sandboxes

sandboxes gives every user a private, throwaway environment where code runs and shows up at a shareable preview URL. It's built for the AI app-builder pattern: a user describes an app, an agent writes it, and it goes live at a link. One Go binary orchestrates Docker containers with automatic preview URLs and TLS, no Kubernetes involved. MIT licensed.

The density trick is stop-on-idle and wake-on-request, so a single box can hold a lot of sandboxes without keeping them all warm. OpenCode and Claude Code agents come preinstalled, and there's an HTTP API to create, run, and destroy environments. You'll need a Linux VPS with Docker. The install is one command, but you own host security, scaling, and TLS from there.

This is the open alternative to E2B and Daytona, the paid sandbox-as-infrastructure services that AI coding products run on. It also overlaps the backend of app-builders like Lovable, Bolt, and Replit. Solo and small teams prototyping agent infrastructure: self-host it. Teams shipping this to real users: read the security notes first, then decide.

The catch: it's days-old beta, and the isolation is containers, not VMs, so the README itself warns it is not safe for running untrusted strangers' code without gVisor, Kata, or Firecracker. API auth is also off by default. Fine for your own agents, risky for a public service as it ships.