Komai (こまい)

A fine Matrix chat app you can get to love

🦁 Komai is a desktop-first Matrix chat application built with Rust, C++ and QML. It traces its origins to a usability-focused fork of nheko, rebuilt around the Rust matrix-sdk runtime with a growing Rust core.

🤖 Komai is built with AI. Professional engineers + AI coding agents (Claude Code, Codex) working together to build a complex native application in a language stack that isn't the team's primary expertise. We think AI in capable hands can deliver above-average results.

Komai was created by the etke.cc team, but contributions by anyone are welcome! It's fully Free Software (GPL-3.0-or-later), with no CLA and no contributor gatekeeping.

If you're curious about the origin of this project and its name, see the 🦁 Identity documentation page.

🎯 Design Philosophy

• 🖥️ Desktop-first UX — optimized for large screens
• 👓 Readable and easy to use — comfortable text, strong contrast, and Fitts's-law hit targets
• 🎨 Yours to shape — themeable, customizable, and config-management friendly YAML
• ⚡ Responsive by design — native performance is a design constraint
• 🎓 Educate, don't over-abstract away — Arch Linux style: expose Matrix's real concepts
• 🧠 For both grandma and power users — neither dumbed down nor buried in complexity

🌟 Features

• 💬 Matrix messaging with end-to-end encryption support, on the Rust matrix-sdk runtime
• 📎 Attachments (file, image, audio) with a built-in media viewer and in-app video playback
• 🎙️ Voice transcription -- long-press Space to dictate speech into the composer (OpenAI-API-compatible)
• ✍️ Spell checking -- offline, multi-language, with a bundled English dictionary; picks up your system's Hunspell dictionaries
• 📞 Calls -- legacy 1:1 voice only; video/screen-share buggy. Disabled by default; no Element Call yet
• 😀 Emoji messages with custom emojis and localized CLDR keyword search (:whiskey finds 🥃)
• 💬 Replies, Discord-style threads, and message forwarding
• 👥 Multi-account support via dedicated application profiles
• 🎨 10+ built-in themes tuned for WCAG AA contrast, plus user themes
• 🌐 30+ languages, with AI-assisted gap filling
• 🔧 Lots of configuration settings, grouped into tabs and searchable
• 🧭 Polished Room Directory with built-in matrixrooms.info (MRS) search and filters
• 📋 Good support for hundreds of rooms and spaces
• 📑 Browser-style room tabs with pinning -- still rare among Matrix clients
• ⌨️ Keyboard-driven main chat workflow, with human- and Vim-style shortcuts
• 🔀 Selection mode for bulk actions (forwarding, moderation)
• ⚡ Quick, lightweight native app (Rust, C++, QML) -- no Electron
• 🤖 Automation via MCP, CLI commands, and the D-Bus API
• 🕊️ Fully Free Software (GPL-3.0-or-later), no CLA, no gatekeeping

Curious where Komai came from and what changed along the way? See 📄 Differences from nheko.

📸 Screenshots

Welcome	Sign in	Register
Main view	Settings	Dark Matrix theme

More screenshots are inlined on individual feature pages — see the 👤 User Guide.

📥 Installation

🐧 Linux (x86_64): Komai ships as AppImage, Flatpak, and Snap packages on the GitHub Releases page, plus a komai package on the Arch Linux AUR.

🪟 Windows (x64): a portable ZIP for Windows 10 (22H2+) and later is attached to each GitHub release. The build excludes VOIP (no voice or video calls) and isn't code-signed, so the first launch shows a SmartScreen warning that needs More info -> Run anyway.

🍏 macOS: there are no official builds. macOS hasn't been tested by the maintainers; tentative pointers for building from source are in 📄 Native build on macOS.

See 📄 Installation for download links and install commands. To build Komai yourself, see 📄 Native build.

📚 Documentation

See 📄 Documentation for the full list of guides, including settings, theming, translations, and packaging.

🤝 Contributing

• 👨‍💻 Development — building, testing, and code contributions
• 🌐 Translations — improving translations or fixing awkward wording

🆘 Support

• 💬 Matrix room: #komai:etke.cc
• 🐛 GitHub issues: etkecc/komai/issues

🙏 Acknowledgements

Komai started as a fork of nheko by the Nheko-Reborn team. We're grateful for the original application and the Qt/QML groundwork that made Komai possible.

Komai's Matrix protocol and end-to-end encryption core is built on the matrix-rust-sdk by the matrix.org team — a polished, well-documented Rust runtime that made the move off mtxclient + libolm tractable for us, and that positions Komai for everything that comes next in the Matrix ecosystem.

• Boring Avatars — default avatar generation algorithms (Beam, Marble, Bauhaus styles), ported from TypeScript to C++
• Fluent UI System Icons — primary icon set (MIT)
• Font Awesome Free — supplementary icons and brand logos (CC BY 4.0)
• Tinted Theming (Base16)