From b93f8296e8ca9d466cb78e992c5e53ed061f853b Mon Sep 17 00:00:00 2001
From: Ziyang Guo <121015044+RerankerGuo@users.noreply.github.com>
Date: Wed, 1 Jul 2026 22:42:50 +0800
Subject: [PATCH] fix: keep fast memories when fine transfer fails

---
 .../handlers/mem_read_handler.py              |  9 ++++-
 tests/mem_scheduler/test_mem_read_handler.py  | 38 +++++++++++++++++++
 2 files changed, 46 insertions(+), 1 deletion(-)
 create mode 100644 tests/mem_scheduler/test_mem_read_handler.py

diff --git a/src/memos/mem_scheduler/task_schedule_modules/handlers/mem_read_handler.py b/src/memos/mem_scheduler/task_schedule_modules/handlers/mem_read_handler.py
index 90ace633c..3e247414f 100644
--- a/src/memos/mem_scheduler/task_schedule_modules/handlers/mem_read_handler.py
+++ b/src/memos/mem_scheduler/task_schedule_modules/handlers/mem_read_handler.py
@@ -167,6 +167,7 @@ def _process_memories_with_reader(
 
             info = dict(info or {})
             is_upload_skill = info.pop("is_upload_skill", False)
+            transfer_succeeded = False
 
             try:
                 processed_memories = mem_reader.fine_transfer_simple_mem(
@@ -178,6 +179,7 @@ def _process_memories_with_reader(
                     user_context=user_context,
                     is_upload_skill=is_upload_skill,
                 )
+                transfer_succeeded = True
             except Exception as e:
                 logger.warning("%s: Fail to transfer mem: %s", e, memory_items)
                 processed_memories = []
@@ -402,7 +404,7 @@ def _process_memories_with_reader(
             if bindings_to_delete:
                 delete_ids.extend(list(bindings_to_delete))
             delete_ids = list(dict.fromkeys(delete_ids))
-            if delete_ids:
+            if delete_ids and transfer_succeeded:
                 try:
                     if getattr(mem_reader, "memory_version_switch", "off") != "on":
                         text_mem.delete(delete_ids, user_name=user_name)
@@ -434,6 +436,11 @@ def _process_memories_with_reader(
                         )
                 except Exception as e:
                     logger.warning("Failed to delete some mem_ids %s: %s", delete_ids, e)
+            elif delete_ids:
+                logger.info(
+                    "Skip deleting raw/working mem_ids after failed transfer: %s",
+                    delete_ids,
+                )
             else:
                 logger.info("No mem_ids to delete (nothing to cleanup)")
 
diff --git a/tests/mem_scheduler/test_mem_read_handler.py b/tests/mem_scheduler/test_mem_read_handler.py
new file mode 100644
index 000000000..5a3513f80
--- /dev/null
+++ b/tests/mem_scheduler/test_mem_read_handler.py
@@ -0,0 +1,38 @@
+from types import SimpleNamespace
+from unittest.mock import MagicMock
+
+from memos.mem_scheduler.task_schedule_modules.handlers.mem_read_handler import (
+    MemReadMessageHandler,
+)
+
+
+def test_mem_read_handler_keeps_fast_memories_when_transfer_fails():
+    mem_reader = MagicMock()
+    mem_reader.fine_transfer_simple_mem.side_effect = RuntimeError("extract failed")
+    mem_reader.memory_version_switch = "off"
+
+    raw_memory = SimpleNamespace(
+        memory="raw user message",
+        metadata=SimpleNamespace(background="", memory_type="LongTermMemory"),
+    )
+
+    text_mem = MagicMock()
+    text_mem.get.return_value = raw_memory
+    text_mem.memory_manager = SimpleNamespace(
+        remove_and_refresh_memory=MagicMock(),
+    )
+
+    scheduler_context = MagicMock()
+    scheduler_context.get_mem_reader.return_value = mem_reader
+
+    handler = MemReadMessageHandler(scheduler_context)
+    handler._process_memories_with_reader(
+        mem_ids=["fast-1"],
+        user_id="user-1",
+        mem_cube_id="cube-1",
+        text_mem=text_mem,
+        user_name="alice",
+    )
+
+    text_mem.delete.assert_not_called()
+    text_mem.soft_delete.assert_not_called()