L'utiliser dans votre éditeur est ce qui vous montre vraiment les avantages de FastAPI, en voyant le peu de code que vous avez à écrire, toutes les vérifications de type, l'autocomplétion, etc.

---

## Installer FastAPI

La première étape consiste à installer FastAPI.

Pour le tutoriel, vous voudrez peut-être l'installer avec toutes les dépendances et fonctionnalités optionnelles :

<div class="termy">

```console
$ pip install fastapi[all]

{
  "addIf": "true",
  "bridge": "mybridge",
  "ipMasq": true,
  "ipam": {
    "type": "host-local",
    "subnet": "10.1.0.0/16",
    "gateway": "10.1.0.1",
    "routes": [
      {
        "dst": "0.0.0.0/0"
      }
    ]
  },
  "isGateway": true,
  "mtu": 1460,
  "name": "rkt.kubernetes.io",
  "type": "bridge"

public class SynchronizedQueueTest extends TestCase {

  protected Queue<String> create() {
    TestQueue<String> inner = new TestQueue<>();
    Queue<String> outer = Synchronized.queue(inner, inner.mutex);
    outer.add("foo"); // necessary because we try to remove elements later on
    return outer;
  }

  private static final class TestQueue<E> implements Queue<E> {
    private final Queue<E> delegate = Lists.newLinkedList();

至此，在上文创建的回调路由里就包含了*回调路径操作*（外部开发者要在外部 API 中实现）。

现在使用 API *路径操作装饰器*的参数 `callbacks`，从回调路由传递属性 `.routes`（实际上只是路由/路径操作的**列表**）：

```Python hl_lines="36"
{!../../docs_src/openapi_callbacks/tutorial001.py!}
```

/// tip | "提示"

注意，不能把路由本身（`invoices_callback_router`）传递给 `callback=`，要传递 `invoices_callback_router.routes` 中的 `.routes` 属性。

///

### 查看文档

public class SynchronizedQueueTest extends TestCase {

  protected Queue<String> create() {
    TestQueue<String> inner = new TestQueue<>();
    Queue<String> outer = Synchronized.queue(inner, inner.mutex);
    outer.add("foo"); // necessary because we try to remove elements later on
    return outer;
  }

  private static final class TestQueue<E> implements Queue<E> {
    private final Queue<E> delegate = Lists.newLinkedList();

		lsrv := &lockServer{
			mutex:   sync.Mutex{},
			lockMap: make(map[string]int64),
		}
		lockServer := lockServerHandler{
			lsrv: lsrv,
		}
		lockServers[i] = lsrv

		router := mux.NewRouter().SkipClean(true)
		subrouter := router.PathPrefix("/").Subrouter()
		subrouter.Methods(http.MethodPost).Path("/v1/health").HandlerFunc(lockServer.HealthHandler)

🔜 ⚙️ 🔢 `callbacks` *👆 🛠️ ➡ 🛠️ 👨‍🎨* 🚶‍♀️ 🔢 `.routes` (👈 🤙 `list` 🛣/*➡ 🛠️*) ⚪️➡️ 👈 ⏲ 📻:

```Python hl_lines="35"
{!../../docs_src/openapi_callbacks/tutorial001.py!}
```

/// tip

👀 👈 👆 🚫 🚶‍♀️ 📻 ⚫️ (`invoices_callback_router`) `callback=`, ✋️ 🔢 `.routes`, `invoices_callback_router.routes`.

///

### ✅ 🩺

		t.Fatalf("Failed to create Comparator: %v", err)
	}
	err = comparator.Diff()
	if err != nil {
		t.Errorf("Unexpected error during diff: %v", err)
	}

	expected := []string{"Clusters Match", "Listeners Match", "Routes Match"}
	for _, exp := range expected {
		if !bytes.Contains(outputBuffer.Bytes(), []byte(exp)) {
			t.Errorf("Expected %s, but it was not found", exp)
		}
	}
}

```

## Benutzerdefinierte `APIRoute`-Klasse in einem Router

Sie können auch den Parameter `route_class` eines `APIRouter` festlegen:

```Python hl_lines="26"
{!../../docs_src/custom_request_and_route/tutorial003.py!}
```

def event_callback(event: Event):
    pass  # pragma: nocover


subrouter = APIRouter()


@subrouter.post("/invoices/", callbacks=invoices_callback_router.routes)
def create_invoice(invoice: Invoice, callback_url: Optional[HttpUrl] = None):
    """
    Create an invoice.

    This will (let's imagine) let the API user (some external developer) create an
    invoice.