Examine source code of BroTab

{
  "description": "Control your browser's tabs from command line",
  "manifest_version": 2,
  "name": "BroTab",
  "version": "1.4.0",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "icons": {
    "128": "brotab-icon-128x128.png"
  },
  "permissions": [
    "nativeMessaging",
    "tabs",
    "activeTab",
    "<all_urls>"
  ],
  "applications": {
    "gecko": {
      "id": "brotab_mediator@example.org",
      "strict_min_version": "50.0"
    }
  }
}