def app_shutdown() -> None:
        state.app_shutdown = True

    router = APIRouter()

    @router.on_event("startup")
    def router_startup() -> None:
        state.router_startup = True

    @router.on_event("shutdown")
    def router_shutdown() -> None:
        state.router_shutdown = True

    sub_router = APIRouter()

    @sub_router.on_event("startup")
    def sub_router_startup() -> None:

    text: str
    completed: bool


class Note(BaseModel):
    id: int
    text: str
    completed: bool


app = FastAPI()


@app.on_event("startup")
async def startup():
    await database.connect()


@app.on_event("shutdown")
async def shutdown():
    await database.disconnect()


@app.get("/notes/", response_model=List[Note])
async def read_notes():
    query = notes.select()

from fastapi import FastAPI

app = FastAPI()

items = {}


@app.on_event("startup")
async def startup_event():
    items["foo"] = {"name": "Fighters"}
    items["bar"] = {"name": "Tenders"}


@app.get("/items/{item_id}")
async def read_items(item_id: str):

            - include_router
            - get
            - put
            - post
            - delete
            - options
            - head
            - patch
            - trace

            - include_router
            - get
            - put
            - post
            - delete
            - options
            - head
            - patch
            - trace

            - include_router
            - get
            - put
            - post
            - delete
            - options
            - head
            - patch
            - trace
            - on_event
            - middleware

            - include_router
            - get
            - put
            - post
            - delete
            - options
            - head
            - patch
            - trace
            - on_event
            - middleware

from fastapi import FastAPI
from fastapi.testclient import TestClient

app = FastAPI()

items = {}


@app.on_event("startup")
async def startup_event():
    items["foo"] = {"name": "Fighters"}
    items["bar"] = {"name": "Tenders"}


@app.get("/items/{item_id}")
async def read_items(item_id: str):
    return items[item_id]


def test_read_items():
    with TestClient(app) as client:

from fastapi import FastAPI

app = FastAPI()


@app.on_event("shutdown")
def shutdown_event():
    with open("log.txt", mode="a") as log:
        log.write("Application shutdown")


@app.get("/items/")
async def read_items():

href="https://stackoverflow.com/questions/41584243/runtimeerror-task-attached-to-a-different-loop" class="external-link" target="_blank">MongoDB's MotorClient</a>) Remember to instantiate objects that need an event loop only within async functions, e.g. an `'@app.on_event("startup")` callback....