```Python hl_lines="9"
{!../../../docs_src/behind_a_proxy/tutorial004.py!}
```

and then it won't include it in the OpenAPI schema.

## Mounting a sub-application

If you need to mount a sub-application (as described in [Sub Applications - Mounts](sub-applications.md){.internal-link target=_blank}) while also using a proxy with `root_path`, you can do it normally, as you would expect.

* **Starlette** :
    * A les seconde meilleures performances après Uvicorn. Starlette utilise en réalité Uvicorn. De ce fait, il ne peut qu’être plus "lent" qu'Uvicorn car il requiert l'exécution de plus de code.
    * Cependant il nous apporte les outils pour construire une application web simple, avec un routage basé sur des chemins, etc.

You can add middleware to **FastAPI** applications.

A "middleware" is a function that works with every **request** before it is processed by any specific *path operation*. And also with every **response** before returning it.

* It takes each **request** that comes to your application.
* It can then do something to that **request** or run any needed code.
* Then it passes the **request** to be processed by the rest of the application (by some *path operation*).

# Reference - Code API

Here's the reference or code API, the classes, functions, parameters, attributes, and
all the FastAPI parts you can use in your applications.

If you want to **learn FastAPI** you are much better off reading the

```Python hl_lines="9  14"
{!../../../docs_src/dependencies/tutorial006.py!}
```

## 🔗 👪 *➡ 🛠️*

⏪, 🕐❔ 👂 🔃 ❔ 📊 🦏 🈸 ([🦏 🈸 - 💗 📁](../../tutorial/bigger-applications.md){.internal-link target=_blank}), 🎲 ⏮️ 💗 📁, 👆 🔜 💡 ❔ 📣 👁 `dependencies` 🔢 👪 *➡ 🛠️*.

## 🌐 🔗

"""FastAPI framework, high performance, easy to learn, fast to code, ready for production"""

__version__ = "0.111.0"

from starlette import status as status

from .applications import FastAPI as FastAPI
from .background import BackgroundTasks as BackgroundTasks
from .datastructures import UploadFile as UploadFile
from .exceptions import HTTPException as HTTPException
from .exceptions import WebSocketException as WebSocketException

    You could have custom internal logic to separate it by colon caracters (`:`) or
    similar, and get the two parts `items` and `read`. Many applications do that to
    group and organize permissions, you could do it as well in your application, just
    know that that it is application specific, it's not part of the specification.
    """

    def __init__(
        self,
        *,
        grant_type: Annotated[

```

[*路径装饰器依赖项*](dependencies-in-path-operation-decorators.md){.internal-link target=_blank} 一章的思路均适用于全局依赖项， 在本例中，这些依赖项可以用于应用中的所有*路径操作*。

## 为一组路径操作定义依赖项

As it is very simple, it's relatively intuitive to learn, although the documentation gets somewhat technical at some points.

It is also commonly used for other applications that don't necessarily need a database, user management, or any of the many features that come pre-built in Django. Although many of these features can be added with plug-ins.

                            "description": "Successful Response",
                            "content": {"application/json": {"schema": {}}},
                        },
                        "422": {
                            "description": "Validation Error",
                            "content": {
                                "application/json": {
                                    "schema": {