Adding information to JWT token body using django rest framework jwt

Question

Im using django rest framework and the djangorestframework-jwt package to creat JWT tokens for authorization.

On the frontend I can decode the token and get the username, email and user_id. However I would like to retrieve some extra information. For example it would be very convenient if I could get kind which is a field on our authorization model (user model).

I can ofcourse make a separate request to get the user info via a regular APIView. But I'm wondering if it's possible to add some extra params in the JWT body?

Answer 1

Using the djangorestframework_simplejwt library

1. Specify in settings.py the USER_ID_FIELD and ALGORITHM

   SIMPLE_JWT = {
       'USER_ID_FIELD': 'user_id',
       'ALGORITHM': 'HS512',
   }
   

Let's say you want to add fields to the body of TokenObtainPairView which has the following body

{
    "refresh": "eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzUxMiJ9.eyJ0b2tlbl90eXBlIjoicmVmcmVzaCIsImV4cCI6MTU5MDk5ODAwMSwianRpIjoiMjZhZThhYTU4YTJiNDU3M2JlMDgxNTMzMzU1ODg4ZmUiLCJ1c2VyX2lkIjoxMX0.-jUCnfpTF-RsqHnuoEgctPpHf1SfYNcYaPs8oo01RvrQBMcyhms5PfWipfYkaR0FlPHSTKncNeMxomwd4k7nyg",
    "access": "eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzUxMiJ9.eyJ0b2tlbl90eXBlIjoiYWNjZXNzIiwiZXhwIjoxNTkwOTExOTAxLCJqdGkiOiI5NjZkOTFhNzEzNjg0NjMyOGUzYWU3NThiNzNiZmYxMyIsInVzZXJfaWQiOjExfQ.LiHrekmlHrM7_5187ghpIaA6mKcPCjDz4MDKPXHc4QAKVGvcJCJpCjrODCB4-pZn4Kuai5ht3YjWwYSirxpsXw"
}

2. Add in your urls.py

   path('api/token/', MyTokenObtainPairView.as_view(), name='token_obtain'),
   

3. Create the MyTokenObtainPairView

   class MyTokenObtainPairView(TokenObtainPairView):
       serializer_class = MyTokenObtainPairSerializer`
   

4. Create the MyTokenObtainPairSerializer

   class MyTokenObtainPairSerializer(TokenObtainPairSerializer):
       def validate(self, attrs):
           data = super().validate(attrs)
           refresh = self.get_token(self.user)
           data['refresh'] = str(refresh)
           data.pop('refresh', None) # remove refresh from the payload
           data['access'] = str(refresh.access_token)
   
           # Add extra responses here
           data['user'] = self.user.username
           data['kind'] = self.user.kind
           data['date'] = datetime.date.today()
           return data
   

This way when you post to /api/token/ you'll get in the body something like this

{
    "access": "eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzUxMiJ9.eyJ0b2tlbl90eXBlIjoiYWNjZXNzIiwiZXhwIjoxNTkwOTEwNTc0LCJqdGkiOiIwM2Q5MzA1NTZmNzk0NmFjODU1MzJlNTYzNjUwZDY0MCIsInVzZXJfaWQiOjExfQ.H0huO84qtzdbo4OkKhsW_vtNTGwInG67gum6f138h1y66EiyZ1BvxaxbfEE2oPG4pB0XjiWQrXc5PlR9C6UvfQ",
    "user": "tiago",
    "kind": "whatever_this_has"
    "date": "2020-05-31"
}

Answer 2

As detailed in this github issue, I did this by subclassinng the ObtainJSONWebToken class from DRF-JWT:

from rest_framework_jwt import views as jwt_views
from .serializers import UserSerializer 

class UserLoginViewJWT(jwt_views.ObtainJSONWebToken):
    user_serializer_class = UserSerializer

    def post(self, request, *args, **kwargs):
        response =  super().post(request, *args, **kwargs)

        if response.status_code == status.HTTP_200_OK:
            user = get_user_model().objects.get(email=request.data[get_user_model().USERNAME_FIELD])
            serialized_user = self.user_serializer_class(user)
            response.data.update(serialized_user.data)
        return response

Note: the code above is probably missing some imports

A reply from @jpadilla also specified that

You can also do this with the JWT_RESPONSE_PAYLOAD_HANDLER setting. http://getblimp.github.io/django-rest-framework-jwt/#jwt_response_payload_handler