Examine source code of Wasc Mail

{
  "manifest_version": 2,
  "version": "0.0.1",
  "short_name": "Wasc Mail",
  "name": "Wasc Mail",
  "description": "An extension to create aliases for Wasc Mail",
  "browser_action": {
    "browser_style": true,
    "default_title": "Wasc Mail"
  },
  "background": {
    "scripts": [
      "background.bundle.js"
    ]
  },
  "icons": {
    "128": "img/icon-128.png"
  },
  "permissions": [
    "activeTab",
    "identity",
    "notifications",
    "clipboardWrite"
  ],
  "content_security_policy": "script-src 'self' 'unsafe-eval'; object-src 'self'"
}