Runix is a Rust library for interfacing with the Nix command line. It provides typed structs for Nix commands, with typed flags, and interfaces which match with Nix’s underlying classes. It also makes it possible to have a FFI into Nix from Rust. It should greatly improve the state and stability of calling the Nix CLI in your libraries. This talk will introduce the reasoning behind this library in our work at flox, and what it can do for Nix in general.