# FastAPI Users review: ready-made registration and auth for FastAPI

> FastAPI Users ships register, login, password reset, email verification and OAuth2 routes on top of FastAPI, with SQLAlchemy or Beanie behind them. It works, it is documented in detail, and since the README's own note it is in maintenance mode, which changes how you should plan around it.

**fastapi-users/fastapi-users** — Ready-to-use and customizable users management for FastAPI

- Repository: https://github.com/fastapi-users/fastapi-users
- Website: https://fastapi-users.github.io/fastapi-users/
- Stars: 6,248 · Forks: 511
- Language: Python
- License: MIT
- Published: 2026-09-22 · Updated: 2026-09-22 · Language: en
- Canonical page: https://hysenlabs.com/projects/fastapi-users-fastapi-users

## The boilerplate FastAPI Users removes, and who feels it most

A FastAPI service that needs accounts usually grows the same set of endpoints: register, login, logout, request a password reset, apply a password reset, request an email verification, apply it, and read the current user. Each one touches a database model, a password hasher, a token or session store, and a dependency that resolves the caller. FastAPI Users packages that set as routers you mount, plus a user manager you subclass. The audience is a backend team already committed to FastAPI and Starlette that would rather configure auth than write it. The README describes the project as "Ready-to-use and customizable users management for FastAPI", and the feature list backs that up: an extensible base user model, the register/login/reset/verify routes, a social OAuth2 login flow, dependency callables to inject the current user, and pluggable password validation. It is not an identity provider and not a hosted service. It is a Python package you install into your own application, which means your database, your email sending and your deployment stay yours.

## How the pieces fit: routers, manager, backends and transports

The architecture is layered, and the layers are the reason the library is configurable rather than opinionated. At the bottom sits a database adapter. The README lists SQLAlchemy ORM async and MongoDB with Beanie ODM as the included backends, and the repository keeps them in separate packages (fastapi_users_db_sqlalchemy and fastapi_users_db_beanie appear in the mypy overrides in pyproject.toml). Above that sits a user manager, which owns the logic for creating a user, validating a password, and issuing or consuming tokens. On top of the manager are routers: one for registration, one for authentication, one for reset, one for verification, one for users. The authentication layer is itself split into transports and strategies. Transports are where credentials arrive (the Authorization header or a cookie); strategies are how a session is represented (JWT, database, or Redis). Because these are separate choices, the same application can accept a bearer token on an API route and a cookie on a browser route, and the README claims full OpenAPI schema support even with several authentication backends mounted at once. The dependency callable is what route authors actually touch: you declare it as a parameter and receive the current user object, or a 401 if the request carries no valid credentials.

## Install and a first working route

There is no install command in the README itself. It points to the documentation site at fastapi-users.github.io/fastapi-users/ for setup instructions, and the repository ships four runnable examples under examples/: sqlalchemy, beanie, sqlalchemy-oauth and beanie-oauth. The pyproject.toml in the repository lists the features the maintainers test against, which tells you which extras exist: sqlalchemy, beanie, oauth and redis. A SQLAlchemy-backed application therefore needs the sqlalchemy extra, and a Beanie-backed one needs beanie; the bare package gives you the routers and the manager but no database adapter.

```toml
features = [
    "sqlalchemy",
    "beanie",
    "oauth",
    "redis",
]
```

That block is copied from the [tool.hatch.envs.default] section of pyproject.toml, where the project's own development environment declares the same four features. The examples directory is the fastest way to see the wiring end to end: each example is a small FastAPI app with a user model, a database adapter, a user manager and the mounted routers. The documentation's quickstart is where the user model and adapter are declared and the user manager is subclassed, and the routers are mounted from the FastAPIUsers object. Once mounted, the OpenAPI page should show the register, login, reset and verify paths, and calling login with a valid email and password should return a token that the configured transport accepts on later requests.

## Maintenance mode is the constraint that matters most

The README carries an explicit note: the project is in maintenance mode, security updates and dependency maintenance will continue, and no new features will be added. It also states that a new Python authentication toolkit is being worked on that will ultimately supersede FastAPI Users. That is an unusually clear signal, and it should drive the decision more than any feature comparison. For an application that needs exactly what the feature list already covers, maintenance mode is not a problem: the routes exist, the backends exist, and the last push to the repository was on 2026-08-17, so dependency and security work is still happening. The risk is directional. If your requirements drift toward something the library does not do today, you will be extending it yourself rather than waiting for a release. The recent release history is consistent with that posture: v15.0.5 in March 2026, v15.0.4 in February 2026, v15.0.3 in December 2025. Small, spaced patch releases, not a feature cadence.

## Where FastAPI Users is the wrong tool

The library assumes you own the user table. If your organisation already has an identity provider and you need to federate against it, the OAuth2 flow here is for social login, not for replacing an enterprise directory. The README's OAuth2 item is a social login flow, and the examples directory pairs it with both database backends (examples/sqlalchemy-oauth and examples/beanie-oauth), which tells you the intended shape: you keep local user records and attach an OAuth account to them. Teams that need SAML, SCIM provisioning or group-based authorisation will be building all of that outside the package. The second boundary is the database layer. Only SQLAlchemy async and Beanie are included as backends; the README describes the database backend as customizable, so a different store means writing an adapter against the project's own interface, which is real work and a real upgrade liability. Third, the library is deliberately unopinionated about email delivery. The reset and verification routes exist, but sending the message is your integration, and the documentation is where that contract lives. If you wanted a service that also sends the mail, this is not that.

## Alternatives and the actual difference in approach

The comparison people search for is FastAPI Users against Fief. The difference is architectural rather than a matter of taste. FastAPI Users is a library: it runs inside your process, uses your database session, and its routers are part of your OpenAPI schema. Fief is a separate authentication service, so user records live outside your application and your backend talks to it over HTTP, which removes the user table from your schema but adds a network dependency and a deployment to operate. That trade shows up in every decision afterwards. With FastAPI Users, a query that joins users to your domain tables is a normal query, and a schema migration is your migration. With a self-hosted auth service, the same join becomes an API call and the user identifier becomes a foreign key to something you do not control. Neither is better in the abstract. If you want auth to be a library call inside a FastAPI app you already run, FastAPI Users is the smaller commitment. If you want one auth system shared across services in several languages, the service model is the one that fits.

## Licence, upgrade cost and what to check before you commit

FastAPI Users is MIT licensed, which permits commercial use and modification with the licence and copyright notice retained. That is permissive, and it means the maintenance-mode note does not create a legal dead end: you can fork or vendor the package if you need to. The practical upgrade cost sits in the pieces you subclass. Your user model, your user manager and your database adapter are all code you own that depends on the library's interfaces. A patch release like v15.0.5 is unlikely to disturb them, but the interfaces are the contract, and the test suite in the repository is organised around markers for authentication, db, fastapi_users, jwt, manager, oauth, openapi and router, which is a fair map of the surface area a change can touch. Before adopting, check the extras you need against your Python version, confirm that the backend you intend to use is one of the two included, and read the documentation's section on the current_user dependency and the user manager, since that is where integration errors concentrate.

## Conclusion

Adopt FastAPI Users if you need standard email and password auth plus OAuth2 in a FastAPI service and you are fine with a library that only receives security and dependency updates. Do not adopt it if your roadmap depends on features it does not have yet, because the README states no new features will be added and a successor toolkit is being worked on. Before committing, verify the extras you need (sqlalchemy, beanie, oauth, redis) against your Python version, and read the current_user dependency and get_user_manager wiring in the docs, since that is where most integration mistakes happen.

## FAQ

### What is FastAPI Users in Python?

It is a Python package that adds user management to a FastAPI application: registration, login, password reset, email verification and social OAuth2 routes, plus a dependency that injects the current user into your own endpoints. It is a library you install into your app, not a separate service.

### How do I use FastAPI Users in a project?

You install it with an extra for your database backend, declare a user model and database adapter, subclass the user manager, and mount the routers. The README points to the documentation site for the full walkthrough and the repository keeps runnable examples under examples/sqlalchemy and examples/beanie.

### Is FastAPI Users good for a new project?

It covers standard email and password auth plus OAuth2 and is documented in detail, but the README states the project is in maintenance mode with no new features planned and a successor toolkit in development. That is acceptable if today's feature set is all you need, and a risk if your requirements will grow.

### How does FastAPI Users compare with Fief?

FastAPI Users is a library that runs inside your FastAPI process and uses your own database, so user records stay in your schema. Fief is a separate authentication service, so users live outside your application and your backend reaches it over HTTP. The choice is between a library dependency and an external service.

## Sources

- [fastapi-users/fastapi-users on GitHub](https://github.com/fastapi-users/fastapi-users)
- [License: MIT](https://github.com/fastapi-users/fastapi-users/blob/master/LICENSE)
- [Project website](https://fastapi-users.github.io/fastapi-users/)
- [README](https://github.com/fastapi-users/fastapi-users/blob/master/README.md)
- [Releases](https://github.com/fastapi-users/fastapi-users/releases)

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Hysen Labs editorial analysis, written from the project's own repository and release notes. Cite the canonical page: https://hysenlabs.com/projects/fastapi-users-fastapi-users