What happens if I reinstall the app?

Reinstalling Dotvault itself is fine — your projects, settings and snapshot history are stored separately from the app and survive it.

What snapshot history cannot survive is losing the key it was encrypted with. That key is stored via Electron’s safeStorage and protected by your macOS Keychain, so resetting your Keychain or reinstalling macOS loses it, and the history goes with it permanently. Your actual .env files on disk are untouched — they are ordinary files in your project folders — but the versions behind them are gone.

The same reasoning is why history does not follow you to a different machine. There is a fuller answer on what does and does not move to a new Mac.