diff --git a/nix/buildAllNixosConfigurations.nix b/nix/buildAllNixosConfigurations.nix
new file mode 100644
index 0000000..f6d891a
--- /dev/null
+++ b/nix/buildAllNixosConfigurations.nix
@@ -0,0 +1,30 @@
+# buid all system locally is part of `nix flake check` with  this flake parrt.
+# todo make this an application : `nix run .#buildAllNixosConfigurations`
+{ inputs, self, ... }:
+{
+  perSystem =
+    {
+      pkgs,
+      system,
+      lib,
+      ...
+    }:
+    with lib;
+    {
+      checks =
+        let
+          all = attrNames self.nixosConfigurations;
+          linkFor = sys: "ln -s ${self.nixosConfigurations.${sys}.config.system.build.toplevel} $out/${sys}";
+          links = filt: builtins.concatStringsSep "\n" (map linkFor (filter (name: filt name) all));
+          toplevels =
+            filt:
+            pkgs.runCommandLocal "toplevels" { } ''
+              mkdir $out
+              ${links filt}
+            '';
+        in
+        {
+          buildAllNixosConfigurations = toplevels (_: true);
+        };
+    };
+}