vault_factory: add list_recent_vaults(limit)

soroban-contracts/contracts/vault_factory/src/lib.rs

@@ -31,6 +31,10 @@ const MAX_BATCH_SIZE: u32 = 10;
 /// Maximum page size for status-filtered vault list queries.
 const MAX_STATUS_PAGE_SIZE: u32 = 50;
 
+/// Maximum number of entries to scan when building the recent list.
+/// Bounds runtime even if many historic vaults have been removed.
+const MAX_RECENT_SCAN: u32 = 200;
+
 // ─────────────────────────────────────────────────────────────────────────────
 // Contract
 // ─────────────────────────────────────────────────────────────────────────────
@@ -468,6 +472,40 @@ impl VaultFactory {
         result
     }
 
+    /// Returns the most recently created vaults (newest-first).
+    ///
+    /// Deterministic ordering is based on the factory's monotonic deploy counter,
+    /// not the live registry index (which uses swap-remove on deletion).
+    ///
+    /// `limit` is capped to 50. Returns an empty vec when `limit == 0` or when
+    /// no vaults exist. Removed vaults are skipped.
+    pub fn list_recent_vaults(e: &Env, limit: u32) -> Vec<Address> {
+        let capped = limit.min(MAX_STATUS_PAGE_SIZE);
+        let mut result: Vec<Address> = Vec::new(e);
+        if capped == 0 {
+            return result;
+        }
+
+        let mut deploy_id = get_vault_deploy_counter(e);
+        if deploy_id == 0 {
+            return result;
+        }
+
+        let mut scanned: u32 = 0;
+        while deploy_id > 0 && result.len() < capped && scanned < MAX_RECENT_SCAN {
+            if let Some(vault) = get_vault_by_deploy_id(e, deploy_id) {
+                // Skip removed/unregistered vaults.
+                if get_vault_info(e, &vault).is_some() {
+                    result.push_back(vault);
+                }
+            }
+            deploy_id -= 1;
+            scanned += 1;
+        }
+
+        result
+    }
+
     /// Returns a page of *active* vault addresses.
     ///
     /// `offset` is zero-based within the active-vault list. Returns an empty
@@ -896,6 +934,8 @@ impl VaultFactory {
         };
         put_vault_info(e, &vault_addr, info);
         register_vault(e, vault_addr.clone());
+        // Persist deploy ordering for recent-vault queries.
+        put_vault_by_deploy_id(e, counter, &vault_addr);
         push_vaults_by_asset(e, &vault_asset, vault_addr.clone());
 
         emit_vault_created(

soroban-contracts/contracts/vault_factory/src/storage.rs

@@ -40,6 +40,11 @@ pub enum DataKey {
     VaultInfo(Address),
     VaultCount,
     VaultDeployCounter,
+    /// Monotonic deploy id → vault address mapping (persistent).
+    ///
+    /// This preserves deterministic "most recent vaults" ordering even when
+    /// vaults are removed from the indexed registry (which uses swap-remove).
+    VaultByDeployId(u32),
     VaultsByAsset(Address),
     DefaultFeeBps,
 }
@@ -268,6 +273,16 @@ pub fn increment_vault_deploy_counter(e: &Env) -> u32 {
     count
 }
 
+pub fn get_vault_by_deploy_id(e: &Env, id: u32) -> Option<Address> {
+    e.storage().persistent().get(&DataKey::VaultByDeployId(id))
+}
+
+pub fn put_vault_by_deploy_id(e: &Env, id: u32, vault: &Address) {
+    let key = DataKey::VaultByDeployId(id);
+    e.storage().persistent().set(&key, vault);
+    bump_persist(e, &key);
+}
+
 // ─────────────────────────────────────────────────────────────────────────────
 // VaultInfo (Persistent, keyed by vault address)
 // ─────────────────────────────────────────────────────────────────────────────

soroban-contracts/contracts/vault_factory/src/tests.rs

@@ -6,7 +6,10 @@ use soroban_sdk::{
 };
 
 use crate::{
-    storage::{get_vault_count, get_vault_info, put_vault_info, register_vault},
+    storage::{
+        get_vault_count, get_vault_info, increment_vault_deploy_counter, put_vault_by_deploy_id,
+        put_vault_info, register_vault,
+    },
     types::{VaultInfo, VaultType},
     VaultFactory, VaultFactoryClient,
 };
@@ -122,6 +125,15 @@ fn inject_vault(e: &Env, factory_id: &Address, active: bool) -> Address {
     vault
 }
 
+fn inject_vault_with_deploy_id(e: &Env, factory_id: &Address, active: bool) -> Address {
+    let vault = inject_vault(e, factory_id, active);
+    e.as_contract(factory_id, || {
+        let id = increment_vault_deploy_counter(e);
+        put_vault_by_deploy_id(e, id, &vault);
+    });
+    vault
+}
+
 /// `VaultInfo.asset` is stored in the registry and returned by `get_vault_info` so
 /// indexers can resolve the underlying asset without N+1 vault calls.
 #[test]
@@ -1110,3 +1122,32 @@ fn test_get_all_vaults_returns_vaults_in_creation_order() {
     // Verify vault count matches
     assert_eq!(client.get_vault_count(), 4);
 }
+
+#[test]
+fn test_list_recent_vaults_returns_newest_first() {
+    let e = Env::default();
+    e.mock_all_auths();
+    let (factory_id, _admin) = setup_factory(&e);
+    let client = VaultFactoryClient::new(&e, &factory_id);
+
+    let v1 = inject_vault_with_deploy_id(&e, &factory_id, true);
+    let v2 = inject_vault_with_deploy_id(&e, &factory_id, true);
+    let v3 = inject_vault_with_deploy_id(&e, &factory_id, true);
+    let v4 = inject_vault_with_deploy_id(&e, &factory_id, true);
+    let v5 = inject_vault_with_deploy_id(&e, &factory_id, true);
+
+    let recent = client.list_recent_vaults(&3);
+    assert_eq!(recent.len(), 3);
+    assert_eq!(recent.get(0).unwrap(), v5);
+    assert_eq!(recent.get(1).unwrap(), v4);
+    assert_eq!(recent.get(2).unwrap(), v3);
+
+    // Asking for more than exist returns all (up to cap).
+    let all_recent = client.list_recent_vaults(&10);
+    assert_eq!(all_recent.len(), 5);
+    assert_eq!(all_recent.get(4).unwrap(), v1);
+    assert_eq!(all_recent.get(0).unwrap(), v5);
+    assert_eq!(all_recent.get(1).unwrap(), v4);
+    assert_eq!(all_recent.get(2).unwrap(), v3);
+    assert_eq!(all_recent.get(3).unwrap(), v2);
+}