request_validation_exception_handler,
    websocket_request_validation_exception_handler,
)
from fastapi.exceptions import RequestValidationError, WebSocketRequestValidationError
from fastapi.logger import logger
from fastapi.openapi.docs import (
    get_redoc_html,
    get_swagger_ui_html,
    get_swagger_ui_oauth2_redirect_html,
)
from fastapi.openapi.utils import get_openapi
from fastapi.params import Depends

from fastapi.concurrency import (
    asynccontextmanager,
    contextmanager_in_threadpool,
)
from fastapi.dependencies.models import Dependant, SecurityRequirement
from fastapi.logger import logger
from fastapi.security.base import SecurityBase
from fastapi.security.oauth2 import OAuth2, SecurityScopes
from fastapi.security.open_id_connect_url import OpenIdConnect

!!! warning
    The recommended way to handle the *startup* and *shutdown* is using the `lifespan` parameter of the `FastAPI` app as described above. If you provide a `lifespan` parameter, `startup` and `shutdown` event handlers will no longer be called. It's all `lifespan` or all events, not both.

    You can probably skip this part.

There's an alternative way to define this logic to be executed during *startup* and during *shutdown*.

```console
// Create an env var MY_NAME in line for this program call
$ MY_NAME="Wade Wilson" python main.py

// Now it can read the environment variable

Hello Wade Wilson from Python

// The env var no longer exists afterwards
$ python main.py

Hello World from Python
```

</div>

!!! tip

        return app.openapi_schema
    openapi_schema = get_openapi(
        title="Custom title",
        version="2.5.0",
        summary="This is a very custom OpenAPI schema",
        description="Here's a longer description of the custom **OpenAPI** schema",
        routes=app.routes,
    )
    openapi_schema["info"]["x-logo"] = {
        "url": "https://fastapi.tiangolo.com/img/logo-margin/logo-teal.png"
    }

    assert response.json() == {
        "openapi": "3.1.0",
        "info": {
            "title": "Custom title",
            "summary": "This is a very custom OpenAPI schema",
            "description": "Here's a longer description of the custom **OpenAPI** schema",
            "version": "2.5.0",
            "x-logo": {
                "url": "https://fastapi.tiangolo.com/img/logo-margin/logo-teal.png"
            },
        },

    async def app(websocket: WebSocket) -> None:
        async with AsyncExitStack() as async_exit_stack:
            # TODO: remove this scope later, after a few releases
            # This scope fastapi_astack is no longer used by FastAPI, kept for
            # compatibility, just in case
            websocket.scope["fastapi_astack"] = async_exit_stack
            solved_result = await solve_dependencies(
                request=websocket,