[1.1 数据交互](%E6%95%B0%E6%8D%AE%E4%BA%A4%E4%BA%92.md) [1.2 签名方式](1.2%E7%AD%BE%E5%90%8D%E6%96%B9%E5%BC%8F.md) [1.3 商户授权](1.3%E5%95%86%E6%88%B7%E6%8E%88%E6%9D%83.md) [1.4 刷新token](1.4%E5%88%B7%E6%96%B0token.md) [1.5 常见问题](1.5%E5%B8%B8%E8%A7%81%E9%97%AE%E9%A2%98.md)