diff --git a/src/Event/NullEventDispatcher.php b/src/Event/NullEventDispatcher.php
new file mode 100644
index 0000000..23768a4
--- /dev/null
+++ b/src/Event/NullEventDispatcher.php
@@ -0,0 +1,15 @@
+<?php
+
+declare(strict_types=1);
+
+namespace SpomkyLabs\PwaBundle\Event;
+
+use Psr\EventDispatcher\EventDispatcherInterface;
+
+final readonly class NullEventDispatcher implements EventDispatcherInterface
+{
+    public function dispatch(object $event): object
+    {
+        return $event;
+    }
+}
diff --git a/src/Event/PostManifestCompileEvent.php b/src/Event/PostManifestCompileEvent.php
new file mode 100644
index 0000000..53db27e
--- /dev/null
+++ b/src/Event/PostManifestCompileEvent.php
@@ -0,0 +1,16 @@
+<?php
+
+declare(strict_types=1);
+
+namespace SpomkyLabs\PwaBundle\Event;
+
+use SpomkyLabs\PwaBundle\Dto\Manifest;
+
+final class PostManifestCompileEvent
+{
+    public function __construct(
+        public Manifest $manifest,
+        public string $data
+    ) {
+    }
+}
diff --git a/src/Event/PreManifestCompileEvent.php b/src/Event/PreManifestCompileEvent.php
new file mode 100644
index 0000000..3fcbcaf
--- /dev/null
+++ b/src/Event/PreManifestCompileEvent.php
@@ -0,0 +1,15 @@
+<?php
+
+declare(strict_types=1);
+
+namespace SpomkyLabs\PwaBundle\Event;
+
+use SpomkyLabs\PwaBundle\Dto\Manifest;
+
+class PreManifestCompileEvent
+{
+    public function __construct(
+        public Manifest $manifest,
+    ) {
+    }
+}
diff --git a/src/Subscriber/ManifestCompileEventListener.php b/src/Subscriber/ManifestCompileEventListener.php
index dae83e6..65b89c9 100644
--- a/src/Subscriber/ManifestCompileEventListener.php
+++ b/src/Subscriber/ManifestCompileEventListener.php
@@ -4,7 +4,11 @@
 
 namespace SpomkyLabs\PwaBundle\Subscriber;
 
+use Psr\EventDispatcher\EventDispatcherInterface;
 use SpomkyLabs\PwaBundle\Dto\Manifest;
+use SpomkyLabs\PwaBundle\Event\NullEventDispatcher;
+use SpomkyLabs\PwaBundle\Event\PostManifestCompileEvent;
+use SpomkyLabs\PwaBundle\Event\PreManifestCompileEvent;
 use Symfony\Component\AssetMapper\Event\PreAssetsCompileEvent;
 use Symfony\Component\AssetMapper\Path\PublicAssetsFilesystemInterface;
 use Symfony\Component\DependencyInjection\Attribute\Autowire;
@@ -21,6 +25,8 @@
 #[AsEventListener(PreAssetsCompileEvent::class)]
 final readonly class ManifestCompileEventListener
 {
+    private EventDispatcherInterface $dispatcher;
+
     private string $manifestPublicUrl;
 
     private array $jsonOptions;
@@ -36,7 +42,9 @@ public function __construct(
         private PublicAssetsFilesystemInterface $assetsFilesystem,
         #[Autowire('%kernel.debug%')]
         bool $debug,
+        null|EventDispatcherInterface $dispatcher = null,
     ) {
+        $this->dispatcher = $dispatcher ?? new NullEventDispatcher();
         $this->manifestPublicUrl = '/' . trim($manifestPublicUrl, '/');
         $options = [
             AbstractObjectNormalizer::SKIP_UNINITIALIZED_VALUES => true,
@@ -55,7 +63,11 @@ public function __invoke(PreAssetsCompileEvent $event): void
         if (! $this->manifestEnabled) {
             return;
         }
-        $data = $this->serializer->serialize($this->manifest, 'json', $this->jsonOptions);
-        $this->assetsFilesystem->write($this->manifestPublicUrl, $data);
+        $manifest = clone $this->manifest;
+        $this->dispatcher->dispatch(new PreManifestCompileEvent($manifest));
+        $data = $this->serializer->serialize($manifest, 'json', $this->jsonOptions);
+        $postEvent = new PostManifestCompileEvent($manifest, $data);
+        $this->dispatcher->dispatch($postEvent);
+        $this->assetsFilesystem->write($this->manifestPublicUrl, $postEvent->data);
     }
 }
diff --git a/src/Subscriber/PwaDevServerSubscriber.php b/src/Subscriber/PwaDevServerSubscriber.php
index 74e7294..0083454 100644
--- a/src/Subscriber/PwaDevServerSubscriber.php
+++ b/src/Subscriber/PwaDevServerSubscriber.php
@@ -4,8 +4,12 @@
 
 namespace SpomkyLabs\PwaBundle\Subscriber;
 
+use Psr\EventDispatcher\EventDispatcherInterface;
 use SpomkyLabs\PwaBundle\Dto\Manifest;
 use SpomkyLabs\PwaBundle\Dto\ServiceWorker;
+use SpomkyLabs\PwaBundle\Event\NullEventDispatcher;
+use SpomkyLabs\PwaBundle\Event\PostManifestCompileEvent;
+use SpomkyLabs\PwaBundle\Event\PreManifestCompileEvent;
 use SpomkyLabs\PwaBundle\Service\ServiceWorkerCompiler;
 use Symfony\Component\Config\FileLocator;
 use Symfony\Component\DependencyInjection\Attribute\Autowire;
@@ -31,6 +35,8 @@
 
 final readonly class PwaDevServerSubscriber implements EventSubscriberInterface
 {
+    private EventDispatcherInterface $dispatcher;
+
     private string $manifestPublicUrl;
 
     private null|string $serviceWorkerPublicUrl;
@@ -55,7 +61,9 @@ public function __construct(
         private null|Profiler $profiler,
         #[Autowire('%kernel.debug%')]
         bool $debug,
+        null|EventDispatcherInterface $dispatcher = null,
     ) {
+        $this->dispatcher = $dispatcher ?? new NullEventDispatcher();
         $this->manifestPublicUrl = '/' . trim($manifestPublicUrl, '/');
         $serviceWorkerPublicUrl = $serviceWorker->dest;
         $this->serviceWorkerPublicUrl = '/' . trim($serviceWorkerPublicUrl, '/');
@@ -128,12 +136,17 @@ public static function getSubscribedEvents(): array
     private function serveManifest(RequestEvent $event): void
     {
         $this->profiler?->disable();
-        $body = $this->serializer->serialize($this->manifest, 'json', $this->jsonOptions);
-        $response = new Response($body, Response::HTTP_OK, [
+        $manifest = clone $this->manifest;
+        $this->dispatcher->dispatch(new PreManifestCompileEvent($manifest));
+        $data = $this->serializer->serialize($manifest, 'json', $this->jsonOptions);
+        $postEvent = new PostManifestCompileEvent($manifest, $data);
+        $this->dispatcher->dispatch($postEvent);
+
+        $response = new Response($data, Response::HTTP_OK, [
             'Cache-Control' => 'public, max-age=604800, immutable',
             'Content-Type' => 'application/manifest+json',
             'X-Manifest-Dev' => true,
-            'Etag' => hash('xxh128', $body),
+            'Etag' => hash('xxh128', $data),
         ]);
 
         $event->setResponse($response);