chore(proxy): log stripped pricing fields at debug for operator visibility

Operators upgrading would otherwise see client-supplied pricing overrides
silently stop applying with no diagnostic. Emit a debug-level line listing
the dropped fields and pointing at the opt-in flag when any are stripped;
stay silent on the no-op path so the log isn't filled with noise.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

litellm/proxy/litellm_pre_call_utils.py

@@ -240,16 +240,31 @@ def _strip_client_pricing_overrides(data: Dict[str, Any]) -> None:
     """Drop pricing overrides from the request body and any metadata variant.
 
     Skipped only when the calling key/team carries
-    ``allow_client_pricing_override: True`` in its metadata.
+    ``allow_client_pricing_override: True`` in its metadata. Emits a
+    ``debug``-level log line naming the dropped fields so operators can
+    trace why a client-supplied pricing override stopped being applied
+    (otherwise the strip is invisible from the caller's perspective).
     """
+    stripped: List[str] = []
     for field in _CLIENT_PRICING_CONTROL_FIELDS:
-        data.pop(field, None)
+        if field in data:
+            stripped.append(field)
+            data.pop(field, None)
     for metadata_key in ("metadata", "litellm_metadata"):
         metadata = data.get(metadata_key)
         if not isinstance(metadata, dict):
             continue
         for field in _CLIENT_PRICING_METADATA_FIELDS:
-            metadata.pop(field, None)
+            if field in metadata:
+                stripped.append(f"{metadata_key}.{field}")
+                metadata.pop(field, None)
+    if stripped:
+        verbose_proxy_logger.debug(
+            "Stripped client-supplied pricing fields from request body: %s. "
+            "Set `allow_client_pricing_override: true` on the key or team "
+            "metadata to keep these values.",
+            ", ".join(stripped),
+        )
 
 
 def _get_metadata_variable_name(request: Request) -> str:

tests/test_litellm/proxy/test_pricing_field_strip.py

@@ -130,6 +130,41 @@ class TestStripClientPricingOverrides:
     def test_metadata_field_set_contains_model_info(self):
         assert "model_info" in _CLIENT_PRICING_METADATA_FIELDS
 
+    def test_strip_emits_debug_log_listing_dropped_fields(self, caplog):
+        # Operators need a paper trail so they can diagnose why a previously
+        # working override stopped applying after the strip landed.
+        import logging
+
+        from litellm._logging import verbose_proxy_logger
+
+        verbose_proxy_logger.setLevel(logging.DEBUG)
+        with caplog.at_level(logging.DEBUG, logger=verbose_proxy_logger.name):
+            _strip_client_pricing_overrides(
+                {
+                    "model": "gpt-4",
+                    "input_cost_per_token": 0.0,
+                    "metadata": {"model_info": {"output_cost_per_token": 0.0}},
+                }
+            )
+        log_text = " ".join(record.getMessage() for record in caplog.records)
+        assert "input_cost_per_token" in log_text
+        assert "metadata.model_info" in log_text
+        assert "allow_client_pricing_override" in log_text
+
+    def test_strip_does_not_log_when_no_fields_present(self, caplog):
+        # No-op strips must stay silent so the log isn't filled with noise on
+        # every legitimate request.
+        import logging
+
+        from litellm._logging import verbose_proxy_logger
+
+        verbose_proxy_logger.setLevel(logging.DEBUG)
+        with caplog.at_level(logging.DEBUG, logger=verbose_proxy_logger.name):
+            _strip_client_pricing_overrides({"model": "gpt-4", "temperature": 0.7})
+        assert not any(
+            "pricing" in record.getMessage().lower() for record in caplog.records
+        )
+
 
 @pytest.mark.asyncio
 async def test_add_litellm_data_to_request_strips_root_pricing_fields():