A TypeScript-first browser 2D engine for games and interactive apps.

Try the playground · Read the guide · Browse the API

ExoJS combines an explicit scene graph with WebGPU/WebGL2 rendering, physics, audio, UI, assets, serialization, and focused extension packages. It is built as one coherent runtime rather than a renderer surrounded by unrelated integrations.

Pre-1.0: the public API is still being refined, and minor releases may contain breaking changes. Pin exact versions in downstream projects. 1.0.0 will mark the first stable API contract.

Why ExoJS

TypeScript is the design input	Strict types, discoverable APIs, typed assets and extension contracts, with noUncheckedIndexedAccess and exactOptionalPropertyTypes throughout.
Two real graphics backends	WebGPU-first rendering with automatic WebGL2 fallback, backend parity tests, custom GLSL/WGSL materials, render targets, filters, and readback.
A complete 2D runtime	Scenes, cameras, input, UI, text, audio, persistence, serialization, coroutines, and deterministic lifetime management ship together.
Serious optional systems	Native rigid-body physics, GPU particles, tilemaps, lighting, pathfinding, React bindings, and format adapters stay opt-in and tree-shakeable.
Explicit ownership	Application-scoped managers, local extension descriptors, and Destroyable/DisposalScope lifetimes avoid hidden global state.
Performance is reproducible	Structural CI gates and browser/GPU benchmark profiles record the workload, hardware, browser, versions, medians, p95s, and measurement spread.

Start in 30 seconds

Create a project and choose a starter interactively:

npm create exo-app@latest my-game
cd my-game
npm install
npm run dev

Or select a template directly:

npm create exo-app@latest my-game -- --template minimal
npm create exo-app@latest my-game -- --template platformer
npm create exo-app@latest my-game -- --template top-down

The smallest application is still ordinary TypeScript:

import { Application, Color, Graphics, type RenderingContext, Scene, type Seconds } from '@codexo/exojs';

class MainScene extends Scene {
  private readonly box = new Graphics();

  public constructor() {
    super();

    this.box.fillColor = Color.white;
    this.box.drawRectangle(-40, -40, 80, 80);
    this.box.setPosition(400, 300);
    this.addChild(this.box);
  }

  public override update(delta: Seconds): void {
    this.box.rotate(delta * 90);
  }

  public override draw(context: RenderingContext): void {
    context.render(this.root);
  }
}

const app = new Application({
  scenes: { MainScene },
  canvas: { width: 800, height: 600, mount: 'body' },
  clearColor: new Color(0x6495ed),
});

await app.start(MainScene);

Continue with the guide, inspect runnable code in the playground, or look up a symbol in the API reference.

What you can build

Rendering and presentation

• Sprites, animated sprites, nine-slice and repeating sprites, immediate geometry, instanced batches, SDF text, bitmap text, and video.
• WebGPU and WebGL2 backends selected automatically or explicitly through ApplicationOptions.backend.
• Render textures, retained render plans, filter chains, visual masks, cache-as-bitmap, custom sprite materials, and custom renderers through the public renderer SDK.
• Linear and radial gradients, pixel snapping, blend modes, frame passes, asynchronous pixel readback, and render statistics including GPU memory and upload accounting.
• Forward, shadowed lightmap, and radiance-cascade lighting through @codexo/exojs-lighting, with normal maps, multiple light shapes, cookies, and reusable occluder sources.

Worlds and gameplay

• Scene navigation with preload/unload, pause/resume, and built-in or custom transitions.
• Cameras with follow, shake, zoom, bounds clamping, and multiple views.
• Keyboard, pointer, touch, and gamepad input with action bindings, focus traversal, hit areas, and modal focus scopes.
• Native 2D rigid-body physics with continuous collision, joints, sensors, sleeping islands, contact modification, queries, and a debug overlay.
• Weighted-grid and waypoint-graph pathfinding, streamed tilemap worlds, Tiled and LDtk adapters, and Aseprite animation import.

Player experience and application state

• Screen-fixed UI widgets, themes, anchoring, scrolling, tooltips, progress bars, and labels.
• Spatial audio, audio sprites, generated and streamed sources, buses, effects, analysis, worklets, and beat detection.
• Typed asset catalogs, deduplicated loading, scoped asset lifetimes, binary containers, and persistent key-value stores.
• Scene serialization, prefabs, deterministic systems, tweens, signals, and frame-budgeted coroutines for long-running work.

Packages

Install only the systems your project uses. Official runtime packages share the Core release line and declare compatible peer ranges.

Package	Purpose
@codexo/exojs	Core scene, rendering, audio, UI, asset, and serialization runtime
@codexo/exojs-physics	Native 2D rigid-body physics with a TGS-Soft solver
@codexo/exojs-particles	GPU-compute particle simulation with a CPU fallback
@codexo/exojs-tilemap	Format-neutral tilemap runtime, streaming, object spawning, and rendering
@codexo/exojs-tiled	Tiled JSON adapter
@codexo/exojs-ldtk	LDtk world and level adapter
@codexo/exojs-aseprite	Aseprite sprite-sheet and animation adapter
@codexo/exojs-tilemap-physics	Static physics colliders generated from tilemap collision geometry
@codexo/exojs-lighting	Forward, shadowed lightmap, and radiance-cascade 2D lighting
@codexo/exojs-pathfinding	A* pathfinding over weighted grids and waypoint graphs
@codexo/exojs-audio-fx	Audio effects, worklets, analysis, and beat detection
@codexo/exojs-react	React canvas hosting, scene composition, and hooks

Project tooling is available separately:

Package	Purpose
create-exo-app	Interactive project scaffolding and maintained starters
@codexo/exojs-cli	Static serving, project checks, scaffolding, and asset packs
@codexo/exojs-build	Vite/Rollup transforms for shaders, workers, and AudioWorklets
@codexo/eslint-plugin-exojs	Lifecycle and hot-path correctness rules for ExoJS projects

Installation and distribution

npm install @codexo/exojs

ExoJS is ESM-first and works with modern bundlers. Optional packages install independently, for example:

npm install @codexo/exojs @codexo/exojs-physics @codexo/exojs-lighting

Prebuilt script-tag bundles are also included: dist/exo.iife.js contains Core, while dist/exo.full.iife.js contains Core and the official runtime extensions except React. Both expose the Exo global. Minified variants are provided alongside them.

Measured performance

ExoJS maintains two complementary kinds of performance evidence:

• deterministic structural gates for draw calls, batches, binds, uploads, and other exact work counters;
• real-browser comparison profiles for rendering and physics, with pinned competitors and stamped hardware, browser, workload, warmup, sample count, median, p95, and run-to-run spread.

The numbers are deliberately not copied into this README because they change with the engine, competitor versions, browser, and reference machine. Read the current published profiles and the benchmark methodology together.

Roadmap

Work toward the 1.0.0 API freeze is directional, not a release commitment. Current longer-term areas include:

• rich text with style spans and inline content;
• worker-backed execution through the same coroutine ownership model;
• platform adapters for Worker and headless runtimes;
• the final public API audit and stabilization pass.

Contributing

Development requires Node 24 and the pnpm version pinned in package.json.

pnpm bootstrap:dev
pnpm doctor

bootstrap:dev installs dependencies and hooks, builds Core and every package, links benchmark competitors, installs Chromium, and reports anything still missing. During development, use the narrow command for the area you changed:

pnpm typecheck
pnpm lint
pnpm test
pnpm build:all
pnpm lanes

See CONTRIBUTING.md for branch policy, imports, package boundaries, public API conventions, validation, and distribution rules.

Links

• GitHub Pages: https://exoridus.github.io/ExoJS/
• Guide: https://exoridus.github.io/ExoJS/en/guide/
• API reference: https://exoridus.github.io/ExoJS/en/api/
• Playground: https://exoridus.github.io/ExoJS/en/playground/
• Repository: https://github.com/Exoridus/ExoJS
• Releases: https://github.com/Exoridus/ExoJS/releases
• Issues: https://github.com/Exoridus/ExoJS/issues
• Changelog: CHANGELOG.md

License

MIT © Codexo