A voice box for your AI
Voice conversations with Claude and OpenAI on your own keys
Prototype. Not for use while driving. Not on Google Play.
An experimental Android app: talk to Claude or OpenAI with your own API key. Chats and keys stay encrypted on your phone, with no server of ours in between.
- Prototype
- Apache-2.0
- Android 10+
- Claude
- OpenAI
The problem
Your key, your phone, your conversation.
Many voice assistants route every conversation through a service of their own. Lautwerk talks to the provider you choose, with your own API key, and keeps keys and chats encrypted on the device.
Features
What it does
Voice conversations with two providers
Claude and OpenAI behind one voice flow: Android's speech recognition, the provider's model and Android's text-to-speech.
Your own keys, encrypted
API keys are stored encrypted with the Android Keystore and never leave the phone except to the provider.
Encrypted history with search
Past conversations stay on the device, encrypted, and can be searched.
Export a chat as text
Any conversation can be exported as plain text.
German and English
The app follows the language of the system and the Azentrius design.
The Android Auto prototype
A minimal car screen built with the Car App Library and tested in the Desktop Head Unit (DHU), Google's emulator for car screens. There is no approved Android Auto category for it, and it is not meant for use while driving.
Security
- Keys and chats are stored encrypted on the device.
- There is no Azentrius server in between: the recognised text goes only to the provider you choose.
- Speech recognition and text-to-speech are those of your Android system.
Install
Installation
Requirements
- Android 10 or newer
- An API key from Anthropic (Claude) or OpenAI
- To build: Android Studio with JDK 17, SDK Platform Android 17 (API 37) and Build Tools 36.0.0
Build from source
- Clone Azentrius/lautwerk and open it in Android Studio.
- Set the Gradle JDK to JDK 17 and install SDK Platform Android 17 (API 37) and Build Tools 36.0.0 if they are missing.
- Build the phone app, the variant
app:debug:
./gradlew :app:assembleDebug
- Install the APK on your phone, open the settings, choose a provider and enter your API key.
The repository explains the modules, the Android Auto prototype and the test reports in its README.
Questions
Can I use it in my car?
No. It is a prototype, tested in the Desktop Head Unit, and not meant for use while driving.
Is it on Google Play?
No.
Where do my API keys go?
They stay encrypted on the device. Requests go only to the provider you choose.
Which providers are supported?
Claude and OpenAI.
How do I install it?
Build it from the source with Android Studio. There are no ready-made APKs.
Further reading
Also by Azentrius
- Stellwerk – A local desk display for Claude Code and Codex sessions and their permission requests, for a wide second screen.
- Azentrius Theme – A Home Assistant theme in ink, paper and gold, set in DM Sans, for light and dark mode.