Examine source code of AgilCTC

{
  "manifest_version": 2,
  "author": "LINKSIP",
  "name": "AgilOFFICE Click To Call",
  "short_name": "AgilCTC",
  "description": "AgilOFFICE Click To Call pour Firefox",
  "version": "3.7.0",
  "icons": {
    "16": "images/call.png",
    "24": "images/agilctc.png",
    "48": "images/icon48.png",
    "128": "images/icon128.png"
  },
  "options_ui": {
    "page": "options/options.html",
    "browser_style": true
  },
  "permissions": [
    "contextMenus",
    "notifications",
    "storage",
    "cookies",
    "tabs",
    "identity",
    "https://ctc.agiloffice.fr/",
    "http://*.agiloffice.fr/",
    "https://cti2.agiloffice.fr:83/",
    "https://*.agiloffice.fr/"
  ],
  "web_accessible_resources": [
    "*.css",
    "libs/*",
    "images/*.png",
    "images/*.jpg",
    "images/*.svg",
    "libs/jquery-3.4.1.min.js",
    "libs/jquery-migrate-3.1.0.js"
  ],
  "content_security_policy": "script-src 'self'; object-src 'self'",
  "background": {
    "scripts": [
      "libs/tools.js",
      "libs/jquery-3.4.1.min.js",
      "libs/jquery-migrate-3.1.0.js",
      "config.js",
      "libs/socket.io.min.js",
      "libs/juggernaut.js",
      "libs/logger.js",
      "user.js",
      "agil-ws.js",
      "event_handler.js",
      "notification.js",
      "supervision.js",
      "popup/popup_handler.js",
      "background.js"
    ]
  },
  "browser_action": {
    "default_icon": {
      "19": "images/agilctc19x19.png",
      "38": "images/agilctc38x38.png"
    },
    "default_title": "AgilCTC(by Linksip)",
    "default_popup": "popup/popup.html"
  },
  "sidebar_action": {
    "default_title": "AgilCTC",
    "default_panel": "popup/popup.html",
    "default_icon": "images/agilctc38x38.png"
  }
}