By name: run-untrusted-code description: Run AI-generated or untrusted code safely in a disposable cloud VM instead of on the host, then delete it. Full root Ubuntu with zero blast radius on the user's machine; per-second billing means a throwaway run costs cents. Use whenever you'd execute code you don't fully trust.
Run untrusted code (Box)
Use this right before executing code you generated or fetched when running it locally would be risky: shell scripts, scraped snippets, dependency installs, anything with side effects. Pattern: create → run → delete, so nothing touches the host.
Why Box
- Isolation — a separate VM; the host filesystem and network are never exposed.
- Disposable & cheap —
box deletewhen done; per-second billing, a run costs cents. - Real machine — generated code that needs
pip install, subprocesses, or Docker actually works.
Prefer another tool for: thousands of tiny <500 ms runs (E2B/Modal microVMs).
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')"
trap 'box delete "$box_id" --json' EXIT # never leak a VM
box ssh "$box_id" -- "mkdir -p /run && cat > /run/main.sh" < ./main.sh
box ssh "$box_id" -- "cd /run && timeout 120 bash main.sh"
Always wrap in timeout and delete in a trap/finally.
Limits
EU-only; disk-level snapshots; 100 active VMs soft cap.