class FormModelExtraAllow(BaseModel):
    param: str

    model_config = {"extra": "allow"}


@app.post("/form/")
def post_form(user: Annotated[FormModel, Form()]):
    return user


@app.post("/form-extra-allow/")
def post_form_extra_allow(params: Annotated[FormModelExtraAllow, Form()]):
    return params


client = TestClient(app)

* `allow_origin_regex` - A regex string to match against origins that should be permitted to make cross-origin requests. e.g. `'https://.*\.example\.org'`.
* `allow_methods` - A list of HTTP methods that should be allowed for cross-origin requests. Defaults to `['GET']`. You can use `['*']` to allow all standard methods.

        // Check all CORS headers are present
        assertNotNull(responseHeaders.get("Access-Control-Allow-Origin"), "Allow-Origin header should be set");
        assertNotNull(responseHeaders.get("Access-Control-Allow-Methods"), "Allow-Methods header should be set");
        assertNotNull(responseHeaders.get("Access-Control-Allow-Headers"), "Allow-Headers header should be set");

///

### Enable Proxy Forwarded Headers { #enable-proxy-forwarded-headers }

You can start FastAPI CLI with the *CLI Option* `--forwarded-allow-ips` and pass the IP addresses that should be trusted to read those forwarded headers.

If you set it to `--forwarded-allow-ips="*"` it would trust all the incoming IPs.

  /** The HTTP {@code Access-Control-Allow-Headers} header field name. */
  public static final String ACCESS_CONTROL_ALLOW_HEADERS = "Access-Control-Allow-Headers";

  /** The HTTP {@code Access-Control-Allow-Methods} header field name. */
  public static final String ACCESS_CONTROL_ALLOW_METHODS = "Access-Control-Allow-Methods";

  /** The HTTP {@code Access-Control-Allow-Origin} header field name. */

### 프록시 전달 헤더 활성화하기 { #enable-proxy-forwarded-headers }

FastAPI CLI를 *CLI 옵션* `--forwarded-allow-ips`로 실행하고, 전달 헤더를 읽을 수 있도록 신뢰할 IP 주소들을 넘길 수 있습니다.

`--forwarded-allow-ips="*"`로 설정하면 들어오는 모든 IP를 신뢰합니다.

**서버**가 신뢰할 수 있는 **프록시** 뒤에 있고 프록시만 서버에 접근한다면, 이는 해당 **프록시**의 IP가 무엇이든 간에 받아들이게 됩니다.

<div class="termy">

```console
$ fastapi run --forwarded-allow-ips="*"

 * user-defined properties.
 *
 * <p>A {@code Network} built by this class has the following default properties:
 *
 * <ul>
 *   <li>does not allow parallel edges
 *   <li>does not allow self-loops
 *   <li>orders {@link Network#nodes()} and {@link Network#edges()} in the order in which the
 *       elements were added (insertion order)
 * </ul>
 *

///

### 啟用代理轉發標頭 { #enable-proxy-forwarded-headers }

你可以在啟動 FastAPI CLI 時使用「CLI 選項」`--forwarded-allow-ips`，並傳入允許解析這些轉發標頭的受信任 IP 位址。

如果將其設為 `--forwarded-allow-ips="*"`，就會信任所有進來的 IP。

如果你的「伺服器」位於受信任的「代理」之後，且只有代理會與它通訊，這樣會讓它接受該「代理」的任何 IP。

<div class="termy">

```console
$ fastapi run --forwarded-allow-ips="*"

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)

    ValueGraphBuilder<N1, V1> castBuilder = cast();
    return new ImmutableValueGraph.Builder<>(castBuilder);
  }

  /**
   * Specifies whether the graph will allow self-loops (edges that connect a node to itself).
   * Attempting to add a self-loop to a graph that does not allow them will throw an {@link
   * UnsupportedOperationException}.
   *
   * <p>The default value is {@code false}.
   */
  @CanIgnoreReturnValue

### プロキシ転送ヘッダーを有効化 { #enable-proxy-forwarded-headers }

FastAPI CLI を *CLI オプション* `--forwarded-allow-ips` 付きで起動し、転送ヘッダーを信頼して読んでよい IP アドレスを指定できます。

`--forwarded-allow-ips="*"` とすると、すべての送信元 IP を信頼します。

**サーバー** が信頼できる **プロキシ** の背後にあり、そのプロキシからのみ接続される場合、プロキシの IP を受け入れるようになります。

<div class="termy">

```console
$ fastapi run --forwarded-allow-ips="*"