terranix is a Nix-based infrastructure-as-code tool that generates Terraform or OpenTofu JSON configuration. It combines Terraform providers with the lazy, functional configuration style of NixOS as an alternative to HCL. Users write infrastructure definitions using Nix expressions, and terranix outputs JSON that can be applied with Terraform or OpenTofu using the same providers. It supports module composition, code reuse, and documentation generation through its CLI. Documentation is available at terranix.org alongside manpages for terranix, terranix-modules, terranix-doc-json, and terranix-doc-man.