diff --git a/examples/misc/parallel-chat-gpt.php b/examples/misc/parallel-chat-gpt.php
index 5357f82db..de26d384f 100644
--- a/examples/misc/parallel-chat-gpt.php
+++ b/examples/misc/parallel-chat-gpt.php
@@ -25,7 +25,7 @@
 $results = [];
 foreach (range('A', 'D') as $letter) {
     echo ' - Request for the letter '.$letter.' initiated.'.\PHP_EOL;
-    $results[] = $platform->invoke('gpt-4o-mini', $messages->with(Message::ofUser($letter)));
+    $results[] = $platform->invoke('gpt-4o-mini', (clone $messages)->add(Message::ofUser($letter)));
 }
 
 echo 'Waiting for the responses ...'.\PHP_EOL;
diff --git a/src/platform/src/Message/MessageBag.php b/src/platform/src/Message/MessageBag.php
index c480f107f..fe9e4978a 100644
--- a/src/platform/src/Message/MessageBag.php
+++ b/src/platform/src/Message/MessageBag.php
@@ -12,14 +12,21 @@
 namespace Symfony\AI\Platform\Message;
 
 use Symfony\AI\Platform\Metadata\MetadataAwareTrait;
+use Symfony\Component\Uid\AbstractUid;
+use Symfony\Component\Uid\TimeBasedUidInterface;
+use Symfony\Component\Uid\Uuid;
 
 /**
  * @author Christopher Hertel <mail@christopher-hertel.de>
+ *
+ * @implements \IteratorAggregate<MessageInterface>
  */
-class MessageBag implements \Countable
+class MessageBag implements \IteratorAggregate, \Countable
 {
     use MetadataAwareTrait;
 
+    private AbstractUid&TimeBasedUidInterface $id;
+
     /**
      * @var list<MessageInterface>
      */
@@ -28,11 +35,31 @@ class MessageBag implements \Countable
     public function __construct(MessageInterface ...$messages)
     {
         $this->messages = array_values($messages);
+        $this->id = Uuid::v7();
+    }
+
+    public function __clone()
+    {
+        $this->id = Uuid::v7();
+    }
+
+    public function getId(): AbstractUid&TimeBasedUidInterface
+    {
+        return $this->id;
     }
 
-    public function add(MessageInterface $message): void
+    public function add(MessageInterface $message): self
     {
         $this->messages[] = $message;
+
+        return $this;
+    }
+
+    public function prepend(MessageInterface $message): self
+    {
+        $this->messages = array_merge([$message], $this->messages);
+
+        return $this;
     }
 
     /**
@@ -65,20 +92,11 @@ public function getUserMessage(): ?UserMessage
         return null;
     }
 
-    public function with(MessageInterface $message): self
-    {
-        $messages = clone $this;
-        $messages->add($message);
-
-        return $messages;
-    }
-
     public function merge(self $messageBag): self
     {
-        $messages = clone $this;
-        $messages->messages = array_merge($messages->messages, $messageBag->getMessages());
+        $this->messages = array_merge($this->messages, $messageBag->getMessages());
 
-        return $messages;
+        return $this;
     }
 
     public function withoutSystemMessage(): self
@@ -92,14 +110,6 @@ public function withoutSystemMessage(): self
         return $messages;
     }
 
-    public function prepend(MessageInterface $message): self
-    {
-        $messages = clone $this;
-        $messages->messages = array_merge([$message], $messages->messages);
-
-        return $messages;
-    }
-
     public function containsAudio(): bool
     {
         foreach ($this->messages as $message) {
@@ -126,4 +136,9 @@ public function count(): int
     {
         return \count($this->messages);
     }
+
+    public function getIterator(): \Traversable
+    {
+        return new \ArrayIterator($this->messages);
+    }
 }
diff --git a/src/platform/tests/Message/MessageBagTest.php b/src/platform/tests/Message/MessageBagTest.php
index cbe88e179..260b26284 100644
--- a/src/platform/tests/Message/MessageBagTest.php
+++ b/src/platform/tests/Message/MessageBagTest.php
@@ -48,26 +48,6 @@ public function testGetSystemMessageWithoutSystemMessage()
         $this->assertNull($messageBag->getSystemMessage());
     }
 
-    public function testWith()
-    {
-        $messageBag = new MessageBag(
-            Message::forSystem('My amazing system prompt.'),
-            Message::ofAssistant('It is time to sleep.'),
-            Message::ofUser('Hello, world!'),
-        );
-
-        $newMessage = Message::ofAssistant('It is time to wake up.');
-        $newMessageBag = $messageBag->with($newMessage);
-
-        $this->assertCount(3, $messageBag);
-        $this->assertCount(4, $newMessageBag);
-
-        $newMessageFromBag = $newMessageBag->getMessages()[3];
-
-        $this->assertInstanceOf(AssistantMessage::class, $newMessageFromBag);
-        $this->assertSame('It is time to wake up.', $newMessageFromBag->getContent());
-    }
-
     public function testMerge()
     {
         $messageBag = new MessageBag(
@@ -121,7 +101,7 @@ public function testPrepend()
         );
 
         $newMessage = Message::forSystem('My amazing system prompt.');
-        $newMessageBag = $messageBag->prepend($newMessage);
+        $newMessageBag = (clone $messageBag)->prepend($newMessage);
 
         $this->assertCount(2, $messageBag);
         $this->assertCount(3, $newMessageBag);