diff --git a/inventories/default.nix b/inventories/default.nix
index 537658a..461ae1d 100644
--- a/inventories/default.nix
+++ b/inventories/default.nix
@@ -382,9 +382,9 @@
                         name = "matrix";
                         webhook_configs = [
                           {
-                            url = "http://localhost:3000/alerts?secret=$$KUROIRIS_SECRET";
+                            # url = "http://localhost:3000/alerts?secret=$$KUROIRIS_SECRET";
+                            url_file = "";
                             send_resolved = true;
-
                           }
                         ];
                       }
diff --git a/machines/rigel/configuration.nix b/machines/rigel/configuration.nix
index 5da61e2..ba716a7 100644
--- a/machines/rigel/configuration.nix
+++ b/machines/rigel/configuration.nix
@@ -9,10 +9,13 @@
     files.envFile.secret = true;
     files.matrix-alertmanager-token.secret = true;
     files.matrix-alertmanager-secret.secret = true;
+    files.matrix-alertmanager-urlfile.secret = true;
     script = ''
       echo "" > $out/envFile
       echo "" > $out/matrix-alertmanager-token
       openssl rand -hex 32 > "$out"/matrix-alertmanager-secret
+
+      echo "http://localhost:3000/alerts?secret=$(cat $out/matrix-alertmanager-secret)" > $out/matrix-alertmanager-urlfile
     '';
     runtimeInputs = [
       pkgs.openssl