auth.py

from fusionauth.fusionauth_client import FusionAuthClient

class FusionAuthBackend:
  
    def authenticate(username: str, password: str, *args, **kwargs):
        # fusionauth_client.
        client = FusionAuthClient(settings.FUSION_AUTH_API_KEY, settings.FUSION_AUTH_BASE_URL)
        _tenant_id = settings.FUSION_AUTH_MAIN_TENANT_ID
        if _tenant_id != "":
            client.set_tenant_id(settings.FUSION_AUTH_MAIN_TENANT_ID)

        login_data = {
            "loginId": username,
            "password": password,
            "applicationId": settings.FUSION_AUTH_APP_ID,
            "noJWT": True,
        }

        response = client.login(login_data)
        _status = response.status
        if 200 >= _status <= 299:
            return get_or_create_user(response.success_response["user"]["email"])
        if _status > 299 :
            return None

fusion_utils.py

def get_or_create_user(user_id, first_name='', last_name='', middle_name='', *args, **kwargs):
    """
    Get or create a local user from fusionauth's information. Mostly used for local user federation.
    
    You can actually add more code here to support and make various authentication actions, for example 
    to implement a work around the fact that FA don't support yet users having more than one email address.
    
    :param user_id:
    :param first_name:
    :param last_name:
    :param middle_name:
    :return:
    """
    from django.db.models import Q
    User = get_user_model()
    user_qs = User.objects.filter(
        Q(email=user_id)
    )
    if user_qs.exists():
        return user_qs.first()
    # if not user:
    user = User(
        email=user_id , first_name=first_name ,
        last_name=last_name , **kwargs
    )
    # todo: create the mail here
    user.save()

    return user