api — pure Java interfaces and data models; everything is asynchronous.common — platform-independent logic: the core provider plus the SQLite, MySQL, and remote API database implementations.platforms — thin plugin entrypoints for PaperMC, SpigotMC, and FoliaMC that host the provider, manage extensions, and ship as shaded plugin jars.config.yml where you pick and tune the storage engine.db.type selects the backend: sqlite, mysql, or api.plugins/MCBackpack by default.