Quicksand

Quicksand is an async Python API to launch, control, and snapshot QEMU virtual machines with a particular focus on sandboxing AI agents. Quicksand provides pre-built Linux VMs for Ubuntu and Alpine distros. It works on x86_64 and ARM64 across macOS, Linux, and Windows with no root privileges, no Docker, and no system dependencies. Just pip install quick-sandbox.

Installation

pip install 'quick-sandbox[qemu,alpine]'

Or install the core package and add QEMU/images separately:

pip install quick-sandbox
quicksand install qemu alpine

Usage

Hello, World!

import asyncio
from quicksand import Sandbox

async def main():
    async with Sandbox(image="ubuntu") as sb:
        result = await sb.execute("echo 'Hello from the sandbox!'")
        print(result.stdout)

asyncio.run(main())

Run commands

result = await sb.execute("apt update && apt install -y python3")
print(result.stdout, result.exit_code)

Mount host directories

Share host directories into the VM at boot or on the fly.

# At boot
async with Sandbox(
    image="ubuntu",
    mounts=[Mount("./workspace", "/mnt/workspace")],
) as sb:
    ...

# Or dynamically on a running sandbox
handle = await sb.mount("/tmp/data", "/mnt/data")
await sb.execute("ls /mnt/data")
await sb.unmount(handle)

Configure networking

Sandboxes are network-isolated by default. Opt in to internet access and port forwarding with NetworkMode.FULL.

async with Sandbox(
    image="ubuntu",
    network_mode=NetworkMode.FULL,
    port_forwards=[PortForward(host=8080, guest=80)],
) as sb:
    ...

Save and load

Save the VM's disk state to a directory. Load it later, even on a different machine.

await sb.execute("pip install numpy pandas")
await sb.save("my-env")  # VM keeps running

# Load later
async with Sandbox(image="my-env") as sb:
    await sb.execute("python3 -c 'import numpy; print(numpy.__version__)'")

Checkpoint and revert

Capture the full VM state and roll back if something goes wrong.

await sb.checkpoint("before-experiment")
await sb.execute("apt install -y something-risky")
await sb.revert("before-experiment")  # the VM snaps back to the checkpoint

Control a desktop

Desktop images provide a full Xfce4 graphical environment with a browser. Install one with quicksand install ubuntu-desktop or quicksand install alpine-desktop.

async with Sandbox(image="ubuntu-desktop", enable_display=True) as sb:
    await sb.screenshot("screen.png")
    await sb.type_text("hello world")
    await sb.press_key(Key.RET)
    await sb.mouse_move(500, 300)
    await sb.mouse_click("left")

Configuration

Here are all of the Sandbox configuration options:

Sandbox(
    # Image or save name to boot
    image="ubuntu",
    # Guest RAM (default: "512M")
    memory="2G",
    # Virtual CPU cores (default: 1)
    cpus=4,
    # Host directories shared into the VM at boot
    mounts=[Mount("/host", "/guest")],
    # NONE, MOUNTS_ONLY (default), or FULL internet access
    network_mode=NetworkMode.FULL,
    # Forward host TCP ports into the guest
    port_forwards=[PortForward(host=8080, guest=80)],
    # Expand the guest filesystem on boot
    disk_size="10G",
    # Attach virtual GPU, keyboard, and mouse for screenshot/type_text/mouse control
    enable_display=True,
    # Auto-save VM state on stop
    save="my-save-name",
)

Available images

Image	Type	Wheel size	Install command	What is it
ubuntu	Base	~341 MB	quicksand install ubuntu	Ubuntu 24.04 headless
alpine	Base	~78 MB	quicksand install alpine	Alpine 3.23 headless (faster boot)
ubuntu-desktop	Overlay (ubuntu)	~263 MB	quicksand install ubuntu-desktop	Ubuntu 24.04 + Xfce4 + Firefox
alpine-desktop	Overlay (alpine)	~310 MB	quicksand install alpine-desktop	Alpine 3.23 + Xfce4 + Chromium
quicksand-agent	Overlay (ubuntu)	~304 MB	quicksand install quicksand-agent	Ubuntu + Python 3.12, uv, build-essential, requests, pyyaml, ddgs, markitdown
quicksand-cua	Overlay (quicksand-agent)	~445 MB	quicksand install quicksand-cua	Agent Sandbox + Xvfb, x11vnc, noVNC, Playwright, Chromium

Building from source

git clone https://github.com/microsoft/quicksand.git
cd quicksand
uv sync
uv run uvr build --all-packages

Documentation

Topic	Guide	Under the Hood
Installation	Installing packages	QEMU binaries, kernels, qcow2 disks
Sandbox Lifecycle	Creating and configuring sandboxes	-m, -smp, -accel, machine types
Running Commands	execute(), streaming, exit codes	Kernel boot, agent tokens, hostfwd
File Exchange	Mounts, hot-mounts, getting data in/out	CIFS via guestfwd, 9p via -fsdev
Save and Rollback	Checkpoints, reverts, persistent saves	qcow2 overlays, savevm, blockdev-snapshot-sync
Desktop Control	Screenshots, keyboard, mouse	VNC, GPU, USB tablet, QMP input injection
Network and Isolation	Network modes, port forwarding	SLIRP NAT, restrict=on, guestfwd
Performance	What makes it fast	io_uring, IOThreads, TCG vs KVM

Contributing

Guide	When to use
Creating Images	Build a new base or overlay image package
Extending the Sandbox	Add a method, OS, architecture, or QEMU flag
Testing	Run or write tests
Releasing	Cut a release

Full guides: User Guide | Under the Hood | Contributor Guide