This is a simple script that passes a JSON configuration struct to an Arduino or ESP endpoint.
{
"command":"config",
"mqttserver":"your mqtt server",
"mqttuser":"user",
"mqttpass":"pass",
"ssid":"ssid",
"pass":"pass",
"devicename":"descriptive name",
"udp_broadcast":"false",
"A0":"disabled",
"A1":"disabled",
"A2":"disabled",
"A3":"disabled",
"A4":"disabled",
"A5":"disabled",
"A6":"disabled",
"A7":"disabled",
"A9":"disabled"
}