Examine source code of WebSerial for Firefox

{
  "manifest_version": 2,
  "name": "WebSerial for Firefox",
  "version": "0.5.0",
  "browser_specific_settings": {
    "gecko": {
      "id": "webserial@kuba2k2.github.io"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "*://*/*"
      ],
      "js": [
        "dist/webserial.content.js"
      ],
      "all_frames": true,
      "run_at": "document_start"
    }
  ],
  "background": {
    "scripts": [
      "dist/webserial.background.js"
    ],
    "persistent": true,
    "type": "module"
  },
  "permissions": [
    "*://*/*",
    "nativeMessaging",
    "storage"
  ],
  "content_security_policy": "default-src 'self' 'unsafe-inline'; script-src 'self' http://localhost:8097; connect-src 'self' ws://localhost:8097"
}