This would allow you to **re-use the model** in **multiple places** and also to declare validations and metadata for all the parameters at once. 😎

/// note

This is supported since FastAPI version `0.115.0`. 🤓

///

## Header Parameters with a Pydantic Model { #header-parameters-with-a-pydantic-model }

# Streaming

## Stream JSON Lines

To stream JSON Lines, declare the return type and use `yield` to return the data.

```python
@app.get("/items/stream")
async def stream_items() -> AsyncIterable[Item]:
    for item in items:
        yield item
```

## Server-Sent Events (SSE)

To stream Server-Sent Events, use `response_class=EventSourceResponse` and `yield` items from the endpoint.

With `Form` you can declare the same configurations as with `Body` (and `Query`, `Path`, `Cookie`), including validation, examples, an alias (e.g. `user-name` instead of `username`), etc.

/// info

`Form` is a class that inherits directly from `Body`.

///

/// tip

Et vous pouvez déclarer certains fichiers comme `bytes` et d'autres comme `UploadFile`.

/// warning | Alertes

# Cookie Parameter Models { #cookie-parameter-models }

If you have a group of **cookies** that are related, you can create a **Pydantic model** to declare them. 🍪

This would allow you to **re-use the model** in **multiple places** and also to declare validations and metadata for all the parameters at once. 😎

/// note

This is supported since FastAPI version `0.115.0`. 🤓

///

/// tip

# Declare Request Example Data { #declare-request-example-data }

You can declare examples of the data your app can receive.

Here are several ways to do it.

## Extra JSON Schema data in Pydantic models { #extra-json-schema-data-in-pydantic-models }

You can declare `examples` for a Pydantic model that will be added to the generated JSON Schema.

{* ../../docs_src/schema_extra_example/tutorial001_py310.py hl[13:24] *}

Nous pouvons faire mieux.

Nous pouvons déclarer un modèle `UserBase` qui sert de base à nos autres modèles. Ensuite, nous pouvons créer des sous-classes de ce modèle qui héritent de ses attributs (déclarations de type, validation, etc.).

Toutes les conversions de données, validations, documentation, etc., fonctionneront comme d'habitude.

## Additional Responses { #additional-responses }

You probably have seen how to declare the `response_model` and `status_code` for a *path operation*.

That defines the metadata about the main response of a *path operation*.

You can also declare additional responses with their models, status codes, etc.

El sistema de inyección de dependencias requiere pre-registrar las dependencias y las dependencias se resuelven en base a los tipos declarados. Por lo tanto, no es posible declarar más de un "componente" que proporcione cierto tipo.

   *
   * <p>Note that the specified object may not be known by the compiler to be a {@link
   * java.io.Serializable} instance, and is thus declared an {@code Object}. For example, it might
   * be declared as a {@code List}.
   *
   * @return the re-serialized object
   * @throws RuntimeException if the specified object was not successfully serialized or
   *     deserialized
   */