Working config for fw13 amd

system/nix/default.nix

@@ -0,0 +1,44 @@
+{
+  config,
+  pkgs,
+  inputs,
+  lib,
+  ...
+}: {
+  imports = [
+    ./nh.nix
+    ./nixpkgs.nix
+    ./substituters.nix
+  ];
+
+  # we need git for flakes
+  environment.systemPackages = [pkgs.git];
+
+  nix = let
+    flakeInputs = lib.filterAttrs (_: v: lib.isType "flake" v) inputs;
+  in {
+    package = pkgs.lix;
+
+    # pin the registry to avoid downloading and evaling a new nixpkgs version every time
+    registry = lib.mapAttrs (_: v: {flake = v;}) flakeInputs;
+
+    # set the path for channels compat
+    nixPath = lib.mapAttrsToList (key: _: "${key}=flake:${key}") config.nix.registry;
+
+    settings = {
+      auto-optimise-store = true;
+      builders-use-substitutes = true;
+      experimental-features = ["nix-command" "flakes"];
+      flake-registry = "/etc/nix/registry.json";
+
+      # for direnv GC roots
+      keep-derivations = true;
+      keep-outputs = true;
+
+      trusted-users = ["root" "@wheel"];
+
+      accept-flake-config = false;
+    };
+  };
+  system.stateVersion = "25.05";
+}

system/nix/nh.nix

@@ -0,0 +1,11 @@
+{
+  programs.nh = {
+    enable = true;
+    # weekly cleanup
+    clean = {
+      enable = true;
+      extraArgs = "--keep-since 30d";
+    };
+    flake = "/home/jsw/NixOS";
+  };
+}

system/nix/nixpkgs.nix

@@ -0,0 +1,5 @@
+{self, ...}: {
+  nixpkgs = {
+    config.allowUnfree = true;
+  };
+}

system/nix/substituters.nix

@@ -0,0 +1,28 @@
+{
+  nix.settings = {
+    substituters = [
+      # high priority since it's almost always used
+      "https://cache.nixos.org?priority=10"
+
+      # "https://anyrun.cachix.org"
+      # "https://fufexan.cachix.org"
+      # "https://helix.cachix.org"
+      # "https://hyprland.cachix.org"
+      # "https://nix-community.cachix.org"
+      # "https://nix-gaming.cachix.org"
+      # "https://yazi.cachix.org"
+    ];
+
+    trusted-public-keys = [
+      "cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY="
+
+      # "anyrun.cachix.org-1:pqBobmOjI7nKlsUMV25u9QHa9btJK65/C8vnO3p346s="
+      # "fufexan.cachix.org-1:LwCDjCJNJQf5XD2BV+yamQIMZfcKWR9ISIFy5curUsY="
+      # "helix.cachix.org-1:ejp9KQpR1FBI2onstMQ34yogDm4OgU2ru6lIwPvuCVs="
+      # "hyprland.cachix.org-1:a7pgxzMz7+chwVL3/pzj6jIBMioiJM7ypFP8PwtkuGc="
+      # "nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs="
+      # "nix-gaming.cachix.org-1:nbjlureqMbRAxR1gJ/f3hxemL9svXaZF/Ees8vCUUs4="
+      # "yazi.cachix.org-1:Dcdz63NZKfvUCbDGngQDAZq6kOroIrFoyO064uvLh8k="
+    ];
+  };
+}