*    either peer may not have been transmitted to the other.
 *
 * Note that the state progression is independent for each peer. Arriving at a gracefully-closed
 * state indicates that a peer has sent all of its outgoing messages and received all of its
 * incoming messages. But it does not guarantee that the other peer will successfully receive all of
 * its incoming messages.
 *
 * ## Message Queue
 *

from fastapi import Depends, FastAPI

app = FastAPI()


def get_username():
    try:
        yield "Rick"
    finally:
        print("Cleanup up before response is sent")


@app.get("/users/me")
def get_user_me(username: str = Depends(get_username, scope="function")):

    * Étant donné que se connecter à un serveur et envoyer un email a tendance à être « lent » (plusieurs secondes), vous pouvez retourner la réponse directement et envoyer la notification en arrière-plan.
* Traiter des données :
    * Par exemple, si vous recevez un fichier qui doit passer par un traitement lent, vous pouvez retourner une réponse « Accepted » (HTTP 202) puis faire le traitement en arrière-plan.

You can declare a parameter in a *path operation function* or dependency function with the type `BackgroundTasks`, and then you can use it to schedule the execution of background tasks after the response is sent.

You can import it directly from `fastapi`:

```python
from fastapi import BackgroundTasks
```

@app.post("/send-notification/{email}")
async def send_notification(email: str, background_tasks: BackgroundTasks):
    background_tasks.add_task(write_notification, email, message="some notification")

Are you tired of all that **data validation**, **documentation**, **serialization**, and all that **boring** stuff?

Do you just want to **vibe**? 🎶

**FastAPI** now supports a new `@app.vibe()` decorator that embraces **modern AI coding best practices**. 🤖

## How It Works { #how-it-works }

The `@app.vibe()` decorator is intended to receive **any HTTP method** (`GET`, `POST`, `PUT`, `DELETE`, `PATCH`, etc.) and **any payload**.

API changes
-----------

We make changes to Guava's public [APIs][], including adding new APIs, very
carefully. Because of this, if you're interested in seeing a new feature in
Guava, the best approach is to create an [issue][] (or comment on an existing
issue if there is one) requesting the feature and describing specific use cases
for it.

If we decide to pursue a feature request, it will go through a thorough process

  private var failed = false

  /** Total number of pings sent by this web socket. */
  private var sentPingCount = 0

  /** Total number of pings received by this web socket. */
  private var receivedPingCount = 0

  /** Total number of pongs received by this web socket. */
  private var receivedPongCount = 0

  /** True if we have sent a ping that is still awaiting a reply. */
  private var awaitingPong = false

    public static final char MINUS_SIGN = '\u2212';

    /** FULLWIDTH HYPHEN-MINUS */
    public static final char FULLWIDTH_HYPHEN_MINUS = '\uFF0D';

    /** CENT SIGN */
    public static final char CENT_SIGN = '\u00A2';

    /** FULLWIDTH CENT SIGN */
    public static final char FULLWIDTH_CENT_SIGN = '\uFFE0';

    /** POUND SIGN */
    public static final char POUND_SIGN = '\u00A3';

    email: str, background_tasks: BackgroundTasks, q: Annotated[str, Depends(get_query)]
):
    message = f"message to {email}\n"
    background_tasks.add_task(write_log, message)