diff --git a/backend/packages/harness/deerflow/runtime/runs/manager.py b/backend/packages/harness/deerflow/runtime/runs/manager.py
index cce8e3bf5..ae8d89289 100644
--- a/backend/packages/harness/deerflow/runtime/runs/manager.py
+++ b/backend/packages/harness/deerflow/runtime/runs/manager.py
@@ -144,6 +144,9 @@ class RunManager:
             self._runs[run_id] = record
             try:
                 await self._persist_new_run_to_store(record)
+            except asyncio.CancelledError:
+                self._runs.pop(run_id, None)
+                raise
             except Exception:
                 self._runs.pop(run_id, None)
                 logger.warning("Failed to persist run %s; rolled back in-memory record", run_id, exc_info=True)
@@ -348,6 +351,9 @@ class RunManager:
             self._runs[run_id] = record
             try:
                 await self._persist_new_run_to_store(record)
+            except asyncio.CancelledError:
+                self._runs.pop(run_id, None)
+                raise
             except Exception:
                 self._runs.pop(run_id, None)
                 logger.warning("Failed to persist run %s; rolled back in-memory record", run_id, exc_info=True)
diff --git a/backend/tests/test_run_manager.py b/backend/tests/test_run_manager.py
index 8dbd277b6..4b88c8501 100644
--- a/backend/tests/test_run_manager.py
+++ b/backend/tests/test_run_manager.py
@@ -2,6 +2,7 @@
 
 import asyncio
 import re
+from contextlib import suppress
 
 import pytest
 
@@ -248,6 +249,24 @@ async def test_create_rolls_back_in_memory_record_on_store_failure():
     assert await manager.list_by_thread("thread-1") == []
 
 
+@pytest.mark.anyio
+async def test_create_rolls_back_in_memory_record_on_store_cancellation():
+    """create() must also roll back when cancelled during the initial store write."""
+    store = MemoryRunStore()
+
+    async def cancelled_put(run_id, **kwargs):
+        raise asyncio.CancelledError
+
+    store.put = cancelled_put
+    manager = RunManager(store=store)
+
+    with pytest.raises(asyncio.CancelledError):
+        await manager.create("thread-1")
+
+    assert manager._runs == {}
+    assert await manager.list_by_thread("thread-1") == []
+
+
 @pytest.mark.anyio
 async def test_create_does_not_expose_run_until_store_persist_completes():
     """Concurrent readers must wait until the new run has been persisted."""
@@ -264,6 +283,7 @@ async def test_create_does_not_expose_run_until_store_persist_completes():
 
     store.put = blocking_put
     create_task = asyncio.create_task(manager.create("thread-1"))
+    list_task = None
 
     try:
         await put_started.wait()
@@ -278,8 +298,13 @@ async def test_create_does_not_expose_run_until_store_persist_completes():
         assert [run.run_id for run in runs] == [record.run_id]
     finally:
         allow_put.set()
-        if not create_task.done():
-            create_task.cancel()
+        for task in (list_task, create_task):
+            if task is None:
+                continue
+            if not task.done():
+                task.cancel()
+            with suppress(asyncio.CancelledError):
+                await task
 
 
 @pytest.mark.anyio
@@ -391,6 +416,30 @@ async def test_create_or_reject_does_not_interrupt_old_run_when_new_run_store_wr
     assert stored_old["status"] == "running"
 
 
+@pytest.mark.anyio
+async def test_create_or_reject_does_not_interrupt_old_run_when_new_run_store_write_is_cancelled():
+    """Cancellation during new-run persist must not cancel the existing run."""
+    store = MemoryRunStore()
+    manager = RunManager(store=store)
+    old = await manager.create("thread-1")
+    await manager.set_status(old.run_id, RunStatus.running)
+
+    async def cancelled_put(run_id, **kwargs):
+        raise asyncio.CancelledError
+
+    store.put = cancelled_put
+
+    with pytest.raises(asyncio.CancelledError):
+        await manager.create_or_reject("thread-1", multitask_strategy="interrupt")
+
+    stored_old = await store.get(old.run_id)
+    assert list(manager._runs) == [old.run_id]
+    assert old.status == RunStatus.running
+    assert old.abort_event.is_set() is False
+    assert stored_old is not None
+    assert stored_old["status"] == "running"
+
+
 @pytest.mark.anyio
 async def test_create_or_reject_rollback_persists_interrupted_status_to_store():
     """rollback strategy should persist interrupted status for old runs."""