FastAPI використовує `.dict()` моделі Pydantic з <a href="https://docs.pydantic.dev/1.10/usage/exporting_models/#modeldict" class="external-link" target="_blank">параметром `exclude_unset`</a>, щоб досягти цього.

///

/// info | Інформація

Ви також можете використовувати:

* `response_model_exclude_defaults=True`
* `response_model_exclude_none=True`

次のようなJSONレスポンスが表示されます:

```JSON
{"message": "Hello World"}
```

### 対話的APIドキュメント

次に、<a href="http://127.0.0.1:8000/docs" class="external-link" target="_blank">http://127.0.0.1:8000/docs</a>にアクセスします。

自動生成された対話的APIドキュメントが表示されます (<a href="https://github.com/swagger-api/swagger-ui" class="external-link" target="_blank">Swagger UI</a>で提供):

import com.google.errorprone.annotations.CanIgnoreReturnValue;
import org.jspecify.annotations.Nullable;

/**
 * Static convenience methods that serve the same purpose as Java language <a
 * href="https://docs.oracle.com/javase/8/docs/technotes/guides/language/assert.html">assertions</a>,
 * except that they are always enabled. These methods should be used instead of Java assertions
 * whenever there is a chance the check may fail "in real life". Example:

        public ApiDocsResponse() {
            super();
        }

        /**
         * The list of documents returned in the search results.
         */
        protected List<Map<String, Object>> docs;
        /**
         * Parameters for highlighting search results.
         */
        protected String highlightParams;
        /**
         * The execution time of the search query.
         */

Auf diese Weise erhalten Sie das beste beider Welten: Sowohl Typannotationen mit **Tool-Unterstützung** als auch **Datenfilterung**.

## Anzeige in der Dokumentation { #see-it-in-the-docs }

Wenn Sie sich die automatische Dokumentation betrachten, können Sie sehen, dass Eingabe- und Ausgabemodell beide ihr eigenes JSON-Schema haben:

<img src="/img/tutorial/response-model/image01.png">

<div class="termy">

```console
$ fastapi dev main.py

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

</div>

Затем перейдите в UI `/docs`. Вы увидите, что **FastAPI** использует эти **модели** для **документирования** API, а также для **сериализации** и **валидации** данных.

<div class="screenshot">
<img src="/img/tutorial/sql-databases/image01.png">
</div>

Этого можно добиться, используя <a href="https://docs.pydantic.dev/latest/concepts/validators/#field-after-validator" class="external-link" target="_blank">`AfterValidator` Pydantic</a> внутри `Annotated`.

/// tip | Совет

Typically HTTP headers work like a `Map<String, String>`: each field has one value or none. But some headers permit multiple values, like Guava's [Multimap](https://guava.dev/releases/23.0/api/docs/com/google/common/collect/Multimap.html). For example, it's legal and common for an HTTP response to supply multiple `Vary` headers. OkHttp's APIs attempt to make both cases comfortable.

                || exception.getMessage().toLowerCase().contains("process"));
    }

    @Test
    @DisplayName("Should handle DOS error codes")
    void testDOSErrorCodes() {
        // Given
        int dosError = 0x00020002; // File not found from DOS_ERROR_CODES

        // When

- [Namespaced Brokers](https://svc-cat.io/docs/namespaced-broker-resources/), which enable operators to install a broker into a namespace instead of the cluster level, reached GA.