mcqemu

An MCP server that lets LLM agents manage QEMU virtual machines: launch and stop VMs, inspect them over QMP, manage disk images with qemu-img, take live snapshots, and run commands inside guests through qemu-guest-agent.

Requirements

• Linux with QEMU installed (qemu-system-* and qemu-img on PATH)
• /dev/kvm access for hardware acceleration (optional — TCG emulation works without it, just slower)
• Python 3.11+ managed with uv

Install

# From this checkout
uv sync

# Add to Claude Code
claude mcp add mcqemu -- uv run --directory /path/to/mcqemu mcqemu

What it can do

VMs are daemonized QEMU processes with QMP control sockets, so they survive MCP server restarts. The registry lives in ~/.local/share/mcqemu/, sockets in $XDG_RUNTIME_DIR/mcqemu/.

Guest tools (guest_*) need qemu-guest-agent installed inside the guest OS; the host-side virtio-serial channel is wired on every launch, so installing the agent in the guest is the only step.

Port forwards accept "2222:22" (explicit, collision-checked up front), "auto:22", or just "22" — auto forms pick a free host port and the launch result reports what was chosen.

Quick start

Disposable sandbox from any base image with qemu-guest-agent inside:

sandbox_vm(base_image="~/vms/ubuntu-agent.qcow2")
# -> overlay created, VM booted, agent waited for, free port forwarded to 22
guest_exec(name="sandbox", command="uname", args=["-a"])
sandbox_destroy(name="sandbox")   # stops VM, deletes overlay; base untouched

Installing an OS from scratch:

image_create(path="~/vms/test.qcow2", size="10G")
launch_vm(name="test", disks=["~/vms/test.qcow2"], iso="~/isos/alpine.iso",
          port_forwards=["auto:22"])
# ... drive the installer with vm_screenshot / vm_type_text / vm_send_keys ...
stop_vm(name="test")
launch_vm(name="test", disks=["~/vms/test.qcow2"])
guest_exec(name="test", command="uname", args=["-a"])

Development

uv run pytest                  # unit tests (QMP and subprocess mocked)
uv run pytest -m integration   # acceptance: every tool group against real QEMU
uv run ruff check .

The acceptance suite boots real VMs. The guest-agent and snapshot journey needs a base image with qemu-guest-agent installed — it looks for ~/vms/ubuntu-agent.qcow2, overridable with MCQEMU_TEST_BASE_IMAGE, and skips cleanly when absent.