Sebastián Ramírez <******@****.***> 1708815997 +0100

```Python hl_lines="2  12  15-18"
{!../../../docs_src/app_testing/tutorial001.py!}
```

!!! tip
    Notice that the testing functions are normal `def`, not `async def`.

    And the calls to the client are also normal calls, not using `await`.

    This allows you to use `pytest` directly without complications.

!!! note "Technical Details"

    Se você tem algum conhecimento técnico (corrotinas, threads, blocking etc) e está curioso sobre como o FastAPI controla o `async def` vs normal `def`, vá em frente.

### Funções de operação de rota

Quando você declara uma *função de operação de rota* com `def` normal ao invés de `async def`, ela é rodada em uma threadpool externa que então é aguardada, ao invés de ser chamada diretamente (ela poderia bloquear o servidor).

But if you go with your browser to <a href="http://127.0.0.1:8000" class="external-link" target="_blank">http://127.0.0.1:8000/app</a> you will see the normal response:

```JSON
{
    "message": "Hello World",
    "root_path": "/api/v1"
}
```

So, it won't expect to be accessed at `http://127.0.0.1:8000/api/v1/app`.

## Die normale **FastAPI**-Anwendung

Sehen wir uns zunächst an, wie die normale API-Anwendung aussehen würde, bevor wir den Callback hinzufügen.

Sie verfügt über eine *Pfadoperation*, die einen `Invoice`-Body empfängt, und einen Query-Parameter `callback_url`, der die URL für den Callback enthält.

Dieser Teil ist ziemlich normal, der größte Teil des Codes ist Ihnen wahrscheinlich bereits bekannt:

### Diğer yardımcı fonksiyonlar

Doğrudan çağırdığınız diğer herhangi bir yardımcı fonksiyonu, normal "def" veya "async def" ile tanimlayabilirsiniz. FastAPI onu çağırma şeklinizi etkilemez.

## The normal **FastAPI** app

Let's first see how the normal API app would look like before adding the callback.

It will have a *path operation* that will receive an `Invoice` body, and a query parameter `callback_url` that will contain the URL for the callback.

This part is pretty normal, most of the code is probably already familiar to you:

It will be called by **FastAPI** whenever it receives a request to the URL "`/`" using a `GET` operation.

In this case, it is an `async` function.

---

You could also define it as a normal function instead of `async def`:

```Python hl_lines="7"
{!../../../docs_src/first_steps/tutorial003.py!}
```

!!! note

Couchbase and we are not using the <a href="https://docs.couchbase.com/python-sdk/2.5/async-programming.html#asyncio-python-3-5" class="external-link" target="_blank">experimental Python <code>await</code> support</a>, we should declare our function with normal `def` instead of `async def`.

Also, Couchbase recommends not using a single `Bucket` object in multiple "<abbr title="A sequence of code being executed by the program, while at the same time, or at intervals, there can be others being executed...

# OpenAPI Webhooks

There are cases where you want to tell your API **users** that your app could call *their* app (sending a request) with some data, normally to **notify** of some type of **event**.

This means that instead of the normal process of your users sending requests to your API, it's **your API** (or your app) that could **send requests to their system** (to their API, their app).

This is normally called a **webhook**.

## Webhooks steps