Examine source code of Copy On Select 2

{
  "name": "Copy On Select 2",
  "description": "A productivity tool which copies selected text to the clipboard automatically",
  "homepage_url": "https://sr.ht/~jschmidt/copy-on-select-2",
  "version": "2.9",
  "browser_specific_settings": {
    "gecko": {
      "id": "{dd97d42c-6560-4fb2-8db4-bf340824fde0}",
      "strict_min_version": "78.0"
    }
  },
  "icons": {
    "32": "copy-on-select-2-32.png",
    "64": "copy-on-select-2-64.png",
    "128": "copy-on-select-2-128.png"
  },
  "permissions": [
    "storage",
    "clipboardWrite"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "common.js",
        "copy-on-select.js"
      ],
      "all_frames": true,
      "run_at": "document_idle"
    }
  ],
  "background": {
    "scripts": [
      "common.js",
      "background.js"
    ],
    "persistent": false
  },
  "options_ui": {
    "page": "options.html"
  },
  "manifest_version": 2
}