It brings the same **developer experience** of building apps with FastAPI to **deploying** them to the cloud. 🎉

It will also take care of most of the things you would need when deploying an app, like:

* HTTPS
* Replication, with autoscaling based on requests
* etc.

      add(notification);
    }
  }

  /**
   * {@link RemovalListener} that counts each {@link RemovalNotification} it receives, and provides
   * access to the most-recently received one.
   */
  static class CountingRemovalListener<K, V> implements RemovalListener<K, V> {
    private final AtomicInteger count = new AtomicInteger();

<img src="/img/tutorial/extending-openapi/image04.png">

## Change Default Swagger UI Parameters { #change-default-swagger-ui-parameters }

FastAPI includes some default configuration parameters appropriate for most of the use cases.

It includes these default configurations:

{* ../../fastapi/openapi/docs.py ln[9:24] hl[18:24] *}

You can override any of them by setting a different value in the argument `swagger_ui_parameters`.

        * So, the user will have to log in again at some point later.
        * And if the token is stolen, the risk is less. It is not like a permanent key that will work forever (in most of the cases).
* The frontend stores that token temporarily somewhere.
* The user clicks in the frontend to go to another section of the frontend web app.
* The frontend needs to fetch some more data from the API.

      }
    }
  }

  private fun ensureAllTaskQueuesIdle() {
    val entryTime = System.nanoTime()

    for (queue in TaskRunner.INSTANCE.activeQueues()) {
      // We wait at most 1 second, so we don't ever turn multiple lost threads into
      // a test timeout failure.
      val waitTime = (entryTime + 1_000_000_000L - System.nanoTime())
      if (!queue.idleLatch().await(waitTime, TimeUnit.NANOSECONDS)) {

import java.io.IOException;
import java.io.InputStream;
import java.util.Iterator;
import org.jspecify.annotations.Nullable;

/**
 * An {@link InputStream} that concatenates multiple substreams. At most one stream will be open at
 * a time.
 *
 * @author Chris Nokleberg
 * @since 1.0
 */
@J2ktIncompatible
@GwtIncompatible
final class MultiInputStream extends InputStream {

 * ```
 */
fun interface Interceptor {
  @Throws(IOException::class)
  fun intercept(chain: Chain): Response

  companion object {
    /**
     * Constructs an interceptor for a lambda. This compact syntax is most useful for inline
     * interceptors.
     *
     * ```kotlin
     * val interceptor = Interceptor { chain: Interceptor.Chain ->
     *     chain.proceed(chain.request())
     * }
     * ```
     */

import org.jspecify.annotations.Nullable;

/**
 * A {@link MapIteratorCache} that adds additional caching. In addition to the caching provided by
 * {@link MapIteratorCache}, this structure caches values for the two most recently retrieved keys.
 *
 * @author James Sexton
 */
final class MapRetrievalCache<K, V> extends MapIteratorCache<K, V> {
  // See the note about volatile in the superclass.

    @Override public Socket createSocket(
        Socket socket, String host, int port, boolean autoClose) throws IOException {
      return configureSocket((SSLSocket) delegate.createSocket(socket, host, port, autoClose));
    }

    @Override public Socket createSocket(String host, int port) throws IOException {
      return configureSocket((SSLSocket) delegate.createSocket(host, port));
    }

    @Override public Socket createSocket(

  }

  /**
   * Returns a new thread-safe interner which retains a weak reference to each instance it has
   * interned, and so does not prevent these instances from being garbage-collected. This most
   * likely does not perform as well as {@link #newStrongInterner}, but is the best alternative when
   * the memory usage of that implementation is unacceptable.
   */
  @GwtIncompatible("java.lang.ref.WeakReference")