@betteroffice/docx

Framework-free core for the BetterOffice DOCX editor — the Rust engine (OOXML parse/serialize, CRDT editing core, text shaping, pagination) compiled to WebAssembly, plus the display-list, canvas-render, geometry, and accessibility helpers the adapters build on. Layout never touches the DOM: the engine measures every line and pages are replayed onto canvas.

Early (0.0.x). The core surfaces — opening/saving documents, the editor components, collaboration — are settling and unlikely to change shape. Smaller APIs may still move between releases; breaking changes are always listed in the changelog.

bun add @betteroffice/docx

Most apps want the turnkey React component in @betteroffice/docx-react. Reach for this package directly for headless parsing/serialization or when building a custom adapter.

Parse and save

A full round trip: open a .docx, inspect the typed model, write bytes back.

import { readFile, writeFile } from 'node:fs/promises';
import { parseDocx, repackDocx } from '@betteroffice/docx/docx';

const document = await parseDocx(await readFile('contract.docx'));
// document.package: body, styles, numbering, theme, media, headers/footers

const bytes = await repackDocx(document);
await writeFile('contract-out.docx', Buffer.from(bytes));

repackDocx round-trips against the original buffer so untouched parts are preserved; use createDocx for documents built from scratch.

The engine ships as four wasm assets (container, parser, layout, editing core) in dist/generated/. Browsers fetch them lazily behind the async entry points (parseDocx, save, the layout engine, createYrsSession); Node and Bun read them from disk synchronously on first use. No manual init call is required.

Collaboration

Connect the editor's Yrs replica to any reliable binary transport:

import { CollaborationProvider } from '@betteroffice/docx/collaboration';

const provider = new CollaborationProvider(replica, createTransport(), {
  user: { name: "Ada" }, // identity for this peer's remote caret
});
provider.connect();

replica can be a direct YrsSession, the worker-aware adapter returned by createWorkerCollaborationReplica, or the value published by the React editor's collaboration.onReplica callback. The provider speaks Yjs sync-v1; room routing, authentication, awareness, and reconnection policy remain transport concerns. Pass a persisted Yrs update as collaboration.initialUpdate when a React editor joins an existing room so it hydrates the shared history instead of independently importing the same DOCX.

Development

The generated .wasm binaries are intentionally not committed. From the repository root, install wasm-pack 0.15.0 and binaryen, then run bun run build:docx-wasm. Package builds, demo startup, and CI run this step automatically.

Docs: https://betteroffice.dev · Apache-2.0.