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

!!! tip "Tipp"
    Beachten Sie, dass Sie nicht den Router selbst (`invoices_callback_router`) an `callback=` übergeben, sondern das Attribut `.routes`, wie in `invoices_callback_router.routes`.

### Es in der Dokumentation ansehen

import okhttp3.Response
import okhttp3.Route

class RecordingOkAuthenticator(
  val credential: String?,
  val scheme: String?,
) : Authenticator {
  val responses = mutableListOf<Response>()
  val routes = mutableListOf<Route>()

  fun onlyResponse() = responses.single()

  fun onlyRoute() = routes.single()

  @Throws(IOException::class)
  override fun authenticate(
    route: Route?,
    response: Response,

    http2Connection.start()
  }

  /**
   * Returns true if this connection can carry a stream allocation to `address`. If non-null
   * `route` is the resolved route for a connection.
   */
  internal fun isEligible(
    address: Address,
    routes: List<Route>?,
  ): Boolean {
    lock.assertHeld()

    // If this connection is not accepting new exchanges, we're done.

        val route = Route(address, proxy, inetSocketAddress)
        if (routeDatabase.shouldPostpone(route)) {
          postponedRoutes += route
        } else {
          routes += route
        }
      }

      if (routes.isNotEmpty()) {
        break
      }
    }

    if (routes.isEmpty()) {
      // We've exhausted all Proxies so fallback to the postponed routes.
      routes += postponedRoutes

  val failedRoutes: Set<Route>
    @Synchronized get() = _failedRoutes.toSet()

  /** Records a failure connecting to [failedRoute]. */
  @Synchronized fun failed(failedRoute: Route) {
    _failedRoutes.add(failedRoute)
  }

  /** Records success connecting to [route]. */
  @Synchronized fun connected(route: Route) {
    _failedRoutes.remove(route)
  }

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

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

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

### ✅ 🩺

  /** Returns a plan for the first attempt at [route]. This throws if no plan is possible. */
  @Throws(IOException::class)
  internal fun planConnectToRoute(
    route: Route,
    routes: List<Route>? = null,
  ): ConnectPlan {
    if (route.address.sslSocketFactory == null) {
      if (ConnectionSpec.CLEARTEXT !in route.address.connectionSpecs) {
        throw UnknownServiceException("CLEARTEXT communication not enabled for client")

   *
   * If [routes] is non-null these are the resolved routes (ie. IP addresses) for the connection.
   * This is used to coalesce related domains to the same HTTP/2 connection, such as `square.com`
   * and `square.ca`.
   */
  fun callAcquirePooledConnection(
    doExtensiveHealthChecks: Boolean,
    address: Address,
    connectionUser: ConnectionUser,
    routes: List<Route>?,

* `summary`: Eine kurze Zusammenfassung der API.
* `description`: Die Beschreibung Ihrer API. Dies kann Markdown enthalten und wird in der Dokumentation angezeigt.
* `routes`: Eine Liste von Routen, dies sind alle registrierten *Pfadoperationen*. Sie stammen von `app.routes`.

!!! info
    Der Parameter `summary` ist in OpenAPI 3.1.0 und höher verfügbar und wird von FastAPI 0.99.0 und höher unterstützt.

## Überschreiben der Standardeinstellungen

& 👈 🔢 `get_openapi()` 📨 🔢:

* `title`: 🗄 📛, 🎦 🩺.
* `version`: ⏬ 👆 🛠️, ✅ `2.5.0`.
* `openapi_version`: ⏬ 🗄 🔧 ⚙️. 🔢, ⏪: `3.0.2`.
* `description`: 📛 👆 🛠️.
* `routes`: 📇 🛣, 👫 🔠 ® *➡ 🛠️*. 👫 ✊ ⚪️➡️ `app.routes`.

## 🔑 🔢

⚙️ ℹ 🔛, 👆 💪 ⚙️ 🎏 🚙 🔢 🏗 🗄 🔗 & 🔐 🔠 🍕 👈 👆 💪.