Docs / Ship

Runtimes

The .egg file

Export bakes a project into a compact binary: artboards, animations, state machines, view models, and the pictures, sounds and fonts it needs (or, with --referenced, a folder of assets your app hands over at run time). A bundle (.eggs) holds several artboards.

Web

The web runtime is WebAssembly plus a small helper, egg-player.js, that sizes the canvas, runs the frame loop and forwards pointer, wheel, keyboard and text input.

index.htmlweb runtime

import init, * as egg from "./egg_web.js";
import { mount } from "./egg-player.js";

await init();
const bytes = new Uint8Array(await (await fetch("hatch.egg")).arrayBuffer());
const view = mount(egg, document.querySelector("canvas"), bytes, {
  machine: "hatch",     // "" = the first; null = play the first animation
  fit: "contain",       // or "layout": the artboard takes the canvas size
});

Option	Does
`artboard`	Which artboard of a bundle ("" = the first).
`renderer`	"canvas" (default, Canvas2D) or "pixels" (software, exact).
`openUrls`	Follow "open URL" events (default true).
`sound`	Play audio events (default true).
`onEvent`	A function called with every event the file reports.
`semantics`	Mirror tappable shapes as accessible elements (default true).

Native and engines

One runtime written in Rust, with a C API and bindings on top of it:

Platform	Binding
iOS, macOS	Swift package
Android	Kotlin (AAR)
Flutter	Dart packages (runtime and a player widget)
Unity	C# package
Unreal	Plugin
C, C++ and anything with an FFI	egg.h and egg.hpp

Driving it from code

Every runtime exposes the same calls: start a state machine, set its inputs (set_bool, set_number, fire), read and write view model properties (vm_set_number, vm_fire, …), read the current state and take the events the file reported.