"paid": true
}
```

y esperaría un response de esa *API externa* con un JSON body como:

```JSON
{
    "ok": true
}
```

/// tip | Consejo

Observa cómo la URL del callback utilizada contiene la URL recibida como parámetro de query en `callback_url` (`https://www.external.org/events`) y también el `id` de la factura desde dentro del JSON body (`2expen51ve`).

///

# Static Files - `StaticFiles`

You can use the `StaticFiles` class to serve static files, like JavaScript, CSS, images, etc.

Read more about it in the [FastAPI docs for Static Files](https://fastapi.tiangolo.com/tutorial/static-files/).

You can import it directly from `fastapi.staticfiles`:

```python
from fastapi.staticfiles import StaticFiles
```

<img src="/img/tutorial/security/image07.png">

Autoriza la aplicación de la misma manera que antes.

Usando las credenciales:

Usuario: `johndoe`
Contraseña: `secret`

/// check | Revisa

Observa que en ninguna parte del código está la contraseña en texto claro "`secret`", solo tenemos la versión con hash.

///

<img src="/img/tutorial/security/image08.png">

 *
 */
@Deprecated
public interface ClasspathTransformation {
    String ROLE = ClasspathTransformation.class.getName();

    /**
     * Transform Graph into a Collection of metadata objects that
     * could serve as a classpath for a particular scope
     *
     * @param dirtyGraph - dependency graph
     * @param scope - which classpath to extract
     * @param resolve - whether to resolve artifacts.

* `@app.get()`
* `@app.post()`
* `@app.put()`
* `@app.delete()`
* etc.

{* ../../docs_src/response_status_code/tutorial001_py39.py hl[6] *}

/// note | Nota

Observa que `status_code` es un parámetro del método "decorador" (`get`, `post`, etc). No de tu *path operation function*, como todos los parámetros y body.

///

El parámetro `status_code` recibe un número con el código de estado HTTP.

# Static Files { #static-files }

You can serve static files automatically from a directory using `StaticFiles`.

## 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`.

      }
    }
  }

  companion object {
    val playProviderFactory: DeferredSocketAdapter.Factory =
      factory("com.google.android.gms.org.conscrypt")

    /**
     * Builds a SocketAdapter from an observed implementation class, by grabbing the Class
     * reference to perform reflection on at runtime.
     *
     * @param actualSSLSocketClass the runtime class of Conscrypt class socket.
     */

	if errCode != ErrNone {
		writeErrorResponse(ctx, w, errorCodes.ToAPIErr(errCode), r.URL)
		return
	}

	// Validate the query params before beginning to serve the request.
	if s3Error := validateListObjectsArgs(prefix, marker, delimiter, encodingType, maxkeys); s3Error != ErrNone {
		writeErrorResponse(ctx, w, errorCodes.ToAPIErr(s3Error), r.URL)
		return
	}

## Benchmarks e velocidade { #benchmarks-and-speed }

Ao verificar os _benchmarks_, é comum observar algumas ferramentas de diferentes tipos comparadas como equivalentes.

Especificamente, observa-se Uvicorn, Starlette e FastAPI comparados juntos (entre muitas outras ferramentas).

    private var etag: String? = null

    /** Age of the cached response. */
    private var ageSeconds = -1

    /**
     * Returns true if computeFreshnessLifetime used a heuristic. If we used a heuristic to serve a
     * cached response older than 24 hours, we are required to attach a warning.
     */
    private fun isFreshnessLifetimeHeuristic(): Boolean = cacheResponse!!.cacheControl.maxAgeSeconds == -1 && expires == null