Flutter集成Agora时，云函数生成的RTC Token始终提示无效

我用以下云函数代码为Flutter应用生成Agora视频通话的RTC Token，Agora控制台生成的临时Token能正常使用，但云函数生成的Token却报错，已经确认AppID和AppCertificate是正确的。

import pkg from 'agora-access-token';
const { RtcTokenBuilder, RtcRole } = pkg;

export default async ({ req, res, log, error }) => {
   if (req.method === 'POST') {
   let requestBody;
if (typeof req.body === 'string') {
  requestBody = JSON.parse(req.body);
} else {  
  requestBody = req.body; 
}
const { channelName, uid } = requestBody;
const appId = process.env.APP_ID;
const appCertificate = process.env.APP_CERTIFICATE;
const role = RtcRole.PUBLISHER;
log('Request body:', requestBody);
log('Channel Name:', channelName);
log('UID:', uid);
log('App ID:', appId);
log('App Certificate:', appCertificate);

const expirationTimeInSeconds = 3600;
const currentTimestamp = Math.floor(Date.now() / 1000);
const privilegeExpiredTs = Math.floor(currentTimestamp + expirationTimeInSeconds);

const token = RtcTokenBuilder.buildTokenWithUid(
  appId, 
  appCertificate, 
  channelName, 
  uid,
  role, 
  privilegeExpiredTs
);

log('Generated Token:', token);

return res.json({ token, uid: uid.toString() });
} else {
res.status(405).json({ message: 'Method not allowed' });
}
}

核心排查点与修复 #

1. UID类型不匹配 #

RtcTokenBuilder.buildTokenWithUid要求uid是整数类型，如果前端传入的uid是字符串格式（比如"12345"），直接传入会导致Token生成逻辑错误。

修复：
提取uid后转为整数，并处理非法值：

const { channelName, uid: rawUid } = requestBody;
const uid = parseInt(rawUid, 10);
const finalUid = isNaN(uid) ? 0 : uid; // 0表示Agora随机分配UID

2. 频道名大小写/格式问题 #

Agora频道名大小写敏感，且仅允许a-z、A-Z、0-9、-_!#$%&()+-<>.?@[]^_{}~这些字符。如果请求传入的频道名包含非法字符，或与前端连接时的频道名大小写不一致，会导致Token验证失败。

修复：
生成Token前标准化频道名：

const normalizedChannel = channelName.trim().toLowerCase();

3. 请求体解析异常 #

如果请求体格式不符合JSON规范，JSON.parse会抛出错误，导致后续逻辑中断。

修复：
添加解析异常捕获：

let requestBody;
try {
  requestBody = typeof req.body === 'string' ? JSON.parse(req.body) : req.body;
} catch (err) {
  error('请求体解析失败:', err);
  return res.status(400).json({ message: '无效的请求体格式' });
}

4. 环境变量与参数校验 #

虽然你确认过AppID和证书正确，但仍需确保云函数能完整读取环境变量，且请求参数不缺失。

修复：
添加参数与环境变量校验：

if (!channelName || rawUid === undefined) {
  return res.status(400).json({ message: '缺少channelName或uid参数' });
}
if (!appId || !appCertificate) {
  error('环境变量APP_ID或APP_CERTIFICATE未配置');
  return res.status(500).json({ message: '服务器配置错误' });
}

修复后的完整代码 #

import pkg from 'agora-access-token';
const { RtcTokenBuilder, RtcRole } = pkg;

export default async ({ req, res, log, error }) => {
  if (req.method === 'POST') {
    let requestBody;
    try {
      requestBody = typeof req.body === 'string' ? JSON.parse(req.body) : req.body;
    } catch (parseErr) {
      error('请求体解析错误:', parseErr);
      return res.status(400).json({ message: '无效的请求体格式' });
    }

    const { channelName, uid: rawUid } = requestBody;
    if (!channelName || rawUid === undefined) {
      return res.status(400).json({ message: '缺少channelName或uid参数' });
    }

    const appId = process.env.APP_ID;
    const appCertificate = process.env.APP_CERTIFICATE;
    if (!appId || !appCertificate) {
      error('环境变量APP_ID或APP_CERTIFICATE未配置');
      return res.status(500).json({ message: '服务器配置错误' });
    }

    const role = RtcRole.PUBLISHER;
    const uid = parseInt(rawUid, 10);
    const finalUid = isNaN(uid) ? 0 : uid;
    const normalizedChannel = channelName.trim().toLowerCase();

    const expirationTimeInSeconds = 3600;
    const currentTimestamp = Math.floor(Date.now() / 1000);
    const privilegeExpiredTs = currentTimestamp + expirationTimeInSeconds;

    const token = RtcTokenBuilder.buildTokenWithUid(
      appId, 
      appCertificate, 
      normalizedChannel, 
      finalUid,
      role, 
      privilegeExpiredTs
    );

    log('生成Token成功：频道=', normalizedChannel, 'UID=', finalUid);
    return res.json({ token, uid: finalUid.toString() });
  } else {
    res.status(405).json({ message: '不允许的请求方法' });
  }
}

内容的提问来源于stack exchange，提问作者MaryKor