GitHub - mrieck/demoday-claude-plugin: Claude Code plugin that creates demo videos for your projects. Claude is given tools to drive the browser/cli, make recordings, and uses FAL.ai, ElevenLabs, and remotion to build a demo video with scene transitions.

Your software deserves a launch video. Let Claude film it.

DemoDay is a Claude Code plugin that turns any codebase into a finished, narrated demo video. Claude reads your repo, writes the script with you, drives your app on screen, narrates it with an AI voiceover — and hands you a polished MP4 with intro, captions, transitions and an optional on-camera presenter. One command, about the cost of a coffee. macOS only.

/demoday:create-demo-video

🎬 See it in action

Sample demo video of Overboard, another Claude Plugin (project dashboard), narrated and edited entirely by DemoDay, including the sea-captain voiceover using ElevenLabs.

📱 Shorts

The same project can also be cut into a vertical Short for YouTube Shorts, Instagram Reels and TikTok — say "make a short" (or "vertical video", "Reel", "TikTok") and Claude picks one of four named styles with you:

Sample listicle Short for Social Cue, a Claude plugin that finds conversations worth joining. The presenter is an AI avatar made from a photo of the author, speaking with a designed ElevenLabs voice; the "it browses for you" beat is a Remotion animation instead of screen capture, timed to the narration word by word.

✨ What you get

• 🖱️ Claude drives your app — it rehearses off camera first, then a deterministic runner performs the take with smooth cursor moves and human typing. No dead air, no fumbling.
• 🎙️ AI voiceover with word-timed captions — narration is generated first, so every scene lands exactly on the voice.
• 🧑‍💼 Optional on-camera presenter — an AI presenter for the intro, outro and cutaways, lip-synced to the same voice as the narration.
• 🧭 Wide videos in named styles too — launch (classic promo), anchor (avatar-led), explainer (no face), or tutorial: a step-by-step walkthrough with the full workflow on screen and the presenter riding along as a corner bubble (circle or rounded square, any corner).
• 🗣️ Custom character voices — describe a voice in plain English ("weathered lobster-boat captain, thick coastal accent") and the whole demo is narrated in it.
• 🎞️ Real editing, not a screencast — title cards, transitions, zoom-to-click, callouts, b-roll and audio ducking, rendered with Remotion.
• 📱 Vertical Shorts too — cut a 15–45s 9:16 Short (YouTube Shorts, Reels, TikTok) from the same project in one of four named styles: listicle, cohost, flashcard or glide.
• 💻 Films almost anything on a Mac — web apps, native macOS apps, and CLI/terminal programs (yes, it can demo a Claude Code plugin from inside a live claude session).
• 🔁 Cheap to iterate — change one line of narration and only that line is regenerated. A cost estimate is shown before anything is spent.

🚀 Install

In Claude Code:

/plugin marketplace add mrieck/claude-plugins
/plugin install demoday@productive-mark

(productive-mark is the marketplace, hosted in mrieck/claude-plugins; demoday is the plugin — this repo.)

That's it for software — no npm install, no manual dependency setup. The first time you run /demoday:create-demo-video, Claude checks your machine and installs anything missing (Node packages, a capture browser, ffmpeg) before filming starts.

Requirements: macOS and Claude Code. The only thing Claude can't do for you is the two steps below.

1. Add your fal.ai key (required)

All generation — voice, presenter, b-roll — runs through fal.ai. Store the key in your macOS Keychain by running this in your own terminal (not through Claude, so the key never touches a transcript):

security add-generic-password -s demoday -a FAL_API_KEY -w

It prompts for the key without echoing it. A typical 30-second demo costs $1–2 in fal credits.

Not on Keychain terms? Every other place a key can live is covered in HOW_IT_WORKS.md.

2. Grant screen permissions (desktop capture only)

To film a native Mac app, give the terminal you run Claude Code from (Terminal, iTerm, VS Code…) Screen Recording and Accessibility in System Settings → Privacy & Security, then restart the terminal. Filming web apps and CLI demos in a staged terminal window needs no permissions at all — and if anything's missing, Claude tells you the exact Settings pane during preflight.

Optional keys

Same Keychain one-liner, different account name:

• ELEVENLABS_API_KEY — unlocks custom character voices via ElevenLabs Voice Design (affiliate link). Needs a paid ElevenLabs plan (Starter and up): the free tier blocks voice creation over the API, and a paid plan also carries the commercial license you'd want for a published video anyway.
• BRAVE_API_KEY — lets b-roll generation search reference images.

🔒 What leaves your machine

Screen recordings, rehearsal screenshots and the finished MP4 stay local. Only what generation needs is uploaded: narration text, narration audio, the presenter image and b-roll frames go to fal.ai — and narration text to ElevenLabs if you use it. API keys are only ever read, never written (details).

🎥 Make your first video

From the repo of the software you want to show off:

/demoday:create-demo-video

Claude will read the codebase, pitch you two or three flows worth filming, ask about goal, audience, length and presenter style, and show you the cost estimate. Only after you say yes does it generate a single frame. Ten-ish minutes later there's an MP4 in that video's project folder under demo/ (each video gets its own, e.g. demo/project-overview/).

🔍 Under the hood

The interesting bits — the two-pass rehearse/perform design, narration-first pacing, the demo.json manifest, content-addressed caching, and everything about API-key resolution — live in HOW_IT_WORKS.md.

📄 License notes

Rendering uses Remotion, which is free for individuals and small companies but needs a paid license above a headcount threshold — see remotion.dev/license. Voices generated on a paid ElevenLabs plan include commercial usage rights.

To subscribe to an ElevenLabs plan that allows commercial use, click here (affiliate link).

DemoDay itself is MIT licensed.