As far as I’m aware, the only self hosted player character builder is the charactermancer in plutonium, the patreon-accessible Foundry VTT plugin made by the 5e.tools folks — but man. My kingdom for a dndbeyond alternative, something self hosted that can take open 5th edition content and allow my players to build and save their character sheets. I don’t suppose I’m just missing something already out there, or are there any projects I should be following?
https://www.dungeonmastersvault.com/
Not self hosted but I believe it is open source. Their discord has content packs that cover all officially released content.