GuestKit

What's new

Full history: CHANGELOG.md.

Why GuestKit

Every hypervisor exit fails the same way: you discover the disk was broken at 2am, in the cutover window, after power-on. GuestKit reads the disk while the guest is off — qcow2, VMDK, VHDX, VHD, VDI or raw — through its own pure-Rust engine (NBD or loop mount). There is no appliance daemon and no "power it on and see".

Fixes are never implicit. Repairs go through a plan you can read, applied with backups and rollback, and the same score drives the CI gate, the signed Cutover Passport, and assured QEMU launch.

[Capabilities at a glance: Assure, Repair, Certify, Surfaces]

The full comparison has more rows, including fleet drift, the Carbon TUI with the in-guest agent, and guestkit qga as a drop-in for virsh qemu-agent-command.

GuestKit vs libguestfs + virt-v2v

[GuestKit vs libguestfs + virt-v2v: not just convert it, prove it will boot]

GuestKit sits next to conversion tools rather than replacing all of them: h2kvm converts and deploys, and calls GuestKit for the offline fixes.

See it live

How it fits together

[Read the disk offline; decide before power-on]

  disk.qcow2 / .vmdk / .vhdx / .vhd / .vdi / .raw                    │                    ▼         ┌──────────────────────┐         │  Pure-Rust engine    │──►  doctor 0–100 + blockers         │  NBD / loop mount    │──►  migrate-plan YAML         └──────────────────────┘──►  Passport · repair · CI gate                    │                 guestkit-qemu (assured launch)      CLI · TUI · QEMU · Python · Web · Agent · GitHub Action

Export with Transiva (Apache-2.0) → convert & deploy with h2kvm (Zyvor Production License) → assure with GuestKit (Apache-2.0) → operate on Zorvia or Zeus OS. Run and manage VMs with FluxVM. Who does what · h2kvm integration

Architecture in depth: docs/architecture/overview.md.

Quickstart

# v1.2.6 GitHub Release — crates.io `guestkit` is still 0.3.2curl -fsSL -O https://github.com/zyvorai/zyvor-guestkit/releases/download/v1.2.6/guestkit-1.2.6-linux-amd64.tar.gz
guestkit doctor vm.qcow2 --target proxmox --explainguestkit migrate-plan vm.vmdk --target kvm --export plan.yamlguestkit passport emit vm.qcow2 --target kvm -o passport.jsonguestctl tui vm.qcow2           # Assurance · preview · exportguestkit-qemu plan vm.qcow2 --json   # assurance → QEMU definition

CI gate — same score, no CLI install step:

- uses: zyvorai/guestkit@v1  with:    disk: vm.qcow2    target: kvm    fail-below: '80'

Targets: kvm · proxmox · qemu · kubevirt · aws · azure · gcp · hyperv. Host needs: Linux with qemu-img, losetup, and qemu-nbd (mount/repair may need root).

Python (v1.1.0+), on PyPI: pip install zyvor-guestkit, then guestkit.run_doctor("vm.qcow2", target="kvm", explain=True). The full quick start, shrink and Python examples: docs/quick-start.md.

MCP server — guestkit mcp-serve <image> [--target kvm] is a stdio MCP server exposing six read-only evidence tools for one disk image. Build with cargo build --release --features mcp. Registry name io.github.zyvorai/guestkit; OCI image ghcr.io/zyvorai/guestkit-mcp. Opening a disk needs loop/NBD, so the container must run as root with --privileged (or SYS_ADMIN plus devices) despite its nonroot default user. See docs/guides/MCP.md and DOCKER.md.

Documentation

The complete map, with the changelog and roadmap, is in docs/documentation-map.md.

Go deeper

• Gallery: console screenshots and demo videos — docs/gallery.md.
• Who does what: the suite split and the libvirt/virsh map — docs/who-does-what.md.
• h2kvm integration: docs/h2kvm-at-a-glance.md.
• What you can do: assure, plan, certify, repair, launch — docs/capabilities.md.
• Free web stack (GHCR): docs/web-stack-ghcr.md.
• Open source vs Enterprise: docs/oss-vs-enterprise.md.
• Platform layout: docs/platform-layout.md.
• Repository: docs/repository-layout.md.
• Prerequisites and build: docs/prerequisites-and-build.md; docs/ and this README are authoritative.

Open source, Enterprise

Open source — free under Apache-2.0. This repo · personal, lab, and commercial production. Full offline doctor, migrate-plan, repair, fleet, policy · CLI · TUI · Python · self-hosted web/workers.

Enterprise — buy for programs. Same engine — not a locked doctor. Command Center · Portfolio · Assurance · Migration Factory · Passport Authority · OIDC / RBAC / audit · SLA · air-gap · hypervisor exit workshops.

Open source vs Enterprise · Full feature matrix · 30-day Enterprise trial · Pricing

Trial expired or want a guided evaluation? Book a demo or start a 30-day PoC — no email needed. [email protected] remains as a fallback.

Maturity

GuestKit is at v1.2.6 (GitHub Release; PyPI zyvor-guestkit; crates.io guestkit is still 0.3.2). The architecture overview states the engine's scope plainly:

Part of the Zyvor stack

→ zyvor.dev

Support

Free under Apache-2.0. If it helps you, you can donate any amount you like: https://payments.cashfree.com/forms/zyvor-donate. A donation is voluntary and supports development and maintenance. It is not a purchase: it buys no support, SLA, features, priority or license, and it is not tax-deductible (Zyvor AI Labs Private Limited is a company, not a charity). Zyvor Enterprise (supported releases, SLAs, a named contact and enterprise features) is separate: [email protected].

License

GuestKit is free and open source under the Apache License, Version 2.0. You may use, modify, and run it for personal, lab, and commercial production use at no charge, subject to Apache-2.0 (preserve notices / NOTICE where required). See NOTICE and docs/legal/ where applicable. That does not change.

Zyvor Enterprise adds what production teams ask for: supported releases, deployment and upgrade guidance, priority incident triage, a named technical contact and 24x7 critical intake. Production support, SLAs, and Zyvor Enterprise products are licensed separately. Plans and terms: docs/SUBSCRIPTION-MODEL.md · Pricing · [email protected].

Report vulnerabilities privately per SECURITY.md. More at zyvor.dev/guestkit · docs · blog.