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})

Por exemplo, vamos supor que você possua 4 endpoints na sua API (*operações de rota*):

* `/items/public/`
* `/items/private/`
* `/users/{user_id}/activate`
* `/items/pro/`

Você poderia adicionar diferentes requisitos de permissão para cada um deles utilizando apenas dependências e sub-dependências:

```mermaid
graph TB

from fastapi import FastAPI, Query
from typing_extensions import Annotated

app = FastAPI()


@app.get("/items/")
async def read_items(q: Annotated[str, Query(min_length=3)]):
    results = {"items": [{"item_id": "Foo"}, {"item_id": "Bar"}]}
    if q:
        results.update({"q": q})

Tarayıcımızda şu bağlantıyı açalım <a href="http://127.0.0.1:8000/items/5?q=somequery" class="external-link" target="_blank">http://127.0.0.1:8000/items/5?q=somequery</a>.

Aşağıdaki gibi bir JSON yanıtıyla karşılaşacağız:

```JSON
{"item_id": 5, "q": "somequery"}
```

Az önce oluşturduğumuz API:

* `/` ve `/items/{item_id}` <abbr title="Adres / Yol: Path ">_yollarına_</abbr> HTTP isteği alabilir.

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})

                    "properties": {
                        "detail": {
                            "title": "Detail",
                            "type": "array",
                            "items": {"$ref": "#/components/schemas/ValidationError"},
                        }
                    },
                },
                "Product": {
                    "title": "Product",

client = TestClient(app)

schema = {
    "components": {
        "schemas": {
            "HTTPValidationError": {
                "properties": {
                    "detail": {
                        "items": {"$ref": "#/components/schemas/ValidationError"},
                        "title": "Detail",
                        "type": "array",
                    }
                },
                "title": "HTTPValidationError",

    assert actual_schema == {
        "components": {
            "schemas": {
                "HTTPValidationError": {
                    "properties": {
                        "detail": {
                            "items": {"$ref": "#/components/schemas/ValidationError"},
                            "title": "Detail",
                            "type": "array",
                        }
                    },

from typing import Annotated

from fastapi import FastAPI, Query

app = FastAPI()


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

from typing import Union

from fastapi import FastAPI, Query

app = FastAPI()


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