++

src/guard/Cargo.toml

@@ -8,3 +8,4 @@ ic-cdk = "0.15.0"
 ic-papi-api = { workspace = true }
 candid = { workspace = true }
 cycles-ledger-client = { workspace = true }
+serde_bytes = { workspace = true }

src/guard/src/guards/icrc2_cycles.rs

@@ -5,26 +5,49 @@ use ic_papi_api::{Account, Icrc2Payer};
 
 pub struct Icrc2CyclesPaymentGuard {
     /// The payer
-    pub payer: Icrc2Payer,
+    pub payer_account: Account,
+    /// The spender, if different from the payer.
+    pub spender_subaccount: Option<serde_bytes::ByteBuf>,
+    /// The ICRC-2 time, if applicable.
+    pub created_at_time: Option<u64>,
     /// The ledger to withdraw the cycles from.
     pub ledger_canister_id: Principal,
     /// Own canister ID
     pub own_canister_id: Principal,
 }
+impl Icrc2CyclesPaymentGuard {
+    pub fn default_account() -> Account {
+        Account {
+            owner: ic_cdk::caller(),
+            subaccount: None,
+        }
+    }
+    pub fn default_cycles_ledger() -> Principal {
+        Principal::from_text(
+            option_env!("DFX_CYCLES_LEDGER_CANISTER_ID").unwrap_or("um5iw-rqaaa-aaaaq-qaaba-cai"),
+        )
+        .expect("Failed to parse cycles ledger canister ID")
+    }
+    pub fn new(own_canister_id: Principal) -> Self {
+        Self {
+            payer_account: Self::default_account(),
+            ledger_canister_id: Self::default_cycles_ledger(),
+            own_canister_id,
+            created_at_time: None,
+            spender_subaccount: None,
+        }
+    }
+}
 
 impl PaymentGuard for Icrc2CyclesPaymentGuard {
     async fn deduct(&self, fee: u64) -> Result<(), PaymentError> {
-        let account = self.payer.account.clone().unwrap_or_else(|| Account {
-            owner: ic_cdk::caller(),
-            subaccount: None,
-        });
         cycles_ledger_client::Service(self.ledger_canister_id)
             .withdraw_from(&WithdrawFromArgs {
                 to: self.own_canister_id.clone(),
                 amount: Nat::from(fee),
-                from: account,
-                spender_subaccount: self.payer.spender_subaccount.clone(),
-                created_at_time: self.payer.created_at_time,
+                from: self.payer_account.clone(),
+                spender_subaccount: self.spender_subaccount.clone(),
+                created_at_time: self.created_at_time,
             })
             .await
             .map_err(|(rejection_code, string)| {