zeroboot-vm-sandbox — Claude Code skill: VM sandboxes for agents
This skill runs agent code inside a real KVM virtual machine through Zeroboot, forking a template in under a millisecond.
npx skills add reason-machines/trending-skills --skill zeroboot-vm-sandbox -a claude-codeWhat zeroboot-vm-sandbox does
The skill tells your agent how to execute untrusted code in an actual VM rather than a container. A Firecracker template boots once and its memory plus CPU state are saved to a snapshot. Every new sandbox then maps that snapshot with mmap(MAP_PRIVATE), and the kernel handles copy-on-write page faults on its own.
You get a Python SDK (zeroboot), a Node package (@zeroboot/sdk) and the POST /v1/exec REST endpoint. The examples cover an agent code-execution loop, running several sandboxes concurrently, and wrapping the call as a tool for an LLM. Memory isolation is hardware-enforced, and each fork carries its own kernel instance.
An API key is required: set ZEROBOOT_API_KEY in the environment instead of hardcoding it. Self-hosting needs a Linux host with /dev/kvm, the Firecracker binary and a Rust 2021 toolchain — without /dev/kvm the build fails, and loading the kvm module is the fix.
What it helps with
- run model-generated code without touching your own machine
- spin up a fresh isolated sandbox per agent run
- execute several code snippets concurrently
- expose a code-execution tool to an agent over REST or an SDK
- keep one task's code away from another task's files and memory
Example prompts for the agent
- run this code in a zeroboot sandbox and show me the output
- create an isolated VM sandbox and execute this Python script
- run ten code snippets in parallel through zeroboot
How to install zeroboot-vm-sandbox
1Skills CLI (Vercel)
npx skills add reason-machines/trending-skills --skill zeroboot-vm-sandbox -a claude-code2Manually: put the files in place
~/.claude/skills/zeroboot-vm-sandbox/SKILL.mdCopy the whole skill folder; for one project use .claude/skills/zeroboot-vm-sandbox/
1Skills CLI (Vercel)
npx skills add reason-machines/trending-skills --skill zeroboot-vm-sandbox -a codex2Manually: put the files in place
.agents/skills/zeroboot-vm-sandbox/SKILL.mdFor all projects use ~/.agents/skills/
1Skills CLI (Vercel)
npx skills add reason-machines/trending-skills --skill zeroboot-vm-sandbox -a cursor2Manually: put the files in place
.cursor/skills/zeroboot-vm-sandbox/SKILL.mdCursor also reads .agents/skills/ and .claude/skills/
1GitHub CLI
gh skill install reason-machines/trending-skills zeroboot-vm-sandbox2Manually: put the files in place
.github/skills/zeroboot-vm-sandbox/SKILL.md1Skills CLI (Vercel)
npx skills add reason-machines/trending-skills --skill zeroboot-vm-sandbox -a gemini-cli2Platform CLI
gemini skills install https://github.com/reason-machines/trending-skills --path skills/zeroboot-vm-sandboxManually: put the files in place
.devin/skills/zeroboot-vm-sandbox/SKILL.mdThe legacy .windsurf/skills/ path still works
Skills CLI (Vercel)
npx skills add reason-machines/trending-skills --skill zeroboot-vm-sandbox -a opencodeClaude.ai
Zip the folder and upload it in Settings → Capabilities → Skills
Step by step, with commands for each platform: How to install skills in Claude Code: five ways
Questions about zeroboot-vm-sandbox
How do I install zeroboot-vm-sandbox in Claude?
Run npx skills add reason-machines/trending-skills --skill zeroboot-vm-sandbox -a claude-code. The skill lands in ~/.claude/skills/zeroboot-vm-sandbox/SKILL.md.
What does zeroboot-vm-sandbox do?
It teaches the agent to run code in a separate KVM VM via Zeroboot. The template is forked with copy-on-write, so a new sandbox appears in a fraction of a millisecond.
What do I need for the skill to work?
A ZEROBOOT_API_KEY environment variable and an installed SDK — pip install zeroboot or npm install @zeroboot/sdk. Self-hosting also needs Linux with /dev/kvm.
