* [Pull Request'ler oluşturuyor](help-fastapi.md#create-a-pull-request){.internal-link target=_blank}.
* Pull Request'leri gözden geçiriyorlar, [özellikle çeviriler için bu çok önemli](contributing.md#translations){.internal-link target=_blank}.

Onları bir alkışlayalım. 👏 🙇

## Geçen Ayın En Aktif Kullanıcıları

    pass


@app.post("/invoices/", callbacks=invoices_callback_router.routes)
def create_invoice(invoice: Invoice, callback_url: Union[HttpUrl, None] = None):
    """
    Create an invoice.

    This will (let's imagine) let the API user (some external developer) create an
    invoice.

    And this path operation will:

    * Send the invoice to the client.
    * Collect the money from the client.

* Nginx
* HAProxy

## Let's Encrypt

Before Let's Encrypt, these **HTTPS certificates** were sold by trusted third parties.

The process to acquire one of these certificates used to be cumbersome, require quite some paperwork and the certificates were quite expensive.

But then **<a href="https://letsencrypt.org/" class="external-link" target="_blank">Let's Encrypt</a>** was created.

# Security - First Steps

Let's imagine that you have your **backend** API in some domain.

And you have a **frontend** in another domain or in a different path of the same domain (or in a mobile application).

And you want to have a way for the frontend to authenticate with the backend, using a **username** and **password**.

We can use **OAuth2** to build that with **FastAPI**.

你可以用作 TLS 终止代理的一些选项包括：

* Traefik（也可以处理证书更新）
* Caddy（也可以处理证书更新）
* Nginx
* HAProxy

## Let's Encrypt

在 Let's Encrypt 之前，这些 **HTTPS 证书** 由受信任的第三方出售。

过去，获得这些证书的过程非常繁琐，需要大量的文书工作，而且证书非常昂贵。

但随后 **<a href="https://letsencrypt.org/" class="external-link" target="_blank">Let's Encrypt</a>** 创建了。

它是 Linux 基金会的一个项目。 它以自动方式免费提供 **HTTPS 证书**。 这些证书可以使用所有符合标准的安全加密，并且有效期很短（大约 3 个月），因此**安全性实际上更好**，因为它们的生命周期缩短了。

### Include an `APIRouter` with a custom `prefix`, `tags`, `responses`, and `dependencies`

Now, let's imagine your organization gave you the `app/internal/admin.py` file.

It contains an `APIRouter` with some admin *path operations* that your organization shares between several projects.

    {!> ../../../docs_src/python_types/tutorial008.py!}
    ```

This means:

* The variable `prices` is a `dict`:
    * The keys of this `dict` are of type `str` (let's say, the name of each item).
    * The values of this `dict` are of type `float` (let's say, the price of each item).

#### Union

You can declare that a variable can be any of **several types**, for example, an `int` or a `str`.

By considering these concepts, you will be able to **evaluate and design** the best way to deploy **your own APIs**.

In the next chapters, I'll give you more **concrete recipes** to deploy FastAPI applications.

But for now, let's check these important **conceptual ideas**. These concepts also apply to any other type of web API. 💡

## Security - HTTPS

### `User` model

First, let's create a `User` model:

```Python hl_lines="24-28"
{!../../../docs_src/nosql_databases/tutorial001.py!}
```

We will use this model in our *path operation function*, so, we don't include in it the `hashed_password`.

### `UserInDB` model

Now, let's create a `UserInDB` model.

This will have the data that is actually stored in the database.

But there are specific cases where it's useful to get the `Request` object.

## Use the `Request` object directly

Let's imagine you want to get the client's IP address/host inside of your *path operation function*.

For that you need to access the request directly.

```Python hl_lines="1  7-8"