melonjs-20-migration SKILL.md skillA
melonjs-20-migration from melonjs/melonjs is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add melonjs/melonjs/melonjs-20-migration@git:20260831.8e2f9bePins git:20260831.8e2f9be in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- melonjs/melonjs
- Path
packages/melonjs/skills/melonjs-20-migration/SKILL.md- Versions recorded
- 1
- Latest version
- git:20260831.8e2f9be, committed Aug 31, 2026
- Size
- 7,594 bytes
- Repository stars
- 6,441
- License
- MIT
Use this skill when writing melonJS code that may be based on pre-20.x knowledge, when migrating a game from melonJS 19.x or earlier, or when an API you expected does not exist. Covers the mandatory async Application.init(), the WebGL 2 baseline and WebGPU backend, renderable post effects replacing the shader property, and the deprecated exports still present. Triggers on: migration, upgrade, melonJS 19, me.game, me.video.init, renderable.shader, Compositor, CanvasTexture, me.Math, deprecated.
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# Migrating to melonJS 20.x
> What changed in melonJS 20.x, and which older APIs are gone, deprecated, or
> renamed. Read this before writing melonJS code from memory — much of what is
> published about melonJS predates 20.0.
**Why this skill exists:** most melonJS material in circulation describes 19.x or
earlier. Code written from that knowledge looks correct and fails at runtime.
The items below are ordered by how likely they are to be reproduced from memory.
## 1. `Application.init()` is mandatory and asynchronous
Since 20.0, constructing an `Application` no longer initialises it.
```js
// ✗ pre-20.x — the constructor called init(width, height, options) for you
const app = new Application(800, 600, { parent: "screen" });
app.world.addChild(sprite); // added, but nothing ever renders
// ✓ 20.x
const app = new Application(800, 600, { parent: "screen" });
await app.init(); // REQUIRED
app.world.addChild(sprite);
```
`init()` is async because acquiring a WebGPU device is async. There is no
synchronous alternative, and no automatic fallback that papers over the missing
call. Nothing that then breaks names it: the constructor still builds
…Read the whole file at its exact version.
How to install
mdr add melonjs/melonjs/melonjs-20-migration@sha256:963531aa705190a7The line at the top of this page pins the label git:20260831.8e2f9be, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_l3siyysmgvtup7wc)
1 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 1 version of this file, committed on Aug 31, 2026.
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (7594 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
melonjs/melonjs · 6,441 stars · license MIT · pushed 2026-11-06 · branch master
API
GET https://markdownregistry.com/api/v1/artifacts/art_l3siyysmgvtup7wc GET https://markdownregistry.com/api/v1/resolve?ref=melonjs/melonjs/melonjs-20-migration GET https://markdownregistry.com/api/v1/blob/963531aa705190a762dd439f1710c2f52892bb6a6e41f695bcc2cba12b305c04
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.