Field notes · Live demo · Studio

Sign a four-digit PIN at a camera.

The signless / touchless thesis made into a thing you can poke at right now. 36 handshapes, in your browser, on the camera you already have. No install. No app. No microphone.

Live in your browser ~30 sec setup Camera required By 1891 · Frederick, MD

Run the demonstration.

Grant camera access, hold up the handshape for each digit, and watch your PIN appear. Works on phone or laptop.

Launch the demo  → Runs in your browser. Nothing to install.

What it proves.

How we built it.

The demo runs entirely in the browser. An on-device recognizer trained on a small handshape dataset reads the camera feed in real time and emits one of 36 classes per frame. A short stability window suppresses jitter — you have to hold the shape for ~250ms before it commits to the PIN. The whole thing is one HTML file with no server roundtrip.

Why this matters. The classifier is small enough to run on five-year-old phones. The interaction is fast enough to feel like a keypad. The accuracy is high enough for a four-digit PIN. None of those numbers required a frontier-model API or a custom GPU. We built it as the proof point that the touchless-world thesis is shippable today, not pending some research breakthrough.

The essay it goes with.

The longer thinking behind this demo lives in the essay The case for a touchless, signless world — a five-page case for why interactive systems shouldn't assume you can speak, and what the cure looks like in practice.