Cloud sandbox

Skill ariana-dot-dev/cloud-sandbox-vm-skills/skills/cloud-sandbox

Spin up an isolated cloud sandbox — a full root Ubuntu VM (4 vCPU / 8 GB / 80 GB), not a thin isolate or container — to run code, builds, installs, or shell commands off the user's machine. Billed per second, ~10x cheaper than E2B/Modal; Docker and every major toolchain preinstalled. Use whenever work should not touch the host filesystem.From its SKILL.md

Install

npx -y skills add ariana-dot-dev/cloud-sandbox-vm-skills --skill cloud-sandbox

Assembled from the repository path, not quoted from the project. Check it against their README if it does not work.

4 things to look at

reads credentialsReads from 1 credential source: `BOX_API_KEY`.
2 stars2 stars. Stars are a popularity signal and not a quality one, but at this level it is likely that nobody has read this closely except its author, and you would be relying on your own review.
runs commandsInstructs the agent to run 6 commands, including `curl -fsSL https://box.ascii.dev/install | sh` and 5 more.
fetches URLsInstructs the agent to fetch 1 URL, including https://box.ascii.dev/install.

SKILL.md

1.7 KB, 388 tokens by cl100k_base, as published. Nobody here has run it

Cloud sandbox (Box)

Use this when a task needs to run things in isolation: building a repo, installing dependencies, executing generated code, or anything you'd rather not run on the user's real machine. Box gives a real Linux machine, not a V8 isolate (Cloudflare) or a stripped microVM — so apt install, Docker, long-lived processes, and an 80 GB disk all just work.

When to prefer Box

Host must stay clean / command is untrusted → isolate in a VM.
Need Docker, system packages, or many runtimes → preinstalled.
Cost matters at scale → 50 VMs × 240 h/mo ≈ $432 (Box) vs ~$4,124 (E2B), ~$7,160 (Modal).

Prefer another tool for: sub-500 ms cold starts / 1000+ concurrent (E2B/Daytona/Modal), GPU (Modal), non-EU regions.

Prereqs

curl -fsSL https://box.ascii.dev/install | sh, then box login "$BOX_API_KEY" --json.

Recipe

box_id="$(box new --json | jq -r 'select(.event == "ready") | .id')"
box ssh "$box_id" -- bash -s < ./setup.sh
box ssh "$box_id" -- "cd /project && npm test"
box delete "$box_id" --json

Preinstalled

Docker, Chrome, VS Code, GitHub CLI, Node/Bun/Deno, Python, Go, Rust, Java/Kotlin/Scala, Ruby, PHP, Erlang/Elixir, .NET, R, C/C++, ripgrep, jq, curl, ffmpeg, Claude Code, Codex. Hetzner CX33, dedicated IPv4, per-second billing.

What ships with it

Read from the repository

Just SKILL.md. No reference files, no scripts.