解决Apex调用Stripe实现灵活付款条款时amounts_due参数错误问题

我正尝试在Salesforce中实现灵活付款条款（Flexible Payment Terms），通过Apex发起REST调用请求Stripe服务。参考官方文档实现，按照要求传递amounts_due参数创建带付款条款的发票，但收到如下错误：

{
  "error": {
    "code": "parameter_unknown",
    "doc_url": "https://stripe.com/docs/error-codes/parameter-unknown",
    "message": "Received unknown parameter: amounts_due",
    "param": "amounts_due",
    "request_log_url": "https://dashboard.stripe.com/test/logs/req_dsdMpC36mua7TP?t=1745322267",
    "type": "invalid_request_error"
  }
}

我的Apex代码如下：

public static void createInvoiceWithInstallments(String apiKey,String customerId) {
    HttpRequest req = new HttpRequest();
    req.setEndpoint('https://api.stripe.com/v1/invoices');
    req.setMethod('POST');
    req.setHeader('Authorization', 'Bearer ' + apiKey);
    req.setHeader('Content-Type', 'application/x-www-form-urlencoded');
        String body = 'customer=' + EncodingUtil.urlEncode(customerId, 'UTF-8') +
                  '&collection_method=send_invoice' +
                  '&auto_advance=true' +
                  '&amounts_due[][amount]=2000' +
                  '&amounts_due[][days_until_due]=30' +
                  '&amounts_due[][description]=' + EncodingUtil.urlEncode('Payment 1', 'UTF-8') +
                  '&amounts_due[][amount]=2000' +
                  '&amounts_due[][days_until_due]=60' +
                  '&amounts_due[][description]=' + EncodingUtil.urlEncode('Payment 2', 'UTF-8') +
                  '&amounts_due[][amount]=2000' +
                  '&amounts_due[][days_until_due]=90' +
                  '&amounts_due[][description]=' + EncodingUtil.urlEncode('Payment 3', 'UTF-8');                    
    req.setBody(body);        
    Http http = new Http();
    HttpResponse res = http.send(req);
    system.debug('req --> '+ req);
            if (res.getStatusCode() == 200 || res.getStatusCode() == 201) {
        System.debug('Stripe Invoice Created: ' + res.getBody());
    } else {
        System.debug('Stripe Invoice Creation Failed: ' + res.getBody());
        throw new StripeValidationException('Failed to create invoice. Code: ' + res.getStatusCode() + ' Body: ' + res.getBody());
    }
}   

我尝试过多种方式传递amounts_due参数，但均未解决问题，预期是通过Apex调用在Stripe中创建带付款计划的发票，实际收到未知参数错误，求解决方案。

解决方案 #

• 问题根源：Stripe的灵活付款条款并非直接通过amounts_due参数传入发票创建接口，正确的参数是payment_schedule，付款阶段明细需要包裹在payment_schedule[phases][]结构下。
• 修改后的Apex代码：

public static void createInvoiceWithInstallments(String apiKey,String customerId) {
    HttpRequest req = new HttpRequest();
    req.setEndpoint('https://api.stripe.com/v1/invoices');
    req.setMethod('POST');
    req.setHeader('Authorization', 'Bearer ' + apiKey);
    req.setHeader('Content-Type', 'application/x-www-form-urlencoded');
    
    // 使用正确的payment_schedule参数结构传递付款阶段
    String body = 'customer=' + EncodingUtil.urlEncode(customerId, 'UTF-8') +
              '&collection_method=send_invoice' +
              '&auto_advance=true' +
              // 第一阶段付款
              '&payment_schedule[phases][][amount]=2000' +
              '&payment_schedule[phases][][days_until_due]=30' +
              '&payment_schedule[phases][][description]=' + EncodingUtil.urlEncode('Payment 1', 'UTF-8') +
              // 第二阶段付款
              '&payment_schedule[phases][][amount]=2000' +
              '&payment_schedule[phases][][days_until_due]=60' +
              '&payment_schedule[phases][][description]=' + EncodingUtil.urlEncode('Payment 2', 'UTF-8') +
              // 第三阶段付款
              '&payment_schedule[phases][][amount]=2000' +
              '&payment_schedule[phases][][days_until_due]=90' +
              '&payment_schedule[phases][][description]=' + EncodingUtil.urlEncode('Payment 3', 'UTF-8');                    
    
    req.setBody(body);        
    Http http = new Http();
    HttpResponse res = http.send(req);
    system.debug('req --> '+ req);
    
    if (res.getStatusCode() == 200 || res.getStatusCode() == 201) {
        System.debug('Stripe Invoice Created: ' + res.getBody());
    } else {
        System.debug('Stripe Invoice Creation Failed: ' + res.getBody());
        throw new StripeValidationException('Failed to create invoice. Code: ' + res.getStatusCode() + ' Body: ' + res.getBody());
    }
}

• 额外注意事项：
  • 确保你的Stripe账号已开通Invoice Payment Plans功能，否则参数正确也会报错。
  • 验证所有付款阶段的金额总和与发票总金额匹配，避免金额不一致导致的验证错误。
  • 确保所有含特殊字符的字段都完成了URL编码。

内容的提问来源于stack exchange，提问作者Laxmi Kanta Kar