LeanType Voice Plugin

August 27, 2026 · View on GitHub

Offline voice input plugin for LeanType Keyboard.

Overview

This plugin provides fast, on-device offline speech-to-text capabilities using whisper.cpp for the LeanType Keyboard via an IPC AIDL contract (IVoiceEngine).

Architecture

  • Engine: Whisper.cpp with ARM64 NEON optimizations & JNI bridge
  • AIDL Interface: com.leanbitlab.leantype.voice.IVoiceEngine
  • Service Action: com.leanbitlab.leantype.voice.offline.ENGINE

✨ Features

  • 🎙️ 100% On-Device Speech Recognition: Fast, private speech-to-text powered by whisper.cpp with ARM NEON acceleration.
  • 🌍 99+ Languages Supported: Multi-lingual transcription with auto-detection and language-specific Whisper models.
  • 🛡️ Complete Privacy & Zero Internet: Speech audio never leaves your device. Operates 100% offline.
  • ⚡ Real-Time Audio Visualizer: Live waveform visualization, silence threshold sliders, and background keep-alive.
  • 🔄 Universal Compatibility: Compatible across all 4 LeanType flavors (Standard Full, Standard, Offline, and Offline Lite).

📋 System Requirements

  • Operating System: Android 5.0 (API 21) or higher
  • Supported CPU Architectures: arm64-v8a, armeabi-v7a, x86_64
  • Host Keyboard: LeanType v4.1.0+ (All flavors)
  • Permissions: Microphone permission (RECORD_AUDIO)

📥 Installation & Setup Guide

1. Install the Voice Plugin APK

  1. Download the latest release APK (voice_plugin-arm64-v8a.apk, voice_plugin-armeabi-v7a.apk, or universal) from GitHub Releases.
  2. Install the APK on your Android device (Unlike dynamic plugin libraries, the Voice Plugin runs as an IPC AIDL service and is installed as an app).
  3. Grant Microphone permission when prompted (or in Android Settings → Apps → LeanType Voice Plugin → Permissions).

2. Download Whisper Models in LeanType

  1. Open LeanType keyboard settings.
  2. Navigate to Settings → Voice typing (or Settings → Plugins → Voice).
  3. Tap Whisper Speech Models:
    • Online Flavors (Standard / Standard Full): Download models directly inside the app with 1 tap.
    • Offline Flavors (Offline / Offline Lite): Download .bin models in your browser and use Import Model to select them from device storage.
ModelSizeSpeedRAM UsageBest For
ggml-tiny.bin~39 MB⚡ Ultra-Fast~150 MBLow-end devices & quick voice typing
ggml-base.bin (Recommended)~74 MB⚡ Fast~250 MBBest balance of accuracy & speed
ggml-small.bin~244 MB🟡 Moderate~600 MBHigh accuracy on modern devices

4. Start Voice Typing

  1. Bring up LeanType keyboard in any text field.
  2. Tap the Microphone icon on the keyboard toolbar.
  3. Speak clearly — text will stream directly into the active input field!

🏗️ Building From Source

./gradlew assembleDebug

License

Licensed under the GNU General Public License v3.0.

💖 Support the Development

If you find this project helpful, consider supporting the continuous development of the LeanType ecosystem:

GitHub Sponsors Open Collective