diff --git a/common.nix b/common.nix
new file mode 100644
index 0000000..e11d919
--- /dev/null
+++ b/common.nix
@@ -0,0 +1,35 @@
+{ inputs, config, lib, pkgs, ... }:
+
+with lib;
+with lib.my;
+{
+  imports =
+    [ inputs.home-manager.nixosModules.home-manager ];
+  # ++ (mapModulesRec' (toString ./modules) import);
+
+  nix = {
+    package = pkgs.nixFlakes;
+    extraOptions = "experimental-features = nix-command flakes";
+    nixPath = [
+      "nixpkgs=${inputs.nixpkgs-unstable}"
+    ];
+    settings = {
+      substituters = [
+        "https://nix-community.cachix.org"
+        "http://cache.banditlair.com"
+        "https://cache.nixos.org/"
+      ];
+      trusted-public-keys = [
+        "nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs="
+        "cache.banditlair.com:4zk7iDvzKh6VN+LxzKIGcVPKgL5dLeyEt2ydrgx4o8c="
+      ];
+      auto-optimise-store = true;
+    };
+  };
+  system.configurationRevision = with inputs; mkIf (self ? rev) self.rev;
+
+  environment.systemPackages = with pkgs; [
+    git
+    vim
+  ];
+}
diff --git a/flake.nix b/flake.nix
index 706d924..6c59fef 100644
--- a/flake.nix
+++ b/flake.nix
@@ -6,179 +6,38 @@
     nix-doom-emacs.url = "github:nix-community/nix-doom-emacs";
   };
 
-  outputs = { self, home-manager, nixpkgs, nixpkgs-unstable, nix-doom-emacs }:
+  outputs = inputs @ { self, home-manager, nixpkgs, nixpkgs-unstable, ... }:
     let
+      inherit (lib.my) mapModules mapModulesRec mapHosts;
+
       system = "x86_64-linux";
-      commonModuleArgs = { pkgs, ... }: {
-        _module.args.pkgs-unstable = import nixpkgs-unstable {
-          inherit (pkgs.stdenv.targetPlatform) system;
-          overlays = [ (import ./overlay.nix) ];
-          config.allowUnfreePredicate = pkg: builtins.elem (pkgs.lib.getName pkg) [
-            "corefonts"
-            "steam"
-            "steam-original"
-            "steam-run"
-          ];
-        };
+
+      mkPkgs = pkgs: extraOverlays: import pkgs {
+        inherit system;
+        config.allowUnfreePredicate = pkg: builtins.elem (pkgs.lib.getName pkg) [
+          "corefonts"
+          "steam"
+          "steam-original"
+          "steam-run"
+        ];
+        overlays = extraOverlays ++ (pkgs.lib.attrValues self.overlays);
       };
+      pkgs = mkPkgs nixpkgs [ self.overlay ];
+      pkgs-unstable = mkPkgs nixpkgs-unstable [ ];
+
+      lib = nixpkgs.lib.extend
+        (self: super: { my = import ./lib { inherit pkgs inputs; lib = self; }; });
     in
     {
-      nixosConfigurations.nixos-desktop = nixpkgs.lib.nixosSystem {
-        inherit system;
-        specialArgs = { inherit nixpkgs; inherit nixpkgs-unstable; inherit nix-doom-emacs; };
-        modules =
-          [
-            home-manager.nixosModules.home-manager
-            commonModuleArgs
-            ./hardware/desktop.nix
-            ./profiles/base.nix
-            ./users
-            (
-              {
-                networking.hostName = "nixos-desktop";
-                # Allow to externally control MPD
-                networking.firewall.allowedTCPPorts = [ 6600 ];
+      lib = lib.my;
 
-                nix.registry.nixpkgs.flake = nixpkgs;
-
-                system.stateVersion = "19.09";
-              }
-            )
-          ];
+      overlay = final: prev: {
+        unstable = pkgs-unstable;
       };
 
-      nixosConfigurations.froidmpa-laptop = nixpkgs.lib.nixosSystem {
-        inherit system;
-        specialArgs = { inherit nixpkgs; inherit nixpkgs-unstable; inherit nix-doom-emacs; };
-        modules =
-          [
-            home-manager.nixosModules.home-manager
-            commonModuleArgs
-            ./hardware/clevo-nl51ru.nix
-            ./profiles/base.nix
-            ./users
-            (
-              {
-                networking.hostName = "froidmpa-laptop";
+      overlays = { my = (import ./overlay.nix); };
 
-                nix.registry.nixpkgs.flake = nixpkgs;
+      nixosConfigurations = mapHosts ./hosts { };
 
-                home-manager.users.froidmpa = { pkgs, config, ... }: {
-                  services.network-manager-applet.enable = true;
-                  services.blueman-applet.enable = true;
-                  services.grobi = {
-                    enable = true;
-                    executeAfter = [ "${pkgs.systemd}/bin/systemctl --user restart stalonetray" "${pkgs.feh}/bin/feh --bg-fill ~/.wallpaper.png" ];
-                    rules = [
-                      {
-                        name = "External HDMI";
-                        outputs_connected = [ "HDMI-1" ];
-                        configure_single = "HDMI-1";
-                        primary = true;
-                        atomic = true;
-                      }
-                      {
-                        name = "Primary";
-                        configure_single = "eDP";
-                      }
-                    ];
-                  };
-                };
-
-                system.stateVersion = "21.05";
-              }
-            )
-
-          ];
-      };
-
-      nixosConfigurations.rpi3 = nixpkgs.lib.nixosSystem {
-        system = "aarch64-linux";
-        modules =
-          [
-            (
-              { pkgs, ... }: {
-                networking.hostName = "rpi3";
-
-                nix.registry.nixpkgs.flake = nixpkgs;
-
-                boot.loader.grub.enable = false;
-                boot.loader.generic-extlinux-compatible.enable = true;
-                boot.kernelParams = [ "cma=256M" ];
-
-                fileSystems."/" =
-                  {
-                    device = "/dev/disk/by-label/NIXOS_SD";
-                    fsType = "ext4";
-                  };
-
-                swapDevices = [{ device = "/swapfile"; size = 1024; }];
-
-                services.openssh.enable = true;
-                users.users.root.openssh.authorizedKeys.keyFiles = [
-                  ./ssh_keys/phfroidmont-desktop.pub
-                  ./ssh_keys/phfroidmont-laptop.pub
-                ];
-
-                services.adguardhome = {
-                  enable = true;
-
-                  host = "0.0.0.0";
-                  port = 80;
-                  openFirewall = true;
-
-                  mutableSettings = false;
-
-                  settings = {
-                    auth_attempts = 5;
-                    block_auth_min = 15;
-                    dns = {
-                      bind_host = "0.0.0.0";
-                      port = 53;
-                      statistics_interval = 90;
-                      querylog_enabled = true;
-                      querylog_interval = "2160h";
-                      upstream_dns = [
-                        "tls://doh.mullvad.net"
-                        "[/lan/]192.168.1.1"
-                        "[//]192.168.1.1"
-                      ];
-                      local_ptr_upstreams = [ "192.168.1.1" ];
-                      use_private_ptr_resolvers = true;
-                      resolve_clients = true;
-                      bootstrap_dns = [ "9.9.9.10" ];
-                      rewrites = [
-                        {
-                          domain = "rpi3";
-                          answer = "192.168.1.2";
-                        }
-                        {
-                          domain = "rpi3.lan";
-                          answer = "192.168.1.2";
-                        }
-                      ];
-                    };
-                  };
-                };
-
-                networking.firewall.allowedTCPPorts = [ 53 ];
-                networking.firewall.allowedUDPPorts = [ 53 ];
-
-                environment.systemPackages = with pkgs; [
-                  vim
-                  htop
-                ];
-
-                nix = {
-                  nixPath = [
-                    "nixpkgs=${nixpkgs}"
-                  ];
-                };
-
-                system.stateVersion = "22.05";
-              }
-            )
-          ];
-      };
     };
 }
diff --git a/hosts/froidmpa-laptop/default.nix b/hosts/froidmpa-laptop/default.nix
new file mode 100644
index 0000000..172618b
--- /dev/null
+++ b/hosts/froidmpa-laptop/default.nix
@@ -0,0 +1,32 @@
+{ pkgs, config, lib, ... }:
+{
+  imports = [
+    ./hardware-configuration.nix
+    ../../profiles/base.nix
+    ../../users
+  ];
+
+  home-manager.users.froidmpa = { pkgs, config, ... }: {
+    services.network-manager-applet.enable = true;
+    services.blueman-applet.enable = true;
+    services.grobi = {
+      enable = true;
+      executeAfter = [ "${pkgs.systemd}/bin/systemctl --user restart stalonetray" "${pkgs.feh}/bin/feh --bg-fill ~/.wallpaper.png" ];
+      rules = [
+        {
+          name = "External HDMI";
+          outputs_connected = [ "HDMI-1" ];
+          configure_single = "HDMI-1";
+          primary = true;
+          atomic = true;
+        }
+        {
+          name = "Primary";
+          configure_single = "eDP";
+        }
+      ];
+    };
+  };
+
+  system.stateVersion = "21.05";
+}
diff --git a/hardware/clevo-nl51ru.nix b/hosts/froidmpa-laptop/hardware-configuration.nix
similarity index 100%
rename from hardware/clevo-nl51ru.nix
rename to hosts/froidmpa-laptop/hardware-configuration.nix
diff --git a/hosts/nixos-desktop/default.nix b/hosts/nixos-desktop/default.nix
new file mode 100644
index 0000000..9ff9d94
--- /dev/null
+++ b/hosts/nixos-desktop/default.nix
@@ -0,0 +1,13 @@
+{ pkgs, config, lib, ... }:
+{
+  imports = [
+    ./hardware-configuration.nix
+    ../../profiles/base.nix
+    ../../users
+  ];
+
+  # Allow to externally control MPD
+  networking.firewall.allowedTCPPorts = [ 6600 ];
+
+  system.stateVersion = "19.09";
+}
diff --git a/hardware/desktop.nix b/hosts/nixos-desktop/hardware-configuration.nix
similarity index 100%
rename from hardware/desktop.nix
rename to hosts/nixos-desktop/hardware-configuration.nix
diff --git a/hosts/rpi3/default.nix b/hosts/rpi3/default.nix
new file mode 100644
index 0000000..2a66608
--- /dev/null
+++ b/hosts/rpi3/default.nix
@@ -0,0 +1,71 @@
+{ pkgs, config, lib, ... }:
+{
+
+  boot.loader.grub.enable = false;
+  boot.loader.generic-extlinux-compatible.enable = true;
+  boot.kernelParams = [ "cma=256M" ];
+
+  fileSystems."/" =
+    {
+      device = "/dev/disk/by-label/NIXOS_SD";
+      fsType = "ext4";
+    };
+
+  swapDevices = [{ device = "/swapfile"; size = 1024; }];
+
+  services.openssh.enable = true;
+  users.users.root.openssh.authorizedKeys.keyFiles = [
+    ../../ssh_keys/phfroidmont-desktop.pub
+    ../../ssh_keys/phfroidmont-laptop.pub
+  ];
+
+  services.adguardhome = {
+    enable = true;
+
+    host = "0.0.0.0";
+    port = 80;
+    openFirewall = true;
+
+    mutableSettings = false;
+
+    settings = {
+      auth_attempts = 5;
+      block_auth_min = 15;
+      dns = {
+        bind_host = "0.0.0.0";
+        port = 53;
+        statistics_interval = 90;
+        querylog_enabled = true;
+        querylog_interval = "2160h";
+        upstream_dns = [
+          "tls://doh.mullvad.net"
+          "[/lan/]192.168.1.1"
+          "[//]192.168.1.1"
+        ];
+        local_ptr_upstreams = [ "192.168.1.1" ];
+        use_private_ptr_resolvers = true;
+        resolve_clients = true;
+        bootstrap_dns = [ "9.9.9.10" ];
+        rewrites = [
+          {
+            domain = "rpi3";
+            answer = "192.168.1.2";
+          }
+          {
+            domain = "rpi3.lan";
+            answer = "192.168.1.2";
+          }
+        ];
+      };
+    };
+  };
+
+  networking.firewall.allowedTCPPorts = [ 53 ];
+  networking.firewall.allowedUDPPorts = [ 53 ];
+
+  environment.systemPackages = with pkgs; [
+    htop
+  ];
+
+  system.stateVersion = "22.05";
+}
diff --git a/lib/attrs.nix b/lib/attrs.nix
new file mode 100644
index 0000000..0f8ebd1
--- /dev/null
+++ b/lib/attrs.nix
@@ -0,0 +1,26 @@
+{ lib, ... }:
+
+with builtins;
+with lib;
+rec {
+  # attrsToList
+  attrsToList = attrs:
+    mapAttrsToList (name: value: { inherit name value; }) attrs;
+
+  # mapFilterAttrs ::
+  #   (name -> value -> bool)
+  #   (name -> value -> { name = any; value = any; })
+  #   attrs
+  mapFilterAttrs = pred: f: attrs: filterAttrs pred (mapAttrs' f attrs);
+
+  # Generate an attribute set by mapping a function over a list of values.
+  genAttrs' = values: f: listToAttrs (map f values);
+
+  # anyAttrs :: (name -> value -> bool) attrs
+  anyAttrs = pred: attrs:
+    any (attr: pred attr.name attr.value) (attrsToList attrs);
+
+  # countAttrs :: (name -> value -> bool) attrs
+  countAttrs = pred: attrs:
+    count (attr: pred attr.name attr.value) (attrsToList attrs);
+}
diff --git a/lib/default.nix b/lib/default.nix
new file mode 100644
index 0000000..a275c09
--- /dev/null
+++ b/lib/default.nix
@@ -0,0 +1,18 @@
+{ inputs, lib, pkgs, ... }:
+
+let
+  inherit (lib) makeExtensible attrValues foldr;
+  inherit (modules) mapModules;
+
+  modules = import ./modules.nix {
+    inherit lib;
+    self.attrs = import ./attrs.nix { inherit lib; self = { }; };
+  };
+
+  mylib = makeExtensible (self:
+    with self; mapModules ./.
+      (file: import file { inherit self lib pkgs inputs; }));
+in
+mylib.extend
+  (self: super:
+  foldr (a: b: a // b) { } (attrValues super))
diff --git a/lib/modules.nix b/lib/modules.nix
new file mode 100644
index 0000000..ef7c289
--- /dev/null
+++ b/lib/modules.nix
@@ -0,0 +1,54 @@
+{ self, lib, ... }:
+
+let
+  inherit (builtins) attrValues readDir pathExists concatLists;
+  inherit (lib) id mapAttrsToList filterAttrs hasPrefix hasSuffix nameValuePair removeSuffix;
+  inherit (self.attrs) mapFilterAttrs;
+in
+rec {
+  mapModules = dir: fn:
+    mapFilterAttrs
+      (n: v:
+        v != null &&
+        !(hasPrefix "_" n))
+      (n: v:
+        let path = "${toString dir}/${n}"; in
+        if v == "directory" && pathExists "${path}/default.nix"
+        then nameValuePair n (fn path)
+        else if v == "regular" &&
+          n != "default.nix" &&
+          hasSuffix ".nix" n
+        then nameValuePair (removeSuffix ".nix" n) (fn path)
+        else nameValuePair "" null)
+      (readDir dir);
+
+  mapModules' = dir: fn:
+    attrValues (mapModules dir fn);
+
+  mapModulesRec = dir: fn:
+    mapFilterAttrs
+      (n: v:
+        v != null &&
+        !(hasPrefix "_" n))
+      (n: v:
+        let path = "${toString dir}/${n}"; in
+        if v == "directory"
+        then nameValuePair n (mapModulesRec path fn)
+        else if v == "regular" && n != "default.nix" && hasSuffix ".nix" n
+        then nameValuePair (removeSuffix ".nix" n) (fn path)
+        else nameValuePair "" null)
+      (readDir dir);
+
+  mapModulesRec' = dir: fn:
+    let
+      dirs =
+        mapAttrsToList
+          (k: _: "${dir}/${k}")
+          (filterAttrs
+            (n: v: v == "directory" && !(hasPrefix "_" n))
+            (readDir dir));
+      files = attrValues (mapModules dir id);
+      paths = files ++ concatLists (map (d: mapModulesRec' d id) dirs);
+    in
+    map fn paths;
+}
diff --git a/lib/nixos.nix b/lib/nixos.nix
new file mode 100644
index 0000000..e904ecd
--- /dev/null
+++ b/lib/nixos.nix
@@ -0,0 +1,26 @@
+{ inputs, lib, pkgs, ... }:
+
+with lib;
+with lib.my;
+let sys = "x86_64-linux";
+in {
+  mkHost = path: attrs @ { system ? sys, ... }:
+    nixosSystem {
+      inherit system;
+      specialArgs = { inherit lib inputs system; };
+      modules = [
+        {
+          nixpkgs.pkgs = pkgs;
+          nix.registry.nixpkgs.flake = inputs.nixpkgs;
+          networking.hostName = mkDefault (removeSuffix ".nix" (baseNameOf path));
+        }
+        (filterAttrs (n: v: !elem n [ "system" ]) attrs)
+        ../common.nix
+        (import path)
+      ];
+    };
+
+  mapHosts = dir: attrs @ { system ? system, ... }:
+    mapModules dir
+      (hostPath: mkHost hostPath attrs);
+}
diff --git a/modules/belgian-eid.nix b/modules/belgian-eid.nix
index 17fa5fa..9a138e9 100644
--- a/modules/belgian-eid.nix
+++ b/modules/belgian-eid.nix
@@ -1,7 +1,7 @@
-{ config, lib, pkgs, pkgs-unstable, ... }:
+{ config, lib, pkgs, ... }:
 {
   services.pcscd.enable = true;
-  environment.systemPackages = with pkgs-unstable; [
+  environment.systemPackages = with pkgs.unstable; [
     eid-mw
   ];
 }
diff --git a/modules/system.nix b/modules/system.nix
index 2da2aaf..443ab83 100644
--- a/modules/system.nix
+++ b/modules/system.nix
@@ -1,42 +1,11 @@
-{ config, lib, pkgs, nixpkgs, pkgs-unstable, nixpkgs-unstable, ... }:
+{ config, lib, pkgs, nixpkgs, ... }:
 {
 
-  nix = {
-    package = pkgs.nixUnstable;
-    settings = {
-      extra-sandbox-paths = [
-        "/var/keys/netrc"
-      ];
-      substituters = [
-        "http://cache.banditlair.com"
-        "https://cache.nixos.org/"
-      ];
-      trusted-public-keys = [
-        "cache.banditlair.com:4zk7iDvzKh6VN+LxzKIGcVPKgL5dLeyEt2ydrgx4o8c="
-      ];
-    };
-
-    extraOptions = ''
-      experimental-features = nix-command flakes
-    '';
-    nixPath = [
-      "nixpkgs=${nixpkgs-unstable}"
-    ];
-  };
-
-  environment.systemPackages = with pkgs-unstable; [
+  environment.systemPackages = with pkgs.unstable; [
     wget
     inetutils
-    openvpn
-    openfortivpn
-
     man
 
-    dos2unix
-
-    vim
-    git
-    git-lfs
     zip
     unzip
 
@@ -52,7 +21,7 @@
     dnsutils
   ];
   fonts = {
-    fonts = with pkgs-unstable; [
+    fonts = with pkgs.unstable; [
       corefonts # Microsoft free fonts
       meslo-lgs-nf
     ];
diff --git a/users/default.nix b/users/default.nix
index d118019..12bc9ec 100644
--- a/users/default.nix
+++ b/users/default.nix
@@ -1,8 +1,8 @@
-{ config, lib, pkgs, pkgs-unstable, nix-doom-emacs, ... }:
+{ inputs, config, lib, pkgs, ... }:
 {
 
   environment.pathsToLink = [ "/share/zsh" ];
-  home-manager.users.froidmpa = { pkgs, config, ... }: {
+  home-manager.users.froidmpa = { config, ... }: {
 
     imports = [
       ./froidmpa/alacritty.nix
@@ -12,7 +12,7 @@
       ./froidmpa/htop.nix
       ./froidmpa/zsh.nix
       ./froidmpa/vscode.nix
-      nix-doom-emacs.hmModule
+      inputs.nix-doom-emacs.hmModule
     ];
 
     xsession = {
@@ -255,7 +255,7 @@
         };
       };
 
-      packages = with pkgs-unstable; [
+      packages = with pkgs.unstable; [
         haskellPackages.xmobar
         i3lock
         ncmpcpp
@@ -317,7 +317,7 @@
     systemd.user.services.activitywatch = {
       Unit.Description = "Start ActivityWatch";
       Service.Type = "simple";
-      Service.ExecStart = "${pkgs-unstable.activitywatch-bin}/bin/aw-server";
+      Service.ExecStart = "${pkgs.unstable.activitywatch-bin}/bin/aw-server";
       Install.WantedBy = [ "default.target" ];
       Service.Restart = "on-failure";
       Service.RestartSec = 5;
@@ -325,7 +325,7 @@
     systemd.user.services.activitywatch-afk = {
       Unit.Description = "Start ActivityWatch AFK";
       Service.Type = "simple";
-      Service.ExecStart = "${pkgs-unstable.activitywatch-bin}/bin/aw-watcher-afk";
+      Service.ExecStart = "${pkgs.unstable.activitywatch-bin}/bin/aw-watcher-afk";
       Install.WantedBy = [ "default.target" ];
       Service.Restart = "on-failure";
       Service.RestartSec = 5;
@@ -333,7 +333,7 @@
     systemd.user.services.activitywatch-window = {
       Unit.Description = "Start ActivityWatch Window";
       Service.Type = "simple";
-      Service.ExecStart = "${pkgs-unstable.activitywatch-bin}/bin/aw-watcher-window";
+      Service.ExecStart = "${pkgs.unstable.activitywatch-bin}/bin/aw-watcher-window";
       Install.WantedBy = [ "default.target" ];
       Service.Restart = "on-failure";
       Service.RestartSec = 5;