@@ -31,11 +31,12 @@ export const registerShellHandlers = (): void => {
     }
   })
 
-  ipcMain.on('mt::clipboard::write-text', (_e, text: string) => {
+  ipcMain.handle('mt::clipboard::write-text', (_e, text: string) => {
     try {
       clipboard.writeText(text)
-    } catch (err) {
-      log.error('clipboard.writeText failed:', err)
+      return true
+    } catch {
+      return false
     }
   })
   ipcMain.handle('mt::clipboard::write-image', (_e, png: Uint8Array) => {
@@ -74,7 +75,12 @@ export const registerShellHandlers = (): void => {
         // UTF-16LE instead, then take the first non-empty entry.
         const buffer = clipboard.readBuffer('FileNameW')
         if (buffer.length > 0) {
-          return buffer.toString('utf16le').split('\u0000').find(p => p.length > 0) ?? ''
+          return (
+            buffer
+              .toString('utf16le')
+              .split('\u0000')
+              .find((p) => p.length > 0) ?? ''
+          )
         }
         return ''
       }
 
@@ -76,7 +76,7 @@ const shellAPI = {
 }
 
 const clipboardAPI = {
-  writeText: (text: string) => send('mt::clipboard::write-text', text),
+  writeText: (text: string) => invoke('mt::clipboard::write-text', text),
   readText: () => invoke('mt::clipboard::read-text'),
   guessFilePath: () => invoke('mt::clipboard::guess-file-path'),
   writeImage: (png: Uint8Array) => invoke('mt::clipboard::write-image', png)
 
@@ -1818,6 +1818,7 @@ onMounted(() => {
     clipboardFilePath: guessClipboardFilePath,
     // Read the OS clipboard's plain text for "Paste as Plain Text" (execCommand('paste') no longer fires).
     clipboardText: () => window.electron.clipboard.readText(),
+    clipboardWriteText: window.electron.clipboard.writeText,
     fetchLinkHtml: (url) => window.electron.fetchLinkHtml(url),
     // Image-persist callbacks read by the engine's clipboard + drag-drop handlers
     // from `muya.options.*` (distinct from the ImageEditTool plugin option above).
 
@@ -50,6 +50,7 @@ export type PlantumlFetchResult =
 // =================================================================
 
 export interface IpcInvokeChannels {
+  'mt::clipboard::write-text': { args: [text: string]; ret: boolean }
   'mt::ask-for-image-path': { args: []; ret: string[] }
   'mt::boot-info-async': { args: []; ret: BootInfo }
   'mt::clipboard::guess-file-path': { args: []; ret: string | null }
@@ -130,7 +131,6 @@ export interface IpcSendChannels {
   'mt::ask-for-user-data': []
   'mt::ask-for-user-preference': []
   'mt::check-for-update': []
-  'mt::clipboard::write-text': [text: string]
   'mt::close-window': []
   'mt::close-window-confirm': [unsavedFiles: UnsavedFile[]]
   'mt::cmd-close-window': []
 
@@ -51,7 +51,7 @@ declare global {
   }
 
   interface ElectronClipboardAPI {
-    writeText(text: string): void
+    writeText(text: string): Promise<boolean>
     readText(): Promise<string>
     guessFilePath(): Promise<string | null>
     writeImage(png: Uint8Array): Promise<boolean>
 
@@ -0,0 +1,59 @@
+import { expect, test } from '@playwright/test'
+import type { ElectronApplication, Page } from 'playwright'
+import { launchWithMarkdown } from './helpers'
+
+let app: ElectronApplication
+let page: Page
+
+test.beforeAll(async() => {
+  const launched = await launchWithMarkdown('```js\nconst value = 1\n```\n', {
+    preferences: { language: 'en' }
+  })
+  app = launched.app
+  page = launched.page
+})
+
+test.afterEach(async() => {
+  await app.evaluate(({ clipboard }) => {
+    const state = globalThis as typeof globalThis & {
+      __originalWriteText?: typeof clipboard.writeText
+    }
+    if (state.__originalWriteText) {
+      clipboard.writeText = state.__originalWriteText
+      delete state.__originalWriteText
+    }
+  })
+})
+
+test.afterAll(async() => {
+  if (app) await app.close()
+})
+
+test('the shared clipboard API returns success without a duplicate send listener', async() => {
+  expect(await page.evaluate(() => window.electron.clipboard.writeText('shared clipboard API'))).toBe(true)
+  expect(await app.evaluate(({ clipboard }) => clipboard.readText())).toBe('shared clipboard API')
+  expect(await app.evaluate(({ ipcMain }) => ipcMain.listenerCount('mt::clipboard::write-text'))).toBe(0)
+})
+
+test('code copying uses the shared API and reports success', async() => {
+  await page.locator('.mu-code-block').hover()
+  const button = page.locator('button.mu-code-copy')
+  await button.click()
+  await expect(button).toHaveAttribute('data-copy-feedback', 'Copied')
+  expect(await app.evaluate(({ clipboard }) => clipboard.readText())).toBe('const value = 1')
+})
+
+test('native clipboard failures return false and show failure feedback', async() => {
+  await app.evaluate(({ clipboard }) => {
+    const state = globalThis as typeof globalThis & {
+      __originalWriteText?: typeof clipboard.writeText
+    }
+    state.__originalWriteText = clipboard.writeText
+    clipboard.writeText = () => { throw new Error('clipboard unavailable') }
+  })
+  expect(await page.evaluate(() => window.electron.clipboard.writeText('not copied'))).toBe(false)
+  await page.locator('.mu-code-block').hover()
+  const button = page.locator('button.mu-code-copy')
+  await button.click()
+  await expect(button).toHaveAttribute('data-copy-feedback', 'Copy failed. Please try again.')
+})
@@ -82,7 +82,7 @@ test('the scroll area outside the text column keeps the arrow', async() => {
 
 test('clickable content keeps the hand cursor', async() => {
   for (const selector of [
-    '.mu-container a',
+    '.mu-container button.mu-code-copy',
     '.mu-container input[type=checkbox]'
   ]) {
     expect(await cursorOf(selector), selector).toBe('pointer')
 
@@ -96,6 +96,16 @@ describe('locale completeness', () => {
         }
     });
 
+    describe('clipboard translations', () => {
+        for (const [tag, locale] of nonEnLocales) {
+            it(`${tag} translates clipboard messages`, () => {
+                for (const key of ['Copied', 'Copy failed'] as const) {
+                    expect(locale.resource[key], `${tag}: ${key}`).not.toBe(en.resource[key]);
+                }
+            });
+        }
+    });
+
     describe('every resource value is a non-empty string', () => {
         for (const [tag, locale] of [['en', en] as [string, typeof en], ...nonEnLocales]) {
             it(`${tag} has only non-empty string values`, () => {
 
@@ -273,3 +273,31 @@ body {
 
     background: var(--highlight-color);
 }
+
+.mu-code-copy {
+    background: transparent;
+    border: 0;
+}
+
+.mu-code-block:hover > .mu-code-copy,
+.mu-code-block > .mu-code-copy:focus-visible {
+    opacity: 1;
+}
+
+.mu-code-copy[data-copy-feedback]::after {
+    position: absolute;
+    right: 0;
+    bottom: 100%;
+
+    padding: 4px 8px;
+
+    color: var(--editor-color);
+    font: 12px sans-serif;
+    white-space: nowrap;
+
+    background: var(--float-bg-color);
+    border-radius: 4px;
+    box-shadow: var(--float-shadow);
+
+    content: attr(data-copy-feedback);
+}
@@ -4,14 +4,6 @@ import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
 import { CopyType } from '../../../../clipboard/types';
 import { Muya } from '../../../../muya';
 
-// Characterization coverage for the code-block copy button wiring
-// (Code._listen, code.ts:104-134). copyHandler.spec only exercises the
-// downstream COPY_CODE_CONTENT setData branch — the button-click →
-// editor.clipboard.copy(CopyType.COPY_CODE_CONTENT, text) hookup is otherwise
-// untested. The button is the `a.mu-code-copy` first child of the `.mu-code`
-// node; clicking it copies the raw code text verbatim, and mousedown
-// preventDefaults so the caret/selection does not move.
-
 const bootedHosts: HTMLElement[] = [];
 
 beforeEach(() => {
@@ -24,6 +16,7 @@ afterEach(() => {
         host.remove();
     }
     vi.restoreAllMocks();
+    vi.useRealTimers();
 });
 
 function bootMuya(markdown: string, options: Record<string, unknown> = {}): Muya {
@@ -42,7 +35,7 @@ describe('code-block copy button', () => {
         const muya = bootMuya(THREE_LINE_FENCE);
         const copySpy = vi.spyOn(muya.editor.clipboard, 'copy').mockImplementation(() => {});
 
-        const button = muya.domNode.querySelector<HTMLElement>('a.mu-code-copy');
+        const button = muya.domNode.querySelector<HTMLElement>('.mu-code-copy');
         expect(button).not.toBeNull();
 
         button!.dispatchEvent(new MouseEvent('click', { bubbles: true }));
@@ -58,17 +51,33 @@ describe('code-block copy button', () => {
         const muya = bootMuya('```js\nsolo line\n```\n');
         const copySpy = vi.spyOn(muya.editor.clipboard, 'copy').mockImplementation(() => {});
 
-        const button = muya.domNode.querySelector<HTMLElement>('a.mu-code-copy')!;
+        const button = muya.domNode.querySelector<HTMLElement>('.mu-code-copy')!;
         button.dispatchEvent(new MouseEvent('click', { bubbles: true }));
 
         expect(copySpy).toHaveBeenCalledTimes(1);
         expect(copySpy).toHaveBeenCalledWith(CopyType.COPY_CODE_CONTENT, 'solo line');
     });
 
+    it.each(['false', 'reject'])('restores the accessible label after a %s clipboard failure', async (failure) => {
+        vi.useFakeTimers();
+        const writer = failure === 'reject'
+            ? vi.fn().mockRejectedValue(new Error('clipboard unavailable'))
+            : vi.fn().mockResolvedValue(false);
+        const muya = bootMuya(THREE_LINE_FENCE, { clipboardWriteText: writer });
+        const button = muya.domNode.querySelector<HTMLButtonElement>('.mu-code-copy')!;
+        button.click();
+        await vi.advanceTimersByTimeAsync(0);
+        expect(button.getAttribute('aria-label')).toBe(muya.i18n.t('Copy failed'));
+        expect(button.dataset.copyFeedback).toBe(muya.i18n.t('Copy failed'));
+        await vi.advanceTimersByTimeAsync(2000);
+        expect(button.getAttribute('aria-label')).toBe(muya.i18n.t('Copy content'));
+        expect(button.dataset.copyFeedback).toBeUndefined();
+    });
+
     it('preventDefaults the mousedown so the caret/selection does not move', () => {
         const muya = bootMuya(THREE_LINE_FENCE);
 
-        const button = muya.domNode.querySelector<HTMLElement>('a.mu-code-copy')!;
+        const button = muya.domNode.querySelector<HTMLElement>('.mu-code-copy')!;
         const mousedown = new MouseEvent('mousedown', { bubbles: true, cancelable: true });
         button.dispatchEvent(mousedown);
Original file line number	Diff line number	Diff line change
`@@ -76,7 +76,7 @@ const shellAPI = {`
`76`	`76`	`}`
`77`	`77`
`78`	`78`	`const clipboardAPI = {`
`79`		`- writeText: (text: string) => send('mt::clipboard::write-text', text),`
	`79`	`+ writeText: (text: string) => invoke('mt::clipboard::write-text', text),`
`80`	`80`	`readText: () => invoke('mt::clipboard::read-text'),`
`81`	`81`	`guessFilePath: () => invoke('mt::clipboard::guess-file-path'),`
`82`	`82`	`writeImage: (png: Uint8Array) => invoke('mt::clipboard::write-image', png)`
Original file line number	Diff line number	Diff line change
`@@ -51,7 +51,7 @@ declare global {`
`51`	`51`	`}`
`52`	`52`
`53`	`53`	`interface ElectronClipboardAPI {`
`54`		`- writeText(text: string): void`
	`54`	`+ writeText(text: string): Promise<boolean>`
`55`	`55`	`readText(): Promise<string>`
`56`	`56`	`guessFilePath(): Promise<string \| null>`
`57`	`57`	`writeImage(png: Uint8Array): Promise<boolean>`