/// info | Información Técnica

`Security` es en realidad una subclase de `Depends`, y tiene solo un parámetro extra que veremos más adelante.

Pero al usar `Security` en lugar de `Depends`, **FastAPI** sabrá que puede declarar scopes de seguridad, usarlos internamente y documentar la API con OpenAPI.

Pero cuando importas `Query`, `Path`, `Depends`, `Security` y otros de `fastapi`, en realidad son funciones que devuelven clases especiales.

/// info | Informações Técnicas

`Security` é na verdade uma subclasse de `Depends`, e ele possui apenas um parâmetro extra que veremos depois.

Porém ao utilizar `Security` no lugar de `Depends`, o **FastAPI** saberá que ele pode declarar escopos de segurança, utilizá-los internamente, e documentar a API com o OpenAPI.

Para entender más sobre esto, ve la sección <a href="https://fastapi.tiangolo.com/benchmarks/" class="internal-link" target="_blank">Benchmarks</a>.

## Dependencias

FastAPI depende de Pydantic y Starlette.

### Dependencias `standard`

Cuando instalas FastAPI con `pip install "fastapi[standard]"` viene con el grupo `standard` de dependencias opcionales:

Usadas por Pydantic:

Para entender mais sobre performance, veja a seção <a href="https://fastapi.tiangolo.com/pt/benchmarks/" class="internal-link" target="_blank">Comparações</a>.

## Dependências

O FastAPI depende do Pydantic e do Starlette.


### Dependências `standard`

Quando você instala o FastAPI com `pip install "fastapi[standard]"`, ele vêm com o grupo `standard` (padrão) de dependências opcionais:

> **This list is non exhaustive, it depends on the operating system and filesystem under use - please consult your operating system vendor for a more comprehensive list of special characters**.

MinIO recommends using Linux operating system for production workloads.

At some point, you will probably end up writing many different programs that depend on **different packages**. And some of these projects you work on will depend on **different versions** of the same package. 😱

For example, you could create a project called `philosophers-stone`, this program depends on another package called **`harry`, using the version `1`**. So, you need to install `harry`.

```mermaid

```

////

//// tab | Python 3.8 non-Annotated

/// tip

Prefer to use the `Annotated` version if possible.

///

```Python
commons: CommonQueryParams = Depends()
```

////

You declare the dependency as the type of the parameter, and you use `Depends()` without any parameter, instead of having to write the full class *again* inside of `Depends(CommonQueryParams)`.

        assertNotNull(result);
        assertTrue(result instanceof DefaultQueryBuilder);

        // Verify query was processed
        // Note: Field logging behavior depends on implementation
    }

    public void test_convertPhraseQuery_singleTerm_defaultField_dismax() {
        // Test with single term in default field with boost > 1

Although you use `Depends` in the parameters of your function the same way you use `Body`, `Query`, etc, `Depends` works a bit differently.

You only give `Depends` a single parameter.

This parameter must be something like a function.

You **don't call it** directly (don't add the parenthesis at the end), you just pass it as a parameter to `Depends()`.

And that function takes parameters in the same way that *path operation functions* do.

Let's focus on the parameters declared:

* Even though this function is a dependency ("dependable") itself, it also declares another dependency (it "depends" on something else).
    * It depends on the `query_extractor`, and assigns the value returned by it to the parameter `q`.
* It also declares an optional `last_query` cookie, as a `str`.