Looks like the API is chequing the value of certain parameters, wich is a good thing, but I think this check is superfluous

curl --insecure -sS -H "Content-Type: application/json-rpc" -H "Authorization: Bearer 9fd35a709c030faca6f201ede2fe1b3f38d89106d4b9cc3ef809d0398bc94aee"  -d '{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "history.get",
  "params": {
    "itemids": [
      "48490"
    ],
    "sortorder": [
      "desc"
    ]
  }
}' http://192.168.200.64/api_jsonrpc.php
{"jsonrpc":"2.0","error":{"code":-32602,"message":"Invalid params.","data":"Invalid parameter \"/sortorder/1\": value must be one of \"ASC\", \"DESC\"."},"id":1}