diff --git a/hydra/default.nix b/hydra/default.nix
index 635d38c..552655e 100644
--- a/hydra/default.nix
+++ b/hydra/default.nix
@@ -2,4 +2,9 @@
   flake.hydraJobs = {
     packages = self.packages; 
   };
+  perSystem = {pkgs, ...}: {
+    packages.hydraHook = pkgs.writeScript "hook" ''
+      echo ciao
+    ''; 
+  };
 }