SuperTokens is an open source authentication solution offering features like: Different types of login: Email / password, Passwordless (OTP or Magic link based).

SuperTokens.com

app.post('/api/auth/signin', function (req, res) {
  //const user = req.body.username;
  //const pwd = req.body.password;
  
  const user = req.body.formFields[0].value;
  const pwd = req.body.formFields[1].value;

  // return 400 status if username/password is not exist
  if (!user || !pwd) {
    return handleResponse(req, res, 400, null, "Username and Password required.");
  }

  const userData = userList.find(x => x.username === user && x.password === pwd);
  

  // return 401 status if the credential is not matched
  if (!userData) {
    return handleResponse(req, res, 401, null, "Username or Password is Wrong.");
  }

  // get basic user details
  const userObj = getCleanUser(userData);
  
  

  // generate access token
  const tokenObj = generateToken(userData);

  // generate refresh token
  const refreshToken = generateRefreshToken(userObj.userId);

  // refresh token list to manage the xsrf token
  refreshTokens[refreshToken] = tokenObj.xsrfToken;

  // set cookies
  res.cookie('refreshToken', refreshToken, COOKIE_OPTIONS);
  res.cookie('XSRF-TOKEN', tokenObj.xsrfToken);

  return handleResponse(req, res, 200, {
    user: userObj,
    token: tokenObj.token,
    expiredAt: tokenObj.expiredAt
  });
});