From a19b74154aeadbaa6c26a0e17cfa22d022359cc5 Mon Sep 17 00:00:00 2001
From: Huaiwu Li <lhwzds@gmail.com>
Date: Sun, 14 Sep 2025 16:34:34 -0700
Subject: [PATCH] docs: Add missing merge parameter documentation in
 push_ui_message (#6145)

**Description:**
This PR adds missing documentation for the `merge` parameter in the
`push_ui_message` function. The parameter was present in the function
signature but lacked documentation in the docstring, which could confuse
API users.

  Changes made:
  - Added clear documentation for the `merge` parameter
  - Explains the behavior difference between `merge=True`
  (merges props) and `merge=False` (replaces props)
  - Includes default value information

  **Issue:**
  N/A - Documentation improvement

  **Dependencies:**
  None
---
 libs/langgraph/langgraph/graph/ui.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/libs/langgraph/langgraph/graph/ui.py b/libs/langgraph/langgraph/graph/ui.py
index f2fe5a1c2..5eb10e532 100644
--- a/libs/langgraph/langgraph/graph/ui.py
+++ b/libs/langgraph/langgraph/graph/ui.py
@@ -82,6 +82,8 @@ def push_ui_message(
         message: Optional message object to associate with the UI message.
         state_key: Key in the graph state where the UI messages are stored.
             Defaults to "ui".
+        merge: Whether to merge props with existing UI message (True) or replace
+            them (False). Defaults to False.
 
     Returns:
         The created UI message.