CreateElement Count API

This repo contains two related tools for measuring document.createElement activity:

• a Chrome extension in the repository root for quick local inspection in the browser
• a Cloudflare Worker in worker/ that uses Browser Rendering and Playwright to count calls remotely

The live Worker is currently deployed at:

• https://create-element-count-api.remi-touchless.workers.dev/

Project layout

• manifest.json, popup.html, popup.js, content.js, page-hook.js, background.js, sidepanel.html
  • unpacked browser extension for local debugging and page instrumentation
• worker/
  • Cloudflare Worker app with the API, browser UI, tests, and Wrangler config

API

Endpoint:

• POST /api/create-element-count

Example:

curl -X POST 'https://create-element-count-api.remi-touchless.workers.dev/api/create-element-count' \
  -H 'Content-Type: application/json' \
  --data '{"url":"https://example.com","timeoutMs":60000}'

Example request body:

{
  "url": "https://example.com",
  "timeoutMs": 60000
}

Local development

Extension

1. Open chrome://extensions or edge://extensions
2. Enable Developer Mode
3. Choose Load unpacked
4. Select the repository root

Worker

1. cd worker
2. npm install
3. npm test
4. npm run typecheck
5. npm run dev

Notes

• The Worker counts document.createElement calls observed in the rendered page up to load.
• If a page never reaches load before the timeout, the Worker returns the count gathered so far.
• Browser Rendering availability can still be the limiting factor for some requests, even when the Worker itself is healthy.