diff --git a/deps.edn b/deps.edn
index 5833359..415ad59 100644
--- a/deps.edn
+++ b/deps.edn
@@ -11,7 +11,9 @@
  {;; Application
   org.clojure/clojure {:mvn/version "1.11.4"}
   org.clojure/spec.alpha {:mvn/version "0.5.238"}
-  orchestra/orchestra {:mvn/version "2021.01.01-1"}}
+  orchestra/orchestra {:mvn/version "2021.01.01-1"}
+  cheshire/cheshire {:mvn/version "5.13.0"}
+  com.widdindustries/cljc.java-time {:mvn/version "0.1.21"}}
  ;; ---------------------------------------------------------
 
  ;; ---------------------------------------------------------
diff --git a/src/dda/backup/cred_rot/domain.clj b/src/dda/backup/cred_rot/domain.clj
index f05ce35..abe2e1b 100644
--- a/src/dda/backup/cred_rot/domain.clj
+++ b/src/dda/backup/cred_rot/domain.clj
@@ -1,11 +1,37 @@
 (ns dda.backup.cred-rot.domain
   (:require
    [orchestra.core :refer [defn-spec]]
-   [clojure.spec.alpha :as s]))
+   [clojure.spec.alpha :as s]
+   [clojure.string :as str]
+   [cljc.java-time.local-date :as ld]
+   [cljc.java-time.format.date-time-formatter :as df]))
 
 (s/def ::new-password-file string?)
 
-; Refer to "docs/CredentialRotation.md" for specifics 
+(def lowercase-numeric #"[a-z0-9]+")
+(def alphanumeric #"[a-zA-Z0-9]+")
+
+; true | false
+(s/def ::current boolean?)
+; 521e0760
+(s/def ::id (s/and string? #(re-matches lowercase-numeric %)))
+; root
+(s/def ::userName #(re-matches alphanumeric %))
+; backup-restore-65bd9b6ff5-z69sn
+(s/def ::hostName (fn [in] (every? #(re-matches lowercase-numeric %) (str/split in #"-"))))
+; "2024-10-18 13:08:16"
+(def timestamp-formatter (df/of-pattern "yyyy-MM-dd HH:mm:ss"))
+(s/def ::created #(try
+                    (ld/parse % timestamp-formatter)
+                    true 
+                    (catch Exception _ false)))
+
+(s/def ::entry (s/keys :opt-un []
+                       :req-un [::current ::id ::userName ::hostName ::created]))
+(s/def ::response (s/coll-of ::entry))
+
+
+; Refer to "docs/CredentialRotation.md" for specifics
 
 (defn-spec add-new-password! nil?
   [new-password-file ::new-password-file]
diff --git a/test/dda/backup/cred_rot/domain_test.clj b/test/dda/backup/cred_rot/domain_test.clj
new file mode 100644
index 0000000..95042bc
--- /dev/null
+++ b/test/dda/backup/cred_rot/domain_test.clj
@@ -0,0 +1,33 @@
+(ns dda.backup.cred-rot.domain-test
+  (:require
+   [clojure.test :refer [deftest is]]
+   [clojure.spec.alpha :as s]
+   [clojure.spec.test.alpha :as st]
+   [dda.backup.cred-rot.domain :as cut]))
+
+(deftest test-spec-id
+  (is (s/valid? ::cut/id "521e0760"))
+  (is (s/valid? ::cut/id "test"))
+  (is (s/valid? ::cut/id "123456"))
+  (is (not (s/valid? ::cut/id "ROOT")))
+  (is (not (s/valid? ::cut/id "Test!"))))
+
+(deftest test-spec-username
+  (is (s/valid? ::cut/userName "521e0760"))
+  (is (s/valid? ::cut/userName "Testuser"))
+  (is (s/valid? ::cut/userName "root"))
+  (is (s/valid? ::cut/userName "ROOT"))
+  (is (not (s/valid? ::cut/userName "test-user"))))
+
+(deftest test-spec-hostName
+  (let [valid #(s/valid? ::cut/hostName %)]
+    (is (valid "test-some-combination-2"))
+    (is (valid "backup-restore-65bd9b6ff5-z69sn"))))
+
+(deftest test-spec-created
+  (let [valid #(s/valid? ::cut/created %)]
+    (is (valid "2024-10-18 13:08:16"))
+    (is (valid "2032-09-01 12:56:59"))
+    (is (not (valid "2024-13-5 13:08:16")))
+    (is (not (valid "2024-6-42 13:08:16")))
+    (is (not (valid "test")))))
\ No newline at end of file