diff --git a/schema/type.graphql b/schema/type.graphql
index 4a88fd51..3ced0a03 100644
--- a/schema/type.graphql
+++ b/schema/type.graphql
@@ -135,6 +135,7 @@ type Topic {
   pic: String
   stat: TopicStat
   oid: String
+  is_main: Boolean
 }
 
 # output type