* Il y a un sous-répertoire `app/routers/` avec un autre fichier `__init__.py`, c'est donc un « sous-package Python » : `app.routers`.
* Le fichier `app/routers/items.py` est dans un package, `app/routers/`, c'est donc un sous-module : `app.routers.items`.
* De même pour `app/routers/users.py`, c'est un autre sous-module : `app.routers.users`.

    response = client_nested.post("/outer/strict/items/", json={"key": "value"})
    assert response.status_code == 200


def test_default_inner_accepts_json_content_type():
    response = client_nested.post("/outer/default/items/", json={"key": "value"})
    assert response.status_code == 200


# Strict app -> lax outer router -> strict inner router

app_mixed = FastAPI(strict_content_type=True)

* There's a subdirectory `app/routers/` with another file `__init__.py`, so it's a "Python subpackage": `app.routers`.
* The file `app/routers/items.py` is inside a package, `app/routers/`, so, it's a submodule: `app.routers.items`.
* The same with `app/routers/users.py`, it's another submodule: `app.routers.users`.

{* ../../docs_src/openapi_callbacks/tutorial001_py310.py hl[33] *}

/// tip | Tipp

Beachten Sie, dass Sie nicht den Router selbst (`invoices_callback_router`) an `callback=` übergeben, sondern das Attribut `.routes`, wie in `invoices_callback_router.routes`.

///

### Es in der Dokumentation testen { #check-the-docs }

* 還有一個 `app/dependencies.py` 檔案，就像 `app/main.py` 一樣，它是一個「模組」：`app.dependencies`。
* 有一個子目錄 `app/routers/`，裡面有另一個 `__init__.py` 檔案，所以它是一個「Python 子套件」：`app.routers`。
* 檔案 `app/routers/items.py` 在一個套件 `app/routers/` 內，因此它是一個子模組：`app.routers.items`。
* 同樣地，`app/routers/users.py` 是另一個子模組：`app.routers.users`。
* 還有一個子目錄 `app/internal/`，裡面有另一個 `__init__.py` 檔案，所以它又是一個「Python 子套件」：`app.internal`。

* `app/routers/` adında bir alt dizin vardır ve içinde başka bir `__init__.py` dosyası bulunur; dolayısıyla bu bir "Python subpackage"’dir: `app.routers`.
* `app/routers/items.py` dosyası `app/routers/` package’i içinde olduğundan bir submodule’dür: `app.routers.items`.
* `app/routers/users.py` için de aynı şekilde, başka bir submodule’dür: `app.routers.users`.

* Hay un subdirectorio `app/routers/` con otro archivo `__init__.py`, por lo que es un "subpaquete de Python": `app.routers`.
* El archivo `app/routers/items.py` está dentro de un paquete, `app/routers/`, por lo que es un submódulo: `app.routers.items`.
* Lo mismo con `app/routers/users.py`, es otro submódulo: `app.routers.users`.

* Há um subdiretório `app/routers/` com outro arquivo `__init__.py`, então ele é um "subpacote Python": `app.routers`.
* O arquivo `app/routers/items.py` está dentro de um pacote, `app/routers/`, portanto é um submódulo: `app.routers.items`.
* O mesmo com `app/routers/users.py`, ele é outro submódulo: `app.routers.users`.

[providers]
  [providers.file]
    filename = "routes.toml"
```

Cela indique à Traefik d'écouter sur le port 9999 et d'utiliser un autre fichier `routes.toml`.

/// tip | Astuce

Nous utilisons le port 9999 au lieu du port HTTP standard 80 afin que vous n'ayez pas à l'exécuter avec des privilèges administrateur (`sudo`).

///

Créez maintenant cet autre fichier `routes.toml` :

```TOML hl_lines="5  12  20"

///

### Add the callback router { #add-the-callback-router }

At this point you have the *callback path operation(s)* needed (the one(s) that the *external developer*  should implement in the *external API*) in the callback router you created above.

Now use the parameter `callbacks` in *your API's path operation decorator* to pass the attribute `.routes` (that's actually just a `list` of routes/*path operations*) from that callback router: