python – Pydantic add field to model after a model validation (add filed to incoming model)

I have an incoming pydantic User model.
To add field after validation I’m converting it to dict and adding a field like for a regular dict.

user = employee.dict()
user.update({'invited_by': 'some_id'})
db.save(user)

Is there a shorter AND CLEANEST way to add a field? Because even for myself it’s no such clear, every time that I meeting this code (that wrote by myself) I thinking “Why I’m converting model to dict as separate instruction/line if I can do it inside save function (db.save(user))