También puedes retornar modelos de Pydantic (verás más sobre eso más adelante).

Hay muchos otros objetos y modelos que serán automáticamente convertidos a JSON (incluyendo ORMs, etc). Intenta usar tus favoritos, es altamente probable que ya sean compatibles.

## Recapitulación

* Importa `FastAPI`.
* Crea una instancia `app`.
* Escribe un **path operation decorator** usando decoradores como `@app.get("/")`.

browser("Browser")
proxy["Proxy on http://0.0.0.0:9999/api/v1/app"]
server["Server on http://127.0.0.1:8000/app"]

browser --> proxy
proxy --> server
```

/// tip

The IP `0.0.0.0` is commonly used to mean that the program listens on all the IPs available in that machine/server.

///

The docs UI would also need the OpenAPI schema to declare that this API `server` is located at `/api/v1` (behind the proxy). For example:

      ListenableFuture<? extends O> output = function.apply(input);
      checkNotNull(
          output,
          "AsyncFunction.apply returned null instead of a Future. "
              + "Did you mean to return immediateFuture(null)? %s",
          function);
      return output;
    }

    @Override
    void setResult(ListenableFuture<? extends O> result) {
      setFuture(result);
    }
  }

* The **HTTPS certificates** "certify" a **certain domain**, but the protocol and encryption happen at the TCP level, **before knowing** which domain is being dealt with.
* **By default**, that would mean that you can only have **one HTTPS certificate per IP address**.
    * No matter how big your server is or how small each application you have on it might be.
    * There is a **solution** to this, however.

they've begun asking riddles.--I believe I can guess that,' she
added aloud.

  `Do you mean that you think you can find out the answer to it?'
said the March Hare.

  `Exactly so,' said Alice.

  `Then you should say what you mean,' the March Hare went on.

  `I do,' Alice hastily replied; `at least--at least I mean what
I say--that's the same thing, you know.'

# ----------------------------------------------------------
# Hibernate Validator
# -------------------
constraints.CreditCardNumber.message = {item} ist eine ungültige Kreditkartennummer.
constraints.EAN.message = {item} ist ein ungültiger {type}-Barcode.
constraints.Email.message = {item} ist keine gültige E-Mail-Adresse.
constraints.Length.message = Die Länge von {item} muss zwischen {min} und {max} liegen.

    OVERREPORTING_SIZE_LIST = unmodifiableList(new MisleadingSizeList<>(collection123, 1));
  }

  /*
   * c.g.c.collect.testing.Helpers.misleadingSizeList has a broken Iterator, so we can't use it. (I
   * mean, ideally we'd fix it....) Also, we specifically need a List so that we trigger the fast
   * path in join(Iterable).
   */
  private static final class MisleadingSizeList<E extends @Nullable Object>

   * @param expectedCount the expected number of roundtrippable permutations
   * @param start the starting bytes encoded as a long as big-endian
   * @param lim the limit of bytes to process encoded as a long as big-endian, or -1 to mean the max
   *     limit for numBytes
   */
  @GwtIncompatible // java.nio.charset.Charset
  private static void testBytes(int numBytes, long expectedCount, long start, long lim) {
    byte[] bytes = new byte[numBytes];

 * your own escapers extend this class and implement the {@link #escape(int)} method.
 *
 * @author David Beaumont
 * @since 15.0
 */
@GwtCompatible
@SuppressWarnings("EscapedEntity") // We do mean for the user to see "<" etc.
public abstract class UnicodeEscaper extends Escaper {
  /** The amount of padding (chars) to use when growing the escape buffer. */
  private static final int DEST_PAD = 32;

 * your own escapers extend this class and implement the {@link #escape(int)} method.
 *
 * @author David Beaumont
 * @since 15.0
 */
@GwtCompatible
@SuppressWarnings("EscapedEntity") // We do mean for the user to see "<" etc.
public abstract class UnicodeEscaper extends Escaper {
  /** The amount of padding (chars) to use when growing the escape buffer. */
  private static final int DEST_PAD = 32;