diff --git a/nanobot/agent/loop.py b/nanobot/agent/loop.py
index 96b5b30c6..0031c90c5 100644
--- a/nanobot/agent/loop.py
+++ b/nanobot/agent/loop.py
@@ -129,6 +129,7 @@ class AgentLoop:
     """
 
     _RUNTIME_CHECKPOINT_KEY = "runtime_checkpoint"
+    _PENDING_USER_TURN_KEY = "pending_user_turn"
 
     def __init__(
         self,
@@ -618,6 +619,8 @@ class AgentLoop:
             session = self.sessions.get_or_create(key)
             if self._restore_runtime_checkpoint(session):
                 self.sessions.save(session)
+            if self._restore_pending_user_turn(session):
+                self.sessions.save(session)
 
             session, pending = self.auto_compact.prepare_session(session, key)
 
@@ -653,6 +656,8 @@ class AgentLoop:
         session = self.sessions.get_or_create(key)
         if self._restore_runtime_checkpoint(session):
             self.sessions.save(session)
+        if self._restore_pending_user_turn(session):
+            self.sessions.save(session)
 
         session, pending = self.auto_compact.prepare_session(session, key)
 
@@ -702,6 +707,7 @@ class AgentLoop:
         user_persisted_early = False
         if isinstance(msg.content, str) and msg.content.strip():
             session.add_message("user", msg.content)
+            self._mark_pending_user_turn(session)
             self.sessions.save(session)
             user_persisted_early = True
 
@@ -723,6 +729,7 @@ class AgentLoop:
         # Skip the already-persisted user message when saving the turn
         save_skip = 1 + len(history) + (1 if user_persisted_early else 0)
         self._save_turn(session, all_msgs, save_skip)
+        self._clear_pending_user_turn(session)
         self._clear_runtime_checkpoint(session)
         self.sessions.save(session)
         self._schedule_background(self.consolidator.maybe_consolidate_by_tokens(session))
@@ -840,6 +847,12 @@ class AgentLoop:
         session.metadata[self._RUNTIME_CHECKPOINT_KEY] = payload
         self.sessions.save(session)
 
+    def _mark_pending_user_turn(self, session: Session) -> None:
+        session.metadata[self._PENDING_USER_TURN_KEY] = True
+
+    def _clear_pending_user_turn(self, session: Session) -> None:
+        session.metadata.pop(self._PENDING_USER_TURN_KEY, None)
+
     def _clear_runtime_checkpoint(self, session: Session) -> None:
         if self._RUNTIME_CHECKPOINT_KEY in session.metadata:
             session.metadata.pop(self._RUNTIME_CHECKPOINT_KEY, None)
@@ -906,9 +919,30 @@ class AgentLoop:
                 break
         session.messages.extend(restored_messages[overlap:])
 
+        self._clear_pending_user_turn(session)
         self._clear_runtime_checkpoint(session)
         return True
 
+    def _restore_pending_user_turn(self, session: Session) -> bool:
+        """Close a turn that only persisted the user message before crashing."""
+        from datetime import datetime
+
+        if not session.metadata.get(self._PENDING_USER_TURN_KEY):
+            return False
+
+        if session.messages and session.messages[-1].get("role") == "user":
+            session.messages.append(
+                {
+                    "role": "assistant",
+                    "content": "Error: Task interrupted before a response was generated.",
+                    "timestamp": datetime.now().isoformat(),
+                }
+            )
+            session.updated_at = datetime.now()
+
+        self._clear_pending_user_turn(session)
+        return True
+
     async def process_direct(
         self,
         content: str,
diff --git a/tests/agent/test_loop_save_turn.py b/tests/agent/test_loop_save_turn.py
index c499282ab..c965ccd8c 100644
--- a/tests/agent/test_loop_save_turn.py
+++ b/tests/agent/test_loop_save_turn.py
@@ -229,6 +229,7 @@ async def test_process_message_persists_user_message_before_turn_completes(tmp_p
     persisted = loop.sessions.get_or_create("feishu:c1")
     assert [m["role"] for m in persisted.messages] == ["user"]
     assert persisted.messages[0]["content"] == "persist me"
+    assert persisted.metadata.get(AgentLoop._PENDING_USER_TURN_KEY) is True
     assert persisted.updated_at >= persisted.created_at
 
 
@@ -262,3 +263,48 @@ async def test_process_message_does_not_duplicate_early_persisted_user_message(t
         {"role": "user", "content": "hello"},
         {"role": "assistant", "content": "done"},
     ]
+    assert AgentLoop._PENDING_USER_TURN_KEY not in session.metadata
+
+
+@pytest.mark.asyncio
+async def test_next_turn_after_crash_closes_pending_user_turn_before_new_input(tmp_path: Path) -> None:
+    loop = _make_full_loop(tmp_path)
+    loop.consolidator.maybe_consolidate_by_tokens = AsyncMock(return_value=False)  # type: ignore[method-assign]
+    loop.provider.chat_with_retry = AsyncMock(return_value=MagicMock())  # unused because _run_agent_loop is stubbed
+
+    session = loop.sessions.get_or_create("feishu:c3")
+    session.add_message("user", "old question")
+    session.metadata[AgentLoop._PENDING_USER_TURN_KEY] = True
+    loop.sessions.save(session)
+
+    loop._run_agent_loop = AsyncMock(return_value=(
+        "new answer",
+        None,
+        [
+            {"role": "system", "content": "system"},
+            {"role": "user", "content": "old question"},
+            {"role": "assistant", "content": "Error: Task interrupted before a response was generated."},
+            {"role": "user", "content": "new question"},
+            {"role": "assistant", "content": "new answer"},
+        ],
+        "stop",
+        False,
+    ))  # type: ignore[method-assign]
+
+    result = await loop._process_message(
+        InboundMessage(channel="feishu", sender_id="u1", chat_id="c3", content="new question")
+    )
+
+    assert result is not None
+    assert result.content == "new answer"
+    session = loop.sessions.get_or_create("feishu:c3")
+    assert [
+        {k: v for k, v in m.items() if k in {"role", "content"}}
+        for m in session.messages
+    ] == [
+        {"role": "user", "content": "old question"},
+        {"role": "assistant", "content": "Error: Task interrupted before a response was generated."},
+        {"role": "user", "content": "new question"},
+        {"role": "assistant", "content": "new answer"},
+    ]
+    assert AgentLoop._PENDING_USER_TURN_KEY not in session.metadata