KIN — Living Worlds, Crossing Screens
A tiny, original, autonomous creature that lives under your real sky, and can hop off your
screen onto a friend's. Web, iPhone and iPad from one codebase.
Place two windows side by side. Your KIN notices the other one, pads toward the seam, glances
back at you, hops across, and lands on the other screen, where that KIN reacts in its own way.
Call it home and it comes back with a memory.
Live: https://mutaafaziz.com/kin/ · Guide: https://mutaafaziz.com/kin/guide/ · iPhone/iPad via TestFlight (npm run testflight, see docs/TESTFLIGHT.md)
Link two devices (no codes, nothing to scan)
Open KIN on both, put them side by side, and slide one finger off one screen onto the other.
They link, the edge glows, and Gather → Visit sends your KIN across.
Run it
npm run up # install if needed, typecheck, run tests, start http://localhost:5188/kin/
npm run ios:sim # build the native app and launch it on an iPhone and an iPad simulator
npm run ios # open in Xcode (to run on a physical device)
npm run check # typecheck + tests + production web build
Demo the crossing (same device)
- Open http://localhost:5188/kin/ and tap the cocoon twice to hatch it.
- Open Gather → Open a friend window, and hatch the second KIN too.
- Put the windows side by side and press Visit. The KIN walks to the facing edge, peeks back
at you, and hops across. Whether the other window must accept depends on its "Who can visit" setting.
- Call home brings it back. The Memory Book records what happened.
Demo URL switches
?wx=rain|storm|snow|wind|heat|cold|clear overrides the weather. ?hour=6.5 sets the time of
day. ?debug shows the brain's reasoning and fps. ?k=<slot> picks which home (each window is
its own home).
Privacy and ads
The app collects nothing and needs no account. Per the owner's 2026-10-30 decision to monetize the
collection, the landing page (/kin/about/, web only) carries one child-directed banner served
by Marquee: kid-safe sponsors only, no click-outs, never in the app or over the creature, and none
in the iPhone/iPad build. Ad policy: https://mutaafaziz.com/ads/privacy/
What's real today
See docs/PLAN.md for sprint status and the honest list of limitations. The phone-to-phone relay
is next. Engineering principles: docs/ENGINEERING.md. Original vision: docs/blueprint/.
Layout
src/core creature, genome, utility-AI brain (pure, no DOM)
src/protocol versioned envelope + validation
src/session KIN CROSS state machines (pure) + session shell (presence, clock sync)
src/transport BroadcastChannel + WebSocket relay (merged, de-duplicated)
src/stitch invisible pairing: gesture detector + matcher (shared with the Worker)
src/worker Cloudflare Worker + Lobby Durable Object (relay)
src/env live sky: sun position, weather, coarse/precise location
src/render three.js stage, procedural creature, animation, crossing choreography
src/ui HUD; src/audio synthesized sfx; src/platform native haptics/status bar
ios/ Capacitor iOS/iPadOS shell
