diff --git a/common/src/lib.rs b/common/src/lib.rs
index 92a5077..77acddf 100644
--- a/common/src/lib.rs
+++ b/common/src/lib.rs
@@ -1,9 +1,35 @@
 #![no_std]
-use soroban_sdk::contracterror;
+use soroban_sdk::{contracttype, contracterror};
+
+#[contracttype]
+#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+pub enum CampaignStatus {
+    Draft,
+    Active,
+    Completed,
+    Cancelled,
+}
+
+#[contracttype]
+#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+pub enum MilestoneStatus {
+    Pending,
+    Completed,
+    Failed,
+}
+
+#[contracttype]
+#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+pub struct AssetInfo {
+    pub code: u32,
+    pub issuer: u32,
+}
 
 #[contracterror]
 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
-pub enum Error {
+pub enum ErrorCode {
     NotInitialized = 1,
     AlreadyInitialized = 2,
+    Unauthorized = 3,
+    InvalidAmount = 4,
 }