Harfsaz — حرف ساز

The first open-source, AI-native desktop editor for Nastaʿlīq & RTL scripts — Urdu · Persian · Arabic.

Real HarfBuzz complex-script shaping + an LLM writing assistant, in one fast, cross-platform desktop app.

Why · Features · Quick start · Architecture · Roadmap · License

حرف ساز — harf-sāz, "the letter-maker" — a typesetter, one who shapes letters into a page.

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Why Harfsaz

Urdu, Persian, and Arabic desktop publishing has been frozen in time. The incumbent — InPage (1994) — is closed-source, Windows-only, and has no AI. Modern word processors still mangle Nastaʿlīq joining and ligatures. Harfsaz rebuilds this from scratch for 2026: AI in the writing loop from day one, on top of a real HarfBuzz Nastaʿlīq typesetting core.

	InPage (incumbent)	Harfsaz
Era	1994 engine, closed source	Modern, open source (AGPL-3.0)
Scripts	Urdu	Urdu · Persian · Arabic · other RTL
Rendering	Proprietary Nastaʿlīq engine	HarfBuzz / rustybuzz (open)
AI	None	Write · Proofread · Translate · Layout — via Claude
Platform	Legacy Windows	Tauri (Rust + web) — macOS · Windows · Linux

The hard part of RTL DTP — correct Nastaʿlīq shaping (joining, ligatures, bari-ye) — is handled by rustybuzz, the pure-Rust port of HarfBuzz, so the same shaping logic that powers Noto Nastaliq Urdu, Gulzar, and Amiri runs natively, with no C toolchain to fight.

Features

• ✍️ AI writing assistant — compose, continue, rephrase, change tone
• 🔤 Proofreading — Urdu / Arabic spelling & grammar correction
• 🌐 Translate & transliterate — English ↔ Urdu, Roman-Urdu → Nastaʿlīq script
• 🎨 Layout / design AI — headline & caption generation, layout suggestions
• 📷 Scan handwriting (OCR) — attach a photo, scan or PDF of handwritten or printed Urdu/Arabic/Persian and get editable Unicode back, ready to typeset
• 🪶 Real Nastaʿlīq shaping — HarfBuzz/rustybuzz, not browser-approximated
• 🖥️ Cross-platform & tiny — Tauri desktop binary for macOS, Windows, Linux
• 🔒 Your key stays local — the Claude API key is stored on your machine and used from the Rust backend; it is never bundled or sent to any Harfsaz server

All AI runs through Claude (Anthropic API) with a key you supply.

Quick start

# 1. install deps
pnpm install

# 2. run the desktop app (Vite + Tauri)
pnpm app:dev

# 3. add your Claude API key in Settings (stored locally), or via env:
export HARFSAZ_ANTHROPIC_API_KEY=sk-ant-...

# build a distributable
pnpm app:build

Requires Rust (stable) and Node 18+. On first run Cargo fetches the Rust deps. Get a Claude API key at https://console.anthropic.com.

Architecture

harfsaz/
├─ src/                     React + TypeScript frontend
│  ├─ App.tsx               app shell (toolbar · canvas · AI panel)
│  ├─ editor/               DTP page + text-frame views
│  ├─ components/           Toolbar, AiPanel, SettingsDialog
│  ├─ lib/
│  │  ├─ store.ts           document model (pages → text frames)
│  │  └─ tauri.ts           typed bridge to Rust commands
│  └─ styles/global.css
└─ src-tauri/               Rust backend (Tauri 2)
   └─ src/
      ├─ shaping.rs         Nastaʿlīq shaping via rustybuzz/HarfBuzz
      ├─ ai.rs              Claude (Anthropic API) bridge — writing · OCR · more
      ├─ settings.rs        local, on-device settings (incl. API key)
      └─ lib.rs             Tauri command wiring

Editor strategy

• Now: text frames are RTL contenteditable — the browser shapes Noto Nastaliq correctly, giving a usable Urdu/Arabic editor immediately.
• Next: the Rust HarfBuzz shaper (shape_text) drives a canvas/SVG print-grade renderer for pixel-precise justification (kashida) and frame-to-frame text overflow — the InPage-defining DTP features.

Roadmap

• Foundation: Tauri shell, document model, AI panel, Nastaʿlīq shaper wired
• AI writing / proofreading / translation / layout via Claude
• Selection AI menu (rephrase · grammar · caption · define · custom prompt)
• Handwriting/scan OCR → editable Nastaʿlīq text (image or PDF attachment)
• Document save/load (.harfsaz format)
• Canvas/SVG print-grade renderer driven by HarfBuzz output
• Frame linking — text overflow flows frame → frame → page
• Kashida justification (newspaper-grade)
• PDF export with embedded fonts
• Roman-Urdu live transliteration as you type
• Batch OCR — a folder of scans into one document
• First-class Persian & Arabic UI presets

Harfsaz is at an early (v0.x) stage — the core editor and AI features work today; the print-grade renderer and PDF export are in progress. Contributions welcome.

Contributing

Contributions are very welcome — especially from the Urdu / Persian / Arabic developer and typography communities. See CONTRIBUTING.md. Harfsaz uses a lightweight CLA via DCO sign-off (git commit -s); see CLA.md.

License

Harfsaz is dual-licensed:

• Open source: GNU AGPL-3.0. You may use, study, modify, and share Harfsaz freely. If you modify it — including offering a modified version to users over a network — your version must also be released under the AGPL-3.0.
• Commercial: if you want to use Harfsaz in a way the AGPL doesn't allow (e.g. a closed-source or proprietary product), a separate commercial license is available. Contact billing@harfsaz.com.

See COPYRIGHT. The Harfsaz name and logo are trademarks (see TRADEMARKS.md); the bundled Harfsaz Kufi typeface is proprietary and licensed for use in Harfsaz only. All other bundled fonts are OFL-1.1 / Apache-2.0 and the shaping libraries are MIT — see THIRD-PARTY-NOTICES.md.

Copyright © 2024–2026 HarfSaz · https://harfsaz.com