dev3000

Captures your web app's complete development timeline - server logs, browser events, console messages, network requests, and automatic screenshots - in a unified, timestamped feed for AI debugging.

Quick Start

pnpm install -g dev3000
dev3000

AI Integration

You should connect claude code or any AI tool to the mcp-server to have it issue commands to the browser.

claude mcp add dev3000 http://localhost:3684/api/mcp/mcp

Then issue the following prompt:

Use dev3000 to debug my app

What it does

Creates a comprehensive log of your development session that AI assistants can easily understand. When you have a bug or issue, Claude can see your server output, browser console, network requests, and screenshots all in chronological order.

The tool monitors your app in a real browser and captures:

• Server logs and console output
• Browser console messages and errors
• Network requests and responses
• Automatic screenshots on navigation, errors, and key events
• Visual timeline at http://localhost:3684/logs

Logs are automatically saved with timestamps in /var/log/dev3000/ (or temp directory) and rotated to keep the 10 most recent per project. The current session is always symlinked to /tmp/d3k.log for easy access.

MCP Integration Notes

The MCP server at http://localhost:3684/api/mcp/mcp supports the HTTP prototcol (not stdio) as well as the following commands for advanced querying:

• read_consolidated_logs - Get recent logs with filtering
• search_logs - Regex search with context
• get_browser_errors - Extract browser errors by time period
• execute_browser_action - Control the browser (click, navigate, screenshot, evaluate, scroll, type)

Cursor:

{
  "mcpServers": {
      "dev3000": {
          "type": "http",
          "url": "http://localhost:3684/api/mcp/mcp"
      }
  }
}

Using the Chrome Extension vs Playwright

dev3000 supports two monitoring modes:

Default: Playwright Browser Automation

By default, dev3000 launches a Playwright-controlled Chrome instance for comprehensive monitoring.

Alternative: Chrome Extension

For a lighter approach, install the dev3000 Chrome extension to monitor your existing browser session.

Installing the Chrome Extension

Since the extension isn't published to the Chrome Web Store, install it locally:

1. Open Chrome and navigate to chrome://extensions/
2. Enable "Developer mode" (toggle in top-right corner)
3. Click "Load unpacked"
4. Navigate to your dev3000 installation directory and select the chrome-extension folder
5. The extension will now monitor localhost tabs automatically

Using with --servers-only

When using the Chrome extension, start dev3000 with the --servers-only flag to skip Playwright:

dev3000 --servers-only

Comparison

Feature	Playwright (Default)	Chrome Extension
Setup	Automatic	Manual install required
Performance	Higher resource usage	Lightweight
Browser Control	Full automation support	Monitoring only
User Experience	Separate browser window	Your existing browser
Screenshots	Automatic on events	Manual via extension
Best For	Automated testing, CI/CD	Development debugging

Options

dev3000 [options]

  -p, --port <port>         Your app's port (default: 3000)
  --mcp-port <port>         MCP server port (default: 3684)
  -s, --script <script>     Package.json script to run (default: dev)
  --servers-only            Run servers only, skip browser launch (use with Chrome extension)
  --profile-dir <dir>       Chrome profile directory (default: /tmp/dev3000-chrome-profile)

Examples:

# Custom port
dev3000 --port 5173

# Use with Chrome extension (no Playwright)
dev3000 --servers-only

# Custom profile directory
dev3000 --profile-dir ./chrome-profile

---

Made by elsigh

Contributing

We welcome pull requests (PRs) from the community!

Before submitting a PR:

• Pull the latest changes from main.
• Run scripts/canary.sh to test your feature locally and verify what is already in the canary build.
• Tip dev3000 --version to verify you're on the canary locally
• FYI .husky/pre-commit.sh runs pnpm format to apply biome.json rules to all code
• Please run and test the canary build locally to avoid duplicating work that may already be done.