```
https://yourapi.com/invoices/?callback_url=https://www.external.org/events
```

з JSON-тілом:

```JSON
{
    "id": "2expen51ve",
    "customer": "Mr. Richie Rich",
    "total": "9999"
}
```

тоді *ваш API* опрацює рахунок і згодом надішле запит зворотного виклику на `callback_url` ( *зовнішній API* ):

```
https://www.external.org/events/invoices/2expen51ve
```

з JSON-тілом на кшталт:

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.eventbus.outside;

import static com.google.common.truth.Truth.assertThat;

import com.google.common.eventbus.Subscribe;
import com.google.common.eventbus.outside.NeitherAbstractNorAnnotatedInSuperclassTest.SubClass;
import java.util.ArrayList;
import java.util.List;

        // Add events to buffer
        ComponentUtil.getLogNotificationHelper()
                .offer(new LogNotificationEvent(System.currentTimeMillis(), "ERROR", "org.test", "should remain", null));

        // expired() should skip when disabled
        logNotificationTarget.expired();

        // Buffer should still contain the event since disabled check should return early

 * the License.
 */

/**
 * {@linkplain EventBus Discouraged} in favor of dependency injection and concurrency frameworks,
 * EventBus allows publish-subscribe-style communication.
 *
 * <p>See the Guava User Guide article on <a
 * href="https://github.com/google/guava/wiki/EventBusExplained">{@code EventBus}</a>.
 */
@CheckReturnValue
@NullMarked
package com.google.common.eventbus;

  private final Object source;
  private final Object event;

  /**
   * Creates a new DeadEvent.
   *
   * @param source object broadcasting the DeadEvent (generally the {@link EventBus}).
   * @param event the event that could not be delivered.
   */
  public DeadEvent(Object source, Object event) {
    this.source = checkNotNull(source);
    this.event = checkNotNull(event);
  }

  /**

## Événements envoyés par le serveur (SSE) { #server-sent-events-sse }

    - advanced/middleware.md
    - advanced/sub-applications.md
    - advanced/behind-a-proxy.md
    - advanced/templates.md
    - advanced/websockets.md
    - advanced/events.md
    - advanced/testing-websockets.md
    - advanced/testing-events.md
    - advanced/testing-dependencies.md
    - advanced/async-tests.md
    - advanced/settings.md
    - advanced/openapi-callbacks.md
    - advanced/openapi-webhooks.md

async def sse_items_raw():
    yield ServerSentEvent(raw_data="plain text without quotes")
    yield ServerSentEvent(raw_data="<div>html fragment</div>", event="html")
    yield ServerSentEvent(raw_data="cpu,87.3,1709145600", event="csv")


router = APIRouter()


@router.get("/events", response_class=EventSourceResponse)
async def stream_events():
    yield {"msg": "hello"}
    yield {"msg": "world"}

https://yourapi.com/invoices/?callback_url=https://www.external.org/events
```

with a JSON body of:

```JSON
{
    "id": "2expen51ve",
    "customer": "Mr. Richie Rich",
    "total": "9999"
}
```

then *your API* will process the invoice, and at some point later, send a callback request to the `callback_url` (the *external API*):

```
https://www.external.org/events/invoices/2expen51ve
```

https://yourapi.com/invoices/?callback_url=https://www.external.org/events
```

com um corpo JSON de:

```JSON
{
    "id": "2expen51ve",
    "customer": "Mr. Richie Rich",
    "total": "9999"
}
```

então *sua API* processará a fatura e, em algum momento posterior, enviará um request de callback para o `callback_url` (a *API externa*):

```
https://www.external.org/events/invoices/2expen51ve
```