diff --git a/README.md b/README.md
index 2181344..6d966be 100644
--- a/README.md
+++ b/README.md
@@ -84,7 +84,36 @@ Default speed stats path:
 
 For NixOS notes, see `DEV_SETUP.md`.
 
-## systemd user service
+## nixos module
+
+This flake now exports:
+
+- `packages.<system>.default` (contains `gsf` + `gsfd`)
+- `nixosModules.default` (`hardware.gsf`)
+
+Example:
+
+```nix
+# flake input
+inputs.gsf.url = "github:<you>/gotta-scroll-fast";
+
+# module import + config
+{
+  imports = [ inputs.gsf.nixosModules.default ];
+
+  hardware.gsf = {
+    enable = true;
+    device = "/dev/input/by-id/usb-...-event-mouse";
+    inputGroupUsers = [ "thomasgl" ];
+    # extraArgs = [ "--match-name" "ploopy" ];
+  };
+}
+```
+
+`hardware.gsf` intentionally does **not** provide declarative accel parameters.
+Manage those via your dotfiles (`~/.config/gsf/config.json`) and `gsf` CLI/TUI.
+
+## systemd user service (manual alternative)
 
 A starting unit file exists at:
 
diff --git a/flake.nix b/flake.nix
index 76b5578..4fb0098 100644
--- a/flake.nix
+++ b/flake.nix
@@ -10,13 +10,33 @@
     let
       eachSystem = flake-utils.lib.eachDefaultSystem;
     in
-    eachSystem (system:
+    {
+      nixosModules.default = import ./nix/module.nix;
+    }
+    // eachSystem (system:
       let
         pkgs = import nixpkgs {
           inherit system;
           config.allowUnfree = false;
         };
+
+        gsfTools = pkgs.callPackage ./nix/package.nix {
+          src = self;
+        };
       in {
+        packages.default = gsfTools;
+        packages.gsf-tools = gsfTools;
+
+        apps.gsf = flake-utils.lib.mkApp {
+          drv = gsfTools;
+          name = "gsf";
+        };
+
+        apps.gsfd = flake-utils.lib.mkApp {
+          drv = gsfTools;
+          name = "gsfd";
+        };
+
         devShells.default = pkgs.mkShell {
           packages = with pkgs; [
             rustc
diff --git a/nix/module.nix b/nix/module.nix
new file mode 100644
index 0000000..1fba052
--- /dev/null
+++ b/nix/module.nix
@@ -0,0 +1,98 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+let
+  cfg = config.hardware.gsf;
+
+  defaultPackage = pkgs.callPackage ./package.nix {
+    src = ../.;
+  };
+
+  extraArgs = lib.concatMapStringsSep " " lib.escapeShellArg cfg.extraArgs;
+in
+{
+  options.hardware.gsf = {
+    enable = lib.mkEnableOption "gotta-scroll-fast daemon";
+
+    package = lib.mkOption {
+      type = lib.types.package;
+      default = defaultPackage;
+      description = "Package providing `gsf` and `gsfd` binaries.";
+    };
+
+    installTools = lib.mkOption {
+      type = lib.types.bool;
+      default = true;
+      description = "Install gsf/gsfd package in system packages.";
+    };
+
+    autoStart = lib.mkOption {
+      type = lib.types.bool;
+      default = true;
+      description = "Start gsfd as a systemd user service.";
+    };
+
+    device = lib.mkOption {
+      type = lib.types.nullOr lib.types.str;
+      default = null;
+      example = "/dev/input/by-id/usb-Ploopy_...-event-mouse";
+      description = "Input event device path passed to `gsfd --device`.";
+    };
+
+    extraArgs = lib.mkOption {
+      type = lib.types.listOf lib.types.str;
+      default = [];
+      description = "Extra arguments passed to gsfd.";
+    };
+
+    enableUinput = lib.mkOption {
+      type = lib.types.bool;
+      default = true;
+      description = "Enable /dev/uinput support and permissions.";
+    };
+
+    inputGroupUsers = lib.mkOption {
+      type = lib.types.listOf lib.types.str;
+      default = [];
+      example = ["thomasgl"];
+      description = "Users to add to the `input` group for /dev/input and /dev/uinput access.";
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    assertions = [
+      {
+        assertion = !cfg.autoStart || cfg.device != null;
+        message = "hardware.gsf.device must be set when hardware.gsf.autoStart = true";
+      }
+    ];
+
+    environment.systemPackages = lib.mkIf cfg.installTools [cfg.package];
+
+    boot.kernelModules = lib.mkIf cfg.enableUinput ["uinput"];
+
+    services.udev.extraRules = lib.mkIf cfg.enableUinput ''
+      KERNEL=="uinput", MODE="0660", GROUP="input"
+    '';
+
+    users.users = lib.mkIf (cfg.inputGroupUsers != []) (
+      lib.genAttrs cfg.inputGroupUsers (_: {
+        extraGroups = ["input"];
+      })
+    );
+
+    systemd.user.services.gsfd = lib.mkIf cfg.autoStart {
+      description = "gotta-scroll-fast daemon";
+      wantedBy = ["default.target"];
+      after = ["graphical-session.target"];
+      serviceConfig = {
+        ExecStart = "${cfg.package}/bin/gsfd --device ${lib.escapeShellArg cfg.device}${lib.optionalString (cfg.extraArgs != []) " ${extraArgs}"}";
+        Restart = "on-failure";
+        RestartSec = 1;
+      };
+    };
+  };
+}
diff --git a/nix/package.nix b/nix/package.nix
new file mode 100644
index 0000000..e1b7fa9
--- /dev/null
+++ b/nix/package.nix
@@ -0,0 +1,33 @@
+{
+  lib,
+  pkgs,
+  src ? ../.,
+}:
+let
+  daemonToml = builtins.fromTOML (builtins.readFile (src + "/daemon/Cargo.toml"));
+in
+pkgs.rustPlatform.buildRustPackage rec {
+  pname = "gsf-tools";
+  version = daemonToml.package.version;
+
+  inherit src;
+  cargoLock.lockFile = src + "/Cargo.lock";
+
+  cargoBuildFlags = ["-p" "gsf-cli" "-p" "gsf-daemon"];
+
+  doCheck = false;
+
+  installPhase = ''
+    runHook preInstall
+    mkdir -p $out/bin
+    cp target/release/gsf $out/bin/
+    cp target/release/gsfd $out/bin/
+    runHook postInstall
+  '';
+
+  meta = with lib; {
+    description = "gotta-scroll-fast tools (gsf + gsfd)";
+    license = licenses.gpl2Plus;
+    platforms = platforms.linux;
+  };
+}