/// info

`users.router` contains the `APIRouter` inside of the file `app/routers/users.py`.

And `items.router` contains the `APIRouter` inside of the file `app/routers/items.py`.

///

With `app.include_router()` we can add each `APIRouter` to the main `FastAPI` application.

It will include all the routes from that router as part of it.

/// note | "Technical Details"

@app.get("/")
async def not_timed():
    return {"message": "Not timed"}


@router.get("/timed")
async def timed():
    return {"message": "It's the time of my life"}

/// info | "Informação"

`users.router` contém o `APIRouter` dentro do arquivo `app/routers/users.py`.

E `items.router` contém o `APIRouter` dentro do arquivo `app/routers/items.py`.

///

Com `app.include_router()` podemos adicionar cada `APIRouter` ao aplicativo principal `FastAPI`.

Ele incluirá todas as rotas daquele roteador como parte dele.

/// note | "Detalhe Técnico"

        await self.app(scope, wrapper, send)


@router.post("/middleware")
def run_middleware(file: UploadFile = File(..., description="Big File")):
    return {"message": "OK"}


app.include_router(router)
app.add_middleware(ContentSizeLimitMiddleware, max_content_size=2**8)


client = TestClient(app)


def test_custom_middleware_exception(tmp_path: Path):
    default_pydantic_max_size = 2**16

from fastapi.testclient import TestClient

app = FastAPI()

router = APIRouter()


@router.get("/users/{id}")
def read_user(segment: str, id: str):
    return {"segment": segment, "id": id}


app.include_router(router, prefix="/{segment}")


client = TestClient(app)


def test_get():
    response = client.get("/seg/users/foo")
    assert response.status_code == 200, response.text

The original dependency could be used in a *path operation function*, a *path operation decorator* (when you don't use the return value), a `.include_router()` call, etc.

FastAPI will still be able to override it.

///

Then you can reset your overrides (remove them) by setting `app.dependency_overrides` to be an empty `dict`:

```Python

    app = FastAPI()

    router = APIRouter(prefix="/nested")

    @router.get("/test")
    async def test(var: Annotated[str, Query()] = "bar"):
        return {"foo": var}

    app.include_router(router)

    client = TestClient(app)

    response = client.get("/nested/test")
    assert response.status_code == 200
    assert response.json() == {"foo": "bar"}


def test_openapi_schema():

```Python hl_lines="28-29  32"
{!../../docs_src/dependency_testing/tutorial001.py!}
```

/// tip

👆 💪 ⚒ 🔗 🔐 🔗 ⚙️ 🙆 👆 **FastAPI** 🈸.

⏮️ 🔗 💪 ⚙️ *➡ 🛠️ 🔢*, *➡ 🛠️ 👨‍🎨* (🕐❔ 👆 🚫 ⚙️ 📨 💲), `.include_router()` 🤙, ♒️.

FastAPI 🔜 💪 🔐 ⚫️.

///

⤴️ 👆 💪 ⏲ 👆 🔐 (❎ 👫) ⚒ `app.dependency_overrides` 🛁 `dict`:

```Python
app.dependency_overrides = {}
```

/// tip

            (e.g. "payment successful").
    """
    # Send the invoice, collect the money, send the notification (the callback)
    return {"msg": "Invoice received"}


app.include_router(subrouter, callbacks=events_callback_router.routes)

client = TestClient(app)


def test_get():
    response = client.post(
        "/invoices/", json={"id": "fooinvoice", "customer": "John", "total": 5.3}

    responses={
        "400": {"description": "Error with str"},
        "5XX": {"model": ResponseModel},
        "default": {"model": ResponseModel},
    },
)
async def d():
    return "d"


app.include_router(router)


client = TestClient(app)


def test_a():
    response = client.get("/a")
    assert response.status_code == 200, response.text
    assert response.json() == "a"


def test_b():