关于steam 平台交易api

有谁使用steam api 发送过一个交易报价吗？

 private static string sentItems(string sessionID, string items, string[] Offer)
        {
            return Http.SteamWebRequest(cookiesContainer,
                 "tradeoffer/new/send",
                 "sessionid=" + sessionID +
                 "&partner=" + Offer[0] +
                 "&tradeoffermessage=&json_tradeoffer=%7B%22newversion%22%3Atrue%2C%22version%22%3A2%2C%22me%22%3A%7B%22assets%22%3A%5B" + items +
                 "%5D%2C%22currency%22%3A%5B%5D%2C%22ready%22%3Afalse%7D%2C%22them%22%3A%7B%22assets%22%3A%5B%5D%2C%22currency%22%3A%5B%5D%2C%22ready%22%3Afalse%7D%7D&trade_offer_create_params=%7B%22trade_offer_access_token%22%3A%22" + Offer[2] + "%22%7D",
                 "tradeoffer/new/?partner=" + Offer[1] + "&token=" + Offer[2]);
        }

这是别人用c#写的一个交易请求，但是我不明白里面参数代表的具体意思，这是完整
url:http://steamcommunity.com/tradeoffer/new/send/,有谁能提供帮助吗？非常感谢!

没有文档只能猜测。
tradeoffer交易请求
sessionID回话id
partner合作伙伴
currency货币
assets资产
trade_offer_create_params交易请求创建参数
...