fix: add [[nodiscard]] to preclaim helpers and cover pre-amendment path

Mark readVault, preclaimUpdate, and preclaimCreate with [[nodiscard]]
to match project convention for error-bearing return types. Add test
for the pre-amendment preclaimUpdate path where the vault doesn't
exist (readVault returning tecNO_ENTRY).

include/xrpl/protocol/STAmount.h

@@ -42,8 +42,8 @@ private:
 public:
     using value_type = STAmount;
 
-    static int const cMinOffset = -96;
-    static int const cMaxOffset = 80;
+    static int constexpr cMinOffset = -96;
+    static int constexpr cMaxOffset = 80;
 
     // Maximum native value supported by the code
     constexpr static std::uint64_t cMinValue = 1'000'000'000'000'000ull;
@@ -739,6 +739,21 @@ canAdd(STAmount const& amt1, STAmount const& amt2);
 bool
 canSubtract(STAmount const& amt1, STAmount const& amt2);
 
+/** Get the scale of a Number for a given asset.
+ *
+ * "scale" is similar to "exponent", but from the perspective of STAmount, which has different rules
+ * and mantissa ranges for determining the exponent than Number.
+ *
+ * @param number The Number to get the scale of.
+ * @param asset The asset to use for determining the scale.
+ * @return The scale of this Number for the given asset.
+ */
+inline int
+scale(Number const& number, Asset const& asset)
+{
+    return STAmount{asset, number}.exponent();
+}
+
 }  // namespace xrpl
 
 //------------------------------------------------------------------------------

include/xrpl/protocol/detail/features.macro

@@ -17,6 +17,7 @@
 // Keep it sorted in reverse chronological order.
 
 XRPL_FIX   (Security3_1_3,               Supported::no, VoteBehavior::DefaultNo)
+XRPL_FEATURE(LendingProtocolV1_1,        Supported::yes, VoteBehavior::DefaultNo)
 XRPL_FIX   (PermissionedDomainInvariant, Supported::yes, VoteBehavior::DefaultNo)
 XRPL_FIX    (ExpiredNFTokenOfferRemoval, Supported::yes, VoteBehavior::DefaultNo)
 XRPL_FIX    (BatchInnerSigs,             Supported::no, VoteBehavior::DefaultNo)

include/xrpl/protocol/detail/transactions.macro

@@ -886,6 +886,7 @@ TRANSACTION(ttVAULT_DELETE, 67, VaultDelete,
     mustDeleteAcct | destroyMPTIssuance | mustModifyVault,
     ({
     {sfVaultID, soeREQUIRED},
+    {sfMemoData, soeOPTIONAL},
 }))
 
 /** This transaction trades assets for shares with a vault. */
@@ -953,7 +954,7 @@ TRANSACTION(ttLOAN_BROKER_SET, 74, LoanBrokerSet,
     Delegation::notDelegable,
     featureLendingProtocol,
     createPseudoAcct | mayAuthorizeMPT, ({
-    {sfVaultID, soeREQUIRED},
+    {sfVaultID, soeOPTIONAL},
     {sfLoanBrokerID, soeOPTIONAL},
     {sfData, soeOPTIONAL},
     {sfManagementFeeRate, soeOPTIONAL},

include/xrpl/protocol_autogen/transactions/LoanBrokerSet.h

@@ -48,14 +48,29 @@ public:
     // Transaction-specific field getters
 
     /**
-     * @brief Get sfVaultID (soeREQUIRED)
-     * @return The field value.
+     * @brief Get sfVaultID (soeOPTIONAL)
+     * @return The field value, or std::nullopt if not present.
      */
     [[nodiscard]]
-    SF_UINT256::type::value_type
+    protocol_autogen::Optional<SF_UINT256::type::value_type>
     getVaultID() const
     {
-        return this->tx_->at(sfVaultID);
+        if (hasVaultID())
+        {
+            return this->tx_->at(sfVaultID);
+        }
+        return std::nullopt;
+    }
+
+    /**
+     * @brief Check if sfVaultID is present.
+     * @return True if the field is present, false otherwise.
+     */
+    [[nodiscard]]
+    bool
+    hasVaultID() const
+    {
+        return this->tx_->isFieldPresent(sfVaultID);
     }
 
     /**
@@ -228,17 +243,15 @@ public:
     /**
      * @brief Construct a new LoanBrokerSetBuilder with required fields.
      * @param account The account initiating the transaction.
-     * @param vaultID The sfVaultID field value.
      * @param sequence Optional sequence number for the transaction.
      * @param fee Optional fee for the transaction.
      */
     LoanBrokerSetBuilder(SF_ACCOUNT::type::value_type account,
-                     std::decay_t<typename SF_UINT256::type::value_type> const& vaultID,                    std::optional<SF_UINT32::type::value_type> sequence = std::nullopt,
+                    std::optional<SF_UINT32::type::value_type> sequence = std::nullopt,
                     std::optional<SF_AMOUNT::type::value_type> fee = std::nullopt
 )
         : TransactionBuilderBase<LoanBrokerSetBuilder>(ttLOAN_BROKER_SET, account, sequence, fee)
     {
-        setVaultID(vaultID);
     }
 
     /**
@@ -258,7 +271,7 @@ public:
     /** @brief Transaction-specific field setters */
 
     /**
-     * @brief Set sfVaultID (soeREQUIRED)
+     * @brief Set sfVaultID (soeOPTIONAL)
      * @return Reference to this builder for method chaining.
      */
     LoanBrokerSetBuilder&

include/xrpl/protocol_autogen/transactions/VaultDelete.h

@@ -57,6 +57,32 @@ public:
     {
         return this->tx_->at(sfVaultID);
     }
+
+    /**
+     * @brief Get sfMemoData (soeOPTIONAL)
+     * @return The field value, or std::nullopt if not present.
+     */
+    [[nodiscard]]
+    protocol_autogen::Optional<SF_VL::type::value_type>
+    getMemoData() const
+    {
+        if (hasMemoData())
+        {
+            return this->tx_->at(sfMemoData);
+        }
+        return std::nullopt;
+    }
+
+    /**
+     * @brief Check if sfMemoData is present.
+     * @return True if the field is present, false otherwise.
+     */
+    [[nodiscard]]
+    bool
+    hasMemoData() const
+    {
+        return this->tx_->isFieldPresent(sfMemoData);
+    }
 };
 
 /**
@@ -112,6 +138,17 @@ public:
         return *this;
     }
 
+    /**
+     * @brief Set sfMemoData (soeOPTIONAL)
+     * @return Reference to this builder for method chaining.
+     */
+    VaultDeleteBuilder&
+    setMemoData(std::decay_t<typename SF_VL::type::value_type> const& value)
+    {
+        object_[sfMemoData] = value;
+        return *this;
+    }
+
     /**
      * @brief Build and return the VaultDelete wrapper.
      * @param publicKey The public key for signing.

include/xrpl/tx/invariants/VaultInvariant.h

@@ -8,6 +8,7 @@
 #include <xrpl/protocol/STTx.h>
 #include <xrpl/protocol/TER.h>
 
+#include <optional>
 #include <unordered_map>
 #include <vector>
 
@@ -60,11 +61,19 @@ class ValidVault
         Shares static make(SLE const&);
     };
 
+public:
+    struct DeltaInfo final
+    {
+        Number delta = numZero;
+        std::optional<int> scale;
+    };
+
+private:
     std::vector<Vault> afterVault_ = {};
     std::vector<Shares> afterMPTs_ = {};
     std::vector<Vault> beforeVault_ = {};
     std::vector<Shares> beforeMPTs_ = {};
-    std::unordered_map<uint256, Number> deltas_ = {};
+    std::unordered_map<uint256, DeltaInfo> deltas_ = {};
 
 public:
     void
@@ -72,6 +81,10 @@ public:
 
     bool
     finalize(STTx const&, TER const, XRPAmount const, ReadView const&, beast::Journal const&);
+
+    // Compute the coarsest scale required to represent all numbers
+    [[nodiscard]] static std::int32_t
+    computeMinScale(Asset const& asset, std::vector<DeltaInfo> const& numbers);
 };
 
 }  // namespace xrpl

include/xrpl/tx/transactors/lending/LendingHelpers.h

@@ -171,7 +171,7 @@ getAssetsTotalScale(SLE::const_ref vaultSle)
 {
     if (!vaultSle)
         return Number::minExponent - 1;  // LCOV_EXCL_LINE
-    return STAmount{vaultSle->at(sfAsset), vaultSle->at(sfAssetsTotal)}.exponent();
+    return scale(vaultSle->at(sfAssetsTotal), vaultSle->at(sfAsset));
 }
 
 TER

src/libxrpl/tx/invariants/VaultInvariant.cpp

@@ -9,6 +9,7 @@
 #include <xrpl/protocol/LedgerFormats.h>
 #include <xrpl/protocol/Protocol.h>
 #include <xrpl/protocol/SField.h>
+#include <xrpl/protocol/STAmount.h>
 #include <xrpl/protocol/STNumber.h>
 #include <xrpl/protocol/TxFormats.h>
 #include <xrpl/tx/invariants/InvariantCheckPrivilege.h>
@@ -61,10 +62,12 @@ ValidVault::visitEntry(
         "xrpl::ValidVault::visitEntry : some object is available");
 
     // Number balanceDelta will capture the difference (delta) between "before"
-    // state (zero if created) and "after" state (zero if destroyed), so the
-    // invariants can validate that the change in account balances matches the
-    // change in vault balances, stored to deltas_ at the end of this function.
-    Number balanceDelta{};
+    // state (zero if created) and "after" state (zero if destroyed), and
+    // preserves value scale (exponent) to round values to the same scale during
+    // validation. It is used to validate that the change in account
+    // balances matches the change in vault balances, stored to deltas_ at the
+    // end of this function.
+    DeltaInfo balanceDelta{numZero, std::nullopt};
 
     std::int8_t sign = 0;
     if (before)
@@ -78,18 +81,34 @@ ValidVault::visitEntry(
                 // At this moment we have no way of telling if this object holds
                 // vault shares or something else. Save it for finalize.
                 beforeMPTs_.push_back(Shares::make(*before));
-                balanceDelta = static_cast<std::int64_t>(before->getFieldU64(sfOutstandingAmount));
+                balanceDelta.delta =
+                    static_cast<std::int64_t>(before->getFieldU64(sfOutstandingAmount));
+                // MPTs are ints, so the scale is always 0.
+                balanceDelta.scale = 0;
                 sign = 1;
                 break;
             case ltMPTOKEN:
-                balanceDelta = static_cast<std::int64_t>(before->getFieldU64(sfMPTAmount));
+                balanceDelta.delta = static_cast<std::int64_t>(before->getFieldU64(sfMPTAmount));
+                // MPTs are ints, so the scale is always 0.
+                balanceDelta.scale = 0;
                 sign = -1;
                 break;
             case ltACCOUNT_ROOT:
-            case ltRIPPLE_STATE:
-                balanceDelta = before->getFieldAmount(sfBalance);
+                balanceDelta.delta = before->getFieldAmount(sfBalance);
+                // Account balance is XRP, which is an int, so the scale is
+                // always 0.
+                balanceDelta.scale = 0;
                 sign = -1;
                 break;
+            case ltRIPPLE_STATE: {
+                auto const amount = before->getFieldAmount(sfBalance);
+                balanceDelta.delta = amount;
+                // Trust Line balances are STAmounts, so we can use the exponent
+                // directly to get the scale.
+                balanceDelta.scale = amount.exponent();
+                sign = -1;
+                break;
+            }
             default:;
         }
     }
@@ -105,19 +124,36 @@ ValidVault::visitEntry(
                 // At this moment we have no way of telling if this object holds
                 // vault shares or something else. Save it for finalize.
                 afterMPTs_.push_back(Shares::make(*after));
-                balanceDelta -=
+                balanceDelta.delta -=
                     Number(static_cast<std::int64_t>(after->getFieldU64(sfOutstandingAmount)));
+                // MPTs are ints, so the scale is always 0.
+                balanceDelta.scale = 0;
                 sign = 1;
                 break;
             case ltMPTOKEN:
-                balanceDelta -= Number(static_cast<std::int64_t>(after->getFieldU64(sfMPTAmount)));
+                balanceDelta.delta -=
+                    Number(static_cast<std::int64_t>(after->getFieldU64(sfMPTAmount)));
+                // MPTs are ints, so the scale is always 0.
+                balanceDelta.scale = 0;
                 sign = -1;
                 break;
             case ltACCOUNT_ROOT:
-            case ltRIPPLE_STATE:
-                balanceDelta -= Number(after->getFieldAmount(sfBalance));
+                balanceDelta.delta -= Number(after->getFieldAmount(sfBalance));
+                // Account balance is XRP, which is an int, so the scale is
+                // always 0.
+                balanceDelta.scale = 0;
                 sign = -1;
                 break;
+            case ltRIPPLE_STATE: {
+                auto const amount = after->getFieldAmount(sfBalance);
+                balanceDelta.delta -= Number(amount);
+                // Trust Line balances are STAmounts, so we can use the exponent
+                // directly to get the scale.
+                if (amount.exponent() > balanceDelta.scale)
+                    balanceDelta.scale = amount.exponent();
+                sign = -1;
+                break;
+            }
             default:;
         }
     }
@@ -129,7 +165,11 @@ ValidVault::visitEntry(
     // transferred to the account. We intentionally do not compare balanceDelta
     // against zero, to avoid missing such updates.
     if (sign != 0)
-        deltas_[key] = balanceDelta * sign;
+    {
+        XRPL_ASSERT_PARTS(balanceDelta.scale, "xrpl::ValidVault::visitEntry", "scale initialized");
+        balanceDelta.delta *= sign;
+        deltas_[key] = balanceDelta;
+    }
 }
 
 bool
@@ -391,13 +431,13 @@ ValidVault::finalize(
     }
 
     auto const& vaultAsset = afterVault.asset;
-    auto const deltaAssets = [&](AccountID const& id) -> std::optional<Number> {
+    auto const deltaAssets = [&](AccountID const& id) -> std::optional<DeltaInfo> {
         auto const get =  //
-            [&](auto const& it, std::int8_t sign = 1) -> std::optional<Number> {
+            [&](auto const& it, std::int8_t sign = 1) -> std::optional<DeltaInfo> {
             if (it == deltas_.end())
                 return std::nullopt;
 
-            return it->second * sign;
+            return DeltaInfo{it->second.delta * sign, it->second.scale};
         };
 
         return std::visit(
@@ -416,7 +456,7 @@ ValidVault::finalize(
             },
             vaultAsset.value());
     };
-    auto const deltaAssetsTxAccount = [&]() -> std::optional<Number> {
+    auto const deltaAssetsTxAccount = [&]() -> std::optional<DeltaInfo> {
         auto ret = deltaAssets(tx[sfAccount]);
         // Nothing returned or not XRP transaction
         if (!ret.has_value() || !vaultAsset.native())
@@ -427,20 +467,20 @@ ValidVault::finalize(
             delegate.has_value() && *delegate != tx[sfAccount])
             return ret;
 
-        *ret += fee.drops();
-        if (*ret == zero)
+        ret->delta += fee.drops();
+        if (ret->delta == zero)
             return std::nullopt;
 
         return ret;
     };
-    auto const deltaShares = [&](AccountID const& id) -> std::optional<Number> {
+    auto const deltaShares = [&](AccountID const& id) -> std::optional<DeltaInfo> {
         auto const it = [&]() {
             if (id == afterVault.pseudoId)
                 return deltas_.find(keylet::mptIssuance(afterVault.shareMPTID).key);
             return deltas_.find(keylet::mptoken(afterVault.shareMPTID, id).key);
         }();
 
-        return it != deltas_.end() ? std::optional<Number>(it->second) : std::nullopt;
+        return it != deltas_.end() ? std::optional<DeltaInfo>(it->second) : std::nullopt;
     };
 
     auto const vaultHoldsNoAssets = [&](Vault const& vault) {
@@ -567,16 +607,38 @@ ValidVault::finalize(
                     !beforeVault_.empty(), "xrpl::ValidVault::finalize : deposit updated a vault");
                 auto const& beforeVault = beforeVault_[0];
 
-                auto const vaultDeltaAssets = deltaAssets(afterVault.pseudoId);
-
-                if (!vaultDeltaAssets)
+                auto const maybeVaultDeltaAssets = deltaAssets(afterVault.pseudoId);
+                if (!maybeVaultDeltaAssets)
                 {
                     JLOG(j.fatal()) <<  //
                         "Invariant failed: deposit must change vault balance";
                     return false;  // That's all we can do
                 }
 
-                if (*vaultDeltaAssets > tx[sfAmount])
+                // Get the coarsest scale to round calculations to
+                DeltaInfo totalDelta{
+                    afterVault.assetsTotal - beforeVault.assetsTotal,
+                    std::max(
+                        scale(afterVault.assetsTotal, vaultAsset),
+                        scale(beforeVault.assetsTotal, vaultAsset))};
+                DeltaInfo availableDelta{
+                    afterVault.assetsAvailable - beforeVault.assetsAvailable,
+                    std::max(
+                        scale(afterVault.assetsAvailable, vaultAsset),
+                        scale(beforeVault.assetsAvailable, vaultAsset))};
+                auto const minScale = computeMinScale(
+                    vaultAsset,
+                    {
+                        *maybeVaultDeltaAssets,
+                        totalDelta,
+                        availableDelta,
+                    });
+
+                auto const vaultDeltaAssets =
+                    roundToAsset(vaultAsset, maybeVaultDeltaAssets->delta, minScale);
+                auto const txAmount = roundToAsset(vaultAsset, tx[sfAmount], minScale);
+
+                if (vaultDeltaAssets > txAmount)
                 {
                     JLOG(j.fatal()) <<  //
                         "Invariant failed: deposit must not change vault "
@@ -584,7 +646,7 @@ ValidVault::finalize(
                     result = false;
                 }
 
-                if (*vaultDeltaAssets <= zero)
+                if (vaultDeltaAssets <= zero)
                 {
                     JLOG(j.fatal()) <<  //
                         "Invariant failed: deposit must increase vault balance";
@@ -601,16 +663,23 @@ ValidVault::finalize(
 
                 if (!issuerDeposit)
                 {
-                    auto const accountDeltaAssets = deltaAssetsTxAccount();
-                    if (!accountDeltaAssets)
+                    auto const maybeAccDeltaAssets = deltaAssetsTxAccount();
+                    if (!maybeAccDeltaAssets)
                     {
                         JLOG(j.fatal()) <<  //
                             "Invariant failed: deposit must change depositor "
                             "balance";
                         return false;
                     }
+                    auto const localMinScale =
+                        std::max(minScale, computeMinScale(vaultAsset, {*maybeAccDeltaAssets}));
 
-                    if (*accountDeltaAssets >= zero)
+                    auto const accountDeltaAssets =
+                        roundToAsset(vaultAsset, maybeAccDeltaAssets->delta, localMinScale);
+                    auto const localVaultDeltaAssets =
+                        roundToAsset(vaultAsset, vaultDeltaAssets, localMinScale);
+
+                    if (accountDeltaAssets >= zero)
                     {
                         JLOG(j.fatal()) <<  //
                             "Invariant failed: deposit must decrease depositor "
@@ -618,7 +687,7 @@ ValidVault::finalize(
                         result = false;
                     }
 
-                    if (*accountDeltaAssets * -1 != *vaultDeltaAssets)
+                    if (localVaultDeltaAssets * -1 != accountDeltaAssets)
                     {
                         JLOG(j.fatal()) <<  //
                             "Invariant failed: deposit must change vault and "
@@ -636,16 +705,17 @@ ValidVault::finalize(
                     result = false;
                 }
 
-                auto const accountDeltaShares = deltaShares(tx[sfAccount]);
-                if (!accountDeltaShares)
+                auto const maybeAccDeltaShares = deltaShares(tx[sfAccount]);
+                if (!maybeAccDeltaShares)
                 {
                     JLOG(j.fatal()) <<  //
                         "Invariant failed: deposit must change depositor "
                         "shares";
                     return false;  // That's all we can do
                 }
-
-                if (*accountDeltaShares <= zero)
+                // We don't need to round shares, they are integral MPT
+                auto const& accountDeltaShares = *maybeAccDeltaShares;
+                if (accountDeltaShares.delta <= zero)
                 {
                     JLOG(j.fatal()) <<  //
                         "Invariant failed: deposit must increase depositor "
@@ -653,15 +723,17 @@ ValidVault::finalize(
                     result = false;
                 }
 
-                auto const vaultDeltaShares = deltaShares(afterVault.pseudoId);
-                if (!vaultDeltaShares || *vaultDeltaShares == zero)
+                auto const maybeVaultDeltaShares = deltaShares(afterVault.pseudoId);
+                if (!maybeVaultDeltaShares || maybeVaultDeltaShares->delta == zero)
                 {
                     JLOG(j.fatal()) <<  //
                         "Invariant failed: deposit must change vault shares";
                     return false;  // That's all we can do
                 }
 
-                if (*vaultDeltaShares * -1 != *accountDeltaShares)
+                // We don't need to round shares, they are integral MPT
+                auto const& vaultDeltaShares = *maybeVaultDeltaShares;
+                if (vaultDeltaShares.delta * -1 != accountDeltaShares.delta)
                 {
                     JLOG(j.fatal()) <<  //
                         "Invariant failed: deposit must change depositor and "
@@ -669,13 +741,18 @@ ValidVault::finalize(
                     result = false;
                 }
 
-                if (beforeVault.assetsTotal + *vaultDeltaAssets != afterVault.assetsTotal)
+                auto const assetTotalDelta = roundToAsset(
+                    vaultAsset, afterVault.assetsTotal - beforeVault.assetsTotal, minScale);
+                if (assetTotalDelta != vaultDeltaAssets)
                 {
                     JLOG(j.fatal()) << "Invariant failed: deposit and assets "
                                        "outstanding must add up";
                     result = false;
                 }
-                if (beforeVault.assetsAvailable + *vaultDeltaAssets != afterVault.assetsAvailable)
+
+                auto const assetAvailableDelta = roundToAsset(
+                    vaultAsset, afterVault.assetsAvailable - beforeVault.assetsAvailable, minScale);
+                if (assetAvailableDelta != vaultDeltaAssets)
                 {
                     JLOG(j.fatal()) << "Invariant failed: deposit and assets "
                                        "available must add up";
@@ -693,16 +770,33 @@ ValidVault::finalize(
                     "vault");
                 auto const& beforeVault = beforeVault_[0];
 
-                auto const vaultDeltaAssets = deltaAssets(afterVault.pseudoId);
+                auto const maybeVaultDeltaAssets = deltaAssets(afterVault.pseudoId);
 
-                if (!vaultDeltaAssets)
+                if (!maybeVaultDeltaAssets)
                 {
                     JLOG(j.fatal()) << "Invariant failed: withdrawal must "
                                        "change vault balance";
                     return false;  // That's all we can do
                 }
 
-                if (*vaultDeltaAssets >= zero)
+                // Get the most coarse scale to round calculations to
+                auto const totalDelta = DeltaInfo{
+                    afterVault.assetsTotal - beforeVault.assetsTotal,
+                    std::max(
+                        scale(afterVault.assetsTotal, vaultAsset),
+                        scale(beforeVault.assetsTotal, vaultAsset))};
+                auto const availableDelta = DeltaInfo{
+                    afterVault.assetsAvailable - beforeVault.assetsAvailable,
+                    std::max(
+                        scale(afterVault.assetsAvailable, vaultAsset),
+                        scale(beforeVault.assetsAvailable, vaultAsset))};
+                auto const minScale = computeMinScale(
+                    vaultAsset, {*maybeVaultDeltaAssets, totalDelta, availableDelta});
+
+                auto const vaultPseudoDeltaAssets =
+                    roundToAsset(vaultAsset, maybeVaultDeltaAssets->delta, minScale);
+
+                if (vaultPseudoDeltaAssets >= zero)
                 {
                     JLOG(j.fatal()) << "Invariant failed: withdrawal must "
                                        "decrease vault balance";
@@ -720,15 +814,15 @@ ValidVault::finalize(
 
                 if (!issuerWithdrawal)
                 {
-                    auto const accountDeltaAssets = deltaAssetsTxAccount();
-                    auto const otherAccountDelta = [&]() -> std::optional<Number> {
+                    auto const maybeAccDelta = deltaAssetsTxAccount();
+                    auto const maybeOtherAccDelta = [&]() -> std::optional<DeltaInfo> {
                         if (auto const destination = tx[~sfDestination];
                             destination && *destination != tx[sfAccount])
                             return deltaAssets(*destination);
                         return std::nullopt;
                     }();
 
-                    if (accountDeltaAssets.has_value() == otherAccountDelta.has_value())
+                    if (maybeAccDelta.has_value() == maybeOtherAccDelta.has_value())
                     {
                         JLOG(j.fatal()) <<  //
                             "Invariant failed: withdrawal must change one "
@@ -737,9 +831,17 @@ ValidVault::finalize(
                     }
 
                     auto const destinationDelta =  //
-                        accountDeltaAssets ? *accountDeltaAssets : *otherAccountDelta;
+                        maybeAccDelta ? *maybeAccDelta : *maybeOtherAccDelta;
 
-                    if (destinationDelta <= zero)
+                    // the scale of destinationDelta can be coarser than
+                    // minScale, so we take that into account when rounding
+                    auto const localMinScale =
+                        std::max(minScale, computeMinScale(vaultAsset, {destinationDelta}));
+
+                    auto const roundedDestinationDelta =
+                        roundToAsset(vaultAsset, destinationDelta.delta, localMinScale);
+
+                    if (roundedDestinationDelta <= zero)
                     {
                         JLOG(j.fatal()) <<  //
                             "Invariant failed: withdrawal must increase "
@@ -747,7 +849,9 @@ ValidVault::finalize(
                         result = false;
                     }
 
-                    if (*vaultDeltaAssets * -1 != destinationDelta)
+                    auto const localPseudoDeltaAssets =
+                        roundToAsset(vaultAsset, vaultPseudoDeltaAssets, localMinScale);
+                    if (localPseudoDeltaAssets * -1 != roundedDestinationDelta)
                     {
                         JLOG(j.fatal()) <<  //
                             "Invariant failed: withdrawal must change vault "
@@ -756,6 +860,7 @@ ValidVault::finalize(
                     }
                 }
 
+                // We don't need to round shares, they are integral MPT
                 auto const accountDeltaShares = deltaShares(tx[sfAccount]);
                 if (!accountDeltaShares)
                 {
@@ -765,7 +870,7 @@ ValidVault::finalize(
                     return false;
                 }
 
-                if (*accountDeltaShares >= zero)
+                if (accountDeltaShares->delta >= zero)
                 {
                     JLOG(j.fatal()) <<  //
                         "Invariant failed: withdrawal must decrease depositor "
@@ -773,15 +878,16 @@ ValidVault::finalize(
                     result = false;
                 }
 
+                // We don't need to round shares, they are integral MPT
                 auto const vaultDeltaShares = deltaShares(afterVault.pseudoId);
-                if (!vaultDeltaShares || *vaultDeltaShares == zero)
+                if (!vaultDeltaShares || vaultDeltaShares->delta == zero)
                 {
                     JLOG(j.fatal()) <<  //
                         "Invariant failed: withdrawal must change vault shares";
                     return false;  // That's all we can do
                 }
 
-                if (*vaultDeltaShares * -1 != *accountDeltaShares)
+                if (vaultDeltaShares->delta * -1 != accountDeltaShares->delta)
                 {
                     JLOG(j.fatal()) <<  //
                         "Invariant failed: withdrawal must change depositor "
@@ -789,15 +895,20 @@ ValidVault::finalize(
                     result = false;
                 }
 
+                auto const assetTotalDelta = roundToAsset(
+                    vaultAsset, afterVault.assetsTotal - beforeVault.assetsTotal, minScale);
                 // Note, vaultBalance is negative (see check above)
-                if (beforeVault.assetsTotal + *vaultDeltaAssets != afterVault.assetsTotal)
+                if (assetTotalDelta != vaultPseudoDeltaAssets)
                 {
                     JLOG(j.fatal()) << "Invariant failed: withdrawal and "
                                        "assets outstanding must add up";
                     result = false;
                 }
 
-                if (beforeVault.assetsAvailable + *vaultDeltaAssets != afterVault.assetsAvailable)
+                auto const assetAvailableDelta = roundToAsset(
+                    vaultAsset, afterVault.assetsAvailable - beforeVault.assetsAvailable, minScale);
+
+                if (assetAvailableDelta != vaultPseudoDeltaAssets)
                 {
                     JLOG(j.fatal()) << "Invariant failed: withdrawal and "
                                        "assets available must add up";
@@ -828,10 +939,24 @@ ValidVault::finalize(
                     }
                 }
 
-                auto const vaultDeltaAssets = deltaAssets(afterVault.pseudoId);
-                if (vaultDeltaAssets)
+                auto const maybeVaultDeltaAssets = deltaAssets(afterVault.pseudoId);
+                if (maybeVaultDeltaAssets)
                 {
-                    if (*vaultDeltaAssets >= zero)
+                    auto const totalDelta = DeltaInfo{
+                        afterVault.assetsTotal - beforeVault.assetsTotal,
+                        std::max(
+                            scale(afterVault.assetsTotal, vaultAsset),
+                            scale(beforeVault.assetsTotal, vaultAsset))};
+                    auto const availableDelta = DeltaInfo{
+                        afterVault.assetsAvailable - beforeVault.assetsAvailable,
+                        std::max(
+                            scale(afterVault.assetsAvailable, vaultAsset),
+                            scale(beforeVault.assetsAvailable, vaultAsset))};
+                    auto const minScale = computeMinScale(
+                        vaultAsset, {*maybeVaultDeltaAssets, totalDelta, availableDelta});
+                    auto const vaultDeltaAssets =
+                        roundToAsset(vaultAsset, maybeVaultDeltaAssets->delta, minScale);
+                    if (vaultDeltaAssets >= zero)
                     {
                         JLOG(j.fatal()) <<  //
                             "Invariant failed: clawback must decrease vault "
@@ -839,7 +964,9 @@ ValidVault::finalize(
                         result = false;
                     }
 
-                    if (beforeVault.assetsTotal + *vaultDeltaAssets != afterVault.assetsTotal)
+                    auto const assetsTotalDelta = roundToAsset(
+                        vaultAsset, afterVault.assetsTotal - beforeVault.assetsTotal, minScale);
+                    if (assetsTotalDelta != vaultDeltaAssets)
                     {
                         JLOG(j.fatal()) <<  //
                             "Invariant failed: clawback and assets outstanding "
@@ -847,8 +974,11 @@ ValidVault::finalize(
                         result = false;
                     }
 
-                    if (beforeVault.assetsAvailable + *vaultDeltaAssets !=
-                        afterVault.assetsAvailable)
+                    auto const assetAvailableDelta = roundToAsset(
+                        vaultAsset,
+                        afterVault.assetsAvailable - beforeVault.assetsAvailable,
+                        minScale);
+                    if (assetAvailableDelta != vaultDeltaAssets)
                     {
                         JLOG(j.fatal()) <<  //
                             "Invariant failed: clawback and assets available "
@@ -863,15 +993,15 @@ ValidVault::finalize(
                     return false;  // That's all we can do
                 }
 
-                auto const accountDeltaShares = deltaShares(tx[sfHolder]);
-                if (!accountDeltaShares)
+                // We don't need to round shares, they are integral MPT
+                auto const maybeAccountDeltaShares = deltaShares(tx[sfHolder]);
+                if (!maybeAccountDeltaShares)
                 {
                     JLOG(j.fatal()) <<  //
                         "Invariant failed: clawback must change holder shares";
                     return false;  // That's all we can do
                 }
-
-                if (*accountDeltaShares >= zero)
+                if (maybeAccountDeltaShares->delta >= zero)
                 {
                     JLOG(j.fatal()) <<  //
                         "Invariant failed: clawback must decrease holder "
@@ -879,15 +1009,16 @@ ValidVault::finalize(
                     result = false;
                 }
 
+                // We don't need to round shares, they are integral MPT
                 auto const vaultDeltaShares = deltaShares(afterVault.pseudoId);
-                if (!vaultDeltaShares || *vaultDeltaShares == zero)
+                if (!vaultDeltaShares || vaultDeltaShares->delta == zero)
                 {
                     JLOG(j.fatal()) <<  //
                         "Invariant failed: clawback must change vault shares";
                     return false;  // That's all we can do
                 }
 
-                if (*vaultDeltaShares * -1 != *accountDeltaShares)
+                if (vaultDeltaShares->delta * -1 != maybeAccountDeltaShares->delta)
                 {
                     JLOG(j.fatal()) <<  //
                         "Invariant failed: clawback must change holder and "
@@ -924,4 +1055,19 @@ ValidVault::finalize(
     return true;
 }
 
+[[nodiscard]] std::int32_t
+ValidVault::computeMinScale(Asset const& asset, std::vector<DeltaInfo> const& numbers)
+{
+    if (numbers.size() == 0)
+        return 0;
+
+    auto const max =
+        std::max_element(numbers.begin(), numbers.end(), [](auto const& a, auto const& b) -> bool {
+            return a.scale < b.scale;
+        });
+    XRPL_ASSERT_PARTS(
+        max->scale, "xrpl::ValidVault::computeMinScale", "scale set for destinationDelta");
+    return max->scale.value_or(STAmount::cMaxOffset);
+}
+
 }  // namespace xrpl

src/libxrpl/tx/transactors/lending/LoanBrokerCoverWithdraw.cpp

@@ -123,7 +123,7 @@ LoanBrokerCoverWithdraw::preclaim(PreclaimContext const& ctx)
         return roundToAsset(
             vaultAsset,
             tenthBipsOfValue(currentDebtTotal, TenthBips32(sleBroker->at(sfCoverRateMinimum))),
-            currentDebtTotal.exponent());
+            scale(currentDebtTotal, vaultAsset));
     }();
     if (coverAvail < amount)
         return tecINSUFFICIENT_FUNDS;

src/libxrpl/tx/transactors/lending/LoanBrokerSet.cpp

@@ -2,6 +2,7 @@
 //
 #include <xrpl/ledger/helpers/AccountRootHelpers.h>
 #include <xrpl/ledger/helpers/TokenHelpers.h>
+#include <xrpl/protocol/Feature.h>
 #include <xrpl/protocol/STTakesAsset.h>
 #include <xrpl/tx/transactors/lending/LendingHelpers.h>
 
@@ -31,7 +32,9 @@ LoanBrokerSet::preflight(PreflightContext const& ctx)
     if (!validNumericRange(tx[~sfDebtMaximum], Number(maxMPTokenAmount), Number(0)))
         return temINVALID;
 
-    if (tx.isFieldPresent(sfLoanBrokerID))
+    auto const isLoanBrokerUpdate = tx.isFieldPresent(sfLoanBrokerID);
+
+    if (isLoanBrokerUpdate)
     {
         // Fixed fields can not be specified if we're modifying an existing
         // LoanBroker Object
@@ -43,9 +46,27 @@ LoanBrokerSet::preflight(PreflightContext const& ctx)
             return temINVALID;
     }
 
-    if (auto const vaultID = tx.at(~sfVaultID))
+    // Amendment-specific field presence rules
+    if (ctx.rules.enabled(featureLendingProtocolV1_1))
     {
-        if (*vaultID == beast::zero)
+        if (isLoanBrokerUpdate)
+        {
+            if (tx.isFieldPresent(sfVaultID))
+                return temINVALID;
+        }
+        else
+        {
+            if (!tx.isFieldPresent(sfVaultID) || tx[sfVaultID] == beast::zero)
+                return temINVALID;
+        }
+    }
+    else
+    {
+        // Pre-amendment: VaultID was soeREQUIRED, must always be present
+        if (!tx.isFieldPresent(sfVaultID))
+            return temINVALID;
+
+        if (tx[sfVaultID] == beast::zero)
             return temINVALID;
     }
 
@@ -70,77 +91,157 @@ LoanBrokerSet::getValueFields()
     return valueFields;
 }
 
-TER
-LoanBrokerSet::preclaim(PreclaimContext const& ctx)
+/** Read and validate a vault, checking existence and ownership.
+ *
+ * @param ctx The preclaim context.
+ * @param account The expected vault owner.
+ * @param id The vault ID to look up.
+ * @return The vault SLE on success, or a TER error.
+ */
+[[nodiscard]] static Expected<std::shared_ptr<SLE const>, TER>
+readVault(PreclaimContext const& ctx, AccountID const& account, uint256 const& id)
 {
-    auto const& tx = ctx.tx;
-
-    auto const account = tx[sfAccount];
-    auto const vaultID = tx[sfVaultID];
-
-    auto const sleVault = ctx.view.read(keylet::vault(vaultID));
-    if (!sleVault)
+    auto const sle = ctx.view.read(keylet::vault(id));
+    if (!sle)
     {
         JLOG(ctx.j.warn()) << "Vault does not exist.";
-        return tecNO_ENTRY;
+        return Unexpected(tecNO_ENTRY);
     }
-    Asset const asset = sleVault->at(sfAsset);
-
-    if (account != sleVault->at(sfOwner))
+    if (account != sle->at(sfOwner))
     {
         JLOG(ctx.j.warn()) << "Account is not the owner of the Vault.";
-        return tecNO_PERMISSION;
+        return Unexpected(tecNO_PERMISSION);
     }
+    return sle;
+}
 
-    if (auto const brokerID = tx[~sfLoanBrokerID])
+/** Preclaim validation for updating an existing LoanBroker.
+ *
+ * @param ctx The preclaim context.
+ * @param account The transaction submitter.
+ * @param brokerID The LoanBroker ID to update.
+ * @return The vault SLE on success, or a TER error.
+ */
+[[nodiscard]] static Expected<std::shared_ptr<SLE const>, TER>
+preclaimUpdate(PreclaimContext const& ctx, AccountID const& account, uint256 const& brokerID)
+{
+    auto const& tx = ctx.tx;
+    bool const fixEnabled = ctx.view.rules().enabled(featureLendingProtocolV1_1);
+
+    std::shared_ptr<SLE const> sleBroker;
+    std::shared_ptr<SLE const> sleVault;
+
+    if (fixEnabled)
     {
-        // Updating an existing Broker
-
-        auto const sleBroker = ctx.view.read(keylet::loanbroker(*brokerID));
+        // Post-amendment: VaultID is not in the tx, read it from broker
+        sleBroker = ctx.view.read(keylet::loanbroker(brokerID));
         if (!sleBroker)
         {
             JLOG(ctx.j.warn()) << "LoanBroker does not exist.";
-            return tecNO_ENTRY;
-        }
-        if (vaultID != sleBroker->at(sfVaultID))
-        {
-            JLOG(ctx.j.warn()) << "Can not change VaultID on an existing LoanBroker.";
-            return tecNO_PERMISSION;
-        }
-        if (account != sleBroker->at(sfOwner))
-        {
-            JLOG(ctx.j.warn()) << "Account is not the owner of the LoanBroker.";
-            return tecNO_PERMISSION;
+            return Unexpected(tecNO_ENTRY);
         }
 
-        if (auto const debtMax = tx[~sfDebtMaximum])
-        {
-            // Can't reduce the debt maximum below the current total debt
-            auto const currentDebtTotal = sleBroker->at(sfDebtTotal);
-            if (*debtMax != 0 && *debtMax < currentDebtTotal)
-            {
-                JLOG(ctx.j.warn()) << "Cannot reduce DebtMaximum below current DebtTotal.";
-                return tecLIMIT_EXCEEDED;
-            }
-        }
+        auto const vault = readVault(ctx, account, sleBroker->at(sfVaultID));
+        if (!vault)
+            return vault;
+        sleVault = *vault;
     }
     else
     {
-        if (auto const ter = canAddHolding(ctx.view, asset))
-            return ter;
+        XRPL_ASSERT(
+            tx.isFieldPresent(sfVaultID),
+            "xrpl::LoanBrokerSet::preclaimUpdate : VaultID is present in the transaction");
+        // Pre-amendment: vault is validated before broker to preserve
+        // the original error ordering for historical transaction replay.
+        auto const vault = readVault(ctx, account, tx[sfVaultID]);
+        if (!vault)
+            return vault;
+        sleVault = *vault;
 
-        if (auto const ter = checkFrozen(ctx.view, sleVault->at(sfAccount), sleVault->at(sfAsset)))
+        sleBroker = ctx.view.read(keylet::loanbroker(brokerID));
+        if (!sleBroker)
         {
-            JLOG(ctx.j.warn()) << "Vault pseudo-account is frozen.";
-            return ter;
+            JLOG(ctx.j.warn()) << "LoanBroker does not exist.";
+            return Unexpected(tecNO_ENTRY);
+        }
+        if (tx[sfVaultID] != sleBroker->at(sfVaultID))
+        {
+            JLOG(ctx.j.warn()) << "Can not change VaultID on an existing LoanBroker.";
+            return Unexpected(tecNO_PERMISSION);
         }
     }
 
+    XRPL_ASSERT(sleVault, "xrpl::LoanBrokerSet::preclaimUpdate : sleVault is initialized");
+
+    if (account != sleBroker->at(sfOwner))
+    {
+        JLOG(ctx.j.warn()) << "Account is not the owner of the LoanBroker.";
+        return Unexpected(tecNO_PERMISSION);
+    }
+
+    if (auto const debtMax = tx[~sfDebtMaximum])
+    {
+        auto const currentDebtTotal = sleBroker->at(sfDebtTotal);
+        if (*debtMax != 0 && *debtMax < currentDebtTotal)
+        {
+            JLOG(ctx.j.warn()) << "Cannot reduce DebtMaximum below current DebtTotal.";
+            return Unexpected(tecLIMIT_EXCEEDED);
+        }
+    }
+
+    return sleVault;
+}
+
+/** Preclaim validation for creating a new LoanBroker.
+ *
+ * @param ctx The preclaim context.
+ * @param account The transaction submitter (vault owner).
+ * @return The vault SLE on success, or a TER error.
+ */
+[[nodiscard]] static Expected<std::shared_ptr<SLE const>, TER>
+preclaimCreate(PreclaimContext const& ctx, AccountID const& account)
+{
+    XRPL_ASSERT(
+        ctx.tx.isFieldPresent(sfVaultID),
+        "xrpl::LoanBrokerSet::preclaimCreate : VaultID is present in the transaction");
+    auto const vault = readVault(ctx, account, ctx.tx[sfVaultID]);
+    if (!vault)
+        return vault;
+    auto const& sleVault = *vault;
+
+    Asset const asset = sleVault->at(sfAsset);
+    if (auto const ter = canAddHolding(ctx.view, asset))
+        return Unexpected(ter);
+
+    if (auto const ter = checkFrozen(ctx.view, sleVault->at(sfAccount), sleVault->at(sfAsset)))
+    {
+        JLOG(ctx.j.warn()) << "Vault pseudo-account is frozen.";
+        return Unexpected(ter);
+    }
+
+    return sleVault;
+}
+
+TER
+LoanBrokerSet::preclaim(PreclaimContext const& ctx)
+{
+    auto const account = ctx.tx[sfAccount];
+
+    auto const maybeVault = [&]() -> Expected<std::shared_ptr<SLE const>, TER> {
+        if (auto const brokerID = ctx.tx[~sfLoanBrokerID])
+            return preclaimUpdate(ctx, account, *brokerID);
+        return preclaimCreate(ctx, account);
+    }();
+
+    if (!maybeVault)
+        return maybeVault.error();
+
     // Check that relevant values can be represented as the vault asset
-    // type. This is mostly only relevant for integral (non-IOU) types
+    // type. This is mostly only relevant for integral (non-IOU) types.
+    Asset const asset = (*maybeVault)->at(sfAsset);
     for (auto const& field : getValueFields())
     {
-        if (auto const value = tx[field]; value && STAmount{asset, *value} != *value)
+        if (auto const value = ctx.tx[field]; value && STAmount{asset, *value} != *value)
         {
             JLOG(ctx.j.warn()) << field.f->getName() << " (" << *value
                                << ") can not be represented as a(n) " << to_string(asset) << ".";

src/libxrpl/tx/transactors/vault/VaultDelete.cpp

@@ -21,6 +21,13 @@ VaultDelete::preflight(PreflightContext const& ctx)
         return temMALFORMED;
     }
 
+    if (ctx.tx.isFieldPresent(sfMemoData) && !ctx.rules.enabled(featureLendingProtocolV1_1))
+        return temDISABLED;
+
+    // The sfMemoData field is an optional field used to record the deletion reason.
+    if (auto const data = ctx.tx[~sfMemoData]; data && !validDataLength(data, maxDataPayloadLength))
+        return temMALFORMED;
+
     return tesSUCCESS;
 }
 

src/test/app/Invariants_test.cpp

@@ -19,9 +19,14 @@
 #include <xrpl/protocol/XRPAmount.h>
 #include <xrpl/tx/ApplyContext.h>
 #include <xrpl/tx/apply.h>
+#include <xrpl/tx/invariants/InvariantCheck.h>
 
 #include <boost/algorithm/string/predicate.hpp>
 
+#include <initializer_list>
+#include <string>
+#include <vector>
+
 namespace xrpl {
 namespace test {
 
@@ -3805,6 +3810,128 @@ class Invariants_test : public beast::unit_test::suite
             precloseMpt);
     }
 
+    void
+    testVaultComputeMinScale()
+    {
+        using namespace jtx;
+
+        Account const issuer{"issuer"};
+        PrettyAsset const vaultAsset = issuer["IOU"];
+
+        struct TestCase
+        {
+            std::string name;
+            std::int32_t expectedMinScale;
+            std::vector<ValidVault::DeltaInfo> values;
+        };
+
+        NumberMantissaScaleGuard g{MantissaRange::large};
+
+        auto makeDelta = [&vaultAsset](Number const& n) -> ValidVault::DeltaInfo {
+            return {n, scale(n, vaultAsset.raw())};
+        };
+
+        auto const testCases = std::vector<TestCase>{
+            {
+                .name = "No values",
+                .expectedMinScale = 0,
+                .values = {},
+            },
+            {
+                .name = "Mixed integer and Number values",
+                .expectedMinScale = -15,
+                .values = {makeDelta(1), makeDelta(-1), makeDelta(Number{10, -1})},
+            },
+            {
+                .name = "Mixed scales",
+                .expectedMinScale = -17,
+                .values =
+                    {makeDelta(Number{1, -2}), makeDelta(Number{5, -3}), makeDelta(Number{3, -2})},
+            },
+            {
+                .name = "Equal scales",
+                .expectedMinScale = -16,
+                .values =
+                    {makeDelta(Number{1, -1}), makeDelta(Number{5, -1}), makeDelta(Number{1, -1})},
+            },
+            {
+                .name = "Mixed mantissa sizes",
+                .expectedMinScale = -12,
+                .values =
+                    {makeDelta(Number{1}),
+                     makeDelta(Number{1234, -3}),
+                     makeDelta(Number{12345, -6}),
+                     makeDelta(Number{123, 1})},
+            },
+        };
+
+        for (auto const& tc : testCases)
+        {
+            testcase("vault computeMinScale: " + tc.name);
+
+            auto const actualScale = ValidVault::computeMinScale(vaultAsset, tc.values);
+
+            BEAST_EXPECTS(
+                actualScale == tc.expectedMinScale,
+                "expected: " + std::to_string(tc.expectedMinScale) +
+                    ", actual: " + std::to_string(actualScale));
+            for (auto const& num : tc.values)
+            {
+                // None of these scales are far enough apart that rounding the
+                // values would lose information, so check that the rounded
+                // value matches the original.
+                auto const actualRounded = roundToAsset(vaultAsset, num.delta, actualScale);
+                BEAST_EXPECTS(
+                    actualRounded == num.delta,
+                    "number " + to_string(num.delta) + " rounded to scale " +
+                        std::to_string(actualScale) + " is " + to_string(actualRounded));
+            }
+        }
+
+        auto const testCases2 = std::vector<TestCase>{
+            {
+                .name = "False equivalence",
+                .expectedMinScale = -15,
+                .values =
+                    {
+                        makeDelta(Number{1234567890123456789, -18}),
+                        makeDelta(Number{12345, -4}),
+                        makeDelta(Number{1}),
+                    },
+            },
+        };
+
+        // Unlike the first set of test cases, the values in these test could
+        // look equivalent if using the wrong scale.
+        for (auto const& tc : testCases2)
+        {
+            testcase("vault computeMinScale: " + tc.name);
+
+            auto const actualScale = ValidVault::computeMinScale(vaultAsset, tc.values);
+
+            BEAST_EXPECTS(
+                actualScale == tc.expectedMinScale,
+                "expected: " + std::to_string(tc.expectedMinScale) +
+                    ", actual: " + std::to_string(actualScale));
+            std::optional<Number> first;
+            Number firstRounded;
+            for (auto const& num : tc.values)
+            {
+                if (!first)
+                {
+                    first = num.delta;
+                    firstRounded = roundToAsset(vaultAsset, num.delta, actualScale);
+                    continue;
+                }
+                auto const numRounded = roundToAsset(vaultAsset, num.delta, actualScale);
+                BEAST_EXPECTS(
+                    numRounded != firstRounded,
+                    "at a scale of " + std::to_string(actualScale) + " " + to_string(num.delta) +
+                        " == " + to_string(*first));
+            }
+        }
+    }
+
 public:
     void
     run() override
@@ -3830,6 +3957,7 @@ public:
         testValidPseudoAccounts();
         testValidLoanBroker();
         testVault();
+        testVaultComputeMinScale();
     }
 };
 

src/test/app/LendingHelpers_test.cpp

@@ -3,7 +3,6 @@
 #include <test/jtx.h>
 #include <test/jtx/Account.h>
 #include <test/jtx/amount.h>
-#include <test/jtx/mpt.h>
 
 #include <xrpl/beast/xor_shift_engine.h>
 #include <xrpl/protocol/SField.h>

src/test/app/LoanBroker_test.cpp

@@ -409,7 +409,7 @@ class LoanBroker_test : public beast::unit_test::suite
             }
 
             // no-op
-            env(set(alice, vault.vaultID), loanBrokerID(keylet.key));
+            env(set(alice), loanBrokerID(keylet.key));
             env.close();
 
             // Make modifications to the broker
@@ -425,10 +425,7 @@ class LoanBroker_test : public beast::unit_test::suite
             // Verify that fields get removed when set to default values
             // Debt maximum: explicit 0
             // Data: explicit empty
-            env(set(alice, vault.vaultID),
-                loanBrokerID(broker->key()),
-                debtMaximum(Number(0)),
-                data(""));
+            env(set(alice), loanBrokerID(broker->key()), debtMaximum(Number(0)), data(""));
             env.close();
 
             // Check the updated fields
@@ -685,26 +682,25 @@ class LoanBroker_test : public beast::unit_test::suite
                     auto const nextKeylet = keylet::loanbroker(alice.id(), env.seq(alice));
 
                     // fields that can't be changed
+
                     // LoanBrokerID
-                    env(set(alice, vault.vaultID), loanBrokerID(nextKeylet.key), ter(tecNO_ENTRY));
-                    // VaultID
-                    env(set(alice, nextKeylet.key), loanBrokerID(broker->key()), ter(tecNO_ENTRY));
+                    env(set(alice), loanBrokerID(nextKeylet.key), ter(tecNO_ENTRY));
+                    // VaultID (rejected in preflight when amendment is active)
+                    env(set(alice, nextKeylet.key), loanBrokerID(broker->key()), ter(temINVALID));
                     // Owner
-                    env(set(evan, vault.vaultID),
-                        loanBrokerID(broker->key()),
-                        ter(tecNO_PERMISSION));
+                    env(set(evan), loanBrokerID(broker->key()), ter(tecNO_PERMISSION));
                     // ManagementFeeRate
-                    env(set(alice, vault.vaultID),
+                    env(set(alice),
                         loanBrokerID(broker->key()),
                         managementFeeRate(maxManagementFeeRate),
                         ter(temINVALID));
                     // CoverRateMinimum
-                    env(set(alice, vault.vaultID),
+                    env(set(alice),
                         loanBrokerID(broker->key()),
                         coverRateMinimum(maxManagementFeeRate),
                         ter(temINVALID));
                     // CoverRateLiquidation
-                    env(set(alice, vault.vaultID),
+                    env(set(alice),
                         loanBrokerID(broker->key()),
                         coverRateLiquidation(maxManagementFeeRate),
                         ter(temINVALID));
@@ -712,20 +708,20 @@ class LoanBroker_test : public beast::unit_test::suite
                     // fields that can be changed
                     testData = "Test Data 1234";
                     // Bad data: too long
-                    env(set(alice, vault.vaultID),
+                    env(set(alice),
                         loanBrokerID(broker->key()),
                         data(std::string(maxDataPayloadLength + 1, 'W')),
                         ter(temINVALID));
 
                     // Bad debt maximum
-                    env(set(alice, vault.vaultID),
+                    env(set(alice),
                         loanBrokerID(broker->key()),
                         debtMaximum(Number(-175, -1)),
                         ter(temINVALID));
                     Number debtMax{175, -1};
                     if (vault.asset.integral())
                     {
-                        env(set(alice, vault.vaultID),
+                        env(set(alice),
                             loanBrokerID(broker->key()),
                             data(testData),
                             debtMaximum(debtMax),
@@ -733,7 +729,7 @@ class LoanBroker_test : public beast::unit_test::suite
                         roundToAsset(vault.asset, debtMax);
                     }
                     // Data & Debt maximum
-                    env(set(alice, vault.vaultID),
+                    env(set(alice),
                         loanBrokerID(broker->key()),
                         data(testData),
                         debtMaximum(debtMax));
@@ -779,10 +775,7 @@ class LoanBroker_test : public beast::unit_test::suite
                 },
                 [&](SLE::const_ref broker) {
                     // Reset Data & Debt maximum to default values
-                    env(set(alice, vault.vaultID),
-                        loanBrokerID(broker->key()),
-                        data(""),
-                        debtMaximum(Number(0)));
+                    env(set(alice), loanBrokerID(broker->key()), data(""), debtMaximum(Number(0)));
                 },
                 [&](SLE::const_ref broker) {
                     // Check the updated fields
@@ -857,17 +850,6 @@ class LoanBroker_test : public beast::unit_test::suite
             // test
             env(jv, txflags(tfFullyCanonicalSig), ter(temINVALID));
         };
-        auto testZeroVaultID = [&](auto&& getTxJv) {
-            auto jv = getTxJv();
-            // empty broker ID
-            jv[sfVaultID] = "";
-            env(jv, ter(temINVALID));
-            // zero broker ID
-            jv[sfVaultID] = to_string(uint256{});
-            // needs a flag to distinguish the parsed STTx from the prior
-            // test
-            env(jv, txflags(tfFullyCanonicalSig), ter(temINVALID));
-        };
 
         if (brokerTest == CoverDeposit)
         {
@@ -1020,13 +1002,8 @@ class LoanBroker_test : public beast::unit_test::suite
         if (brokerTest == Set)
         {
             // preflight: temINVALID (empty/zero broker id)
-            testZeroBrokerID([&]() {
-                return env.json(set(alice, vaultInfo.vaultID), loanBrokerID(brokerKeylet.key));
-            });
-            // preflight: temINVALID (empty/zero vault id)
-            testZeroVaultID([&]() {
-                return env.json(set(alice, vaultInfo.vaultID), loanBrokerID(brokerKeylet.key));
-            });
+            testZeroBrokerID(
+                [&]() { return env.json(set(alice), loanBrokerID(brokerKeylet.key)); });
 
             if (asset.holds<Issue>())
             {
@@ -1375,7 +1352,7 @@ class LoanBroker_test : public beast::unit_test::suite
         BEAST_EXPECT(broker->at(sfDebtTotal) == 50);
         auto debtTotal = broker->at(sfDebtTotal);
 
-        auto tx2 = set(alice, vaultInfo.vaultID);
+        auto tx2 = set(alice);
         tx2[sfLoanBrokerID] = to_string(brokerKeylet.key);
         tx2[sfDebtMaximum] = debtTotal - 1;
         env(tx2, ter(tecLIMIT_EXCEEDED));
@@ -1770,10 +1747,218 @@ class LoanBroker_test : public beast::unit_test::suite
         testRIPD4274MPT();
     }
 
+    void
+    testFeatureLendingProtocolV1_1enabled()
+    {
+        using namespace jtx;
+        testcase("featureLendingProtocolV1_1 enabled");
+        Env env{*this};
+
+        BEAST_EXPECT(env.enabled(featureLendingProtocolV1_1));
+    }
+
+    void
+    testLoanBrokerSetVaultIDAmendment()
+    {
+        using namespace jtx;
+        using namespace loanBroker;
+
+        Account const issuer{"issuer"};
+        Account const alice{"alice"};
+        Account const evan{"evan"};
+
+        // Helper to set up a vault and broker for testing
+        auto const setup = [&](Env& env) {
+            Vault vault{env};
+            env.fund(XRP(100'000), issuer, alice, evan);
+            env.close();
+
+            env(trust(alice, issuer["IOU"](1'000'000)));
+            env.close();
+            PrettyAsset const asset = issuer["IOU"];
+            env(pay(issuer, alice, asset(100'000)));
+            env.close();
+
+            auto [tx, vaultKeylet] = vault.create({.owner = alice, .asset = asset});
+            env(tx);
+            env.close();
+
+            env(vault.deposit({.depositor = alice, .id = vaultKeylet.key, .amount = asset(50)}));
+            env.close();
+
+            auto const brokerKeylet = keylet::loanbroker(alice.id(), env.seq(alice));
+            env(set(alice, vaultKeylet.key));
+            env.close();
+
+            struct Result
+            {
+                uint256 vaultID;
+                Keylet brokerKeylet;
+            };
+            return Result{vaultKeylet.key, brokerKeylet};
+        };
+
+        // Post-amendment: VaultID must not be present on update
+        {
+            testcase("LoanBrokerSet post-amendment: VaultID rejected on update");
+            Env env(*this);
+            BEAST_EXPECT(env.enabled(featureLendingProtocolV1_1));
+            auto const [vaultID, brokerKL] = setup(env);
+
+            // Update with VaultID → temINVALID
+            env(set(alice, vaultID), loanBrokerID(brokerKL.key), ter(temINVALID));
+
+            // Update without VaultID succeeds
+            env(set(alice), loanBrokerID(brokerKL.key), data("post-amendment update"));
+            env.close();
+
+            auto const broker = env.le(brokerKL);
+            BEAST_EXPECT(broker);
+            if (broker)
+                BEAST_EXPECT(checkVL(broker->at(sfData), "post-amendment update"));
+        }
+
+        // Post-amendment: Create requires VaultID
+        {
+            testcase("LoanBrokerSet post-amendment: VaultID required on create");
+            Env env(*this);
+            BEAST_EXPECT(env.enabled(featureLendingProtocolV1_1));
+            env.fund(XRP(100'000), issuer, alice);
+            env.close();
+
+            // Create without VaultID → temINVALID
+            env(set(alice), ter(temINVALID));
+
+            // Create with zero VaultID → temINVALID
+            env(set(alice, uint256{}), ter(temINVALID));
+        }
+
+        // Post-amendment: Update by wrong owner → tecNO_PERMISSION
+        {
+            testcase("LoanBrokerSet post-amendment: wrong owner rejected");
+            Env env(*this);
+            auto const [vaultID, brokerKL] = setup(env);
+
+            env(set(evan), loanBrokerID(brokerKL.key), ter(tecNO_PERMISSION));
+        }
+
+        // Post-amendment: Update non-existent broker → tecNO_ENTRY
+        {
+            testcase("LoanBrokerSet post-amendment: non-existent broker");
+            Env env(*this);
+            env.fund(XRP(100'000), alice);
+            env.close();
+
+            env(set(alice), loanBrokerID(uint256{1}), ter(tecNO_ENTRY));
+        }
+
+        // Pre-amendment: VaultID required on both create and update
+        {
+            testcase("LoanBrokerSet pre-amendment: VaultID required on update");
+            Env env(*this);
+            env.disableFeature(featureLendingProtocolV1_1);
+            BEAST_EXPECT(!env.enabled(featureLendingProtocolV1_1));
+            auto const [vaultID, brokerKL] = setup(env);
+
+            // Update without VaultID → temINVALID (pre-amendment requires it)
+            env(set(alice), loanBrokerID(brokerKL.key), ter(temINVALID));
+
+            // Update with matching VaultID succeeds (old behavior)
+            env(set(alice, vaultID), loanBrokerID(brokerKL.key), data("pre-amendment update"));
+            env.close();
+
+            auto const broker = env.le(brokerKL);
+            BEAST_EXPECT(broker);
+            if (broker)
+                BEAST_EXPECT(checkVL(broker->at(sfData), "pre-amendment update"));
+        }
+
+        // Pre-amendment: mismatched VaultID on update → tecNO_PERMISSION
+        {
+            testcase("LoanBrokerSet pre-amendment: mismatched VaultID");
+            Env env(*this);
+            env.disableFeature(featureLendingProtocolV1_1);
+
+            Vault vault{env};
+            env.fund(XRP(100'000), issuer, alice);
+            env.close();
+            env(trust(alice, issuer["IOU"](1'000'000)));
+            env.close();
+            PrettyAsset const asset = issuer["IOU"];
+            env(pay(issuer, alice, asset(100'000)));
+            env.close();
+
+            // Create two vaults
+            auto [tx1, vaultKL1] = vault.create({.owner = alice, .asset = asset});
+            env(tx1);
+            env.close();
+            auto [tx2, vaultKL2] = vault.create({.owner = alice, .asset = asset});
+            env(tx2);
+            env.close();
+
+            env(vault.deposit({.depositor = alice, .id = vaultKL1.key, .amount = asset(50)}));
+            env.close();
+
+            auto const brokerKL = keylet::loanbroker(alice.id(), env.seq(alice));
+            env(set(alice, vaultKL1.key));
+            env.close();
+
+            // Update with different vault → tecNO_PERMISSION
+            env(set(alice, vaultKL2.key), loanBrokerID(brokerKL.key), ter(tecNO_PERMISSION));
+        }
+
+        // Pre-amendment: non-existent vault on update → tecNO_ENTRY
+        {
+            testcase("LoanBrokerSet pre-amendment: non-existent vault on update");
+            Env env(*this);
+            env.disableFeature(featureLendingProtocolV1_1);
+            auto const [vaultID, brokerKL] = setup(env);
+
+            // Update with a VaultID that doesn't exist
+            env(set(alice, uint256{1}), loanBrokerID(brokerKL.key), ter(tecNO_ENTRY));
+        }
+
+        // Pre-amendment: Create without VaultID → temINVALID
+        {
+            testcase("LoanBrokerSet pre-amendment: create requires VaultID");
+            Env env(*this);
+            env.disableFeature(featureLendingProtocolV1_1);
+            env.fund(XRP(100'000), issuer, alice);
+            env.close();
+
+            env(set(alice), ter(temINVALID));
+        }
+
+        // Pre-amendment: immutable fields still rejected on update
+        {
+            testcase("LoanBrokerSet pre-amendment: immutable fields on update");
+            Env env(*this);
+            env.disableFeature(featureLendingProtocolV1_1);
+            auto const [vaultID, brokerKL] = setup(env);
+
+            env(set(alice, vaultID),
+                loanBrokerID(brokerKL.key),
+                managementFeeRate(TenthBips16(1)),
+                ter(temINVALID));
+        }
+
+        // Pre-amendment: zero VaultID on update → temINVALID
+        {
+            testcase("LoanBrokerSet pre-amendment: zero VaultID on update");
+            Env env(*this);
+            env.disableFeature(featureLendingProtocolV1_1);
+            auto const [vaultID, brokerKL] = setup(env);
+
+            env(set(alice, uint256{}), loanBrokerID(brokerKL.key), ter(temINVALID));
+        }
+    }
+
 public:
     void
     run() override
     {
+        testLoanBrokerSetVaultIDAmendment();
+        testFeatureLendingProtocolV1_1enabled();
         testLoanBrokerSetDebtMaximum();
         testLoanBrokerCoverDepositNullVault();
 

src/test/app/Loan_test.cpp

@@ -2665,7 +2665,7 @@ protected:
                 env(manage(lender, loanKeylet.key, tfLoanDefault), ter(tecNO_PERMISSION));
             });
 
-#if LOANTODO
+#if LOAN_TODO
         // TODO
 
         /*
@@ -5328,7 +5328,7 @@ protected:
         }
     }
 
-#if LOANTODO
+#if LOAN_TODO
     void
     testLoanPayLateFullPaymentBypassesPenalties()
     {
@@ -6983,14 +6983,145 @@ protected:
         BEAST_EXPECT(afterSecondCoverAvailable == 0);
     }
 
+    // Tests that vault withdrawals work correctly when the vault has unrealized
+    // loss from an impaired loan, ensuring the invariant check properly
+    // accounts for the loss.
+    void
+    testWithdrawReflectsUnrealizedLoss()
+    {
+        using namespace jtx;
+        using namespace loan;
+        using namespace std::chrono_literals;
+
+        testcase("Vault withdraw reflects sfLossUnrealized");
+
+        // Test constants
+        static constexpr std::int64_t INITIAL_FUNDING = 1'000'000;
+        static constexpr std::int64_t LENDER_INITIAL_IOU = 5'000'000;
+        static constexpr std::int64_t DEPOSITOR_INITIAL_IOU = 1'000'000;
+        static constexpr std::int64_t BORROWER_INITIAL_IOU = 100'000;
+        static constexpr std::int64_t DEPOSIT_AMOUNT = 5'000;
+        static constexpr std::int64_t PRINCIPAL_AMOUNT = 99;
+        static constexpr std::uint64_t EXPECTED_SHARES_PER_DEPOSITOR = 5'000'000'000;
+        static constexpr std::uint32_t PAYMENT_INTERVAL = 600;
+        static constexpr std::uint32_t PAYMENT_TOTAL = 2;
+
+        Env env(*this, all);
+
+        // Setup accounts
+        Account const issuer{"issuer"};
+        Account const lender{"lender"};
+        Account const depositorA{"lpA"};
+        Account const depositorB{"lpB"};
+        Account const borrower{"borrowerA"};
+
+        env.fund(XRP(INITIAL_FUNDING), issuer, lender, depositorA, depositorB, borrower);
+        env.close();
+
+        // Setup trust lines
+        PrettyAsset const iouAsset = issuer[iouCurrency];
+        env(trust(lender, iouAsset(10'000'000)));
+        env(trust(depositorA, iouAsset(10'000'000)));
+        env(trust(depositorB, iouAsset(10'000'000)));
+        env(trust(borrower, iouAsset(10'000'000)));
+        env.close();
+
+        // Fund accounts with IOUs
+        env(pay(issuer, lender, iouAsset(LENDER_INITIAL_IOU)));
+        env(pay(issuer, depositorA, iouAsset(DEPOSITOR_INITIAL_IOU)));
+        env(pay(issuer, depositorB, iouAsset(DEPOSITOR_INITIAL_IOU)));
+        env(pay(issuer, borrower, iouAsset(BORROWER_INITIAL_IOU)));
+        env.close();
+
+        // Create vault and broker, then add deposits from two depositors
+        auto const broker = createVaultAndBroker(env, iouAsset, lender);
+        Vault v{env};
+
+        env(v.deposit({
+                .depositor = depositorA,
+                .id = broker.vaultKeylet().key,
+                .amount = iouAsset(DEPOSIT_AMOUNT),
+            }),
+            ter(tesSUCCESS));
+        env(v.deposit({
+                .depositor = depositorB,
+                .id = broker.vaultKeylet().key,
+                .amount = iouAsset(DEPOSIT_AMOUNT),
+            }),
+            ter(tesSUCCESS));
+        env.close();
+
+        // Create a loan
+        auto const sleBroker = env.le(keylet::loanbroker(broker.brokerID));
+        if (!BEAST_EXPECT(sleBroker))
+            return;
+
+        auto const loanKeylet = keylet::loan(broker.brokerID, sleBroker->at(sfLoanSequence));
+
+        env(set(borrower, broker.brokerID, PRINCIPAL_AMOUNT),
+            sig(sfCounterpartySignature, lender),
+            paymentTotal(PAYMENT_TOTAL),
+            paymentInterval(PAYMENT_INTERVAL),
+            fee(env.current()->fees().base * 2),
+            ter(tesSUCCESS));
+        env.close();
+
+        // Impair the loan to create unrealized loss
+        env(manage(lender, loanKeylet.key, tfLoanImpair), ter(tesSUCCESS));
+        env.close();
+
+        // Verify unrealized loss is recorded in the vault
+        auto const vaultAfterImpair = env.le(broker.vaultKeylet());
+        if (!BEAST_EXPECT(vaultAfterImpair))
+            return;
+
+        BEAST_EXPECT(
+            vaultAfterImpair->at(sfLossUnrealized) == broker.asset(PRINCIPAL_AMOUNT).value());
+
+        // Helper to get share balance for a depositor
+        auto const shareAsset = vaultAfterImpair->at(sfShareMPTID);
+        auto const getShareBalance = [&](Account const& depositor) -> std::uint64_t {
+            auto const token = env.le(keylet::mptoken(shareAsset, depositor.id()));
+            return token ? token->getFieldU64(sfMPTAmount) : 0;
+        };
+
+        // Verify both depositors have equal shares
+        auto const sharesLpA = getShareBalance(depositorA);
+        auto const sharesLpB = getShareBalance(depositorB);
+        BEAST_EXPECT(sharesLpA == EXPECTED_SHARES_PER_DEPOSITOR);
+        BEAST_EXPECT(sharesLpB == EXPECTED_SHARES_PER_DEPOSITOR);
+        BEAST_EXPECT(sharesLpA == sharesLpB);
+
+        // Helper to attempt withdrawal
+        auto const attemptWithdrawShares = [&](Account const& depositor,
+                                               std::uint64_t shareAmount,
+                                               TER expected) {
+            STAmount const shareAmt{MPTIssue{shareAsset}, Number(shareAmount)};
+            env(v.withdraw(
+                    {.depositor = depositor, .id = broker.vaultKeylet().key, .amount = shareAmt}),
+                ter(expected));
+            env.close();
+        };
+
+        // Regression test: Both depositors should successfully withdraw despite
+        // unrealized loss. Previously failed with invariant violation:
+        // "withdrawal must change vault and destination balance by equal
+        // amount". This was caused by sharesToAssetsWithdraw rounding down,
+        // creating a mismatch where vaultDeltaAssets * -1 != destinationDelta
+        // when unrealized loss exists.
+        attemptWithdrawShares(depositorA, sharesLpA, tesSUCCESS);
+        attemptWithdrawShares(depositorB, sharesLpB, tesSUCCESS);
+    }
+
 public:
     void
     run() override
     {
-#if LOANTODO
+#if LOAN_TODO
         testLoanPayLateFullPaymentBypassesPenalties();
         testLoanCoverMinimumRoundingExploit();
 #endif
+        testWithdrawReflectsUnrealizedLoss();
         testInvalidLoanSet();
 
         testCoverDepositWithdrawNonTransferableMPT();

src/test/app/Vault_test.cpp

@@ -1081,6 +1081,7 @@ class Vault_test : public beast::unit_test::suite
                                 Asset const& asset,
                                 Vault& vault)> test) {
             Env env{*this, testable_amendments() | featureSingleAssetVault};
+
             Account issuer{"issuer"};
             Account owner{"owner"};
             Account depositor{"depositor"};
@@ -5231,6 +5232,63 @@ class Vault_test : public beast::unit_test::suite
         }
     }
 
+    void
+    testVaultDeleteData()
+    {
+        using namespace test::jtx;
+
+        Env env{*this};
+
+        Account const owner{"owner"};
+        env.fund(XRP(1'000'000), owner);
+        env.close();
+
+        Vault vault{env};
+
+        auto const keylet = keylet::vault(owner.id(), 1);
+        auto delTx = vault.del({.owner = owner, .id = keylet.key});
+
+        // Test VaultDelete with featureLendingProtocolV1_1 disabled
+        // Transaction fails if the data field is provided
+        {
+            testcase("VaultDelete data featureLendingProtocolV1_1 disabled");
+            env.disableFeature(featureLendingProtocolV1_1);
+            delTx[sfMemoData] = strHex(std::string(maxDataPayloadLength, 'A'));
+            env(delTx, ter(temDISABLED));
+            env.close();
+            env.enableFeature(featureLendingProtocolV1_1);
+        }
+
+        // Transaction fails if the data field is too large
+        {
+            testcase("VaultDelete data featureLendingProtocolV1_1 enabled data too large");
+            delTx[sfMemoData] = strHex(std::string(maxDataPayloadLength + 1, 'A'));
+            env(delTx, ter(temMALFORMED));
+            env.close();
+        }
+
+        // Transaction fails if the data field is set, but is empty
+        {
+            testcase("VaultDelete data featureLendingProtocolV1_1 enabled data empty");
+            delTx[sfMemoData] = strHex(std::string(0, 'A'));
+            env(delTx, ter(temMALFORMED));
+            env.close();
+        }
+
+        {
+            testcase("VaultDelete data featureLendingProtocolV1_1 enabled data valid");
+            PrettyAsset const xrpAsset = xrpIssue();
+            auto [tx, keylet] = vault.create({.owner = owner, .asset = xrpAsset});
+            env(tx, ter(tesSUCCESS));
+            env.close();
+            // Recreate the transaction as the vault keylet changed
+            auto delTx = vault.del({.owner = owner, .id = keylet.key});
+            delTx[sfMemoData] = strHex(std::string(maxDataPayloadLength, 'A'));
+            env(delTx, ter(tesSUCCESS));
+            env.close();
+        }
+    }
+
 public:
     void
     run() override
@@ -5251,6 +5309,7 @@ public:
         testVaultClawbackBurnShares();
         testVaultClawbackAssets();
         testAssetsMaximum();
+        testVaultDeleteData();
     }
 };
 

src/test/jtx/TestHelpers.h

@@ -680,7 +680,9 @@ checkMetrics(
 namespace loanBroker {
 
 Json::Value
-set(AccountID const& account, uint256 const& vaultId, std::uint32_t flags = 0);
+set(AccountID const& account,
+    std::optional<uint256> const& vaultId = std::nullopt,
+    std::uint32_t flags = 0);
 
 // Use "del" because "delete" is a reserved word in C++.
 Json::Value

src/test/jtx/impl/TestHelpers.cpp

@@ -334,12 +334,13 @@ allPathElements(AccountID const& a, Issue const& iss)
 namespace loanBroker {
 
 Json::Value
-set(AccountID const& account, uint256 const& vaultId, uint32_t flags)
+set(AccountID const& account, std::optional<uint256> const& vaultId, uint32_t flags)
 {
     Json::Value jv;
     jv[sfTransactionType] = jss::LoanBrokerSet;
     jv[sfAccount] = to_string(account);
-    jv[sfVaultID] = to_string(vaultId);
+    if (vaultId)
+        jv[sfVaultID] = to_string(*vaultId);
     jv[sfFlags] = flags;
     return jv;
 }

src/tests/libxrpl/protocol_autogen/transactions/LoanBrokerSetTests.cpp

@@ -39,12 +39,12 @@ TEST(TransactionsLoanBrokerSetTests, BuilderSettersRoundTrip)
 
     LoanBrokerSetBuilder builder{
         accountValue,
-        vaultIDValue,
         sequenceValue,
         feeValue
     };
 
     // Set optional fields
+    builder.setVaultID(vaultIDValue);
     builder.setLoanBrokerID(loanBrokerIDValue);
     builder.setData(dataValue);
     builder.setManagementFeeRate(managementFeeRateValue);
@@ -67,13 +67,15 @@ TEST(TransactionsLoanBrokerSetTests, BuilderSettersRoundTrip)
     EXPECT_EQ(tx.getFee(), feeValue);
 
     // Verify required fields
+    // Verify optional fields
     {
         auto const& expected = vaultIDValue;
-        auto const actual = tx.getVaultID();
-        expectEqualField(expected, actual, "sfVaultID");
+        auto const actualOpt = tx.getVaultID();
+        ASSERT_TRUE(actualOpt.has_value()) << "Optional field sfVaultID should be present";
+        expectEqualField(expected, *actualOpt, "sfVaultID");
+        EXPECT_TRUE(tx.hasVaultID());
     }
 
-    // Verify optional fields
     {
         auto const& expected = loanBrokerIDValue;
         auto const actualOpt = tx.getLoanBrokerID();
@@ -149,11 +151,11 @@ TEST(TransactionsLoanBrokerSetTests, BuilderFromStTxRoundTrip)
     // Build an initial transaction
     LoanBrokerSetBuilder initialBuilder{
         accountValue,
-        vaultIDValue,
         sequenceValue,
         feeValue
     };
 
+    initialBuilder.setVaultID(vaultIDValue);
     initialBuilder.setLoanBrokerID(loanBrokerIDValue);
     initialBuilder.setData(dataValue);
     initialBuilder.setManagementFeeRate(managementFeeRateValue);
@@ -177,13 +179,14 @@ TEST(TransactionsLoanBrokerSetTests, BuilderFromStTxRoundTrip)
     EXPECT_EQ(rebuiltTx.getFee(), feeValue);
 
     // Verify required fields
+    // Verify optional fields
     {
         auto const& expected = vaultIDValue;
-        auto const actual = rebuiltTx.getVaultID();
-        expectEqualField(expected, actual, "sfVaultID");
+        auto const actualOpt = rebuiltTx.getVaultID();
+        ASSERT_TRUE(actualOpt.has_value()) << "Optional field sfVaultID should be present";
+        expectEqualField(expected, *actualOpt, "sfVaultID");
     }
 
-    // Verify optional fields
     {
         auto const& expected = loanBrokerIDValue;
         auto const actualOpt = rebuiltTx.getLoanBrokerID();
@@ -269,11 +272,9 @@ TEST(TransactionsLoanBrokerSetTests, OptionalFieldsReturnNullopt)
     auto const feeValue = canonical_AMOUNT();
 
     // Transaction-specific required field values
-    auto const vaultIDValue = canonical_UINT256();
 
     LoanBrokerSetBuilder builder{
         accountValue,
-        vaultIDValue,
         sequenceValue,
         feeValue
     };
@@ -283,6 +284,8 @@ TEST(TransactionsLoanBrokerSetTests, OptionalFieldsReturnNullopt)
     auto tx = builder.build(publicKey, secretKey);
 
     // Verify optional fields are not present
+    EXPECT_FALSE(tx.hasVaultID());
+    EXPECT_FALSE(tx.getVaultID().has_value());
     EXPECT_FALSE(tx.hasLoanBrokerID());
     EXPECT_FALSE(tx.getLoanBrokerID().has_value());
     EXPECT_FALSE(tx.hasData());

src/tests/libxrpl/protocol_autogen/transactions/VaultDeleteTests.cpp

@@ -30,6 +30,7 @@ TEST(TransactionsVaultDeleteTests, BuilderSettersRoundTrip)
 
     // Transaction-specific field values
     auto const vaultIDValue = canonical_UINT256();
+    auto const memoDataValue = canonical_VL();
 
     VaultDeleteBuilder builder{
         accountValue,
@@ -39,6 +40,7 @@ TEST(TransactionsVaultDeleteTests, BuilderSettersRoundTrip)
     };
 
     // Set optional fields
+    builder.setMemoData(memoDataValue);
 
     auto tx = builder.build(publicKey, secretKey);
 
@@ -62,6 +64,14 @@ TEST(TransactionsVaultDeleteTests, BuilderSettersRoundTrip)
     }
 
     // Verify optional fields
+    {
+        auto const& expected = memoDataValue;
+        auto const actualOpt = tx.getMemoData();
+        ASSERT_TRUE(actualOpt.has_value()) << "Optional field sfMemoData should be present";
+        expectEqualField(expected, *actualOpt, "sfMemoData");
+        EXPECT_TRUE(tx.hasMemoData());
+    }
+
 }
 
 // 2 & 4) Start from an STTx, construct a builder from it, build a new wrapper,
@@ -79,6 +89,7 @@ TEST(TransactionsVaultDeleteTests, BuilderFromStTxRoundTrip)
 
     // Transaction-specific field values
     auto const vaultIDValue = canonical_UINT256();
+    auto const memoDataValue = canonical_VL();
 
     // Build an initial transaction
     VaultDeleteBuilder initialBuilder{
@@ -88,6 +99,7 @@ TEST(TransactionsVaultDeleteTests, BuilderFromStTxRoundTrip)
         feeValue
     };
 
+    initialBuilder.setMemoData(memoDataValue);
 
     auto initialTx = initialBuilder.build(publicKey, secretKey);
 
@@ -112,6 +124,13 @@ TEST(TransactionsVaultDeleteTests, BuilderFromStTxRoundTrip)
     }
 
     // Verify optional fields
+    {
+        auto const& expected = memoDataValue;
+        auto const actualOpt = rebuiltTx.getMemoData();
+        ASSERT_TRUE(actualOpt.has_value()) << "Optional field sfMemoData should be present";
+        expectEqualField(expected, *actualOpt, "sfMemoData");
+    }
+
 }
 
 // 3) Verify wrapper throws when constructed from wrong transaction type.
@@ -142,5 +161,35 @@ TEST(TransactionsVaultDeleteTests, BuilderThrowsOnWrongTxType)
     EXPECT_THROW(VaultDeleteBuilder{wrongTx.getSTTx()}, std::runtime_error);
 }
 
+// 5) Build with only required fields and verify optional fields return nullopt.
+TEST(TransactionsVaultDeleteTests, OptionalFieldsReturnNullopt)
+{
+    // Generate a deterministic keypair for signing
+    auto const [publicKey, secretKey] =
+        generateKeyPair(KeyType::secp256k1, generateSeed("testVaultDeleteNullopt"));
+
+    // Common transaction fields
+    auto const accountValue = calcAccountID(publicKey);
+    std::uint32_t const sequenceValue = 3;
+    auto const feeValue = canonical_AMOUNT();
+
+    // Transaction-specific required field values
+    auto const vaultIDValue = canonical_UINT256();
+
+    VaultDeleteBuilder builder{
+        accountValue,
+        vaultIDValue,
+        sequenceValue,
+        feeValue
+    };
+
+    // Do NOT set optional fields
+
+    auto tx = builder.build(publicKey, secretKey);
+
+    // Verify optional fields are not present
+    EXPECT_FALSE(tx.hasMemoData());
+    EXPECT_FALSE(tx.getMemoData().has_value());
+}
 
 }