Examine source code of PiffMusic

{
  "manifest_version": 2,
  "name": "PiffMusic",
  "version": "0.4",
  "description": "Scrapes youtube music for now playing information and sends to local webhook.",
  "icons": {
    "48": "icons/stuxpup.png",
    "96": "icons/stuxpup.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://music.youtube.com/*"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "http://localhost:8080/*",
    "http://localhost:17890/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "stux@stux.ai",
      "strict_min_version": "58.0"
    }
  }
}