Unnix is a CLI tool and GitHub action for reproducible development environments. It’s similar to mise, but backed by the Nix ecosystem, without depending on Nix at runtime.
Downloading and evaluating Nixpkgs can take a long time, especially in ephemeral environments like CI pipelines. Unnix avoids that by removing derivations from the picture altogether, and getting the store paths directly from services like Hydra and Devbox.
The README goes deeper into how it works under the hood and its limitations. Also see the Rust example for what the manifest file for unnix looks like.
To try it out with flakes, run nix shell github:figsoda/unnix and follow the usage instructions.