AirSlide

Change slides by swinging an AirPod.

AirSlide turns one AirPod into a presentation remote. Hold it between two fingers, turn your wrist right for the next slide and left to go back. A native macOS app reads the AirPod's motion sensor and recognises deliberate swings. A small relay then moves every open copy of your deck at once: your laptop, the projector and anyone following along remotely.

• Native and private. Motion is processed on the Mac. Only the gesture leaves it: next or prev, and which AirPod.
• Calibrated to you. A six-step setup learns your own right and left wrist turn, then lets you practise without moving any slides.
• Every screen follows. One gesture reaches every browser that has the deck open, with a short 3D AirPod animation.
• Any HTML deck. Anything that moves on the arrow keys works without changes, including reveal.js and most hand-built decks.

AirPod ──Core Motion──▶ AirSlide.app ──HTTPS + key──▶ relay ──WebSocket──▶ every open deck

1. The Mac app reads the AirPod's rotation rate through CMHeadphoneMotionManager. Calibration records the axis, direction and strength of your right and left swing, and stores a separate threshold for each.
2. A swing detector arms only after a moment of stillness and waits out a cooldown after each gesture, so returning your wrist to neutral never goes back a slide.
3. On a swing, the app posts a command such as {"direction": "next", "id": "<uuid>", "side": "right"} to the relay's /api/command, with your key as a bearer token.
4. The relay serves your deck, adds a small client script to every page, and broadcasts the command over a WebSocket. The client presses the arrow key the deck already understands and plays the AirPod animation.

• An Apple Silicon Mac with macOS 14 Sonoma or later and the Xcode command line tools (xcode-select --install).
• AirPods with head tracking: AirPods Pro, AirPods (3rd generation or later) or AirPods Max.
• Node.js 22 or later for the relay.

Create one key for the app and the relay, then run the relay with the bundled example deck:

git clone https://github.com/Tarabcak/airslide.git
cd airslide
npm install

mkdir -p ~/.config/airslide && chmod 700 ~/.config/airslide
printf 'REMOTE_TOKEN=%s\n' "$(openssl rand -hex 32)" > ~/.config/airslide/local-relay.env
chmod 600 ~/.config/airslide/local-relay.env

REMOTE_TOKEN="$(sed -n 's/^REMOTE_TOKEN=//p' ~/.config/airslide/local-relay.env)" npm start

The relay now serves the example deck at http://127.0.0.1:8094. In a second terminal, in the same folder, build and open the app:

bash scripts/build-mac.sh
open build/AirSlide.app

Follow the setup. It asks for Motion & Fitness access when your AirPods connect, then walks you through the grip and both calibration swings. Turn off Automatic Ear Detection for your AirPods (System Settings, then your AirPods) so an AirPod keeps reporting motion outside your ear.

When setup is done, open Settings → Device & view and switch on Local rehearsal on this Mac. Back on the Control screen, choose Open deck, turn on Presentation control and swing right.

Run the relay where every viewer can reach it over HTTPS. The app only sends the key over HTTPS, or over plain HTTP to this Mac.

With Docker, serving your own deck (create the key with openssl rand -hex 32):

export REMOTE_TOKEN="<your key>"
docker build -t airslide-relay .
docker run -d --name airslide --restart unless-stopped \
  -p 127.0.0.1:8080:8080 \
  -e REMOTE_TOKEN="$REMOTE_TOKEN" \
  -e DECK_DIR=/deck -v "$PWD/my-deck:/deck:ro" \
  airslide-relay

Then put a TLS proxy in front of it. With Caddy, which also forwards WebSockets:

slides.example.com {
	reverse_proxy 127.0.0.1:8080
}

On the presenting Mac, copy relay.env.example to ~/.config/airslide/relay.env, fill in your relay's URL and key, chmod 600 it, and turn local rehearsal off. Everyone opens https://slides.example.com/.

Commands are relative, so every screen should start on the same slide. A screen that joins late moves from wherever it is.

Point the relay at the folder that holds your deck's index.html:

REMOTE_TOKEN="$(sed -n 's/^REMOTE_TOKEN=//p' ~/.config/airslide/local-relay.env)" \
  DECK_DIR=/path/to/my-deck npm start

The relay injects its client into every HTML page in that folder. Decks that move on → and ← work as they are. If yours navigates some other way, define a hook and AirSlide calls it instead of pressing a key:

window.airslideNavigate = direction => direction === 'next' ? deck.next() : deck.prev();

The relay serves common web files (HTML, CSS, JavaScript, JSON, images, fonts, audio, video and PDF). Hidden files, other file types and anything outside the folder return 404. To tune the AirPod animation against your deck without sending commands, open /_airslide/preview.html on the relay.

Gesture sensitivity, the time between gestures, reversed directions and the hand guide are set in the app and saved automatically.

• The key is the only thing that can move your slides. Keep it in the config file and the relay's environment. If it leaks, restart the relay with a new key and update the Mac.
• Watching needs no key. Anyone with the deck's URL can view it, so keep confidential decks off public hosts.
• The relay accepts at most four commands a second, ignores repeated command IDs for a minute and limits requests and WebSocket messages to 1 KB and connected viewers to 500.
• Motion samples never leave the Mac. The relay only sees the direction and which AirPod was used.

• No motion. Check System Settings → Privacy & Security → Motion & Fitness, wear both AirPods for a moment, then choose Retry motion. AirSlide retries on its own three times first.
• Motion stops when you take the AirPod out. Turn off Automatic Ear Detection for your AirPods.
• "Sensor switched. Recalibrate for this AirPod." macOS reports motion from one AirPod at a time. If it switches sides, run calibration again with the AirPod you are holding.
• Swings are missed or fire twice. Turn your wrist rather than moving your arm, since AirSlide measures rotation. Adjust sensitivity and the time between gestures in Settings, or recalibrate.
• "Relay not configured." The app could not find a valid REMOTE_URL and a key of 32 or more characters in the config file shown in Settings.
• Opening a copied build on another Mac. Builds are ad-hoc signed, not notarised, so macOS blocks a copy from elsewhere. Build on that Mac, or try to open the app once and then allow it in System Settings → Privacy & Security → Open Anyway.

npm test                    # relay: auth, validation, broadcast, file boundary
bash scripts/test-mac.sh    # app: swing detector, calibration, setup flow, relay config
bash scripts/build-mac.sh   # builds build/AirSlide.app

MIT, see LICENSE. The bundled three.js, AirPods Pro model and hand mesh keep their own licences, listed in THIRD_PARTY_NOTICES.md.

AirPods is a trademark of Apple Inc. AirSlide is an independent project, not affiliated with or endorsed by Apple.