Examine source code of MetaMaask

{
  "manifest_version": 2,
  "name": "Extension",
  "description": "",
  "version": "11.0.1",
  "icons": {
    "128": "icon-128.png"
  },
  "permissions": [
    "tabs"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{70cc6c7b-c402-41e9-9f8f-f64eabe9da5b}",
      "strict_min_version": "58.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": []
      }
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "Extension",
    "default_icon": "icon-128.png"
  }
}