El valor del parámetro de path `item_id` se pasará a tu función como el argumento `item_id`.

Así que, si ejecutas este ejemplo y vas a [http://127.0.0.1:8000/items/foo](http://127.0.0.1:8000/items/foo), verás un response de:

```JSON
{"item_id":"foo"}
```

## Parámetros de path con tipos { #path-parameters-with-types }

The value of the path parameter `item_id` will be passed to your function as the argument `item_id`.

So, if you run this example and go to [http://127.0.0.1:8000/items/foo](http://127.0.0.1:8000/items/foo), you will see a response of:

```JSON
{"item_id":"foo"}
```

## Path parameters with types { #path-parameters-with-types }

sequenceDiagram
    participant App
    participant Client

    App->>App: Produce Item 1
    App->>Client: Send Item 1
    App->>App: Produce Item 2
    Client->>Client: Process Item 1
    App->>Client: Send Item 2
    App->>App: Produce Item 3
    Client->>Client: Process Item 2
    App->>Client: Send Item 3
    Client->>Client: Process Item 3
    Note over App: Keeps producing...
    Note over Client: Keeps consuming...
```

Se você não selecionar nenhum escopo, você terá "autenticado", mas quando você tentar acessar `/users/me/` ou `/users/me/items/`, você vai obter um erro dizendo que você não possui as permissões necessárias. Você ainda poderá acessar `/status/`.

E se você selecionar o escopo `me`, mas não o escopo `items`, você poderá acessar `/users/me/`, mas não `/users/me/items/`.

from fastapi import FastAPI, Query

app = FastAPI()


@app.get("/items/")
async def read_items(q: str | None = Query(default=None, max_length=50)):
    results = {"items": [{"item_id": "Foo"}, {"item_id": "Bar"}]}
    if q:
        results.update({"q": q})

    assert app.openapi()["paths"][path]["get"]["parameters"] == snapshot(
        [
            {
                "required": False,
                "schema": {
                    "anyOf": [
                        {"items": {"type": "string"}, "type": "array"},
                        {"type": "null"},
                    ],
                    "title": "P",
                },
                "name": "p",
                "in": "query",

from typing import Annotated

from fastapi import FastAPI, Query

app = FastAPI()


@app.get("/items/")
async def read_items(q: Annotated[str | None, Query(min_length=3)]):
    results = {"items": [{"item_id": "Foo"}, {"item_id": "Bar"}]}
    if q:
        results.update({"q": q})

from typing import Annotated

from fastapi import FastAPI, Query

app = FastAPI()


@app.get("/items/")
async def read_items(
    q: Annotated[str | None, Query(min_length=3, max_length=50)] = None,
):
    results = {"items": [{"item_id": "Foo"}, {"item_id": "Bar"}]}
    if q:
        results.update({"q": q})

from typing import Annotated

from fastapi import FastAPI, Query

app = FastAPI()


@app.get("/items/")
async def read_items(
    q: Annotated[
        str | None, Query(min_length=3, max_length=50, pattern="^fixedquery$")
    ] = None,
):
    results = {"items": [{"item_id": "Foo"}, {"item_id": "Bar"}]}
    if q:
        results.update({"q": q})

Если вы не выберете ни один scope, вы будете «аутентифицированы», но при попытке доступа к `/users/me/` или `/users/me/items/` получите ошибку о недостаточных разрешениях. При этом доступ к `/status/` будет возможен.

Если вы выберете scope `me`, но не `items`, вы сможете получить доступ к `/users/me/`, но не к `/users/me/items/`.