/cue

Playwright Configuration for Demo Recording

Configuration guide for demo video recording with Playwright 1.59 ("Agentic Release", 2026-04).

Purpose: Read this when Cue must choose demo-specific Playwright configuration, recording APIs, aspect-ratio presets, device profiles, output formats, naming conventions, environment variables, CI, or troubleshooting steps.

Contents:

• Recording API Selection: page.screencast (primary, 1.59 Stable) vs recordVideo (failure receipts)
• Basic Configuration: demo-dedicated Playwright config
• Aspect Ratio Presets: 16:9 / 9:16 / 4:5 / 1:1 with viewport + video.size pairings
• Device-Specific Project Settings: desktop, mobile, and tablet presets
• Video Recording Settings: video mode, resolution, and codec matrix (VP9 / AV1 / H.264)
• page.screencast API Recipes: start/stop, showActions, showChapter, showOverlay, onFrame
• Vision-Stream (onFrame): JPEG streaming to Vision Models
• slowMo Configuration Guide: pace ranges and usage rules
• Output Formats and Conversion: WebM baseline plus MP4/AV1/GIF conversion
• Output File Naming Conventions: canonical demo naming patterns
• Environment Variables: .env.demo defaults
• CI/CD Configuration: GitHub Actions recording flow
• Directory Structure: expected demo file layout
• Browser Engine Notes: Chrome for Testing (v1.57+), browser.bind (v1.59 Stable), incremental snapshot
• Playwright MCP vs CLI for Agentic Recording: decision matrix for receipt capture
• Troubleshooting: common recording failures and fixes

Recording API Selection

Since Playwright 1.59 (April 2026, "Agentic Release"), page.screencast is the primary recording API for Cue. recordVideo remains useful for failure-only receipts and legacy single-page full-session captures.

Both APIs silently downscale to 800×800 when size is omitted. Always set size explicitly.

// PRIMARY: page.screencast (Playwright ≥ 1.59)
const screencast = await page.screencast.start({
  path: 'demos/output/checkout_complete_16x9_20260515.webm',
  size: { width: 1920, height: 1080 },
  quality: 90,           // 1–100, JPEG-frame quality
  // onFrame: (jpegBuffer, ts) => stream to Vision Model
});
await screencast.showChapter({ title: 'Step 1 — Add to cart', duration: 2000 });
await screencast.showActions({ position: 'top-right', duration: 500, fontSize: 24 });
// ... demo flow ...
await screencast.stop();

// SECONDARY: recordVideo (failure receipts)
use: {
  video: { mode: 'retain-on-failure', size: { width: 1920, height: 1080 } }
}

Basic Configuration

Demo-Dedicated Configuration File

// playwright.config.demo.ts
import { defineConfig, devices } from '@playwright/test';

export default defineConfig({
  // === Test Settings ===
  testDir: './demos/specs',
  timeout: 180000,         // 3 minutes (long-form demos with chapters)
  retries: 0,              // Demos should be deterministic
  workers: 1,              // Sequential execution for consistent timing

  // === Reporters ===
  reporter: [
    ['list'],
    ['html', { outputFolder: 'demos/report' }],
  ],

  use: {
    // === Browser Settings ===
    headless: false,
    launchOptions: {
      slowMo: 500,
      args: [
        '--disable-blink-features=AutomationControlled',
        '--disable-infobars',
      ],
    },

    // === Video Settings (recordVideo fallback for failure receipts) ===
    video: {
      mode: 'retain-on-failure',
      size: { width: 1920, height: 1080 },   // explicit — Playwright scales to 800×800 if omitted
    },

    // === Default 16:9 viewport (override per project for 9:16 / 4:5 / 1:1) ===
    viewport: { width: 1920, height: 1080 },
    locale: 'ja-JP',
    timezoneId: 'Asia/Tokyo',

    // === Network (deterministic demo runs) ===
    serviceWorkers: 'block',
  },
});

Demos primarily use page.screencast inside tests for chapter control. recordVideo in this config exists as a safety net for unexpected failures and as a fallback for very long single-context sessions.

Aspect Ratio Presets

Pick the aspect from the distribution channel before writing the recording. Reusing a 16:9 master on 9:16 or 4:5 crops the sides and loses key UI.

Project Matrix (typical)

projects: [
  {
    name: 'demo-16x9',
    use: {
      ...devices['Desktop Chrome'],
      viewport: { width: 1920, height: 1080 },
      video: { mode: 'retain-on-failure', size: { width: 1920, height: 1080 } },
    },
  },
  {
    name: 'demo-9x16-mobile',
    use: {
      ...devices['iPhone 15 Pro'],   // touch + UA
      viewport: { width: 1080, height: 1920 },
      video: { mode: 'retain-on-failure', size: { width: 1080, height: 1920 } },
      deviceScaleFactor: 1,
    },
  },
  {
    name: 'demo-4x5-linkedin',
    use: {
      ...devices['Desktop Chrome'],
      viewport: { width: 1080, height: 1350 },
      video: { mode: 'retain-on-failure', size: { width: 1080, height: 1350 } },
    },
  },
  {
    name: 'demo-1x1-producthunt',
    use: {
      ...devices['Desktop Chrome'],
      viewport: { width: 1080, height: 1080 },
      video: { mode: 'retain-on-failure', size: { width: 1080, height: 1080 } },
    },
  },
]

Aspect-Aware Re-framing

For 9:16 / 4:5, the same DOM rarely frames well. Strategies:

• Layout switch: drive the app's responsive breakpoint (use Mobile device preset).
• CSS injection: inject demo-only stylesheet to enlarge the hero region.
• Scroll-and-focus: use smoothScrollTo() + evaluate(scale) to zoom on the active widget.
• Overlay padding: pad top/bottom letterbox bars for non-responsive screens; show chapter overlays in the bars.

Device-Specific Project Settings

Desktop Settings

{
  name: 'demo-desktop',
  use: {
    ...devices['Desktop Chrome'],
    viewport: { width: 1280, height: 720 },
    launchOptions: {
      slowMo: 500,
      args: [
        '--disable-blink-features=AutomationControlled',
        '--disable-infobars',
      ],
    },
    video: {
      mode: 'on',
      size: { width: 1280, height: 720 },
    },
  },
}

Mobile Settings

{
  name: 'demo-mobile-ios',
  use: {
    ...devices['iPhone 12'],
    launchOptions: { slowMo: 600 },
    video: {
      mode: 'on',
      size: { width: 390, height: 844 },
    },
    hasTouch: true,
  },
}

{
  name: 'demo-mobile-android',
  use: {
    ...devices['Pixel 5'],
    launchOptions: { slowMo: 600 },
    video: {
      mode: 'on',
      size: { width: 393, height: 851 },
    },
    hasTouch: true,
  },
}

Tablet Settings

{
  name: 'demo-tablet',
  use: {
    ...devices['iPad Pro 11'],
    launchOptions: { slowMo: 550 },
    video: {
      mode: 'on',
      size: { width: 834, height: 1194 },
    },
  },
}

High-Fidelity Capture (HiDPI / 4K)

Three independent knobs raise demo quality. Combine for the sharpest result.

Knob 1: deviceScaleFactor (HiDPI rendering)

The single biggest win. Renders internally at DPR=2 (or 3) and downsamples to video.size, giving Retina-class fonts and icons even in a 1080p file.

// Context option (preferred — Playwright-native)
use: {
  viewport: { width: 1920, height: 1080 },
  deviceScaleFactor: 2,                          // HiDPI
  video: { mode: 'on', size: { width: 1920, height: 1080 } },
}

// Or via Chrome flag (equivalent, browser-wide)
launchOptions: {
  args: ['--force-device-scale-factor=2'],
}

The video file resolution does not change — only the rendered DPI does. If you want a literal 4K file, raise viewport + video.size to 3840×2160 (Knob 2 below).

Knob 2: Native 4K capture

Use only when archival or YouTube hero quality is needed — file size triples vs 1080p HiDPI.

{
  name: 'demo-4k',
  use: {
    viewport: { width: 3840, height: 2160 },
    deviceScaleFactor: 1,                         // already at 4K natively
    video: { mode: 'on', size: { width: 3840, height: 2160 } },
    launchOptions: {
      args: [
        '--enable-features=VaapiVideoEncoder',    // GPU encode where available
        '--disable-gpu-vsync',
      ],
    },
  },
}

Encode hint: convert WebM → AV1 for delivery (-c:v libsvtav1 -crf 32); H.264 at 4K balloons file size.

Knob 3: Anti-aliasing & rendering flags

Stabilize fonts and motion across CI / local / headed / headless.

launchOptions: {
  args: [
    '--force-device-scale-factor=2',             // HiDPI (alt to context option)
    '--font-render-hinting=none',                // platform-consistent font rendering
    '--disable-gpu-vsync',                       // avoid vsync tearing in screencast
    '--disable-features=PaintHolding,LazyFrameLoading', // prevent frame skips
    '--disable-background-timer-throttling',     // smooth animations in headed mode
    '--disable-renderer-backgrounding',
    '--disable-blink-features=AutomationControlled',
  ],
}

Knob 4: Codec & post-encode

# Raise capture-side codec from VP8 → VP9
PLAYWRIGHT_VIDEO_CODEC=vp9 npx playwright test --config=playwright.config.demo.ts

# Post-encode to visually lossless H.264 (CRF 18) for distribution
ffmpeg -i demo.webm -c:v libx264 -preset slow -crf 18 -pix_fmt yuv420p \
  -movflags +faststart -c:a aac -b:a 192k demo.mp4

# Archival AV1 (smaller, slower encode)
ffmpeg -i demo.webm -c:v libsvtav1 -crf 30 -preset 6 -pix_fmt yuv420p10le \
  -c:a libopus demo_av1.mp4

CRF guide: 14 lossless, 18 visually lossless (recommended for masters), 22 standard, 28 aggressive.

Knob 5: page.screencast quality

await page.screencast.start({
  path: 'demo.webm',
  size: { width: 1920, height: 1080 },
  quality: 95,                                    // 1–100 (JPEG-frame quality, default ~80)
});

quality: 90–95 recommended for external demos; below 80 visible compression.

Combined Recipe (recommended default for 2026)

// playwright.config.demo.ts — 1080p HiDPI default
projects: [
  {
    name: 'demo-16x9-hidpi',
    use: {
      viewport: { width: 1920, height: 1080 },
      deviceScaleFactor: 2,
      video: { mode: 'retain-on-failure', size: { width: 1920, height: 1080 } },
      launchOptions: {
        args: [
          '--font-render-hinting=none',
          '--disable-gpu-vsync',
          '--disable-features=PaintHolding',
          '--disable-blink-features=AutomationControlled',
        ],
      },
    },
  },
]

// In-test capture with page.screencast quality=95
const sc = await page.screencast.start({
  path: 'demos/output/feature_16x9_hidpi_20260515.webm',
  size: { width: 1920, height: 1080 },
  quality: 95,
});

Quality vs Cost Matrix

Verification

After capture, verify perceptual quality with reference/demo-quality-metrics.md (VMAF/PSNR/SSIM). HiDPI capture should comfortably clear VMAF ≥ 92 at 1080p.

Caveats

• HiDPI doubles GPU work — verify CI keeps 30 fps. If not, drop deviceScaleFactor to 1 or move CI to a GPU runner.
• --force-device-scale-factor overrides Playwright's deviceScaleFactor context option. Pick one, not both.
• Some sites detect HiDPI and serve @2x images; this is usually what you want for demos, but watch for sites that downscale instead.
• Headless mode with HiDPI rendering can differ slightly from headed; pin channel: 'chrome' or run headed for hero captures.

Video Recording Settings

Video Modes

Prefer page.screencast start/stop inside the test for primary capture. Use recordVideo: 'retain-on-failure' as a debug receipt fallback.

Resolution Settings (1080p is the new baseline)

Codec Selection Matrix (2026)

# Playwright env override
PLAYWRIGHT_VIDEO_CODEC=vp9 npx playwright test --config=playwright.config.demo.ts

# Convert to AV1 (high-compression delivery)
ffmpeg -i demo.webm -c:v libsvtav1 -crf 35 -preset 6 -c:a libopus demo_av1.webm

# Convert to H.264 MP4 (universal)
ffmpeg -i demo.webm -c:v libx264 -preset slow -crf 20 -c:a aac -b:a 192k demo.mp4

HDR / 120fps: Playwright outputs SDR VP8/VP9 only. For HDR10+ or 120fps deliverables, transcode in post (HEVC/AV1) or route the requirement to AI video generators (Sora 2 / Veo 3.1 / Runway Gen-4.5) — Cue cannot produce native HDR from the browser.

page.screencast API Recipes

page.screencast (v1.59 Stable) is the primary recording API. It exposes start/stop, chapter markers, action overlays, custom overlays, and a JPEG-frame callback (onFrame) for Vision streaming.

Methods

Standard Chapter Pattern

const screencast = await page.screencast.start({
  path: 'demos/output/onboard_signup_16x9_20260515.webm',
  size: { width: 1920, height: 1080 },
  quality: 90,
});

await screencast.showActions(); // auto-annotate clicks, fills, navigations

await screencast.showChapter({ title: 'Chapter 1', description: 'Sign up in 30 seconds' });
await page.goto('/signup');
await page.getByLabel('Email').pressSequentially('demo@acme.test', { delay: 80 });

await screencast.showChapter({ title: 'Chapter 2', description: 'Connect your data' });
// ...

await screencast.stop();

Custom Overlay (HTML)

await screencast.showOverlay({
  html: `
    <div style="position:fixed;bottom:48px;left:50%;transform:translateX(-50%);
                background:rgba(0,0,0,0.85);color:#fff;
                padding:16px 32px;border-radius:12px;font:600 24px Inter;">
      ⚡ 5x faster than Excel
    </div>
  `,
  duration: 2500,
});

Multi-Chapter Series (3×45s blueprint)

for (const chapter of chapters) {
  const sc = await page.screencast.start({
    path: `demos/output/${feature}_${chapter.slug}_16x9_20260515.webm`,
    size: { width: 1920, height: 1080 },
  });
  await sc.showChapter({ title: chapter.title });
  await chapter.run(page);
  await sc.stop();
}

Vision-Stream (onFrame)

onFrame(jpegBuffer, timestampMs) fires for each captured frame. Use it to stream live JPEGs to a Vision Model (GPT-4o vision, Claude vision) for "agent watches the screen" loops, live narration, or QA-by-vision.

const screencast = await page.screencast.start({
  path: 'demos/output/agent_session_20260515.webm',
  size: { width: 1280, height: 720 },
  quality: 80,
  onFrame: async (jpeg, ts) => {
    // throttle to ~1 fps for Vision API cost control
    if (ts - lastSent < 1000) return;
    lastSent = ts;
    await visionClient.send({
      image: jpeg.toString('base64'),
      prompt: 'What is the user doing right now? Anything off-screen-worthy?',
    });
  },
});

// agent loop runs as normal Playwright code
await page.goto('/dashboard');
// ...
await screencast.stop();

Cost guard: onFrame fires at ~30 fps. Always throttle (1–4 fps is plenty for narrative agents). Without throttling, a 60s demo = 1,800 Vision calls.

slowMo Configuration Guide

slowMo Values by Use Case

Dynamic slowMo Adjustment

test('demo emphasizing form input', async ({ page }) => {
  // Normal speed for navigation
  await page.goto('/signup');

  // Slow for form input (adjust with manual wait)
  await page.getByLabel('Name').fill('Demo User');
  await page.waitForTimeout(500); // Additional pacing pause

  await page.getByLabel('Email').fill('demo@example.com');
  await page.waitForTimeout(500);

  // Normal speed for button click
  await page.getByRole('button', { name: 'Register' }).click();
});

Output Formats and Conversion

Default Output (WebM)

Playwright natively outputs WebM (VP8). For broader compatibility, convert to MP4 or GIF.

FFmpeg Post-Processing Helper

// demos/helpers/video-convert.ts
import { execSync } from 'child_process';
import path from 'path';

/**
 * Convert WebM to MP4 (H.264) for universal playback
 */
export function convertToMp4(webmPath: string): string {
  const mp4Path = webmPath.replace(/\.webm$/, '.mp4');
  execSync(
    `ffmpeg -i "${webmPath}" -c:v libx264 -preset fast -crf 22 -c:a aac "${mp4Path}" -y`,
    { stdio: 'pipe' }
  );
  return mp4Path;
}

/**
 * Convert WebM to GIF for embedding in docs/README
 */
export function convertToGif(webmPath: string, opts?: { width?: number; fps?: number }): string {
  const { width = 640, fps = 10 } = opts ?? {};
  const gifPath = webmPath.replace(/\.webm$/, '.gif');
  execSync(
    `ffmpeg -i "${webmPath}" -vf "fps=${fps},scale=${width}:-1:flags=lanczos" "${gifPath}" -y`,
    { stdio: 'pipe' }
  );
  return gifPath;
}

Auto-Conversion in afterEach

import { convertToMp4, convertToGif } from '../helpers/video-convert';

test.afterEach(async ({ page }, testInfo) => {
  const video = page.video();
  if (!video) return;

  const date = new Date().toISOString().slice(0, 10).replace(/-/g, '');
  const baseName = `${testInfo.title.replace(/\s+/g, '_')}_${date}`;
  const webmPath = `demos/output/${baseName}.webm`;

  await video.saveAs(webmPath);

  // Generate MP4 for Slack/email/presentations
  convertToMp4(webmPath);

  // Generate GIF for README/docs (optional)
  // convertToGif(webmPath, { width: 800, fps: 12 });

  await testInfo.attach('demo-video', { path: webmPath, contentType: 'video/webm' });
});

Format Selection Guide

Output File Naming Conventions

Naming encodes feature, action, aspect, and date for fast filtering and CDN routing.

Environment Variables

# .env.demo
DEMO_BASE_URL=http://localhost:3000
DEMO_USER_EMAIL=demo@example.com
DEMO_USER_PASSWORD=DemoPass123

// playwright.config.demo.ts
import dotenv from 'dotenv';
dotenv.config({ path: '.env.demo' });

export default defineConfig({
  use: {
    baseURL: process.env.DEMO_BASE_URL,
  },
});

CI/CD Configuration

Demo Recording with GitHub Actions

# .github/workflows/demo-recording.yml
name: Record Demo Videos

on:
  workflow_dispatch:
    inputs:
      feature:
        description: 'Feature to demo'
        required: true
        default: 'all'

jobs:
  record:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
          node-version: 20
      - run: npm ci
      - run: npx playwright install --with-deps chromium
      - name: Record demos
        run: npx playwright test --config=playwright.config.demo.ts
      - name: Convert to MP4
        run: |
          sudo apt-get install -y ffmpeg
          for f in demos/output/*.webm; do
            ffmpeg -i "$f" -c:v libx264 -preset fast -crf 22 "${f%.webm}.mp4" -y
          done
      - uses: actions/upload-artifact@v4
        with:
          name: demo-videos
          path: |
            demos/output/*.webm
            demos/output/*.mp4

Directory Structure

demos/
├── specs/           # Demo test files
├── helpers/         # Helper functions (overlay, auth, data, video-convert)
├── fixtures/        # Test data, images
├── output/          # Generated videos (WebM + MP4 + GIF)
└── report/          # HTML reports

Browser Engine Notes

Chrome for Testing (v1.57+)

Since Playwright 1.57, demos use Chrome for Testing builds instead of vanilla Chromium.

Chrome for Testing may render fonts and anti-aliasing slightly differently from Chromium. When upgrading Playwright across major versions, re-check overlay text clarity, brand colors, and icon crispness on existing demos.

Pin a specific channel only when reproducibility or CI memory footprint is critical:

use: {
  channel: 'chromium', // fall back to legacy Chromium build
}

browser.bind() for Shared Sessions (v1.59 Stable)

browser.bind() exposes a launched browser instance over WebSocket to @playwright/cli, @playwright/mcp, and other clients simultaneously. Use this when the demo script and an agentic receipt client (or a Claude/Cursor MCP loop) should share one browser — avoids launching duplicate Chromes and doubling memory.

const browser = await chromium.launch({ headless: false });
const ws = await browser.bind({ port: 9222 }); // share with CLI/MCP clients
console.log('Bound at', ws.wsEndpoint());
// demo flow runs here; CLI / MCP clients can attach in parallel

Inspect all bound browsers with:

npx @playwright/cli show   # dashboard UI listing bound sessions

Typical scenarios:

• A CI job runs a feature flow while Claude (via MCP) annotates / narrates the same session.
• A Cue recording shares the browser with @playwright/cli for trace export.
• A Vision-loop agent (onFrame consumer) watches the screen while the demo executes.

Incremental Snapshot Mode (v1.59 default)

v1.59 ships incremental snapshot as the default snapshot mode. Long Playwright sessions used to re-send full DOM snapshots per step, ballooning token usage in agentic pipelines. Now only deltas are sent. No config change needed; benefit is automatic in 1.59+. For Cue's agentic_video_receipts capability this reduces per-step token cost noticeably in 30+ step flows.

Playwright MCP vs CLI for Agentic Recording

When agents produce video receipts of automated work, choose the transport based on environment and workload shape.

Decision Matrix

Decision Shortcut

• Agent has filesystem access → CLI.
• Sandboxed environment → MCP.
• Step count > 10 sequential interactions → CLI (token accumulation compounds per step in MCP).

Microsoft's public guidance (early 2026) recommends CLI for coding agents and reserves MCP for exploratory / autonomous workflows.

Troubleshooting

Critical Constraints (full table)

Canonical home for the constraint table summarized in SKILL.md. Each row's own reference holds the implementation detail.

Decision-level thresholds. Implementation detail and rationale live in references.