OpenBook

A safe space for your notes. OpenBook is a free, open-source (MIT), local-first app for writing and organizing knowledge — where a document isn't just text, it can compute.

Your work lives on your machine first. OpenBook runs as a desktop app that keeps everything in a local database on your own device, so your notes stay yours and the app doesn't phone home or collect anything about how you use it. Want your pages on another device, or shared with other people? Sync is optional — and you can host it yourself. Curious how any of it works? Check out the source on GitHub.

What you can build

Documents that compute. The block editor ships an artifact kit: named inputs (sliders, number steppers, text fields, radio groups, checklists, toggles, locations, action buttons) publish values onto a shared reactive scope, and live blocks compute over it — formulas, charts (line, area, bar, pie, donut, scatter, funnel), and status lights. Assemble a calculator, a picker, or a tiny dashboard out of blocks — collaborative by default, and the interactive HTML export keeps the computation alive offline. A dataflow view (page menu → "Dataflow view") opens the page's reactive wiring as a live node graph in the split pane: inputs flowing into code into charts, values updating as you edit, nodes clicking through to their blocks.

Databases live inside pages. A page can host a database (a Notion-style collection in its own table). Database rows are themselves ordinary pages — each with its own editable document — so a row opens in a split pane for editing. Columns are typed properties, or expr columns that read a row page's live exported reactive value, and every view can filter and sort.

Pages nest. A page can be a child of another (cascading on delete), so the sidebar is a tree and the breadcrumb shows the full path. Inside the editor, a Page or Database block links a child inline — it creates the nested page on the spot and clicking it navigates there.

Deletes are recoverable. Deleting a page is a soft delete: it (and its nested subtree) moves to the Trash, where it can be restored or removed for good. A background cleanup job empties the trash after a configurable retention window (default 30 days).

Tabs are native. Each page lives at its own URL (?page=<id>), so opening a page elsewhere uses the platform: on the web a new browser tab or window, on the desktop a macOS window-tab or a standalone window. A window can also split to show two pages side by side.

It's extensible. Plugins — zips of TypeScript source — add custom blocks, palette commands, and integrations (see PLUGINS.md). Registries can sign packages (Ed25519); the app verifies against keys you trust and badges provenance.

Sharing & sync

OpenBook works fully offline on a single device with nothing to sign up for. When you do want to sync across devices or collaborate, you have two options: run the same server yourself against your own Postgres (see Storage & server), or publish a library to book.cloud, our hosted service. Publishing to book.cloud needs a free account — that's how we keep out abuse and fraud.

Getting started

Important

OpenBook is currently in active development. Please make regular backups of your data while using it.

Download OpenBook from the Releases page.

Alternatively, you can build it from source.

Prerequisites

• Node.JS 18.x or later
• pnpm (pinned via the packageManager field — corepack enable will install it automatically)
• Rust toolchain (for the desktop apps)

Setting up the development environment

1. Download and install the prerequisites.
2. Install dependencies: pnpm install.
3. Build and start developing: pnpm run build.

Storage & server

OpenBook stores documents as pages (UUID + optional name + JSON payload) in Postgres. The server is written in TypeScript and the desktop app and the headless deployment run the exact same code — the desktop bundles it as a self-contained sidecar over an embedded Postgres (PGlite/WASM); a headless deployment runs it against an external Postgres. The web shell, desktop, and server all share types and the HTTP client through @book.dev/sdk.

Packages:

• packages/sdk — shared types + HttpDataClient.
• packages/server — page store + Hono API, backed by PGlite (embedded) or external Postgres. Full architecture and deployment modes documented there.

Run the headless server:

OPENBOOK_DATABASE_URL=postgres://user:pass@host:5432/openbook \
  pnpm --filter @book.dev/server dev

pnpm dev runs the SDK, server (with embedded Postgres), UI, web, and desktop together.

License

OpenBook is released under the MIT License.