What is PairKit

PairKit is a Unity SDK plus a hosted relay that turns any phone into a game controller for any Unity scene. The player visits a URL on their phone (typically by scanning a QR code shown on screen), and a controller UI — buttons, joystick, d-pad, drawing canvas, whatever the host configured — appears in their phone’s browser. Their input flows back to Unity in real time over a WebSocket.

There is no app to install on the phone. There is no SDK code on the phone side — just a browser and a URL. Unity is the only side you ship code to.

What PairKit gives you

• A drop-in Unity package with a single MonoBehaviour (PhoneControllerManager) as the public surface.
• Twelve widget types you can compose into controllers.
• Multi-screen Flows for richer gameplay (lobbies, voting rounds, drawer-and-guesser).
• A hosted relay at relay.pairkit.dev, plus a LAN-mode transport for in-person events with no internet.
• An engine-agnostic wire protocol — Unreal, Godot, and other engines can implement the same protocol later.

What PairKit is not

• It is not a multiplayer netcode library. Unity is the authoritative game state; PairKit only delivers controller input from phones to your scene.
• It is not a phone-to-phone messaging system. All traffic flows through the host’s Unity scene.
• It is not a low-latency competitive-shooter input layer. Network round-trip is fine for party games, prototypes, kiosks, and casual play; it is not tuned for sub-frame latency.

If those constraints fit, PairKit removes the hardest part of phone-as-controller: shipping mobile builds, App Store review, OS-version churn. Everyone has a browser.