A "bearer" token is not the only option.

    But it's the best one for our use case.

    And it might be the best for most use cases, unless you are an OAuth2 expert and know exactly why there's another option that suits better your needs.

    In that case, **FastAPI** also provides you with the tools to build it.

It is a project from the Linux Foundation. It provides **HTTPS certificates for free**, in an automated way. These certificates use all the standard cryptographic security, and are short-lived (about 3 months), so the **security is actually better** because of their reduced lifespan.

The domains are securely verified and the certificates are generated automatically. This also allows automating the renewal of these certificates.

    {!> ../../../docs_src/bigger_applications/app/dependencies.py!}
    ```

!!! tip
    We are using an invented header to simplify this example.

    But in real cases you will get better results using the integrated [Security utilities](security/index.md){.internal-link target=_blank}.

## Another module with `APIRouter`

## 0.101.0

### Features

* ✨ Enable Pydantic's serialization mode for responses, add support for Pydantic's `computed_field`, better OpenAPI for response models, proper required attributes, better generated clients. PR [#10011](https://github.com/tiangolo/fastapi/pull/10011) by [@tiangolo](https://github.com/tiangolo).

### Refactors

* Then check if the question (the vast majority are questions) is **clear**.

* In many cases the question asked is about an imaginary solution from the user, but there might be a **better** one. If you can understand the problem and use case better, you might be able to suggest a better **alternative solution**.

* If you can't understand the question, ask for more **details**.

### Reproduce the problem

## Future

By this point, it's already clear that **FastAPI** with its ideas is being useful for many people.

It is being chosen over previous alternatives for suiting many use cases better.

Many developers and teams already depend on **FastAPI** for their projects (including me and my team).

But still, there are many improvements and features to come.

**FastAPI** has a great future ahead.

!!! note
    FastAPI will know that the value of `q` is not required because of the default value `= None`.

    The `Union` in `Union[str, None]` will allow your editor to give you better support and detect errors.

## Additional validation

We are going to enforce that even though `q` is optional, whenever it is provided, **its length doesn't exceed 50 characters**.

### Import `Query` and `Annotated`

And these models are all sharing a lot of the data and duplicating attribute names and types.

We could do better.

We can declare a `UserBase` model that serves as a base for our other models. And then we can make subclasses of that model that inherit its attributes (type declarations, validation, etc).

### Tested

* 100% <abbr title="The amount of code that is automatically tested">test coverage</abbr>.
* 100% <abbr title="Python type annotations, with this your editor and external tools can give you better support">type annotated</abbr> code base.
* Used in production applications.

## Starlette features

### 💯

* 1️⃣0️⃣0️⃣ 💯 <abbr title="The amount of code that is automatically tested">💯 💰</abbr>.
* 1️⃣0️⃣0️⃣ 💯 <abbr title="Python type annotations, with this your editor and external tools can give you better support">🆎 ✍</abbr> 📟 🧢.
* ⚙️ 🏭 🈸.

## 💃 ⚒

**FastAPI** 🍕 🔗 ⏮️ (&amp; ⚓️ 🔛) <a href="https://www.starlette.io/" class="external-link" target="_blank"><strong>💃</strong></a>. , 🙆 🌖 💃 📟 👆 ✔️, 🔜 👷.