[API] Cannot create discovery action

[sire]

I'm trying to use Zabbix 2.0 rc2. Cannot create discovery action that attaches a template to a discovered host.

My API JSON request:

{
   "params" : {
      "recovery_msg" : "0",
      "status" : "0",
      "r_shortdata" : "",
      "name" : "Автообнаружение",
      "operations" : [
         {
            "esc_step_from" : "1",
            "esc_period" : "0",
            "optemplate" : [
               "10016"
            ],
            "operationtype" : "6",
            "evaltype" : "0",
            "esc_step_to" : "1",
            "opconditions" : []
         }
      ],
      "esc_period" : "0",
      "def_shortdata" : "",
      "evaltype" : "0",
      "r_longdata" : "",
      "eventsource" : "1",
      "actionid" : "5",
      "def_longdata" : "",
      "conditions" : [
         {
            "operator" : "0",
            "value" : "4",
            "conditiontype" : "18"
         }
      ]
   },
   "auth" : "0e907e5d00862cb87912c63d294bca05",
   "jsonrpc" : "2.0",
   "method" : "action.update",
   "id" : 178
} 

I get the following error:

In create_or_update_discovery_action: Error: {"data":"JSON-rpc error generation failed. No such error \"\".","message":"System error.","code":-32400} 

What's wrong in my request?

[sire]

However the similar request for adding a host to a group works.

[sire]

My problem was that optemplates should be given as

"optemplate" : [
"templateid" : "10016"
]