diff --git a/src/blackboard/db.py b/src/blackboard/db.py
index aa4a6dd..57dd729 100644
--- a/src/blackboard/db.py
+++ b/src/blackboard/db.py
@@ -143,6 +143,11 @@ def _migrate_v28(conn: sqlite3.Connection) -> None:
     _safe_add_column(conn, "outputs", "mime_type", "TEXT")
 
 
+def _migrate_v29(conn: sqlite3.Connection) -> None:
+    """v2.9 迁移：events 表加 payload 列（结构化 JSON 详情）"""
+    _safe_add_column(conn, "events", "payload", "TEXT")
+
+
 def _safe_add_column(conn: sqlite3.Connection, table: str,
                      column: str, col_type: str) -> None:
     """安全添加列（已存在则跳过）"""