feat(desktop): render AI-output videos inline as <video> (mp4/webm/mov)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

desktop/src/components/chat/AssistantMessage.linkrouting.test.tsx

@@ -111,6 +111,23 @@ describe('AssistantMessage output-target cards', () => {
     expect(screen.queryByText('assistantOutputs.kind.image')).toBeNull()
   })
 
+  it('renders a relative video inline (a <video>) but NOT as a card', () => {
+    const { container } = render(
+      <AssistantMessage
+        sessionId="s1"
+        content={'生成的视频见 outputs/demo.mp4'}
+        isStreaming={false}
+      />,
+    )
+    // Video renders inline through InlineVideoGallery (workDir is undefined in this
+    // test's mock, so the relative path resolves as-is and is served via /preview-fs).
+    const video = container.querySelector('video') as HTMLVideoElement
+    expect(video).not.toBeNull()
+    expect(video.getAttribute('src')).toBe('http://127.0.0.1:4321/preview-fs/s1/outputs/demo.mp4')
+    // ...and is NOT duplicated as an output-target card (no extra open/copy controls).
+    expect(screen.queryByText('assistantOutputs.kind.image')).toBeNull()
+  })
+
   it('still renders md/html/localhost cards when those references are present', () => {
     render(
       <AssistantMessage

desktop/src/components/chat/AssistantMessage.tsx

@@ -3,6 +3,7 @@ import type { MouseEvent as ReactMouseEvent } from 'react'
 import { MarkdownRenderer } from '../markdown/MarkdownRenderer'
 import { MessageActionBar, type MessageBranchAction } from './MessageActionBar'
 import { InlineImageGallery } from './InlineImageGallery'
+import { InlineVideoGallery } from './InlineVideoGallery'
 import { AssistantOutputTargetCard } from './AssistantOutputTargetCard'
 import { handlePreviewLink } from '../../lib/handlePreviewLink'
 import { getServerBaseUrl } from '../../lib/desktopRuntime'
@@ -50,8 +51,10 @@ export const AssistantMessage = memo(function AssistantMessage({ content, isStre
     () =>
       isStreaming || !sessionId
         ? []
-        : // Image targets render inline via <InlineImageGallery>; never also as a card.
-          extractAssistantOutputTargets(content, { workDir }).filter((target) => target.kind !== 'image'),
+        : // Image/video targets render inline (InlineImageGallery/InlineVideoGallery); never also as a card.
+          extractAssistantOutputTargets(content, { workDir }).filter(
+            (target) => target.kind !== 'image' && target.kind !== 'video',
+          ),
     [content, isStreaming, sessionId, workDir],
   )
 
@@ -80,6 +83,7 @@ export const AssistantMessage = memo(function AssistantMessage({ content, isStre
             onLinkClick={sessionId ? handleLinkClick : undefined}
           />
           {!isStreaming && <InlineImageGallery text={content} sessionId={sessionId} workDir={workDir} />}
+          {!isStreaming && <InlineVideoGallery text={content} sessionId={sessionId} workDir={workDir} />}
           {isStreaming && (
             <span className="ml-0.5 inline-block h-4 w-0.5 animate-shimmer bg-[var(--color-brand)] align-text-bottom" />
           )}

desktop/src/components/chat/InlineVideoGallery.test.tsx

@@ -0,0 +1,60 @@
+import '@testing-library/jest-dom'
+import { render } from '@testing-library/react'
+import { describe, expect, it, vi } from 'vitest'
+
+// getServerBaseUrl backs the relative-path src (/preview-fs/<sessionId>/...).
+vi.mock('../../lib/desktopRuntime', () => ({
+  getServerBaseUrl: () => 'http://127.0.0.1:4321',
+}))
+
+import { InlineVideoGallery } from './InlineVideoGallery'
+
+function videoSrcs(container: HTMLElement): string[] {
+  return Array.from(container.querySelectorAll('video')).map((v) => v.getAttribute('src') ?? '')
+}
+
+describe('InlineVideoGallery', () => {
+  it('renders a relative workspace video via previewFsUrl when sessionId is provided', () => {
+    const { container } = render(
+      <InlineVideoGallery text={'render saved to outputs/demo.mp4'} sessionId="s1" workDir="/w" />,
+    )
+
+    const srcs = videoSrcs(container)
+    expect(srcs).toHaveLength(1)
+    expect(srcs[0]).toBe('http://127.0.0.1:4321/preview-fs/s1/outputs/demo.mp4')
+  })
+
+  it('uses preload="metadata" and never autoplays', () => {
+    const { container } = render(
+      <InlineVideoGallery text={'clip at outputs/demo.mp4'} sessionId="s1" workDir="/w" />,
+    )
+
+    const video = container.querySelector('video')!
+    expect(video).toHaveAttribute('preload', 'metadata')
+    expect(video).not.toHaveAttribute('autoplay')
+    expect(video).not.toHaveAttribute('loop')
+  })
+
+  it('renders nothing when sessionId is absent', () => {
+    const { container } = render(<InlineVideoGallery text={'clip at outputs/demo.mp4'} />)
+    expect(container.querySelectorAll('video')).toHaveLength(0)
+  })
+
+  it('renders nothing when there are no video paths', () => {
+    const { container } = render(
+      <InlineVideoGallery text={'just some text and an image outputs/a.png'} sessionId="s1" workDir="/w" />,
+    )
+    expect(container.querySelectorAll('video')).toHaveLength(0)
+  })
+
+  it('deduplicates a repeated video path', () => {
+    const { container } = render(
+      <InlineVideoGallery
+        text={'see outputs/demo.mp4 and again outputs/demo.mp4'}
+        sessionId="s1"
+        workDir="/w"
+      />,
+    )
+    expect(container.querySelectorAll('video')).toHaveLength(1)
+  })
+})

desktop/src/components/chat/InlineVideoGallery.tsx

@@ -0,0 +1,84 @@
+import { useMemo } from 'react'
+import { extractAssistantOutputTargets } from '../../lib/assistantOutputTargets'
+import { previewFsUrl } from '../../lib/handlePreviewLink'
+import { getServerBaseUrl } from '../../lib/desktopRuntime'
+
+type GalleryVideo = {
+  src: string
+  name: string
+}
+
+type Props = {
+  text: string
+  /**
+   * Required to build a `/preview-fs/<sessionId>/...` URL. When absent (e.g.
+   * tool-log usage) nothing renders — relative workspace videos can't be served
+   * without a session, and we deliberately keep media out of tool logs.
+   */
+  sessionId?: string
+  workDir?: string | null
+}
+
+/**
+ * Renders AI-output video paths (mp4/webm/mov/m4v) inline, mirroring
+ * {@link InlineImageGallery}. Only relative workspace paths are surfaced (via the
+ * sandboxed target extractor + `/preview-fs`); videos are large so we use a
+ * vertical stack, `preload="metadata"`, and never autoplay.
+ */
+export function InlineVideoGallery({ text, sessionId, workDir }: Props) {
+  const videos = useMemo<GalleryVideo[]>(() => {
+    if (!sessionId) {
+      return []
+    }
+
+    const base = getServerBaseUrl()
+    const targets = extractAssistantOutputTargets(text, { workDir }).filter(
+      (target) => target.kind === 'video',
+    )
+
+    const seenSrc = new Set<string>()
+    const result: GalleryVideo[] = []
+
+    for (const target of targets) {
+      const relPath = target.normalizedPath ?? target.href
+      const src = previewFsUrl(base, sessionId, relPath)
+      if (seenSrc.has(src)) {
+        continue
+      }
+      seenSrc.add(src)
+      result.push({ src, name: relPath.split('/').pop() ?? '' })
+    }
+
+    return result
+  }, [sessionId, text, workDir])
+
+  if (videos.length === 0) return null
+
+  return (
+    <div className="mt-3 space-y-2">
+      {videos.map((video) => (
+        <div
+          key={video.src}
+          className="overflow-hidden rounded-xl border border-[var(--color-border)] bg-[var(--color-surface-container-low)] shadow-sm"
+        >
+          <video
+            src={video.src}
+            controls
+            preload="metadata"
+            playsInline
+            className="w-full rounded-t-xl bg-black"
+            style={{ maxHeight: 420 }}
+            onError={(e) => {
+              // Hide the whole container when the video can't be loaded.
+              (e.target as HTMLVideoElement).closest('div')!.style.display = 'none'
+            }}
+          />
+          <div className="flex items-center gap-1.5 px-2.5 py-1.5 text-[10px] font-medium text-[var(--color-text-tertiary)]">
+            <span className="material-symbols-outlined text-[12px]">movie</span>
+            <span className="truncate">{video.name}</span>
+          </div>
+        </div>
+      ))}
+    </div>
+  )
+}

desktop/src/lib/assistantOutputTargets.test.ts

@@ -21,6 +21,38 @@ describe('extractAssistantOutputTargets', () => {
     ])
   })
 
+  it('detects a naked relative video path as a video target', () => {
+    const targets = extractAssistantOutputTargets('渲染完成，见 outputs/clip.mp4 。', { workDir })
+
+    expect(targets).toMatchObject([
+      {
+        kind: 'video',
+        href: 'outputs/clip.mp4',
+        normalizedPath: 'outputs/clip.mp4',
+        source: 'plain-path',
+      },
+    ])
+  })
+
+  it('detects a markdown link to a video as a video target', () => {
+    const targets = extractAssistantOutputTargets('[v](demo.webm)', { workDir })
+
+    expect(targets).toMatchObject([
+      {
+        kind: 'video',
+        href: 'demo.webm',
+        normalizedPath: 'demo.webm',
+        source: 'markdown-link',
+      },
+    ])
+  })
+
+  it('rejects a video path outside the active workspace (sandbox)', () => {
+    const targets = extractAssistantOutputTargets('[bad](/etc/x.mp4)', { workDir })
+
+    expect(targets).toEqual([])
+  })
+
   it('normalizes markdown destinations with angle brackets, spaces, and line suffixes', () => {
     const content = [
       '[html](</Users/nanmi/project/demo/My Page/index.html>)',

desktop/src/lib/assistantOutputTargets.ts

@@ -2,6 +2,7 @@ export type AssistantOutputTargetKind =
   | 'local-html'
   | 'localhost-url'
   | 'image'
+  | 'video'
   | 'markdown'
 
 export type AssistantOutputTargetSource =
@@ -64,7 +65,7 @@ type DirectoryTreeFileMatch = {
 const localhostUrlPattern =
   /https?:\/\/(?:localhost|127\.0\.0\.1|\[::1\])(?::\d+)?(?:\/[^\s`"'<>，。；、）\])}]*)?/gi
 const previewablePathPattern =
-  /(^|[\s("'`[])((?:\.{1,2}\/)?(?:[\w.-]+\/)*[\w.-]+\.(?:html?|md|markdown|png|jpe?g|gif|webp|svg))(?![\w/-])/gi
+  /(^|[\s("'`[])((?:\.{1,2}\/)?(?:[\w.-]+\/)*[\w.-]+\.(?:html?|md|markdown|png|jpe?g|gif|webp|svg|mp4|webm|mov|m4v))(?![\w/-])/gi
 
 export function extractAssistantOutputTargets(
   content: string,
@@ -283,6 +284,10 @@ function classifyFileTarget(candidate: string): FileTargetMatch['kind'] | null {
     return 'image'
   }
 
+  if (['.mp4', '.webm', '.mov', '.m4v'].includes(extension)) {
+    return 'video'
+  }
+
   return null
 }
 
@@ -388,7 +393,7 @@ function normalizeMarkdownDestination(destination: string): string {
     normalized = normalized.slice(1, -1).trim()
   }
 
-  const lineSuffixMatch = normalized.match(/^(.*\.(?:html?|md|markdown|png|jpe?g|gif|webp|svg)):\d+$/i)
+  const lineSuffixMatch = normalized.match(/^(.*\.(?:html?|md|markdown|png|jpe?g|gif|webp|svg|mp4|webm|mov|m4v)):\d+$/i)
   const lineSuffixedPath = lineSuffixMatch?.[1]
 
   if (lineSuffixedPath && !isExternalUrl(lineSuffixedPath)) {