diff --git a/src/Response/SseResponse.php b/src/Response/SseResponse.php
index d080f57..79ea478 100644
--- a/src/Response/SseResponse.php
+++ b/src/Response/SseResponse.php
@@ -96,7 +96,21 @@ public function __construct(iterable|\Closure $producer, array $options = [])
                         return;
                     }
 
-                    $emitter->send($event);
+                    if ($event instanceof Event || is_string($event) || is_array($event)) {
+                        $emitter->send($event);
+                        continue;
+                    }
+
+                    $sendObject = [$emitter, 'sendObject'];
+
+                    if (is_callable($sendObject)) {
+                        $sendObject($event);
+                        continue;
+                    }
+
+                    throw new InvalidArgumentException(
+                        'The current SSE emitter does not support object events; implement ObjectEmitterInterface.'
+                    );
                 }
             };
     }
diff --git a/src/Sse/AbstractEmitter.php b/src/Sse/AbstractEmitter.php
index c510b4d..469825c 100644
--- a/src/Sse/AbstractEmitter.php
+++ b/src/Sse/AbstractEmitter.php
@@ -8,12 +8,22 @@
  * SSE 发送器公共实现。
  *
  * 统一帧归一化、注释帧、重连间隔和关闭状态；具体运行时只需实现 write()。
+ * 对象事件通过 ObjectEmitterInterface::sendObject() 提供，保持 send() 的旧签名。
  */
-abstract class AbstractEmitter implements EmitterInterface
+abstract class AbstractEmitter implements ObjectEmitterInterface
 {
     protected bool $closed = false;
 
-    public function send(string|array|object $event): void
+    public function send(Event|string|array $event): void
+    {
+        if ($this->isClosed()) {
+            return;
+        }
+
+        $this->write($this->normalize($event)->format());
+    }
+
+    public function sendObject(object $event): void
     {
         if ($this->isClosed()) {
             return;
diff --git a/src/Sse/EmitterInterface.php b/src/Sse/EmitterInterface.php
index 8b7a583..7311adc 100644
--- a/src/Sse/EmitterInterface.php
+++ b/src/Sse/EmitterInterface.php
@@ -15,9 +15,9 @@ interface EmitterInterface
     /**
      * 发送一条事件。
      *
-     * @param Event|string|array<array-key, mixed>|object $event string 作为 data；数组/对象 JSON 编码
+     * @param Event|string|array<array-key, mixed> $event string 作为 data；数组 JSON 编码
      */
-    public function send(string|array|object $event): void;
+    public function send(Event|string|array $event): void;
 
     /**
      * 发送注释帧（常用于心跳）。
diff --git a/src/Sse/ObjectEmitterInterface.php b/src/Sse/ObjectEmitterInterface.php
new file mode 100644
index 0000000..bc8305c
--- /dev/null
+++ b/src/Sse/ObjectEmitterInterface.php
@@ -0,0 +1,19 @@
+<?php
+
+declare(strict_types=1);
+
+namespace FastD\Http\Sse;
+
+/**
+ * 可选能力：支持对象事件的 SSE 发送器。
+ *
+ * 保持 EmitterInterface::send() 的参数类型不变，避免破坏已有自定义实现；
+ * 需要发送对象时使用 sendObject()。
+ */
+interface ObjectEmitterInterface extends EmitterInterface
+{
+    /**
+     * 发送对象事件；对象会由 Event::data() 序列化为 JSON。
+     */
+    public function sendObject(object $event): void;
+}
diff --git a/tests/sse/CgiEmitterTest.php b/tests/sse/CgiEmitterTest.php
index 195ecfc..512381b 100644
--- a/tests/sse/CgiEmitterTest.php
+++ b/tests/sse/CgiEmitterTest.php
@@ -36,7 +36,7 @@ public function testSendAcceptsStringArrayAndEvent(): void
 
         $emitter->send('hello');
         $emitter->send(['name' => 'fastd']);
-        $emitter->send((object) ['source' => 'object']);
+        $emitter->sendObject((object) ['source' => 'object']);
         $emitter->send(new Event('done', 'done', '9'));
 
         $this->assertSame([
diff --git a/tests/sse/SseResponseTest.php b/tests/sse/SseResponseTest.php
index 9654fb9..43e1140 100644
--- a/tests/sse/SseResponseTest.php
+++ b/tests/sse/SseResponseTest.php
@@ -8,6 +8,7 @@
 use FastD\Http\Response\StreamingResponseInterface;
 use FastD\Http\Sse\EmitterInterface;
 use FastD\Http\Sse\Event;
+use FastD\Http\Sse\ObjectEmitterInterface;
 use InvalidArgumentException;
 use PHPUnit\Framework\TestCase;
 use Psr\Http\Message\ResponseInterface;
@@ -50,6 +51,7 @@ public function testIterableProducerIsWrapped(): void
         $response = new SseResponse([
             'a',
             ['b' => 2],
+            (object) ['d' => 4],
             Event::data('c', 'custom', '3'),
         ]);
 
@@ -59,6 +61,7 @@ public function testIterableProducerIsWrapped(): void
         $this->assertSame([
             "data: a\n\n",
             "data: {\"b\":2}\n\n",
+            "data: {\"d\":4}\n\n",
             "id: 3\nevent: custom\ndata: c\n\n",
         ], $emitter->frames);
     }
@@ -170,11 +173,16 @@ public function testCloneKeepsProducerAndOptions(): void
      */
     private function collectingEmitter(): EmitterInterface
     {
-        return new class implements EmitterInterface {
+        return new class implements ObjectEmitterInterface {
             /** @var list<string> */
             public array $frames = [];
 
-            public function send(string|array|object $event): void
+            public function send(Event|string|array $event): void
+            {
+                $this->frames[] = ($event instanceof Event ? $event : Event::data($event))->format();
+            }
+
+            public function sendObject(object $event): void
             {
                 $this->frames[] = ($event instanceof Event ? $event : Event::data($event))->format();
             }