Cada ítem producido con `yield` se codifica como JSON y se envía en el campo `data:` de un evento SSE.

Si declaras el tipo de retorno como `AsyncIterable[Item]`, FastAPI lo usará para **validar**, **documentar** y **serializar** los datos usando Pydantic.

{* ../../docs_src/server_sent_events/tutorial001_py310.py ln[1:25] hl[10:12,23] *}

/// tip | Consejo

### Sin tipo de retorno { #no-return-type }

También puedes omitir el tipo de retorno. Entonces FastAPI usará [`jsonable_encoder`](./encoder.md) para convertir los datos a algo que se pueda serializar a JSON y luego enviarlo como JSON Lines.

{* ../../docs_src/stream_json_lines/tutorial001_py310.py ln[33:36] hl[34] *}

## Server-Sent Events (SSE) { #server-sent-events-sse }

import static com.google.common.collect.testing.testers.NavigableSetNavigationTester.getHoleMethods;
import static com.google.common.testing.SerializableTester.reserialize;
import static com.google.common.testing.SerializableTester.reserializeAndAssert;
import static com.google.common.truth.Truth.assertThat;

import com.google.common.annotations.GwtCompatible;

  virtual absl::Status AddDevices(
      std::vector<std::unique_ptr<Device>> devices) = 0;

  // Block until all pending nodes are finished.
  virtual absl::Status AsyncWait() = 0;

  // Add a function (serialized FunctionDef protocol buffer) so that it can
  // be executed as an op. Return error if the function with the same name
  // already exists.
  virtual absl::Status AddFunctionDef(const FunctionDef& fdef) = 0;

			return n, cr.err
		}
		if b == '\r' { // \r\n denotes end of size.
			err := mustRead('\n')
			if err != nil {
				cr.err = err
				return n, cr.err
			}
			break
		}

		// Manually deserialize the size since AWS specified
		// the chunk size to be of variable width. In particular,
		// a size of 16 is encoded as `10` while a size of 64 KB
		// is `10000`.
		switch {
		case b >= '0' && b <= '9':

Chaque élément produit avec `yield` est encodé en JSON et envoyé dans le champ `data:` d’un événement SSE.

Si vous déclarez le type de retour comme `AsyncIterable[Item]`, FastAPI l’utilisera pour **valider**, **documenter** et **sérialiser** les données avec Pydantic.

{* ../../docs_src/server_sent_events/tutorial001_py310.py ln[1:25] hl[10:12,23] *}

/// tip | Astuce

import static com.google.common.collect.ReflectionFreeAssertThrows.assertThrows;
import static com.google.common.collect.testing.Helpers.testComparator;
import static com.google.common.testing.SerializableTester.reserialize;
import static com.google.common.testing.SerializableTester.reserializeAndAssert;
import static com.google.common.truth.Truth.assertThat;
import static java.util.Arrays.asList;
import static java.util.Arrays.sort;

import static com.google.common.collect.ReflectionFreeAssertThrows.assertThrows;
import static com.google.common.collect.testing.Helpers.testComparator;
import static com.google.common.testing.SerializableTester.reserialize;
import static com.google.common.testing.SerializableTester.reserializeAndAssert;
import static com.google.common.truth.Truth.assertThat;
import static java.util.Arrays.asList;
import static java.util.Arrays.sort;

      hashCode = ~~hashCode;
      // needed to deal with GWT integer overflow
    }
    return hashCode;
  }

  /*
   * Serializes ImmutableLists as their logical contents. This ensures that
   * implementation types do not leak into the serialized representation.
   */
  @J2ktIncompatible // serialization
  static final class SerializedForm implements Serializable {
    final Object[] elements;

import java.util.concurrent.Callable;
import java.util.concurrent.Executor;
import java.util.concurrent.Future;
import java.util.concurrent.atomic.AtomicReference;
import org.jspecify.annotations.Nullable;

/**
 * Serializes execution of tasks, somewhat like an "asynchronous {@code synchronized} block." Each
 * {@linkplain #submit enqueued} callable will not be submitted to its associated executor until the