---
title: "Week of April 3, 2026"
description: "The microsandbox rewrite around an embeddable SDK, smoltcp networking, and a composable filesystem."
icon: "bolt"
---

<Tip>
  **Released this week:** [v0.3.3](https://github.com/superradcompany/microsandbox/releases/tag/v0.3.3) through [v0.3.10](https://github.com/superradcompany/microsandbox/releases/tag/v0.3.10)
</Tip>

## New features

**Microsandbox rewrite**

Rewritten around an embeddable SDK, smoltcp-based networking, and a composable filesystem:

- First-class Rust SDK that the CLI is built on.
- User-space network stack (smoltcp) with an in-sandbox DNS resolver and TLS proxy.
- Composable filesystem layering OCI images, host volumes, and writable overlays through one VFS.
- Redesigned policy and config model shared across CLI, SDK, and `Sandboxfile`.

Breaking change.

**Other features**

- **Per-command exec flags for `msb run`.** Pass `--env`, `--workdir`, `--tty`, `--timeout`, etc. directly without a `Sandboxfile`.

## Bug fixes

- VM logs split into `guest.log` and `host.log` instead of interleaving.
- Reopening inodes via `/.vol` on macOS no longer fails under `O_RESOLVE_BENEATH`.
- Overlay `readdir` resolves real inode numbers instead of surfacing `0`.
- `ExecTimeout` is returned consistently when an exec call hits its timeout.
- Sandbox creation validates `workdir` up front and defaults `cwd` to `/` when unset.
- `msb self update` resolves the latest version before downloading the bundle.
