Pretty printing all JSON output in Silex PHP

If you’re doing some REST-ish API with Silex, or at least you need to output JSON. You’re probably doing something like this :

$app = new Silex\Application();

$app->match('/hello', function() use($app) {
    // code

    return $app->json($response, 200);


But, you surely want something well-presented like with the JSON_PRETTY_PRINT flag you pass to the json_encode function when you do it in flat PHP.

Don’t worry, here’s the tip using after middleware (if you don’t already know them) :

use Symfony\Component\HttpFoundation\JsonResponse;

// ...

$app->after(function(Request $request, Response $response) {
    if($response instanceof JsonResponse) {

    return $response;

You just have to write this before running your app.