Examine source code of etherDNS

{
  "manifest_version": 2,
  "name": "Blockchain DNS",
  "short_name": "B-DNS",
  "version": "1.0.12",
  "description": "Resolves domains from decentralized blockchain name systems using BDNS public web API. Currently supported TLDs are: .bit (Namecoin), .lib .bazar .coin .emc (Emercoin), .bbs .chan .cyb .dyn .geek .gopher .indy .libre .neo .null .o .oss .oz .parody .pirate (OpenNIC).",
  "icons": {
    "16": "icon-16.png",
    "24": "icon-24.png",
    "32": "icon-32.png",
    "64": "icon-64.png",
    "128": "icon-128.png"
  },
  "browser_action": {
    "browser_style": false,
    "default_icon": {
      "16": "icon-16.png",
      "24": "icon-24.png",
      "32": "icon-32.png",
      "64": "icon-64.png",
      "128": "icon-128.png"
    }
  },
  "background": {
    "scripts": [
      "common.js",
      "cache.js",
      "bdns.js"
    ]
  },
  "permissions": [
    "webRequest",
    "webRequestBlocking",
    "proxy",
    "notifications",
    "alarms",
    "tabs",
    "https://bdns.at/*",
    "https://bdns.by/*",
    "https://bdns.co/*",
    "https://bdns.im/*",
    "https://bdns.io/*",
    "https://bdns.link/*",
    "https://bdns.nu/*",
    "https://bdns.pro/*",
    "https://b-dns.se/*",
    "*://*.bit/*",
    "ftp://*.bit/*",
    "*://*.lib/*",
    "ftp://*.lib/*",
    "*://*.emc/*",
    "ftp://*.emc/*",
    "*://*.bazar/*",
    "ftp://*.bazar/*",
    "*://*.coin/*",
    "ftp://*.coin/*",
    "*://*.bbs/*",
    "ftp://*.bbs/*",
    "*://*.chan/*",
    "ftp://*.chan/*",
    "*://*.cyb/*",
    "ftp://*.cyb/*",
    "*://*.dyn/*",
    "ftp://*.dyn/*",
    "*://*.geek/*",
    "ftp://*.geek/*",
    "*://*.gopher/*",
    "ftp://*.gopher/*",
    "*://*.indy/*",
    "ftp://*.indy/*",
    "*://*.libre/*",
    "ftp://*.libre/*",
    "*://*.neo/*",
    "ftp://*.neo/*",
    "*://*.null/*",
    "ftp://*.null/*",
    "*://*.o/*",
    "ftp://*.o/*",
    "*://*.oss/*",
    "ftp://*.oss/*",
    "*://*.oz/*",
    "ftp://*.oz/*",
    "*://*.parody/*",
    "ftp://*.parody/*",
    "*://*.pirate/*",
    "ftp://*.pirate/*",
    "*://*.ku/*",
    "ftp://*.ku/*",
    "*://*.te/*",
    "ftp://*.te/*",
    "*://*.ti/*",
    "ftp://*.ti/*",
    "*://*.uu/*",
    "ftp://*.uu/*",
    "*://*.fur/*",
    "ftp://*.fur/*"
  ],
  "homepage_url": "https://blockchain-dns.info",
  "applications": {
    "gecko": {
      "strict_min_version": "55.0a1"
    }
  },
  "developer": {
    "name": "Blockchain-DNS.info",
    "url": "https://blockchain-dns.info"
  }
}