Name Error: name 'User' is not defined. I cannot add my name to the userbase because of this error.

It's hard to tell without seeing everything, but if you're getting a User is not defined error, that's in regards to that User class. I would ensure that you're importing it correctly.

If you continue to be stuck on this, could you please provide all the code in this file and a link to the video please?

So, I notice some formatting errors and that the double underscores were set as bold text due to markdown, so I'm not 100% sure as I can't tell if the line spacing / indentation with your code was messed up when pasting it in to the forum here. In the future, since indentation and formatting is so critical in Python, I would wrap your code in a markdown code block. There's a link to a markdown cheatsheet near your text box here when writing a post or comment. 👍

Anyways, I still wasn't sure of the video / challenge this was in regards to but I hope that this may help.

from sqlalchemy import create_engine, Column, Integer, String
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker

engine = create_engine('sqlite:///users.db', echo=True)
Session = sessionmaker(bind=engine)
session = Session()
Base = declarative_base()

class User(Base):
    __tablename__ = 'users' 

    id = Column(Integer, primary_key=True)
    name = Column(String)
    fullname = Column(String)
    nickname = Column(String)

    def __repr__(self): 
        return f'<User(name={self.name}, fullname={self.fullname}, nickname={self.nickname})>'

if __name__ == "__main__":
    Base.metadata.create_all(engine)

    abi_user = User(name='Abigail', fullname='Abigail Solomon', nickname='Abi')

    print(abi_user.name)
    print(abi_user.id)  

    session.add(abi_user)
    print(session.new)  

I believe you are currently a Techdegree student right? I would definitely move to asking questions in Slack if so. You'll get much quicker replies and it's much easier to communicate / share code there 👍