diff --git a/src/Symfony/Component/Notifier/Bridge/Mercure/CHANGELOG.md b/src/Symfony/Component/Notifier/Bridge/Mercure/CHANGELOG.md
index 1f2b652ac20ea..29eb84188aded 100644
--- a/src/Symfony/Component/Notifier/Bridge/Mercure/CHANGELOG.md
+++ b/src/Symfony/Component/Notifier/Bridge/Mercure/CHANGELOG.md
@@ -1,6 +1,11 @@
 CHANGELOG
 =========
 
+7.3
+---
+
+ * Add `content` option
+
 5.3
 ---
 
diff --git a/src/Symfony/Component/Notifier/Bridge/Mercure/MercureOptions.php b/src/Symfony/Component/Notifier/Bridge/Mercure/MercureOptions.php
index da3b2e8797b34..cd55a68efde71 100644
--- a/src/Symfony/Component/Notifier/Bridge/Mercure/MercureOptions.php
+++ b/src/Symfony/Component/Notifier/Bridge/Mercure/MercureOptions.php
@@ -23,17 +23,19 @@ final class MercureOptions implements MessageOptionsInterface
     private ?string $id;
     private ?string $type;
     private ?int $retry;
+    private ?array $content;
 
     /**
      * @param string|string[]|null $topics
      */
-    public function __construct(string|array|null $topics = null, bool $private = false, ?string $id = null, ?string $type = null, ?int $retry = null)
+    public function __construct(string|array|null $topics = null, bool $private = false, ?string $id = null, ?string $type = null, ?int $retry = null, ?array $content = null)
     {
         $this->topics = null !== $topics ? (array) $topics : null;
         $this->private = $private;
         $this->id = $id;
         $this->type = $type;
         $this->retry = $retry;
+        $this->content = $content;
     }
 
     /**
@@ -64,6 +66,11 @@ public function getRetry(): ?int
         return $this->retry;
     }
 
+    public function getContent(): ?array
+    {
+        return $this->content;
+    }
+
     public function toArray(): array
     {
         return [
@@ -72,6 +79,7 @@ public function toArray(): array
             'id' => $this->id,
             'type' => $this->type,
             'retry' => $this->retry,
+            'content' => $this->content,
         ];
     }
 
diff --git a/src/Symfony/Component/Notifier/Bridge/Mercure/MercureTransport.php b/src/Symfony/Component/Notifier/Bridge/Mercure/MercureTransport.php
index 72559b85fa85f..355af24982fff 100644
--- a/src/Symfony/Component/Notifier/Bridge/Mercure/MercureTransport.php
+++ b/src/Symfony/Component/Notifier/Bridge/Mercure/MercureTransport.php
@@ -77,6 +77,8 @@ protected function doSend(MessageInterface $message): SentMessage
             '@context' => 'https://www.w3.org/ns/activitystreams',
             'type' => 'Announce',
             'summary' => $message->getSubject(),
+            'mediaType' => 'application/json',
+            'content' => $options->getContent(),
         ]), $options->isPrivate(), $options->getId(), $options->getType(), $options->getRetry());
 
         try {
diff --git a/src/Symfony/Component/Notifier/Bridge/Mercure/Tests/MercureOptionsTest.php b/src/Symfony/Component/Notifier/Bridge/Mercure/Tests/MercureOptionsTest.php
index 7503f9e40456f..d3a7ed8aa6a95 100644
--- a/src/Symfony/Component/Notifier/Bridge/Mercure/Tests/MercureOptionsTest.php
+++ b/src/Symfony/Component/Notifier/Bridge/Mercure/Tests/MercureOptionsTest.php
@@ -24,12 +24,13 @@ public function testConstructWithDefaults()
             'id' => null,
             'type' => null,
             'retry' => null,
+            'content' => null
         ]);
     }
 
     public function testConstructWithParameters()
     {
-        $options = (new MercureOptions('/topic/1', true, 'id', 'type', 1));
+        $options = (new MercureOptions('/topic/1', true, 'id', 'type', 1, ['tag' => '1234', 'body' => 'TEST']));
 
         $this->assertSame($options->toArray(), [
             'topics' => ['/topic/1'],
@@ -37,6 +38,7 @@ public function testConstructWithParameters()
             'id' => 'id',
             'type' => 'type',
             'retry' => 1,
+            'content' => ['tag' => '1234', 'body' => 'TEST'],
         ]);
     }
 
diff --git a/src/Symfony/Component/Notifier/Bridge/Mercure/Tests/MercureTransportTest.php b/src/Symfony/Component/Notifier/Bridge/Mercure/Tests/MercureTransportTest.php
index bfe9190a8e592..6e7c391b7278d 100644
--- a/src/Symfony/Component/Notifier/Bridge/Mercure/Tests/MercureTransportTest.php
+++ b/src/Symfony/Component/Notifier/Bridge/Mercure/Tests/MercureTransportTest.php
@@ -114,7 +114,7 @@ public function testSendWithMercureOptions()
     {
         $hub = new MockHub('https://foo.com/.well-known/mercure', new StaticTokenProvider('foo'), function (Update $update): string {
             $this->assertSame(['/topic/1', '/topic/2'], $update->getTopics());
-            $this->assertSame('{"@context":"https:\/\/www.w3.org\/ns\/activitystreams","type":"Announce","summary":"subject"}', $update->getData());
+            $this->assertSame('{"@context":"https:\/\/www.w3.org\/ns\/activitystreams","type":"Announce","summary":"subject","mediaType":"application\/json","content":null}', $update->getData());
             $this->assertSame('id', $update->getId());
             $this->assertSame('type', $update->getType());
             $this->assertSame(1, $update->getRetry());
@@ -130,7 +130,7 @@ public function testSendWithMercureOptionsButWithoutOptionTopic()
     {
         $hub = new MockHub('https://foo.com/.well-known/mercure', new StaticTokenProvider('foo'), function (Update $update): string {
             $this->assertSame(['https://symfony.com/notifier'], $update->getTopics());
-            $this->assertSame('{"@context":"https:\/\/www.w3.org\/ns\/activitystreams","type":"Announce","summary":"subject"}', $update->getData());
+            $this->assertSame('{"@context":"https:\/\/www.w3.org\/ns\/activitystreams","type":"Announce","summary":"subject","mediaType":"application\/json","content":null}', $update->getData());
             $this->assertSame('id', $update->getId());
             $this->assertSame('type', $update->getType());
             $this->assertSame(1, $update->getRetry());
@@ -146,7 +146,7 @@ public function testSendWithoutMercureOptions()
     {
         $hub = new MockHub('https://foo.com/.well-known/mercure', new StaticTokenProvider('foo'), function (Update $update): string {
             $this->assertSame(['https://symfony.com/notifier'], $update->getTopics());
-            $this->assertSame('{"@context":"https:\/\/www.w3.org\/ns\/activitystreams","type":"Announce","summary":"subject"}', $update->getData());
+            $this->assertSame('{"@context":"https:\/\/www.w3.org\/ns\/activitystreams","type":"Announce","summary":"subject","mediaType":"application\/json","content":null}', $update->getData());
             $this->assertFalse($update->isPrivate());
 
             return 'id';