使用Google Apps Script调用EasyPost API创建运单遇必填参数缺失错误

在Google Apps Script中调用EasyPost API创建运单，认证已成功，但收到422错误，提示shipment字段不能为空，错误信息如下：

Exception: Request failed for https://api.easypost.com returned code 422. Truncated server response: {"error":{"code":"PARAMETER.REQUIRED","message":"Missing required parameter.","errors":[{"field":"shipment","message":"cannot be blank"}]}}

附上相关代码：

function myFunction() {
  const api_key = 'TEST_API_KEY';
  const url = 'https://api.easypost.com/v2/shipments';

  const data = {
    "shipment": {
      "to_address": {
        "name": "Dr. Steve Brule",
        "street1": "179 N Harbor Dr",
        "city": "Redondo Beach",
        "state": "CA",
        "zip": "90277",
        "country": "US",
        "phone": "8573875756",
        "email": "dr_steve_brule@gmail.com"
      },
      "from_address": {
        "name": "EasyPost",
        "street1": "417 Montgomery Street",
        "street2": "5th Floor",
        "city": "San Francisco",
        "state": "CA",
        "zip": "94104",
        "country": "US",
        "phone": "4153334445",
        "email": "support@easypost.com"
      },
      "parcel": {
        "length": "20.2",
        "width": "10.9",
        "height": "5",
        "weight": "65.9"
      },
    }
  };

  const options = {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
      'Authorization': 'Basic ' + Utilities.base64Encode(api_key)
    },
    body: JSON.stringify(data)
  };

  const results = UrlFetchApp.fetch(url, options);
  console.log(results);
};

解决方案 #

出现这个错误的核心原因有两个：

1. Basic认证格式错误 #

EasyPost的API要求Basic认证格式为API Key + 冒号（密码留空）后进行Base64编码。原代码中仅对API Key进行编码，缺少冒号，导致服务器无法正确解析认证信息，进而无法识别请求体中的shipment参数。

2. JSON对象存在多余逗号 #

data.shipment.parcel对象末尾的多余逗号虽然不会导致JS报错，但可能在序列化时引发潜在问题，建议移除。

修改后的代码如下：

function myFunction() {
  const api_key = 'TEST_API_KEY';
  const url = 'https://api.easypost.com/v2/shipments';

  const data = {
    "shipment": {
      "to_address": {
        "name": "Dr. Steve Brule",
        "street1": "179 N Harbor Dr",
        "city": "Redondo Beach",
        "state": "CA",
        "zip": "90277",
        "country": "US",
        "phone": "8573875756",
        "email": "dr_steve_brule@gmail.com"
      },
      "from_address": {
        "name": "EasyPost",
        "street1": "417 Montgomery Street",
        "street2": "5th Floor",
        "city": "San Francisco",
        "state": "CA",
        "zip": "94104",
        "country": "US",
        "phone": "4153334445",
        "email": "support@easypost.com"
      },
      "parcel": {
        "length": "20.2",
        "width": "10.9",
        "height": "5",
        "weight": "65.9"
      }
    }
  };

  const options = {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
      'Authorization': 'Basic ' + Utilities.base64Encode(api_key + ':')
    },
    body: JSON.stringify(data)
  };

  const results = UrlFetchApp.fetch(url, options);
  console.log(results);
};

内容的提问来源于stack exchange，提问作者Sam WB