Using Google Authentication API to Retrieve a User's Gmail Address

I’ve been learning about the Google Authentication API and I need assistance. After successfully authenticating a user, how can I obtain their Gmail address or any account details? Currently, I only receive an access token for the specified Google service but cannot find a straightforward method to retrieve the user’s email address. Also, which Google service supports accessing user information?

Hey Grace! You can get the user's email address by using the googleapis package's OAuth2 library. First, make sure you request the profile and email scopes. After authentication, use the access token to call the userinfo endpoint.

const { google } = require('googleapis');
const oauth2 = google.oauth2('v2');

oauth2.userinfo.get({
  auth: oauth2Client,
}, (err, res) => {
  if (err) return console.error(err);
  console.log(res.data.email); // User's email
});

This fetches the user's Gmail address and other available account details. Cheers!

Hi Grace! To fetch a user's Gmail address, you can follow actionable steps using Node.js and Google's OAuth2 library. Here is a streamlined approach:

1. Ensure your OAuth consent screen requests the necessary scopes like profile and email.

2. Use the googleapis package to access the userinfo endpoint after successful authentication. Here's a practical example:

const { google } = require('googleapis');
const oauth2Client = new google.auth.OAuth2(
  YOUR_CLIENT_ID,
  YOUR_CLIENT_SECRET,
  YOUR_REDIRECT_URL
);

// After obtaining the token
oauth2Client.setCredentials({ access_token: YOUR_ACCESS_TOKEN });

// Getting the user's email
const oauth2 = google.oauth2({ version: 'v2', auth: oauth2Client });
oauth2.userinfo.v2.me.get((err, res) => {
  if (err) {
    console.error('Error retrieving user info', err);
  } else {
    console.log('User email:', res.data.email);  // User's email
  }
});

This method efficiently retrieves the user's email, facilitating direct access to essential account details. Simplifying this process minimizes complexity and enhances workflow optimization. Hope this helps!

To efficiently fetch a user's Gmail address using the Google Authentication API, ensure you're requesting the profile and email scopes during the OAuth2 consent screen setup. Utilize the googleapis package to access the user's information.

const { google } = require('googleapis');

const oauth2Client = new google.auth.OAuth2(
  YOUR_CLIENT_ID,
  YOUR_CLIENT_SECRET,
  YOUR_REDIRECT_URL
);

// Set the token
oauth2Client.setCredentials({ access_token: YOUR_ACCESS_TOKEN });

// Get user's email
const oauth2 = google.oauth2({ version: 'v2', auth: oauth2Client });
oauth2.userinfo.get((err, res) => {
  if (err) return console.error(err);
  console.log(res.data.email); // User's email
});

This approach directly retrieves user info after authentication. Remember to handle errors and secure your application credentials properly.