You can import it directly from `fastapi`:

```python
from fastapi import Request
```

!!! tip
    When you want to define dependencies that should be compatible with both HTTP and WebSockets, you can define a parameter that takes an `HTTPConnection` instead of a `Request` or a `WebSocket`.

## Conception

Ensuite, j'ai passé du temps à concevoir l'"API" de développeur que je voulais avoir en tant qu'utilisateur (en tant que développeur utilisant FastAPI).

J'ai testé plusieurs idées dans les éditeurs Python les plus populaires : PyCharm, VS Code, les éditeurs basés sur Jedi.

    **FastAPI** provides the same `starlette.testclient` as `fastapi.testclient` just as a convenience for you, the developer. But it comes directly from Starlette.

!!! tip

But if you want to directly use **Trio**, then you can use **Hypercorn** as it supports it. ✨

### Install Hypercorn with Trio

First you need to install Hypercorn with Trio support:

<div class="termy">

```console

{!../../../docs_src/path_params/tutorial003b.py!}
```

The first one will always be used since the path matches first.

## Predefined values

If you have a *path operation* that receives a *path parameter*, but you want the possible valid *path parameter* values to be predefined, you can use a standard Python <abbr title="Enumeration">`Enum`</abbr>.

### Create an `Enum` class

In some cases, you may want to override the logic used by the `Request` and `APIRoute` classes.

In particular, this may be a good alternative to logic in a middleware.

For example, if you want to read or manipulate the request body before it is processed by your application.

!!! danger
    This is an "advanced" feature.

    If you are just starting with **FastAPI** you might want to skip this section.

## Use cases

It is provided directly by Starlette, but you can import it from `fastapi`:

```python
from fastapi import WebSocket
```

!!! tip
    When you want to define dependencies that should be compatible with both HTTP and WebSockets, you can define a parameter that takes an `HTTPConnection` instead of a `Request` or a `WebSocket`.

::: fastapi.WebSocket
    options:

* MySQL
* SQLite

In this example, we'll use **SQLite**, because it uses a single file and Python has integrated support. So, you can copy this example and run it as is.

Later, for your production application, you might want to use a database server like **PostgreSQL**.

!!! tip

...But here I want to show you the community.

---

**FastAPI** receives a lot of support from the community. And I want to highlight their contributions.

These are the people that:

But you can configure it with the parameter `openapi_url`.

For example, to set it to be served at `/api/v1/openapi.json`:

```Python hl_lines="3"
{!../../../docs_src/metadata/tutorial002.py!}
```

If you want to disable the OpenAPI schema completely you can set `openapi_url=None`, that will also disable the documentation user interfaces that use it.

## Docs URLs

You can configure the two documentation user interfaces included: