Gmail Get Auth Token

gmail_auth.js

/*
  https://medium.com/@andrea_j24/come-trasformare-le-email-in-richieste-http-84c178480d1f
  
  npm install google-auth-library readline
  node gmail_auth.js
*/
var googleAuth = require('google-auth-library');
var readline = require('readline');

// See scopes : https://developers.google.com/gmail/api/auth/scopes
var SCOPES = ["https://mail.google.com/"];

/**
 * Create an OAuth2 client with the given credentials
 * @param {Object} credentials The authorization client credentials.
 */
function authorize(credentials) {
  var clientSecret = "YOUR_clientSecret";
  var clientId = "YOUR_clientId";
  var redirectUrl = "http://localhost:3000";
  var auth = new googleAuth();
  var oauth2Client = new auth.OAuth2(clientId, clientSecret, redirectUrl);
  getNewToken(oauth2Client);
}


/**
 * Get  new token after prompting for user authorization, and then
 * execute the given callback with the authorized OAuth2 client.
 *
 * @param {google.auth.OAuth2} oauth2Client The OAuth2 client to get token for.
 */
function getNewToken(oauth2Client, callback) {
  var authUrl = oauth2Client.generateAuthUrl({
    access_type: 'offline',
    scope: SCOPES
  });
  console.log('Authorize this app by visiting this url: ', authUrl);
  var rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout
  });
  rl.question('Enter the code from that page here: ', function(code) {
    rl.close();
    oauth2Client.getToken(code, function(err, token) {
      if (err) {
        console.log('Error while trying to retrieve access token', err);
        return;
      }
      console.log("token= " ,token);
    });
  });
}

// Start
authorize();