From eea9bb1497d69ed16fcc022a51bc81d6048da735 Mon Sep 17 00:00:00 2001
From: mateo-berri <277851410+mateo-berri@users.noreply.github.com>
Date: Sat, 1 Aug 2026 17:13:15 -0700
Subject: [PATCH] chore(lint): use a PEP 604 union for the flat tool_choice
 helper (UP007)

---
 .../litellm_responses_transformation/transformation.py          | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/litellm/completion_extras/litellm_responses_transformation/transformation.py b/litellm/completion_extras/litellm_responses_transformation/transformation.py
index 1cc1e88f1fa..79a4620dc80 100644
--- a/litellm/completion_extras/litellm_responses_transformation/transformation.py
+++ b/litellm/completion_extras/litellm_responses_transformation/transformation.py
@@ -141,7 +141,7 @@ def _tool_call_dict_from_output_item(item: Mapping[str, Any], index: int) -> _Ch
     return tool_call_dict
 
 
-def _flat_responses_tool_choice(choice_type: str, name: str) -> Union[ToolChoiceFunctionParam, ToolChoiceCustomParam]:
+def _flat_responses_tool_choice(choice_type: str, name: str) -> ToolChoiceFunctionParam | ToolChoiceCustomParam:
     if choice_type == "custom":
         return ToolChoiceCustomParam(type="custom", name=name)
     return ToolChoiceFunctionParam(type="function", name=name)