Examine source code of JSloader

{
  "description": "Store JS scripts to be run for a given site",
  "manifest_version": 2,
  "name": "jsloader",
  "version": "2.7resigned1",
  "applications": {
    "gecko": {
      "id": "santiaguzz@gmail.com",
      "strict_min_version": "57.0"
    }
  },
  "background": {
    "scripts": [
      "utils/deps/EventEmitter/EventEmitter.min.js",
      "utils/deps/async.min.js",
      "utils/deps/underscore-min.js",
      "utils/jsloader-utils.js",
      "bg/persistence.js",
      "bg/data_model.js",
      "bg/option_mgr.js",
      "bg/proxy_mgr.js",
      "bg/editor_mgr.js",
      "bg/_data_mgr.js",
      "bg/domain_mgr.js",
      "bg/group_mgr.js",
      "bg/notify_mgr.js",
      "bg/tabs_mgr.js",
      "bg/resource_mgr.js",
      "bg/content_mgr.js",
      "bg/translation_mgr.js",
      "bg/background.js"
    ]
  },
  "page_action": {
    "browser_style": true,
    "default_icon": {
      "16": "fg/icons/Diskette_16.png",
      "32": "fg/icons/Diskette_32.png"
    },
    "default_popup": "fg/page_action/pa.html"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*/*",
        "<all_urls>"
      ],
      "js": [
        "fg/deps/jquery.min.js",
        "utils/deps/bluebird.min.js",
        "utils/jsloader-utils.js",
        "utils/deps/EventEmitter/EventEmitter.min.js",
        "bg/content_api.js",
        "bg/content_script.js"
      ],
      "all_frames": true,
      "run_at": "document_start"
    }
  ],
  "options_ui": {
    "browser_style": true,
    "open_in_tab": true,
    "page": "fg/opt_page/options.html"
  },
  "commands": {
    "add-script-for-tab": {
      "suggested_key": {
        "default": "Alt+Shift+1"
      },
      "description": "Open a new editor window, binded to the currently focused tab."
    },
    "new-group-new-script": {
      "suggested_key": {
        "default": "Alt+Shift+2"
      },
      "description": "Create new group, and binds a new script."
    },
    "open-option-page": {
      "suggested_key": {
        "default": "Alt+Shift+Q"
      },
      "description": "Shows configuration menu."
    }
  },
  "content_security_policy": "script-src 'self' 'unsafe-eval'; object-src 'self'; img-src 'self'",
  "permissions": [
    "storage",
    "tabs",
    "cookies",
    "notifications",
    "<all_urls>",
    "downloads",
    "activeTab",
    "proxy",
    "nativeMessaging"
  ]
}