That's what we'll solve, let's load the model before the requests are handled, but only right before the application starts receiving requests, not while  the code is being loaded.

## Lifespan

You can define this *startup* and *shutdown* logic using the `lifespan` parameter of the `FastAPI` app, and a "context manager" (I'll show you what that is in a second).

## Self-hosting JavaScript and CSS for docs

Self-hosting the JavaScript and CSS could be useful if, for example, you need your app to keep working even while offline, without open Internet access, or in a local network.

Here you'll see how to serve those files yourself, in the same FastAPI app, and configure the docs to use them.

### Project file structure

    tmp_path = tmp_path_factory.mktemp("data")
    cwd = os.getcwd()
    os.chdir(tmp_path)
    test_db = Path("./sql_app.db")
    if test_db.is_file():  # pragma: nocover
        test_db.unlink()
    # Import while creating the client to create the DB after starting the test session
    from docs_src.sql_databases.sql_app_py39 import alt_main

    # Ensure import side effects are re-executed
    importlib.reload(alt_main)

    tmp_path = tmp_path_factory.mktemp("data")
    cwd = os.getcwd()
    os.chdir(tmp_path)
    test_db = Path("./sql_app.db")
    if test_db.is_file():  # pragma: nocover
        test_db.unlink()
    # Import while creating the client to create the DB after starting the test session
    from docs_src.sql_databases.sql_app_py310 import main

    # Ensure import side effects are re-executed
    importlib.reload(main)

    tmp_path = tmp_path_factory.mktemp("data")
    cwd = os.getcwd()
    os.chdir(tmp_path)
    test_db = Path("./sql_app.db")
    if test_db.is_file():  # pragma: nocover
        test_db.unlink()
    # Import while creating the client to create the DB after starting the test session
    from docs_src.sql_databases.sql_app_py39 import main

    # Ensure import side effects are re-executed
    importlib.reload(main)

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

* By using a dependency you can simplify testing.
* You can use `.env` files with it.

</html>
"""


@app.get("/")
async def get():
    return HTMLResponse(html)


@app.websocket("/ws")
async def websocket_endpoint(websocket: WebSocket):
    await websocket.accept()
    while True:
        data = await websocket.receive_text()

async def websocket_endpoint(
    websocket: WebSocket,
    item_id: str,
    q: Union[int, None] = None,
    cookie_or_token: str = Depends(get_cookie_or_token),
):
    await websocket.accept()
    while True:
        data = await websocket.receive_text()
        await websocket.send_text(
            f"Session cookie or query token value is: {cookie_or_token}"
        )
        if q is not None:

async def websocket_endpoint(
    *,
    websocket: WebSocket,
    item_id: str,
    q: Union[int, None] = None,
    cookie_or_token: Annotated[str, Depends(get_cookie_or_token)],
):
    await websocket.accept()
    while True:
        data = await websocket.receive_text()
        await websocket.send_text(
            f"Session cookie or query token value is: {cookie_or_token}"
        )
        if q is not None: