nono

nono is an open-source, kernel-enforced capability shell designed to safely run AI agents and other untrusted processes under strict operating system controls. The project addresses a growing security concern: modern coding agents typically execute with full user permissions, which means they can potentially read sensitive files, modify system configurations, or exfiltrate credentials if compromised. nono solves this by applying default-deny sandboxing at the kernel level using technologies such as Landlock on Linux and Seatbelt on macOS, making unauthorized actions structurally impossible rather than merely discouraged. Unlike container-based approaches, the tool is intentionally lightweight and can wrap any command-line process without requiring images, VMs, or complex infrastructure. The system emphasizes capability-based security, where processes are granted only the exact filesystem paths and network access they need, and nothing more.