# ecsyjs/ecsy

Entity Component System for javascript

Repository: https://github.com/ecsyjs/ecsy
Canonical: https://ross.abutalabs.com/products/ecsy
Homepage: https://ecsyjs.github.io/ecsy/
Language: JavaScript
License: MIT
License Family: permissive
Archived: true
Last push: 2025-04-13T09:44:36+00:00

## Health v2 (maintenance only)
Score: 10/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 16, release rhythm 8, longevity 100
- inputs: {"age_days": 2672, "days_push": 507, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: archived
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1156, forks 121 (observed 2026-08-28T04:03:48.090232+00:00)

## What it is
ECSY is a lightweight, framework-agnostic Entity Component System (ECS) framework for JavaScript, originally developed by the Mozilla Mixed Reality team. It organizes game and application logic into entities, data-only components, and ordered systems with reactive queries, designed to integrate with rendering engines like three.js or Babylon.js via community adapters.

## Use cases
- build a game with an entity component system architecture in javascript
- manage game logic decoupled from rendering engines like three.js or babylon
- write reactive systems that respond to entity and component changes
- avoid garbage collection pauses in a javascript game loop
- structure a 2D canvas game with composable systems and components
- prototype web-based mixed reality or 3D applications with an ECS pattern

## When to choose
- you want a lightweight, framework-agnostic ECS in JavaScript or TypeScript
- you need predictable system execution order and queued reactive events
- you're building on three.js, Babylon.js, or canvas and want community ECS adapters
- you prefer simple APIs over strict pure-ECS dogma

## When to avoid
- you need a full-featured, production-hardened game engine with rendering built in
- you require strict pure ECS design with no ergonomic compromises
- you need a mature, actively maintained library - it is explicitly labeled highly experimental
- you're working outside JavaScript/web platforms

## Facets
- artifact type: library
- maturity: experimental
- function: game-engine, animation
- domain: web-development, graphics
- platform: browser
- tags: ecs, entity-component-system, game-architecture, framework-agnostic, reactive-systems, performance, game-development, javascript, nodejs, web

## Member repositories
- ecsyjs/ecsy (main) score 10

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:03:48.090232+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T06:32:07.222040+00:00, confidence not recorded.
  - readme: https://github.com/ecsyjs/ecsy (fetched 2026-08-28T04:03:48.090232+00:00, sha ec62e4f74252)
  - homepage: https://ecsyjs.github.io/ecsy/ (fetched 2026-08-29T12:37:28.620109+00:00, sha 192934991d7c)
- Data as of 2026-08-30T08:39:29.467469+00:00.