Lume is a VM runtime built by Cua (YC X25) that solves a specific problem for developers on Apple Silicon: running AI coding agents in fully isolated macOS or Linux virtual machines with near-native performance. When you give Claude Code or Codex CLI permission to execute shell commands and modify files, there is always a risk that an agent makes a destructive mistake. Lume provides the safety net — each agent session runs inside its own VM with an independent filesystem, network stack, and system state that can be snapshotted and rolled back instantly.
Built on Apple's native Virtualization.Framework, Lume avoids the overhead of traditional hypervisors and achieves performance that is nearly indistinguishable from running natively. This is a key differentiator from Docker-based sandboxing: Docker cannot run macOS containers, and Linux containers share the host kernel, offering weaker isolation. Lume creates true virtual machines with their own kernel, making it suitable for testing macOS-specific code paths, running CI/CD builds for Apple platforms, and creating disposable development environments. The CLI supports creating, starting, stopping, and snapshotting VMs with simple commands.
The broader Cua platform extends Lume into computer-use agent infrastructure — AI agents that can operate macOS and Linux desktops autonomously for testing, automation, and research. With over 12,900 GitHub stars on the monorepo, MIT licensing, and active development, Lume fills a unique gap in the developer tools landscape. The Show HN launch in January 2026 reached 521 points on Hacker News, confirming strong developer interest in Apple Silicon virtualization for agent sandboxing and CI/CD use cases.