DeltaBox Lite vs Modal Sandboxes

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.

Modal Sandboxes

GPU sandboxes at the same per-second rates as the rest of Modal. No REST API, and the JavaScript and Go SDKs are beta.

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.

Modal Sandboxes

1. Pass timeout= when you create a sandbox. The default lifetime is 5 minutes
2. Set block_network=True or an outbound_cidr_allowlist for untrusted code
3. Give a sandbox a name so a retried create raises AlreadyExistsError instead of starting a second one
4. Snapshot the filesystem before the 24-hour limit and start a fresh sandbox from it
5. Catch ResourceExhaustedError from Sandbox.create() on SDK 1.6.0 and later, since create now waits until scheduled