fix(memory): paginate delete_all across vector store pages (#6636)

Co-authored-by: kartik-mem0 <kartik.labhshetwar@mem0.ai>

mem0/memory/main.py

@@ -133,6 +133,7 @@ _SENSITIVE_SUFFIXES = (
 
 # Entity parameters that must be passed via filters, not top-level kwargs
 ENTITY_PARAMS = frozenset({"user_id", "agent_id", "run_id"})
+DELETE_ALL_BATCH_SIZE = 1000
 
 # Tenant-scoping fields that update() must never let caller-supplied metadata overwrite (issues #4490, #6277).
 _IDENTITY_KEYS = ENTITY_PARAMS | {"actor_id"}
@@ -1885,14 +1886,28 @@ class Memory(MemoryBase):
 
         keys, encoded_ids = process_telemetry_filters(filters)
         capture_event("mem0.delete_all", self, {"keys": keys, "encoded_ids": encoded_ids, "sync_type": "sync"})
-        # delete all vector memories and reset the collections
+        # Keep listing after each batch is deleted. Most vector stores cap
-        memories = self.vector_store.list(filters=filters)[0]
+        # list() at 100 results by default, which silently truncates deletes.
-        for memory in memories:
+        deleted_count = 0
-            self._delete_memory(memory.id)
+        seen_batches = set()
+        while True:
+            memories = self.vector_store.list(
+                filters=filters, top_k=DELETE_ALL_BATCH_SIZE
+            )[0]
+            if not memories:
+                break
+            batch_ids = tuple(sorted(str(memory.id) for memory in memories))
+            if batch_ids in seen_batches:
+                logger.warning("Stopping delete_all after a repeated memory batch")
+                break
+            seen_batches.add(batch_ids)
+            for memory in memories:
+                self._delete_memory(memory.id)
+            deleted_count += len(memories)
 
-        logger.info(f"Deleted {len(memories)} memories")
+        logger.info(f"Deleted {deleted_count} memories")
 
-        decay_usage_notice = detect_decay_usage_from_delete_all(len(memories))
+        decay_usage_notice = detect_decay_usage_from_delete_all(deleted_count)
         if decay_usage_notice:
             display_decay_usage_notice(self, "sync", "delete_all", *decay_usage_notice)
         else:
@@ -3515,26 +3530,45 @@ class AsyncMemory(MemoryBase):
 
         keys, encoded_ids = process_telemetry_filters(filters)
         capture_event("mem0.delete_all", self, {"keys": keys, "encoded_ids": encoded_ids, "sync_type": "async"})
-        memories = await asyncio.to_thread(self.vector_store.list, filters=filters)
+        deleted_count = 0
-
+        errors = []
-        delete_tasks = []
+        seen_batches = set()
-        for memory in memories[0]:
+        while True:
-            delete_tasks.append(self._delete_memory(memory.id, skip_entity_cleanup=True))
+            memories = await asyncio.to_thread(
-
+                self.vector_store.list,
-        results = await asyncio.gather(*delete_tasks, return_exceptions=True)
+                filters=filters,
+                top_k=DELETE_ALL_BATCH_SIZE,
+            )
+            batch = memories[0] if memories else []
+            if not batch:
+                break
+            batch_ids = tuple(sorted(str(memory.id) for memory in batch))
+            if batch_ids in seen_batches:
+                logger.warning("Stopping delete_all after a repeated memory batch")
+                break
+            seen_batches.add(batch_ids)
+            delete_tasks = [
+                self._delete_memory(memory.id, skip_entity_cleanup=True)
+                for memory in batch
+            ]
+            results = await asyncio.gather(*delete_tasks, return_exceptions=True)
+            batch_errors = [
+                result for result in results if isinstance(result, BaseException)
+            ]
+            errors.extend(batch_errors)
+            deleted_count += len(results) - len(batch_errors)
 
         if self._entity_store is not None:
             await self._bulk_clear_entity_store(filters)
 
-        errors = [r for r in results if isinstance(r, BaseException)]
         if errors:
-            logger.warning("Failed to delete %d out of %d memories", len(errors), len(results))
+            logger.warning("Failed to delete %d memories", len(errors))
             for err in errors:
                 logger.warning("Delete error: %s", err)
 
-        logger.info(f"Deleted {len(results) - len(errors)} memories")
+        logger.info(f"Deleted {deleted_count} memories")
 
-        decay_usage_notice = detect_decay_usage_from_delete_all(len(memories[0]))
+        decay_usage_notice = detect_decay_usage_from_delete_all(deleted_count)
         if decay_usage_notice:
             await display_decay_usage_notice_async(self, "async", "delete_all", *decay_usage_notice)
         else:

tests/memory/test_decay_usage_notice.py

@@ -91,7 +91,7 @@ def test_sync_delete_failure_does_not_trigger_decay_usage_notice(monkeypatch):
 def test_sync_delete_all_decay_usage_runs_after_success(monkeypatch):
     memory = make_sync_memory()
     memories = [SimpleNamespace(id="memory-1"), SimpleNamespace(id="memory-2")]
-    memory.vector_store.list.return_value = (memories, None)
+    memory.vector_store.list.side_effect = [(memories, None), ([], None)]
     decay_notice = MagicMock()
     first_run_notice = MagicMock()
     detect_decay = MagicMock(return_value=("delete_all", "bulk_delete", None, 2))
@@ -117,6 +117,21 @@ def test_sync_delete_all_decay_usage_runs_after_success(monkeypatch):
     first_run_notice.assert_not_called()
 
 
+def test_sync_delete_all_stops_when_vector_store_repeats_batch(monkeypatch):
+    memory = make_sync_memory()
+    memories = [SimpleNamespace(id="memory-1"), SimpleNamespace(id="memory-2")]
+    memory.vector_store.list.side_effect = [(memories, None), (memories, None)]
+    monkeypatch.setattr(memory_main, "capture_event", MagicMock())
+    monkeypatch.setattr(memory_main, "detect_decay_usage_from_delete_all", MagicMock(return_value=None))
+    monkeypatch.setattr(memory_main, "display_first_run_notice", MagicMock())
+
+    result = Memory.delete_all(memory, user_id="u1")
+
+    assert result == {"message": "Memories deleted successfully!"}
+    assert memory.vector_store.list.call_count == 2
+    assert memory._delete_memory.call_count == 2
+
+
 def test_sync_delete_all_zero_deletes_uses_first_run_notice(monkeypatch):
     memory = make_sync_memory()
     memory.vector_store.list.return_value = ([], None)
@@ -189,7 +204,7 @@ async def test_async_delete_failure_does_not_trigger_decay_usage_notice(monkeypa
 async def test_async_delete_all_decay_usage_runs_after_success(monkeypatch):
     memory = make_async_memory()
     memories = [SimpleNamespace(id="memory-1"), SimpleNamespace(id="memory-2")]
-    memory.vector_store.list.return_value = (memories, None)
+    memory.vector_store.list.side_effect = [(memories, None), ([], None)]
     decay_notice = AsyncMock()
     first_run_notice = AsyncMock()
     detect_decay = MagicMock(return_value=("delete_all", "bulk_delete", None, 2))
@@ -213,3 +228,23 @@ async def test_async_delete_all_decay_usage_runs_after_success(monkeypatch):
         2,
     )
     first_run_notice.assert_not_awaited()
+
+
+@pytest.mark.asyncio
+async def test_async_delete_all_stops_when_vector_store_repeats_batch(monkeypatch):
+    memory = make_async_memory()
+    memories = [SimpleNamespace(id="memory-1"), SimpleNamespace(id="memory-2")]
+    memory.vector_store.list.side_effect = [
+        (memories, None),
+        (memories, None),
+        RuntimeError("delete_all should have stopped before a third list() call"),
+    ]
+    monkeypatch.setattr(memory_main, "capture_event", MagicMock())
+    monkeypatch.setattr(memory_main, "detect_decay_usage_from_delete_all", MagicMock(return_value=None))
+    monkeypatch.setattr(memory_main, "display_first_run_notice_async", AsyncMock())
+
+    result = await AsyncMemory.delete_all(memory, user_id="u1")
+
+    assert result == {"message": "Memories deleted successfully!"}
+    assert memory.vector_store.list.call_count == 2
+    assert memory._delete_memory.await_count == 2

tests/test_main.py

@@ -280,19 +280,36 @@ def test_delete(memory_instance):
 
 def test_delete_all(memory_instance):
     mock_memories = [Mock(id="1"), Mock(id="2")]
-    memory_instance.vector_store.list = Mock(return_value=(mock_memories, None))
+    memory_instance.vector_store.list = Mock(side_effect=[(mock_memories, None), ([], None)])
     memory_instance.vector_store.reset = Mock()
     memory_instance._delete_memory = Mock()
 
     result = memory_instance.delete_all(user_id="test_user")
 
     assert memory_instance._delete_memory.call_count == 2
+    memory_instance.vector_store.list.assert_called_with(
+        filters={"user_id": "test_user"}, top_k=1000
+    )
     # Ensure the collection is NOT dropped — only matched memories should be removed
     memory_instance.vector_store.reset.assert_not_called()
 
     assert result["message"] == "Memories deleted successfully!"
 
 
+def test_delete_all_paginates_beyond_vector_store_page_size(memory_instance):
+    first_batch = [Mock(id=str(index)) for index in range(1000)]
+    second_batch = [Mock(id="1000")]
+    memory_instance.vector_store.list = Mock(
+        side_effect=[(first_batch, None), (second_batch, None), ([], None)]
+    )
+    memory_instance._delete_memory = Mock()
+
+    memory_instance.delete_all(user_id="test_user")
+
+    assert memory_instance._delete_memory.call_count == 1001
+    assert memory_instance.vector_store.list.call_count == 3
+
+
 def test_get_all(memory_instance):
     mock_memories = [Mock(id="1", payload={"data": "Memory 1", "user_id": "test_user"})]
     memory_instance.vector_store.list = Mock(return_value=(mock_memories, None))
@@ -431,7 +448,9 @@ class TestEntityIdValidation:
 
         memory_instance.delete_all(user_id="  alice  ")
 
-        memory_instance.vector_store.list.assert_called_once_with(filters={"user_id": "alice"})
+        memory_instance.vector_store.list.assert_called_once_with(
+            filters={"user_id": "alice"}, top_k=1000
+        )
 
     def test_validate_coerces_non_string_entity_id(self):
         """Integer (and other non-string) ids are coerced to str, not crashed on."""
@@ -444,7 +463,9 @@ class TestEntityIdValidation:
 
         memory_instance.delete_all(user_id=42)
 
-        memory_instance.vector_store.list.assert_called_once_with(filters={"user_id": "42"})
+        memory_instance.vector_store.list.assert_called_once_with(
+            filters={"user_id": "42"}, top_k=1000
+        )
 
     def test_get_all_coerces_integer_user_id(self, memory_instance):
         """get_all should accept an integer user_id in filters and scope by its str form."""

tests/test_memory.py

@@ -983,7 +983,7 @@ async def test_async_delete_all_continues_on_partial_failure(mock_sqlite, mock_l
     mem3.id = "mem-3"
     mem3.payload = {"data": "three", "created_at": "2024-01-01T00:00:00+00:00", "actor_id": None, "role": None}
 
-    mock_vector_store.list.return_value = ([mem1, mem2, mem3],)
+    mock_vector_store.list.side_effect = [([mem1, mem2, mem3],), ([],)]
 
     def _get_side_effect(vector_id):
         if vector_id == "mem-2":
@@ -999,6 +999,10 @@ async def test_async_delete_all_continues_on_partial_failure(mock_sqlite, mock_l
 
     assert result == {"message": "Memories deleted successfully!"}
     assert mock_vector_store.delete.call_count == 2
+    assert mock_vector_store.list.call_args_list[0].kwargs == {
+        "filters": {"user_id": "test-user"},
+        "top_k": 1000,
+    }
 
 
 @patch('mem0.utils.factory.EmbedderFactory.create')
@@ -1473,7 +1477,7 @@ class TestAsyncDeleteAllEntityRace:
         mem_b = MagicMock()
         mem_b.id = "mem-b"
         mem_b.payload = {"data": "Alice works at Acme", "user_id": "alice"}
-        mock_vector_store.list.return_value = ([mem_a, mem_b],)
+        mock_vector_store.list.side_effect = [([mem_a, mem_b],), ([],)]
         mock_vector_store.get.side_effect = lambda vector_id: {"mem-a": mem_a, "mem-b": mem_b}[vector_id]
         mock_vector_factory.return_value = mock_vector_store