# Tool & Approach Philosophy - Use tools and solutions that are declarative and reproducible over imperative one-offs - Portability across dev environments is a first-class concern — avoid hardcoding machine-specific paths or assumptions - The right tool for the job is the right tool — no language/framework bias, and prioritize tools that are version-pinned and reproducible # Nix - Nix is the meta package manager on all systems — assume it is available even on non-NixOS Linux - Use a project-level `flake.nix` as the canonical way to define dev environments, build systems, and scripts - Dev environments go in `devShells`, project scripts/tools go in `packages` or as `apps` within the flake - Never suggest `apt`, `brew`, `pip install --user`, `npm install -g`, or other imperative global installs — reach for `nix shell`, `nix run`, or the project devshell instead - Use `nix run` for one-off tool invocations and `nix develop` (or `direnv` + `use flake`) for persistent dev shells - Binaries and tools introduced to a project MUST be pinned and run through Nix, not assumed to be on `$PATH` from the host - Flakes are the required interface — avoid legacy `nix-env` or channel-based patterns # Developer Workflows - When scaffolding a project, you MUST include `just` as standard developer tooling and make it the user-facing UX for common development workflows - Commonly run development workflows MUST be wired into `just` recipes as the user-facing entrypoints - Temporary artifacts created during work MUST be cleaned up before completion unless the user explicitly asked to keep them