the primary source of this is annoyingly hard to track down for legislation that passed Congress and was signed by the President.

it turns out that’s because it was part of H.R.815 - “Making emergency supplemental appropriations for the fiscal year ending September 30, 2024, and for other purposes.”

if you want to read the actual text of the law, this PDF starting on page 61.

the gist is that it’s illegal to:

Providing services to distribute, maintain, or update such foreign adversary controlled application (including any source code of such application) by means of a marketplace (including an online mobile application store) through which users within the land or maritime borders of the United States may access, maintain, or update such application.

everyone calls this a “ban on TikTok” and it kinda annoys the shit out of me, because as far as I can tell, the website tiktok.com is probably still going to be available in the US.

what this law actually does is require Google and Apple to remove TikTok from their app stores, for US-based users. and makes them subject to a fine of $5000 per user if they don’t comply.

I’m generally in favor of more regulation of tech companies…but this is a really fucking stupid way to do it.

it might be more complicated than you’re looking for (requires a self-hosted server instead of just a desktop app), but take a look at the ecosystem surrounding Subsonic

Subsonic did some licensing shenanigans, but there’s an actively-maintained GPL3 fork called airsonic-advanced

there’s also alternate implementations, Gonic and Navidrome, that maintain compatibility with the original Subsonic API

because they all work with a common API, there’s a variety of clients that can work with the backend.

I’m also a big fan of Beets for music organization, it’s not tied in to the Subsonic ecosystem so you can use them completely separately if you want. it handles tagging, can fetch lyrics, and can also transcode the library (or an arbitrary subset of it) if you want to send it to a portable device. (not sure if this is what you mean by compatibility)

I currently have Beets organizing everything, run Navidrome on my server pointed at the Beets library directory, then Ultrasonic on my phone, and the Navidrome web interface on my desktop. the combo is especially nice for streaming to my phone - Navidrome will transcode FLAC to Opus on the fly, and Ultrasonic has an option to cache those files locally, and to pre-download them over wifi instead of mobile data. so I have my full collection available on my phone, can stream it from anywhere, and the songs I listen to frequently are already downloaded and I don’t have to waste mobile data, or wait for them to load if I have poor cell signal.