The next step up from “only in the browser” is storage on a machine you run: a desktop folder, a small home server, or a NAS. Coffee Server and its Vault sidecar are architected around a root path you choose — your crib, your bytes, your backups to worry about (which is the point).
Instead of your prose living only inside a multinational’s multi-tenant database, files can land under ROOT_DIR or another directory you designate. You can back it up with the same tools you use for photos: Time Machine, Borg, rsync, whatever matches your paranoia level.
A coordinator process on your machine exposes APIs while delegating risky or heavy work to sidecars. Auth at the boundary (Keyman) decides what may touch Vault. That whole story is its own track — start at Coffee Server & the crib stack.
Home network basics (ports, LAN vs WAN) live in Home Cloud — read that if “expose a service safely” still feels fuzzy.