diff --git a/src/share/system_variable/ob_system_variable_init.json b/src/share/system_variable/ob_system_variable_init.json
index ab6979c6c..f43a23243 100644
--- a/src/share/system_variable/ob_system_variable_init.json
+++ b/src/share/system_variable/ob_system_variable_init.json
@@ -10523,5 +10523,21 @@
     "info_cn": "",
     "background_cn": "",
     "ref_url": ""
+  },
+  "__ob_client_capability_flag": {
+    "id": 10643,
+    "name": "__ob_client_capability_flag",
+    "default_value": "0",
+    "base_value": "0",
+    "data_type": "uint",
+    "info": "Indicate features that observer supports, readonly after modified by first observer",
+    "flags": "READONLY | SESSION | INVISIBLE",
+    "min_val": "0",
+    "max_val": "18446744073709551615",
+    "publish_version": "",
+    "info_cn": "Negotiation mark between server and client",
+    "background_cn": "",
+    "ref_url": "",
+    "placeholder": true
   }
 }