Lekho (লেখো) — Avro Phonetic Bangla Keyboard for macOS

The only Avro Phonetic keyboard built natively for Apple Silicon Macs.

Lekho brings Avro Phonetic-style Bangla (Bengali) typing to Apple Silicon Macs natively (M1, M2, M3, M4, M5) — no Rosetta required. If you used Avro Keyboard on Windows, iAvro on macOS, or OpenBangla Keyboard on Linux, Lekho is your native Apple Silicon alternative.

Download | Website

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Why Lekho?

The existing Bangla keyboard options for macOS each have limitations on Apple Silicon:

• Avro Keyboard (OmicronLab) — Windows-focused, no native macOS build
• iAvro — Intel-only macOS build that runs on Apple Silicon through Rosetta. Apple has announced Rosetta support is being wound down — fully available in macOS 27, then limited to legacy games starting in macOS 28. macOS already shows a deprecation warning on Intel-only input methods.
• OpenBangla Keyboard — Linux only (Qt-based), no macOS port
• macOS built-in Bengali — Apple's own layout, not Avro phonetic

Lekho is built natively for Apple Silicon — no Rosetta required, future-proof as macOS evolves. It works in every app — Safari, Chrome, VS Code, Notes, Spotlight, everywhere.

Features

• Avro Phonetic typing — type ami banglay gan gai → আমি বাংলায় গান গাই
• 150k word dictionary with smart suggestions and autocorrect
• Smart emoji suggestions — type কান্না and get 😢, বাংলাদেশ and get 🇧🇩, right in the candidate panel
• Three typing modes — Phonetic-first (default: your exact spelling by default with the suggestion list still one keypress away), Smart (suggestions, autocorrect, and emoji pick the word for you), or Phonetic-only (pure character-by-character control, no popup). Switch anytime in Settings.
• Native Apple Silicon — ~2.7 MB, instant startup, zero CPU when idle
• Works on all Apple Silicon Macs — MacBook Air, MacBook Pro, iMac, Mac Mini, Mac Studio (M1/M2/M3/M4/M5)
• Works everywhere — built with Apple's InputMethodKit framework
• Completely offline — no internet, no data collection, no telemetry
• Free and open source (MPL-2.0) — no ads, no subscription

Install

Option A — Homebrew (recommended if you have it)

brew install --cask arahim3/lekho/lekho

That single command auto-taps and installs Lekho. Then jump to step 3 below to add the input source.

To update later: brew upgrade --cask lekho. To uninstall: brew uninstall --cask lekho.

Option B — Download the DMG

1. Download the latest .dmg from Releases

2. Open the DMG and double-click Install Lekho.pkg

   macOS may block the installer since Lekho isn't signed with an Apple Developer ID yet. If you see "Install Lekho.pkg" Not Opened, follow these two steps:

   a. Click Done on the warning dialog (do not click "Move to Trash"). The "Open Anyway" option won't appear in System Settings until you do.

   

   b. Open System Settings → Privacy & Security, scroll to the Security section, and click Open Anyway next to "Install Lekho.pkg" was blocked. Then double-click the .pkg again.

   

Final steps (both options)

3. Go to System Settings → Keyboard → Input Sources → Edit, click +, find Lekho, and add it

   If Lekho doesn't appear in the list, log out of your Mac and log back in — macOS sometimes needs this to discover new input methods on first install.

4. Use Globe key or Ctrl+Space to switch to Bangla

Typing modes

Open the Settings tab in the Lekho window to pick how typing behaves:

• Phonetic-first (default) — your exact phonetic spelling is committed by default, but the suggestion list is still one keypress away. Lekho remembers the words you deliberately pick.
• Smart suggestions — dictionary, autocorrect, and emoji pick the best-matching word when you press space.
• Phonetic-only — pure transliteration, no suggestion popup, autocorrect, or emoji.

Changes apply immediately — no restart needed.

Requirements

• macOS 13 (Ventura) or later
• Apple Silicon Mac (M1/M2/M3/M4/M5)

Build from Source

Prerequisites: Rust toolchain, Xcode (for Swift and InputMethodKit).

# Install Rust (if not already)
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
rustup target add aarch64-apple-darwin

# Build
make build

# Install to ~/Library/Input Methods/
make install

# Create distributable .dmg
bash scripts/create_dmg.sh

Architecture

Swift (InputMethodKit)  ←→  Rust Engine (riti) via C FFI

• Rust engine (engine/) — wraps OpenBangla/riti, compiled as a static library
• Swift IMK layer (Lekho/) — subclasses IMKInputController, handles key events, candidate window, and text commits
• No Xcode project — built with swiftc + cargo + shell scripts

Contributing

Contributions are highly welcome! Whether it's reporting a bug, suggesting a feature, or submitting a pull request to improve the Swift or Rust codebases, feel free to get involved.

Credits

Lekho is powered by OpenBangla's riti engine — the same Bengali transliteration engine behind OpenBangla Keyboard on Linux.

Feedback

Found a bug or have a suggestion? Open an issue.

License

MPL-2.0

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Keywords: Avro keyboard Mac, Bangla keyboard macOS, Bengali typing MacBook, Avro phonetic Apple Silicon, অভ্র কিবোর্ড ম্যাক, বাংলা টাইপিং ম্যাক

Maintained by Abdur Rahim