From b9028a16a38ec9087962e0097c1e79ce2c599104 Mon Sep 17 00:00:00 2001
From: Mason Daugherty <github@mdrxy.com>
Date: Wed, 6 Aug 2025 14:11:13 -0400
Subject: [PATCH] simplify response_metadata

---
 libs/core/langchain_core/messages/utils.py | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/libs/core/langchain_core/messages/utils.py b/libs/core/langchain_core/messages/utils.py
index 20207af7f79..68354f1427d 100644
--- a/libs/core/langchain_core/messages/utils.py
+++ b/libs/core/langchain_core/messages/utils.py
@@ -387,16 +387,12 @@ def convert_from_v1_message(message: MessageV1) -> BaseMessage:
     """
     content = cast("Union[str, list[str | dict]]", message.content)
     if isinstance(message, AIMessageV1):
-        response_metadata: dict[str, Any] = {}
-        if message.response_metadata:
-            # Copy all fields from the v1 ResponseMetadata to a plain dict
-            response_metadata.update(message.response_metadata)
         return AIMessage(
             content=content,
             id=message.id,
             name=message.name,
             tool_calls=message.tool_calls,
-            response_metadata=response_metadata,
+            response_metadata=cast("dict", message.response_metadata),
         )
     if isinstance(message, AIMessageChunkV1):
         response_metadata_chunk: dict[str, Any] = {}