eve/docs/sandbox/microsandbox.mdx

Filesystem-first framework for durable backend AI agents that run anywhere.

---
title: "microsandbox"
description: "Create local lightweight VMs from an OCI image or Dockerfile."
---

microsandbox environments use eve's default image, an existing OCI image, or `agent/sandbox/Dockerfile`.

```ts
import { defineSandbox } from "eve/sandbox";
import { MicrosandboxSandbox } from "eve/sandbox/microsandbox";

export const environment = MicrosandboxSandbox.dockerfile({
  setup: { autoInstall: false },
});

export default defineSandbox(() => environment.open({ networkPolicy: "deny-all" }));
```

Supported hosts are macOS on Apple Silicon and Linux with glibc and KVM.

## Environment options

Image, CPU, memory, pull policy, environment variables, VM setup, and `prepare` belong to the reusable environment. `eve build` builds a Dockerfile image when present, prepares a VM, and records its snapshot and image references.

## Live VM options

Pass `networkPolicy` to `open()`. The policy applies to the live VM, not the prepared snapshot. microsandbox accepts domain policies and credential transforms.

Session creation uses the recorded snapshot and image directly. Writable VM state persists through the provider's session snapshot lifecycle.

See the [sandbox overview](/docs/sandbox) for managed workspace, skills, parent inheritance, and custom providers.