│                          │
 │  <span style="background-color:#272822"><font color="#FF4689">from</font></span><span style="background-color:#272822"><font color="#F8F8F2"> main </font></span><span style="background-color:#272822"><font color="#FF4689">import</font></span><span style="background-color:#272822"><font color="#F8F8F2"> app</font></span><span style="background-color:#272822">  </span>  │
 │                          │

* Hỗ trợ **WebSocket**.
* In-process background tasks.
* Startup and shutdown events.
* Client cho kiểm thử xây dựng trên HTTPX.
* **CORS**, GZip, Static Files, Streaming responses.
* Hỗ trợ **Session and Cookie**.
* 100% test coverage.

Nevertheless, as this would mean waiting for the response to travel through the network while unnecessarily holding a resource in a dependency with yield (for example a database connection), this was changed in FastAPI 0.106.0.

!!! tip

        values[dependant.websocket_param_name] = request
    if dependant.background_tasks_param_name:
        if background_tasks is None:
            background_tasks = BackgroundTasks()
        values[dependant.background_tasks_param_name] = background_tasks
    if dependant.response_param_name:
        values[dependant.response_param_name] = response

It is very simple and intuitive. It's designed to be easily extensible, and have modular components.

It has:

* Seriously impressive performance.
* WebSocket support.
* In-process background tasks.
* Startup and shutdown events.
* Test client built on HTTPX.
* CORS, GZip, Static Files, Streaming responses.
* Session and Cookie support.
* 100% test coverage.
* 100% type annotated codebase.

* Soporte para **WebSocket**.
* <abbr title="En español: tareas que se ejecutan en el fondo, sin frenar requests, en el mismo proceso. En ingles: In-process background tasks">Tareas en background</abbr>.
* Eventos de startup y shutdown.
* Cliente de pruebas construido con HTTPX.
* **CORS**, GZip, Static Files, Streaming responses.
* Soporte para **Session and Cookie**.

    with pytest.raises(OtherDependencyError):
        client.get("/context_b_raise")
    assert state["context_b"] == "finished b with a: started a"
    assert state["context_a"] == "finished a"


def test_background_tasks():
    response = client.get("/context_b_bg")
    data = response.json()
    assert data["context_b"] == "started b"
    assert data["context_a"] == "started a"
    assert data["bg"] == "not set"

```mermaid
sequenceDiagram

participant client as Client
participant handler as Exception handler
participant dep as Dep with yield
participant operation as Path Operation
participant tasks as Background tasks

    Note over client,tasks: Can raise exception for dependency, handled after response is sent
    Note over client,operation: Can raise HTTPException and can change the response
    client ->> dep: Start request

```mermaid
sequenceDiagram

participant client as Client
participant handler as Exception handler
participant dep as Dep with yield
participant operation as Path Operation
participant tasks as Background tasks

    Note over client,tasks: Can raise exception for dependency, handled after response is sent
    Note over client,operation: Can raise HTTPException and can change the response
    client ->> dep: Start request

```mermaid
sequenceDiagram

participant client as Client
participant handler as Exception handler
participant dep as Dep with yield
participant operation as Path Operation
participant tasks as Background tasks

    Note over client,tasks: Can raise exception for dependency, handled after response is sent
    Note over client,operation: Can raise HTTPException and can change the response
    client ->> dep: Start request