AI-native Office surfaces for the browser, backed by deterministic native automation.

Edit documents, Markdown, spreadsheets, presentations, and PDFs inside your product.
Keep persistence, identity, collaboration, authorization, and AI in your host application.

Playground · Documentation · Quick start · Editors · Automation · Architecture · Contributing

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A3S Office is an open-source Office engine for product teams that need rich browser editing and agent-ready file automation without adopting an A3S backend. It ships complete editor surfaces, typed host contracts, browser file workflows, and a separate Rust automation plane.

• Embed complete editors through React, Vue 3, Web Components, or the framework-neutral Core API.
• Keep format-native behavior instead of forcing every file through one lowest-common-denominator model.
• Own the product boundary: your application controls content, storage, permissions, collaboration, and model providers.
• Automate deterministically through the native CLI, standard MCP server, or packaged Office Skill.

See it working

The images below are committed visual-regression baselines from the real Playground, not conceptual mockups.

Spreadsheet — workbook editing and formula workflows	Presentation — structured slides, objects, and presenter flows
Markdown — GFM source and synchronized preview	PDF — PDFium rendering, forms, annotations, and save

Why A3S Office

• Product-native UI — Complete Office-style surfaces with no required backend, account system, or storage model.
• Accessible responsive shell — Compact sidebars, slide navigation, AI panes, responsive chart inspectors, dialogs, menus, and popovers share bounded keyboard navigation, background isolation, topmost Escape handling, and focus restoration. Persistent desktop navigation and the temporary phone drawer keep separate open states, so live breakpoint changes never turn a desktop sidebar into an unexpected blocking modal or steal focus from the workspace. Shared color palettes expand to an eight-column touch layout on phones while preserving spatial arrow-key navigation.
• Editor-scoped zoom — Status controls and Ctrl/Cmd + mouse-wheel gestures share each surface's bounded zoom model without changing the host browser's page scale.
• Predictable state — Controlled content values, typed callbacks, explicit file actions, conflict-aware document edits, and one document typography baseline across editing, preview, and PDF rendering. Word editing and read-only preview retain the same canonical TipTap tree, while browser PDF export captures that same Worker/WASM page layout instead of rebuilding content from compatibility HTML. Caption numbering and cross-reference validity also update in that same transaction graph, including a truthful missing-target state after deletion.
• Framework choice — React components, Vue 3 adapters, Custom Elements, and a framework-neutral Core API over the same engine.
• Responsive computation — Lazy editor chunks, cancellable Workers, CSS-compatible font-weight matching, Rust WebAssembly layout and calculation, and PDFium rendering.
• AI without UI scraping — Typed agent ports and host-defined selection actions receive structured context and editing commands.
• Automation outside the browser — The native Rust CLI, standard MCP server, and Office Skill share bounded mutation contracts.

Quick start

Try the product locally

Node.js 20+, Bun 1.3+, and Rust 1.85+ are required.

git clone https://github.com/A3S-Lab/Office.git
cd Office
bun install --frozen-lockfile
bun run playground

Then open the local URL printed by the development server. For a zero-install tour, use the live Playground.

Embed a controlled React editor

Install the public package with its React peers:

bun add @a3s-lab/office react react-dom

Import the stylesheet once, give the editor an explicit-height host, and store the complete value emitted by onChange:

import { useState } from 'react';
import type { DocumentContent } from '@a3s-lab/office/core';
import { DocumentEditor } from '@a3s-lab/office/react';
import '@a3s-lab/office/styles.css';

const initialContent: DocumentContent = {
  type: 'document',
  html: '<h1>Project brief</h1><p>Start editing here.</p>',
  pageSize: 'a4',
  pageColor: '#ffffff',
};

export function ProjectBrief() {
  const [content, setContent] = useState(initialContent);

  return (
    <main style={{ height: '100dvh', minHeight: 0 }}>
      <DocumentEditor
        content={content}
        onChange={setContent}
        theme="system"
      />
    </main>
  );
}

The editor owns editing, layout, import/export, and browser rendering. The host owns persistence and decides when, where, and how the emitted content is saved.

Export the live Word layout to PDF

Give each mounted document a stable artifactId, then pass the matching, current artifact to downloadArtifactPdf. Export waits for the live pagination surface and crops the physical pages computed by the editor:

import { useState } from 'react';
import {
  createArtifact,
  downloadArtifactPdf,
} from '@a3s-lab/office/core';
import { DocumentEditor } from '@a3s-lab/office/react';

export function DocumentWithPdfExport() {
  const [artifact, setArtifact] = useState(() =>
    createArtifact('blank-document'),
  );

  if (artifact.content.type !== 'document') return null;

  return (
    <main style={{ display: 'flex', height: '100dvh', flexDirection: 'column' }}>
      <button
        type="button"
        onClick={() => void downloadArtifactPdf(artifact)}
      >
        Export PDF
      </button>
      <section style={{ flex: 1, minHeight: 0 }}>
        <DocumentEditor
          artifactId={artifact.id}
          content={artifact.content}
          onChange={(content) =>
            setArtifact((current) => ({
              ...current,
              content,
              revision: current.revision + 1,
              updatedAt: Date.now(),
            }))
          }
        />
      </section>
    </main>
  );
}

The live path preserves automatic page-break decorations, shaped text, table continuations, and page chrome. It currently rasterizes each physical page into the PDF; searchable text and vector output remain future fidelity work.

Choose an entry point

• @a3s-lab/office/react — Lazy React editor components and preload helpers.
• @a3s-lab/office/vue — Vue 3 adapters with v-model:content.
• @a3s-lab/office/web-component — Custom Elements for framework-agnostic UI composition.
• @a3s-lab/office/core — Typed models, templates, import, export, and browser file workflows.
• @a3s-lab/office/styles.css — Shared editor and interaction-system styles.

Copyable React, Vue, and Web Component examples live in the component documentation.

Five format-native surfaces

Each surface keeps a canonical model that matches its file format and user interaction model.

• Document — Pagination, sections, focused page-setup tabs, clean page margins with on-demand header/footer editing, outline navigation with contextual full-text results, keyboard-operated live physical-page raster thumbnails with viewport-bounded capture, and shared virtualized long-document windows for page buttons, heading rows, full-text results, and tracked-revision and anchored-comment review that preserve native scroll distance, sparse current/selection/draft pins, and Home/End reachability; paragraph styles and phone-sized paragraph-spacing and pagination controls with touch targets and exact invoker-focus restoration; stable compact-ribbon edge paging and viewport-bounded list galleries with touch-sized numbering actions, selection-preserving bullet and numbering commands, and explicit Escape-to-invoker focus restoration; grouped bundled, common system, monospace, imported, and host-provided font choices with live typeface previews, independent table layout algorithms, auto, percentage, or pixel preferred widths, left/center/right placement, indentation, table-level cell margins, cell-level margin overrides, and rendered column measurements for autofit tables. One Table Properties dialog presents table, row, column, and cell tabs. It combines preferred width, placement, and indent with selected-row height and pagination, current-column width, and selected-cell vertical alignment and margins. The complete draft commits in one TipTap transaction and one undo record while untouched imported measurements and partial margin inheritance retain their exact source values. Cancel and Escape discard the draft and restore the exact ribbon invoker; compact layouts keep tabs, numeric steppers, and footer actions touch-sized. A contextual Picture Properties workflow combines centimeter width and height, a per-image aspect-ratio lock, inline/square/top-and-bottom wrapping, alignment, text distance, and alternative text. It commits only changed fields in one TipTap history entry, preserves untouched imported dimensions exactly, and retains the image selection and invoker focus after apply, cancel, or Escape on desktop and phone layouts. A reusable table-border pen with all, outside, inside, and individual-edge targets, per-edge DOCX border preservation, and bounded basedOn table-style inheritance with whole-table, banded row or column, first/last row or column, and corner-cell formatting. Conditional fills, borders, bold, italic, underline, strikethrough, fonts, and text colors are materialized before direct table, cell, paragraph, and run formatting. Conditional paragraph alignment, direction, indents, spacing and line rules, pagination rules, and tab stops use the same precedence chain. Theme tint and shade values resolve for table borders and cell fills across edit, preview, and RGB-stable export. Splittable table rows that exceed a full physical page continue at paragraph boundaries with repeated heading rows on every page, viewport-safe comment drafting and focus-preserving citation drafts, tracked changes, notes, pointer- and Shift+F10-accessible host-defined selection menus, and shared edit/preview/PDF typography and page-chrome placement. Editing, read-only preview, and browser PDF export share one live pagination result. Tail edits reuse the stable physical-page prefix, including resolved first/odd/even headers, footers, page numbers, and navigation descriptors. Real DOCX fixtures provide deterministic A3S Test evidence for inherited table styling across edit and preview, a centered 62.5% table with table and cell margin overrides, all four Table Properties tabs at 390 px, exact preservation of untouched cell-margin edges, a complete 390 px Picture Properties flow, and a 120-paragraph row across three physical pages through the final table content and following paragraph. DOCX import/export; PDF export.
• Markdown — GFM source, visual editing, synchronized and resizable split preview, source-native undo/redo with typing coalescing and selection restore, source-aware ribbon formatting and shortcuts, empty-source guidance, task lists, tables, links, images, code, a flat reading surface with a comfortable line length, and keyboard-accessible host-defined selection menus across both editing surfaces. At phone widths, Source and Preview each use the complete workspace instead of being compressed into two stacked panes. Markdown import/export.
• Spreadsheet — Multiple sheets, formulas, dependency-aware recalculation, live selection statistics, an A3S-owned worksheet bar with lifecycle and color controls, safe deletion confirmation, in-place rename validation, a grid-aligned single-row responsive workbook footer that keeps the active worksheet and its actions visible across window and phone-width changes, selection-preserving undo/redo, deterministic Arrow, Enter, Tab, Home, PageUp/PageDown, row, column, and all-cells selection shortcuts, Cmd/Ctrl formatting through root-scoped capture before vendor grid listeners, an editor-owned Cmd/Ctrl+F search bar that finds displayed values, raw values, formulas, and sparse cells without opening browser Find, with a viewport-safe phone layout, touch-sized controls, and exact grid-focus restoration, desktop workbook task panes that become focus-contained phone dialogs with an inert workbook background and exact ribbon-invoker restoration, Shift+F11 creation, Ctrl/Cmd+PageUp/PageDown switching in edit and read-only preview, one shared cell/worksheet context-menu surface with executable shortcut hints that becomes a touch-sized, scrollable bottom action sheet on phones, keyboard-operated cells and sheet tabs, direct type-to-edit, permission-resilient multi-cell cut/copy/paste, clear, F2 editing, and focus-safe Escape behavior, direct font-family, vertical-alignment, text-wrap, number/percent, and decimal controls, charts, validation, protection, comments, and print settings. XLSX, XLS, ODS, and CSV import; XLSX and PDF export.
• Presentation — Typed slide scene graph, multi-selection, groups, object transforms, keyboard-accessible table-size insertion, Shift+F10-accessible native slide and object context actions, guides, comments, transitions, editor-scoped formatting and clipboard shortcuts that restore the selected object, a docked desktop chart inspector that becomes a focus-contained modal surface whenever it overlays the canvas, docked desktop comment review that becomes a readable, touch-sized, focus-contained full-editor modal on phones with dirty-draft cancellation and exact invoker restoration, a dismissible phone slide navigator, a top-aligned phone canvas with a priority-aware status bar, one-step slideshow from the beginning or current slide, keyboard-complete playback, and a responsive presenter view with one navigation strip, current/next context, speaker notes, and a session timer. PPTX import/export; PDF export.
• PDF — PDFium rendering, navigation, search, form filling, annotations, annotation color, opacity, compatible stroke-width controls, history, a scrollable page-thumbnail rail with current-page synchronization and focus-synchronized Arrow/Home/End navigation, bounded rendering for long files, and a dismissible page drawer whose phone trigger stays in the page controls instead of covering PDF content, focus-safe page and search drafts, responsive search-result, navigation, and zoom controls, editor-scoped shortcuts, and a keyboard-operated overflow menu that retains secondary annotation tools and appearance settings on phones. PDF open/save.

Document and Markdown accept public TipTap Extensions. Spreadsheet, Presentation, and PDF expose stable host ports rather than their internal command contexts. Editor engines and large runtime assets load only when that surface is requested.

Controlled by design

A3S Office is headless at the product boundary, not at the UI boundary. The package includes complete toolbars, ribbons, panes, popovers, and dialogs while leaving product infrastructure to the host.

A3S Office owns: editing models and commands; import, export, layout, and rendering; editor UI and responsive interactions; typed selection and agent ports.

Your host owns: persistence and version history; identity, permissions, and collaboration; the application shell and navigation; AI providers, prompts, policy, and request lifecycle.

Document and Markdown selection menus can be replaced with host-defined typed actions. Each action receives an immutable selection snapshot, nearby text, the complete controlled content, and conflict-aware replaceText, insertBefore, insertAfter, and copyText commands. Markdown snapshots also identify whether the source or visual surface owns the selection. Async edits track unrelated visual-editor transactions and fail with stale-selection instead of changing the wrong text. The Playground's open-ended question action enters a focused draft before dispatch, so a host never receives an unfinished “Question:” request; attached context stays available without dominating the assistant surface.

Browser file workflows

The Core API creates typed blank artifacts and performs browser-side import or export without mounting an editor:

import {
  createArtifact,
  createArtifactBlob,
  importOfficeFile,
} from '@a3s-lab/office/core';

const imported = await importOfficeFile(file);
const output = await createArtifactBlob(imported);
const blankDeck = createArtifact('blank-presentation');

Use downloadArtifact to start a browser download or createArtifactBlob when your application owns upload and persistence.

Native automation

The repository also contains a native Rust engine for deterministic reads, validation, mutation, batch operations, exact natural-unit inventories, sibling-isolated semantic previews, screenshots, file watching, and a source-bound exact-layout raster boundary across Office packages. The first layout-authoritative route supports image-only PPTX slides whose single opaque PNG exactly covers the declared slide surface. The optional Rust pdfium feature adds bounded, one-based PDF page inventory and exact page PNGs through an explicit host-supplied PDFium 7881 library. It records media/crop boxes, rotation, physical and pixel geometry, source and engine hashes, and never downloads a runtime or introduces a Browser dependency. Consumers can inspect selected pages from one previously validated complete inventory without rescanning the full document; render still revalidates the immutable source and actual page profile before publication. The same retained inventory now authorizes bounded native PDF text-layer extraction with source-order Unicode, exact UTF-8/UTF-16 ranges, optional glyph boxes in PDF coordinates, and bounded document outlines with exact page targets. Text and outline calls revalidate the immutable source, reuse inventory authority, and return typed limit or unsupported failures without OCR or Browser access. Richer slides and formats without an authoritative provider remain typed unsupported instead of being relabeled semantic previews. Native DOCX and PPTX table reads also normalize merged cells into one-based logical row and column coordinates, row and column spans, and stable anchor references for covered physical cells.

# Run from the repository root
cargo run -p a3s-office-cli -- validate report.docx --json
cargo run -p a3s-office-cli -- view report.docx outline --json
cargo run -p a3s-office-cli -- set report.docx /body --find Draft --replace Final --json

# Start the standard MCP server
cargo run -p a3s-office-cli -- mcp

CLI, MCP, the typed Rust API, and the packaged Office Skill share the same bounded contracts. They inspect and modify files without launching desktop Office or scraping editor UI.

Read the native engine design, the complete CLI reference, or the published CLI and Skill guide.

Architecture

The browser plane combines controlled editor surfaces, framework adapters, Workers, Rust WebAssembly, and PDFium. The native plane keeps filesystem and OOXML package concerns in a separate Rust core, with a host-injected optional PDFium provider for read-only PDF page evidence. Both planes expose typed contracts; neither requires an A3S backend.

For engine ownership, Worker/WASM boundaries, delivery stages, and performance gates, see Browser editor architecture.

Project status

A3S Office is pre-1.0. Content models and component props are public, but a minor release may still include breaking model changes. Required migrations will be called out in the changelog.

The project targets predictable browser editing and file preservation, not pixel parity with every Microsoft Office or WPS feature. Unsupported OOXML semantics and fidelity gaps remain explicit compatibility boundaries instead of being silently approximated. Track product depth and release evidence in the editor quality roadmap.

Development

Run focused checks from the repository root:

bun install --frozen-lockfile
bun run format:check
bun run lint
bun run typecheck
bun run test
bun run build

Start the integration Playground with bun run playground. The full pull request checklist also covers the Rust workspace, browser bundle budget, and committed visual contracts; see CONTRIBUTING.md.

Documentation

The published website keeps the interactive Playground at its root and builds the searchable Rspress documentation center under /docs/. Simplified Chinese is the stable default, English remains available from the language menu, and the version menu switches between latest and frozen release documentation. Search is scoped to the active language and version. Both surfaces use the same deployment base, so preview, Pages, and fork deployments keep working without hard-coded return URLs.

• Live Playground
• Documentation center
• A3S Office 0.1.0 documentation
• React, Vue, and Web Component integration
• Office CLI and coding-agent Skill
• Browser editor architecture
• Native Office engine
• CLI reference
• Editor quality roadmap
• Changelog

Community and security

Contributions are welcome. Read the contribution guide and Code of Conduct before opening a change. Report suspected vulnerabilities through the private process in SECURITY.md, not through a public issue.

License

A3S Office is available under the MIT License. Bundled PDFium and other third-party assets carry additional notices in THIRD_PARTY_NOTICES.md.