diff --git a/src/components/image-editor/EditorAgentConversation/MessageBubble.test.tsx b/src/components/image-editor/EditorAgentConversation/MessageBubble.test.tsx
index af52065ff..3a083b04f 100644
--- a/src/components/image-editor/EditorAgentConversation/MessageBubble.test.tsx
+++ b/src/components/image-editor/EditorAgentConversation/MessageBubble.test.tsx
@@ -97,14 +97,24 @@ describe('MessageBubble', () => {
   });
 
   it('copies an attached WebP as PNG without opening the message text menu', async () => {
-    const clipboardWrite = vi.fn().mockResolvedValue(undefined);
+    let resolveAssetRead!: (response: Response) => void;
+    const pendingAssetRead = new Promise<Response>((resolve) => {
+      resolveAssetRead = resolve;
+    });
+    const clipboardWrite = vi.fn(
+      async (
+        items: Array<{ items: Record<string, Blob | PromiseLike<Blob>> }>,
+      ) => {
+        await items[0]?.items['image/png'];
+      },
+    );
     Object.defineProperty(navigator, 'clipboard', {
       configurable: true,
       value: { write: clipboardWrite },
     });
     const ClipboardItemMock = vi.fn(function (
-      this: { items: Record<string, Blob> },
-      items: Record<string, Blob>,
+      this: { items: Record<string, Blob | PromiseLike<Blob>> },
+      items: Record<string, Blob | PromiseLike<Blob>>,
     ) {
       this.items = items;
     });
@@ -127,11 +137,7 @@ describe('MessageBubble', () => {
     vi.spyOn(HTMLCanvasElement.prototype, 'toBlob').mockImplementation(
       (callback) => callback(new Blob(['png'], { type: 'image/png' })),
     );
-    vi.mocked(readAssetBytes).mockResolvedValue({
-      blob: vi
-        .fn()
-        .mockResolvedValue(new Blob(['webp'], { type: 'image/webp' })),
-    } as unknown as Response);
+    vi.mocked(readAssetBytes).mockReturnValue(pendingAssetRead);
     const { container } = renderMessage({
       id: 5,
       role: 'user',
@@ -158,14 +164,21 @@ describe('MessageBubble', () => {
     expect(screen.queryByRole('menuitem', { name: '复制文本' })).toBeNull();
     fireEvent.click(screen.getByRole('menuitem', { name: '复制图片' }));
 
-    await waitFor(() => expect(clipboardWrite).toHaveBeenCalledTimes(1));
+    // The clipboard write starts synchronously, before private asset loading completes.
+    expect(clipboardWrite).toHaveBeenCalledTimes(1);
     expect(readAssetBytes).toHaveBeenCalledWith(
       '/generated-editor-images/private.webp',
       { objectKey: 'editor/private.webp' },
     );
     expect(ClipboardItemMock).toHaveBeenCalledWith({
-      'image/png': expect.any(Blob),
+      'image/png': expect.any(Promise),
     });
+    resolveAssetRead({
+      blob: vi
+        .fn()
+        .mockResolvedValue(new Blob(['webp'], { type: 'image/webp' })),
+    } as unknown as Response);
+    await screen.findByRole('menuitem', { name: '已复制' });
     expect(bitmapClose).toHaveBeenCalledTimes(1);
   });
 
diff --git a/src/components/image-editor/EditorAgentConversation/useRightClickMenu.ts b/src/components/image-editor/EditorAgentConversation/useRightClickMenu.ts
index 9f3be4b24..bc4e39217 100644
--- a/src/components/image-editor/EditorAgentConversation/useRightClickMenu.ts
+++ b/src/components/image-editor/EditorAgentConversation/useRightClickMenu.ts
@@ -93,10 +93,11 @@ async function copyAssetImage(asset: EditorAgentContextAsset) {
     return false;
   }
   try {
-    const response = await readAssetBytes(asset.source, {
+    const pngBlob = readAssetBytes(asset.source, {
       objectKey: asset.objectKey,
-    });
-    const pngBlob = await convertImageBlobToPng(await response.blob());
+    }).then(async (response) => convertImageBlobToPng(await response.blob()));
+    // Clipboard write must start in the menu click's user-activation stack.
+    // Safari accepts promised ClipboardItem data and resolves it after asset loading/conversion.
     await navigator.clipboard.write([
       new ClipboardItem({ 'image/png': pngBlob }),
     ]);