diff --git a/pipeline_service/audit.py b/pipeline_service/audit.py
index cde161d..344cbe7 100644
--- a/pipeline_service/audit.py
+++ b/pipeline_service/audit.py
@@ -10,6 +10,7 @@
 """
 
 import logging
+from datetime import datetime
 from sqlor.dbpools import DBPools
 from appPublic.uniqueID import getID
 
@@ -54,6 +55,8 @@ async def record_audit(tenant_id, entity, entity_id, action,
         'who': who,
         'agent_id': agent_id,
         'detail': detail,
+        # 微秒精度，保证 append-only 轨迹可精确排序（秒级同秒内会乱序）
+        'created_at': datetime.now().strftime('%Y-%m-%d %H:%M:%S.%f'),
     }
     if sor is not None:
         await sor.C('audit_log', data)