Works with the network off
OpenBook keeps your pages on the device, reads and writes them locally, and reaches the network only when you switch sync on.
Reads and writes happen on-device
Pages live in a local database, so opening one is a read from disk. The network is an enhancement. You can keep working on a plane or in a dead zone.
Sync is a switch you flip
Sign in and OpenBook keeps settings and pages in step across devices. Stay signed out and everything stays on the device.
Conflicts merge themselves
OpenBook runs on CRDTs (Yjs). Two people editing the same page, or a device coming back online, reconcile into one document instead of the "which version do you want to keep?" dialog.
Exports stay open
Everything leaves as HTML, PDF or Markdown, including self-contained interactive HTML. Your words and tools travel in formats anything can read.
AI, when you ask
The math runs on your device; the AI waits to be asked.
The work stays where it lives
Pages run on the device. Point AI at a page and it reads what you hand it — nothing streams off in the background.
You choose the engine
Nothing runs until you enable an engine and pick a provider, either a local model or a hosted one. Switch it off and OpenBook is exactly as it was.
Changes arrive as suggestions
You review each one and apply it yourself. AI never rewrites a page on its own.
The same exits apply
Anything AI touches still exports as HTML, PDF or Markdown, and the source is MIT on GitHub. Turning AI on changes nothing about how you get your work out.
Curious how it works under the hood?
The developer site goes deep on the CRDT model, the block format and self-hosting.