Koma Music is a private app for one household. Its only user is the owner of the YouTube account it signs in to, called "you" below.
With your permission, given once through Google's sign-in, it reads your liked songs and your playlists, through the YouTube Data API, so that Koma can play them at home when you ask. When you ask, it marks a song as liked or disliked. It changes nothing else.
It keeps the sign-in token, and nothing else from your account, on the family's home server, readable only by the Koma service. Music is played as it streams and is not stored.
Nothing. Your data is not sold, shared, or used for advertising, and no one else sees it. This site sets no cookies and runs no analytics.
Koma Music's use and transfer of information received from Google APIs adheres to the Google API Services User Data Policy, including the Limited Use requirements.
Remove Koma Music's access at any time in your Google Account, under Third-party apps and services. The token on the home server then stops working, and it can be deleted there too.