router = APIRouter()

    @app.post("/", response_model=List[Item], responses={404: {"model": List[Message]}})
    def post_root(item1: Item, item2: Item):
        return item1, item2  # pragma: nocover

    @router.post(
        "/router", response_model=List[Item], responses={404: {"model": List[Message]}}
    )
    def post_router(item1: Item, item2: Item):

    responses={404: {"description": "Not found"}},
)


fake_items_db = {"plumbus": {"name": "Plumbus"}, "gun": {"name": "Portal Gun"}}


@router.get("/")
async def read_items():
    return fake_items_db


@router.get("/{item_id}")
async def read_item(item_id: str):
    if item_id not in fake_items_db:
        raise HTTPException(status_code=404, detail="Item not found")

class Message(BaseModel):
    message: str


app = FastAPI()


@app.get("/items/{item_id}", response_model=Item, responses={404: {"model": Message}})
async def read_item(item_id: str):
    if item_id == "foo":
        return {"id": "foo", "value": "there goes my hero"}

    responses={404: {"description": "Not found"}},
)


fake_items_db = {"plumbus": {"name": "Plumbus"}, "gun": {"name": "Portal Gun"}}


@router.get("/")
async def read_items():
    return fake_items_db


@router.get("/{item_id}")
async def read_item(item_id: str):
    if item_id not in fake_items_db:
        raise HTTPException(status_code=404, detail="Item not found")

Они похожи на двухсотые HTTP статус-коды (от 200 до 299), которые означают, что запрос обработан успешно.

Четырёхсотые статус-коды означают, что ошибка произошла по вине клиента.

Помните ли ошибки **"404 Not Found "** (и шутки) ?

## Использование `HTTPException`

Для возврата клиенту HTTP-ответов с ошибками используется `HTTPException`.

### Импортируйте `HTTPException`

```Python hl_lines="1"

    responses={404: {"description": "Not found"}},
)


fake_items_db = {"plumbus": {"name": "Plumbus"}, "gun": {"name": "Portal Gun"}}


@router.get("/")
async def read_items():
    return fake_items_db


@router.get("/{item_id}")
async def read_item(item_id: str):
    if item_id not in fake_items_db:
        raise HTTPException(status_code=404, detail="Item not found")

@app.get("/items/{item_id}")
def get_item(item_id: str, username: str = Depends(get_username)):
    if item_id not in data:
        raise HTTPException(status_code=404, detail="Item not found")
    item = data[item_id]
    if item["owner"] != username:
        raise OwnerError(username)

@app.get("/items/{item_id}")
def get_item(item_id: str, username: Annotated[str, Depends(get_username)]):
    if item_id not in data:
        raise HTTPException(status_code=404, detail="Item not found")
    item = data[item_id]
    if item["owner"] != username:
        raise OwnerError(username)

    response = client.post("/users/rick")
    assert response.status_code == 405, response.text


def test_invalid_path_doesnt_match():
    response = client.post("/usersx/rick")
    assert response.status_code == 404, response.text


def test_websocket():
    with client.websocket_connect("/items/portal-gun") as websocket:
        data = websocket.receive_json()

@app.get("/users/{user_id}", response_model=schemas.User)
def read_user(user_id: int, db: Session = Depends(get_db)):
    db_user = crud.get_user(db, user_id=user_id)
    if db_user is None:
        raise HTTPException(status_code=404, detail="User not found")
    return db_user


@app.post("/users/{user_id}/items/", response_model=schemas.Item)
def create_item_for_user(
    user_id: int, item: schemas.ItemCreate, db: Session = Depends(get_db)
):