Django, Djoser, Simple JWT, and Google Auth: Conquering the “Token has wrong type” Error

Are you tired of banging your head against the wall trying to fix the “Token has wrong type” error in your Django application? Look no further! In this comprehensive guide, we’ll take you by the hand and walk you through the process of setting up Django with Djoser, Simple JWT, and Google Auth. By the end of this article, you’ll be able to troubleshoot and fix this pesky error like a pro.

What is Djoser?

Djoser is a popular Django package that provides a RESTful API for user authentication and registration. It’s widely used in conjunction with Simple JWT, a token-based authentication system that allows users to access protected resources without having to re-enter their credentials.

What is Simple JWT?

Simple JWT is a lightweight token-based authentication system for Django. It’s designed to be simple, flexible, and easy to use. Simple JWT provides a set of views and serializers that can be used to issue and validate JSON Web Tokens (JWTs) for user authentication.

What is Google Auth?

Google Auth is a popular authentication service provided by Google that allows users to access multiple applications and services using their Google account. By integrating Google Auth with your Django application, you can provide a seamless and secure authentication experience for your users.

The “Token has wrong type” Error

The “Token has wrong type” error typically occurs when there is a mismatch between the type of token expected by the server and the type of token provided by the client. This error can be frustrating to troubleshoot, but don’t worry, we’ve got you covered.

Step 1: Install Required Packages

Before we dive into the setup process, make sure you have the following packages installed:

• Django (obviously!)
• Djoser
• Simple JWT
• django-rest-framework
• django-cors-headers (optional, but recommended)

pip install django djoser djangorestframework simplejwt django-cors-headers

Step 2: Configure Django Settings

In your Django settings file (settings.py), add the following configurations:

INSTALLED_APPS = [
    ...
    'rest_framework',
    'djoser',
    'simplejwt',
    ...
]

AUTHENTICATION_BACKENDS = [
    'django.contrib.auth.backends.ModelBackend',
]

SIMPLE_JWT = {
    'USER_ID_FIELD': 'id',
    'USER_ID_CLAIM': 'user_id',
}

DJOSER = {
    'PASSWORD_RESET_CONFIRM_URL': 'password/reset/confirm/{uid}/{token}',
    'USERNAME_RESET_CONFIRM_URL': 'email/reset/confirm/{uid}/{token}',
    'ACTIVATION_URL': 'activate/{uid}/{token}',
    'SEND_ACTIVATION_EMAIL': True,
    'SEND_CONFIRMATION_EMAIL': True,
}

JWT_AUTH = {
    'JWT_ENCODE_HANDLER':
        'rest_framework_jwt.utils.jwt_encode_handler',
    'JWT_DECODE_HANDLER':
        'rest_framework_jwt.utils.jwt_decode_handler',
    'JWT_PAYLOAD_HANDLER':
        'rest_framework_jwt.utils.jwt_payload_handler',
    'JWT_PAYLOAD_GET_USER_ID_HANDLER':
        'rest_framework_jwt.utils.jwt_get_user_id_from_payload_handler',
    'JWT_PUBLIC_KEY': None,
    'JWT_PRIVATE_KEY': None,
    'JWT_ALGORITHM': 'HS256',
    'JWT_VERIFY': True,
    'JWT_VERIFY_EXPIRATION': True,
    'JWT_LEEWAY': 0,
    'JWT_EXPIRATION_DELTA': datetime.timedelta(seconds=300),
    'JWT_AUDIENCE': None,
    'JWT_ISSUER': None,
}

Step 3: Create a Custom User Model

Create a new file called models.py and add the following code:

from django.db import models
from django.contrib.auth.models import AbstractUser

class CustomUser(AbstractUser):
    email = models.EmailField(unique=True)

In your Django settings file, add the following configuration:

AUTH_USER_MODEL = 'your_app_name.CustomUser'

Step 4: Implement Google Auth

Create a new file called views.py and add the following code:

from rest_framework.response import Response
from rest_framework.views import APIView
from django.contrib.auth import login
from djoser.views import TokenDestroyView
from djoser import serializers
from .models import CustomUser
import google.oauth2.credentials
import google_auth_oauthlib.flow
import requests
from datetime import datetime, timedelta

class GoogleAuthView(APIView):
    def post(self, request):
        code = request.data.get('code')
        if not code:
            return Response({'error': 'No code provided'}, status=400)

        flow = google_auth_oauthlib.flow.Flow.from_client_secrets_file(
            'credentials.json',
            scopes=['openid', 'email', 'profile']
        )
        flow.redirect_uri = 'postmessage'

        authorization_response = request.data.get('redirectUri')
        flow.fetch_token(authorization_response=authorization_response)

        credentials = flow.credentials
        token_response = requests.post(
            'https://oauth2.googleapis.com/token',
            headers={
                'Content-Type': 'application/x-www-form-urlencoded'
            },
            data={
                'grant_type': 'authorization_code',
                'code': code,
                'redirect_uri': 'postmessage',
                'client_id': 'your_client_id',
                'client_secret': 'your_client_secret'
            }
        )

        token_data = token_response.json()
        id_token = token_data.get('id_token')

        if not id_token:
            return Response({'error': 'Failed to authenticate with Google'}, status=401)

        user_data = google.oauth2.credentials.Credentials.get_id_token_credentials(
            id_token
        ).verified_id_token.claims

        user, created = CustomUser.objects.get_or_create(
            email=user_data.get('email')
        )
        user.username = user_data.get('email')
        user.save()

        login(request, user)

        djoser_token = serializers.TokenSerializer(data={'token': token_data.get('access_token')})
        djoser_token.is_valid(raise_exception=True)

        return Response(djoser_token.validated_data, status=200)

In the code above, replace 'your_client_id' and 'your_client_secret' with your actual Google OAuth client ID and secret.

Step 5: Configure URLs

Create a new file called urls.py and add the following code:

from django.urls import path, include
from rest_framework.routers import DefaultRouter
from .views import GoogleAuthView

router = DefaultRouter()
router.register(r'google-auth', GoogleAuthView, basename='google-auth')

urlpatterns = [
    path('', include(router.urls)),
    path('auth/', include('djoser.urls')),
    path('auth/', include('rest_framework.urls')),
]

Troubleshooting the “Token has wrong type” Error

If you’re still experiencing the “Token has wrong type” error, try the following:

• Check that you’re using the correct token type (e.g., Bearer or JWT) in your API requests.
• Verify that your token is properly encoded and decoded using Simple JWT’s jwt_encode_handler and jwt_decode_handler functions.
• Ensure that your Django settings are correctly configured, particularly the SIMPLE_JWT and DJOSER settings.
• Check that your custom user model is properly defined and registered in your Django settings.
• If using Google Auth, verify that your OAuth client ID and secret are correctly configured.

Conclusion

And that’s it! By following these steps, you should now have a fully functional Django application with Djoser, Simple JWT, and Google Auth integration. Remember to troubleshoot the “Token has wrong type” error by checking your token type, encoding and decoding, Django settings, custom user model, and OAuth client ID and secret. If you’re still experiencing issues, feel free to drop a comment below and we’ll do our best to help you out.

Happy coding!

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