refactor: clear fresh tech debt from the last 24 hours (2026-09-17)

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

litellm/proxy/_experimental/mcp_server/bridge_token_flow.py

@@ -86,8 +86,8 @@ async def oauth_authorization_uses_gateway_credential(request: Request) -> bool:
 
 
 async def _opaque_bearer_is_gateway_credential(token: str) -> bool:
-    from litellm.proxy._experimental.mcp_server.outbound_credentials.envelope import (
-        is_envelope,  # noqa: PLC0415  # envelope imports bridge types
+    from litellm.proxy._experimental.mcp_server.outbound_credentials.envelope import (  # noqa: PLC0415  # envelope imports bridge types
+        is_envelope,
         is_refresh_envelope,
     )
     from litellm.proxy._types import hash_token  # noqa: PLC0415  # proxy import cycle

litellm/proxy/common_request_processing.py

@@ -2241,7 +2241,7 @@ class ProxyBaseLLMRequestProcessing:
         return fallbacks if isinstance(fallbacks, list) and fallbacks else None
 
     @staticmethod
-    def _resolve_fallback_models(model: str, fallbacks: list) -> list | None:
+    def _resolve_fallback_models(model: str, fallbacks: list) -> list[str] | None:
         from litellm.router_utils.fallback_event_handlers import get_fallback_model_group
 
         fallback_model_group, generic_fallback_idx = get_fallback_model_group(

litellm/proxy/guardrails/guardrail_initializers.py

@@ -120,7 +120,7 @@ def initialize_presidio(litellm_params: LitellmParams, guardrail: Guardrail) ->
         _OPTIONAL_PresidioPIIMasking,
     )
 
-    explicit_filter_scope: Final = getattr(litellm_params, "presidio_filter_scope", None)
+    explicit_filter_scope: Final = litellm_params.presidio_filter_scope
     filter_scope: Final = explicit_filter_scope or ("input" if _is_mcp_only_mode(litellm_params.mode) else "both")
     run_input: Final = filter_scope in ("input", "both")
     run_output: Final = filter_scope in ("output", "both")

litellm/proxy/litellm_pre_call_utils.py

@@ -137,7 +137,7 @@ def add_otel_trace_id_to_request(
         return
     data["litellm_trace_id"] = trace_id  # rebind-ok: data is an out-param
     if isinstance(metadata, dict):
-        metadata["trace_id"] = trace_id  # rebind-ok: metadata is the request's own out-param dict
+        metadata["trace_id"] = trace_id
 
 
 def _session_id_from_baggage(baggage: str) -> str | None: