From 2eab418cf94739835a058fb70614602d6692788d Mon Sep 17 00:00:00 2001
From: Sangsiva <101570025+Sangsiva@users.noreply.github.com>
Date: Mon, 21 Sep 2026 15:42:35 +0800
Subject: [PATCH] fix(anthropic): annotate return type of identity-strip
 staticmethod

Restores the ANN205 strict-rule budget: the new helper is a @staticmethod
and must carry a return annotation like its billing-header sibling gate.
---
 .../experimental_pass_through/messages/transformation.py        | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/litellm/llms/anthropic/experimental_pass_through/messages/transformation.py b/litellm/llms/anthropic/experimental_pass_through/messages/transformation.py
index 641f7410126..f754c558c87 100644
--- a/litellm/llms/anthropic/experimental_pass_through/messages/transformation.py
+++ b/litellm/llms/anthropic/experimental_pass_through/messages/transformation.py
@@ -137,7 +137,7 @@ class AnthropicMessagesConfig(BaseAnthropicMessagesConfig):
         return False
 
     @staticmethod
-    def _strip_claude_code_identity_from_system(system_param):
+    def _strip_claude_code_identity_from_system(system_param) -> str | list | None:
         """
         Strip Claude Code's self-identification sentence from system parameter.