> ## Documentation Index
> Fetch the complete documentation index at: https://docs.microsandbox.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Week of April 3, 2026

> The microsandbox rewrite around an embeddable SDK, smoltcp networking, and a composable filesystem.

<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.