Examine source code of MetaMask Flask

{
  "author": "https://metamask.io",
  "background": {
    "page": "background.html",
    "persistent": true
  },
  "browser_action": {
    "default_icon": {
      "16": "images/icon-16.png",
      "19": "images/icon-19.png",
      "32": "images/icon-32.png",
      "38": "images/icon-38.png",
      "64": "images/icon-64.png",
      "128": "images/icon-128.png",
      "512": "images/icon-512.png"
    },
    "default_title": "MetaMask",
    "default_popup": "popup.html"
  },
  "commands": {
    "_execute_browser_action": {
      "suggested_key": {
        "default": "Alt+Shift+M",
        "windows": "Alt+Shift+M",
        "mac": "Alt+Shift+M",
        "chromeos": "Alt+Shift+M",
        "linux": "Alt+Shift+M"
      }
    }
  },
  "content_scripts": [
    {
      "matches": [
        "file://*/*",
        "http://*/*",
        "https://*/*"
      ],
      "js": [
        "scripts/contentscript.js",
        "scripts/inpage.js"
      ],
      "run_at": "document_start",
      "all_frames": true
    },
    {
      "matches": [
        "*://connect.trezor.io/*/popup.html*"
      ],
      "js": [
        "vendor/trezor/content-script.js"
      ]
    }
  ],
  "default_locale": "en",
  "description": "__MSG_appDescription__",
  "icons": {
    "16": "images/icon-16.png",
    "19": "images/icon-19.png",
    "32": "images/icon-32.png",
    "38": "images/icon-38.png",
    "48": "images/icon-48.png",
    "64": "images/icon-64.png",
    "128": "images/icon-128.png",
    "512": "images/icon-512.png"
  },
  "manifest_version": 2,
  "name": "__MSG_appNameFlask__",
  "optional_permissions": [
    "clipboardRead"
  ],
  "permissions": [
    "storage",
    "unlimitedStorage",
    "clipboardWrite",
    "http://*/*",
    "https://*/*",
    "ws://*/*",
    "wss://*/*",
    "activeTab",
    "webRequest",
    "webRequestBlocking",
    "*://*.eth/",
    "notifications",
    "identity",
    "cookies"
  ],
  "short_name": "__MSG_appNameFlask__",
  "externally_connectable": {
    "matches": [
      "http://*/*",
      "https://*/*"
    ],
    "ids": [
      "*"
    ]
  },
  "version": "13.34.1.150",
  "applications": {
    "gecko": {
      "id": "webextension-flask@metamask.io"
    }
  }
}