diff --git a/litellm/llms/anthropic/pass_through/messages/transformation.py b/litellm/llms/anthropic/pass_through/messages/transformation.py
index 4869acba40c..effc257c075 100644
--- a/litellm/llms/anthropic/pass_through/messages/transformation.py
+++ b/litellm/llms/anthropic/pass_through/messages/transformation.py
@@ -1,5 +1,5 @@
 from collections.abc import AsyncIterator, Mapping, Sequence
-from typing import ClassVar, Final
+from typing import ClassVar, Final, cast
 
 import httpx
 
@@ -429,8 +429,10 @@ class AnthropicMessagesConfig(BaseAnthropicMessagesConfig):
                     ),
                     status_code=400,
                 )
-            existing_output_config: Final = optional_params.get("output_config")
-            explicit_effort: Final = AnthropicMessagesConfig._explicit_output_config_effort(existing_output_config)
+            existing_output_config: Final = cast(  # cast-ok: optional_params is an untyped dict
+                object, optional_params.get("output_config")
+            )
+            explicit_effort: Final = AnthropicMessagesConfig.explicit_output_config_effort(existing_output_config)
             resolved_effort: Final = (
                 explicit_effort
                 if explicit_effort is not None
@@ -446,7 +448,7 @@ class AnthropicMessagesConfig(BaseAnthropicMessagesConfig):
             )
 
     @staticmethod
-    def _explicit_output_config_effort(output_config: object) -> str | None:
+    def explicit_output_config_effort(output_config: object) -> str | None:
         match output_config:
             case {"effort": str() as effort}:
                 return effort
diff --git a/litellm/llms/bedrock/messages/invoke_transformations/anthropic_claude3_transformation.py b/litellm/llms/bedrock/messages/invoke_transformations/anthropic_claude3_transformation.py
index bc10adc94e4..79a6c84cb3c 100644
--- a/litellm/llms/bedrock/messages/invoke_transformations/anthropic_claude3_transformation.py
+++ b/litellm/llms/bedrock/messages/invoke_transformations/anthropic_claude3_transformation.py
@@ -676,14 +676,17 @@ class AmazonAnthropicClaudeMessagesConfig(
         clamped: Final = {"effort": effort}
         normalize_bedrock_opus_output_config_effort(model=model, output_config=clamped)
         optional_params["reasoning_effort"] = clamped["effort"]
-        explicit_effort: Final = AnthropicMessagesConfig._explicit_output_config_effort(
-            optional_params.get("output_config")
+        explicit_effort: Final = AnthropicMessagesConfig.explicit_output_config_effort(
+            cast(object, optional_params.get("output_config"))  # cast-ok: optional_params is an untyped dict
         )
         if explicit_effort is None:
             return
         clamped_explicit: Final = {"effort": explicit_effort}
         normalize_bedrock_opus_output_config_effort(model=model, output_config=clamped_explicit)
-        optional_params["output_config"] = {**optional_params["output_config"], **clamped_explicit}
+        optional_params["output_config"] = {  # rebind-ok: in-place fill is this method's contract
+            **optional_params["output_config"],
+            **clamped_explicit,
+        }
 
     def transform_anthropic_messages_request(
         self,