> Coherent threads, encrypted.
A retro-pixel Matrix chat client. Encrypted messaging, voice/video calls, and spaces — built with Flutter and running on desktop, mobile, and web.
Version 1.12.0 · GPL-3.0 · Open source
// Features
A complete Matrix client experience — rich messaging, real end-to-end encryption, and organized spaces, all wrapped in a pixel-perfect retro shell.
// Platforms
One codebase, six targets. Kohera runs natively on every major platform.
// Adaptive
The shell reshapes itself to the viewport — from a single column on your phone to a full three-pane workspace on desktop.
| Viewport width | Layout |
|---|---|
| < 720 px | Space rail + room list; chat pushes full-screen |
| 720 – 1100 px | Space rail + room list + content pane (2-column) |
| ≥ 1100 px | Space rail + resizable room list + chat pane (3-column) |
// Install
Grab a release build, run the containerized web app, or build from source.
# Pull the latest web image from GHCR docker pull ghcr.io/quantumheart/kohera:latest # Run it locally on port 8080 docker run -p 8080:80 ghcr.io/quantumheart/kohera:latest # Then open http://localhost:8080
# Requires Flutter 3.16+ (stable) and Dart 3.1+ git clone https://github.com/Quantumheart/Kohera.git cd Kohera flutter pub get # Run on a device flutter run -d linux # Linux desktop flutter run -d chrome # Web # Release builds flutter build linux --release flutter build windows --release
# Tagged releases publish GitHub Release artifacts: # - Linux tar.gz # - Windows Inno Setup installer # - Web Docker image to ghcr.io # Browse and download from: https://github.com/Quantumheart/Kohera/releases
// Privacy
The developer of Kohera operates no servers that store your messages, contacts, or account data. Your data lives on the Matrix homeserver you choose. Conversations are protected with end-to-end encryption using the Olm and Megolm protocols. Kohera contains no advertising, analytics, tracking, or telemetry SDKs.