Examine source code of TeamCity Notifier

{
  "manifest_version": 2,
  "name": "TeamCity Notifier",
  "version": "0.0.21",
  "description": "Shows notifications about various events in TeamCity",
  "browser_specific_settings": {
    "gecko": {
      "id": "teamcity-notifier-extension@jetbrains.com"
    }
  },
  "permissions": [
    "storage",
    "notifications",
    "webRequest",
    "webRequestBlocking",
    "background",
    "<all_urls>"
  ],
  "icons": {
    "16": "assets/action-icon-16.png",
    "32": "assets/icon-32.png",
    "48": "assets/icon-48.png",
    "96": "assets/icon-96.png",
    "128": "assets/icon-128.png"
  },
  "browser_action": {
    "default_icon": {
      "16": "assets/action-icon-disabled-16.png",
      "24": "assets/action-icon-disabled-24.png",
      "32": "assets/action-icon-disabled-32.png"
    },
    "default_title": "TeamCity Notifier",
    "default_popup": "dist/popup.html"
  },
  "background": {
    "scripts": [
      "assets/browser-polyfill.js",
      "background.js"
    ],
    "persistent": true
  },
  "content_scripts": [
    {
      "matches": [
        "*://*/*"
      ],
      "all_frames": true,
      "js": [
        "detect/content.js"
      ]
    },
    {
      "matches": [
        "*://*/*"
      ],
      "run_at": "document_start",
      "all_frames": true,
      "js": [
        "assets/browser-polyfill.js",
        "notify/content.js"
      ]
    }
  ],
  "options_ui": {
    "page": "dist/options.html",
    "browser_style": true,
    "chrome_style": true
  },
  "web_accessible_resources": [
    "detect/inject.js",
    "notify/inject.js"
  ]
}