Phaser Build

Phaser 4 Build and Deployment

Development Server

Start the dev server with hot reload:

npm run dev

Opens at http://localhost:5173 (Vite default). Changes auto-reload in the browser.

Production Build

npm run build     # Compiles TypeScript + bundles with Vite → dist/
npm run preview   # Serve the dist/ folder locally to test production build

Output in dist/ — static files ready for any web host.

Diagnose the Project

Run the validation script before building:

bash scripts/validate-project.sh

The script checks for common issues automatically.

TypeScript Type Checking

npx tsc --noEmit

Fix all type errors before shipping. Common Phaser 4 TypeScript issues:

Missing Phaser types:

// tsconfig.json — Phaser 4 resolves its own types via its exports map
{
  "compilerOptions": {
    "module": "ESNext",
    "moduleResolution": "bundler",
    "skipLibCheck": true
  }
}

Then import it explicitly in each file: import Phaser from 'phaser';

If you see TS2688: Cannot find type definition file for 'Phaser', the project is carrying the v3-era typeRoots + types: ["Phaser"] pair. Delete both keys — Phaser 4 ships a single types/phaser.d.ts, which is not a valid type-root package.

this.input.keyboard nullable:

// Wrong:
const cursors = this.input.keyboard.createCursorKeys();
// Correct:
const cursors = this.input.keyboard!.createCursorKeys();

sprite.body nullable:

// Wrong:
sprite.body.velocity.x
// Correct:
(sprite.body as Phaser.Physics.Arcade.Body).velocity.x
// Or:
sprite.body?.velocity.x

this.scene.get() returns base Scene type:

// Cast to specific scene class:
const game = this.scene.get('GameScene') as GameScene;

Common Build Errors

"Cannot find module 'phaser'"

npm install phaser   # installs Phaser 4 (latest stable). Do NOT use phaser — that tag still points at 4.2.1

Asset 404 Errors (game loads but assets missing)

In Vite, assets must be in the public/ directory. They are served as-is at the root.

✅ public/assets/images/sky.png  → loads as 'assets/images/sky.png'
❌ src/assets/images/sky.png     → won't work with this.load.image()

Never import assets via ES imports for Phaser. Just reference the path string:

this.load.image('sky', 'assets/images/sky.png');  // ✅

"Phaser.Geom.Point is not a constructor"

v3 → v4 breaking change. Replace with Vector2:

// Old (v3):
const pt = new Phaser.Geom.Point(x, y);
// New (v4):
const pt = new Phaser.Math.Vector2(x, y);

"Math.PI2 is undefined"

v3 → v4 breaking change:

// Old (v3):
const angle = Math.PI2;        // was π (wrong!) in v3
// New (v4):
const angle = Math.TAU;        // π×2
const half = Math.PI_OVER_2;   // π/2

Black Screen on Launch

1. Check browser console for errors (F12)
2. Check for 404s in Network tab (missing assets)
3. Verify scene is in GameConfig's scene: [] array
4. Verify HTML has <div id="game-container"> if using parent: 'game-container'
5. Try removing parent config to append to document.body directly

WebGL Context Lost

// Try Canvas renderer as fallback
const config = {
  type: Phaser.CANVAS,   // instead of Phaser.AUTO or Phaser.WEBGL
  // ...
};

Or add WebGL context loss recovery listener:

this.game.renderer.on('contextlost', () => {
  console.warn('WebGL context lost — attempting recovery');
});

Vite Configuration

// vite.config.ts
import { defineConfig } from 'vite';

export default defineConfig({
  base: './',             // IMPORTANT for itch.io and subdirectory deployment
  build: {
    outDir: 'dist',
    assetsDir: 'assets',
    minify: 'terser',
    rollupOptions: {
      output: {
        manualChunks: {
          phaser: ['phaser'],  // Bundle Phaser separately for caching
        },
      },
    },
  },
  server: {
    port: 5173,
  },
});

base: './' is critical for itch.io, GitHub Pages, and any subdirectory deployment. Without it, assets load from / (root) which breaks on subdirectory hosts.

Deployment Targets

This section covers the mechanics of getting a build onto a host. For deciding whether the game is ready — the readiness gate, versioning, store presence, launch day — see skills/phaser-release/.

itch.io

1. npm run build
2. Zip the dist/ folder contents (not the folder itself — zip what's inside)
3. Upload the zip to itch.io → "Upload files" → HTML game
4. Set "This file will be played in the browser"
5. Check "SharedArrayBuffer support" if needed

GitHub Pages

# .github/workflows/deploy.yml
name: Deploy to GitHub Pages
on:
  push:
    branches: [main]
jobs:
  deploy:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - uses: actions/setup-node@v3
        with: { node-version: '18' }
      - run: npm ci
      - run: npm run build
      - uses: peaceiris/actions-gh-pages@v3
        with:
          github_token: ${{ secrets.GITHUB_TOKEN }}
          publish_dir: ./dist

Set base: '/repo-name/' in vite.config.ts for GitHub Pages (subdirectory).

Netlify / Vercel

Connect the git repo. Set:

• Build command: npm run build
• Output directory: dist

Both auto-deploy on push to main.

Capacitor (iOS/Android)

npm install @capacitor/core @capacitor/cli @capacitor/ios @capacitor/android
npx cap init
npx cap add ios
npx cap add android
npm run build
npx cap sync
npx cap open ios    # Opens Xcode
npx cap open android  # Opens Android Studio

Performance Checklist Before Shipping

• arcade: { debug: false } in GameConfig
• Assets in texture atlases (not individual images)
• Audio compressed (128kbps MP3 for BGM, 96kbps for SFX)
• Object pooling for bullets/particles/enemies
• maxParticles set on all particle emitters
• npx tsc --noEmit passes with 0 errors
• Tested in Chrome, Firefox, and Safari
• Mobile tested (if targeting mobile)

For a detailed performance playbook (measurement-first prompting, per-frame allocation elimination, spatial grid, audio lazy-load, atlas packing, tween leak fixes), see skills/phaser-analyze/references/performance-playbook.md. Use /phaser-analyze for a full project audit before shipping if FPS is a concern.

Scripts

Run the project validator:

bash scripts/validate-project.sh

The validator checks: Phaser version, tsconfig fields, presence of scene files, deprecated v3 API usage.