ETag & conditional requests

Use CacheValidatorsMiddleware early in the pipeline. It can short-circuit If-None-Match and If-Modified-Since before your handler does more work.

use Infocyph\Webrick\Middleware\CacheValidatorsMiddleware;
use Infocyph\Webrick\Request\Request;
use Infocyph\Webrick\Response\Response;
use Infocyph\Webrick\Router\Facade\Router as Route;

$preGlobal[] = new CacheValidatorsMiddleware(
    static function (Request $request): array {
        unset($request);

        $payload = json_encode(['version' => 1, 'shape' => 'stable'], JSON_UNESCAPED_SLASHES);
        $etag = '"' . hash('sha256', $payload) . '"';
        $lastModified = gmdate('D, d M Y H:i:s') . ' GMT';

        return [$etag, $lastModified];
    },
);

Route::get('/profile', fn() => Response::json(['user' => 'alice'])
    ->withHeader('Cache-Control', 'public, max-age=60'), 'profile');