add "trade modified" warning if items are removed/reduced, configurable

Add config for requiring second confirmation screen, enabled by default
More resilience to adding items to trade after moving to confirmation screen

README.md

@@ -12,6 +12,7 @@ Players can request a trade, review both offers in a shared GUI, accept once to
 - Shared trade screen with separate offer areas for both players
 - Two-step confirmation flow
 - Quantity-based item selection with quick amounts and `Trade X`
+- Warning if items are removed/modified
 - Inventory-safe finalization: nothing changes until safety and security checks pass and the trade succeeds
 - Configurable trade safety checks to prevent dangerous mid-combat or mid-movement trading
 - Per-player trade toggles and ignore list support
@@ -49,6 +50,12 @@ They can also respond manually:
 - Once both players accept, the screen enters the confirmation stage
 - Click `Confirm` to finalize
 
+If a player reduces or removes items from an offer:
+
+- any pending accepts / confirms are invalidated
+- the changed offer slot gets a blinking red border and `!`
+- the trade window shows a red `Trade Modified` warning
+
 ## Commands
 
 ### Player commands
@@ -109,6 +116,7 @@ The trade verifies:
 - both players are still within configured trade distance, if enabled
 - both live inventories still match the snapshots taken when the trade started
 - both players can receive the incoming items
+- both players have re-accepted after any offer changes
 
 If any check fails, the trade is cancelled and both players receive an explicit chat message explaining why.
 
@@ -133,6 +141,16 @@ Server config values live under the `trade` section.
   - default: `false`
   - enables debug commands and debug UI/testing tools
 
+### Trade flow
+
+- `requireSecondConfirmation`
+  - default: `true`
+  - requires the second confirm step after both players accept the offer
+
+- `showTradeModifiedWarnings`
+  - default: `true`
+  - shows the `Trade Modified` warning and changed-slot highlights when offers are reduced or removed
+
 ### Safety
 
 - `requireOnGround`
@@ -196,4 +214,4 @@ Debug tools are disabled by default and only available when:
 
 - `enableDebugFeatures = true`
 
-When enabled, the mod exposes `/trade debug ...` commands and on-screen debug controls for single-client testing.
+When enabled, the mod exposes `/trade debug ...` commands and on-screen debug controls for single-client testing.

src/main/java/com/trunksbomb/trade/client/TradeScreen.java

@@ -37,8 +37,9 @@ public class TradeScreen extends AbstractContainerScreen<TradeScreen.TradeMenu>
     private static final int BANNER_X = 58;
     private static final int BANNER_Y = 6;
     private static final int CENTER_COLUMN_X = 115;
-    private static final int STATUS_LABEL_Y = 54;
+    private static final int MODIFIED_LABEL_Y = 17;
-    private static final int CONFIRM_LABEL_Y = 34;
+    private static final int STATUS_LABEL_Y = 51;
+    private static final int CONFIRM_LABEL_Y = 26;
     private static final int ACCEPT_BUTTON_Y = 74;
     private static final int CANCEL_BUTTON_Y = 98;
     private static final int ACTION_BUTTON_WIDTH = 48;
@@ -218,6 +219,9 @@ public class TradeScreen extends AbstractContainerScreen<TradeScreen.TradeMenu>
     protected void renderLabels(GuiGraphics guiGraphics, int mouseX, int mouseY) {
         guiGraphics.drawString(font, "Trading with " + menu.view().otherName(), titleLabelX, titleLabelY, 0x404040, false);
         guiGraphics.drawString(font, playerInventoryTitle, inventoryLabelX, inventoryLabelY, 0x404040, false);
+        if (menu.view().itemsChanged()) {
+            drawScaledCenteredColumnText(guiGraphics, "Trade Modified", MODIFIED_LABEL_Y, 0xB02020, 0.7F);
+        }
         if (menu.view().stage() == TradeStage.CONFIRMING) {
             drawScaledCenteredColumnText(guiGraphics, "Are you", CONFIRM_LABEL_Y, 0xB02020, 0.7F);
             drawScaledCenteredColumnText(guiGraphics, "sure you want", CONFIRM_LABEL_Y + 7, 0xB02020, 0.7F);
@@ -245,6 +249,7 @@ public class TradeScreen extends AbstractContainerScreen<TradeScreen.TradeMenu>
             acceptButton.setMessage(acceptButtonLabel());
         }
         super.render(guiGraphics, mouseX, mouseY, partialTick);
+        renderChangedSlotWarnings(guiGraphics);
         renderContextMenu(guiGraphics, mouseX, mouseY);
         renderAmountPrompt(guiGraphics);
         renderTooltip(guiGraphics, mouseX, mouseY);
@@ -254,6 +259,36 @@ public class TradeScreen extends AbstractContainerScreen<TradeScreen.TradeMenu>
         return Component.literal(menu.view().stage() == TradeStage.CONFIRMING ? "Confirm" : "Accept");
     }
 
+    private void renderChangedSlotWarnings(GuiGraphics guiGraphics) {
+        if (!menu.view().itemsChanged()) {
+            return;
+        }
+
+        boolean blinkOn = ((System.currentTimeMillis() / 300L) & 1L) == 0L;
+        int color = blinkOn ? 0xFFFF4040 : 0xFF7A1010;
+        for (Slot slot : menu.slots) {
+            if (slot instanceof SelfOfferSlot selfOfferSlot) {
+                if (menu.view().selfChangedSlots().get(selfOfferSlot.offerIndex())) {
+                    renderChangedSlotWarning(guiGraphics, slot, color);
+                }
+            } else if (slot instanceof OtherOfferSlot otherOfferSlot) {
+                if (menu.view().otherChangedSlots().get(otherOfferSlot.offerIndex())) {
+                    renderChangedSlotWarning(guiGraphics, slot, color);
+                }
+            }
+        }
+    }
+
+    private void renderChangedSlotWarning(GuiGraphics guiGraphics, Slot slot, int color) {
+        int x = leftPos + slot.x;
+        int y = topPos + slot.y;
+        guiGraphics.fill(x - 1, y - 1, x + 17, y, color);
+        guiGraphics.fill(x - 1, y + 16, x + 17, y + 17, color);
+        guiGraphics.fill(x - 1, y, x, y + 16, color);
+        guiGraphics.fill(x + 16, y, x + 17, y + 16, color);
+        guiGraphics.drawString(font, "!", x + 11, y - 2, color, false);
+    }
+
     private void sendAction(TradeAction action, int slot, int amount) {
         if (minecraft == null || minecraft.getConnection() == null) {
             return;
@@ -575,6 +610,10 @@ public class TradeScreen extends AbstractContainerScreen<TradeScreen.TradeMenu>
             super(container, slot, x, y);
         }
 
+        public int offerIndex() {
+            return getSlotIndex();
+        }
+
         @Override
         public boolean mayPickup(Player player) {
             return false;

src/main/java/com/trunksbomb/trade/command/TradeCommand.java

@@ -260,7 +260,7 @@ public final class TradeCommand {
 
         try {
             if (!TradeManager.get(source.getServer()).setDebugOffer(player, DebugTradeSession.parseOfferSpec(spec))) {
-                source.sendFailure(Component.literal("Start a debug trade first with /trade debug init."));
+                source.sendFailure(Component.literal("Start a debug trade first with /trade debug init, and only change offers before confirmation."));
                 return 0;
             }
         } catch (IllegalArgumentException exception) {
@@ -285,6 +285,10 @@ public final class TradeCommand {
         try {
             int result = TradeManager.get(source.getServer()).removeDebugOffer(player, spec);
             if (result < 0) {
+                if (result == -2) {
+                    source.sendFailure(Component.literal("Trade offers cannot be changed during confirmation."));
+                    return 0;
+                }
                 source.sendFailure(Component.literal("Start a debug trade first with /trade debug init."));
                 return 0;
             }

src/main/java/com/trunksbomb/trade/mod/TradeConfig.java

@@ -7,6 +7,8 @@ public final class TradeConfig {
     private static final ModConfigSpec.IntValue TRADE_COMMAND_PROXIMITY;
     private static final ModConfigSpec.IntValue REQUEST_TIMEOUT_SECONDS;
     private static final ModConfigSpec.BooleanValue ENABLE_DEBUG_FEATURES;
+    private static final ModConfigSpec.BooleanValue REQUIRE_SECOND_CONFIRMATION;
+    private static final ModConfigSpec.BooleanValue SHOW_TRADE_MODIFIED_WARNINGS;
     private static final ModConfigSpec.BooleanValue REQUIRE_ON_GROUND;
     private static final ModConfigSpec.BooleanValue REQUIRE_STATIONARY;
     private static final ModConfigSpec.DoubleValue STATIONARY_SPEED_THRESHOLD;
@@ -30,6 +32,10 @@ public final class TradeConfig {
                 .defineInRange("requestTimeoutSeconds", 30, 1, 3600);
         ENABLE_DEBUG_FEATURES = builder.comment("Enable debug trade commands and debug UI/testing tools.")
                 .define("enableDebugFeatures", false);
+        REQUIRE_SECOND_CONFIRMATION = builder.comment("Require a second confirmation step after both players accept the initial offer.")
+                .define("requireSecondConfirmation", true);
+        SHOW_TRADE_MODIFIED_WARNINGS = builder.comment("Show Trade Modified warnings and changed-slot highlights when offers are reduced or removed.")
+                .define("showTradeModifiedWarnings", true);
         REQUIRE_ON_GROUND = builder.comment("Require players to be on solid ground before requesting or accepting a trade.")
                 .define("requireOnGround", true);
         REQUIRE_STATIONARY = builder.comment("Require players to be stationary before requesting or accepting a trade.")
@@ -78,6 +84,14 @@ public final class TradeConfig {
         }
     }
 
+    public static boolean requireSecondConfirmation() {
+        return REQUIRE_SECOND_CONFIRMATION.get();
+    }
+
+    public static boolean showTradeModifiedWarnings() {
+        return SHOW_TRADE_MODIFIED_WARNINGS.get();
+    }
+
     public static boolean requireOnGround() {
         return REQUIRE_ON_GROUND.get();
     }

src/main/java/com/trunksbomb/trade/trade/DebugTradeSession.java

@@ -2,6 +2,7 @@ package com.trunksbomb.trade.trade;
 
 import com.trunksbomb.trade.network.TradeClosePayload;
 import com.trunksbomb.trade.network.TradeStatePayload;
+import com.trunksbomb.trade.mod.TradeConfig;
 import java.util.ArrayList;
 import java.util.EnumSet;
 import java.util.List;
@@ -26,6 +27,8 @@ public class DebugTradeSession {
     private final List<ItemStack> inventorySnapshot;
     private final List<TradeEntry> selfOffer = blankOffer();
     private final List<ItemStack> otherOffer = blankStacks();
+    private final List<Boolean> selfChangedSlots = blankChangedSlots();
+    private final List<Boolean> otherChangedSlots = blankChangedSlots();
     private final EnumSet<DebugUnsafeState> unsafeStates = EnumSet.noneOf(DebugUnsafeState.class);
     private boolean selfAccepted;
     private boolean otherAccepted;
@@ -90,7 +93,7 @@ public class DebugTradeSession {
                 ItemStack merged = entry.stack().copy();
                 merged.grow(moveAmount);
                 selfOffer.set(i, new TradeEntry(inventorySlot, merged));
-                clearAccepts();
+                clearAccepts(false, false, -1);
                 return true;
             }
         }
@@ -101,7 +104,7 @@ public class DebugTradeSession {
         }
 
         selfOffer.set(freeSlot, new TradeEntry(inventorySlot, sourceStack.copyWithCount(moveAmount)));
-        clearAccepts();
+        clearAccepts(false, false, -1);
         return true;
     }
 
@@ -124,7 +127,7 @@ public class DebugTradeSession {
             selfOffer.set(offerSlot, null);
         }
 
-        clearAccepts();
+        clearAccepts(true, false, offerSlot);
         return true;
     }
 
@@ -140,7 +143,7 @@ public class DebugTradeSession {
         for (int i = 0; i < OFFER_SLOT_COUNT; i++) {
             otherOffer.set(i, i < offer.size() ? offer.get(i).copy() : ItemStack.EMPTY);
         }
-        clearAccepts();
+        clearAccepts(false, false, -1);
     }
 
     public boolean appendOtherOffer(List<ItemStack> offer) {
@@ -156,18 +159,25 @@ public class DebugTradeSession {
         }
 
         if (changed) {
-            clearAccepts();
+            clearAccepts(false, false, -1);
         }
         return changed;
     }
 
     public boolean removeOtherOffer(String spec) {
         if ("all".equalsIgnoreCase(spec)) {
+            boolean changed = false;
             for (int i = 0; i < OFFER_SLOT_COUNT; i++) {
+                if (!otherOffer.get(i).isEmpty()) {
+                    otherChangedSlots.set(i, true);
+                    changed = true;
+                }
                 otherOffer.set(i, ItemStack.EMPTY);
             }
-            clearAccepts();
+            if (changed) {
-            return true;
+                clearAccepts(false, false, -1);
+            }
+            return changed;
         }
 
         int split = spec.indexOf(':');
@@ -194,7 +204,7 @@ public class DebugTradeSession {
             otherOffer.set(slot, updated);
         }
 
-        clearAccepts();
+        clearAccepts(false, true, slot);
         return true;
     }
 
@@ -204,7 +214,7 @@ public class DebugTradeSession {
                 continue;
             }
             otherOffer.set(i, ItemStack.EMPTY);
-            clearAccepts();
+            clearAccepts(false, true, i);
             return true;
         }
         return false;
@@ -263,6 +273,7 @@ public class DebugTradeSession {
     }
 
     public TradeView view() {
+        boolean showModifiedWarnings = TradeConfig.showTradeModifiedWarnings();
         return new TradeView(
                 id,
                 player.getGameProfile().getName(),
@@ -271,10 +282,13 @@ public class DebugTradeSession {
                 stage,
                 selfAccepted,
                 otherAccepted,
+                showModifiedWarnings && hasChangedSlots(),
                 inventoryDisplay(),
                 emptyReservedSnapshot(),
                 selfOfferSnapshot(),
-                otherOfferSnapshot());
+                otherOfferSnapshot(),
+                showModifiedWarnings ? changedSlotSnapshot(selfChangedSlots) : blankChangedSlots(),
+                showModifiedWarnings ? changedSlotSnapshot(otherChangedSlots) : blankChangedSlots());
     }
 
     public static List<ItemStack> parseOfferSpec(String spec) {
@@ -418,9 +432,26 @@ public class DebugTradeSession {
         return count;
     }
 
-    private void clearAccepts() {
+    private void clearAccepts(boolean markSelfChanged, boolean markOtherChanged, int changedSlot) {
         selfAccepted = false;
         otherAccepted = false;
+        if (changedSlot >= 0) {
+            if (markSelfChanged) {
+                selfChangedSlots.set(changedSlot, true);
+            }
+            if (markOtherChanged) {
+                otherChangedSlots.set(changedSlot, true);
+            }
+        }
+    }
+
+    private boolean hasChangedSlots() {
+        for (int i = 0; i < OFFER_SLOT_COUNT; i++) {
+            if (selfChangedSlots.get(i) || otherChangedSlots.get(i)) {
+                return true;
+            }
+        }
+        return false;
     }
 
     private List<ItemStack> inventorySnapshotCopy() {
@@ -459,6 +490,18 @@ public class DebugTradeSession {
         return result;
     }
 
+    private static List<Boolean> blankChangedSlots() {
+        List<Boolean> result = new ArrayList<>(OFFER_SLOT_COUNT);
+        for (int i = 0; i < OFFER_SLOT_COUNT; i++) {
+            result.add(false);
+        }
+        return result;
+    }
+
+    private static List<Boolean> changedSlotSnapshot(List<Boolean> changedSlots) {
+        return new ArrayList<>(changedSlots);
+    }
+
     private static List<ItemStack> inventorySnapshot(ServerPlayer player) {
         List<ItemStack> result = new ArrayList<>(INVENTORY_SLOT_COUNT);
         Inventory inventory = player.getInventory();

src/main/java/com/trunksbomb/trade/trade/TradeManager.java

@@ -233,15 +233,17 @@ public class TradeManager {
             return;
         }
 
-        if (!session.isConfirmationStage()) {
+        if (!session.bothAccepted()) {
-            session.advanceToConfirmation();
             session.syncToPlayers();
             return;
         }
 
-        if (!session.bothAccepted()) {
+        if (!session.isConfirmationStage()) {
-            session.syncToPlayers();
+            if (TradeConfig.requireSecondConfirmation()) {
-            return;
+                session.advanceToConfirmation();
+                session.syncToPlayers();
+                return;
+            }
         }
 
         TradeSession.CompletionResult completion = session.completeTrade();
@@ -278,15 +280,17 @@ public class TradeManager {
             return;
         }
 
-        if (!session.isConfirmationStage()) {
+        if (!session.bothAccepted()) {
-            session.advanceToConfirmation();
             session.sync();
             return;
         }
 
-        if (!session.bothAccepted()) {
+        if (!session.isConfirmationStage()) {
-            session.sync();
+            if (TradeConfig.requireSecondConfirmation()) {
-            return;
+                session.advanceToConfirmation();
+                session.sync();
+                return;
+            }
         }
 
         if (session.completeTrade()) {
@@ -404,7 +408,7 @@ public class TradeManager {
             return false;
         }
         DebugTradeSession session = getDebugSession(player);
-        if (session == null) {
+        if (session == null || session.isConfirmationStage()) {
             return false;
         }
 
@@ -421,6 +425,9 @@ public class TradeManager {
         if (session == null) {
             return -1;
         }
+        if (session.isConfirmationStage()) {
+            return -2;
+        }
 
         boolean changed = session.removeOtherOffer(spec);
         if (changed) {
@@ -447,20 +454,25 @@ public class TradeManager {
         }
 
         session.acceptOther();
-        if (!session.isConfirmationStage()) {
+        if (!session.bothAccepted()) {
-            session.advanceToConfirmation();
             session.sync();
             return true;
         }
 
+        if (!session.isConfirmationStage()) {
+            if (TradeConfig.requireSecondConfirmation()) {
+                session.advanceToConfirmation();
+                session.sync();
+                return true;
+            }
+        }
+
         if (session.bothAccepted()) {
             if (session.completeTrade()) {
                 finishDebug(session, Component.literal("Debug trade completed."));
             } else {
                 closeDebug(session, Component.literal("Debug trade cancelled because the items would not fit."));
             }
-        } else {
-            session.sync();
         }
         return true;
     }
@@ -531,20 +543,36 @@ public class TradeManager {
         try {
             switch (action) {
                 case SET_OFFER -> {
+                    if (session.isConfirmationStage()) {
+                        player.sendSystemMessage(Component.literal("Trade offers cannot be changed during confirmation."));
+                        return;
+                    }
                     session.setOtherOffer(DebugTradeSession.parseOfferSpec(spec));
                     session.sync();
                 }
                 case APPEND_RANDOM -> {
+                    if (session.isConfirmationStage()) {
+                        player.sendSystemMessage(Component.literal("Trade offers cannot be changed during confirmation."));
+                        return;
+                    }
                     if (session.appendOtherOffer(DebugTradeSession.randomSingleStackOffer())) {
                         session.sync();
                     }
                 }
                 case REMOVE_OFFER -> {
+                    if (session.isConfirmationStage()) {
+                        player.sendSystemMessage(Component.literal("Trade offers cannot be changed during confirmation."));
+                        return;
+                    }
                     if (session.removeOtherOffer(spec)) {
                         session.sync();
                     }
                 }
                 case REMOVE_LAST -> {
+                    if (session.isConfirmationStage()) {
+                        player.sendSystemMessage(Component.literal("Trade offers cannot be changed during confirmation."));
+                        return;
+                    }
                     if (session.removeLastOtherOffer()) {
                         session.sync();
                     }

src/main/java/com/trunksbomb/trade/trade/TradeSession.java

@@ -1,5 +1,6 @@
 package com.trunksbomb.trade.trade;
 
+import com.trunksbomb.trade.mod.TradeConfig;
 import com.trunksbomb.trade.network.TradeClosePayload;
 import com.trunksbomb.trade.network.TradeStatePayload;
 import java.util.ArrayList;
@@ -10,7 +11,6 @@ import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.entity.player.Inventory;
 import net.minecraft.world.item.ItemStack;
 import net.neoforged.neoforge.network.PacketDistributor;
-import com.trunksbomb.trade.mod.TradeConfig;
 
 public class TradeSession {
     private static final int INVENTORY_SLOT_COUNT = TradeView.INVENTORY_SLOT_COUNT;
@@ -23,6 +23,8 @@ public class TradeSession {
     private final List<ItemStack> secondInventory;
     private final List<TradeEntry> firstOffer = blankOffer();
     private final List<TradeEntry> secondOffer = blankOffer();
+    private final List<Boolean> firstChangedSlots = blankChangedSlots();
+    private final List<Boolean> secondChangedSlots = blankChangedSlots();
     private boolean firstAccepted;
     private boolean secondAccepted;
     private TradeStage stage = TradeStage.OFFERING;
@@ -95,7 +97,7 @@ public class TradeSession {
                 ItemStack merged = entry.stack().copy();
                 merged.grow(moveAmount);
                 offer.set(i, new TradeEntry(inventorySlot, merged));
-                clearAccepts();
+                clearAccepts(false, false, -1);
                 return true;
             }
         }
@@ -106,7 +108,7 @@ public class TradeSession {
         }
 
         offer.set(freeSlot, new TradeEntry(inventorySlot, sourceStack.copyWithCount(moveAmount)));
-        clearAccepts();
+        clearAccepts(false, false, -1);
         return true;
     }
 
@@ -130,7 +132,7 @@ public class TradeSession {
             offer.set(offerSlot, null);
         }
 
-        clearAccepts();
+        clearAccepts(player == first, player == second, offerSlot);
         return true;
     }
 
@@ -193,6 +195,7 @@ public class TradeSession {
     public TradeView viewFor(ServerPlayer player) {
         boolean isFirst = player == first;
         ServerPlayer other = isFirst ? second : first;
+        boolean showModifiedWarnings = TradeConfig.showTradeModifiedWarnings();
         return new TradeView(
                 id,
                 player.getGameProfile().getName(),
@@ -201,10 +204,13 @@ public class TradeSession {
                 stage,
                 isFirst ? firstAccepted : secondAccepted,
                 isFirst ? secondAccepted : firstAccepted,
+                showModifiedWarnings && hasChangedSlots(),
                 inventoryDisplayFor(player),
                 emptyReservedSnapshot(),
                 offerSnapshot(isFirst ? firstOffer : secondOffer),
-                offerSnapshot(isFirst ? secondOffer : firstOffer));
+                offerSnapshot(isFirst ? secondOffer : firstOffer),
+                showModifiedWarnings ? changedSlotSnapshot(isFirst ? firstChangedSlots : secondChangedSlots) : blankChangedSlots(),
+                showModifiedWarnings ? changedSlotSnapshot(isFirst ? secondChangedSlots : firstChangedSlots) : blankChangedSlots());
     }
 
     public void sendState(ServerPlayer player) {
@@ -318,9 +324,26 @@ public class TradeSession {
         return -1;
     }
 
-    private void clearAccepts() {
+    private void clearAccepts(boolean markFirstChanged, boolean markSecondChanged, int changedSlot) {
         firstAccepted = false;
         secondAccepted = false;
+        if (changedSlot >= 0) {
+            if (markFirstChanged) {
+                firstChangedSlots.set(changedSlot, true);
+            }
+            if (markSecondChanged) {
+                secondChangedSlots.set(changedSlot, true);
+            }
+        }
+    }
+
+    private boolean hasChangedSlots() {
+        for (int i = 0; i < OFFER_SLOT_COUNT; i++) {
+            if (firstChangedSlots.get(i) || secondChangedSlots.get(i)) {
+                return true;
+            }
+        }
+        return false;
     }
 
     private int reservedCount(ServerPlayer player, int inventorySlot) {
@@ -377,6 +400,18 @@ public class TradeSession {
         return result;
     }
 
+    private static List<Boolean> blankChangedSlots() {
+        List<Boolean> result = new ArrayList<>(OFFER_SLOT_COUNT);
+        for (int i = 0; i < OFFER_SLOT_COUNT; i++) {
+            result.add(false);
+        }
+        return result;
+    }
+
+    private static List<Boolean> changedSlotSnapshot(List<Boolean> changedSlots) {
+        return new ArrayList<>(changedSlots);
+    }
+
     private static List<ItemStack> inventorySnapshot(ServerPlayer player) {
         List<ItemStack> result = new ArrayList<>(INVENTORY_SLOT_COUNT);
         Inventory inventory = player.getInventory();

src/main/java/com/trunksbomb/trade/trade/TradeView.java

@@ -15,10 +15,13 @@ public record TradeView(
         TradeStage stage,
         boolean selfAccepted,
         boolean otherAccepted,
+        boolean itemsChanged,
         List<ItemStack> inventory,
         List<Integer> reservedCounts,
         List<ItemStack> selfOffer,
-        List<ItemStack> otherOffer) {
+        List<ItemStack> otherOffer,
+        List<Boolean> selfChangedSlots,
+        List<Boolean> otherChangedSlots) {
 
     public static final int INVENTORY_SLOT_COUNT = 36;
     public static final int OFFER_SLOT_COUNT = 36;
@@ -33,10 +36,13 @@ public record TradeView(
             buf.writeEnum(value.stage);
             buf.writeBoolean(value.selfAccepted);
             buf.writeBoolean(value.otherAccepted);
+            buf.writeBoolean(value.itemsChanged);
             writeStacks(buf, value.inventory, INVENTORY_SLOT_COUNT);
             writeInts(buf, value.reservedCounts, INVENTORY_SLOT_COUNT);
             writeStacks(buf, value.selfOffer, OFFER_SLOT_COUNT);
             writeStacks(buf, value.otherOffer, OFFER_SLOT_COUNT);
+            writeBooleans(buf, value.selfChangedSlots, OFFER_SLOT_COUNT);
+            writeBooleans(buf, value.otherChangedSlots, OFFER_SLOT_COUNT);
         }
 
         @Override
@@ -49,10 +55,13 @@ public record TradeView(
                     buf.readEnum(TradeStage.class),
                     buf.readBoolean(),
                     buf.readBoolean(),
+                    buf.readBoolean(),
                     readStacks(buf, INVENTORY_SLOT_COUNT),
                     readInts(buf, INVENTORY_SLOT_COUNT),
                     readStacks(buf, OFFER_SLOT_COUNT),
-                    readStacks(buf, OFFER_SLOT_COUNT));
+                    readStacks(buf, OFFER_SLOT_COUNT),
+                    readBooleans(buf, OFFER_SLOT_COUNT),
+                    readBooleans(buf, OFFER_SLOT_COUNT));
         }
     };
 
@@ -83,4 +92,18 @@ public record TradeView(
         }
         return values;
     }
+
+    private static void writeBooleans(RegistryFriendlyByteBuf buf, List<Boolean> values, int expectedSize) {
+        for (int i = 0; i < expectedSize; i++) {
+            buf.writeBoolean(values.get(i));
+        }
+    }
+
+    private static List<Boolean> readBooleans(RegistryFriendlyByteBuf buf, int expectedSize) {
+        List<Boolean> values = new ArrayList<>(expectedSize);
+        for (int i = 0; i < expectedSize; i++) {
+            values.add(buf.readBoolean());
+        }
+        return values;
+    }
 }