To add metadata to a group, send the metadata object inside the group object while creating a group. The same metadata object will be received in group list API with group object. The metadata object is a map with string keys and values.

Sample Group Object JSON with Metadata:

 "clientGroupId":"Client Group Id",
 "groupName" : "Group Name",
 "groupMemberList" : ["UserName1", "UserName2", "UserName3"],
 "imageUrl": "Group image Url",
 "metadata" : {
   "key1" : "value1",
   "key2" : "value2"