Por padrão, o **FastAPI** irá converter automaticamente o valor do retorno para JSON utilizando o `jsonable_encoder` explicado em [JSON Compatible Encoder](../tutorial/encoder.md){.internal-link target=_blank}.

Então, por baixo dos panos, ele incluiria esses dados compatíveis com JSON (e.g. um `dict`) dentro de uma `JSONResponse` que é utilizada para enviar uma resposta para o cliente.

	getNetInfoRPC                  = grid.NewSingleHandler[*grid.MSS, *grid.JSON[madmin.NetInfo]](grid.HandlerGetNetInfo, grid.NewMSS, madminNetInfo.NewJSON)
	getOSInfoRPC                   = grid.NewSingleHandler[*grid.MSS, *grid.JSON[madmin.OSInfo]](grid.HandlerGetOSInfo, grid.NewMSS, madminOSInfo.NewJSON)
	getPartitionsRPC               = grid.NewSingleHandler[*grid.MSS, *grid.JSON[madmin.Partitions]](grid.HandlerGetPartitions, grid.NewMSS, madminPartitions.NewJSON)

```JSON
{
  "item": "The Foo Wrestlers"
}
```

But if the client requests `http://example.com/items/bar` (a non-existent `item_id` `"bar"`), that client will receive an HTTP status code of 404 (the "not found" error), and a JSON response of:

```JSON
{
  "detail": "Item not found"
}
```

/// tip

package main

import (
	"encoding/json"
	"errors"
	"fmt"
	"log"
	"net/http"
)

func writeErrorResponse(w http.ResponseWriter, err error) {
	w.WriteHeader(http.StatusBadRequest)
	json.NewEncoder(w).Encode(map[string]string{
		"reason": fmt.Sprintf("%v", err),
	})
}

type Resp struct {
	User               string                 `json:"user"`

<div class="screenshot">
<img src="/img/tutorial/separate-openapi-schemas/image02.png">
</div>

Isso significa que ele **sempre terá um valor**, só que às vezes o valor pode ser `None` (ou `null` em termos de JSON).

Anda bisa menghasilkan *anggota enumerasi* dari *operasi path* bahkan di body JSON bersarang (contoh `dict`).

They will be converted to their corresponding values (strings in this case) before returning them to the client:

{* ../../docs_src/path_params/tutorial005.py hl[18,21,23] *}

Klien akan mendapatkan respon JSON seperti berikut:

```JSON
{
  "model_name": "alexnet",
  "message": "Deep Learning FTW!"
}
```

maven.installation.toolchains = ${maven.installation.conf}/toolchains.xml
maven.user.toolchains         = ${maven.user.conf}/toolchains.xml

#
# Extensions
#
maven.installation.extensions = ${maven.installation.conf}/extensions.xml
maven.project.extensions      = ${maven.project.conf}/extensions.xml
maven.user.extensions         = ${maven.user.conf}/extensions.xml

#
# Maven central repository URL.
#

Por exemplo, o modelo acima declara um JSON "`object`" (ou `dict` no Python) como esse:

```JSON
{
    "name": "Foo",
    "description": "Uma descrição opcional",
    "price": 45.2,
    "tax": 3.5
}
```

...como `description` e `tax` são opcionais (Com um valor padrão de `None`), esse JSON "`object`" também é válido:

```JSON
{
    "name": "Foo",
    "price": 45.2
}
```

	var sizes types.Sizes
	if w.context != nil {
		sizes = types.SizesFor(w.context.Compiler, w.context.GOARCH)
	}
	conf := types.Config{
		IgnoreFuncBodies: true,
		FakeImportC:      true,
		Importer:         w,
		Sizes:            sizes,
	}
	tpkg, err := conf.Check(name, fset, files, nil)
	if err != nil {
		ctxt := "<no context>"
		if w.context != nil {

Поля `example` как такового не существует в стандартах **JSON Schema**. В последних версиях JSON-схемы определено поле <a href="https://json-schema.org/draft/2019-09/json-schema-validation.html#rfc.section.9.5" class="external-link" target="_blank">`examples`</a>, но OpenAPI 3.0.3 основан на более старой версии JSON-схемы, которая не имела поля `examples`.