aidemo — your coding agent makes the demo video

aidemo.top · watch a real 51s output ▶ · authoring guide · render in CI

Tell your coding agent "record a 45s demo of the checkout flow" — get back a polished MP4 with voiceover, synced captions, and auto-zoom. Any MCP-capable agent (Claude Code, Codex CLI, Gemini CLI) writes one storyboard.json; the headless engine drives a real Chrome, records a deterministic replay, voices it, captions it, and trims the dead time. Because the replay is deterministic, the demo re-renders itself in CI when the product changes — no re-recording, no API key, about $0 a render. An open-source (MIT) alternative to Screen Studio, Clueso, or Demosmith for when you'd rather your coding agent make the demo.

Install: Claude Code /plugin marketplace add tandryukha/aidemo · CI uses: tandryukha/aidemo@stable · CLI npx -y @tandryukha/aidemo · Homebrew brew install tandryukha/aidemo/aidemo Published on the GitHub Marketplace, npm, a Homebrew tap, and the MCP Registry.

Real output — a ~51 s self-narrated tour of Wikipedia (portal search → Ada Lovelace → focus-zoom → click through to the Analytical Engine → glide scroll), authored by Claude from one storyboard.json and recorded as a deterministic replay. The preview GIF is silent; watch the full version with narration ▶.

Three ways to use it

1. From your coding agent — the fastest path. In Claude Code: /plugin marketplace add tandryukha/aidemo then /plugin install record-demo@aidemo (bundles the skill and the MCP server). In Codex / Gemini / any MCP agent: npx -y github:tandryukha/aidemo#stable repo-init. Then just say "record a 45s demo of <flow>" and the agent authors + renders it.

2. Locally, free & offline — AIDEMO_TTS_PROVIDER=local aidemo render <dir> --headless. An in-process voice model + script-timed captions mean no API key, ~$0, fully offline. See docs/LOCAL_MODELS.md.

3. In CI, self-maintaining — drop uses: tandryukha/aidemo@stable into a workflow. When the product changes, it replays the committed storyboard and commits fresh media — no key, no LLM tokens, ~$0 on free runner minutes. See docs/CI.md.

Free & open source. MIT-licensed. Runs on GitHub's free Actions tier, or fully local at $0 with the in-process voice — no API key, no cloud upload, no telemetry. Works against localhost and auth-walled apps (your own Chrome).

Related MCP server: ittybitty MCP server

From one sentence to a narrated MP4

You type a sentence, the agent writes an artifact you can read and edit, the engine records and cuts it:

1 · What you type — one line to any MCP-capable agent (Claude Code here):

claude "record a 45s demo touring Wikipedia: search for Ada Lovelace,
open the Analytical Engine, then glide down the article"

2 · What the agent authors — a plain, editable storyboard.json (excerpt: narration + a fixed browser action-spec, side by side — no generated code):

{
  "title": "A quick tour of Wikipedia",
  "zoom": {},                                  // Screen-Studio-style auto-zoom
  "scenes": [
    { "id": "search",
      "narration": "Start at the Wikipedia portal and search for Ada Lovelace.",
      "actions": [
        { "op": "goto", "url": "https://www.wikipedia.org/" },
        { "op": "type", "target": { "selector": "#searchInput" }, "text": "Ada Lovelace" },
        { "op": "click", "target": { "selector": "button[type=submit]" } } ] },
    { "id": "engine",
      "narration": "Her notes on Babbage's Analytical Engine hold the first computer program.",
      "actions": [
        { "op": "focus", "target": { "selector": "#firstHeading" } },
        { "op": "click", "target": { "selector": "a[href*='Analytical_Engine']" } },
        { "op": "scrollBy", "dy": 900, "easing": "glide" } ] }
  ]
}

3 · How it's recorded + cut — aidemo render drives a real Chrome (smooth animated cursor, human-cadence typing, auto-zoom), then trims the dead time and syncs to the narration:

storyboard.json
   → voice     OpenAI / ElevenLabs / local TTS → audio/narration.mp3 + voice.json
   → record    drives Chrome, animated cursor  → recordings/raw.{webm,mp4} + timeline.json
   → captions  Whisper word timestamps         → generated/captions.{srt,vtt,cues.json}
   → compose   trim idle · sync · auto-zoom · cards · caption · mux → output/final-demo.mp4

4 · What you get — output/final-demo.mp4, plus a README-ready GIF (aidemo gif) and named stills (aidemo stills) from the same take. UI changed? Re-run against the same storyboard — no re-recording by hand.

The design goal: demos that look human-made and snappy, not like an AI clicking around and waiting between screenshots — by separating authoring (slow, one-time — figure out the flow) from recording (a fast deterministic replay with a smooth animated cursor).

What teams render with it

• GitHub README demos — aidemo gif demos/onboarding, drop the autoplaying GIF into the readme (the GIFs on this page are exactly that).

• Landing-page hero videos — the muted-autoplay MP4 on aidemo.top is a rendered demo, poster frame and all.

• Release / what-shipped demos — narrate the new feature, then gh release upload v1.4.0 demos/whats-new/output/final-demo.mp4.

• Customer & prospect demos — personalized flows against your real app: localhost, auth walls, your own logged-in Chrome; nothing leaves the machine.

Render in CI (self-maintaining demos)

Commit a storyboard and the aidemo GitHub Action keeps its demo media in sync — a fresh narrated, captioned MP4 (and GIF) on every relevant change. Deterministic replay + a local voice mean no API key, no LLM tokens, about $0 (just free runner minutes). It's the loop a screen recorder can't run: your demo maintains itself.

# .github/workflows/demo.yml
- uses: actions/checkout@v4
- run: sudo apt-get update && sudo apt-get install -y ffmpeg   # ubuntu ships Chrome, not ffmpeg
- uses: tandryukha/aidemo@stable
  with:
    demos: demos/*
    tts: local        # in-process voice → no keys, no tokens
    gif: "true"

Full recipe, templates (auto-commit / PR-comment / cron-refresh), and the always-fresh-embeds trick: docs/CI.md, docs/EMBEDS.md, docs/recipes/.

Quick start (self-contained smoke test)

A bundled fixture store (search → results → cart → checkout) that renders a finished demo with zero external dependencies:

npm install                                # Node 20+, system Chrome, ffmpeg on PATH
node examples/local-demo/serve.mjs         # terminal 1: fixture on :8787
node bin/aidemo.mjs render examples/local-demo --headless   # terminal 2
open examples/local-demo/output/final-demo.mp4   # xdg-open on Linux, start on Windows

Voice/captions need OPENAI_API_KEY in .env — or AIDEMO_TTS_PROVIDER=local (no key, offline), or OPENAI_BASE_URL at a local server. See docs/LOCAL_MODELS.md. No Playwright browser download is needed — the engine uses your system Chrome (channel: "chrome").

The bundled fixture rendered end-to-end — narrated, captioned, auto-trimmed. Silent preview; full version ▶.

CLI

Each step is independently runnable and re-runnable — regenerate voice without re-recording, recompose without re-transcribing, etc.

aidemo init <name>            # scaffold demos/<name>/ with a starter storyboard
aidemo voice   <dir>          # per-scene TTS → narration.mp3 + voice.json
aidemo record  <dir>          # drive Chrome → raw video + timeline.json
aidemo probe   <dir>          # record-only dry run (verify selectors), no key needed
aidemo captions <dir>         # Whisper → captions.{srt,vtt,cues.json} (--offline for no network)
aidemo compose <dir>          # trim + sync + zoom + cards + caption + mux → final-demo.mp4
aidemo gif     <dir>          # final-demo.mp4 → README-ready GIF (autoplays on GitHub)
aidemo render  <dir>          # voice → record → captions → compose
aidemo guide                  # print the canonical authoring guide
aidemo doctor                 # check Node, ffmpeg, Chrome, voice endpoint

Add --headless for CI/fixtures; omit it for real sites that need your logged-in session. --profile <dir> picks the Chrome user-data dir; --capture native|obs switches to high-fidelity screen capture. voice/render skip TTS for unchanged scenes, and record salvages a failed take (keeps the footage + drops a screenshot/frame-dump in logs/).

Agent interface (MCP)

aidemo mcp runs a stdio MCP server (no network listener) exposing the engine to any MCP client. The Claude Code plugin bundles it; aidemo repo-init registers it agent-neutrally (.mcp.json for Claude Code, .gemini/settings.json for Gemini; codex mcp add aidemo -- npx -y github:tandryukha/aidemo#stable mcp for Codex).

• Authoring tools — get_authoring_guide serves docs/AUTHORING.md version-matched from the engine (can't go stale); get_storyboard_schema, validate_storyboard, init_demo, doctor.

• Pipeline tools run as jobs — probe/record/render/voice/captions/ compose/gif return a jobId immediately; job_status reports stage, per-scene progress, and (on failure) the screenshot/frame-dump paths.

Why it's built this way

• Deterministic replay, not an LLM in the loop. The recording runs a fixed action-spec at full speed, so the video is smooth. The agent only authors the storyboard (and confirms selectors once), never during capture.

• Declarative action-spec + fixed player (not generated spec.ts). Safer, editable, and it emits a timeline for free — compose fits each scene's video to its narration by trimming/speeding only the idle parts, freeze-holding a static page for any remainder instead of ugly slow-motion.

• Captions via overlaid PNGs, not libass. Many ffmpeg builds lack subtitles/drawtext; aidemo rasterizes each caption with headless Chrome and overlays it with time-gated enable — works on any ffmpeg with overlay.

• Cinematic polish is compose-time, not record-time — a bad zoom is a recompose, never a re-record. See docs/POLISH.md.

Deeper docs

• docs/AUTHORING.md — the canonical storyboard schema, action vocabulary, and demo-director principles (served by the engine).

• docs/LOCAL_MODELS.md — no-key rendering: in-process Kokoro voice, local speech servers (speaches), ElevenLabs, offline captions.

• docs/POLISH.md — auto-zoom, scroll easing, music ducking, intro/outro cards, motion blur, cursor control, native/OBS high-fidelity capture.

• docs/CHATGPT_APPS.md — recording ChatGPT Apps SDK widgets (dedicated profile, nested iframes, waitForWidget).

• docs/CI.md · docs/EMBEDS.md · docs/recipes/ — CI rendering, always-fresh embeds, agent-in-CI recipes.

Setup

Prereqs: Node 20+, Google Chrome, ffmpeg + ffprobe on PATH. Developed and tested on macOS; Linux works for the default (Playwright) capture and --capture obs. Run aidemo doctor to check your setup.

npm install
cp .env.example .env      # add OPENAI_API_KEY, or use AIDEMO_TTS_PROVIDER=local (no key)

Project layout (per demo)

demos/<name>/          ← your working area (untracked; scaffold with `aidemo init`)
  input/      brief.md
  generated/  storyboard.json  timeline.json  captions.{srt,vtt,cues.json}
  recordings/ raw.webm (or raw.mp4 for native/OBS capture)
  audio/      scene-*.mp3  narration.mp3  voice.json
  output/     final-demo.mp4
  logs/       <command>.log  fail-<scene>-<n>.{png,json} (on a failed action)

Security & trust

• No telemetry, no analytics, no install-time scripts (package.json has no postinstall/preinstall).

• Network is user-initiated only: api.openai.com (only voice/captions, your key — or a local server via OPENAI_BASE_URL), api.elevenlabs.io (opt-in), huggingface.co (download-only, once, for AIDEMO_TTS_PROVIDER=local), and github.com (your own gh, for aidemo feedback). Recording/composing are fully local. The MCP server is stdio-only — no listener.

• Small, auditable surface: ~20 source files, 7 runtime deps, MIT. Pin an immutable ref if you're wary of the moving #stable tag: npx -y github:tandryukha/aidemo#v0.8.0.

• Full detail: docs/LOCAL_MODELS.md · report vulnerabilities privately per SECURITY.md.

Roadmap

• Comments on the video (pause & comment) and in-place transcript editing: captions map to scenes, so editing a line marks that scene dirty and aidemo voice --scene <id> + compose regenerates only the delta.

• Web UI, project history, brand kits, changelog integrations.

• Hosted public MCP (see docs/plans/public-mcp.md).

Shipped: the GitHub Action (CI re-render), cinematic polish (auto-zoom, scroll easing, music ducking, intro/outro cards, motion blur, post-hoc cursor control), native/OBS capture, the agent-neutral MCP server + authoring guide, ElevenLabs and in-process local voice providers, and the Claude Code plugin.

Contributing

Issues and PRs welcome — see CONTRIBUTING.md for dev setup, the smoke test, and the DCO sign-off requirement. Recording-session feedback has a fast path: aidemo feedback demos/<name> pre-fills a structured issue.

License

MIT © Andrii Taran