Official agent skill

UI Demo

by sanity-io in sanity-io/ui

Record polished UI demo videos using Playwright. An agent skill from sanity-io/ui.

OfficialMITAuto-check passedTesting & QA

Install UI Demo

skills CLI
$ npx skills add sanity-io/ui --skill ui-demo -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI
$ gh skill install sanity-io/ui ui-demo --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy
$ git clone --depth 1 https://github.com/sanity-io/ui.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.agents/skills/ui-demo .claude/skills/ui-demo && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Facts

Skill name
ui-demo
GitHub stars
176
Used in
4 other repos
Token cost
~3.8k tokens
SKILL.md length
785 words
Files
1
Skills in repo
5
Repo updated
First seen
Licence
MIT

At a glance

Record polished UI demo videos using Playwright. An agent skill from sanity-io/ui.

  • Works in 3 steps: Discover → Rehearse → Record
  • The user asks to create a demo
  • SKILL.md covers When to Use, Three-Phase Process, Phase 1: Discover and Phase 2: Rehearse, plus 4 more sections
  • Calls node; reaches w3.org

What it does

UI Demo is an agent skill from sanity-io/ui, published by the product's own GitHub organization. Record polished UI demo videos using Playwright. Use when the user asks to create a demo, walkthrough, screen recording, or tutorial video of a web application. Produces WebM videos with visible cursor, natural pacing, and professional feel.

Its SKILL.md is about 3.8k tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.

It sits in Testing & QA, covering Video production and Browser testing. It works with Playwright. The repository describes itself as: The Sanity UI design system. The licence is MIT.

When your agent uses it

  • The user asks to create a demo
  • Screen recording
  • Tutorial video of a web application

Example prompts

  • “/ui-demo”

Workflow steps

3 steps, taken from the step headings in SKILL.md.

  1. Discover
  2. Rehearse
  3. Record

What it can do on your machine

Read from SKILL.md and the folder at commit bcd7416. It shows what the files ask for, not the result of running them.

  • Tool permissions

    Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

    From allowed-tools in the SKILL.md frontmatter.

  • Runs code

    Shell commands in SKILL.md call:

    • node

    From the folder's file list and the shell code blocks in SKILL.md.

  • Network

    Hosts in commands or code, which the agent is likely to contact:

    • w3.org

    From URLs in SKILL.md, links to its own repository left out.

  • Credentials

    Names no API keys, tokens, secrets or passwords.

    From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

UI Demo loads about 3.8k tokens when it runs. Until then it costs about 62 tokens; SKILL.md has 785 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it
~62
When it runs · the whole SKILL.md, loaded when a task matches
~3.8k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from sanity-io/ui at commit bcd7416, republished under its MIT licence (© sanity-io). 785 words, ~3,781 tokens.

Download SKILL.mdSave it as .claude/skills/ui-demo/SKILL.md (or your agent's skills folder).
name
ui-demo
description
Record polished UI demo videos using Playwright. Use when the user asks to create a demo, walkthrough, screen recording, or tutorial video of a web application. Produces WebM videos with visible cursor, natural pacing, and professional feel.
metadata.origin
ECC

UI Demo Video Recorder

Record polished demo videos of web applications using Playwright's video recording with an injected cursor overlay, natural pacing, and storytelling flow.

When to Use

  • User asks for a "demo video", "screen recording", "walkthrough", or "tutorial"
  • User wants to showcase a feature or workflow visually
  • User needs a video for documentation, onboarding, or stakeholder presentation

Three-Phase Process

Every demo goes through three phases: Discover -> Rehearse -> Record. Never skip straight to recording.


Phase 1: Discover

Before writing any script, explore the target pages to understand what is actually there.

Why

You cannot script what you have not seen. Fields may be <input> not <textarea>, dropdowns may be custom components not <select>, and comment boxes may support @mentions or #tags. Assumptions break recordings silently.

How

Navigate to each page in the flow and dump its interactive elements:

javascript
// Run this for each page in the flow BEFORE writing the demo script
const fields = await page.evaluate(() => {
  const els = []
  document.querySelectorAll('input, select, textarea, button, [contenteditable]').forEach((el) => {
    if (el.offsetParent !== null) {
      els.push({
        tag: el.tagName,
        type: el.type || '',
        name: el.name || '',
        placeholder: el.placeholder || '',
        text: el.textContent?.trim().substring(0, 40) || '',
        contentEditable: el.contentEditable === 'true',
        role: el.getAttribute('role') || '',
      })
    }
  })
  return els
})
console.log(JSON.stringify(fields, null, 2))
What to look for
  • Form fields: Are they <select>, <input>, custom dropdowns, or comboboxes?
  • Select options: Dump option values AND text. Placeholders often have value="0" or value="" which looks non-empty. Use Array.from(el.options).map(o => ({ value: o.value, text: o.text })). Skip options where text includes "Select" or value is "0".
  • Rich text: Does the comment box support @mentions, #tags, markdown, or emoji? Check placeholder text.
  • Required fields: Which fields block form submission? Check required, * in labels, and try submitting empty to see validation errors.
  • Dynamic content: Do fields appear after other fields are filled?
  • Button labels: Exact text such as "Submit", "Submit Request", or "Send".
  • Table column headers: For table-driven modals, map each input[type="number"] to its column header instead of assuming all numeric inputs mean the same thing.
Output

A field map for each page, used to write correct selectors in the script. Example:

text
/purchase-requests/new:
  - Budget Code: <select> (first select on page, 4 options)
  - Desired Delivery: <input type="date">
  - Context: <textarea> (not input)
  - BOM table: inline-editable cells with span.cursor-pointer -> input pattern
  - Submit: <button> text="Submit"

/purchase-requests/N (detail):
  - Comment: <input placeholder="Type a message..."> supports @user and #PR tags
  - Send: <button> text="Send" (disabled until input has content)

Phase 2: Rehearse

Run through all steps without recording. Verify every selector resolves.

Why

Silent selector failures are the main reason demo recordings break. Rehearsal catches them before you waste a recording.

How

Use ensureVisible, a wrapper that logs and fails loudly:

javascript
async function ensureVisible(page, locator, label) {
  const el = typeof locator === 'string' ? page.locator(locator).first() : locator
  const visible = await el.isVisible().catch(() => false)
  if (!visible) {
    const msg = `REHEARSAL FAIL: "${label}" not found - selector: ${typeof locator === 'string' ? locator : '(locator object)'}`
    console.error(msg)
    const found = await page.evaluate(() => {
      return Array.from(document.querySelectorAll('button, input, select, textarea, a'))
        .filter((el) => el.offsetParent !== null)
        .map((el) => `${el.tagName}[${el.type || ''}] "${el.textContent?.trim().substring(0, 30)}"`)
        .join('\n  ')
    })
    console.error('  Visible elements:\n  ' + found)
    return false
  }
  console.log(`REHEARSAL OK: "${label}"`)
  return true
}
Rehearsal script structure
javascript
const steps = [
  {label: 'Login email field', selector: '#email'},
  {label: 'Login submit', selector: 'button[type="submit"]'},
  {label: 'New Request button', selector: 'button:has-text("New Request")'},
  {label: 'Budget Code select', selector: 'select'},
  {label: 'Delivery date', selector: 'input[type="date"]:visible'},
  {label: 'Description field', selector: 'textarea:visible'},
  {label: 'Add Item button', selector: 'button:has-text("Add Item")'},
  {label: 'Submit button', selector: 'button:has-text("Submit")'},
]

let allOk = true
for (const step of steps) {
  if (!(await ensureVisible(page, step.selector, step.label))) {
    allOk = false
  }
}
if (!allOk) {
  console.error('REHEARSAL FAILED - fix selectors before recording')
  process.exit(1)
}
console.log('REHEARSAL PASSED - all selectors verified')
When rehearsal fails
  1. Read the visible-element dump.
  2. Find the correct selector.
  3. Update the script.
  4. Re-run rehearsal.
  5. Only proceed when every selector passes.

Phase 3: Record

Only after discovery and rehearsal pass should you create the recording.

Recording Principles
1. Storytelling Flow

Plan the video as a story. Follow user-specified order, or use this default:

  • Entry: Login or navigate to the starting point
  • Context: Pan the surroundings so viewers orient themselves
  • Action: Perform the main workflow steps
  • Variation: Show a secondary feature such as settings, theme, or localization
  • Result: Show the outcome, confirmation, or new state
2. Pacing
  • After login: 4s
  • After navigation: 3s
  • After clicking a button: 2s
  • Between major steps: 1.5-2s
  • After the final action: 3s
  • Typing delay: 25-40ms per character
3. Cursor Overlay

Inject an SVG arrow cursor that follows mouse movements:

javascript
async function injectCursor(page) {
  await page.evaluate(() => {
    if (document.getElementById('demo-cursor')) return
    const cursor = document.createElement('div')
    cursor.id = 'demo-cursor'
    cursor.innerHTML = `<svg width="24" height="24" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg">
      <path d="M5 3L19 12L12 13L9 20L5 3Z" fill="white" stroke="black" stroke-width="1.5" stroke-linejoin="round"/>
    </svg>`
    cursor.style.cssText = `
      position: fixed; z-index: 999999; pointer-events: none;
      width: 24px; height: 24px;
      transition: left 0.1s, top 0.1s;
      filter: drop-shadow(1px 1px 2px rgba(0,0,0,0.3));
    `
    cursor.style.left = '0px'
    cursor.style.top = '0px'
    document.body.appendChild(cursor)
    document.addEventListener('mousemove', (e) => {
      cursor.style.left = e.clientX + 'px'
      cursor.style.top = e.clientY + 'px'
    })
  })
}

Call injectCursor(page) after every page navigation because the overlay is destroyed on navigate.

Show full SKILL.md (310 more words)Show less
4. Mouse Movement

Never teleport the cursor. Move to the target before clicking:

javascript
async function moveAndClick(page, locator, label, opts = {}) {
  const {postClickDelay = 800, ...clickOpts} = opts
  const el = typeof locator === 'string' ? page.locator(locator).first() : locator
  const visible = await el.isVisible().catch(() => false)
  if (!visible) {
    console.error(`WARNING: moveAndClick skipped - "${label}" not visible`)
    return false
  }
  try {
    await el.scrollIntoViewIfNeeded()
    await page.waitForTimeout(300)
    const box = await el.boundingBox()
    if (box) {
      await page.mouse.move(box.x + box.width / 2, box.y + box.height / 2, {steps: 10})
      await page.waitForTimeout(400)
    }
    await el.click(clickOpts)
  } catch (e) {
    console.error(`WARNING: moveAndClick failed on "${label}": ${e.message}`)
    return false
  }
  await page.waitForTimeout(postClickDelay)
  return true
}

Every call should include a descriptive label for debugging.

5. Typing

Type visibly, not instant-fill:

javascript
async function typeSlowly(page, locator, text, label, charDelay = 35) {
  const el = typeof locator === 'string' ? page.locator(locator).first() : locator
  const visible = await el.isVisible().catch(() => false)
  if (!visible) {
    console.error(`WARNING: typeSlowly skipped - "${label}" not visible`)
    return false
  }
  await moveAndClick(page, el, label)
  await el.fill('')
  await el.pressSequentially(text, {delay: charDelay})
  await page.waitForTimeout(500)
  return true
}
6. Scrolling

Use smooth scroll instead of jumps:

javascript
await page.evaluate(() => window.scrollTo({top: 400, behavior: 'smooth'}))
await page.waitForTimeout(1500)
7. Dashboard Panning

When showing a dashboard or overview page, move the cursor across key elements:

javascript
async function panElements(page, selector, maxCount = 6) {
  const elements = await page.locator(selector).all()
  for (let i = 0; i < Math.min(elements.length, maxCount); i++) {
    try {
      const box = await elements[i].boundingBox()
      if (box && box.y < 700) {
        await page.mouse.move(box.x + box.width / 2, box.y + box.height / 2, {steps: 8})
        await page.waitForTimeout(600)
      }
    } catch (e) {
      console.warn(
        `WARNING: panElements skipped element ${i} (selector: "${selector}"): ${e.message}`,
      )
    }
  }
}
8. Subtitles

Inject a subtitle bar at the bottom of the viewport:

javascript
async function injectSubtitleBar(page) {
  await page.evaluate(() => {
    if (document.getElementById('demo-subtitle')) return
    const bar = document.createElement('div')
    bar.id = 'demo-subtitle'
    bar.style.cssText = `
      position: fixed; bottom: 0; left: 0; right: 0; z-index: 999998;
      text-align: center; padding: 12px 24px;
      background: rgba(0, 0, 0, 0.75);
      color: white; font-family: -apple-system, "Segoe UI", sans-serif;
      font-size: 16px; font-weight: 500; letter-spacing: 0.3px;
      transition: opacity 0.3s;
      pointer-events: none;
    `
    bar.textContent = ''
    bar.style.opacity = '0'
    document.body.appendChild(bar)
  })
}

async function showSubtitle(page, text) {
  await page.evaluate((t) => {
    const bar = document.getElementById('demo-subtitle')
    if (!bar) return
    if (t) {
      bar.textContent = t
      bar.style.opacity = '1'
    } else {
      bar.style.opacity = '0'
    }
  }, text)
  if (text) await page.waitForTimeout(800)
}

Call injectSubtitleBar(page) alongside injectCursor(page) after every navigation.

Usage pattern:

javascript
await showSubtitle(page, 'Step 1 - Logging in')
await showSubtitle(page, 'Step 2 - Dashboard overview')
await showSubtitle(page, '')

Guidelines:

  • Keep subtitle text short, ideally under 60 characters.
  • Use Step N - Action format for consistency.
  • Clear the subtitle during long pauses where the UI can speak for itself.

Script Template

javascript
'use strict'
const {chromium} = require('playwright')
const path = require('path')
const fs = require('fs')

const BASE_URL = process.env.QA_BASE_URL || 'http://localhost:3000'
const VIDEO_DIR = path.join(__dirname, 'screenshots')
const OUTPUT_NAME = 'demo-FEATURE.webm'
const REHEARSAL = process.argv.includes('--rehearse')

// Paste injectCursor, injectSubtitleBar, showSubtitle, moveAndClick,
// typeSlowly, ensureVisible, and panElements here.

;(async () => {
  const browser = await chromium.launch({headless: true})

  if (REHEARSAL) {
    const context = await browser.newContext({viewport: {width: 1280, height: 720}})
    const page = await context.newPage()
    // Navigate through the flow and run ensureVisible for each selector.
    await browser.close()
    return
  }

  const context = await browser.newContext({
    recordVideo: {dir: VIDEO_DIR, size: {width: 1280, height: 720}},
    viewport: {width: 1280, height: 720},
  })
  const page = await context.newPage()

  try {
    await injectCursor(page)
    await injectSubtitleBar(page)

    await showSubtitle(page, 'Step 1 - Logging in')
    // login actions

    await page.goto(`${BASE_URL}/dashboard`)
    await injectCursor(page)
    await injectSubtitleBar(page)
    await showSubtitle(page, 'Step 2 - Dashboard overview')
    // pan dashboard

    await showSubtitle(page, 'Step 3 - Main workflow')
    // action sequence

    await showSubtitle(page, 'Step 4 - Result')
    // final reveal
    await showSubtitle(page, '')
  } catch (err) {
    console.error('DEMO ERROR:', err.message)
  } finally {
    await context.close()
    const video = page.video()
    if (video) {
      const src = await video.path()
      const dest = path.join(VIDEO_DIR, OUTPUT_NAME)
      try {
        fs.copyFileSync(src, dest)
        console.log('Video saved:', dest)
      } catch (e) {
        console.error('ERROR: Failed to copy video:', e.message)
        console.error('  Source:', src)
        console.error('  Destination:', dest)
      }
    }
    await browser.close()
  }
})()

Usage:

bash
# Phase 2: Rehearse
node demo-script.cjs --rehearse

# Phase 3: Record
node demo-script.cjs

Checklist Before Recording

  • Discovery phase completed
  • Rehearsal passes with all selectors OK
  • Headless mode enabled
  • Resolution set to 1280x720
  • Cursor and subtitle overlays re-injected after every navigation
  • showSubtitle(page, 'Step N - ...') used at major transitions
  • moveAndClick used for all clicks with descriptive labels
  • typeSlowly used for visible input
  • No silent catches; helpers log warnings
  • Smooth scrolling used for content reveal
  • Key pauses are visible to a human viewer
  • Flow matches the requested story order
  • Script reflects the actual UI discovered in phase 1

Common Pitfalls

  1. Cursor disappears after navigation - re-inject it.
  2. Video is too fast - add pauses.
  3. Cursor is a dot instead of an arrow - use the SVG overlay.
  4. Cursor teleports - move before clicking.
  5. Select dropdowns look wrong - show the move, then pick the option.
  6. Modals feel abrupt - add a read pause before confirming.
  7. Video file path is random - copy it to a stable output name.
  8. Selector failures are swallowed - never use silent catch blocks.
  9. Field types were assumed - discover them first.
  10. Features were assumed - inspect the actual UI before scripting.
  11. Placeholder select values look real - watch for "0" and "Select...".
  12. Popups create separate videos - capture popup pages explicitly and merge later if needed.

© sanity-io, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

Just SKILL.md in .agents/skills/ui-demo of sanity-io/ui.

Open the folder on GitHubat commit bcd7416

Used in 4 other repositories

We found 4 copies of this SKILL.md (exact, near-identical or edited) in other folders, from 4 other GitHub owners. This page covers the copy in sanity-io/ui, which our catalogue first saw on October 7, 2026.

Compare with similar skills

UI Demo next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

UI Demo compared with similar skills
SkillStarsUsed inTokensAuto-checkLicenceRepo updated
UI Demo this skillsanity-io/ui1764 repos~3.8kAutomated safety check: PassMIT
Demo Videohmislk/hmis236—~3.9kAutomated safety check: PassGPL-3.0
Record E2E Giflablup/backend.ai-webui133—~907Automated safety check: NotesLGPL-3.0
Playwright Browser Demo Recordingdigitalsamba/claude-code-video-toolkit2.2k1 repos~3.2kAutomated safety check: PassMIT
Mobius Self Evo Demomobius-system/mobius139—~3.8kAutomated safety check: PassCustom licence
Michel UI Demo RecorderPackmindHub/packmind318—~6.4kAutomated safety check: PassApache-2.0

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Works with

Questions about UI Demo

What does UI Demo do?

Record polished UI demo videos using Playwright. An agent skill from sanity-io/ui. UI Demo is an agent skill from sanity-io/ui, published by the product's own GitHub organization. Record polished UI demo videos using Playwright.

When should I use UI Demo?

UI Demo fits situations like: the user asks to create a demo; screen recording; tutorial video of a web application.

How do I install UI Demo in Claude Code?

Run `npx skills add sanity-io/ui --skill ui-demo -a claude-code`. Or copy the skill folder (.agents/skills/ui-demo in sanity-io/ui) into .claude/skills/ui-demo in your project. Claude Code loads it when a task matches its description.

How do I install UI Demo in Codex?

Run `npx skills add sanity-io/ui --skill ui-demo -a codex`. Or copy the skill folder (.agents/skills/ui-demo in sanity-io/ui) into .agents/skills/ui-demo in your project. Codex loads it when a task matches its description.

Can I use UI Demo in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add sanity-io/ui --skill ui-demo -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/ui-demo, .gemini/skills/ui-demo, .github/skills/ui-demo and .opencode/skills/ui-demo in your project.

What does UI Demo need to run?

Going by SKILL.md and its folder, UI Demo needs the command-line tools its instructions call (node).

Does UI Demo access the network?

SKILL.md names 1 domain. In commands or code: w3.org; the agent is likely to contact it when it follows the instructions. This is read from the text; nothing was executed.

Is UI Demo safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does UI Demo use?

UI Demo is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does UI Demo use?

About 3.8k tokens (SKILL.md is roughly 15k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.

What are the alternatives to UI Demo?

Skills that share tags, products or a category with UI Demo: Demo Video (hmislk/hmis, 236 stars), Record E2E Gif (lablup/backend.ai-webui, 133 stars), Playwright Browser Demo Recording (digitalsamba/claude-code-video-toolkit, 2.2k stars) and Mobius Self Evo Demo (mobius-system/mobius, 139 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains UI Demo?

sanity-io (a GitHub organization, an official publisher) maintains it in sanity-io/ui, which has 176 GitHub stars. The repository holds 5 skills in this directory. The repository was last updated on October 9, 2026.

Source: sanity-io/ui on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.