Python3 "Class factory" - ex: API(token).MyClass()

I'm writing a python REST client for an API.

The API needs authentication and I would like to have many API client objects running on the same script.

My current code for the API is something like this:

class RestAPI:
  def __init__(self, id):
    self.id = id
    self.fetch()

  def fetch(self):
    requests.get(self.url+self.id, auth=self.apikey)

class CustomModel(RestAPI):
  url = 'http://example.com/custommodel/'

And I would like to use the API like that:

api_admin = Api('adminmytoken')
api_user = Api('usertoken')
…
my_title = api_admin.CustomModel(2).Title

api_user.CustomModel(2).Title # raises because api_user is not authorized

The problem is that each object needs to know it's apikey depending on the client I want to use.

That pattern looks like to me to a "class factory": all the classes of RestAPI need to know of the provided token.

How is it possible to cleanly do that without giving manually the token to each model ?