Debug Chrome, Node.js and Electron via CDP

Turn them on

Choose View › Enable Network Targets.
Use the + next to Network Targets in the sidebar to add a host:port, for example localhost:9229.
Select a page or process: the DevTools open on the right.

Preset are localhost:9229 and localhost:9333. Port 9222 belongs to Tapscope’s own CDP endpoint, so use another port for your targets. Tapscope checks every address every few seconds and shows it as offline when nothing answers.

Start Chrome with a debug port

Chrome needs its own profile folder when it runs with a debug port:

"/Applications/Google Chrome.app/Contents/MacOS/Google Chrome" --remote-debugging-port=9229 --user-data-dir=/tmp/tapscope-chrome

Its tabs appear under Chrome with their titles. The context menu offers Reload, Bring to Front, Close Tab, Open New Tab…, Copy URL and Copy CDP URL.

Node.js

node --inspect=9230 app.js

Add localhost:9230 as a network target. Node.js processes open in the DevTools for Node, with Console, Sources, Memory and Performance.

Electron

Start the app with a debug port for its windows (--remote-debugging-port=9333) and, for the main process, --inspect=9230. Both ports can be added as network targets.

config.json

The list is stored in ~/.tapscope/config.json and can be edited there while the app is closed:

{
  "devices": {
    "enableNetworkTargets": true,
    "networkTargets": ["localhost:9229", "localhost:9333"]
  }
}

Security

To debug a machine elsewhere, forward its port through SSH instead and add the local end:

ssh -L 9229:localhost:9229 user@build-host

Tapscope’s own endpoint on port 9222 only listens on 127.0.0.1.

Network targets