* OpenAPIの *path operation* に、レスポンス用の **JSON Schema** を追加します。
    * これは**自動ドキュメント**で使用されます。
    * 自動クライアントコード生成ツールでも使用されます。
* 返却データを Pydantic を使ってJSONに**シリアライズ**します。Pydantic は内部が**Rust**で実装されているため、**非常に高速**です。

しかし、最も重要なのは:

* 戻り値の型で定義された内容に合わせて、出力データを**制限しフィルタリング**します。
    * これは**セキュリティ**の観点で特に重要です。以下で詳しく見ていきます。

## `response_model`パラメータ { #response-model-parameter }

## 0.123.2 (2025-12-02)

### Fixes

* 🐛 Fix unformatted `{type_}` in FastAPIError. PR [#14416](https://github.com/fastapi/fastapi/pull/14416) by [@Just-Helpful](https://github.com/Just-Helpful).
* 🐛 Fix parsing extra non-body parameter list. PR [#14356](https://github.com/fastapi/fastapi/pull/14356) by [@YuriiMotov](https://github.com/YuriiMotov).

   * {@code edge} will be undirected in this graph.
   *
   * <p>If this graph is directed, {@code endpoints} must be ordered.
   *
   * <p><b>{@code edge} must be unique to this graph</b>, just as a {@code Map} key must be. It must
   * also be non-null.
   *
   * <p>If either or both endpoints are not already present in this graph, this method will silently

   *     Queue<Integer>} but not a {@code Queue<Object>}).
   * @since 8.0
   */
  public static final class Builder<B> {
    /*
     * TODO(kevinb): when the dust settles, see if we still need this or can
     * just default to DEFAULT_CAPACITY.
     */
    private static final int UNSET_EXPECTED_SIZE = -1;

    private final Comparator<B> comparator;
    private int expectedSize = UNSET_EXPECTED_SIZE;

     * undirected, {@code edge} will be undirected in this network.
     *
     * <p>If this network is directed, {@code endpoints} must be ordered.
     *
     * <p><b>{@code edge} must be unique to this network</b>, just as a {@code Map} key must be. It
     * must also be non-null.
     *
     * <p>If either or both endpoints are not already present in this network, this method will

The spec also states that the `username` and `password` must be sent as form data (so, no JSON here).

### `scope` { #scope }

The spec also says that the client can send another form field "`scope`".

The form field name is `scope` (in singular), but it is actually a long string with "scopes" separated by spaces.

Each "scope" is just a string (without spaces).

    * A special case is `204`, "No Content".  This response is used when there is no content to return to the client, and so the response must not have a body.
* **`300 - 399`** are for "Redirection".  Responses with these status codes may or may not have a body, except for `304`, "Not Modified", which must not have one.
* **`400 - 499`** are for "Client error" responses. These are the second type you would probably use the most.

        // BooleanQueryCommand doesn't seem to apply boost correctly,
        // so we'll just check that it has clauses
        assertTrue(boolQueryBuilder.boost() > 0);
        // Check that the boolean query has the correct number of clauses
        assertFalse(boolQueryBuilder.must().isEmpty());
        assertFalse(boolQueryBuilder.should().isEmpty());
        assertFalse(boolQueryBuilder.mustNot().isEmpty());

   *     Queue<Integer>} but not a {@code Queue<Object>}).
   * @since 8.0
   */
  public static final class Builder<B> {
    /*
     * TODO(kevinb): when the dust settles, see if we still need this or can
     * just default to DEFAULT_CAPACITY.
     */
    private static final int UNSET_EXPECTED_SIZE = -1;

    private final Comparator<B> comparator;
    private int expectedSize = UNSET_EXPECTED_SIZE;

be able!  I shall be a great deal too far off to trouble myself
about you:  you must manage the best way you can; --but I must be
kind to them,' thought Alice, `or perhaps they won't walk the
way I want to go!  Let me see:  I'll give them a new pair of
boots every Christmas.'

  And she went on planning to herself how she would manage it.
`They must go by the carrier,' she thought; `and how funny it'll