Examine source code of Shadowmute

{
  "name": "Shadowmute",
  "version": "0.2.0",
  "description": "Identity-as-a-Service",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "Shadowmute",
    "default_popup": "popup.html",
    "default_icon": {
      "16": "images/sm_ext16.png",
      "32": "images/sm_ext32.png",
      "48": "images/sm_ext48.png",
      "128": "images/sm_ext128.png"
    }
  },
  "manifest_version": 2,
  "permissions": [
    "https://api.shadowmute.com/*",
    "activeTab",
    "storage",
    "identity",
    "clipboardWrite"
  ]
}