Whispering

Epicenter Local-first apps over a store you own. A store's whole data set is one CRDT document on your machine, complete enough to work with the network off. Sign in on a second device and the two converge. No server holds the only copy, and no app owns your storage. Honeycrisp, a local-first notes app, is the app built on it today. Run the apps freely under AGPL-3.0-or-later. What that means.

The Store | Status | Trust | Repo Map | Development | License

The Store

The hard problem with local-first apps is synchronization. If each device has its own SQLite file, how do you keep them in sync?

Epicenter's answer: a database is one Yjs document, replayed in full before any handle exists, and the surface over it is synchronous. A read is a property access, not a round trip, so nothing is awaited and nothing needs cache invalidation or race protection. The rich half is in there too: a row's node is a nested type on the row, not a second document with an address of its own.

A store definition describes durable data. openLocal acquires its Local store; openPersonal acquires a Personal store for an explicitly supplied account. Applications compose these stores with any other resources they need. Constructing a definition opens no storage and captures no account. It is release-local and never migrates your data. A row it cannot read is reported beside the rows it can, with the reason and the raw values intact, and an ordinary write repairs it.

The node at body merges per character. Declare its codec with body: plainText() and reach it with data.tables.notes.body(note.id); Epicenter never looks inside. The database document's kv/tables: shape is recorded in and its collapse to one document in [ADR-0295](docs/adr/0295-a-database-is-one-yjs-document-and-a-row-holds-its-rich-content.md).

Sync is one Cloudflare Durable Object per (account, application). Being signed in on two devices is the entire sharing model: nothing is paired, invited, or approved.

Status

Store-backed apps run as a desktop SPA in a WebView, over a store the client owns. A host serves bundles and brokers credentials; it owns no application data. A hosted web runtime with a host-owned replica is refused, and so are third-party installed apps, for now.

[Honeycrisp](apps/honeycrisp) is a standalone desktop notes app over native Markdown files. Its rich-text editor keeps a local draft and undo history; saved files and ordinary Git hold the durable data.