From dc139746f14ecb4bc8ce0ee727c6b5daf9ac04d3 Mon Sep 17 00:00:00 2001
From: Nick Hollon <nick.hollon@langchain.dev>
Date: Tue, 26 May 2026 12:07:39 -0400
Subject: [PATCH] fix(langchain): collapse `_write_todos` `ToolMessage` to one
 line

`ruff format` wants the now-shorter message text on a single line.
The previous multi-line layout fit the longer "Updated todo list to
{todos}" payload; "Todo list updated." is short enough to inline.
---
 libs/langchain_v1/langchain/agents/middleware/todo.py | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/libs/langchain_v1/langchain/agents/middleware/todo.py b/libs/langchain_v1/langchain/agents/middleware/todo.py
index 06563f6b9f3..15781d85cfd 100644
--- a/libs/langchain_v1/langchain/agents/middleware/todo.py
+++ b/libs/langchain_v1/langchain/agents/middleware/todo.py
@@ -149,9 +149,7 @@ def _write_todos(
     return Command(
         update={
             "todos": todos,
-            "messages": [
-                ToolMessage("Todo list updated.", tool_call_id=runtime.tool_call_id)
-            ],
+            "messages": [ToolMessage("Todo list updated.", tool_call_id=runtime.tool_call_id)],
         }
     )