Examine source code of Magnetic2

{
  "manifest_version": 2,
  "name": "Magnetic",
  "version": "2.0.0",
  "description": "Open all magnet links in all tabs with a single click!",
  "applications": {
    "gecko": {
      "id": "jid1-U7EWb7p80cgAVw@jetpac2"
    }
  },
  "icons": {
    "18": "data/icon18.png",
    "32": "data/icon32.png",
    "36": "data/icon36.png",
    "64": "data/icon64.png"
  },
  "background": {
    "scripts": [
      "magnetic.js"
    ]
  },
  "browser_action": {
    "default_icon": {
      "18": "data/icon18.png",
      "32": "data/icon32.png",
      "36": "data/icon36.png",
      "64": "data/icon64.png"
    },
    "default_title": "Magnetic"
  },
  "permissions": [
    "<all_urls>",
    "notifications"
  ]
}