diff --git a/lightx2v/server/__main__.py b/lightx2v/server/__main__.py
index 06f2d2d4c..1c848abf6 100644
--- a/lightx2v/server/__main__.py
+++ b/lightx2v/server/__main__.py
@@ -13,6 +13,7 @@ def main():
     parser.add_argument("--host", type=str, default="0.0.0.0", help="Server host")
     parser.add_argument("--port", type=int, default=8000, help="Server port")
     parser.add_argument("--max_queue_size", type=int, default=10, help="Maximum active tasks (pending + processing)")
+    parser.add_argument("--history_limit", type=int, default=1000, help="Maximum completed tasks to keep in history")
 
     args, unknown = parser.parse_known_args()
 
diff --git a/lightx2v/server/config.py b/lightx2v/server/config.py
index c7bfccbf2..84e3af826 100644
--- a/lightx2v/server/config.py
+++ b/lightx2v/server/config.py
@@ -12,7 +12,7 @@ class ServerConfig:
     max_queue_size: int = 10
 
     task_timeout: int = 300
-    task_history_limit: int = 1000
+    history_limit: int = 1000
 
     http_timeout: int = 30
     http_max_retries: int = 3
@@ -41,6 +41,12 @@ def from_env(cls) -> "ServerConfig":
             except ValueError:
                 logger.warning(f"Invalid max queue size: {env_queue_size}")
 
+        if env_history_limit := os.environ.get("LIGHTX2V_HISTORY_LIMIT"):
+            try:
+                config.history_limit = int(env_history_limit)
+            except ValueError:
+                logger.warning(f"Invalid task history limit: {env_history_limit}")
+
         # MASTER_ADDR is now managed by torchrun, no need to set manually
 
         if env_cache_dir := os.environ.get("LIGHTX2V_CACHE_DIR"):
@@ -59,6 +65,10 @@ def validate(self) -> bool:
             logger.error("task_timeout must be positive")
             valid = False
 
+        if self.history_limit < 0:
+            logger.error("history_limit must be >= 0")
+            valid = False
+
         return valid
 
 
diff --git a/lightx2v/server/main.py b/lightx2v/server/main.py
index 853628830..9b7951e69 100644
--- a/lightx2v/server/main.py
+++ b/lightx2v/server/main.py
@@ -47,6 +47,11 @@ def _signal_handler(signum, frame):
         task_manager.set_max_queue_size(server_config.max_queue_size)
         logger.info(f"Task queue size set to {server_config.max_queue_size}")
 
+        if hasattr(args, "history_limit") and args.history_limit is not None:
+            server_config.history_limit = int(args.history_limit)
+        task_manager.set_history_limit(server_config.history_limit)
+        logger.info(f"Task history limit set to {server_config.history_limit}")
+
         if not server_config.validate():
             raise RuntimeError("Invalid server configuration")
 
diff --git a/lightx2v/server/task_manager.py b/lightx2v/server/task_manager.py
index 5c53ea096..5be41c03f 100644
--- a/lightx2v/server/task_manager.py
+++ b/lightx2v/server/task_manager.py
@@ -35,8 +35,9 @@ class TaskInfo:
 
 
 class TaskManager:
-    def __init__(self, max_queue_size: int = 100):
+    def __init__(self, max_queue_size: int = 100, history_limit: int = 1000):
         self.max_queue_size = max_queue_size
+        self.history_limit = history_limit
 
         self._tasks: OrderedDict[str, TaskInfo] = OrderedDict()
         self._lock = threading.RLock()
@@ -94,6 +95,7 @@ def complete_task(self, task_id: str, save_result_path: Optional[str] = None, re
             task.end_time = datetime.now()
             task.save_result_path = save_result_path
             task.result_png = result_png
+            task.message = None
 
             self.completed_tasks += 1
             self._emit_queue_metrics_unlocked()
@@ -231,15 +233,21 @@ def set_max_queue_size(self, max_queue_size: int):
             self.max_queue_size = max_queue_size
             self._emit_queue_metrics_unlocked()
 
-    def _cleanup_old_tasks(self, keep_count: int = 1000):
-        if len(self._tasks) <= keep_count:
+    def set_history_limit(self, history_limit: int):
+        if history_limit < 0:
+            raise ValueError("history_limit must be >= 0")
+        with self._lock:
+            self.history_limit = history_limit
+
+    def _cleanup_old_tasks(self):
+        if len(self._tasks) <= self.history_limit:
             return
 
         completed_tasks = [(task_id, task) for task_id, task in self._tasks.items() if task.status in [TaskStatus.COMPLETED, TaskStatus.FAILED, TaskStatus.CANCELLED]]
 
         completed_tasks.sort(key=lambda x: x[1].end_time or x[1].start_time)
 
-        remove_count = len(self._tasks) - keep_count
+        remove_count = len(self._tasks) - self.history_limit
         for task_id, _ in completed_tasks[:remove_count]:
             del self._tasks[task_id]
             logger.debug(f"Cleaned up old task: {task_id}")