If you pass a custom list of `servers` and there's a `root_path` (because your API lives behind a proxy), **FastAPI** will insert a "server" with this `root_path` at the beginning of the list.

For example:

```Python hl_lines="4-7"
{!../../../docs_src/behind_a_proxy/tutorial003.py!}
```

Will generate an OpenAPI schema like:

```JSON hl_lines="5-7"
{
    "openapi": "3.1.0",
    // More stuff here
    "servers": [

=== "Python 3.10+"

    ```Python hl_lines="16  21"
    {!> ../../../docs_src/response_model/tutorial001_01_py310.py!}
    ```

=== "Python 3.9+"

    ```Python hl_lines="18  23"
    {!> ../../../docs_src/response_model/tutorial001_01_py39.py!}
    ```

=== "Python 3.8+"

    ```Python hl_lines="18  23"

You can compare it with the *enumeration member* in your created enum `ModelName`:

```Python hl_lines="17"
{!../../../docs_src/path_params/tutorial005.py!}
```

#### Get the *enumeration value*

You can get the actual value (a `str` in this case) using `model_name.value`, or in general, `your_enum_member.value`:

```Python hl_lines="20"
{!../../../docs_src/path_params/tutorial005.py!}
```

!!! tip

## Recap

* Import `FastAPI`.
* Create an `app` instance.
* Write a **path operation decorator** (like `@app.get("/")`).
* Write a **path operation function** (like `def root(): ...` above).

## Generate a TypeScript Frontend Client

Let's start with a simple FastAPI application:

=== "Python 3.9+"

    ```Python hl_lines="7-9  12-13  16-17  21"
    {!> ../../../docs_src/generate_clients/tutorial001_py39.py!}
    ```

=== "Python 3.8+"

    ```Python hl_lines="9-11  14-15  18  19  23"
    {!> ../../../docs_src/generate_clients/tutorial001.py!}
    ```

    업로드된 파일들은 "폼 데이터"의 형태로 전송되기 때문에 이 작업이 필요합니다.

## `File` 임포트

`fastapi` 에서 `File` 과 `UploadFile` 을 임포트 합니다:

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

## `File` 매개변수 정의

`Body` 및 `Form` 과 동일한 방식으로 파일의 매개변수를 생성합니다:

```Python hl_lines="7"
{!../../../docs_src/request_files/tutorial001.py!}
```

!!! info "정보"
    `File` 은 `Form` 으로부터 직접 상속된 클래스입니다.

=== "🐍 3️⃣.6️⃣ & 🔛"

    ```Python hl_lines="9  17"
    {!> ../../../docs_src/request_files/tutorial001_02.py!}
    ```

=== "🐍 3️⃣.1️⃣0️⃣ & 🔛"

    ```Python hl_lines="7  14"
    {!> ../../../docs_src/request_files/tutorial001_02_py310.py!}
    ```

## `UploadFile` ⏮️ 🌖 🗃

👆 💪 ⚙️ `File()` ⏮️ `UploadFile`, 🖼, ⚒ 🌖 🗃:

```Python hl_lines="13"

    * So, by using FastAPI you are saving development time, bugs, lines of code, and you would probably get the same performance (or better) you would if you didn't use it (as you would have to implement it all in your code).

So we add that line here, with the new file.

```Python hl_lines="16"
{!../../../docs_src/sql_databases/sql_app/tests/test_sql_app.py!}
```

## Dependency override

Now we create the dependency override and add it to the overrides for our app.

```Python hl_lines="19-24  27"
{!../../../docs_src/sql_databases/sql_app/tests/test_sql_app.py!}
```

!!! tip

Any incoming requests to `http` or `ws` will be redirected to the secure scheme instead.

```Python hl_lines="2  6"
{!../../../docs_src/advanced_middleware/tutorial001.py!}
```

## `TrustedHostMiddleware`

Enforces that all incoming requests have a correctly set `Host` header, in order to guard against HTTP Host Header attacks.

```Python hl_lines="2  6-8"
{!../../../docs_src/advanced_middleware/tutorial002.py!}
```