Examine source code of FetchGate

{
  "manifest_version": 2,
  "name": "FetchGate",
  "version": "0.3.5",
  "description": "Bridge an external process to a live browser tab - run authenticated fetch() calls or arbitrary JavaScript inside the tab, inheriting its full session state.",
  "permissions": [
    "nativeMessaging",
    "notifications",
    "storage",
    "activeTab",
    "tabs",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": true
  },
  "icons": {
    "16": "icon-16.svg",
    "32": "icon-16.svg",
    "48": "icon.svg",
    "96": "icon.svg",
    "128": "icon.svg"
  },
  "browser_action": {
    "default_title": "FetchGate",
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icon-16.svg",
      "32": "icon-16.svg",
      "48": "icon.svg"
    }
  },
  "commands": {
    "toggle-arm": {
      "suggested_key": {
        "default": "Ctrl+Shift+F"
      },
      "description": "Arm or disarm the current tab"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "fetchgate@localhost",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": []
      }
    }
  }
}