Show HN: Drop – a rootless Linux sandbox with gVisor support

Drop is a lightweight, rootless Linux sandbox designed to isolate programs and coding agents without changing the host distribution or workflow. It creates disposable environments with their own home directories so harmful actions - like a hallucinated rm -rf ~ or prompt injection targeting ~/.ssh - cannot touch the real user data. Typical use cases include safely running untrusted packages from PyPI/npm and running LLM-based agents that request overly broad permissions; network interactions with localhost can be restricted and local services hidden. Environments are easy to create and share because Drop uses a high-level TOML config and a shared base config, so you configure isolation once and spawn new sandboxes quickly.

Under the hood Drop runs entirely rootless inside a Linux user namespace, providing separate process, mount, network, IPC and cgroup namespaces while dropping user-namespace capabilities before executing sandboxed programs, preventing privileged operations like bind mounts. It uses the host distribution (no Docker/Podman image setup) so existing user-installed programs are available inside the sandbox. As an extra isolation layer, Drop optionally runs programs on the gVisor user-space kernel to block direct access to the host kernel and reduce kernel-exploit risk. The design balances convenience, configurability and strong OS-level containment.