NixOS config, home-manager config with Flakes

First version:

nix-config/
├── flake.nix
├── flake.lock
├── hosts/
│   └── laptop.nix
├── modules/
│   ├── system/
│   │   └── common.nix
│   └── home/
│       └── user.nix
├── home/
│   └── laptop-user.nix

• System-level config goes in hosts/ or modules/system/
• User-level config (Home Manager) goes in home/ or modules/home/

Second version with overlays/ and pkgs/:

🔍 Purpose overlays/:

• Used to override, patch, or extend existing packages in nixpkgs
• Also used to define custom packages or versions

📦 Examples:

• Patch Firefox to use a custom profile
• Replace the version of Neovim with one from GitHub
• Add a package that’s not in nixpkgs at all

🔍 Purpose pkgs/:

• Define custom packages or applications that are not in nixpkgs
• Think of this as your local nixpkgs subset

📦 Examples:

• A custom CLI tool you wrote
• A shell script you want to wrap as a package
• An overlay-independent custom build

Third version with `libs:

The lib/ directory is for your custom helper functions and utilities written in Nix. Think of it as your personal toolbox 🧰 for reusable logic that doesn’t fit into a package, overlay, or module

configuration.nix

In the flake-based NixOS config structure, the file configuration.nix is optional — but it's traditionally where all your system settings live when you’re not using flakes. In non-flake NixOS setups, /etc/nixos/configuration.nix is the main entry point that defines your whole system: what packages are installed, what services are running, system users, host settings, etc.

But in a flake-based setup, you often split things up more cleanly:

• You define host-specific config in something like hosts/laptop.nix
• You define common modules in modules/*.nix
• And you reference those in flake.nix under nixosConfigurations

TLDR: If you're using flakes to manage your NixOS configuration, you do not need to use configuration.nix

flake-utils

flake-utils is a helper library that simplifies the boilerplate and adds multi-platform support when you're working with Nix flakes. Without flake-utils, you'd have to manually write out separate outputs (like packages, devShells, nixosConfigurations) per system architecture - x86_64-linux, aarch64-darwin, etc. It gets messy fast.

• Automatically loop over supported systems
• Define shared logic per system (like importing nixpkgs)
• Reduce repetition in your flake.nix

Without flake-utils

outputs = { nixpkgs, ... }: {
  packages.x86_64-linux.default = import nixpkgs { system = "x86_64-linux"; };
  packages.aarch64-linux.default = import nixpkgs { system = "aarch64-linux"; };
  ...
};

With flake-utils

outputs = { self, nixpkgs, flake-utils, ... }:
  flake-utils.lib.eachDefaultSystem (system:
    let pkgs = import nixpkgs { inherit system; };
    in {
      packages.default = pkgs.hello;
    }
  );

config macos system p

  system = {
    stateVersion = 5;

    keyboard = {
      enableKeyMapping = true;
    };

    defaults = {
      dock = {
        autohide = true;
        show-recents = false;
        static-only = true;
      };

      finder = {
        _FXShowPosixPathInTitle = true; # show full path in finder title
        AppleShowAllExtensions = false;
        FXEnableExtensionChangeWarning = false;
        QuitMenuItem = true;
        ShowPathbar = true;
        ShowStatusBar = true;
      };

      trackpad = {
        Clicking = true;
      };

      NSGlobalDomain = {
        "com.apple.swipescrolldirection" = false;
        "com.apple.sound.beep.feedback" = 0;

        AppleInterfaceStyle = "Dark"; # dark mode

        NSAutomaticCapitalizationEnabled = false; # disable auto capitalization
        NSAutomaticDashSubstitutionEnabled = false; # disable auto dash substitution
        NSAutomaticPeriodSubstitutionEnabled = false; # disable auto period substitution
        NSAutomaticQuoteSubstitutionEnabled = false; # disable auto quote substitution
        NSAutomaticSpellingCorrectionEnabled = false; # disable auto spelling correction
        _HIHideMenuBar = true;
      };

      # Customize settings that not supported by nix-darwin directly
      # see the source code of this project to get more undocumented options:
      #    https://github.com/rgcr/m-cli
      #
      # All custom entries can be found by running `defaults read` command.
      # or `defaults read xxx` to read a specific domain.
      CustomUserPreferences = {
        ".GlobalPreferences" = {
          AppleSpacesSwitchOnActivate = true;
        };
        NSGlobalDomain = {
          WebKitDeveloperExtras = true;
        };
        "com.apple.finder" = {
          ShowExternalHardDrivesOnDesktop = false;
          ShowHardDrivesOnDesktop = false;
          ShowMountedServersOnDesktop = true;
          ShowRemovableMediaOnDesktop = true;
          _FXSortFoldersFirst = true;
          FXDefaultSearchScope = "SCcf";
        };
        "com.apple.desktopservices" = {
          DSDontWriteNetworkStores = true;
          DSDontWriteUSBStores = true;
        };
        "com.apple.screensaver" = {
          askForPassword = 1;
          askForPasswordDelay = 0;
        };
        "com.apple.screencapture" = {
          location = "~/Desktop";
          type = "png";
        };
        "com.apple.AdLib" = {
          allowApplePersonalizedAdvertising = false;
        };
        "com.apple.ImageCapture".disableHotPlug = true;
      };

      loginwindow = {
        GuestEnabled = false;
        SHOWFULLNAME = true;
      };
    };
  };