How Can I Retrieve and Store Access Tokens Using Django Allauth for Google Authentication?

When integrating Google authentication in a Django application using django-allauth, a common requirement is to access and store the user’s access token. This token is critical for interacting with Google services on behalf of the user. However, as I’ve found out through personal experience and numerous project implementations, django-allauth doesn’t handle token storage by default when setting up social authentication providers like Google. Let’s explore how to ensure that these tokens are not only retrieved but also stored correctly.

Understanding the Setup

Firstly, let’s take a look at the settings.py which is crucial for the authentication setup. The configuration for allauth and specifically for the Google provider is properly set. Here, the necessary scopes like email, profile, and specific Gmail permissions are requested:

SOCIALACCOUNT_PROVIDERS = {
    'google': {
        'SCOPE': [
            'profile',
            'email',
            'https://www.googleapis.com/auth/gmail.modify',
            'https://www.googleapis.com/auth/gmail.send',
        ],
        'AUTH_PARAMS': {
            'access_type': 'online',
        },
        'OAUTH_PKCE_ENABLED': True,
    }
}

Issue with Access Token Retrieval

Despite the correct setup, you might notice that the access token isn’t stored in the database which leads to the inability to make API calls on behalf of the user. django-allauth itself focuses more on the authentication part rather than handling token storage for API access.

Solution for Token Storage and Retrieval

To solve this problem, you need to ensure that the access tokens received from Google are saved for later use. This process involves a few steps:

1. Install Django Allauth Extensions:

If not already installed, you need an extension called django-allauth-socialaccount. This provides a table called SocialToken which is used to store tokens.

pip install django-allauth-socialaccount

Ensure it’s added to your INSTALLED_APPS in settings.py.

1. Signal to Capture and Store Tokens:

Django’s signal dispatcher can be used to capture the access token upon login. You’ll connect a function to Allauth’s social_account_updated signal which is triggered after a successful login.

First, import the required modules:

from allauth.socialaccount.models import SocialLogin, SocialToken
   from allauth.socialaccount.signals import social_account_updated
   from django.dispatch import receiver

Then, define a signal receiver function:

@receiver(social_account_updated)
   def retrieve_social_token(request, sociallogin, **kwargs):
       """
       Signal to capture the social token and save it when the social account is updated.
       """
       token = sociallogin.token.token
       # Now you can store this token in SocialToken model or your own custom model
       SocialToken.objects.create(
           app=sociallogin.account,
           token=token,
           account=sociallogin.account
       )

Make sure that you have also imported SocialToken from allauth.socialaccount.models.

1. Ensure Proper Redirects:

Verify that your LOGIN_REDIRECT_URL is correctly set in settings.py to direct users after logging in:

LOGIN_REDIRECT_URL = '/accounts/profile/'

Verifying Token Storage

Finally, after setting up the signal and ensuring that the SocialToken model (or any model you designate) is ready to store the tokens, run your application and authenticate using Google. The access tokens should now be captured and stored in your database, allowing you to use them for subsequent API calls.

This setup not only helps in storing the tokens but also facilitates a smoother integration with Google APIs, enhancing the functionality of your Django application.