diff --git a/src/lib.rs b/src/lib.rs
index 50bc1b5..bed7751 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -4,3 +4,9 @@ pub mod envy;
 pub mod message;
 pub mod token;
 pub mod user;
+
+pub mod init {
+    pub fn is_uuid_nil(uuid: &uuid::Uuid) -> bool {
+        uuid.is_nil()
+    }
+}
diff --git a/src/user/mod.rs b/src/user/mod.rs
index 9f883d6..fc72f0f 100644
--- a/src/user/mod.rs
+++ b/src/user/mod.rs
@@ -14,6 +14,8 @@ pub struct User {
     pub created: Option<time::OffsetDateTime>,
     #[serde(with = "time::serde::rfc3339::option")]
     pub last_login: Option<time::OffsetDateTime>,
+    #[serde(skip)]
+    pub salt_id: uuid::Uuid,
 }
 
 #[derive(Clone, Debug, Default, Deserialize, Serialize)]
@@ -26,6 +28,8 @@ pub struct ServiceUser {
     // When serializing to json, if empty do not populate
     #[serde(with = "time::serde::rfc3339::option")]
     pub last_login: Option<time::OffsetDateTime>,
+    #[serde(skip)]
+    pub salt_id: uuid::Uuid,
 }
 
 #[derive(Clone, Debug, Default, Deserialize, Serialize)]
@@ -65,6 +69,24 @@ pub struct UserProfile {
     pub last_login: Option<time::OffsetDateTime>,
 }
 
+#[derive(Clone, Debug, Default, Deserialize, Serialize)]
+pub struct Salt {
+    #[serde(skip_serializing_if = "crate::init::is_uuid_nil")]
+    pub id: uuid::Uuid,
+    #[serde(skip_serializing_if = "String::is_empty")]
+    pub salt: String,
+}
+
+impl Salt {
+    pub fn to_json(&self, output_pretty: bool) -> Result<String, serde_json::Error> {
+        if output_pretty {
+            serde_json::to_string_pretty(&self)
+        } else {
+            serde_json::to_string(&self)
+        }
+    }
+}
+
 pub fn init_user_profile(usr: &User) -> UserProfile {
     UserProfile {
         user_id: usr.id,