Packaging

Once your launcher is ready, the final step is to produce platform-specific installer files that your players can download. EML uses electron-builder for this task.

Prerequisites

Prepare the following icon assets in a build/ folder at the root of your project:

Configuration

Create electron-builder.yml at the root of your project. Using a dedicated file keeps package.json clean.

appId: com.myserver.launcher
productName: 'My Server Launcher'
copyright: 'Copyright © 2026 My Server'

directories:
  output: release
  buildResources: build

files:
  - "dist",
  - "dist-electron",
  - "package.json",
  - "!**/node_modules/*/{CHANGELOG.md,README.md,README,readme.md,readme}",
  - "!**/node_modules/*/{test,__tests__,tests,powered-test,example,examples}",
  - "!**/node_modules/*.d.ts",
  - "!**/node_modules/.bin",
  - "!**/*.{iml,o,hprof,orig,pyc,pyo,rbc,swp,csproj,sln,xproj}",
  - "!.editorconfig",
  - "!**/._*",
  - "!**/{.DS_Store,.git,.hg,.svn,CVS,RCS,SCCS,.gitignore,.gitattributes}",
  - "!**/{__pycache__,thumbs.db,.flowconfig,.idea,.vs,.nyc_output}",
  - "!**/{appveyor.yml,.travis.yml,circle.yml}",
  - "!**/{npm-debug.log,yarn.lock,.yarn-integrity,.yarn-metadata.json}"

publish:
  provider: generic
  url: 'https://myserver.com/'

win:
  target: nsis
  icon: build/icon.ico

nsis:
  oneClick: false
  perMachine: false
  allowToChangeInstallationDirectory: true
  shortcutName: 'My Server'
  createDesktopShortcut: true
  createStartMenuShortcut: true
  deleteAppDataOnUninstall: true
  artifactName: '${productName} Setup ${version}.${ext}'

mac:
  target:
    - dmg
    - zip
  icon: build/icon.icns
  category: public.app-category.games
  hardenedRuntime: true
  gatekeeperAssess: false
  artifactName: '${productName} ${version}.${ext}'

dmg:
  title: 'Install My Server'
  contents:
    - x: 130
      y: 220
    - x: 410
      y: 220
      type: link
      path: /Applications

linux:
  target:
    - AppImage
  icon: build/icon.png
  category: Game
  artifactName: '${productName}-${version}-linux.${ext}'

Building

Add the build script to package.json:

  "scripts": {
    "build": "vite build && electron-builder",
    "build:win": "vite build && electron-builder --win",
    "build:mac": "vite build && electron-builder --mac",
    "build:mac-universal": "vite build && electron-builder --mac --universal",
    "build:lin": "vite build && electron-builder --linux"
  }

  "scripts": {
    "build": "tsc && vite build && electron-builder",
    "build:win": "tsc && vite build && electron-builder --win",
    "build:mac": "tsc && vite build && electron-builder --mac",
    "build:mac-universal": "tsc && vite build && electron-builder --mac --universal",
    "build:lin": "tsc && vite build && electron-builder --linux"
  }

You can then build from your terminal or from GitHub Actions:

Build locally

To build for all platforms, run:

npm run build

To build for a specific platform, run:

npm run build:win   # Windows
npm run build:mac   # macOS
npm run build:lin   # Linux

Output files are written to the release/ folder.

Build with GitHub Actions

GitHub Actions provides hosted runners for Windows, macOS, and Linux, making it easy to build for all platforms from a single workflow. Here’s an example workflow that builds and uploads the artifacts as workflow outputs.

1. Create .github/workflows/build.yml:

   name: Build
   on:
     push:
       branches: [main]
     pull_request:
       branches: [main]
   
   jobs:
     build:
       runs-on: ${{ matrix.os }}
       strategy:
         matrix:
           include:
             - os: windows-latest
               script: build:win
               ext: exe
             - os: macos-latest
               script: build:mac
               ext: dmg
             - os: macos-latest
               script: build:mac-universal
               ext: dmg
             - os: ubuntu-latest
               script: build:lin
               ext: AppImage
       steps:
         - uses: actions/checkout@v4
         
         - name: Set up Node.js
           uses: actions/setup-node@v4
           with:
             node-version: 24
             cache: 'npm'
             
         - name: Install dependencies
           run: npm ci
           
         - name: Build
           run: npm run ${{ matrix.script }}
           env:
             CSC_IDENTITY_AUTO_DISCOVERY: false 
             
         - name: Upload artifact
           uses: actions/upload-artifact@v4
           with:
             name: launcher-${{ matrix.os }}
             path: release/*.${{ matrix.ext }}

2. Commit and push to GitHub. The workflow will run automatically, and you can download the artifacts from the workflow run page.

Code signing

Without a code signing certificate, Windows will display a SmartScreen warning and macOS will refuse to open the app.

win:
  certificateFile: certs/my-certificate.pfx
  certificatePassword: '${env.CSC_KEY_PASSWORD}'

Uploading to EML AdminTool

After a successful build, upload the output to EML AdminTool to enable auto-updates for your players. For each platform you support, three files are required.

Go to EML AdminTool > Bootstraps, click the edit button, upload the files for each platform, and save. Players will receive the update the next time they start the launcher.

See Bootstraps in the EML AdminTool documentation and Bootstrap in the EML Lib reference for the full flow.

Troubleshooting

“Cannot create symbolic link” on Windows — Enable Developer Mode: Settings > System > Advanced > Developer Mode.

Antivirus false positives — Unsigned executables are frequently flagged by heuristic scanners. Submit your .exe to Microsoft for analysis, or invest in a code signing certificate (EV or OV) to eliminate the warning permanently.