diff --git a/doc/_common.py b/doc/_common.py
new file mode 100644
index 00000000..f3338ca4
--- /dev/null
+++ b/doc/_common.py
@@ -0,0 +1,17 @@
+# -*- coding: utf-8 -*-
+
+class ReqHead(object):
+
+    def __init__(self):
+        self.params = [
+            ['account_id', '', '账号id'],
+            ['session_id', '', '会话id'],
+        ]
+
+class RspHead(object):
+
+    def __init__(self):
+        self.fields = [
+            ['errcode', 0, '错误码'],
+            ['errmsg', '', '错误描述'],
+        ]