anshupanthi01/auth-service ? reverse-engineered prompt

Build me a simple authentication service in Python that can handle sign up, sign in, sign out, and basic protected user access.

I want something I can run locally and extend later, with a clean structure, sensible defaults, and clear separation between the auth logic and the API layer. Include basic password handling, session or token based login, and a couple of endpoints that show how a logged in user would be verified. Add a small set of tests if it makes sense, and make sure the project is easy to start from the command line.

If you need to choose implementation details, keep them practical and common, and look up current docs online if you need to. Also add a short README that explains how to run it, how the auth flow works, and what I should change first if I want to plug it into a bigger app.