34 @@ _CAPTURED_IDENTITY_CALL_TYPES: Final[frozenset[str]] = frozenset(
 _OBJECT_MAPPING: Final = TypeAdapter(ObjectMapping)
 
 
-def _proxy_stamped_used_client_oauth_token(
-    request_data: Mapping[str, object], request_route: str | None
-) -> bool | None:
+def _proxy_stamped_metadata(request_data: Mapping[str, object], request_route: str | None) -> Mapping[str, object]:
     proxy_bucket: Final = (
         get_metadata_variable_name_from_kwargs(request_data)
         if request_route is None
-        else metadata_variable_name_for_route(request_route)
+        else metadata_variable_name_for_request(request_route, request_data)
     )
-    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 _str_keyed_fields(request_data.get(proxy_bucket))
+
+
+def _proxy_stamped_used_client_oauth_token(
+    request_data: Mapping[str, object], request_route: str | None
+) -> bool | None:
+    stamped: Final = _proxy_stamped_metadata(request_data, request_route).get("used_client_oauth_token")
     return stamped if isinstance(stamped, bool) else None
 
 
+_PROXY_STAMPED_REQUEST_FIELDS: Final = ("requester_ip_address", "user_agent")
+
+
+def _proxy_stamped_request_fields(
+    request_data: Mapping[str, object], request_route: str | None
+) -> Mapping[str, object]:
+    if request_route is None:
+        return {}
+    proxy_metadata: Final = _proxy_stamped_metadata(request_data, request_route)
+    return {field: proxy_metadata[field] for field in _PROXY_STAMPED_REQUEST_FIELDS if field in proxy_metadata}
+
+
 def _str_keyed_fields(value: object) -> Mapping[str, object]:
     return value if is_str_keyed_mapping(value) else {}
 
@@ -455,7 +470,13 @@ class _ProxyDBLogger(CustomLogger):
         _metadata["used_client_oauth_token"] = _proxy_stamped_used_client_oauth_token(request_fields, request_route)
 
         existing_metadata: Final[dict] = request_data.get("metadata", None) or {}
-        existing_metadata.update({**_routed_metadata_fallback(request_fields), **_metadata})
+        existing_metadata.update(
+            {
+                **_routed_metadata_fallback(request_fields),
+                **_proxy_stamped_request_fields(request_fields, request_route),
+                **_metadata,
+            }
+        )
 
         litellm_metadata_bucket: Final = request_data.get("litellm_metadata")
         litellm_metadata: Final[ObjectMapping] = (

litellm/proxy/litellm_pre_call_utils.py

@@ -379,6 +379,8 @@ LITELLM_METADATA_ROUTES: Final = (
     "interactions",
 )
 
+CURSOR_CHAT_COMPLETIONS_ROUTE: Final = "/cursor/chat/completions"
+
 LITELLM_TRACE_CONTROL_METADATA_FIELDS: Final = frozenset(
     {
         "mask_input",
@@ -636,7 +638,7 @@ def _has_tag_budget(tag: "LiteLLM_TagTable | None") -> bool:
     return tag.litellm_budget_table.max_budget is not None
 
 
-def _normalized_metadata_slot(
+def normalized_metadata_slot(
     request_data: MutableMapping[str, object], metadata_variable_name: str
 ) -> dict[str, object]:
     """Return the request's metadata slot as a dict, normalising it in place first.
@@ -653,6 +655,12 @@ def _normalized_metadata_slot(
     return normalized
 
 
+def _holds_metadata_object(value: object) -> bool:
+    if value is None or isinstance(value, dict):
+        return True
+    return isinstance(value, str) and isinstance(_DECODED_JSON.validate_python(safe_json_loads(value)), dict)
+
+
 def _metadata_object_or_error(field: str, value: object) -> Mapping[str, object] | ProxyException:
     if value is None:
         return {}
@@ -863,7 +871,7 @@ def _strip_router_reserved_metadata(
             )
 
 
-def get_metadata_variable_name(request: Request) -> str:
+def get_metadata_variable_name(request: Request, data: Mapping[str, object] | None = None) -> str:
     """
     Helper to return what the "metadata" field should be called in the request data
 
@@ -874,7 +882,10 @@ 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
 
-    return metadata_variable_name_for_route(get_request_route(request))
+    route: Final = get_request_route(request)
+    if data is None:
+        return metadata_variable_name_for_route(route)
+    return metadata_variable_name_for_request(route, data)
 
 
 _get_metadata_variable_name: Final = get_metadata_variable_name
@@ -890,6 +901,25 @@ def metadata_variable_name_for_route(route: str) -> Literal["metadata", "litellm
     return "metadata"
 
 
+def is_chat_completions_body(data: Mapping[str, object]) -> bool:
+    messages: Final = data.get("messages")
+    if isinstance(messages, list) and messages:
+        return True
+    return "messages" in data and "input" not in data
+
+
+def is_cursor_responses_request(route: str, body: Mapping[str, object]) -> bool:
+    return CURSOR_CHAT_COMPLETIONS_ROUTE in route and not is_chat_completions_body(body)
+
+
+def metadata_variable_name_for_request(
+    route: str, body: Mapping[str, object]
+) -> Literal["metadata", "litellm_metadata"]:
+    if is_cursor_responses_request(route, body):
+        return "litellm_metadata"
+    return metadata_variable_name_for_route(route)
+
+
 def _promoted_trace_control_fields(
     requester_metadata: Mapping[str, object],
     litellm_metadata: Mapping[str, object],
@@ -2309,7 +2339,9 @@ class LiteLLMProxyRequestSetup:
         ``_tag_max_budget_check`` resolve to ``litellm_metadata``, leaving
         header tags invisible to per-tag budget enforcement.
         """
-        if any(metadata_route in route for metadata_route in LITELLM_METADATA_ROUTES):
+        if any(metadata_route in route for metadata_route in LITELLM_METADATA_ROUTES) or is_cursor_responses_request(
+            route, request_data
+        ):
             request_data.setdefault("litellm_metadata", {})
 
     @staticmethod
@@ -2380,7 +2412,7 @@ class LiteLLMProxyRequestSetup:
             return
         tags: Final = _STRING_TAGS_ADAPTER.validate_python(raw_tags)
         slot: Final = metadata_key if metadata_key is not None else get_metadata_variable_name_from_kwargs(request_data)
-        metadata: Final = _normalized_metadata_slot(request_data, slot)
+        metadata: Final = normalized_metadata_slot(request_data, slot)
         existing: Final = metadata.get("tags")
         if existing and not isinstance(existing, list):
             return
@@ -2393,6 +2425,34 @@ class LiteLLMProxyRequestSetup:
             tags=tuple(tag for tag in tags if tag not in sent_tags)
         )
 
+    @staticmethod
+    def merge_caller_body_tags(
+        request_data: MutableMapping[str, object],  # mutable-ok: the request body the tag merges write into
+        metadata_variable_name: str | None = None,
+    ) -> None:
+        slot: Final = (
+            metadata_variable_name
+            if metadata_variable_name is not None
+            else get_metadata_variable_name_from_kwargs(request_data)
+        )
+        if slot == "metadata" or not _holds_metadata_object(request_data.get(slot)):
+            return
+        raw_caller_metadata: Final = request_data.get("metadata")
+        caller_metadata: Final = (
+            _DECODED_JSON.validate_python(safe_json_loads(raw_caller_metadata))
+            if isinstance(raw_caller_metadata, str)
+            else raw_caller_metadata
+        )
+        caller_tags: Final = caller_metadata.get("tags") if isinstance(caller_metadata, dict) else None
+        if not isinstance(caller_tags, list) or not caller_tags:
+            return
+        metadata: Final = normalized_metadata_slot(request_data, slot)
+        existing_tags: Final = metadata.get("tags")
+        metadata["tags"] = LiteLLMProxyRequestSetup.merge_tags(
+            request_tags=existing_tags if isinstance(existing_tags, list) else None,
+            tags_to_add=caller_tags,
+        )
+
     @staticmethod
     def apply_key_tags_pre_auth(
         request_data: dict,
@@ -2408,7 +2468,7 @@ class LiteLLMProxyRequestSetup:
             return
 
         _metadata_variable_name: Final = get_metadata_variable_name_from_kwargs(request_data)
-        metadata: Final = _normalized_metadata_slot(request_data, _metadata_variable_name)
+        metadata: Final = normalized_metadata_slot(request_data, _metadata_variable_name)
 
         existing_tags: Final = metadata.get("tags")
         metadata["tags"] = LiteLLMProxyRequestSetup.merge_tags(
@@ -2460,7 +2520,7 @@ class LiteLLMProxyRequestSetup:
         # from (litellm_metadata vs metadata) so the merged tags are visible
         # to _tag_max_budget_check.
         _metadata_variable_name: Final = get_metadata_variable_name_from_kwargs(request_data)
-        metadata: Final = _normalized_metadata_slot(request_data, _metadata_variable_name)
+        metadata: Final = normalized_metadata_slot(request_data, _metadata_variable_name)
 
         existing_tags: Final = metadata.get("tags")
         metadata["tags"] = LiteLLMProxyRequestSetup.merge_tags(
@@ -2637,7 +2697,7 @@ async def add_litellm_data_to_request(
     }
 
     safe_add_api_version_from_query_params(data, request)
-    _metadata_variable_name: Final = get_metadata_variable_name(request)
+    _metadata_variable_name: Final = get_metadata_variable_name(request, _REQUEST_FIELDS.validate_python(data))
     if data.get(_metadata_variable_name, None) is None:
         data[_metadata_variable_name] = {}
 
@@ -2974,17 +3034,7 @@ async def add_litellm_data_to_request(
             tags_to_add=tags,
         )
 
-    _caller_body_metadata: Final = data.get("metadata") if _metadata_variable_name != "metadata" else None
-    _caller_body_tags: Final = (
-        _caller_body_metadata.get("tags")
-        if isinstance(_caller_body_metadata, dict) and isinstance(_caller_body_metadata.get("tags"), list)
-        else None
-    )
-    if _caller_body_tags:
-        data[_metadata_variable_name]["tags"] = LiteLLMProxyRequestSetup.merge_tags(  # rebind-ok: matches file idiom
-            request_tags=data[_metadata_variable_name].get("tags"),
-            tags_to_add=_caller_body_tags,
-        )
+    LiteLLMProxyRequestSetup.merge_caller_body_tags(request_data=data, metadata_variable_name=_metadata_variable_name)
 
     # caller_tags: the tags the request's headers and body carry (x-litellm-tags, body "tags", and body
     # "metadata.tags" / "litellm_metadata.tags" read before the mapped tags are added below),

litellm/proxy/response_api_endpoints/endpoints.py

@@ -79,6 +79,7 @@ from litellm.proxy.hooks.responses_id_security import ResponsesIDSecurity, decry
 from litellm.proxy.litellm_pre_call_utils import (
     _CLIENT_PRICING_METADATA_FIELDS,  # pyright: ignore[reportPrivateUsage]  # the HTTP path's own strip list
     _UNTRUSTED_METADATA_CONTROL_FIELDS,  # pyright: ignore[reportPrivateUsage]  # the HTTP path's own strip list
+    is_chat_completions_body,
 )
 from litellm.proxy.pass_through_endpoints.llm_provider_handlers.batch_attribution import (
     request_tags_from_request_data,
@@ -213,13 +214,6 @@ def _normalize_tool_dialect(
     return {**data, **{key: value for key, value in replaceable if key in data}}
 
 
-def _is_chat_completions_body(data: Mapping[str, object]) -> bool:
-    messages: Final = data.get("messages")
-    if isinstance(messages, list) and messages:
-        return True
-    return "messages" in data and "input" not in data
-
-
 _CURSOR_THINKING_SEPARATOR: Final = "-thinking-"
 _CURSOR_FAST_SUFFIX: Final = "-fast"
 _CURSOR_THINKING_LEVELS: Final[frozenset[str]] = frozenset(get_args(REASONING_EFFORT))
@@ -261,7 +255,7 @@ def _resolve_cursor_model_variant(
     resolved: Final = {**data, "model": variant.base_model}
     if variant.reasoning_effort is None:
         return resolved
-    if _is_chat_completions_body(data):
+    if is_chat_completions_body(data):
         if "reasoning_effort" in data:
             return resolved
         return {**resolved, "reasoning_effort": variant.reasoning_effort}
@@ -646,7 +640,7 @@ async def cursor_chat_completions(
 
     raw_body: Final = await read_request_body(request=request)
 
-    if _is_chat_completions_body(raw_body):
+    if is_chat_completions_body(raw_body):
         # Genuine chat completions body (Cursor sends these for models whose BYOK it
         # already fixed); delegate so behavior matches /chat/completions exactly.
         # Keyed on messages CONTENT, not key presence: Cursor can send a null or

litellm/proxy/utils.py

@@ -250,7 +250,11 @@ from litellm.proxy.hooks.sensitive_data_routing import (  # noqa: F401, RUF100
     PROXY_SensitiveDataRoutingHandler,
     _PROXY_SensitiveDataRoutingHandler,  # pyright: ignore[reportPrivateUsage,reportUnusedImport]  # backwards-compatible package export
 )
-from litellm.proxy.litellm_pre_call_utils import LiteLLMProxyRequestSetup, add_guardrails_from_auth_metadata
+from litellm.proxy.litellm_pre_call_utils import (
+    LiteLLMProxyRequestSetup,
+    add_guardrails_from_auth_metadata,
+    normalized_metadata_slot,
+)
 from litellm.proxy.management_helpers.key_settings_audit import with_settings_updated_at
 from litellm.proxy.policy_engine.pipeline_executor import (
     PipelineExecutor,
@@ -3973,9 +3977,7 @@ class ProxyLogging:
             )
             request_data["litellm_logging_obj"] = litellm_logging_obj  # rebind-ok: lifted then popped by the caller
             request_data.update({REJECTED_BEFORE_REQUEST_SETUP_KEY: REJECTED_BEFORE_REQUEST_SETUP})
-            if "metadata" not in request_data:
-                request_data["metadata"] = {}
-            request_data["metadata"].update(user_api_key_logged_metadata)
+            normalized_metadata_slot(request_data, "metadata").update(user_api_key_logged_metadata)
 
         if litellm_logging_obj is not None:
             ## UPDATE LOGGING INPUT

tests/integration/providers/test_cursor_responses_wire.py

@@ -3,11 +3,14 @@ from __future__ import annotations
 import json
 import os
 import uuid
+from collections.abc import Mapping
+from hashlib import sha256
 from importlib.resources import files
 from typing import Final
 
+import httpx
 import pytest
-from integration._support.client import Gateway, Scenario
+from integration._support.client import Gateway, Scenario, eventually, list_value, object_value
 from integration._support.responses_vendor import same_response
 from integration._support.wire import Reply, Request, Wire, wire_server
 from integration._support.worker_readiness import wait_for_worker_readiness
@@ -38,6 +41,7 @@ _CHAT_SUFFIXES: Final[tuple[tuple[str, str], ...]] = (("", ""),) + tuple(
     (f"-thinking-{level}", level) for level in _CHAT_THINKING_LEVELS
 )
 _PROMPT: Final = "Inspect the requested change."
+_REQUEST_TAG: Final = "cursor-integration"
 _INPUT: Final = [{"role": "user", "content": [{"type": "input_text", "text": _PROMPT}]}]
 _CUSTOM_TOOL: Final = {
     "type": "custom",
@@ -107,16 +111,30 @@ def _stream(identity: str) -> tuple[bytes, ...]:
     ) + (b"data: [DONE]\n\n",)
 
 
-def _chat_completion(stream: bool) -> bytes | tuple[bytes, ...]:
+def _chat_completion(stream: bool, identity: str) -> bytes | tuple[bytes, ...]:
     if stream:
-        return (
-            b'data: {"id":"chat_cursor_1","object":"chat.completion.chunk","created":1,"model":"gpt-5","choices":[{"index":0,"delta":{"content":"Patch inspected."},"finish_reason":null}]}\n\n',
-            b'data: {"id":"chat_cursor_1","object":"chat.completion.chunk","created":1,"model":"gpt-5","choices":[{"index":0,"delta":{},"finish_reason":"stop"}]}\n\n',
-            b"data: [DONE]\n\n",
-        )
+        return tuple(
+            f"data: {json.dumps(chunk)}\n\n".encode()
+            for chunk in (
+                {
+                    "id": identity,
+                    "object": "chat.completion.chunk",
+                    "created": 1,
+                    "model": _MODEL,
+                    "choices": [{"index": 0, "delta": {"content": "Patch inspected."}, "finish_reason": None}],
+                },
+                {
+                    "id": identity,
+                    "object": "chat.completion.chunk",
+                    "created": 1,
+                    "model": _MODEL,
+                    "choices": [{"index": 0, "delta": {}, "finish_reason": "stop"}],
+                },
+            )
+        ) + (b"data: [DONE]\n\n",)
     return json.dumps(
         {
-            "id": "chat_cursor_1",
+            "id": identity,
             "object": "chat.completion",
             "created": 1,
             "model": _MODEL,
@@ -133,11 +151,12 @@ def _chat_completion(stream: bool) -> bytes | tuple[bytes, ...]:
     ).encode()
 
 
-def _deployment(scenario: Scenario, wire: Wire) -> str:
+def _deployment(scenario: Scenario, wire: Wire, **pricing: JsonValue) -> str:
     model: Final = scenario.model(
         model=f"openai/{_MODEL}",
         api_key=_API_KEY,
         api_base=f"{wire.url}/v1",
+        **pricing,
     )
     wait_for_worker_readiness(scenario.gateway, model, 1, _PROXY_WORKERS)
     return model
@@ -167,7 +186,7 @@ def test_cursor_responses_input_uses_responses_wire_and_chat_output(
             assert request.method == "POST"
             assert request.headers["authorization"] == f"Bearer {_API_KEY}", dict(request.headers)
             if request.target == "/v1/chat/completions":
-                completion: Final = _chat_completion(stream)
+                completion: Final = _chat_completion(stream, raw_id)
                 return Reply(
                     content_type="text/event-stream" if stream else "application/json",
                     chunks=completion if isinstance(completion, tuple) else None,
@@ -175,7 +194,7 @@ def test_cursor_responses_input_uses_responses_wire_and_chat_output(
                 )
             assert request.target == "/v1/responses", request.target
             body: Final = _JSON_OBJECT.validate_json(request.body)
-            assert {key: value for key, value in body.items() if key != "metadata"} == {
+            assert body == {
                 "model": _MODEL,
                 "input": _INPUT,
                 **reasoning,
@@ -259,41 +278,69 @@ def test_cursor_responses_input_uses_responses_wire_and_chat_output(
             assert [request.target for request in drain_contract_requests(wire)] == ["/v1/responses"]
 
 
-def test_cursor_responses_body_carries_no_proxy_metadata(gateway: Gateway) -> None:
-    pytest.skip(
-        "BUG: /cursor/chat/completions forwards proxy-internal metadata (key hash, team, user, client ip, user agent) "
-        "to the provider in the Responses body"
-    )
+@pytest.mark.parametrize(
+    "client_metadata", ({}, {"cursor_conversation": "integration"}), ids=("no_client_metadata", "client_metadata")
+)
+@pytest.mark.parametrize("stream", (False, True))
+def test_cursor_responses_body_sends_only_client_metadata_and_bills_the_key(
+    gateway: Gateway,
+    stream: bool,
+    client_metadata: Mapping[str, JsonValue],
+) -> None:
     raw_id: Final = f"resp_cursor_metadata_{uuid.uuid4().hex}"
+    alias: Final = f"integration-cursor-{uuid.uuid4().hex}"
+    sent_metadata: Final = {"metadata": client_metadata} if client_metadata else {}
 
     def respond(request: Request) -> Reply:
         if request.method == "GET" and request.target == "/v1/models":
             return model_discovery_reply(_MODEL)
         assert request.method == "POST" and request.target == "/v1/responses", request.target
+        if stream:
+            return Reply(content_type="text/event-stream", chunks=_stream(raw_id))
         return Reply(body=json.dumps(_response(raw_id)).encode())
 
     with wire_server(respond) as wire, gateway.scenario() as scenario:
         model: Final = _deployment(scenario, wire)
+        key: Final = scenario.key(key_alias=alias)
+        hashed_key: Final = sha256(key.encode()).hexdigest()
         response: Final = gateway.request(
             "POST",
             "/cursor/chat/completions",
             {
-                "model": f"{model}-thinking-high",
+                "model": model,
                 "input": _INPUT,
                 "messages": [],
                 "tools": [_CUSTOM_TOOL],
+                "stream": stream,
+                **sent_metadata,
             },
+            key=key,
         )
         assert response.status_code == 200, response.text
         requests: Final = drain_contract_requests(wire)
         assert len(requests) == 1, requests
-        body: Final = _JSON_OBJECT.validate_json(requests[0].body)
-        assert body == {
+        assert _JSON_OBJECT.validate_json(requests[0].body) == {
             "model": _MODEL,
             "input": _INPUT,
-            "reasoning": {"effort": "high"},
             "tools": [_CUSTOM_TOOL],
+            "stream": stream,
+            **sent_metadata,
         }, requests[0].body
+        (row,) = eventually(
+            lambda: gateway.rows(
+                'SELECT call_type, spend, metadata FROM "LiteLLM_SpendLogs" WHERE api_key = %s', (hashed_key,)
+            ),
+            lambda rows: len(rows) == 1,
+            seconds=70,
+        )
+        assert row["call_type"] == "aresponses", row
+        assert object_value(row["metadata"])["user_api_key_alias"] == alias, row
+        assert isinstance(row["spend"], float) and row["spend"] > 0, row
+        eventually(
+            lambda: gateway.rows('SELECT spend FROM "LiteLLM_VerificationToken" WHERE token = %s', (hashed_key,)),
+            lambda tokens: len(tokens) == 1 and tokens[0]["spend"] == pytest.approx(row["spend"]),
+            seconds=70,
+        )
 
 
 def test_cursor_stream_reports_usage_when_the_client_asks_for_it(gateway: Gateway) -> None:
@@ -341,10 +388,12 @@ def test_cursor_messages_body_uses_chat_completions_wire(
     suffix: str,
     reasoning_effort: str,
 ) -> None:
+    chat_id: Final = f"chat_cursor_{uuid.uuid4().hex}"
+
     def respond(request: Request) -> Reply:
         if request.method == "GET" and request.target == "/v1/models":
             return model_discovery_reply(_MODEL)
-        completion: Final = _chat_completion(stream)
+        completion: Final = _chat_completion(stream, chat_id)
         return Reply(
             content_type="text/event-stream" if stream else "application/json",
             chunks=completion if isinstance(completion, tuple) else None,
@@ -367,6 +416,7 @@ def test_cursor_messages_body_uses_chat_completions_wire(
                 "stream": stream,
             },
             key=key,
+            headers={"x-litellm-tags": _REQUEST_TAG},
         )
         assert response.status_code == 200, response.text
         if stream:
@@ -393,7 +443,7 @@ def test_cursor_messages_body_uses_chat_completions_wire(
             payload: Final = _JSON_OBJECT.validate_json(response.content)
             identity: Final = payload.get("id")
             created: Final = payload.get("created")
-            assert isinstance(identity, str) and same_response(identity, "chat_cursor_1"), response.text
+            assert isinstance(identity, str) and same_response(identity, chat_id), response.text
             assert isinstance(created, int) and created > 0, response.text
             assert payload == {
                 "id": identity,
@@ -456,3 +506,72 @@ def test_cursor_messages_body_uses_chat_completions_wire(
             **({"stream_options": {"include_usage": True}} if stream else {}),
             **({"reasoning_effort": reasoning_effort} if reasoning_effort else {}),
         }, requests[0].body
+        (row,) = eventually(
+            lambda: gateway.rows(
+                'SELECT call_type, team_id, request_tags FROM "LiteLLM_SpendLogs" WHERE api_key = %s',
+                (sha256(key.encode()).hexdigest(),),
+            ),
+            lambda rows: len(rows) == 1,
+            seconds=70,
+        )
+        assert (row["call_type"], row["team_id"]) == ("acompletion", team), row
+        assert _REQUEST_TAG in list_value(row["request_tags"]), row
+
+
+@pytest.mark.parametrize(
+    ("body_shape", "metadata_as_json_string"), (("messages", False), ("input", False), ("input", True))
+)
+def test_cursor_body_keeps_client_and_key_tags_and_enforces_the_client_tag_budget(
+    gateway: Gateway, body_shape: str, metadata_as_json_string: bool
+) -> None:
+    chat_id: Final = f"chat_cursor_{uuid.uuid4().hex}"
+    response_id: Final = f"resp_cursor_tags_{uuid.uuid4().hex}"
+    budget_tag: Final = f"cursor-tag-budget-{uuid.uuid4().hex}"
+    key_tag: Final = f"cursor-key-tag-{uuid.uuid4().hex}"
+    client_metadata: Final = {"tags": [budget_tag]}
+
+    def respond(request: Request) -> Reply:
+        if request.method == "GET" and request.target == "/v1/models":
+            return model_discovery_reply(_MODEL)
+        if request.target == "/v1/responses":
+            return Reply(body=json.dumps(_response(response_id)).encode())
+        completion: Final = _chat_completion(False, chat_id)
+        return Reply(body=completion if isinstance(completion, bytes) else b"")
+
+    def delete_tag() -> None:
+        gateway.post("/tag/delete", {"name": budget_tag})
+
+    with wire_server(respond) as wire, gateway.scenario() as scenario:
+        model: Final = _deployment(scenario, wire, input_cost_per_token=0.01, output_cost_per_token=0.01)
+        key: Final = scenario.key(models=[model], metadata={"tags": [key_tag]})
+        gateway.post("/tag/new", {"name": budget_tag, "max_budget": 0.0001})
+        scenario.cleanups.callback(delete_tag)
+
+        def tagged_chat(text: str) -> httpx.Response:
+            return gateway.request(
+                "POST",
+                "/cursor/chat/completions",
+                {
+                    "model": model,
+                    body_shape: [{"role": "user", "content": text}],
+                    "metadata": json.dumps(client_metadata) if metadata_as_json_string else client_metadata,
+                },
+                key=key,
+            )
+
+        first: Final = tagged_chat("first tagged chat")
+        assert first.status_code == 200, first.text
+        (row,) = eventually(
+            lambda: gateway.rows(
+                'SELECT request_tags FROM "LiteLLM_SpendLogs" WHERE api_key = %s',
+                (sha256(key.encode()).hexdigest(),),
+            ),
+            lambda rows: len(rows) == 1,
+            seconds=70,
+        )
+        assert {budget_tag, key_tag} <= set(list_value(row["request_tags"])), row
+        blocked: Final = eventually(
+            lambda: tagged_chat("tag budget probe"), lambda response: response.status_code != 200, seconds=70
+        )
+        assert blocked.status_code == 422, blocked.text
+        assert "budget" in blocked.text.lower(), blocked.text

tests/unit/integrations/test_custom_guardrail.py

@@ -3699,6 +3699,20 @@ def test_get_guardrail_from_metadata() -> None:
     ) == [{"test-guardrail": {"extra_body": {"key": "value"}}}]
 
 
+
+@pytest.mark.parametrize(
+    "caller_metadata",
+    [{"guardrails": []}, {"guardrails": ["not-a-guardrail"]}, {"guardrails": None}],
+)
+def test_caller_metadata_guardrails_never_hide_the_proxy_guardrails_in_litellm_metadata(caller_metadata: dict) -> None:
+    guardrail: Final = CustomGuardrail(
+        guardrail_name="key-guardrail", event_hook=GuardrailEventHooks.pre_call, default_on=False
+    )
+    request_data: Final = {"metadata": caller_metadata, "litellm_metadata": {"guardrails": ["key-guardrail"]}}
+
+    assert guardrail.should_run_guardrail(request_data, GuardrailEventHooks.pre_call) is True
+
+
 def test_guardrail_is_in_requested_guardrails() -> None:
     guardrail: Final = CustomGuardrail(guardrail_name="test-guardrail")
 

tests/unit/proxy/hooks/test_parallel_request_limiter_v3.py

@@ -2591,7 +2591,8 @@ async def test_agent_session_rate_limit_skipped_without_session_id():
 
 
 @pytest.mark.asyncio
-async def test_agent_rate_limit_from_metadata_agent_id():
+@pytest.mark.parametrize("metadata_field", ("metadata", "litellm_metadata"))
+async def test_agent_rate_limit_from_metadata_agent_id(metadata_field):
     """
     Test that agent rate limits work when agent_id comes from
     request metadata (header) rather than from the API key.
@@ -2639,7 +2640,7 @@ async def test_agent_rate_limit_from_metadata_agent_id():
             cache=local_cache,
             data={
                 "model": "gpt-4",
-                "metadata": {"agent_id": _agent_id},
+                metadata_field: {"agent_id": _agent_id},
             },
             call_type="",
         )

tests/unit/proxy/hooks/test_proxy_track_cost_callback.py

@@ -623,6 +623,56 @@ async def test_async_post_call_failure_hook_reads_used_client_oauth_token_from_t
     assert json.loads(payload["metadata"])["used_client_oauth_token"] is expected
 
 
+
+@pytest.mark.asyncio
+@pytest.mark.parametrize(
+    "request_route, body",
+    [
+        (
+            "/cursor/chat/completions",
+            {
+                "input": "Hello",
+                "metadata": {"requester_ip_address": "203.0.113.9", "user_agent": "spoofed"},
+                "litellm_metadata": {"requester_ip_address": "127.0.0.1", "user_agent": "Cursor/1.0"},
+            },
+        ),
+        (
+            "/v1/chat/completions",
+            {
+                "messages": [{"role": "user", "content": "Hello"}],
+                "metadata": {"requester_ip_address": "127.0.0.1", "user_agent": "Cursor/1.0"},
+                "litellm_metadata": {"requester_ip_address": "203.0.113.9", "user_agent": "spoofed"},
+            },
+        ),
+    ],
+)
+async def test_async_post_call_failure_hook_logs_the_proxy_stamped_ip_and_user_agent(request_route: str, body: dict):
+    request_data = {
+        "model": "gpt-4o",
+        "proxy_server_request": {"request_id": "test_request_id"},
+        **body,
+    }
+
+    with patch(
+        "litellm.proxy.db.db_spend_update_writer.DBSpendUpdateWriter.update_database",
+        new_callable=AsyncMock,
+    ) as mock_update_database:
+        await ProxyDBLogger().async_post_call_failure_hook(
+            request_data=request_data,
+            original_exception=Exception("invalid api key"),
+            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 payload["requester_ip_address"] == "127.0.0.1"
+    assert json.loads(payload["metadata"])["user_agent"] == "Cursor/1.0"
+
+
 @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

tests/unit/proxy/response_api_endpoints/test_endpoints.py

@@ -3938,7 +3938,7 @@ class TestCursorInputArmFlattening:
 
 class TestChatCompletionsBodyDetection:
     def test_routing_matrix(self):
-        from litellm.proxy.response_api_endpoints.endpoints import _is_chat_completions_body
+        from litellm.proxy.litellm_pre_call_utils import is_chat_completions_body as _is_chat_completions_body
 
         assert _is_chat_completions_body({"messages": [{"role": "user", "content": "hi"}]}) is True
         assert _is_chat_completions_body({"messages": [{"role": "user", "content": "hi"}], "input": []}) is True

tests/unit/proxy/test_common_request_processing.py

@@ -9711,6 +9711,40 @@ async def test_saved_weights_override_caller_input_and_preserve_key_precedence(
     assert logging.pre_call_hook.call_args.kwargs["data"].get("_router_weights") == expected
 
 
+def _hook_data(**kwargs: object) -> object:
+    return kwargs["data"]
+
+
+@pytest.mark.asyncio
+@pytest.mark.parametrize("prompt, proxy_field, client_field", [
+    ({"input": "hi"}, "litellm_metadata", "metadata"),
+    ({"messages": [{"role": "user", "content": "hi"}]}, "metadata", "litellm_metadata"),
+])
+async def test_cursor_route_writes_proxy_fields_only_to_the_field_its_body_shape_picks(
+    prompt: dict[str, str | list[dict[str, str]]],
+    proxy_field: str,
+    client_field: str,
+) -> None:
+    from litellm.proxy import proxy_server
+
+    logging: Final = MagicMock(spec=ProxyLogging)
+    logging.pre_call_hook = AsyncMock(side_effect=_hook_data)
+    processor: Final = ProxyBaseLLMRequestProcessing(data={"model": "gpt-x", "metadata": {"client": "cursor"}, **prompt})
+    data, _ = await processor.common_processing_pre_call_logic(
+        request=Request({"type": "http", "method": "POST", "path": "/cursor/chat/completions", "headers": []}),
+        general_settings={},
+        user_api_key_dict=ProxyUserAPIKeyAuth(api_key="hash"),
+        proxy_logging_obj=logging,
+        proxy_config=proxy_server.ProxyConfig(),
+        route_type="acompletion",
+        logging_auth=ProxyUserAPIKeyAuth(api_key="logging-hash", key_alias="logging-alias"),
+    )
+    assert data[proxy_field]["user_api_key_alias"] == "logging-alias"
+    assert "queue_time_seconds" in data[proxy_field]
+    assert "user_api_key_alias" not in data.get(client_field, {})
+    assert "queue_time_seconds" not in data.get(client_field, {})
+    assert data["metadata"]["client"] == "cursor"
+
 class TestPerRequestModelGroupAlias:
     """``router_settings.model_group_alias`` on a key or team has to be resolved
     by the proxy: the Router resolves aliases from its own shared instance

tests/unit/proxy/test_litellm_pre_call_utils.py

@@ -121,6 +121,23 @@ class TestGetMetadataVariableName:
         request = self._make_request("/chat/completions")
         assert get_metadata_variable_name(request) == "metadata"
 
+    @pytest.mark.parametrize(
+        "body, expected",
+        [
+            ({"messages": [{"role": "user", "content": "hi"}]}, "metadata"),
+            ({"messages": []}, "metadata"),
+            ({"input": [{"role": "user", "content": "hi"}]}, "litellm_metadata"),
+            ({"input": "hi", "messages": []}, "litellm_metadata"),
+        ],
+    )
+    def test_cursor_route_picks_the_metadata_field_by_body_shape(self, body, expected):
+        request = self._make_request("/cursor/chat/completions")
+        assert get_metadata_variable_name(request, body) == expected
+
+    def test_cursor_route_without_a_body_keeps_the_route_answer(self):
+        request = self._make_request("/cursor/chat/completions")
+        assert get_metadata_variable_name(request) == "metadata"
+
     def test_returns_metadata_for_completions(self):
         request = self._make_request("/v1/completions")
         assert get_metadata_variable_name(request) == "metadata"
@@ -681,6 +698,45 @@ async def test_add_litellm_data_to_request_rejects_non_object_metadata(field, va
     assert field not in data
 
 
+@pytest.mark.asyncio
+@pytest.mark.parametrize("route", ["/v1/chat/completions", "/v1/responses", "/cursor/chat/completions"])
+@pytest.mark.parametrize("value, received_type", [("junk", "a string"), (5, "an integer"), ([1], "an array")])
+async def test_invalid_litellm_metadata_answers_400_when_metadata_carries_tags(route, value, received_type):
+    from litellm.proxy.auth.auth_checks import common_checks
+    from litellm.proxy.utils import ProxyLogging
+
+    data = {"model": "gpt-4o", "input": "hi", "metadata": {"tags": ["client-tag"]}, "litellm_metadata": value}
+    request = _batches_request_mock()
+    await common_checks(
+        request_body=data,
+        team_object=None,
+        user_object=None,
+        end_user_object=None,
+        global_proxy_spend=None,
+        general_settings={},
+        route=route,
+        llm_router=None,
+        proxy_logging_obj=ProxyLogging(user_api_key_cache=None),
+        valid_token=UserAPIKeyAuth(api_key="hashed-key"),
+        request=request,
+    )
+
+    with pytest.raises(ProxyException) as exc_info:
+        await add_litellm_data_to_request(
+            data=data,
+            request=request,
+            user_api_key_dict=UserAPIKeyAuth(api_key="hashed-key"),
+            proxy_config=MagicMock(),
+            general_settings={},
+            version="test-version",
+        )
+
+    assert exc_info.value.code == "400"
+    assert exc_info.value.message == (
+        f"Invalid type for 'litellm_metadata': expected an object, but got {received_type} instead."
+    )
+
+
 @pytest.mark.asyncio
 async def test_add_litellm_data_to_request_removes_every_invalid_metadata_field_before_raising():
     """When both fields are invalid, the raise for the first must not leave the
@@ -11098,3 +11154,15 @@ def test_mapped_baggage_tags_keep_non_string_client_tags_as_sent():
     data: Final[dict[str, object]] = {"metadata": {"tags": [1, {"team": "x"}, "client-tag", "client-tag"]}}
     LiteLLMProxyRequestSetup.apply_authenticated_baggage_tags(request, data)
     assert data["metadata"]["tags"] == [1, {"team": "x"}, "client-tag", "client-tag", "tenant:a"]
+
+
+@pytest.mark.parametrize("caller_metadata", ({"tags": ["client-tag"]}, json.dumps({"tags": ["client-tag"]})))
+def test_caller_tags_reach_litellm_metadata_whether_metadata_is_a_dict_or_a_json_string(caller_metadata):
+    data: Final[dict[str, object]] = {
+        "input": "hi",
+        "metadata": caller_metadata,
+        "litellm_metadata": {"tags": ["key-tag"]},
+    }
+    LiteLLMProxyRequestSetup.merge_caller_body_tags(request_data=data)
+    assert set(data["litellm_metadata"]["tags"]) == {"key-tag", "client-tag"}
+    assert data["metadata"] == caller_metadata

tests/unit/proxy/utils/proxy_logging/test_post_call_failure_hook.py

@@ -4,6 +4,7 @@ and ``_handle_logging_proxy_only_error``."""
 from __future__ import annotations
 
 import asyncio
+import json
 from collections.abc import Callable
 from datetime import datetime
 from types import MappingProxyType
@@ -1192,3 +1193,31 @@ async def test_handle_logging_proxy_only_path_flags_requests_that_died_before_re
         blocked_by_guardrail.get(REJECTED_BEFORE_REQUEST_SETUP_KEY) is REJECTED_BEFORE_REQUEST_SETUP,
         blocked_by_guardrail["litellm_call_id"],
     ) == (True, "client-supplied", False, "call-1")
+
+
+@pytest.mark.asyncio
+async def test_auth_failure_on_a_responses_body_with_a_json_string_metadata_is_logged_against_the_key(
+    proxy_logging, monkeypatch
+):
+    from litellm.proxy import proxy_server
+
+    recorded: list[dict] = []
+
+    class _RecordingLogger(CustomLogger):
+        async def async_log_failure_event(self, kwargs, response_obj, start_time, end_time):
+            recorded.append(kwargs)
+
+    monkeypatch.setattr(proxy_server, "llm_router", None)
+    monkeypatch.setattr(litellm, "callbacks", [_RecordingLogger()])
+    proxy_logging.alert_types = []
+
+    await proxy_logging.post_call_failure_hook(
+        request_data={"model": "internal-model", "input": "hi", "metadata": json.dumps({"tags": ["checkout"]})},
+        original_exception=litellm.BudgetExceededError(current_cost=1.0, max_budget=0.5),
+        user_api_key_dict=UserAPIKeyAuth(api_key="sk-hashed", key_alias="checkout-key", request_route="/v1/responses"),
+        error_type=ProxyErrorTypes.auth_error,
+        route="/v1/responses",
+    )
+
+    assert len(recorded) == 1
+    assert recorded[0]["standard_logging_object"]["metadata"]["user_api_key_alias"] == "checkout-key"