kraftwerk
Cross-platform desktop manager for remote KVM/QEMU virtual machines. Rust + Tauri + Svelte, speaking libvirt over SSH.
A Rust port of the macOS virtmanager Swift app with
meaningful UX overlap with Red Hat's Python virt-manager — without
GTK, without Python, without X11 forwarding.
Connect → Browse VMs → Console (serial/VNC/SPICE) → Configure → Create
Status
Working daily driver against a real KVM host. 353 unit tests + 75 integration tests against a live hypervisor, all green.
Feature parity snapshot with Python virt-manager:
| Area | Status |
|---|---|
| Connect / list / lifecycle (start/stop/pause/resume/reboot/force-off) | ✅ |
| Live CPU + memory editing | ✅ |
| Serial console (crytter WASM terminal) | ✅ |
| VNC console (noVNC, SSH-tunneled) | ✅ |
| SPICE console (capsaicin, native-Rust, with cursor + absolute mouse) | ✅ |
| Virtual networks (list + create NAT/route/open/isolated/bridge) | ✅ |
| Storage pools + volumes (dir/netfs/logical/iscsi, qcow2/raw/iso) | ✅ |
| VM creation wizard (ISO install / import disk / empty) | ✅ |
| Boot / firmware / machine / features / events editor | ✅ |
| Disks (add/edit/remove + CD-ROM live media change) | ✅ |
| NICs (all source types, live link-state toggle) | ✅ |
| Display / video / sound / input | ✅ |
| TPM / RNG / watchdog / panic / balloon / vsock / IOMMU | ✅ |
| Serial / channels (qemu-ga + vdagent presets) | ✅ |
| Filesystem passthrough (virtiofs + 9p) + shmem | ✅ |
| Controllers (USB / SCSI / virtio-serial) | ✅ |
| USB + PCI passthrough (enumerate host devs + attach/detach) | ✅ |
| CPU model/topology/features, cputune, memtune, NUMA, hugepages, iothreads | ✅ |
| Live metrics with sparklines (CPU / memory / disk IO / network IO) | ✅ |
| SEV / TDX launch security | ❌ deferred |
| Snapshots | ❌ deferred |
| Migration UI | ❌ deferred |
See docs/CONFIG_ROADMAP.md for the full surface inventory with constraints and test expectations.
Running it
Prerequisites: Rust 1.90+, Node 20+, libvirt on both the client machine (for the Rust FFI) and the hypervisor, SSH key auth to the hypervisor.
git clone https://github.com/calibrae/kraftwerk
cd kraftwerk
npm install
npm run tauri dev
Point at your hypervisor via the connection dialog; URI shape is
qemu+ssh://user@host/system. The app remembers connections across
launches.
Releases
Pre-built bundles are produced by CI for Linux (AppImage, deb, rpm) and macOS Apple Silicon (signed + notarized DMG). Grab them from the releases page.
Windows is built best-effort (libvirt-on-Windows is second-class; the bundle is not signed).
Client-side libvirt is required
Kraftwerk links against libvirt via FFI, so the client machine
needs it installed even when the hypervisor is remote. The bundle is
not self-contained.
| Platform | Install |
|---|---|
| macOS (Apple Silicon) | brew install libvirt |
| macOS (Intel, local build) | arch -x86_64 /usr/local/bin/brew install libvirt |
| Debian / Ubuntu (.deb) | sudo apt install libvirt0 (pulled in automatically) |
| Fedora / RHEL (.rpm) | sudo dnf install libvirt-libs (pulled in automatically) |
| Arch (AppImage) | sudo pacman -S libvirt |
On first launch the app will crash with a Library not loaded: libvirt.0.dylib
error if libvirt is missing — install it, then reopen.
Intel Macs — build from source
GitHub retired free Intel macOS CI runners in early 2026, so we no longer ship an x86_64 DMG. Intel Macs can still build locally:
# Install Intel Homebrew alongside Apple Silicon Homebrew.
arch -x86_64 /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
# Install libvirt via the Intel brew (goes to /usr/local).
arch -x86_64 /usr/local/bin/brew install libvirt pkg-config
# Point cargo at the Intel libvirt during the build.
cd kraftwerk
npm install
PKG_CONFIG_PATH=/usr/local/opt/libvirt/lib/pkgconfig \
npm run tauri build -- --target x86_64-apple-darwin
The DMG lands in src-tauri/target/x86_64-apple-darwin/release/bundle/dmg/.
It is not code-signed; you'll need to xattr -dr com.apple.quarantine
the .app on first launch, or sign it with your own Developer ID.
Architecture in one paragraph
Tauri app with a Rust backend and a Svelte frontend. Rust holds the
libvirt connection (the virt crate wraps the C API), plus small
modules per feature that parse + patch + build libvirt XML without
touching unrelated sections. The frontend talks to Rust via Tauri's
invoke bridge and receives pushed events (console bytes, SPICE
frames, stat samples). Consoles: serial streams native libvirt
virStream; VNC spawns an SSH port-forward and proxies to a
WebSocket for @novnc/novnc; SPICE spawns an SSH port-forward and
feeds the socket to capsaicin-client (pure-Rust SPICE), pumping
decoded display events as Tauri messages.
See docs/ARCHITECTURE.md and JOURNEY.md for more.
Contributing
See CONTRIBUTING.md. TL;DR:
- Unit tests are mandatory for new parsers / builders / patchers
- Integration tests (against a real libvirt host) are mandatory for anything touching live VMs
- XML escape every string that came from user input
- Read the inactive XML for config editors, not the live XML
- Prefer in-place XML mutation over parse-and-reserialize
License
Dual-licensed under Apache-2.0 and MIT at your option. See LICENSE-APACHE and LICENSE-MIT.
