Merge fixAMMClawbackRounding amendment into featureAMMClawback amendment

Due to rounding, the LPTokenBalance of the last LP might not match the LP's trustline balance. This was fixed for `AMMWithdraw` in `fixAMMv1_1` by adjusting the LPTokenBalance to be the same as the trustline balance. Since `AMMClawback` is also performing a withdrawal, we need to adjust LPTokenBalance as well in `AMMClawback.`

This change includes:
1. Refactored `verifyAndAdjustLPTokenBalance` function in `AMMUtils`, which both`AMMWithdraw` and `AMMClawback` call to adjust LPTokenBalance.
2. Added the unit test `testLastHolderLPTokenBalance` to test the scenario.
3. Modify the existing unit tests for `fixAMMClawbackRounding`.

include/xrpl/protocol/IOUAmount.h

@@ -97,6 +97,12 @@ public:
 
     static IOUAmount
     minPositiveAmount();
+
+    friend std::ostream&
+    operator<<(std::ostream& os, IOUAmount const& x)
+    {
+        return os << to_string(x);
+    }
 };
 
 inline IOUAmount::IOUAmount(beast::Zero)

include/xrpl/protocol/Rules.h

@@ -28,6 +28,9 @@
 
 namespace ripple {
 
+bool
+isFeatureEnabled(uint256 const& feature);
+
 class DigestAwareReadView;
 
 /** Rules controlling protocol behavior. */

src/libxrpl/protocol/Rules.cpp

@@ -153,4 +153,12 @@ Rules::operator!=(Rules const& other) const
 {
     return !(*this == other);
 }
+
+bool
+isFeatureEnabled(uint256 const& feature)
+{
+    auto const& rules = getCurrentTransactionRules();
+    return rules && rules->enabled(feature);
+}
+
 }  // namespace ripple

src/test/jtx/AMM.h

@@ -125,7 +125,6 @@ class AMM
     STAmount const asset1_;
     STAmount const asset2_;
     uint256 const ammID_;
-    IOUAmount const initialLPTokens_;
     bool log_;
     bool doClose_;
     // Predict next purchase price
@@ -138,6 +137,7 @@ class AMM
     std::uint32_t const fee_;
     AccountID const ammAccount_;
     Issue const lptIssue_;
+    IOUAmount const initialLPTokens_;
 
 public:
     AMM(Env& env,
@@ -194,6 +194,12 @@ public:
         Issue const& issue2,
         std::optional<AccountID> const& account = std::nullopt) const;
 
+    std::tuple<STAmount, STAmount, STAmount>
+    balances(std::optional<AccountID> const& account = std::nullopt) const
+    {
+        return balances(asset1_.get<Issue>(), asset2_.get<Issue>(), account);
+    }
+
     [[nodiscard]] bool
     expectLPTokens(AccountID const& account, IOUAmount const& tokens) const;
 
@@ -428,6 +434,9 @@ private:
 
     [[nodiscard]] bool
     expectAuctionSlot(auto&& cb) const;
+
+    IOUAmount
+    initialTokens();
 };
 
 namespace amm {

src/test/jtx/AMMTest.h

@@ -33,6 +33,15 @@ class AMM;
 
 enum class Fund { All, Acct, Gw, IOUOnly };
 
+struct TestAMMArg
+{
+    std::optional<std::pair<STAmount, STAmount>> pool = std::nullopt;
+    std::uint16_t tfee = 0;
+    std::optional<jtx::ter> ter = std::nullopt;
+    std::vector<FeatureBitset> features = {supported_amendments()};
+    bool noLog = false;
+};
+
 void
 fund(
     jtx::Env& env,
@@ -85,6 +94,11 @@ protected:
         std::uint16_t tfee = 0,
         std::optional<jtx::ter> const& ter = std::nullopt,
         std::vector<FeatureBitset> const& features = {supported_amendments()});
+
+    void
+    testAMM(
+        std::function<void(jtx::AMM&, jtx::Env&)>&& cb,
+        TestAMMArg const& arg);
 };
 
 class AMMTest : public jtx::AMMTestBase

src/test/jtx/Env.h

@@ -646,6 +646,12 @@ public:
     void
     disableFeature(uint256 const feature);
 
+    bool
+    enabled(uint256 feature) const
+    {
+        return current()->rules().enabled(feature);
+    }
+
 private:
     void
     fund(bool setDefaultRipple, STAmount const& amount, Account const& account);

src/test/jtx/impl/AMM.cpp

@@ -18,8 +18,9 @@
 //==============================================================================
 
 #include <test/jtx/AMM.h>
-
 #include <test/jtx/Env.h>
+
+#include <xrpld/app/misc/AMMHelpers.h>
 #include <xrpld/app/misc/AMMUtils.h>
 #include <xrpld/rpc/detail/RPCHelpers.h>
 #include <xrpl/protocol/AMMCore.h>
@@ -38,12 +39,10 @@ number(STAmount const& a)
     return a;
 }
 
-static IOUAmount
-initialTokens(STAmount const& asset1, STAmount const& asset2)
+IOUAmount
+AMM::initialTokens()
 {
-    auto const product = number(asset1) * number(asset2);
-    return (IOUAmount)(product.mantissa() >= 0 ? root2(product)
-                                               : root2(-product));
+    return getLPTokensBalance();
 }
 
 AMM::AMM(
@@ -64,7 +63,6 @@ AMM::AMM(
     , asset1_(asset1)
     , asset2_(asset2)
     , ammID_(keylet::amm(asset1_.issue(), asset2_.issue()).key)
-    , initialLPTokens_(initialTokens(asset1, asset2))
     , log_(log)
     , doClose_(close)
     , lastPurchasePrice_(0)
@@ -77,6 +75,7 @@ AMM::AMM(
           asset1_.issue().currency,
           asset2_.issue().currency,
           ammAccount_))
+    , initialLPTokens_(initialTokens())
 {
 }
 

src/test/jtx/impl/AMMTest.cpp

@@ -17,9 +17,9 @@
 */
 //==============================================================================
 
-#include <test/jtx/AMMTest.h>
-
 #include <test/jtx/AMM.h>
+#include <test/jtx/AMMTest.h>
+#include <test/jtx/CaptureLogs.h>
 #include <test/jtx/Env.h>
 #include <test/jtx/pay.h>
 #include <xrpld/rpc/RPCHandler.h>
@@ -104,15 +104,37 @@ AMMTestBase::testAMM(
     std::uint16_t tfee,
     std::optional<jtx::ter> const& ter,
     std::vector<FeatureBitset> const& vfeatures)
+{
+    testAMM(
+        std::move(cb),
+        TestAMMArg{
+            .pool = pool, .tfee = tfee, .ter = ter, .features = vfeatures});
+}
+
+void
+AMMTestBase::testAMM(
+    std::function<void(jtx::AMM&, jtx::Env&)>&& cb,
+    TestAMMArg const& arg)
 {
     using namespace jtx;
 
-    for (auto const& features : vfeatures)
+    std::string logs;
+
+    for (auto const& features : arg.features)
     {
-        Env env{*this, features};
+        // Env env{
+        //     *this,
+        //     features,
+        //     arg.noLog ? std::make_unique<CaptureLogs>(&logs) : nullptr};
+        Env env(
+            *this,
+            envconfig(),
+            features,
+            nullptr,
+            beast::severities::kDisabled);
 
         auto const [asset1, asset2] =
-            pool ? *pool : std::make_pair(XRP(10000), USD(10000));
+            arg.pool ? *arg.pool : std::make_pair(XRP(10000), USD(10000));
         auto tofund = [&](STAmount const& a) -> STAmount {
             if (a.native())
             {
@@ -142,7 +164,7 @@ AMMTestBase::testAMM(
             alice,
             asset1,
             asset2,
-            CreateArg{.log = false, .tfee = tfee, .err = ter});
+            CreateArg{.log = false, .tfee = arg.tfee, .err = arg.ter});
         if (BEAST_EXPECT(
                 ammAlice.expectBalances(asset1, asset2, ammAlice.tokens())))
             cb(ammAlice, env);

src/test/rpc/AMMInfo_test.cpp

@@ -203,98 +203,107 @@ public:
     }
 
     void
-    testVoteAndBid()
+    testVoteAndBid(FeatureBitset features)
     {
         testcase("Vote and Bid");
 
         using namespace jtx;
-        testAMM([&](AMM& ammAlice, Env& env) {
-            BEAST_EXPECT(ammAlice.expectAmmRpcInfo(
-                XRP(10000), USD(10000), IOUAmount{10000000, 0}));
-            std::unordered_map<std::string, std::uint16_t> votes;
-            votes.insert({alice.human(), 0});
-            for (int i = 0; i < 7; ++i)
-            {
-                Account a(std::to_string(i));
-                votes.insert({a.human(), 50 * (i + 1)});
-                fund(env, gw, {a}, {USD(10000)}, Fund::Acct);
-                ammAlice.deposit(a, 10000000);
-                ammAlice.vote(a, 50 * (i + 1));
-            }
-            BEAST_EXPECT(ammAlice.expectTradingFee(175));
-            Account ed("ed");
-            Account bill("bill");
-            env.fund(XRP(1000), bob, ed, bill);
-            env(ammAlice.bid(
-                {.bidMin = 100, .authAccounts = {carol, bob, ed, bill}}));
-            BEAST_EXPECT(ammAlice.expectAmmRpcInfo(
-                XRP(80000),
-                USD(80000),
-                IOUAmount{79994400},
-                std::nullopt,
-                std::nullopt,
-                ammAlice.ammAccount()));
-            for (auto i = 0; i < 2; ++i)
-            {
-                std::unordered_set<std::string> authAccounts = {
-                    carol.human(), bob.human(), ed.human(), bill.human()};
-                auto const ammInfo = i ? ammAlice.ammRpcInfo()
-                                       : ammAlice.ammRpcInfo(
-                                             std::nullopt,
-                                             std::nullopt,
-                                             std::nullopt,
-                                             std::nullopt,
-                                             ammAlice.ammAccount());
-                auto const& amm = ammInfo[jss::amm];
-                try
+        testAMM(
+            [&](AMM& ammAlice, Env& env) {
+                BEAST_EXPECT(ammAlice.expectAmmRpcInfo(
+                    XRP(10000), USD(10000), IOUAmount{10000000, 0}));
+                std::unordered_map<std::string, std::uint16_t> votes;
+                votes.insert({alice.human(), 0});
+                for (int i = 0; i < 7; ++i)
                 {
-                    // votes
-                    auto const voteSlots = amm[jss::vote_slots];
-                    auto votesCopy = votes;
-                    for (std::uint8_t i = 0; i < 8; ++i)
+                    Account a(std::to_string(i));
+                    votes.insert({a.human(), 50 * (i + 1)});
+                    fund(env, gw, {a}, {USD(10001)}, Fund::Acct);
+                    ammAlice.deposit(a, 10000000);
+                    ammAlice.vote(a, 50 * (i + 1));
+                }
+                BEAST_EXPECT(ammAlice.expectTradingFee(175));
+                Account ed("ed");
+                Account bill("bill");
+                env.fund(XRP(1000), bob, ed, bill);
+                env(ammAlice.bid(
+                    {.bidMin = 100, .authAccounts = {carol, bob, ed, bill}}));
+                BEAST_EXPECT(ammAlice.expectAmmRpcInfo(
+                    XRPAmount(80000000005),
+                    STAmount{USD, UINT64_C(80'000'00000000005), -11},
+                    IOUAmount{79994400},
+                    std::nullopt,
+                    std::nullopt,
+                    ammAlice.ammAccount()));
+                for (auto i = 0; i < 2; ++i)
+                {
+                    std::unordered_set<std::string> authAccounts = {
+                        carol.human(), bob.human(), ed.human(), bill.human()};
+                    auto const ammInfo = i ? ammAlice.ammRpcInfo()
+                                           : ammAlice.ammRpcInfo(
+                                                 std::nullopt,
+                                                 std::nullopt,
+                                                 std::nullopt,
+                                                 std::nullopt,
+                                                 ammAlice.ammAccount());
+                    auto const& amm = ammInfo[jss::amm];
+                    try
                     {
-                        if (!BEAST_EXPECT(
-                                votes[voteSlots[i][jss::account].asString()] ==
-                                    voteSlots[i][jss::trading_fee].asUInt() &&
-                                voteSlots[i][jss::vote_weight].asUInt() ==
-                                    12500))
+                        // votes
+                        auto const voteSlots = amm[jss::vote_slots];
+                        auto votesCopy = votes;
+                        for (std::uint8_t i = 0; i < 8; ++i)
+                        {
+                            if (!BEAST_EXPECT(
+                                    votes[voteSlots[i][jss::account]
+                                              .asString()] ==
+                                        voteSlots[i][jss::trading_fee]
+                                            .asUInt() &&
+                                    voteSlots[i][jss::vote_weight].asUInt() ==
+                                        12500))
+                                return;
+                            votes.erase(voteSlots[i][jss::account].asString());
+                        }
+                        if (!BEAST_EXPECT(votes.empty()))
                             return;
-                        votes.erase(voteSlots[i][jss::account].asString());
-                    }
-                    if (!BEAST_EXPECT(votes.empty()))
-                        return;
-                    votes = votesCopy;
+                        votes = votesCopy;
 
-                    // bid
-                    auto const auctionSlot = amm[jss::auction_slot];
-                    for (std::uint8_t i = 0; i < 4; ++i)
-                    {
-                        if (!BEAST_EXPECT(authAccounts.contains(
+                        // bid
+                        auto const auctionSlot = amm[jss::auction_slot];
+                        for (std::uint8_t i = 0; i < 4; ++i)
+                        {
+                            if (!BEAST_EXPECT(authAccounts.contains(
+                                    auctionSlot[jss::auth_accounts][i]
+                                               [jss::account]
+                                                   .asString())))
+                                return;
+                            authAccounts.erase(
                                 auctionSlot[jss::auth_accounts][i][jss::account]
-                                    .asString())))
+                                    .asString());
+                        }
+                        if (!BEAST_EXPECT(authAccounts.empty()))
                             return;
-                        authAccounts.erase(
-                            auctionSlot[jss::auth_accounts][i][jss::account]
-                                .asString());
+                        BEAST_EXPECT(
+                            auctionSlot[jss::account].asString() ==
+                                alice.human() &&
+                            auctionSlot[jss::discounted_fee].asUInt() == 17 &&
+                            auctionSlot[jss::price][jss::value].asString() ==
+                                "5600" &&
+                            auctionSlot[jss::price][jss::currency].asString() ==
+                                to_string(ammAlice.lptIssue().currency) &&
+                            auctionSlot[jss::price][jss::issuer].asString() ==
+                                to_string(ammAlice.lptIssue().account));
+                    }
+                    catch (std::exception const& e)
+                    {
+                        fail(e.what(), __FILE__, __LINE__);
                     }
-                    if (!BEAST_EXPECT(authAccounts.empty()))
-                        return;
-                    BEAST_EXPECT(
-                        auctionSlot[jss::account].asString() == alice.human() &&
-                        auctionSlot[jss::discounted_fee].asUInt() == 17 &&
-                        auctionSlot[jss::price][jss::value].asString() ==
-                            "5600" &&
-                        auctionSlot[jss::price][jss::currency].asString() ==
-                            to_string(ammAlice.lptIssue().currency) &&
-                        auctionSlot[jss::price][jss::issuer].asString() ==
-                            to_string(ammAlice.lptIssue().account));
                 }
-                catch (std::exception const& e)
-                {
-                    fail(e.what(), __FILE__, __LINE__);
-                }
-            }
-        });
+            },
+            std::nullopt,
+            0,
+            std::nullopt,
+            {features});
     }
 
     void
@@ -337,9 +346,11 @@ public:
     void
     run() override
     {
+        using namespace jtx;
+        auto const all = supported_amendments();
         testErrors();
         testSimpleRpc();
-        testVoteAndBid();
+        testVoteAndBid(all);
         testFreeze();
         testInvalidAmmField();
     }

src/xrpld/app/misc/AMMHelpers.h

@@ -51,6 +51,8 @@ reduceOffer(auto const& amount)
 
 }  // namespace detail
 
+enum class IsDeposit : bool { No = false, Yes = true };
+
 /** Calculate LP Tokens given AMM pool reserves.
  * @param asset1 AMM one side of the pool reserve
  * @param asset2 AMM another side of the pool reserve
@@ -70,7 +72,7 @@ ammLPTokens(
  * @return tokens
  */
 STAmount
-lpTokensIn(
+lpTokensOut(
     STAmount const& asset1Balance,
     STAmount const& asset1Deposit,
     STAmount const& lptAMMBalance,
@@ -99,7 +101,7 @@ ammAssetIn(
  * @return tokens out amount
  */
 STAmount
-lpTokensOut(
+lpTokensIn(
     STAmount const& asset1Balance,
     STAmount const& asset1Withdraw,
     STAmount const& lptAMMBalance,
@@ -113,7 +115,7 @@ lpTokensOut(
  * @return calculated asset amount
  */
 STAmount
-withdrawByTokens(
+ammAssetOut(
     STAmount const& assetBalance,
     STAmount const& lptAMMBalance,
     STAmount const& lpTokens,
@@ -517,13 +519,13 @@ square(Number const& n);
  * withdraw to cancel out the precision loss.
  * @param lptAMMBalance LPT AMM Balance
  * @param lpTokens LP tokens to deposit or withdraw
- * @param isDeposit true if deposit, false if withdraw
+ * @param isDeposit Yes if deposit, No if withdraw
  */
 STAmount
 adjustLPTokens(
     STAmount const& lptAMMBalance,
     STAmount const& lpTokens,
-    bool isDeposit);
+    IsDeposit isDeposit);
 
 /** Calls adjustLPTokens() and adjusts deposit or withdraw amounts if
  * the adjusted LP tokens are less than the provided LP tokens.
@@ -533,7 +535,7 @@ adjustLPTokens(
  * @param lptAMMBalance LPT AMM Balance
  * @param lpTokens LP tokens to deposit or withdraw
  * @param tfee trading fee in basis points
- * @param isDeposit true if deposit, false if withdraw
+ * @param isDeposit Yes if deposit, No if withdraw
  * @return
  */
 std::tuple<STAmount, std::optional<STAmount>, STAmount>
@@ -544,7 +546,7 @@ adjustAmountsByLPTokens(
     STAmount const& lptAMMBalance,
     STAmount const& lpTokens,
     std::uint16_t tfee,
-    bool isDeposit);
+    IsDeposit isDeposit);
 
 /** Positive solution for quadratic equation:
  * x = (-b + sqrt(b**2 + 4*a*c))/(2*a)
@@ -552,6 +554,134 @@ adjustAmountsByLPTokens(
 Number
 solveQuadraticEq(Number const& a, Number const& b, Number const& c);
 
+STAmount
+multiply(STAmount const& amount, Number const& frac, Number::rounding_mode rm);
+
+namespace detail {
+
+inline Number::rounding_mode
+getLPTokenRounding(IsDeposit isDeposit)
+{
+    // Minimize on deposit, maximize on withdraw to ensure
+    // AMM invariant sqrt(poolAsset1 * poolAsset2) >= LPTokensBalance
+    return isDeposit == IsDeposit::Yes ? Number::downward : Number::upward;
+}
+
+inline Number::rounding_mode
+getAssetRounding(IsDeposit isDeposit)
+{
+    // Maximize on deposit, minimize on withdraw to ensure
+    // AMM invariant sqrt(poolAsset1 * poolAsset2) >= LPTokensBalance
+    return isDeposit == IsDeposit::Yes ? Number::upward : Number::downward;
+}
+
+}  // namespace detail
+
+/** Round AMM equal deposit/withdrawal amount. Deposit/withdrawal formulas
+ * calculate the amount as a fractional value of the pool balance. The rounding
+ * takes place on the last step of multiplying the balance by the fraction if
+ * AMMv1_3 is enabled.
+ */
+template <typename A>
+STAmount
+getRoundedAsset(
+    Rules const& rules,
+    STAmount const& balance,
+    A const& frac,
+    IsDeposit isDeposit)
+{
+    auto const rm = detail::getAssetRounding(isDeposit);
+    return multiply(balance, frac, rm);
+}
+
+/** Round AMM single deposit/withdrawal amount.
+ * The lambda's are used to delay evaluation until the function
+ * is executed so that the calculation is not done twice. noRoundCb() is
+ * called if AMMv1_3 is disabled. Otherwise, the rounding is set and
+ * the amount is:
+ *   isDeposit is Yes - the balance multiplied by productCb()
+ *   isDeposit is No - the result of productCb(). The rounding is
+ *     the same for all calculations in productCb()
+ */
+STAmount
+getRoundedAsset(
+    Rules const& rules,
+    std::function<Number()>&& noRoundCb,
+    STAmount const& balance,
+    std::function<Number()>&& productCb,
+    IsDeposit isDeposit);
+
+/** Round AMM deposit/withdrawal LPToken amount. Deposit/withdrawal formulas
+ * calculate the lptokens as a fractional value of the AMM total lptokens.
+ * The rounding takes place on the last step of multiplying the balance by
+ * the fraction if AMMv1_3 is enabled. The tokens are then
+ * adjusted to factor in the loss in precision (we only keep 16 significant
+ * digits) when adding the lptokens to the balance.
+ */
+STAmount
+getRoundedLPTokens(
+    Rules const& rules,
+    STAmount const& balance,
+    Number const& frac,
+    IsDeposit isDeposit);
+
+/** Round AMM single deposit/withdrawal LPToken amount.
+ * The lambda's are used to delay evaluation until the function is executed
+ * so that the calculations are not done twice.
+ * noRoundCb() is called if AMMv1_3 is disabled. Otherwise, the rounding is set
+ * and the lptokens are:
+ *   if isDeposit is Yes - the result of productCb(). The rounding is
+ *     the same for all calculations in productCb()
+ *   if isDeposit is No - the balance multiplied by productCb()
+ * The lptokens are then adjusted to factor in the loss in precision
+ * (we only keep 16 significant digits) when adding the lptokens to the balance.
+ */
+STAmount
+getRoundedLPTokens(
+    Rules const& rules,
+    std::function<Number()>&& noRoundCb,
+    STAmount const& lptAMMBalance,
+    std::function<Number()>&& productCb,
+    IsDeposit isDeposit);
+
+/* Next two functions adjust asset in/out amount to factor in the adjusted
+ * lptokens. The lptokens are calculated from the asset in/out. The lptokens are
+ * then adjusted to factor in the loss in precision. The adjusted lptokens might
+ * be less than the initially calculated tokens. Therefore, the asset in/out
+ * must be adjusted. The rounding might result in the adjusted amount being
+ * greater than the original asset in/out amount. If this happens,
+ * then the original amount is reduced by the difference in the adjusted amount
+ * and the original amount. The actual tokens and the actual adjusted amount
+ * are then recalculated. The minimum of the original and the actual
+ * adjusted amount is returned.
+ */
+std::pair<STAmount, STAmount>
+adjustAssetInByTokens(
+    Rules const& rules,
+    STAmount const& balance,
+    STAmount const& amount,
+    STAmount const& lptAMMBalance,
+    STAmount const& tokens,
+    std::uint16_t tfee);
+std::pair<STAmount, STAmount>
+adjustAssetOutByTokens(
+    Rules const& rules,
+    STAmount const& balance,
+    STAmount const& amount,
+    STAmount const& lptAMMBalance,
+    STAmount const& tokens,
+    std::uint16_t tfee);
+
+/** Find a fraction of tokens after the tokens are adjusted. The fraction
+ * is used to adjust equal deposit/withdraw amount.
+ */
+Number
+adjustFracByTokens(
+    Rules const& rules,
+    STAmount const& lptAMMBalance,
+    STAmount const& tokens,
+    Number const& frac);
+
 }  // namespace ripple
 
 #endif  // RIPPLE_APP_MISC_AMMHELPERS_H_INCLUDED

src/xrpld/app/misc/AMMUtils.h

@@ -123,6 +123,17 @@ isOnlyLiquidityProvider(
     Issue const& ammIssue,
     AccountID const& lpAccount);
 
+/** Due to rounding, the LPTokenBalance of the last LP might
+ * not match the LP's trustline balance. If it's within the tolerance,
+ * update LPTokenBalance to match the LP's trustline balance.
+ */
+Expected<bool, TER>
+verifyAndAdjustLPTokenBalance(
+    Sandbox& sb,
+    STAmount const& lpTokens,
+    std::shared_ptr<SLE>& ammSle,
+    AccountID const& account);
+
 }  // namespace ripple
 
 #endif  // RIPPLE_APP_MISC_AMMUTILS_H_INLCUDED

src/xrpld/app/misc/detail/AMMHelpers.cpp

@@ -27,6 +27,9 @@ ammLPTokens(
     STAmount const& asset2,
     Issue const& lptIssue)
 {
+    // AMM invariant: sqrt(asset1 * asset2) >= LPTokensBalance
+    auto const rounding = Number::downward;
+    NumberRoundModeGuard g(rounding);
     auto const tokens = root2(asset1 * asset2);
     return toSTAmount(lptIssue, tokens);
 }
@@ -38,7 +41,7 @@ ammLPTokens(
  * where f1 = 1 - tfee, f2 = (1 - tfee/2)/f1
  */
 STAmount
-lpTokensIn(
+lpTokensOut(
     STAmount const& asset1Balance,
     STAmount const& asset1Deposit,
     STAmount const& lptAMMBalance,
@@ -48,8 +51,10 @@ lpTokensIn(
     auto const f2 = feeMultHalf(tfee) / f1;
     Number const r = asset1Deposit / asset1Balance;
     auto const c = root2(f2 * f2 + r / f1) - f2;
-    auto const t = lptAMMBalance * (r - c) / (1 + c);
-    return toSTAmount(lptAMMBalance.issue(), t);
+
+    // minimize tokens out
+    auto const frac = (r - c) / (1 + c);
+    return multiply(lptAMMBalance, frac, Number::downward);
 }
 
 /* Equation 4 solves equation 3 for b:
@@ -78,8 +83,10 @@ ammAssetIn(
     auto const a = 1 / (t2 * t2);
     auto const b = 2 * d / t2 - 1 / f1;
     auto const c = d * d - f2 * f2;
-    return toSTAmount(
-        asset1Balance.issue(), asset1Balance * solveQuadraticEq(a, b, c));
+
+    // maximize deposit
+    auto const frac = solveQuadraticEq(a, b, c);
+    return multiply(asset1Balance, frac, Number::upward);
 }
 
 /* Equation 7:
@@ -87,7 +94,7 @@ ammAssetIn(
  * where R = b/B, c = R*fee + 2 - fee
  */
 STAmount
-lpTokensOut(
+lpTokensIn(
     STAmount const& asset1Balance,
     STAmount const& asset1Withdraw,
     STAmount const& lptAMMBalance,
@@ -96,8 +103,10 @@ lpTokensOut(
     Number const fr = asset1Withdraw / asset1Balance;
     auto const f1 = getFee(tfee);
     auto const c = fr * f1 + 2 - f1;
-    auto const t = lptAMMBalance * (c - root2(c * c - 4 * fr)) / 2;
-    return toSTAmount(lptAMMBalance.issue(), t);
+
+    // maximize tokens in
+    auto const frac = (c - root2(c * c - 4 * fr)) / 2;
+    return multiply(lptAMMBalance, frac, Number::upward);
 }
 
 /* Equation 8 solves equation 7 for b:
@@ -111,7 +120,7 @@ lpTokensOut(
  * R = (t1**2 + t1*(f - 2)) / (t1*f - 1)
  */
 STAmount
-withdrawByTokens(
+ammAssetOut(
     STAmount const& assetBalance,
     STAmount const& lptAMMBalance,
     STAmount const& lpTokens,
@@ -119,8 +128,10 @@ withdrawByTokens(
 {
     auto const f = getFee(tfee);
     Number const t1 = lpTokens / lptAMMBalance;
-    auto const b = assetBalance * (t1 * t1 - t1 * (2 - f)) / (t1 * f - 1);
-    return toSTAmount(assetBalance.issue(), b);
+
+    // minimize withdraw
+    auto const frac = (t1 * t1 - t1 * (2 - f)) / (t1 * f - 1);
+    return multiply(assetBalance, frac, Number::downward);
 }
 
 Number
@@ -133,12 +144,12 @@ STAmount
 adjustLPTokens(
     STAmount const& lptAMMBalance,
     STAmount const& lpTokens,
-    bool isDeposit)
+    IsDeposit isDeposit)
 {
     // Force rounding downward to ensure adjusted tokens are less or equal
     // to requested tokens.
     saveNumberRoundMode rm(Number::setround(Number::rounding_mode::downward));
-    if (isDeposit)
+    if (isDeposit == IsDeposit::Yes)
         return (lptAMMBalance + lpTokens) - lptAMMBalance;
     return (lpTokens - lptAMMBalance) + lptAMMBalance;
 }
@@ -151,47 +162,10 @@ adjustAmountsByLPTokens(
     STAmount const& lptAMMBalance,
     STAmount const& lpTokens,
     std::uint16_t tfee,
-    bool isDeposit)
+    IsDeposit isDeposit)
 {
-    auto const lpTokensActual =
-        adjustLPTokens(lptAMMBalance, lpTokens, isDeposit);
-
-    if (lpTokensActual == beast::zero)
-    {
-        auto const amount2Opt =
-            amount2 ? std::make_optional(STAmount{}) : std::nullopt;
-        return std::make_tuple(STAmount{}, amount2Opt, lpTokensActual);
-    }
-
-    if (lpTokensActual < lpTokens)
-    {
-        // Equal trade
-        if (amount2)
-        {
-            Number const fr = lpTokensActual / lpTokens;
-            auto const amountActual = toSTAmount(amount.issue(), fr * amount);
-            auto const amount2Actual =
-                toSTAmount(amount2->issue(), fr * *amount2);
-            return std::make_tuple(amountActual, amount2Actual, lpTokensActual);
-        }
-
-        // Single trade
-        auto const amountActual = [&]() {
-            if (isDeposit)
-                return ammAssetIn(
-                    amountBalance, lptAMMBalance, lpTokensActual, tfee);
-            return withdrawByTokens(
-                amountBalance, lptAMMBalance, lpTokensActual, tfee);
-        }();
-
-        return std::make_tuple(amountActual, std::nullopt, lpTokensActual);
-    }
-
-    XRPL_ASSERT(
-        lpTokensActual == lpTokens,
-        "ripple::adjustAmountsByLPTokens : LP tokens match actual");
-
-    return {amount, amount2, lpTokensActual};
+    // AMMv1_3 amendment adjusts tokens and amounts in deposit/withdraw
+    return std::make_tuple(amount, amount2, lpTokens);
 }
 
 Number
@@ -215,4 +189,117 @@ solveQuadraticEqSmallest(Number const& a, Number const& b, Number const& c)
         return (2 * c) / (-b + root2(d));
 }
 
+STAmount
+multiply(STAmount const& amount, Number const& frac, Number::rounding_mode rm)
+{
+    NumberRoundModeGuard g(rm);
+    auto const t = amount * frac;
+    return toSTAmount(amount.issue(), t, rm);
+}
+
+STAmount
+getRoundedAsset(
+    Rules const& rules,
+    std::function<Number()>&& noRoundCb,
+    STAmount const& balance,
+    std::function<Number()>&& productCb,
+    IsDeposit isDeposit)
+{
+    auto const rm = detail::getAssetRounding(isDeposit);
+    if (isDeposit == IsDeposit::Yes)
+        return multiply(balance, productCb(), rm);
+    NumberRoundModeGuard g(rm);
+    return toSTAmount(balance.issue(), productCb(), rm);
+}
+
+STAmount
+getRoundedLPTokens(
+    Rules const& rules,
+    STAmount const& balance,
+    Number const& frac,
+    IsDeposit isDeposit)
+{
+    auto const rm = detail::getLPTokenRounding(isDeposit);
+    auto const tokens = multiply(balance, frac, rm);
+    return adjustLPTokens(balance, tokens, isDeposit);
+}
+
+STAmount
+getRoundedLPTokens(
+    Rules const& rules,
+    std::function<Number()>&& noRoundCb,
+    STAmount const& lptAMMBalance,
+    std::function<Number()>&& productCb,
+    IsDeposit isDeposit)
+{
+    auto const tokens = [&] {
+        auto const rm = detail::getLPTokenRounding(isDeposit);
+        if (isDeposit == IsDeposit::Yes)
+        {
+            NumberRoundModeGuard g(rm);
+            return toSTAmount(lptAMMBalance.issue(), productCb(), rm);
+        }
+        return multiply(lptAMMBalance, productCb(), rm);
+    }();
+    return adjustLPTokens(lptAMMBalance, tokens, isDeposit);
+}
+
+std::pair<STAmount, STAmount>
+adjustAssetInByTokens(
+    Rules const& rules,
+    STAmount const& balance,
+    STAmount const& amount,
+    STAmount const& lptAMMBalance,
+    STAmount const& tokens,
+    std::uint16_t tfee)
+{
+    auto assetAdj = ammAssetIn(balance, lptAMMBalance, tokens, tfee);
+    auto tokensAdj = tokens;
+    // Rounding didn't work the right way.
+    // Try to adjust the original deposit amount by difference
+    // in adjust and original amount. Then adjust tokens and deposit amount.
+    if (assetAdj > amount)
+    {
+        auto const adjAmount = amount - (assetAdj - amount);
+        auto const t = lpTokensOut(balance, adjAmount, lptAMMBalance, tfee);
+        tokensAdj = adjustLPTokens(lptAMMBalance, t, IsDeposit::Yes);
+        assetAdj = ammAssetIn(balance, lptAMMBalance, tokensAdj, tfee);
+    }
+    return {tokensAdj, std::min(amount, assetAdj)};
+}
+
+std::pair<STAmount, STAmount>
+adjustAssetOutByTokens(
+    Rules const& rules,
+    STAmount const& balance,
+    STAmount const& amount,
+    STAmount const& lptAMMBalance,
+    STAmount const& tokens,
+    std::uint16_t tfee)
+{
+    auto assetAdj = ammAssetOut(balance, lptAMMBalance, tokens, tfee);
+    auto tokensAdj = tokens;
+    // Rounding didn't work the right way.
+    // Try to adjust the original deposit amount by difference
+    // in adjust and original amount. Then adjust tokens and deposit amount.
+    if (assetAdj > amount)
+    {
+        auto const adjAmount = amount - (assetAdj - amount);
+        auto const t = lpTokensIn(balance, adjAmount, lptAMMBalance, tfee);
+        tokensAdj = adjustLPTokens(lptAMMBalance, t, IsDeposit::No);
+        assetAdj = ammAssetOut(balance, lptAMMBalance, tokensAdj, tfee);
+    }
+    return {tokensAdj, std::min(amount, assetAdj)};
+}
+
+Number
+adjustFracByTokens(
+    Rules const& rules,
+    STAmount const& lptAMMBalance,
+    STAmount const& tokens,
+    Number const& frac)
+{
+    return tokens / lptAMMBalance;
+}
+
 }  // namespace ripple

src/xrpld/app/misc/detail/AMMUtils.cpp

@@ -16,6 +16,8 @@
     OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
 //==============================================================================
+
+#include <xrpld/app/misc/AMMHelpers.h>
 #include <xrpld/app/misc/AMMUtils.h>
 #include <xrpld/ledger/Sandbox.h>
 #include <xrpl/basics/Log.h>
@@ -462,4 +464,32 @@ isOnlyLiquidityProvider(
     return Unexpected<TER>(tecINTERNAL);  // LCOV_EXCL_LINE
 }
 
+Expected<bool, TER>
+verifyAndAdjustLPTokenBalance(
+    Sandbox& sb,
+    STAmount const& lpTokens,
+    std::shared_ptr<SLE>& ammSle,
+    AccountID const& account)
+{
+    if (auto const res = isOnlyLiquidityProvider(sb, lpTokens.issue(), account);
+        !res)
+        return Unexpected<TER>(res.error());
+    else if (res.value())
+    {
+        if (withinRelativeDistance(
+                lpTokens,
+                ammSle->getFieldAmount(sfLPTokenBalance),
+                Number{1, -3}))
+        {
+            ammSle->setFieldAmount(sfLPTokenBalance, lpTokens);
+            sb.update(ammSle);
+        }
+        else
+        {
+            return Unexpected<TER>(tecAMM_INVALID_TOKENS);
+        }
+    }
+    return true;
+}
+
 }  // namespace ripple

src/xrpld/app/tx/detail/AMMBid.cpp

@@ -79,6 +79,21 @@ AMMBid::preflight(PreflightContext const& ctx)
             JLOG(ctx.j.debug()) << "AMM Bid: Invalid number of AuthAccounts.";
             return temMALFORMED;
         }
+        else
+        {
+            AccountID account = ctx.tx[sfAccount];
+            std::set<AccountID> unique;
+            for (auto const& obj : authAccounts)
+            {
+                auto authAccount = obj[sfAccount];
+                if (authAccount == account || unique.contains(authAccount))
+                {
+                    JLOG(ctx.j.debug()) << "AMM Bid: Invalid auth.account.";
+                    return temMALFORMED;
+                }
+                unique.insert(authAccount);
+            }
+        }
     }
 
     return preflight2(ctx);
@@ -233,7 +248,9 @@ applyBid(
             auctionSlot.makeFieldAbsent(sfAuthAccounts);
         // Burn the remaining bid amount
         auto const saBurn = adjustLPTokens(
-            lptAMMBalance, toSTAmount(lptAMMBalance.issue(), burn), false);
+            lptAMMBalance,
+            toSTAmount(lptAMMBalance.issue(), burn),
+            IsDeposit::No);
         if (saBurn >= lptAMMBalance)
         {
             // This error case should never occur.

src/xrpld/app/tx/detail/AMMClawback.cpp

@@ -151,6 +151,17 @@ AMMClawback::applyGuts(Sandbox& sb)
     if (!accountSle)
         return tecINTERNAL;  // LCOV_EXCL_LINE
 
+    // retrieve LP token balance inside the amendment gate to avoid
+    // inconsistent error behavior
+    auto const lpTokenBalance = ammLPHolds(sb, *ammSle, holder, j_);
+    if (lpTokenBalance == beast::zero)
+        return tecAMM_BALANCE;
+
+    if (auto const res =
+            verifyAndAdjustLPTokenBalance(sb, lpTokenBalance, ammSle, holder);
+        !res)
+        return res.error();  // LCOV_EXCL_LINE
+
     auto const expected = ammHolds(
         sb,
         *ammSle,
@@ -248,10 +259,11 @@ AMMClawback::equalWithdrawMatchingOneAmount(
     STAmount const& amount)
 {
     auto frac = Number{amount} / amountBalance;
-    auto const amount2Withdraw = amount2Balance * frac;
+    auto amount2Withdraw = amount2Balance * frac;
 
     auto const lpTokensWithdraw =
         toSTAmount(lptAMMBalance.issue(), lptAMMBalance * frac);
+
     if (lpTokensWithdraw > holdLPtokens)
         // if lptoken balance less than what the issuer intended to clawback,
         // clawback all the tokens. Because we are doing a two-asset withdrawal,
@@ -272,18 +284,33 @@ AMMClawback::equalWithdrawMatchingOneAmount(
             mPriorBalance,
             ctx_.journal);
 
-    // Because we are doing a two-asset withdrawal,
-    // tfee is actually not used, so pass tfee as 0.
+    auto const& rules = sb.rules();
+
+    auto tokensAdj =
+        getRoundedLPTokens(rules, lptAMMBalance, frac, IsDeposit::No);
+
+    // LCOV_EXCL_START
+    if (tokensAdj == beast::zero)
+        return {tecAMM_INVALID_TOKENS, STAmount{}, STAmount{}, std::nullopt};
+    // LCOV_EXCL_STOP
+
+    frac = adjustFracByTokens(rules, lptAMMBalance, tokensAdj, frac);
+    auto amount2Rounded =
+        getRoundedAsset(rules, amount2Balance, frac, IsDeposit::No);
+
+    auto amountRounded =
+        getRoundedAsset(rules, amountBalance, frac, IsDeposit::No);
+
     return AMMWithdraw::withdraw(
         sb,
         ammSle,
         ammAccount,
         holder,
         amountBalance,
-        amount,
-        toSTAmount(amount2Balance.issue(), amount2Withdraw),
+        amountRounded,
+        amount2Rounded,
         lptAMMBalance,
-        toSTAmount(lptAMMBalance.issue(), lptAMMBalance * frac),
+        tokensAdj,
         0,
         FreezeHandling::fhIGNORE_FREEZE,
         WithdrawAll::No,

src/xrpld/app/tx/detail/AMMDeposit.cpp

@@ -545,7 +545,7 @@ AMMDeposit::deposit(
                 lptAMMBalance,
                 lpTokensDeposit,
                 tfee,
-                true);
+                IsDeposit::Yes);
 
     if (lpTokensDepositActual <= beast::zero)
     {
@@ -628,6 +628,15 @@ AMMDeposit::deposit(
     return {tesSUCCESS, lptAMMBalance + lpTokensDepositActual};
 }
 
+static STAmount
+adjustLPTokensOut(
+    Rules const& rules,
+    STAmount const& lptAMMBalance,
+    STAmount const& lpTokensDeposit)
+{
+    return adjustLPTokens(lptAMMBalance, lpTokensDeposit, IsDeposit::Yes);
+}
+
 /** Proportional deposit of pools assets in exchange for the specified
  * amount of LPTokens.
  */
@@ -645,16 +654,25 @@ AMMDeposit::equalDepositTokens(
 {
     try
     {
+        auto const tokensAdj =
+            adjustLPTokensOut(view.rules(), lptAMMBalance, lpTokensDeposit);
+        if (tokensAdj == beast::zero)
+            return {tecAMM_INVALID_TOKENS, STAmount{}};
         auto const frac =
-            divide(lpTokensDeposit, lptAMMBalance, lptAMMBalance.issue());
+            divide(tokensAdj, lptAMMBalance, lptAMMBalance.issue());
+        // amounts factor in the adjusted tokens
+        auto const amountDeposit =
+            getRoundedAsset(view.rules(), amountBalance, frac, IsDeposit::Yes);
+        auto const amount2Deposit =
+            getRoundedAsset(view.rules(), amount2Balance, frac, IsDeposit::Yes);
         return deposit(
             view,
             ammAccount,
             amountBalance,
-            multiply(amountBalance, frac, amountBalance.issue()),
-            multiply(amount2Balance, frac, amount2Balance.issue()),
+            amountDeposit,
+            amount2Deposit,
             lptAMMBalance,
-            lpTokensDeposit,
+            tokensAdj,
             depositMin,
             deposit2Min,
             std::nullopt,
@@ -711,37 +729,49 @@ AMMDeposit::equalDepositLimit(
     std::uint16_t tfee)
 {
     auto frac = Number{amount} / amountBalance;
-    auto tokens = toSTAmount(lptAMMBalance.issue(), lptAMMBalance * frac);
-    if (tokens == beast::zero)
-        return {tecAMM_FAILED, STAmount{}};
-    auto const amount2Deposit = amount2Balance * frac;
+    auto tokensAdj =
+        getRoundedLPTokens(view.rules(), lptAMMBalance, frac, IsDeposit::Yes);
+    if (tokensAdj == beast::zero)
+    {
+        return {tecAMM_INVALID_TOKENS, STAmount{}};
+    }
+    // factor in the adjusted tokens
+    frac = adjustFracByTokens(view.rules(), lptAMMBalance, tokensAdj, frac);
+    auto const amount2Deposit =
+        getRoundedAsset(view.rules(), amount2Balance, frac, IsDeposit::Yes);
     if (amount2Deposit <= amount2)
         return deposit(
             view,
             ammAccount,
             amountBalance,
             amount,
-            toSTAmount(amount2Balance.issue(), amount2Deposit),
+            amount2Deposit,
             lptAMMBalance,
-            tokens,
+            tokensAdj,
             std::nullopt,
             std::nullopt,
             lpTokensDepositMin,
             tfee);
     frac = Number{amount2} / amount2Balance;
-    tokens = toSTAmount(lptAMMBalance.issue(), lptAMMBalance * frac);
-    if (tokens == beast::zero)
-        return {tecAMM_FAILED, STAmount{}};
-    auto const amountDeposit = amountBalance * frac;
+    tokensAdj =
+        getRoundedLPTokens(view.rules(), lptAMMBalance, frac, IsDeposit::Yes);
+    if (tokensAdj == beast::zero)
+    {
+        return {tecAMM_INVALID_TOKENS, STAmount{}};  // LCOV_EXCL_LINE
+    }
+    // factor in the adjusted tokens
+    frac = adjustFracByTokens(view.rules(), lptAMMBalance, tokensAdj, frac);
+    auto const amountDeposit =
+        getRoundedAsset(view.rules(), amountBalance, frac, IsDeposit::Yes);
     if (amountDeposit <= amount)
         return deposit(
             view,
             ammAccount,
             amountBalance,
-            toSTAmount(amountBalance.issue(), amountDeposit),
+            amountDeposit,
             amount2,
             lptAMMBalance,
-            tokens,
+            tokensAdj,
             std::nullopt,
             std::nullopt,
             lpTokensDepositMin,
@@ -767,17 +797,27 @@ AMMDeposit::singleDeposit(
     std::optional<STAmount> const& lpTokensDepositMin,
     std::uint16_t tfee)
 {
-    auto const tokens = lpTokensIn(amountBalance, amount, lptAMMBalance, tfee);
+    auto const tokens = adjustLPTokensOut(
+        view.rules(),
+        lptAMMBalance,
+        lpTokensOut(amountBalance, amount, lptAMMBalance, tfee));
     if (tokens == beast::zero)
-        return {tecAMM_FAILED, STAmount{}};
+    {
+        return {tecAMM_INVALID_TOKENS, STAmount{}};
+    }
+    // factor in the adjusted tokens
+    auto const [tokensAdj, amountDepositAdj] = adjustAssetInByTokens(
+        view.rules(), amountBalance, amount, lptAMMBalance, tokens, tfee);
+    if (tokensAdj == beast::zero)
+        return {tecAMM_INVALID_TOKENS, STAmount{}};  // LCOV_EXCL_LINE
     return deposit(
         view,
         ammAccount,
         amountBalance,
-        amount,
+        amountDepositAdj,
         std::nullopt,
         lptAMMBalance,
-        tokens,
+        tokensAdj,
         std::nullopt,
         std::nullopt,
         lpTokensDepositMin,
@@ -801,8 +841,13 @@ AMMDeposit::singleDepositTokens(
     STAmount const& lpTokensDeposit,
     std::uint16_t tfee)
 {
+    auto const tokensAdj =
+        adjustLPTokensOut(view.rules(), lptAMMBalance, lpTokensDeposit);
+    if (tokensAdj == beast::zero)
+        return {tecAMM_INVALID_TOKENS, STAmount{}};
+    // the adjusted tokens are factored in
     auto const amountDeposit =
-        ammAssetIn(amountBalance, lptAMMBalance, lpTokensDeposit, tfee);
+        ammAssetIn(amountBalance, lptAMMBalance, tokensAdj, tfee);
     if (amountDeposit > amount)
         return {tecAMM_FAILED, STAmount{}};
     return deposit(
@@ -812,7 +857,7 @@ AMMDeposit::singleDepositTokens(
         amountDeposit,
         std::nullopt,
         lptAMMBalance,
-        lpTokensDeposit,
+        tokensAdj,
         std::nullopt,
         std::nullopt,
         std::nullopt,
@@ -856,20 +901,29 @@ AMMDeposit::singleDepositEPrice(
 {
     if (amount != beast::zero)
     {
-        auto const tokens =
-            lpTokensIn(amountBalance, amount, lptAMMBalance, tfee);
+        auto const tokens = adjustLPTokensOut(
+            view.rules(),
+            lptAMMBalance,
+            lpTokensOut(amountBalance, amount, lptAMMBalance, tfee));
         if (tokens <= beast::zero)
-            return {tecAMM_FAILED, STAmount{}};
-        auto const ep = Number{amount} / tokens;
+        {
+            return {tecAMM_INVALID_TOKENS, STAmount{}};
+        }
+        // factor in the adjusted tokens
+        auto const [tokensAdj, amountDepositAdj] = adjustAssetInByTokens(
+            view.rules(), amountBalance, amount, lptAMMBalance, tokens, tfee);
+        if (tokensAdj == beast::zero)
+            return {tecAMM_INVALID_TOKENS, STAmount{}};  // LCOV_EXCL_LINE
+        auto const ep = Number{amountDepositAdj} / tokensAdj;
         if (ep <= ePrice)
             return deposit(
                 view,
                 ammAccount,
                 amountBalance,
-                amount,
+                amountDepositAdj,
                 std::nullopt,
                 lptAMMBalance,
-                tokens,
+                tokensAdj,
                 std::nullopt,
                 std::nullopt,
                 std::nullopt,
@@ -900,21 +954,37 @@ AMMDeposit::singleDepositEPrice(
     auto const a1 = c * c;
     auto const b1 = c * c * f2 * f2 + 2 * c - d * d;
     auto const c1 = 2 * c * f2 * f2 + 1 - 2 * d * f2;
-    auto const amountDeposit = toSTAmount(
-        amountBalance.issue(),
-        f1 * amountBalance * solveQuadraticEq(a1, b1, c1));
+    auto amtNoRoundCb = [&] {
+        return f1 * amountBalance * solveQuadraticEq(a1, b1, c1);
+    };
+    auto amtProdCb = [&] { return f1 * solveQuadraticEq(a1, b1, c1); };
+    auto const amountDeposit = getRoundedAsset(
+        view.rules(), amtNoRoundCb, amountBalance, amtProdCb, IsDeposit::Yes);
     if (amountDeposit <= beast::zero)
         return {tecAMM_FAILED, STAmount{}};
-    auto const tokens =
-        toSTAmount(lptAMMBalance.issue(), amountDeposit / ePrice);
+    auto tokNoRoundCb = [&] { return amountDeposit / ePrice; };
+    auto tokProdCb = [&] { return amountDeposit / ePrice; };
+    auto const tokens = getRoundedLPTokens(
+        view.rules(), tokNoRoundCb, lptAMMBalance, tokProdCb, IsDeposit::Yes);
+    // factor in the adjusted tokens
+    auto const [tokensAdj, amountDepositAdj] = adjustAssetInByTokens(
+        view.rules(),
+        amountBalance,
+        amountDeposit,
+        lptAMMBalance,
+        tokens,
+        tfee);
+    if (tokensAdj == beast::zero)
+        return {tecAMM_INVALID_TOKENS, STAmount{}};  // LCOV_EXCL_LINE
+
     return deposit(
         view,
         ammAccount,
         amountBalance,
-        amountDeposit,
+        amountDepositAdj,
         std::nullopt,
         lptAMMBalance,
-        tokens,
+        tokensAdj,
         std::nullopt,
         std::nullopt,
         std::nullopt,

src/xrpld/app/tx/detail/AMMWithdraw.cpp

@@ -313,24 +313,9 @@ AMMWithdraw::applyGuts(Sandbox& sb)
     // might not match the LP's trustline balance
 
     if (auto const res =
-            isOnlyLiquidityProvider(sb, lpTokens.issue(), account_);
+            verifyAndAdjustLPTokenBalance(sb, lpTokens, ammSle, account_);
         !res)
         return {res.error(), false};
-    else if (res.value())
-    {
-        if (withinRelativeDistance(
-                lpTokens,
-                ammSle->getFieldAmount(sfLPTokenBalance),
-                Number{1, -3}))
-        {
-            ammSle->setFieldAmount(sfLPTokenBalance, lpTokens);
-            sb.update(ammSle);
-        }
-        else
-        {
-            return {tecAMM_INVALID_TOKENS, false};
-        }
-    }
 
     auto const tfee = getTradingFee(ctx_.view(), *ammSle, account_);
 
@@ -523,7 +508,7 @@ AMMWithdraw::withdraw(
                 lpTokensAMMBalance,
                 lpTokensWithdraw,
                 tfee,
-                false);
+                IsDeposit::No);
         return std::make_tuple(
             amountWithdraw, amount2Withdraw, lpTokensWithdraw);
     }();
@@ -682,6 +667,20 @@ AMMWithdraw::withdraw(
         amount2WithdrawActual);
 }
 
+static STAmount
+adjustLPTokensIn(
+    Rules const& rules,
+    STAmount const& lptAMMBalance,
+    STAmount const& lpTokensWithdraw,
+    WithdrawAll withdrawAll)
+{
+    if (withdrawAll == WithdrawAll::Yes)
+        return lpTokensWithdraw;
+    return adjustLPTokens(lptAMMBalance, lpTokensWithdraw, IsDeposit::No);
+}
+
+/** Proportional withdrawal of pool assets for the amount of LPTokens.
+ */
 std::pair<TER, STAmount>
 AMMWithdraw::equalWithdrawTokens(
     Sandbox& view,
@@ -785,16 +784,22 @@ AMMWithdraw::equalWithdrawTokens(
                 journal);
         }
 
-        auto const frac = divide(lpTokensWithdraw, lptAMMBalance, noIssue());
-        auto const withdrawAmount =
-            multiply(amountBalance, frac, amountBalance.issue());
-        auto const withdraw2Amount =
-            multiply(amount2Balance, frac, amount2Balance.issue());
+        auto const tokensAdj = adjustLPTokensIn(
+            view.rules(), lptAMMBalance, lpTokensWithdraw, withdrawAll);
+        if (tokensAdj == beast::zero)
+            return {
+                tecAMM_INVALID_TOKENS, STAmount{}, STAmount{}, std::nullopt};
+        // the adjusted tokens are factored in
+        auto const frac = divide(tokensAdj, lptAMMBalance, noIssue());
+        auto const amountWithdraw =
+            getRoundedAsset(view.rules(), amountBalance, frac, IsDeposit::No);
+        auto const amount2Withdraw =
+            getRoundedAsset(view.rules(), amount2Balance, frac, IsDeposit::No);
         // LP is making equal withdrawal by tokens but the requested amount
         // of LP tokens is likely too small and results in one-sided pool
         // withdrawal due to round off. Fail so the user withdraws
         // more tokens.
-        if (withdrawAmount == beast::zero || withdraw2Amount == beast::zero)
+        if (amountWithdraw == beast::zero || amount2Withdraw == beast::zero)
             return {tecAMM_FAILED, STAmount{}, STAmount{}, STAmount{}};
 
         return withdraw(
@@ -803,10 +808,10 @@ AMMWithdraw::equalWithdrawTokens(
             ammAccount,
             account,
             amountBalance,
-            withdrawAmount,
-            withdraw2Amount,
+            amountWithdraw,
+            amount2Withdraw,
             lptAMMBalance,
-            lpTokensWithdraw,
+            tokensAdj,
             tfee,
             freezeHanding,
             withdrawAll,
@@ -861,7 +866,16 @@ AMMWithdraw::equalWithdrawLimit(
     std::uint16_t tfee)
 {
     auto frac = Number{amount} / amountBalance;
-    auto const amount2Withdraw = amount2Balance * frac;
+    auto amount2Withdraw =
+        getRoundedAsset(view.rules(), amount2Balance, frac, IsDeposit::No);
+    auto tokensAdj =
+        getRoundedLPTokens(view.rules(), lptAMMBalance, frac, IsDeposit::No);
+    if (tokensAdj == beast::zero)
+        return {tecAMM_INVALID_TOKENS, STAmount{}};
+    // factor in the adjusted tokens
+    frac = adjustFracByTokens(view.rules(), lptAMMBalance, tokensAdj, frac);
+    amount2Withdraw =
+        getRoundedAsset(view.rules(), amount2Balance, frac, IsDeposit::No);
     if (amount2Withdraw <= amount2)
     {
         return withdraw(
@@ -870,26 +884,34 @@ AMMWithdraw::equalWithdrawLimit(
             ammAccount,
             amountBalance,
             amount,
-            toSTAmount(amount2.issue(), amount2Withdraw),
+            amount2Withdraw,
             lptAMMBalance,
-            toSTAmount(lptAMMBalance.issue(), lptAMMBalance * frac),
+            tokensAdj,
             tfee);
     }
 
     frac = Number{amount2} / amount2Balance;
-    auto const amountWithdraw = amountBalance * frac;
-    XRPL_ASSERT(
-        amountWithdraw <= amount,
-        "ripple::AMMWithdraw::equalWithdrawLimit : maximum amountWithdraw");
+    auto amountWithdraw =
+        getRoundedAsset(view.rules(), amountBalance, frac, IsDeposit::No);
+    tokensAdj =
+        getRoundedLPTokens(view.rules(), lptAMMBalance, frac, IsDeposit::No);
+    if (tokensAdj == beast::zero)
+        return {tecAMM_INVALID_TOKENS, STAmount{}};  // LCOV_EXCL_LINE
+    // factor in the adjusted tokens
+    frac = adjustFracByTokens(view.rules(), lptAMMBalance, tokensAdj, frac);
+    amountWithdraw =
+        getRoundedAsset(view.rules(), amountBalance, frac, IsDeposit::No);
+    if (amountWithdraw > amount)
+        return {tecAMM_FAILED, STAmount{}};  // LCOV_EXCL_LINE
     return withdraw(
         view,
         ammSle,
         ammAccount,
         amountBalance,
-        toSTAmount(amount.issue(), amountWithdraw),
+        amountWithdraw,
         amount2,
         lptAMMBalance,
-        toSTAmount(lptAMMBalance.issue(), lptAMMBalance * frac),
+        tokensAdj,
         tfee);
 }
 
@@ -908,19 +930,29 @@ AMMWithdraw::singleWithdraw(
     STAmount const& amount,
     std::uint16_t tfee)
 {
-    auto const tokens = lpTokensOut(amountBalance, amount, lptAMMBalance, tfee);
+    auto const tokens = adjustLPTokensIn(
+        view.rules(),
+        lptAMMBalance,
+        lpTokensIn(amountBalance, amount, lptAMMBalance, tfee),
+        isWithdrawAll(ctx_.tx));
     if (tokens == beast::zero)
-        return {tecAMM_FAILED, STAmount{}};
-
+    {
+        return {tecAMM_INVALID_TOKENS, STAmount{}};
+    }
+    // factor in the adjusted tokens
+    auto const [tokensAdj, amountWithdrawAdj] = adjustAssetOutByTokens(
+        view.rules(), amountBalance, amount, lptAMMBalance, tokens, tfee);
+    if (tokensAdj == beast::zero)
+        return {tecAMM_INVALID_TOKENS, STAmount{}};  // LCOV_EXCL_LINE
     return withdraw(
         view,
         ammSle,
         ammAccount,
         amountBalance,
-        amount,
+        amountWithdrawAdj,
         std::nullopt,
         lptAMMBalance,
-        tokens,
+        tokensAdj,
         tfee);
 }
 
@@ -945,8 +977,13 @@ AMMWithdraw::singleWithdrawTokens(
     STAmount const& lpTokensWithdraw,
     std::uint16_t tfee)
 {
+    auto const tokensAdj = adjustLPTokensIn(
+        view.rules(), lptAMMBalance, lpTokensWithdraw, isWithdrawAll(ctx_.tx));
+    if (tokensAdj == beast::zero)
+        return {tecAMM_INVALID_TOKENS, STAmount{}};
+    // the adjusted tokens are factored in
     auto const amountWithdraw =
-        withdrawByTokens(amountBalance, lptAMMBalance, lpTokensWithdraw, tfee);
+        ammAssetOut(amountBalance, lptAMMBalance, tokensAdj, tfee);
     if (amount == beast::zero || amountWithdraw >= amount)
     {
         return withdraw(
@@ -957,7 +994,7 @@ AMMWithdraw::singleWithdrawTokens(
             amountWithdraw,
             std::nullopt,
             lptAMMBalance,
-            lpTokensWithdraw,
+            tokensAdj,
             tfee);
     }
 
@@ -1006,11 +1043,24 @@ AMMWithdraw::singleWithdrawEPrice(
     // t = T*(T + A*E*(f - 2))/(T*f - A*E)
     Number const ae = amountBalance * ePrice;
     auto const f = getFee(tfee);
-    auto const tokens = lptAMMBalance * (lptAMMBalance + ae * (f - 2)) /
-        (lptAMMBalance * f - ae);
-    if (tokens <= 0)
-        return {tecAMM_FAILED, STAmount{}};
-    auto const amountWithdraw = toSTAmount(amount.issue(), tokens / ePrice);
+    auto tokNoRoundCb = [&] {
+        return lptAMMBalance * (lptAMMBalance + ae * (f - 2)) /
+            (lptAMMBalance * f - ae);
+    };
+    auto tokProdCb = [&] {
+        return (lptAMMBalance + ae * (f - 2)) / (lptAMMBalance * f - ae);
+    };
+    auto const tokensAdj = getRoundedLPTokens(
+        view.rules(), tokNoRoundCb, lptAMMBalance, tokProdCb, IsDeposit::No);
+    if (tokensAdj <= beast::zero)
+    {
+        return {tecAMM_INVALID_TOKENS, STAmount{}};
+    }
+    auto amtNoRoundCb = [&] { return tokensAdj / ePrice; };
+    auto amtProdCb = [&] { return tokensAdj / ePrice; };
+    // the adjusted tokens are factored in
+    auto const amountWithdraw = getRoundedAsset(
+        view.rules(), amtNoRoundCb, amount, amtProdCb, IsDeposit::No);
     if (amount == beast::zero || amountWithdraw >= amount)
     {
         return withdraw(
@@ -1021,7 +1071,7 @@ AMMWithdraw::singleWithdrawEPrice(
             amountWithdraw,
             std::nullopt,
             lptAMMBalance,
-            toSTAmount(lptAMMBalance.issue(), tokens),
+            tokensAdj,
             tfee);
     }
 

src/xrpld/app/tx/detail/AMMWithdraw.h

@@ -301,7 +301,7 @@ private:
         std::uint16_t tfee);
 
     /** Check from the flags if it's withdraw all */
-    WithdrawAll
+    static WithdrawAll
     isWithdrawAll(STTx const& tx);
 };
 

src/xrpld/app/tx/detail/InvariantCheck.cpp

@@ -17,6 +17,9 @@
 */
 //==============================================================================
 
+#include <xrpld/app/misc/AMMHelpers.h>
+#include <xrpld/app/misc/AMMUtils.h>
+#include <xrpld/app/misc/CredentialHelpers.h>
 #include <xrpld/app/tx/detail/InvariantCheck.h>
 
 #include <xrpld/app/misc/CredentialHelpers.h>
@@ -1674,4 +1677,309 @@ ValidPermissionedDomain::finalize(
         (sleStatus_[1] ? check(*sleStatus_[1], j) : true);
 }
 
+void
+ValidAMM::visitEntry(
+    bool isDelete,
+    std::shared_ptr<SLE const> const& before,
+    std::shared_ptr<SLE const> const& after)
+{
+    if (isDelete)
+        return;
+
+    if (after)
+    {
+        auto const type = after->getType();
+        // AMM object changed
+        if (type == ltAMM)
+        {
+            ammAccount_ = after->getAccountID(sfAccount);
+            lptAMMBalanceAfter_ = after->getFieldAmount(sfLPTokenBalance);
+        }
+        // AMM pool changed
+        else if (
+            (type == ltRIPPLE_STATE && after->getFlags() & lsfAMMNode) ||
+            (type == ltACCOUNT_ROOT && after->isFieldPresent(sfAMMID)))
+        {
+            ammPoolChanged_ = true;
+        }
+    }
+
+    if (before)
+    {
+        // AMM object changed
+        if (before->getType() == ltAMM)
+        {
+            lptAMMBalanceBefore_ = before->getFieldAmount(sfLPTokenBalance);
+        }
+    }
+}
+
+static bool
+validBalances(
+    STAmount const& amount,
+    STAmount const& amount2,
+    STAmount const& lptAMMBalance,
+    ValidAMM::ZeroAllowed zeroAllowed)
+{
+    bool const positive = amount > beast::zero && amount2 > beast::zero &&
+        lptAMMBalance > beast::zero;
+    if (zeroAllowed == ValidAMM::ZeroAllowed::Yes)
+        return positive ||
+            (amount == beast::zero && amount2 == beast::zero &&
+             lptAMMBalance == beast::zero);
+    return positive;
+}
+
+bool
+ValidAMM::finalizeVote(bool enforce, beast::Journal const& j) const
+{
+    if (lptAMMBalanceAfter_ != lptAMMBalanceBefore_ || ammPoolChanged_)
+    {
+        // LPTokens and the pool can not change on vote
+        // LCOV_EXCL_START
+        JLOG(j.error()) << "AMMVote invariant failed: "
+                        << lptAMMBalanceBefore_.value_or(STAmount{}) << " "
+                        << lptAMMBalanceAfter_.value_or(STAmount{}) << " "
+                        << ammPoolChanged_;
+        if (enforce)
+            return false;
+        // LCOV_EXCL_STOP
+    }
+
+    return true;
+}
+
+bool
+ValidAMM::finalizeBid(bool enforce, beast::Journal const& j) const
+{
+    if (ammPoolChanged_)
+    {
+        // The pool can not change on bid
+        // LCOV_EXCL_START
+        JLOG(j.error()) << "AMMBid invariant failed: pool changed";
+        if (enforce)
+            return false;
+        // LCOV_EXCL_STOP
+    }
+    // LPTokens are burnt, therefore there should be fewer LPTokens
+    else if (
+        lptAMMBalanceBefore_ && lptAMMBalanceAfter_ &&
+        (*lptAMMBalanceAfter_ > *lptAMMBalanceBefore_ ||
+         *lptAMMBalanceAfter_ <= beast::zero))
+    {
+        // LCOV_EXCL_START
+        JLOG(j.error()) << "AMMBid invariant failed: " << *lptAMMBalanceBefore_
+                        << " " << *lptAMMBalanceAfter_;
+        if (enforce)
+            return false;
+        // LCOV_EXCL_STOP
+    }
+
+    return true;
+}
+
+bool
+ValidAMM::finalizeCreate(
+    STTx const& tx,
+    ReadView const& view,
+    bool enforce,
+    beast::Journal const& j) const
+{
+    if (!ammAccount_)
+    {
+        // LCOV_EXCL_START
+        JLOG(j.error())
+            << "AMMCreate invariant failed: AMM object is not created";
+        if (enforce)
+            return false;
+        // LCOV_EXCL_STOP
+    }
+    else
+    {
+        auto const [amount, amount2] = ammPoolHolds(
+            view,
+            *ammAccount_,
+            tx[sfAmount].get<Issue>(),
+            tx[sfAmount2].get<Issue>(),
+            fhIGNORE_FREEZE,
+            j);
+        // Create invariant:
+        // sqrt(amount * amount2) == LPTokens
+        // all balances are greater than zero
+        if (!validBalances(
+                amount, amount2, *lptAMMBalanceAfter_, ZeroAllowed::No) ||
+            ammLPTokens(amount, amount2, lptAMMBalanceAfter_->issue()) !=
+                *lptAMMBalanceAfter_)
+        {
+            JLOG(j.error()) << "AMMCreate invariant failed: " << amount << " "
+                            << amount2 << " " << *lptAMMBalanceAfter_;
+            if (enforce)
+                return false;
+        }
+    }
+
+    return true;
+}
+
+bool
+ValidAMM::finalizeDelete(bool enforce, TER res, beast::Journal const& j) const
+{
+    if (ammAccount_)
+    {
+        // LCOV_EXCL_START
+        std::string const msg = (res == tesSUCCESS)
+            ? "AMM object is not deleted on tesSUCCESS"
+            : "AMM object is changed on tecINCOMPLETE";
+        JLOG(j.error()) << "AMMDelete invariant failed: " << msg;
+        if (enforce)
+            return false;
+        // LCOV_EXCL_STOP
+    }
+
+    return true;
+}
+
+bool
+ValidAMM::finalizeDEX(bool enforce, beast::Journal const& j) const
+{
+    if (ammAccount_)
+    {
+        // LCOV_EXCL_START
+        JLOG(j.error()) << "AMM swap invariant failed: AMM object changed";
+        if (enforce)
+            return false;
+        // LCOV_EXCL_STOP
+    }
+
+    return true;
+}
+
+bool
+ValidAMM::generalInvariant(
+    ripple::STTx const& tx,
+    ripple::ReadView const& view,
+    ZeroAllowed zeroAllowed,
+    beast::Journal const& j) const
+{
+    auto const [amount, amount2] = ammPoolHolds(
+        view,
+        *ammAccount_,
+        tx[sfAsset].get<Issue>(),
+        tx[sfAsset2].get<Issue>(),
+        fhIGNORE_FREEZE,
+        j);
+    // Deposit and Withdrawal invariant:
+    // sqrt(amount * amount2) >= LPTokens
+    // all balances are greater than zero
+    // unless on last withdrawal
+    auto const poolProductMean = root2(amount * amount2);
+    bool const nonNegativeBalances =
+        validBalances(amount, amount2, *lptAMMBalanceAfter_, zeroAllowed);
+    bool const strongInvariantCheck = poolProductMean >= *lptAMMBalanceAfter_;
+    // Allow for a small relative error if strongInvariantCheck fails
+    auto weakInvariantCheck = [&]() {
+        return *lptAMMBalanceAfter_ != beast::zero &&
+            withinRelativeDistance(
+                poolProductMean, Number{*lptAMMBalanceAfter_}, Number{1, -11});
+    };
+    if (!nonNegativeBalances ||
+        (!strongInvariantCheck && !weakInvariantCheck()))
+    {
+        JLOG(j.error()) << "AMM " << tx.getTxnType() << " invariant failed: "
+                        << tx.getHash(HashPrefix::transactionID) << " "
+                        << ammPoolChanged_ << " " << amount << " " << amount2
+                        << " " << poolProductMean << " "
+                        << lptAMMBalanceAfter_->getText() << " "
+                        << ((*lptAMMBalanceAfter_ == beast::zero)
+                                ? Number{1}
+                                : ((*lptAMMBalanceAfter_ - poolProductMean) /
+                                   poolProductMean));
+        return false;
+    }
+
+    return true;
+}
+
+bool
+ValidAMM::finalizeDeposit(
+    ripple::STTx const& tx,
+    ripple::ReadView const& view,
+    bool enforce,
+    beast::Journal const& j) const
+{
+    if (!ammAccount_)
+    {
+        // LCOV_EXCL_START
+        JLOG(j.error()) << "AMMDeposit invariant failed: AMM object is deleted";
+        if (enforce)
+            return false;
+        // LCOV_EXCL_STOP
+    }
+    else if (!generalInvariant(tx, view, ZeroAllowed::No, j) && enforce)
+        return false;
+
+    return true;
+}
+
+bool
+ValidAMM::finalizeWithdraw(
+    ripple::STTx const& tx,
+    ripple::ReadView const& view,
+    bool enforce,
+    beast::Journal const& j) const
+{
+    if (!ammAccount_)
+    {
+        // Last Withdraw or Clawback deleted AMM
+    }
+    else if (!generalInvariant(tx, view, ZeroAllowed::Yes, j))
+    {
+        if (enforce)
+            return false;
+    }
+
+    return true;
+}
+
+bool
+ValidAMM::finalize(
+    STTx const& tx,
+    TER const result,
+    XRPAmount const,
+    ReadView const& view,
+    beast::Journal const& j)
+{
+    // Delete may return tecINCOMPLETE if there are too many
+    // trustlines to delete.
+    if (result != tesSUCCESS && result != tecINCOMPLETE)
+        return true;
+
+    bool const enforce = true;  // view.rules().enabled(fixAMMv1_3);
+
+    switch (tx.getTxnType())
+    {
+        case ttAMM_CREATE:
+            return finalizeCreate(tx, view, enforce, j);
+        case ttAMM_DEPOSIT:
+            return finalizeDeposit(tx, view, enforce, j);
+        case ttAMM_CLAWBACK:
+        case ttAMM_WITHDRAW:
+            return finalizeWithdraw(tx, view, enforce, j);
+        case ttAMM_BID:
+            return finalizeBid(enforce, j);
+        case ttAMM_VOTE:
+            return finalizeVote(enforce, j);
+        case ttAMM_DELETE:
+            return finalizeDelete(enforce, result, j);
+        case ttCHECK_CASH:
+        case ttOFFER_CREATE:
+        case ttPAYMENT:
+            return finalizeDEX(enforce, j);
+        default:
+            break;
+    }
+
+    return true;
+}
+
 }  // namespace ripple

src/xrpld/app/tx/detail/InvariantCheck.h

@@ -617,6 +617,69 @@ public:
         beast::Journal const&);
 };
 
+class ValidAMM
+{
+    std::optional<AccountID> ammAccount_;
+    std::optional<STAmount> lptAMMBalanceAfter_;
+    std::optional<STAmount> lptAMMBalanceBefore_;
+    bool ammPoolChanged_;
+
+public:
+    enum class ZeroAllowed : bool { No = false, Yes = true };
+
+    ValidAMM() : ammPoolChanged_{false}
+    {
+    }
+    void
+    visitEntry(
+        bool,
+        std::shared_ptr<SLE const> const&,
+        std::shared_ptr<SLE const> const&);
+
+    bool
+    finalize(
+        STTx const&,
+        TER const,
+        XRPAmount const,
+        ReadView const&,
+        beast::Journal const&);
+
+private:
+    bool
+    finalizeBid(bool enforce, beast::Journal const&) const;
+    bool
+    finalizeVote(bool enforce, beast::Journal const&) const;
+    bool
+    finalizeCreate(
+        STTx const&,
+        ReadView const&,
+        bool enforce,
+        beast::Journal const&) const;
+    bool
+    finalizeDelete(bool enforce, TER res, beast::Journal const&) const;
+    bool
+    finalizeDeposit(
+        STTx const&,
+        ReadView const&,
+        bool enforce,
+        beast::Journal const&) const;
+    // Includes clawback
+    bool
+    finalizeWithdraw(
+        STTx const&,
+        ReadView const&,
+        bool enforce,
+        beast::Journal const&) const;
+    bool
+    finalizeDEX(bool enforce, beast::Journal const&) const;
+    bool
+    generalInvariant(
+        STTx const&,
+        ReadView const&,
+        ZeroAllowed zeroAllowed,
+        beast::Journal const&) const;
+};
+
 // additional invariant checks can be declared above and then added to this
 // tuple
 using InvariantChecks = std::tuple<
@@ -636,7 +699,8 @@ using InvariantChecks = std::tuple<
     NFTokenCountTracking,
     ValidClawback,
     ValidMPTIssuance,
-    ValidPermissionedDomain>;
+    ValidPermissionedDomain,
+    ValidAMM>;
 
 /**
  * @brief get a tuple of all invariant checks

src/xrpld/app/tx/detail/Offer.h

@@ -21,6 +21,8 @@
 #define RIPPLE_APP_BOOK_OFFER_H_INCLUDED
 
 #include <xrpld/ledger/View.h>
+
+#include <xrpl/basics/Log.h>
 #include <xrpl/basics/contract.h>
 #include <xrpl/protocol/Quality.h>
 #include <xrpl/protocol/Rules.h>
@@ -169,8 +171,21 @@ public:
      * always returns true.
      */
     bool
-    checkInvariant(TAmounts<TIn, TOut> const&, beast::Journal j) const
+    checkInvariant(TAmounts<TIn, TOut> const& consumed, beast::Journal j) const
     {
+        if (consumed.in > m_amounts.in || consumed.out > m_amounts.out)
+        {
+            // LCOV_EXCL_START
+            JLOG(j.error())
+                << "AMMOffer::checkInvariant failed: consumed "
+                << to_string(consumed.in) << " " << to_string(consumed.out)
+                << " amounts " << to_string(m_amounts.in) << " "
+                << to_string(m_amounts.out);
+
+            return false;
+            // LCOV_EXCL_STOP
+        }
+
         return true;
     }
 };