dotfiles

macOS (Apple Silicon) personal environment managed by nix-darwin + home-manager + Determinate Nix.

Layout

• flake.nix — flake entry point (inputs, darwinConfigurations, homeConfigurations, formatter).
• nix-darwin.nix — system-level settings (Determinate Nix, Homebrew casks, system.defaults, ...).
• home-manager.nix — user-level packages, home.file, xdg.configFile.
• homefiles/ — files that are symlinked into $HOME (e.g. .zshrc, .gitconfig).
• configfiles/ — files that are symlinked into $XDG_CONFIG_HOME (~/.config).

Tooling boundaries

Each layer has a narrow responsibility. When adding something new, pick the layer below and avoid overlapping managers.

Layer	Scope	What goes here	Where it is declared
Determinate Nix	Nix daemon / store	The Nix runtime itself, daemon settings, garbage collection	Installed by install.sh; integrated via determinateNix.enable = true; in nix-darwin.nix.
nix-darwin	macOS system settings	system.defaults (Dock, Finder, ...), launchd services, environment.shells, homebrew = { ... } declaration, system.primaryUser	nix-darwin.nix
home-manager	Per-user files and CLI packages	CLI tools (gh, lazygit, jq, ...), fonts, home.file / xdg.configFile symlinks	home-manager.nix + homefiles/ + configfiles/
Homebrew (casks)	macOS GUI apps that aren't in nixpkgs	Apps that need OS integration (input methods, kernel extensions) or aren't packaged for aarch64-darwin (e.g. google-japanese-ime, onyx, claude desktop)	homebrew.casks in nix-darwin.nix
mise	Per-project language runtimes	Go, Rust, and any runtime that benefits from per-directory version switching	configfiles/mise/config.toml

Decision guide

When adding a new tool, ask in order:

1. Is it a GUI app?

   • In nixpkgs (e.g. obsidian, vscode): add to home.packages.
   • Not in nixpkgs, or needs deep OS integration: add to homebrew.casks.

2. Is it a language runtime (rustc, node, python, go, ...)?

   • Use mise. Keeps versions switchable per project and avoids rebuilding the Nix store each time a version is bumped.

3. Is it a CLI tool?

   • Default: add to home.packages in home-manager.nix for reproducible, lock-file pinned installs.
   • Avoid using Homebrew for CLIs — it bypasses the flake lock.

4. Is it a dotfile?

   • Goes under $HOME: put it in homefiles/.
   • Goes under ~/.config (XDG): put it in configfiles/.
   • Both directories are auto-synced via builtins.readDir; no home-manager.nix changes are required for new files.

Why this split?

• Nix/home-manager first maximises reproducibility: flake.lock pins exact versions across machines.
• Homebrew remains because a handful of macOS-only apps (input methods, maintenance utilities) can't practically be packaged via Nix.
• mise handles languages because per-project version pinning is painful in pure Nix, and language toolchains change more often than system tools.

Installation

xcode-select --install

git clone https://github.com/takumism/dotfiles.git ~/.dotfiles
cd ~/.dotfiles

Edit flake.nix if you need a different username / system:

username = "takumism";
system = "aarch64-darwin";

Then run:

./install.sh

install.sh installs Determinate Nix (if missing), Homebrew (if missing), and applies the nix-darwin configuration.

Updating

# Pull the latest input revisions into flake.lock.
nix flake update

# Re-apply the full nix-darwin + home-manager configuration.
sudo darwin-rebuild switch --flake ".#takumism"

# Apply the home-manager layer only (useful for quick iteration).
sudo nix run home-manager -- switch --flake ".#takumism"

# Grabage collection
nix-collect-garbage

Formatting

nix fmt