## About proxies with a stripped path prefix

Keep in mind that a proxy with stripped path prefix is only one of the ways to configure it.

Probably in many cases the default will be that the proxy doesn't have a stripped path prefix.

* **Uvicorn**:
    * Tendrá el mejor rendimiento, ya que no tiene mucho código extra aparte del propio servidor.

{!../../../docs_src/middleware/tutorial001.py!}
```

!!! tip
    Keep in mind that custom proprietary headers can be added <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers" class="external-link" target="_blank">using the 'X-' prefix</a>.

As the path of each *path operation* has to start with `/`, like in:

```Python hl_lines="1"
@router.get("/{item_id}")
async def read_item(item_id: str):
    ...
```

...the prefix must not include a final `/`.

So, the prefix in this case is `/items`.

We can also add a list of `tags` and extra `responses` that will be applied to all the *path operations* included in this router.

You will see the automatic API docs for the sub-application, including only its own _path operations_, all under the correct sub-path prefix `/subapi`:

<img src="/img/tutorial/sub-applications/image02.png">

If you try interacting with any of the two user interfaces, they will work correctly, because the browser will be able to talk to each specific app or sub-app.

    包含路由器时，你不必担心性能问题。

    这将花费几微秒时间，并且只会在启动时发生。

    因此，它不会影响性能。⚡

### 包含一个有自定义 `prefix`、`tags`、`responses` 和 `dependencies` 的 `APIRouter`

现在，假设你的组织为你提供了 `app/internal/admin.py` 文件。

它包含一个带有一些由你的组织在多个项目之间共享的管理员*路径操作*的 `APIRouter`。

对于此示例，它将非常简单。但是假设由于它是与组织中的其他项目所共享的，因此我们无法对其进行修改，以及直接在 `APIRouter` 中添加 `prefix`、`dependencies`、`tags` 等：

```Python hl_lines="3" title="app/internal/admin.py"

Bis hierher würde alles wie gewohnt funktionieren.

In those cases, several of those entities could have the same ID, let's say `foo` (a user `foo`, a car `foo`, and a blog post `foo`).

So, to avoid ID collisions, when creating the JWT token for the user, you could prefix the value of the `sub` key, e.g. with `username:`. So, in this example, the value of `sub` could have been: `username:johndoe`.

* `prefix`: to set the path prefix for a router. Up to now, this was only possible when calling `include_router`.
* `tags`: OpenAPI tags to apply to all the *path operations* in this router.

For example:

```Python
from fastapi import APIRouter, Depends


async def some_dependency():
    return

## Benutzerdefinierte Header

Beachten Sie, dass benutzerdefinierte proprietäre Header <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers" class="external-link" target="_blank">mittels des Präfix 'X-'</a> hinzugefügt werden können.