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

!!! note "Hinweis"
    Wenn Sie den Unterschied nicht kennen, lesen Sie [Async: *„In Eile?“*](../async.md#in-eile){.internal-link target=_blank}.

### Schritt 5: den Inhalt zurückgeben

```Python hl_lines="8"
{!../../../docs_src/first_steps/tutorial001.py!}
```

# First Steps

The simplest FastAPI file could look like this:

```Python
{!../../../docs_src/first_steps/tutorial001.py!}
```

Copy that to a file `main.py`.

Run the live server:

<div class="termy">

```console
$ <font color="#4E9A06">fastapi</font> dev <u style="text-decoration-style:single">main.py</u>
<font color="#3465A4">INFO    </font> Using path <font color="#3465A4">main.py</font>

```Python hl_lines="1"
{!../../../docs_src/first_steps/tutorial001.py!}
```

`FastAPI` 🐍 🎓 👈 🚚 🌐 🛠️ 👆 🛠️.

!!! note "📡 ℹ"
    `FastAPI` 🎓 👈 😖 🔗 ⚪️➡️ `Starlette`.

    👆 💪 ⚙️ 🌐 <a href="https://www.starlette.io/" class="external-link" target="_blank">💃</a> 🛠️ ⏮️ `FastAPI` 💁‍♂️.

### 🔁 2️⃣: ✍ `FastAPI` "👐"

```Python hl_lines="3"
{!../../../docs_src/first_steps/tutorial001.py!}
```

```Python hl_lines="1"
{!../../../docs_src/first_steps/tutorial001.py!}
```

`FastAPI`は、APIのすべての機能を提供するPythonクラスです。

!!! note "技術詳細"
    `FastAPI`は`Starlette`を直接継承するクラスです。

    `FastAPI`でも<a href="https://www.starlette.io/" class="external-link" target="_blank">Starlette</a>のすべての機能を利用可能です。

### Step 2: `FastAPI`の「インスタンス」を生成

```Python hl_lines="3"
{!../../../docs_src/first_steps/tutorial001.py!}
```

# 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**.

        },
        "german_keywords": {

Joshua Hanson <******@****.***> 1710356539 -0600

Nils Lindemann <******@****.***> 1713469999 +0200

Joshua Hanson <******@****.***> 1710356539 -0600

Joshua Hanson <******@****.***> 1710356539 -0600