craveytrain

var callback = context.HttpContext.Request.QueryString.AllKeys.FirstOrDefault(k => k == "callback");
var data = "{ "key": "value" }"; // JSON payload

if(string.IsNullOrEmpty(callback))
{
    response.ContentType = "application/json";
    response.AddHeader("Access-Control-Allow-Origin", "*";
    response.Write(data);
}
else