Populate variable set variables via REST for Service Catalog APISummaryThis article explains how to Populate variable set variables via REST call for Service Catalog APIInstructions 1. Create a catalog item, which contains :One single line text variable (slt),One Single-Row Variable Set, which contains one Single line text (Slt2) andOne Multi-Row Variable Set (mrvs), which contains one Single line text (Slt3) The format of JSON request object would be like :{"sys_id" : "039c516237b1300054b6a3549dbe5dfc","sysparm_quantity" : "1","variables" : {"slt" : "slt_value","slt2" : "slt2_value""mrvs" : "[{\"slt3\" : \"slt3_value\"}]"}} For Single-Row Variable Set, we don't need to mention the internal_name of Variable set. However, for'mvrs' we need to mention its name and the value should be an array of JSON objects. If the variable as a reference set as below, then you set the value as below when you use REST, where ee329ce2dbb033002878dc965e96196c is the sys_id of the reference field value. "slvset1Qref" : "ee329ce2dbb033002878dc965e96196c" ( For Reference Field you should use sys_id) .