fix(logging): keep the proxy's own budget rejection an expected client error

The auth handler stamps the requested model's provider onto BudgetExceededError before logging it, which made a key-over-budget 429 look provider-originated and regain its traceback (and an OTel stack_trace) after the provider 4xx carve-out. Any exception whose unified rate-limit category names litellm's own limiter is now a proxy rejection, matching the HTTPException rule.

litellm/litellm_core_utils/core_helpers.py

@@ -58,7 +58,18 @@ def safe_divide(
     return numerator / denominator
 
 
+def _is_litellm_limit_rejection(exception: BaseException) -> bool:
+    from litellm.exceptions import RateLimitErrorCategory
+
+    litellm_limit_categories: Final = frozenset(
+        (RateLimitErrorCategory.LITELLM_RATE_LIMIT.value, RateLimitErrorCategory.LITELLM_BATCH_RATE_LIMIT.value)
+    )
+    return getattr(exception, "category", None) in litellm_limit_categories
+
+
 def _is_proxy_rejection(exception: BaseException) -> bool:
+    if _is_litellm_limit_rejection(exception):
+        return True
     try:
         from starlette.exceptions import HTTPException
     except ImportError:
@@ -85,7 +96,10 @@ def is_expected_client_error(exception: BaseException | None) -> bool:
     ``llm_provider``, and the raw ``BaseLLMException`` that provider handlers
     raise before mapping (the /v1/messages route surfaces it as-is) is one too.
     The proxy's own limiters raise ``HTTPException`` subclasses that also carry
-    an ``llm_provider``, so any ``HTTPException`` stays a proxy rejection.
+    an ``llm_provider``, so any ``HTTPException`` stays a proxy rejection, and
+    so does any exception whose unified rate-limit ``category`` names litellm's
+    own limiter (``BudgetExceededError`` is a plain ``Exception`` that the auth
+    handler decorates with the requested model's provider).
 
     ProxyException stores the status on .code (as a str), HTTPException and
     litellm exceptions on .status_code.

tests/test_litellm/litellm_core_utils/test_core_helpers.py

@@ -311,3 +311,26 @@ class TestIsExpectedClientError:
                 self.llm_provider = ""
 
         assert is_expected_client_error(RouterRejection()) is True
+
+    def test_budget_rejection_decorated_with_provider_is_expected(self):
+        """The auth handler stamps the requested model's provider onto the proxy's
+        own BudgetExceededError before logging it, which must not turn a key-over-budget
+        429 into a provider error that keeps its traceback."""
+        from litellm.exceptions import BudgetExceededError, RateLimitError, RateLimitErrorCategory
+        from litellm.litellm_core_utils.core_helpers import is_expected_client_error
+
+        over_budget = BudgetExceededError(current_cost=0.01, max_budget=0.0, llm_provider="anthropic")
+        assert over_budget.llm_provider == "anthropic"
+        assert is_expected_client_error(over_budget) is True
+
+        litellm_limit = RateLimitError(
+            message="key over rpm", llm_provider="anthropic", model="claude-haiku-4-5",
+            category=RateLimitErrorCategory.LITELLM_RATE_LIMIT,
+        )
+        assert is_expected_client_error(litellm_limit) is True
+
+        vendor_limit = RateLimitError(
+            message="rate limited upstream", llm_provider="anthropic", model="claude-haiku-4-5",
+            category=RateLimitErrorCategory.VENDOR_RATE_LIMIT,
+        )
+        assert is_expected_client_error(vendor_limit) is False

tests/test_litellm/litellm_core_utils/test_litellm_logging.py

@@ -5746,6 +5746,19 @@ def test_get_error_information_keeps_traceback_for_unmapped_provider_4xx():
     assert "test_litellm_logging" in result["traceback"]
 
 
+def test_get_error_information_skips_traceback_for_budget_rejection_with_provider():
+    """A key-over-budget 429 is the proxy's own rejection even after the auth
+    handler stamps the requested model's provider onto it, so it stays cheap."""
+    from litellm.litellm_core_utils.litellm_logging import StandardLoggingPayloadSetup
+
+    assert litellm.log_client_error_tracebacks is False
+    over_budget = _raise_and_catch(litellm.BudgetExceededError(current_cost=0.01, max_budget=0.0, llm_provider="anthropic"))
+    result = StandardLoggingPayloadSetup.get_error_information(over_budget)
+    assert result["error_code"] == "429"
+    assert result["llm_provider"] == "anthropic"
+    assert result["traceback"] == ""
+
+
 def test_failure_handler_helper_fn_builds_payload_once_per_exception():
     """Regression for LIT-6043: async and sync failure handlers both call
     _failure_handler_helper_fn for the same failed request; the standardized