diff --git a/src/dda/backup/monitoring/domain.clj b/src/dda/backup/monitoring/domain.clj
new file mode 100644
index 0000000..0d12fca
--- /dev/null
+++ b/src/dda/backup/monitoring/domain.clj
@@ -0,0 +1 @@
+(ns dda.backup.monitoring.domain)
\ No newline at end of file
diff --git a/test/dda/backup/monitoring/domain_test.clj b/test/dda/backup/monitoring/domain_test.clj
new file mode 100644
index 0000000..b19182a
--- /dev/null
+++ b/test/dda/backup/monitoring/domain_test.clj
@@ -0,0 +1,22 @@
+(ns dda.backup.monitoring.domain-test
+  (:require
+   [clojure.test :refer [deftest is are testing run-tests]]
+   [clojure.spec.test.alpha :as st]
+   [dda.backup.monitoring.domain :as cut]))
+
+(deftest should-calculate-backup-files-command
+  (is (= [{:baseLabels {:__name__ "backup_size"},
+           :docstring "Backup size in MB",
+           :metric {:type "gauge",
+                    :value [{:labels
+                             {:app_name "c4k-forgejo"
+                              :fqdn "repo.prod.meissa.de"
+                              :restic_repo "s3://..."},
+                             :value 123}]}}]
+         (cut/backup-files-command {:restic-repository "repo"
+                                    :backup-path "dir-at-repo"
+                                    :execution-directory "dir-to-backup"
+                                    :days-to-keep 39
+                                    :months-to-keep 3
+                                    :files ["file2" "file2"]}))))
+