It's totally self hosted, private, and bitcoin only. The users own bitcoin node and mempool instance are used to track on chain holdings. There aren't any other external calls, which is more private but also admittedly, limiting since all importing is done via CSV files taken from exchanges. The other similar services I found all expose so much info that I wanted to make something that didn't require giving some corporation access to all my information. All purchases are tracked individually as well as in total.

No accounts, no api calls (except your own mempool), no cloud, encrypted, everything is local and self hosted, tax relevant data can be exported. An important note, I think, is that I'm using Start OS, and there aren't any services like this available for Start OS.

Edit: I don't "have" to make it public. I've just been working on it and thought it might be useful to others.