Nix Flake · Nix Dev Template

purr · git-hooks · nix · nixpkgs · nix-flake

Base Nix flake development template — a minimal, reproducible dev shell with Nix formatters and git pre-commit hooks. Built on purr for zero-friction Nix flake scaffolding and git-hooks.nix for automated quality gates. Batteries included: auto-formatting, dead-code removal, and static analysis enforced before every commit.

Part of the develop-templates collection (nix flake init-ready).

Quick Start

nix flake init

nix flake init -t "github:nixcafe/develop-templates#nix" --refresh

Register a short alias:

nix registry add beans "github:nixcafe/develop-templates"
nix flake init -t beans#nix

Tip: With cattery-modules, beans is pre-registered.

Create from Template

gh repo create my-nix-project --template nixcafe/nix --clone

Enter the Dev Shell

direnv allow        # auto-load flake on cd
# or without direnv:
nix develop

What's Inside

Tool	Purpose	More
nixfmt	Canonical Nix formatter	nixfmt
deadnix	Scan & remove dead Nix code	deadnix
statix	Linter for Nix antipatterns	statix

All three run as git pre-commit hooks and are available inside the dev shell (nix develop).

Customizing

Add Nix Packages

Edit develop/shells/default/default.nix and append packages to the list:

{
  inputs,
  pkgs,
  system,
  ...
}:
pkgs.mkShell {
  packages = with pkgs; [
    nixfmt
    deadnix
    statix
    just       # command runner
    alejandra  # alternative formatter
  ];

  shellHook = ''
    ${inputs.self.checks.${system}.git-hooks.shellHook}
  '';
  buildInputs = inputs.self.checks.${system}.git-hooks.enabledPackages;
}

Pre-commit Hooks

Edit develop/checks/git-hooks/default.nix to enable, disable, or configure hooks:

{ inputs, system, ... }:
inputs.git-hooks.lib.${system}.run {
  src = ../../..;

  hooks = {
    nixfmt.enable = true;
    deadnix.enable = true;
    statix.enable = true;
    # Add more hooks from git-hooks.nix:
    # shellcheck.enable = true;
    # actionlint.enable = true;
  };
}

See the full list of available hooks at git-hooks.nix.

statix Configuration

Tune the linter in statix.toml at the repo root:

disabled = ["repeated_keys"]
ignore = ['.direnv']
nix_version = '2.4'

Project Structure

.
├── flake.nix                          # Flake entrypoint
├── statix.toml                        # statix linter config
├── .envrc                             # direnv: `use flake`
├── .gitignore
│
├── develop/
│   ├── checks/
│   │   └── git-hooks/
│   │       └── default.nix            # Pre-commit hooks (nixfmt, deadnix, statix)
│   │
│   └── shells/
│       └── default/
│           └── default.nix            # Dev shell packages + shellHook

Flake Inputs

Input	URL
nixpkgs	https://flakehub.com/f/NixOS/nixpkgs/0.1.*.tar.gz
purr	https://flakehub.com/f/nixcafe/purr/0.1.*.tar.gz
git-hooks	https://flakehub.com/f/cachix/git-hooks.nix/0.1.*.tar.gz

All inputs follow nixpkgs for a single consistent package set.

Quick Reference

nix develop               # Enter dev shell
nix flake check            # Run all checks (includes git-hooks)
nix fmt                    # Format flake.nix with nixfmt
statix check .             # Lint all Nix files
deadnix -f                # Scan and remove dead code