Dev Server Autoopen

Method 1 (CLI): Add --open flag to dev script in package.json Method 2 (Custom Server): Use open package after server starts Environment Control: Use BROWSER=none to disable

Create React App (CRA)

• Set BROWSER=true in .env.local
• Set BROWSER=chrome for specific browser
• Set BROWSER=none to disable

Vue CLI

File: vue.config.js

• Set devServer.open: true
• Set devServer.open: 'chrome' for specific browser

Angular

File: angular.json

• Set serve.options.open: true
• Set specific browser in configuration

Remix

• Add --open flag to dev script
• Or use open package after server

SvelteKit

File: svelte.config.js

• Set kit.devServer.open: true

Astro

File: astro.config.mjs

• Set server.open: true

Nuxt

File: nuxt.config.ts

• Set devServer.open: true

Webpack Dev Server

File: webpack.config.js

• Set devServer.open: true

Script Usage

Python Browser Opener (Included)

This skill includes a cross-platform Python script for opening browsers automatically.

Location: scripts/open_browser.py

Usage:

python scripts/open_browser.py              # Opens http://localhost:3000
python scripts/open_browser.py 5173         # Opens http://localhost:5173
python scripts/open_browser.py 8080 /admin  # Opens http://localhost:8080/admin

Features:

• Cross-platform (Windows, macOS, Linux)
• Waits for server to be ready before opening
• Respects BROWSER=none and CI=true environment variables
• Python 3.6+ compatible, no dependencies
• Handles common dev server ports

Integration Examples:

{
  "scripts": {
    "dev": "vite & python .claude/skills/dev-server-autoopen/scripts/open_browser.py 5173",
    "dev:next": "next dev & python .claude/skills/dev-server-autoopen/scripts/open_browser.py 3000",
    "dev:custom": "node server.js & python .claude/skills/dev-server-autoopen/scripts/open_browser.py 8080 /dashboard"
  }
}

Concurrent Mode (recommended for better reliability):

{
  "scripts": {
    "dev": "concurrently \"vite\" \"python .claude/skills/dev-server-autoopen/scripts/open_browser.py 5173\"",
    "dev:next": "concurrently \"next dev\" \"python .claude/skills/dev-server-autoopen/scripts/open_browser.py 3000\""
  }
}

Direct Shell Usage:

# Windows
start /B npm run dev & python .claude/skills/dev-server-autoopen/scripts/open_browser.py 3000

# macOS/Linux
npm run dev & python .claude/skills/dev-server-autoopen/scripts/open_browser.py 3000

Disable Opening:

BROWSER=none npm run dev
CI=true npm run dev

Custom Solutions

Using 'open' Package

Install: npm install -D open Usage: Import and call after server starts Cross-platform support for all browsers

Shell Scripts

Create npm script that starts server and opens browser Use OS-specific commands (Windows: start, macOS: open, Linux: xdg-open)

Environment Control

Disable Auto-Open

• Set environment variable: BROWSER=none
• Conditional config: only open in development mode
• User preference: .env.local for per-developer settings

CI/CD Environments

Always disable auto-open in CI/CD pipelines Check for CI environment variable

Browser Selection

Specify Browser

• Chrome: 'chrome' or 'google chrome'
• Firefox: 'firefox'
• Safari: 'safari'
• Edge: 'msedge'

System Default

Use true to open system default browser

Troubleshooting

Port Already in Use

• Server won't start if port occupied
• Auto-open won't trigger
• Solution: Change port or kill existing process

Browser Doesn't Open

• Check browser is installed
• Verify spelling of browser name
• Check file permissions on config
• Try system default (true) instead of specific browser

Opens Wrong Browser

• Specify browser explicitly
• Check system default browser settings
• Use full path to browser executable

Opens Multiple Times

• Ensure only one server running
• Check for duplicate scripts
• Remove multiple auto-open configs

Best Practices

Development

• Enable auto-open in development mode
• Open to specific route when needed
• Use system default browser unless specific browser required

CI/CD

• Always disable in continuous integration
• Set BROWSER=none or CI=true
• Don't rely on auto-open for automated testing

Team Consistency

• Document in README
• Add to .env.example
• Allow per-developer override in .env.local

Performance

• Auto-open adds minimal overhead
• No impact on hot module replacement
• No build time impact

Platform-Specific Notes

Windows

• Use start command for shell scripts
• Browser names: 'chrome', 'firefox', 'msedge'
• WSL requires special configuration

macOS

• Use open command for shell scripts
• Browser paths in /Applications/
• System default works reliably

Linux

• Use xdg-open for system default
• Browser commands: google-chrome, firefox
• May require display server (X11/Wayland)

Quick Reference Table