From d1975b740b019ba1364eba7fdcf478ec99b19ca7 Mon Sep 17 00:00:00 2001
From: Classic298 <27028174+Classic298@users.noreply.github.com>
Date: Sun, 8 Mar 2026 02:19:44 +0100
Subject: [PATCH] fix: add deterministic ordering to chat_ids pagination query
 to prevent duplicates (#22383)

---
 backend/open_webui/models/chat_messages.py | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/backend/open_webui/models/chat_messages.py b/backend/open_webui/models/chat_messages.py
index e6e932be12..4cd868e4d4 100644
--- a/backend/open_webui/models/chat_messages.py
+++ b/backend/open_webui/models/chat_messages.py
@@ -292,9 +292,13 @@ class ChatMessageTable:
                 query = query.filter(ChatMessage.created_at <= end_date)
 
             # Group by chat_id and order by most recent message in each chat
+            # Secondary sort on chat_id ensures deterministic pagination
+            # (prevents duplicates across pages when timestamps tie)
             chat_ids = (
                 query.group_by(ChatMessage.chat_id)
-                .order_by(func.max(ChatMessage.created_at).desc())
+                .order_by(
+                    func.max(ChatMessage.created_at).desc(), ChatMessage.chat_id
+                )
                 .offset(skip)
                 .limit(limit)
                 .all()