Boot a Windows sandbox, install Minecraft Java Edition, and drive it with an agent through the cua-driver MCP server running inside the sandbox. Minecraft exercises almost everything a Windows sandbox can do: it needs internet access, a Java runtime, working Open GL, and a GUI that only clicks can drive.

Before you start, use cua-sandbox 0.3.3 or newer. A host with hardware virtualisation for the local path—a Linux x86_64 machine with /dev/kvm, or an Intel Mac. The Fleet path runs on Apple Silicon with one extra environment variable. You need a Microsoft account that owns Minecraft Java Edition, and a vision-capable LLM endpoint.

Boot a Windows sandbox with Image.windows(), which resolves to a pinned Windows Server 2022 container Disk. Add .expose(3000) to publish cua-driver's MCP server, a second network interface for internet access (the default is isolated with restrict=on), and -cpu host for the software Open GL driver.

The local runtime picks a free host port at boot, readable via sb.exposed_ports. On Fleet, use tunnel.forward() instead. Give the second NIC its own subnet to avoid IP conflicts.