Lekh Assistant

Write Nepali without breaking your flow.
_{आफ्नो लय नतोडी नेपाली लेख्नुहोस्।}

A private, native typing assistant for macOS and Windows.
Romanized input becomes deliberate Devanagari suggestions—inside the app where you are already writing.

No browser tab. No copy-and-paste loop. No account required.

v1.0.3 release · verify downloads · known limitations

Most transliteration tools make Nepali a detour: open a website, type, copy, paste, and repeat. Lekh makes Nepali part of the operating system. Select the keyboard once, type naturally in Roman letters, and stay with the thought instead of managing the tool.

Lekh is built around a simple promise: the software may assist your writing, but it must never take authority over it.

• Stay in the app. Lekh installs as a native input method, not a web editor.
• See before committing. Suggestions remain suggestions until you choose.
• Keep your writing private. The v1 typing path works locally, without text telemetry, an account, or a network dependency.
• Preserve the text that should stay Latin. URLs, email addresses, common identifiers, file names, and numbers are guarded from forced conversion.
• Leave safely. Switch to another keyboard at any time, or quit the companion explicitly.

Important

v1.0.3 is an unsigned community preview. The macOS package is ad-hoc signed but not Apple-notarized; the Windows package has no publisher certificate. Gatekeeper or SmartScreen warnings are therefore expected. Download only from the official release links above and compare the file with the published SHA-256 checksums. Lekh never asks you to disable operating-system security globally.

What you get

Capability	v1.0 behavior
Romanized Nepali	Type familiar Latin spellings such as namaste; choose from ranked Devanagari candidates such as नमस्ते.
System integration	Native InputMethodKit input method on macOS; native Text Services Framework text service on Windows.
Candidate control	Inline and popup candidates on macOS; numbered, keyboard/pointer-selectable, Narrator-readable candidates on Windows. Nothing commits merely because it appears.
Local language tools	Bundled dictionary-backed ranking, local explicit-choice memory, and conservative active-token proofread suggestions.
Traditional typing	Traditional → Nepali and Traditional → Romanized on macOS, clearly labeled Beta.
Privacy boundary	No text telemetry in the v1 typing path. Secure or unknown contexts fail closed and clear composition state.
Offline behavior	Typing, suggestions, dictionary ranking, and proofread rules do not require a server or account.

Platform support

Platform	Release target	What ships
macOS	macOS 13 or newer	One universal installer for Apple Silicon and Intel Macs
Windows	Windows 11 x64	x64 installer with 64-bit and 32-bit native text-service support, a local broker, and the companion

Windows ARM64 compiles and passes native tests in CI, but v1.0 does not ship an ARM64 installer because that install lifecycle has not passed the same verification as x64.

Install

End users do not need Node.js, npm, or a developer toolchain.

macOS

1. Download Lekh-Keyboard-Test-Installer.zip.
2. In Finder, double-click the ZIP once. Keep the extracted Lekh Keyboard Test Installer folder intact.
3. Open that folder. Control-click or right-click Lekh Keyboard Test Installer.app, choose Open, then click Open again.
4. Wait for the success message and click OK.
5. Save your work, log out of your Mac, and log back in. macOS can cache a newly installed unsigned input method.
6. Open System Settings → Keyboard. Beside Text Input, click Edit…, then click +.
7. Select Nepali on the left, select Lekh Keyboard on the right, and click Add.
8. Choose Lekh Keyboard from the input-source menu in the menu bar.

If macOS blocks the installer

Use these options in order:

1. Repeat the Finder right-click → Open flow. Do not start with a normal double-click.

2. Open System Settings → Privacy & Security, scroll to Security, and choose Open Anyway for Lekh Keyboard Test Installer.

3. Only if both supported UI paths fail, open Terminal and run this command against the installer app itself:

   xattr -dr com.apple.quarantine "/path/to/Lekh Keyboard Test Installer.app"

   You can drag the installer app into Terminal to insert its exact path. Never run this command on Downloads, your home folder, an entire drive, or any directory broader than this one installer app. Then repeat right-click → Open.

If Lekh is missing from Input Sources

1. Confirm that the installer reported success.
2. Log out and back in; closing System Settings is not enough.
3. Return to System Settings → Keyboard → Text Input → Edit… → + → Nepali.
4. If Lekh is still absent, rerun the installer from the complete extracted folder, then repeat the logout/login step.

Windows

1. Download Lekh-Keyboard-Companion-1.0.3-Setup-x64.exe.
2. Double-click the installer.
3. If Windows says Windows protected your PC, click More info, confirm that the file name is the Lekh installer, and click Run anyway. If Windows provides no Run anyway option, Smart App Control or an organization policy is blocking unsigned software. Do not disable device security globally; this unsigned preview cannot be installed on that PC.
4. Approve the User Account Control prompt. Administrator approval is required because the installer registers a machine-wide Windows text service.
5. Keep the default install folder, click Install, and wait for setup to finish.
6. Open Lekh Keyboard Companion once and confirm that Keyboard registration, Typing service, and Run at sign-in all show Ready.
7. Open Notepad, press Windows key + Space, and choose Lekh Keyboard Nepali. Type namaste; the inline suggestion should show नमस्ते.

Setup adds Lekh to the installing user's Windows input list, but it does not change the default keyboard or switch input sources without the user.

If Lekh is not listed, open Lekh Keyboard Companion → Updates & diagnostics and choose Repair text service. Approve its single UAC prompt, then sign out and back in once if Windows has not refreshed the input list. Reinstall only if the companion reports that a required native file is missing.

If Lekh is selected but typing stays Latin

1. Open Lekh Keyboard Companion → Updates & diagnostics and confirm that Keyboard registration and Typing service both show Ready.
2. If registration needs attention, choose Repair keyboard and approve its UAC prompt.
3. If the service needs attention, choose Restart typing service.
4. Confirm Run at sign-in is enabled, then retry in Notepad before testing Word, a browser, or another editor.
5. If the keyboard was just installed or repaired, sign out and back in once, select it again with Windows key + Space, and retry.

Lekh intentionally passes Latin text through unchanged when its local service is unavailable or when Windows reports a secure or unknown typing context. It never asks users to disable antivirus, SmartScreen, or Smart App Control.

Verify a download before opening it

Download the official SHA256SUMS.txt file, then compare the installer hash.

On macOS:

shasum -a 256 ~/Downloads/Lekh-Keyboard-Test-Installer.zip

On Windows PowerShell:

Get-FileHash "$HOME\Downloads\Lekh-Keyboard-Companion-1.0.3-Setup-x64.exe" -Algorithm SHA256

Type with Lekh

Romanized → Nepali

1. Select Lekh as the current input source.
2. Type a Nepali word with Roman letters—for example, namaste.
3. Review the Devanagari candidates.
4. Choose नमस्ते. If you do not choose a suggestion, Lekh does not silently commit it.

macOS controls

Action	Control
Choose Romanized Nepali	Click the ले menu → Romanized → Nepali
Open the mode chooser	Control + Option + Space
Accept the gray inline completion	Tab or Right Arrow
Open or move through candidates	Down Arrow, then Up/Down
Commit the highlighted candidate	Return
Choose a visible shortcut	Option + 1, 2, or 3
Keep or cancel to raw text	Escape
Turn Lekh off	Click the ले menu → Switch to ABC, or choose another input source

The same ले menu contains Traditional → Nepali (Beta) and Traditional → Romanized (Beta). Their complete physical layout has not been validated by an experienced Traditional typist, so Romanized → Nepali is the recommended v1.0 mode.

Windows controls

Action	Control
Turn Lekh on or switch keyboards	Windows key + Space
Accept the inline ghost suggestion	Tab or Right Arrow
Move through candidates	Up/Down Arrow
Choose a numbered candidate	1–8
Choose with pointer or touch	Click or tap a candidate row
Commit the selected candidate	Space or Enter
Cycle Lekh typing modes	Ctrl + Alt + Space
Choose English letters → Nepali	Ctrl + Alt + 1
Choose Romanized text	Ctrl + Alt + 2
Turn Lekh off	Windows key + Space, then choose another keyboard

To stop the Windows background process completely, open Lekh Keyboard Companion from the Start menu and choose File → Exit Lekh Keyboard Companion. Typing then fails open to unchanged Latin input until you reopen the companion.

Suggestions, dictionary, and proofread

Lekh v1.0 deliberately favors predictable assistance over aggressive automation.

• Candidate ranking combines deterministic transliteration, bundled word and phrase data, and choices you explicitly accepted on this device.
• Personal learning stores candidate choices, not surrounding sentences.
• The bundled dictionary supports ranking and local lookup, but is not presented as an authoritative dictionary with professionally certified definitions for every entry.
• Proofread can offer a Fix candidate for supported active Nepali tokens. It is not a document-wide spelling or grammar checker.
• A missing hint is not a claim that the text is correct. Every correction remains an explicit choice.

Trust is an architecture decision

Lekh does not treat privacy and text safety as marketing settings bolted onto the end. They shape the commit path itself:

flowchart LR
    A["Keys in the current app"] --> B{"Safe, known typing context?"}
    B -- "No or unknown" --> C["Clear composition<br/>Leave host text unchanged"]
    B -- "Yes" --> D["Local deterministic engine"]
    D --> E["Ranked candidates"]
    E --> F{"Did the user choose?"}
    F -- "No" --> G["No commit"]
    F -- "Yes" --> H["Commit selected Devanagari<br/>to the owning context"]

Loading

• Native host boundaries: macOS uses InputMethodKit; Windows uses Text Services Framework. The browser demo is not represented as the system keyboard.
• Secure-field behavior: password and unknown contexts clear local composition and refuse transformation.
• Bounded authority: candidate commits are tied to the active session and owning text context.
• Local IPC: the native input service and companion communicate through versioned local contracts; text is not sent to a web service.
• Reversible preference: explicit choices may improve local ranking, and the user can reset or remove Lekh-owned data.

Read the security policy for reporting a vulnerability.

Engineering evidence, not slogans

The v1.0 release is backed by reproducible automation and narrowly worded claims:

• CI builds and tests macOS on Apple Silicon and Intel, plus Windows on x64 and ARM64.
• The deterministic v1 release suite runs on every release candidate through npm run v1:test; CI output is the source of truth for its current count.
• TypeScript and Swift passed all 31 shared behavior-contract cases with byte-identical output.
• Windows CI commits a selected Devanagari candidate through a real TSF thread manager, document manager, context, edit session, and in-memory text store.
• Windows x64 CI installs silently, verifies 64-bit and 32-bit COM/TSF registration plus local service startup, uninstalls, and verifies cleanup.
• The macOS package simulation verifies quarantine detection, the preferred Finder approval path, universal architecture, and package integrity.
• The final bounded adversarial review recorded zero open P0 issues. It does not replace the limitations below or claim universal host-app testing.

Explore the evidence:

• Current CI workflow
• Windows release build and physical validation matrix
• macOS unsigned-install walkthrough
• Traditional / Preeti corpus result
• Known limitations

Experimental neural research

The repository contains an active local Core ML transliteration research track. It is not the v1.0 product, is not production-ready, is off by default, and is absent from the published v1.0 packages. The deterministic engine remains the shipping path.

Current research evaluates candidate architectures and an evidence-bound promotion pipeline. No model will be described as Neural Engine-backed merely because Core ML was asked to make the Neural Engine available; actual placement and final packaged performance still require proof.

See the latest neural production-readiness checkpoint for measured results, resolved findings, and remaining blockers.

Known limitations

Honest limits are part of the product contract:

• The macOS package is not Apple-notarized, and the Windows package is unsigned.
• Physical Windows behavior in Notepad, browsers, and Microsoft Word has not been claimed as visually verified; the native commit path and candidate state machine use automated CI proxies.
• The companion and installer target Windows 11 x64. The installer includes a separate x86 TSF DLL so the keyboard can load in 32-bit applications; a Windows ARM64 installer is not yet shipped.
• Traditional typing is Beta and lacks a verified physical-layout corpus and experienced-typist sign-off.
• The Preeti converter has extensive locked-fixture regression coverage but no consented real-document validation set.
• Proofread is conservative active-token assistance, not full grammar correction.
• v1.0 has no automatic update service.

The complete release-honesty record is in KNOWN_LIMITATIONS.md.

Uninstall

macOS

Switch to ABC first. Open the original extracted installer folder, right-click Lekh Keyboard Uninstaller.app, choose Open, and confirm removal. The uninstaller removes the input method and Lekh-owned local data, including learned words, packs, backups, caches, and logs.

Windows

Open Settings → Apps → Installed apps, find Lekh Keyboard Companion, open its … menu, and choose Uninstall. Approve the User Account Control prompt. The uninstaller stops the companion and broker, removes startup registration, unregisters the text service, and removes installed files.

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Build from source

Everything below is for contributors. End users should use the release installers above.

Prerequisites

• Node.js 24
• npm 11
• macOS: Xcode Command Line Tools and a compatible macOS SDK
• Windows: Visual Studio Build Tools, CMake, and the Windows SDK

git clone https://github.com/dantwoashim/Lekh_Assistant.git
cd Lekh_Assistant
npm ci
npm run v1:check

Primary v1 command surface

These eight commands are the documented top-level v1 entry points. Lower-level maintenance and research scripts remain in package.json for maintainers.

Command	Purpose	Host
npm run v1:dev	Start the local development surface	macOS / Windows
npm run v1:build	Build the web and companion UI	macOS / Windows
npm run v1:test	Run the deterministic v1 test suite	macOS / Windows
npm run v1:check	Run format, types, tests, build, IPC, and commit-policy checks	macOS / Windows
npm run v1:build:macos	Compile the native macOS input method with neural typing off	macOS
npm run v1:build:windows	Compile and test both 64-bit and 32-bit Windows TSF services	Windows
npm run v1:package:macos	Build and verify the unsigned universal installer ZIP	macOS
npm run v1:package:windows	Build the unsigned x64 Windows installer	Windows

Repository map

src/                         Deterministic engine and focused UI
native/macos-imk/skeleton/   macOS InputMethodKit implementation
native/windows-tsf/skeleton/ Windows Text Services Framework implementation
native/daemon/               Local deterministic daemon
native/shared/               IPC and local-storage contracts
scripts/                     Build, packaging, and verification automation
data/                        Bundled deterministic language data
docs/                        Architecture, safety, research, and release records

Architecture truth matters:

• The macOS keyboard is the InputMethodKit input method.
• The Windows keyboard is the TSF text service.
• The companion configures and supports the keyboard; it is not the keyboard.
• The Electron/browser surface is a development and demonstration surface; it is not the system keyboard.
• Preeti-to-Unicode conversion is a side utility, not the main typing path.

Contribute

Before opening a change, read:

• Contributing guide
• Security policy
• Third-party notices

License

Lekh Assistant is available under the MIT License.

Your words. Your device. Your choice.