diff --git a/.envrc b/.envrc
new file mode 100644
index 0000000..8392d15
--- /dev/null
+++ b/.envrc
@@ -0,0 +1 @@
+use flake
\ No newline at end of file
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
new file mode 100644
index 0000000..0165004
--- /dev/null
+++ b/.github/workflows/test.yml
@@ -0,0 +1,22 @@
+name: Test CI
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+
+jobs:
+  test-flake:
+    name: "Test flake options"
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Check out the repository
+        uses: actions/checkout@v7
+
+      - name: Lix GHA Installer Action
+        uses: samueldr/lix-gha-installer-action@v2026-06-15
+
+      - name: Check up flake configuration
+        run: nix flake check --system x86_64-linux --show-trace
diff --git a/checks/biosboot/configuration.nix b/checks/biosboot/configuration.nix
new file mode 100644
index 0000000..76f5d89
--- /dev/null
+++ b/checks/biosboot/configuration.nix
@@ -0,0 +1,31 @@
+{
+  pkgs,
+  ...
+}:
+{
+  networking.hostName = "snow";
+
+  # Select internationalisation properties.
+  i18n.defaultLocale = "en_US.UTF-8";
+
+  console.useXkbConfig = true;
+
+  users.users."test" = {
+    isNormalUser = true;
+    description = "test user";
+    extraGroups = [
+      "wheel"
+      "networkmanager"
+    ];
+  };
+
+  # Allow unfree packages
+  nixpkgs.config.allowUnfree = true;
+
+  # List packages installed in system profile.
+  environment.systemPackages = with pkgs; [
+    htop
+  ];
+
+  system.stateVersion = "26.05";
+}
diff --git a/checks/biosboot/default.nix b/checks/biosboot/default.nix
new file mode 100644
index 0000000..b023534
--- /dev/null
+++ b/checks/biosboot/default.nix
@@ -0,0 +1,43 @@
+# source: https://discourse.nixos.org/t/nixostest-with-flake-configurations/11542/5
+{
+  inputs,
+  pkgs,
+  ...
+}:
+pkgs.testers.runNixOSTest {
+  name = "Efiboot config test";
+
+  nodes.machine =
+    { ... }:
+    {
+      imports = with inputs.self; [
+        nixosModules.biosboot
+        nixosModules.gnome
+        nixosModules.kernel
+        nixosModules.metadata
+        nixosModules.networking
+        nixosModules.packagemanagers
+        nixosModules.pipewire
+        nixosModules.printing
+        nixosModules.snowflakeos
+        ./configuration.nix
+      ];
+    };
+
+  node = {
+    # since we are using an overlay, we must make pkgs writable
+    pkgsReadOnly = false;
+
+    specialArgs = { inherit inputs; };
+  };
+
+  # disable only when working on testScript
+  skipTypeCheck = true;
+
+  testScript = ''
+    machine.start()
+    machine.wait_for_unit("multi-user.target")
+    machine.succeed("uname -a")
+    machine.succeed("echo Modules succesfully tested")
+  '';
+}
diff --git a/checks/efiboot/configuration.nix b/checks/efiboot/configuration.nix
new file mode 100644
index 0000000..76f5d89
--- /dev/null
+++ b/checks/efiboot/configuration.nix
@@ -0,0 +1,31 @@
+{
+  pkgs,
+  ...
+}:
+{
+  networking.hostName = "snow";
+
+  # Select internationalisation properties.
+  i18n.defaultLocale = "en_US.UTF-8";
+
+  console.useXkbConfig = true;
+
+  users.users."test" = {
+    isNormalUser = true;
+    description = "test user";
+    extraGroups = [
+      "wheel"
+      "networkmanager"
+    ];
+  };
+
+  # Allow unfree packages
+  nixpkgs.config.allowUnfree = true;
+
+  # List packages installed in system profile.
+  environment.systemPackages = with pkgs; [
+    htop
+  ];
+
+  system.stateVersion = "26.05";
+}
diff --git a/checks/efiboot/default.nix b/checks/efiboot/default.nix
new file mode 100644
index 0000000..3016007
--- /dev/null
+++ b/checks/efiboot/default.nix
@@ -0,0 +1,43 @@
+# source: https://discourse.nixos.org/t/nixostest-with-flake-configurations/11542/5
+{
+  inputs,
+  pkgs,
+  ...
+}:
+pkgs.testers.runNixOSTest {
+  name = "Efiboot config test";
+
+  nodes.machine =
+    { ... }:
+    {
+      imports = with inputs.self; [
+        nixosModules.efiboot
+        nixosModules.gnome
+        nixosModules.kernel
+        nixosModules.metadata
+        nixosModules.networking
+        nixosModules.packagemanagers
+        nixosModules.pipewire
+        nixosModules.printing
+        nixosModules.snowflakeos
+        ./configuration.nix
+      ];
+    };
+
+  node = {
+    # since we are using an overlay, we must make pkgs writable
+    pkgsReadOnly = false;
+
+    specialArgs = { inherit inputs; };
+  };
+
+  # disable only when working on testScript
+  skipTypeCheck = true;
+
+  testScript = ''
+    machine.start()
+    machine.wait_for_unit("multi-user.target")
+    machine.succeed("uname -a")
+    machine.succeed("echo Modules succesfully tested")
+  '';
+}
diff --git a/flake.nix b/flake.nix
index 0de920f..6a5e997 100644
--- a/flake.nix
+++ b/flake.nix
@@ -25,10 +25,19 @@
     };
   };
 
-  outputs = inputs:
+  outputs =
+    inputs:
     inputs.snowfall-lib.mkFlake {
       inherit inputs;
       channels-config.allowUnfree = true;
       src = ./.;
+
+      # Extra nix flags to set
+      outputs-builder = channels: {
+        formatter = channels.nixpkgs.nixfmt-tree;
+      };
+
+      # Default shell environment
+      alias.shells.default = "default";
     };
 }
diff --git a/modules/nixos/biosboot/default.nix b/modules/nixos/biosboot/default.nix
index 84ac01a..6c4e1a9 100644
--- a/modules/nixos/biosboot/default.nix
+++ b/modules/nixos/biosboot/default.nix
@@ -1,4 +1,10 @@
-{ options, config, lib, pkgs, ... }:
+{
+  options,
+  config,
+  lib,
+  pkgs,
+  ...
+}:
 
 with lib;
 let
diff --git a/modules/nixos/efiboot/default.nix b/modules/nixos/efiboot/default.nix
index 0118d05..26900a0 100644
--- a/modules/nixos/efiboot/default.nix
+++ b/modules/nixos/efiboot/default.nix
@@ -1,4 +1,10 @@
-{ options, config, lib, pkgs, ... }:
+{
+  options,
+  config,
+  lib,
+  pkgs,
+  ...
+}:
 
 with lib;
 let
@@ -8,19 +14,21 @@ in
 {
   options.modules.efiboot = with types; {
     bootloader = mkOption {
-      type = enum [ "grub" "systemd-boot" ];
+      type = enum [
+        "grub"
+        "systemd-boot"
+      ];
       default = "systemd-boot";
       description = "The kernel to use for booting.";
     };
   };
 
   config = mkMerge [
-    (mkIf (cfg.bootloader == "systemd-boot")
-      {
-        boot.loader.systemd-boot.enable = true;
-        boot.loader.efi.canTouchEfiVariables = true;
-        boot.loader.systemd-boot.editor = mkDefault false;    
-      })
+    (mkIf (cfg.bootloader == "systemd-boot") {
+      boot.loader.systemd-boot.enable = true;
+      boot.loader.efi.canTouchEfiVariables = true;
+      boot.loader.systemd-boot.editor = mkDefault false;
+    })
     (mkIf (cfg.bootloader == "grub") {
       boot.loader.systemd-boot.enable = false;
       boot.loader.grub.enable = true;
@@ -31,8 +39,9 @@ in
     {
       boot.tmp.cleanOnBoot = mkDefault true;
       # Temporary workaround for "random seed file is world accessible"
-      fileSystems.${efiSysMountPoint}.options =
-        mkIf (config.fileSystems.${efiSysMountPoint}.fsType == "vfat") [ "umask=0077" ];
+      fileSystems.${efiSysMountPoint}.options = mkIf (
+        config.fileSystems.${efiSysMountPoint}.fsType == "vfat"
+      ) [ "umask=0077" ];
     }
   ];
 }
diff --git a/modules/nixos/gnome/default.nix b/modules/nixos/gnome/default.nix
index acafff9..7eb4ea4 100644
--- a/modules/nixos/gnome/default.nix
+++ b/modules/nixos/gnome/default.nix
@@ -1,4 +1,10 @@
-{ options, config, lib, pkgs, ... }:
+{
+  options,
+  config,
+  lib,
+  pkgs,
+  ...
+}:
 
 with lib;
 let
@@ -6,10 +12,8 @@ let
 in
 {
   options.modules.gnome = with types; {
-    gsconnect.enable =
-      mkEnableOption "Enable KDE Connect integration";
-    removeUtils.enable =
-      mkEnableOption "Remove non-essential GNOME utilities";
+    gsconnect.enable = mkEnableOption "Enable KDE Connect integration";
+    removeUtils.enable = mkEnableOption "Remove non-essential GNOME utilities";
   };
 
   config = {
@@ -33,27 +37,30 @@ in
       enable = true;
     };
 
-    environment.gnome.excludePackages = mkIf cfg.removeUtils.enable (with pkgs.gnome; [
-      baobab
-      cheese
-      eog
-      epiphany
-      file-roller
-      gnome-calculator
-      gnome-calendar
-      gnome-characters
-      gnome-clocks
-      gnome-contacts
-      gnome-font-viewer
-      gnome-logs
-      gnome-maps
-      gnome-music
-      gnome-weather
-      pkgs.gnome-connections
-      pkgs.gnome-photos
-      pkgs.gnome-text-editor
-      simple-scan
-      totem
-    ]);
+    environment.gnome.excludePackages = mkIf cfg.removeUtils.enable (
+      with pkgs.gnome;
+      [
+        baobab
+        cheese
+        eog
+        epiphany
+        file-roller
+        gnome-calculator
+        gnome-calendar
+        gnome-characters
+        gnome-clocks
+        gnome-contacts
+        gnome-font-viewer
+        gnome-logs
+        gnome-maps
+        gnome-music
+        gnome-weather
+        pkgs.gnome-connections
+        pkgs.gnome-photos
+        pkgs.gnome-text-editor
+        simple-scan
+        totem
+      ]
+    );
   };
 }
diff --git a/modules/nixos/kernel/default.nix b/modules/nixos/kernel/default.nix
index 38e31d8..dacd10c 100644
--- a/modules/nixos/kernel/default.nix
+++ b/modules/nixos/kernel/default.nix
@@ -1,4 +1,9 @@
-{ config, lib, pkgs, ... }:
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
 with lib;
 {
   config = {
diff --git a/modules/nixos/networking/default.nix b/modules/nixos/networking/default.nix
index 388e7d3..9c4ec45 100644
--- a/modules/nixos/networking/default.nix
+++ b/modules/nixos/networking/default.nix
@@ -1,4 +1,9 @@
-{ config, lib, pkgs, ... }:
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
 with lib;
 {
   config = {
@@ -7,7 +12,10 @@ with lib;
     # Workaround for https://github.com/NixOS/nixpkgs/issues/180175
     systemd.services.NetworkManager-wait-online = {
       serviceConfig = {
-        ExecStart = [ "" "${pkgs.networkmanager}/bin/nm-online -q" ];
+        ExecStart = [
+          ""
+          "${pkgs.networkmanager}/bin/nm-online -q"
+        ];
       };
     };
   };
diff --git a/modules/nixos/packagemanagers/default.nix b/modules/nixos/packagemanagers/default.nix
index 2d30ce4..4064ccb 100644
--- a/modules/nixos/packagemanagers/default.nix
+++ b/modules/nixos/packagemanagers/default.nix
@@ -1,4 +1,10 @@
-{ options, config, lib, pkgs, ... }:
+{
+  options,
+  config,
+  lib,
+  pkgs,
+  ...
+}:
 
 with lib;
 let
@@ -6,8 +12,7 @@ let
 in
 {
   options.modules.packagemanagers = with types; {
-    appimage.enable =
-      mkEnableOption "Enable AppImage";
+    appimage.enable = mkEnableOption "Enable AppImage";
   };
 
   config = mkIf cfg.appimage.enable {
diff --git a/modules/nixos/pipewire/default.nix b/modules/nixos/pipewire/default.nix
index 6aa1aa9..1b1a2aa 100644
--- a/modules/nixos/pipewire/default.nix
+++ b/modules/nixos/pipewire/default.nix
@@ -1,4 +1,10 @@
-{ options, config, lib, pkgs, ... }:
+{
+  options,
+  config,
+  lib,
+  pkgs,
+  ...
+}:
 
 with lib;
 let
diff --git a/modules/nixos/snowflakeos/default.nix b/modules/nixos/snowflakeos/default.nix
index 954d3a8..a0a766d 100644
--- a/modules/nixos/snowflakeos/default.nix
+++ b/modules/nixos/snowflakeos/default.nix
@@ -1,4 +1,12 @@
-{ options, config, lib, pkgs, inputs, system, ... }:
+{
+  options,
+  config,
+  lib,
+  pkgs,
+  inputs,
+  system,
+  ...
+}:
 
 with lib;
 let
@@ -37,17 +45,17 @@ in
   config = mkMerge [
     (mkIf cfg.nixSoftwareCenter.enable {
       environment.systemPackages = with inputs; [
-        nix-software-center.packages.${system}.nix-software-center
+        nix-software-center.packages.${pkgs.stdenv.hostPlatform.system}.nix-software-center
       ];
     })
     (mkIf cfg.nixosConfEditor.enable {
       environment.systemPackages = with inputs; [
-        nixos-conf-editor.packages.${system}.nixos-conf-editor
+        nixos-conf-editor.packages.${pkgs.stdenv.hostPlatform.system}.nixos-conf-editor
       ];
     })
     (mkIf cfg.snowflakeosModuleManager.enable {
       environment.systemPackages = with inputs; [
-        snowflakeos-module-manager.packages.${system}.snowflakeos-module-manager
+        snowflakeos-module-manager.packages.${pkgs.stdenv.hostPlatform.system}.snowflakeos-module-manager
       ];
     })
     (mkIf cfg.binaryCompat.enable {
@@ -80,7 +88,7 @@ in
       snowflakeos.gnome.enable = mkDefault true;
 
       environment.systemPackages = with inputs; [
-        snow.packages.${system}.snow
+        snow.packages.${pkgs.stdenv.hostPlatform.system}.snow
         pkgs.git # For rebuiling with github flakes
       ];
 
@@ -93,27 +101,42 @@ in
       };
 
       # Reasonable Defaults
-      nix =
-        {
-          settings = {
-            experimental-features = [ "nix-command" "flakes" ];
-            substituters = [ "https://snowflakeos.cachix.org/" ];
-            trusted-public-keys = [
-              "snowflakeos.cachix.org-1:gXb32BL86r9bw1kBiw9AJuIkqN49xBvPd1ZW8YlqO70="
-            ];
-          } // (mapAttrsRecursive (_: mkDefault) {
-            connect-timeout = 5;
-            log-lines = 25;
-            min-free = 128000000;
-            max-free = 1000000000;
-            fallback = true;
-            warn-dirty = false;
-            auto-optimise-store = true;
-          });
-        } // (mapAttrsRecursive (_: mkDefault) {
-        linkInputs = true;
-        generateNixPathFromInputs = true;
-        generateRegistryFromInputs = true;
+      nix = {
+        settings = {
+          experimental-features = lib.mkDefault [
+            "nix-command"
+            "flakes"
+          ];
+          substituters = [ "https://snowflakeos.cachix.org/" ];
+          trusted-public-keys = [
+            "snowflakeos.cachix.org-1:gXb32BL86r9bw1kBiw9AJuIkqN49xBvPd1ZW8YlqO70="
+          ];
+
+          # trusted-users =
+          #   builtins.attrValues config.users.users
+          #   |> builtins.filter (attr: attr.isNormalUser)
+          #   |> map (u: u.name);
+        }
+        // (lib.mapAttrsRecursive (_: lib.mkDefault) {
+          connect-timeout = 5;
+          log-lines = 25;
+          min-free = 128000000;
+          max-free = 1000000000;
+          fallback = true;
+          warn-dirty = false;
+          auto-optimise-store = true;
+        });
+      }
+      // (lib.mapAttrsRecursive (_: lib.mkDefault) {
+        # flake-plus-utils provided options
+        # linkInputs = true;
+        # generateNixPathFromInputs = true;
+        # generateRegistryFromInputs = true;
+
+        # Manually implemented nixPath and registry
+        # Because flake-utils-plus options arent' working
+        registry = lib.mapAttrs (_: value: { flake = value; }) inputs;
+        nixPath = [ "/etc/nix/inputs" ];
       });
     })
   ];
diff --git a/modules/nixos/snowflakeos/gnome.nix b/modules/nixos/snowflakeos/gnome.nix
index 7f8617e..7f54746 100644
--- a/modules/nixos/snowflakeos/gnome.nix
+++ b/modules/nixos/snowflakeos/gnome.nix
@@ -1,4 +1,10 @@
-{ lib, config, options, pkgs, ... }:
+{
+  lib,
+  config,
+  options,
+  pkgs,
+  ...
+}:
 let
   nixos-background-info = pkgs.stdenv.mkDerivation { name = "nixos-background-info"; };
   snowflakeos-background-info = pkgs.writeTextFile rec {
diff --git a/modules/nixos/snowflakeos/graphical.nix b/modules/nixos/snowflakeos/graphical.nix
index 81a3dfa..c263446 100644
--- a/modules/nixos/snowflakeos/graphical.nix
+++ b/modules/nixos/snowflakeos/graphical.nix
@@ -1,4 +1,10 @@
-{ lib, config, options, pkgs, ... }:
+{
+  lib,
+  config,
+  options,
+  pkgs,
+  ...
+}:
 
 with lib;
 {
diff --git a/modules/nixos/snowflakeos/hardware.nix b/modules/nixos/snowflakeos/hardware.nix
index 707b049..2dccb75 100644
--- a/modules/nixos/snowflakeos/hardware.nix
+++ b/modules/nixos/snowflakeos/hardware.nix
@@ -1,4 +1,10 @@
-{ lib, config, options, pkgs, ... }:
+{
+  lib,
+  config,
+  options,
+  pkgs,
+  ...
+}:
 
 with lib;
 let
@@ -11,8 +17,7 @@ let
   '';
 in
 {
-  config = mkIf (config.hardware.nvidia.prime.offload.enable && config.snowflakeos.graphical.enable)
-    {
-      environment.systemPackages = [ nvidia-offload ];
-    };
+  config = mkIf (config.hardware.nvidia.prime.offload.enable && config.snowflakeos.graphical.enable) {
+    environment.systemPackages = [ nvidia-offload ];
+  };
 }
diff --git a/modules/nixos/snowflakeos/version.nix b/modules/nixos/snowflakeos/version.nix
index 0e73720..60de63e 100644
--- a/modules/nixos/snowflakeos/version.nix
+++ b/modules/nixos/snowflakeos/version.nix
@@ -1,15 +1,20 @@
-{ lib, config, options, pkgs, ... }:
+{
+  lib,
+  config,
+  options,
+  pkgs,
+  ...
+}:
 
 with lib;
 let
   cfg = config.system.nixos;
   needsEscaping = s: null != builtins.match "[a-zA-Z0-9]+" s;
   escapeIfNeccessary = s: if needsEscaping s then s else ''"${escape [ "\$" "\"" "\\" "\`" ] s}"'';
-  attrsToText = attrs:
-    concatStringsSep "\n"
-      (
-        mapAttrsToList (n: v: ''${n}=${escapeIfNeccessary (toString v)}'') attrs
-      ) + "\n";
+  attrsToText =
+    attrs:
+    concatStringsSep "\n" (mapAttrsToList (n: v: "${n}=${escapeIfNeccessary (toString v)}") attrs)
+    + "\n";
   osReleaseContents = {
     NAME = "SnowflakeOS";
     ID = "snowflakeos";
diff --git a/packages/nix-software-center/default.nix b/packages/nix-software-center/default.nix
index fd812c9..6b099fb 100644
--- a/packages/nix-software-center/default.nix
+++ b/packages/nix-software-center/default.nix
@@ -1,2 +1 @@
-{ inputs, system }:
-inputs.nix-software-center.packages.${system}.nix-software-center
+{ inputs, system }: inputs.nix-software-center.packages.${system}.nix-software-center
diff --git a/packages/nixos-conf-editor/default.nix b/packages/nixos-conf-editor/default.nix
index 97dc048..41c9a29 100644
--- a/packages/nixos-conf-editor/default.nix
+++ b/packages/nixos-conf-editor/default.nix
@@ -1,2 +1 @@
-{ inputs, system }:
-inputs.nixos-conf-editor.packages.${system}.nixos-conf-editor
+{ inputs, system }: inputs.nixos-conf-editor.packages.${system}.nixos-conf-editor
diff --git a/packages/snow/default.nix b/packages/snow/default.nix
index 3266197..f932352 100644
--- a/packages/snow/default.nix
+++ b/packages/snow/default.nix
@@ -1,2 +1,6 @@
-{ inputs, system }:
-inputs.snow.packages.${system}.snow
+{
+  inputs,
+  system,
+  pkgs,
+}:
+inputs.snow.packages.${pkgs.stdenv.hostPlatform.system}.snow
diff --git a/packages/snowflakeos-module-manager/default.nix b/packages/snowflakeos-module-manager/default.nix
index a8f5513..49af81d 100644
--- a/packages/snowflakeos-module-manager/default.nix
+++ b/packages/snowflakeos-module-manager/default.nix
@@ -1,2 +1,2 @@
-{ inputs, system }:
-inputs.snowflakeos-module-manager.packages.${system}.snowflakeos-module-manager
+{ inputs, system, pkgs }:
+inputs.snowflakeos-module-manager.packages.${pkgs.stdenv.hostPlatform.system}.snowflakeos-module-manager
diff --git a/shells/default/default.nix b/shells/default/default.nix
new file mode 100644
index 0000000..95ba9f7
--- /dev/null
+++ b/shells/default/default.nix
@@ -0,0 +1,15 @@
+{
+  mkShell,
+  nixd,
+  statix,
+  deadnix,
+  nixfmt,
+}:
+mkShell {
+  nativeBuildInputs = [
+    nixd
+    statix
+    deadnix
+    nixfmt
+  ];
+}