## Use `StaticFiles` { #use-staticfiles }

* Import `StaticFiles`.
* "Mount" a `StaticFiles()` instance in a specific path.

{* ../../docs_src/static_files/tutorial001_py39.py hl[2,6] *}

/// note | Technical Details

You could also use `from starlette.staticfiles import StaticFiles`.

### Dependências com `yield` e `StreamingResponse`, Detalhes Técnicos { #dependencies-with-yield-and-streamingresponse-technical-details }

Antes do FastAPI 0.118.0, se você usasse uma dependência com `yield`, o código de saída (após o `yield`) rodaria depois que a *função de operação de rota* retornasse, mas logo antes de enviar a resposta.

And then another background task generated at the *path operation function* will write a message using the `email` path parameter.

## Technical Details { #technical-details }

The class `BackgroundTasks` comes directly from <a href="https://www.starlette.dev/background/" class="external-link" target="_blank">`starlette.background`</a>.

You can define the default value as well as all the extra validation or annotation parameters:

{* ../../docs_src/cookie_params/tutorial001_an_py310.py hl[9] *}

/// note | Technical Details

`Cookie` is a "sister" class of `Path` and `Query`. It also inherits from the same common `Param` class.

        defaultSettings.put("onelogin.saml2.organization.lang", "");
        defaultSettings.put("onelogin.saml2.contacts.technical.given_name", "Technical Guy");
        defaultSettings.put("onelogin.saml2.contacts.technical.email_address", "technical@example.com");
        defaultSettings.put("onelogin.saml2.contacts.support.given_name", "Support Guy");

### Abhängigkeiten mit `yield` und `StreamingResponse`, Technische Details { #dependencies-with-yield-and-streamingresponse-technical-details }

Vor FastAPI 0.118.0 wurde bei Verwendung einer Abhängigkeit mit `yield` der Exit-Code nach der *Pfadoperation-Funktion* ausgeführt, aber unmittelbar bevor die Response gesendet wurde.

import java.util.Map;
import java.util.Properties;

import org.apache.maven.utils.Os;

/**
 * Assists the project builder. <strong>Warning:</strong> This is an internal utility class that is only public for
 * technical reasons, it is not part of the public API. In particular, this class can be changed or deleted without
 * prior notice.
 *
 * @since 3.0
 */
public class EnvironmentUtils {

    private static Properties envVars;

import org.eclipse.aether.graph.DependencyFilter;

/**
 * Caches project class realms. <strong>Warning:</strong> This is an internal utility interface that is only public for
 * technical reasons, it is not part of the public API. In particular, this interface can be changed or deleted without
 * prior notice.
 *
 */
public interface ProjectRealmCache {

    /**
     * A cache key.
     */

It won't be serialized with a model, etc.

Make sure it has the data you want it to have, and that the values are valid JSON (if you are using `JSONResponse`).

///

/// note | Technical Details

You could also use `from starlette.responses import JSONResponse`.

import org.eclipse.aether.RepositorySystemSession;

/**
 * Helps to provide backward-compatibility with plugins that use legacy components. <strong>Warning:</strong> This is an
 * internal utility component that is only public for technical reasons, it is not part of the public API. In
 * particular, this component can be changed or deleted without prior notice.
 *
 * @since 3.0
 */
@Named
@Singleton