## Adding ASGI middlewares { #adding-asgi-middlewares }

As **FastAPI** is based on Starlette and implements the <abbr title="Asynchronous Server Gateway Interface">ASGI</abbr> specification, you can use any ASGI middleware.

A middleware doesn't have to be made for FastAPI or Starlette to work, as long as it follows the ASGI spec.

### The callback path expression { #the-callback-path-expression }

### A expressão do path do callback { #the-callback-path-expression }

* [`Parameter Object` (в спецификации)](https://github.com/OAI/OpenAPI-Specification/blob/main/versions/3.1.0.md#parameter-object), которое использовалось в FastAPI:
    * `Path()`
    * `Query()`
    * `Header()`
    * `Cookie()`
* [`Request Body Object`, в поле `content`, в `Media Type Object` (в спецификации)](https://github.com/OAI/OpenAPI-Specification/blob/main/versions/3.1.0.md#media-type-object), которое использовалось в FastAPI:

レスポンスに正確に何を含められるかは、OpenAPI 仕様の次のセクションを参照してください:

- [OpenAPI の Responses Object](https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.1.0.md#responses-object)、ここには `Response Object` が含まれます。

          SSLContext.getInstance("TLS")
        }
      }
    }

  companion object {
    val isAvailable: Boolean

    val majorVersion = System.getProperty("java.specification.version")?.toIntOrNull()

    init {
      isAvailable =
        if (majorVersion != null) {
          majorVersion >= 9
        } else {
          try {
            // also present on JDK8 after build 252.

    int NT_STATUS_PATH_NOT_COVERED = 0xC0000257;
    /** The IO operation on the reparse point failed */
    int NT_STATUS_IO_REPARSE_TAG_NOT_HANDLED = 0xC0000279;
    /** No more files were found matching the file specification */
    int NT_STATUS_NO_MORE_FILES = 0x80000006;

    /** Array of all NT status codes defined in this interface */

アプリケーションで *path operation* を宣言すると、**FastAPI** はOpenAPIスキーマに含めるために、その *path operation* に関連するメタデータを自動的に生成します。

/// note | 技術詳細

OpenAPI仕様では [Operation Object](https://github.com/OAI/OpenAPI-Specification/blob/main/versions/3.0.3.md#operation-object) と呼ばれています。

///

これには *path operation* に関するすべての情報が含まれ、自動ドキュメントを生成するために使われます。

`tags`、`parameters`、`requestBody`、`responses` などが含まれます。

### Détails techniques : `root_path` { #technical-details-root-path }

Lorsque vous montez une sous‑application comme ci‑dessus, FastAPI se charge de communiquer le chemin de montage à la sous‑application au moyen d'un mécanisme de la spécification ASGI appelé `root_path`.

De cette manière, la sous‑application saura utiliser ce préfixe de chemin pour l'interface de documentation.

/**
 * An implementation of {@code Iterable} which throws an exception on all invocations of the {@link
 * #iterator()} method after the first, and whose iterator is always unmodifiable.
 *
 * <p>The {@code Iterable} specification does not make it absolutely clear what should happen on a
 * second invocation, so implementors have made various choices, including:
 *
 * <ul>
 *   <li>returning the same iterator again