diff --git a/src/daemon/spawner.py b/src/daemon/spawner.py
index 89f9d3d..824b75c 100644
--- a/src/daemon/spawner.py
+++ b/src/daemon/spawner.py
@@ -188,9 +188,13 @@ class AgentSpawner:
         message: str,
         new_session: bool = False,
         task_id: Optional[str] = None,
+        on_complete: Optional[Any] = None,
     ) -> str:
         """Spawn Full Agent（异步非阻塞）
 
+        Args:
+            on_complete: async callback(agent_id, outcome) — Agent 完成后调用
+
         Returns:
             session_id
         """
@@ -221,7 +225,8 @@ class AgentSpawner:
 
             # Schedule timeout + cleanup
             asyncio.create_task(
-                self._monitor_process(session_id, proc, agent_id, task_id)
+                self._monitor_process(session_id, proc, agent_id, task_id,
+                                      on_complete=on_complete)
             )
 
             return session_id
@@ -259,6 +264,7 @@ class AgentSpawner:
         proc: asyncio.subprocess.Process,
         agent_id: str,
         task_id: Optional[str],
+        on_complete: Optional[Any] = None,
     ) -> None:
         """监控子进程，超时 kill，完成后记录"""
         try:
@@ -283,6 +289,14 @@ class AgentSpawner:
         logger.info("Agent %s finished (session=%s, outcome=%s, exit=%d)",
                      agent_id, session_id, outcome, exit_code)
 
+        # 完成回调（释放 counter 等）
+        if on_complete:
+            try:
+                await on_complete(agent_id, outcome)
+            except Exception:
+                logger.warning("on_complete callback failed for %s",
+                               agent_id, exc_info=True)
+
     def _register_session(
         self,
         session_id: str,