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cua-sandbox 0.3.3 runs Minecraft in Windows sandbox for computer use agents
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A guide demonstrates how to boot a Windows sandbox running Minecraft Java Edition and drive it with an agent through the cua-driver MCP server, exercising nearly every capability a Windows sandbox can offer.
Running Minecraft in a sandbox validates that computer use agents can handle applications requiring internet access, a Java runtime, working OpenGL, and GUI interaction driven only by clicks. The setup exposes real constraints, CPU model requirements, software OpenGL workarounds, and network isolation, that anyone building agent-driven Windows environments will hit.
Written by elseif from the cluster below · every claim links back to a sourceThe three things worth knowing
cua-sandbox 0.3.3 or newer is required, as earlier versions lack Image.expose(), sb.exposed_ports, and the os_type parameter needed for this configuration.
The default QEMU CPU model is insufficient for Mesa's software OpenGL driver; -cpu host is required, which demands KVM on Linux x86_64 or HVF on Intel Macs.
A second unrestricted network interface must be added because the default NIC uses restrict=on, which blocks internet access that Minecraft needs.
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What the cluster adds up to.
The guide treats Minecraft as a stress test for the Windows sandbox stack. The game needs internet for resource downloads, a Java runtime, OpenGL 3.2 or later, and a GUI that only responds to pointer clicks, covering the capabilities any real desktop application would demand. Getting all of these working inside a sandbox reveals where the defaults break down and what explicit configuration is required. Three specific version gates matter. cua-sandbox 0.3.1 added Image.expose() for the local QEMU runtime. Version 0.3.2 introduced sb.exposed_ports, which the guide reads to find the forwarded port. Version 0.3.3 brought Image.from_registry() with an os_type parameter and a pull-secret fix that Fleet needs to boot an image from an external registry. Anything before 0.3.3 cannot run this configuration. The CPU constraint is sharp. The default qemu64 model causes Minecraft to die silently while loading resources, with no Java exception or crash log. Passing -cpu host fixes this, but QEMU only accepts that flag under KVM or HVF acceleration. An x86_64 guest on Apple Silicon runs under TCG emulation, which rejects -cpu host outright; the Fleet path works there instead, with one extra en
Written by elseif from the cluster below · checked for specifics the sources never containedTHE CLUSTER