Zabbix server uses a JSON- based communication protocol for receiving data from Zabbix sender with the help of trapper item.
For definition of header and data length please refer to protocol details section.
{
           "request":"sender data",
           "data":[
               {
                   "host":"<hostname>",
                   "key":"trap",
                   "value":"test value",
                   "clock":1516710794
               },
               {
                   "host":"<hostname>",
                   "key":"trap",
                   "value":"test value",
                   "clock":1516710795
               }
           ],
           "clock":1516712029,
           "ns":873386094
       }