Cloudflare Sandbox SDK vs DeltaBox Lite

Cloudflare Sandbox SDK

Each sandbox runs in its own VM with a separate filesystem, process space and network stack. No hosted API. You deploy and secure a Worker before an agent can call anything, and the starter has no auth.

DeltaBox Lite

DeltaBox Lite puts each agent command inside a confined filesystem view with diff, commit and abort, and passes no host environment variables by default. It is version 0.1.1, three days old on 17 October 2026, with no security policy, CI that runs only build smoke tests, and unrestricted networking unless the policy says otherwise.

Cloudflare Sandbox SDK

1. Derive the sandbox ID from the authenticated user, as the docs advise. IDs aren't secrets
2. Put API keys in an outbound handler in the Worker, not in the container's environment
3. Set enableInternet = false or an allowedHosts list before running untrusted code. Internet access is on by default
4. Check that a restored backup has every directory you expect. Backups of 10 MB or more have open bugs
5. Start new projects on 1.0. The 0.x library only gets fixes until 31 December 2026

DeltaBox Lite

1. Skip step 5 of install-prompt.txt. Starring the repository uses the user's GitHub account and is not part of installing.
2. Pass --commit or --abort to deltabox run explicitly. The child's exit status is preserved after that decision.
3. Wrap redirection and pipes in sh -c '...'. An unquoted > is handled by the host shell and writes outside the sandbox.
4. Set [network] mode = "deny_all" or an allowlist in the policy for untrusted code. The default allows every destination.
5. Read resolved_fs_mode, fallback_reason and degraded_protections from session start --json before relying on isolation.