diff --git a/contracts/guardian/src/lib.rs b/contracts/guardian/src/lib.rs
index 0efa0cc..e7969d1 100644
--- a/contracts/guardian/src/lib.rs
+++ b/contracts/guardian/src/lib.rs
@@ -1,5 +1,6 @@
 #![no_std]
 pub mod error;
+pub mod types;
 use soroban_sdk::{contract, contractimpl, Env};
 
 /// Enforces guardian-controlled spending policies for child wallet accounts on the Stellar network.
diff --git a/contracts/guardian/src/types.rs b/contracts/guardian/src/types.rs
new file mode 100644
index 0000000..6ec8ae4
--- /dev/null
+++ b/contracts/guardian/src/types.rs
@@ -0,0 +1,25 @@
+use soroban_sdk::{contracttype, Address};
+
+/// Opaque identifier for a child wallet account managed by a guardian.
+pub type ChildId = Address;
+
+/// Maximum amount (in stroops) a child may spend in a single transaction.
+pub type SpendLimit = u64;
+
+/// Period over which the spend limit resets.
+#[contracttype]
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub enum LimitPeriod {
+    Daily,
+    Weekly,
+    Monthly,
+}
+
+/// Full spending policy attached to a child account.
+#[contracttype]
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct SpendPolicy {
+    pub child: ChildId,
+    pub limit: SpendLimit,
+    pub period: LimitPeriod,
+}