Fix PR 3 review findings [skip ci]

integrations/minecraft/src/main/java/net/scopenet/minecraft/Bridge.java

@@ -4,6 +4,7 @@ import net.scopenet.integration.*;
 import net.minecraft.server.MinecraftServer;
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.network.chat.Component;
+import net.minecraft.core.BlockPos;
 import java.net.*;
 import java.nio.file.Path;
 import java.util.*;
@@ -72,6 +73,18 @@ public final class Bridge {
         if (current != null) current.activity.action(player.getUUID(), player.getName().getString(), action, amount);
     }
 
+    /** Fail closed while a claim lookup is pending or the panel is unavailable. */
+    public static boolean canModify(ServerPlayer player, BlockPos pos) {
+        Integration current = integration;
+        if (current == null) return false;
+        if (!current.settings().guildsEnabled() || !current.settings().landClaimingEnabled()) return true;
+        String dimension = player.serverLevel().dimension().location().toString();
+        ChunkCheckResult check = current.checkChunk(dimension, pos.getX() >> 4, pos.getZ() >> 4, player.getUUID());
+        if (check.allowed()) return true;
+        player.displayClientMessage(Component.literal("This chunk is protected by a guild or the claim check is unavailable."), true);
+        return false;
+    }
+
     public static void command(ServerPlayer player, String command) {
         String name = command.strip().split("\\s+", 2)[0];
         Integration current = integration;

integrations/minecraft/src/main/java/net/scopenet/minecraft/mixin/BlockBreakMixin.java

@@ -0,0 +1,20 @@
+package net.scopenet.minecraft.mixin;
+
+import net.minecraft.core.BlockPos;
+import net.minecraft.server.level.ServerPlayerGameMode;
+import net.scopenet.minecraft.Bridge;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
+
+@Mixin(ServerPlayerGameMode.class)
+public abstract class BlockBreakMixin {
+    @Shadow protected net.minecraft.server.level.ServerPlayer player;
+
+    @Inject(method = "destroyBlock", at = @At("HEAD"), cancellable = true)
+    private void scopenet$protectBreak(BlockPos pos, CallbackInfoReturnable<Boolean> cir) {
+        if (!Bridge.canModify(player, pos)) cir.setReturnValue(false);
+    }
+}

integrations/minecraft/src/main/java/net/scopenet/minecraft/mixin/BlockInteractMixin.java

@@ -0,0 +1,26 @@
+package net.scopenet.minecraft.mixin;
+
+import net.minecraft.server.level.ServerPlayer;
+import net.minecraft.server.level.ServerPlayerGameMode;
+import net.minecraft.world.InteractionHand;
+import net.minecraft.world.InteractionResult;
+import net.minecraft.world.item.ItemStack;
+import net.minecraft.world.level.Level;
+import net.minecraft.world.phys.BlockHitResult;
+import net.scopenet.minecraft.Bridge;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
+
+@Mixin(ServerPlayerGameMode.class)
+public abstract class BlockInteractMixin {
+    @Inject(method = "useItemOn", at = @At("HEAD"), cancellable = true)
+    private void scopenet$protectInteraction(ServerPlayer player, Level level, ItemStack stack,
+            InteractionHand hand, BlockHitResult hit, CallbackInfoReturnable<InteractionResult> cir) {
+        if (!Bridge.canModify(player, hit.getBlockPos())
+                || !Bridge.canModify(player, hit.getBlockPos().relative(hit.getDirection()))) {
+            cir.setReturnValue(InteractionResult.FAIL);
+        }
+    }
+}

integrations/minecraft/src/main/java/net/scopenet/minecraft/mixin/BlockItemMixin.java

@@ -4,6 +4,7 @@ import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.InteractionResult;
 import net.minecraft.world.item.BlockItem;
 import net.minecraft.world.item.context.BlockPlaceContext;
+import net.minecraft.core.registries.BuiltInRegistries;
 import net.scopenet.minecraft.Bridge;
 import org.spongepowered.asm.mixin.Mixin;
 import org.spongepowered.asm.mixin.injection.*;
@@ -11,11 +12,20 @@ import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
 
 @Mixin(BlockItem.class)
 public abstract class BlockItemMixin {
+    @Inject(method = "place(Lnet/minecraft/world/item/context/BlockPlaceContext;)Lnet/minecraft/world/InteractionResult;", at = @At("HEAD"), cancellable = true)
+    private void scopenet$protectPlace(BlockPlaceContext context, CallbackInfoReturnable<InteractionResult> cir) {
+        if (context.getPlayer() instanceof ServerPlayer player && !Bridge.canModify(player, context.getClickedPos())) {
+            cir.setReturnValue(InteractionResult.FAIL);
+        }
+    }
+
     @Inject(method = "place(Lnet/minecraft/world/item/context/BlockPlaceContext;)Lnet/minecraft/world/InteractionResult;", at = @At("RETURN"))
     private void scopenet$placed(BlockPlaceContext context, CallbackInfoReturnable<InteractionResult> cir) {
         if (cir.getReturnValue().consumesAction() && context.getPlayer() instanceof ServerPlayer player) {
             Bridge.stat(player, "blocks_placed", 1);
-            Bridge.action(player, "block_placed:" + context.getClickedPos().toShortString(), 1);
+            String material = BuiltInRegistries.BLOCK.getKey(context.getLevel().getBlockState(context.getClickedPos()).getBlock())
+                    .getPath().toUpperCase(java.util.Locale.ROOT);
+            Bridge.action(player, "block_placed:" + material + "@" + player.serverLevel().dimension().location(), 1);
         }
     }
 }

integrations/minecraft/src/main/java/net/scopenet/minecraft/mixin/PlayerMixin.java

@@ -2,6 +2,9 @@ package net.scopenet.minecraft.mixin;
 
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.stats.*;
+import net.minecraft.world.level.block.Block;
+import net.minecraft.world.entity.EntityType;
+import net.minecraft.core.registries.BuiltInRegistries;
 import net.scopenet.minecraft.Bridge;
 import org.spongepowered.asm.mixin.Mixin;
 import org.spongepowered.asm.mixin.injection.*;
@@ -13,8 +16,16 @@ public abstract class PlayerMixin {
     private void scopenet$stat(Stat<?> stat, int amount, CallbackInfo ci) {
         Bridge.action((ServerPlayer) (Object) this, stat.getName(), amount);
         String key = null;
-        if (stat.getType() == Stats.BLOCK_MINED) key = "blocks_broken";
-        else if (stat.getType() == Stats.CUSTOM) {
+        if (stat.getType() == Stats.BLOCK_MINED) {
+            key = "blocks_broken";
+            String material = BuiltInRegistries.BLOCK.getKey((Block) stat.getValue()).getPath().toUpperCase(java.util.Locale.ROOT);
+            Bridge.action((ServerPlayer) (Object) this, "block_broken:" + material + "@"
+                    + ((ServerPlayer) (Object) this).serverLevel().dimension().location(), amount);
+        } else if (stat.getType() == Stats.ENTITY_KILLED) {
+            String entity = BuiltInRegistries.ENTITY_TYPE.getKey((EntityType<?>) stat.getValue()).getPath().toUpperCase(java.util.Locale.ROOT);
+            Bridge.action((ServerPlayer) (Object) this, "mob_kills:" + entity, amount);
+        }
+        if (stat.getType() == Stats.CUSTOM) {
             key = switch (stat.getValue().toString()) {
                 case "minecraft:deaths" -> "deaths";
                 case "minecraft:player_kills" -> "player_kills";

integrations/minecraft/src/main/resources/scopenet.mixins.json

@@ -4,6 +4,6 @@
   "package": "net.scopenet.minecraft.mixin",
   "compatibilityLevel": "JAVA_17",
   "refmap": "scopenet.refmap.json",
-  "mixins": ["DedicatedMixin", "ServerMixin", "LoginMixin", "PlayerMixin", "BlockItemMixin", "ChatMixin", "CommandMixin", "AdvancementMixin"],
+  "mixins": ["DedicatedMixin", "ServerMixin", "LoginMixin", "PlayerMixin", "BlockItemMixin", "BlockBreakMixin", "BlockInteractMixin", "ChatMixin", "CommandMixin", "AdvancementMixin"],
   "injectors": { "defaultRequire": 1 }
 }

integrations/paper/src/main/java/net/scopenet/paper/ScopenetPlugin.java

@@ -4,6 +4,7 @@ import net.scopenet.integration.*;
 import net.scopenet.paper.commands.*;
 import org.bukkit.*;
 import org.bukkit.entity.Player;
+import org.bukkit.block.Block;
 import org.bukkit.event.*;
 import org.bukkit.event.block.*;
 import org.bukkit.event.entity.*;
@@ -11,6 +12,7 @@ import org.bukkit.event.player.*;
 import org.bukkit.event.inventory.InventoryClickEvent;
 import org.bukkit.plugin.java.JavaPlugin;
 import java.util.concurrent.TimeUnit;
+import java.util.UUID;
 
 public final class ScopenetPlugin extends JavaPlugin implements Listener {
     private Integration integration;
@@ -152,6 +154,27 @@ public final class ScopenetPlugin extends JavaPlugin implements Listener {
         }
     }
 
+    private boolean claimsEnabled() {
+        return integration != null && integration.settings().guildsEnabled() && integration.settings().landClaimingEnabled();
+    }
+
+    private boolean protectedFrom(Player player, Block block) {
+        if (!claimsEnabled()) return false;
+        Chunk chunk = block.getChunk();
+        ChunkCheckResult check = integration.checkChunk(dimension(block.getWorld()), chunk.getX(), chunk.getZ(), player.getUniqueId());
+        if (check.allowed()) return false;
+        player.sendMessage(ChatColor.RED + "This chunk is protected by a guild or the claim check is unavailable.");
+        return true;
+    }
+
+    private boolean claimed(Block block) {
+        if (!claimsEnabled()) return false;
+        Chunk chunk = block.getChunk();
+        // A non-member identity protects environmental changes, including
+        // while the panel is unavailable and the lookup is pending.
+        return integration.checkChunk(dimension(block.getWorld()), chunk.getX(), chunk.getZ(), new UUID(0, 0)).claimed();
+    }
+
     @EventHandler(priority = EventPriority.NORMAL, ignoreCancelled = true)
     public void broken(BlockBreakEvent event) {
         if (integration != null && integration.settings().guildsEnabled() && integration.settings().landClaimingEnabled()) {
@@ -164,6 +187,8 @@ public final class ScopenetPlugin extends JavaPlugin implements Listener {
             }
         }
         add(event.getPlayer(), "blocks_broken");
+        if (integration != null) integration.activity.action(event.getPlayer().getUniqueId(), event.getPlayer().getName(),
+                "block_broken:" + event.getBlock().getType().name() + "@" + dimension(event.getBlock().getWorld()), 1);
     }
 
     @EventHandler(priority = EventPriority.NORMAL, ignoreCancelled = true)
@@ -178,6 +203,64 @@ public final class ScopenetPlugin extends JavaPlugin implements Listener {
             }
         }
         add(event.getPlayer(), "blocks_placed");
+        if (integration != null) integration.activity.action(event.getPlayer().getUniqueId(), event.getPlayer().getName(),
+                "block_placed:" + event.getBlock().getType().name() + "@" + dimension(event.getBlock().getWorld()), 1);
+    }
+
+    @EventHandler(priority = EventPriority.HIGHEST, ignoreCancelled = true)
+    public void interact(PlayerInteractEvent event) {
+        if (event.getClickedBlock() != null && event.getAction() == Action.RIGHT_CLICK_BLOCK
+                && protectedFrom(event.getPlayer(), event.getClickedBlock())) event.setCancelled(true);
+    }
+
+    @EventHandler(priority = EventPriority.HIGHEST, ignoreCancelled = true)
+    public void bucketEmpty(PlayerBucketEmptyEvent event) {
+        if (protectedFrom(event.getPlayer(), event.getBlockClicked().getRelative(event.getBlockFace()))) event.setCancelled(true);
+    }
+
+    @EventHandler(priority = EventPriority.HIGHEST, ignoreCancelled = true)
+    public void bucketFill(PlayerBucketFillEvent event) {
+        if (protectedFrom(event.getPlayer(), event.getBlockClicked())) event.setCancelled(true);
+    }
+
+    @EventHandler(priority = EventPriority.HIGHEST, ignoreCancelled = true)
+    public void entityExplode(EntityExplodeEvent event) {
+        event.blockList().removeIf(this::claimed);
+    }
+
+    @EventHandler(priority = EventPriority.HIGHEST, ignoreCancelled = true)
+    public void blockExplode(BlockExplodeEvent event) {
+        event.blockList().removeIf(this::claimed);
+    }
+
+    @EventHandler(priority = EventPriority.HIGHEST, ignoreCancelled = true)
+    public void pistonExtend(BlockPistonExtendEvent event) {
+        if (event.getBlocks().stream().anyMatch(block -> claimed(block) || claimed(block.getRelative(event.getDirection())))) event.setCancelled(true);
+    }
+
+    @EventHandler(priority = EventPriority.HIGHEST, ignoreCancelled = true)
+    public void pistonRetract(BlockPistonRetractEvent event) {
+        if (event.getBlocks().stream().anyMatch(block -> claimed(block) || claimed(block.getRelative(event.getDirection())))) event.setCancelled(true);
+    }
+
+    @EventHandler(priority = EventPriority.HIGHEST, ignoreCancelled = true)
+    public void fluid(BlockFromToEvent event) {
+        if (claimed(event.getToBlock())) event.setCancelled(true);
+    }
+
+    @EventHandler(priority = EventPriority.HIGHEST, ignoreCancelled = true)
+    public void fire(BlockIgniteEvent event) {
+        if (claimed(event.getBlock())) event.setCancelled(true);
+    }
+
+    @EventHandler(priority = EventPriority.HIGHEST, ignoreCancelled = true)
+    public void burn(BlockBurnEvent event) {
+        if (claimed(event.getBlock())) event.setCancelled(true);
+    }
+
+    @EventHandler(priority = EventPriority.HIGHEST, ignoreCancelled = true)
+    public void entityChangeBlock(EntityChangeBlockEvent event) {
+        if (claimed(event.getBlock())) event.setCancelled(true);
     }
 
     @EventHandler(priority = EventPriority.MONITOR, ignoreCancelled = true)
@@ -231,6 +314,10 @@ public final class ScopenetPlugin extends JavaPlugin implements Listener {
                     event instanceof PlayerDeathEvent death ? death.getDeathMessage() : null);
         }
         Player killer = event.getEntity().getKiller();
-        if (killer != null) add(killer, event.getEntity() instanceof Player ? "player_kills" : "mob_kills");
+        if (killer != null) {
+            add(killer, event.getEntity() instanceof Player ? "player_kills" : "mob_kills");
+            if (integration != null && !(event.getEntity() instanceof Player)) integration.activity.action(
+                    killer.getUniqueId(), killer.getName(), "mob_kills:" + event.getEntityType().name(), 1);
+        }
     }
 }

integrations/paper/src/main/java/net/scopenet/paper/commands/EconomyHandler.java

@@ -19,13 +19,13 @@ import org.bukkit.event.inventory.InventoryClickEvent;
 import org.bukkit.event.inventory.InventoryCloseEvent;
 import org.bukkit.inventory.Inventory;
 import org.bukkit.inventory.ItemStack;
-
 import java.util.*;
 import java.util.concurrent.ConcurrentHashMap;
 
 public final class EconomyHandler implements CommandExecutor, Listener {
     private final ScopenetPlugin plugin;
     private final Integration integration;
+    private final EconomyOperations operations;
 
     private static final String GUI_SHOP_TITLE = ChatColor.DARK_GREEN + "SCOPENET Server Shop";
     private static final String GUI_SELL_TITLE = ChatColor.GOLD + "Sell Chest (Place Items Here)";
@@ -35,10 +35,8 @@ public final class EconomyHandler implements CommandExecutor, Listener {
     // Trade sessions: maps player UUID to active trade session
     private final Map<UUID, TradeSession> activeTrades = new ConcurrentHashMap<>();
 
-    // Marketplace: slot index → listing id (populated when the GUI is opened)
-    // Note: this is per-opening; multiple concurrent GUIs share the same map which is
-    // acceptable because listings are keyed by slot and players cannot open two markets.
-    private final Map<Integer, Long> activeMarketListings = new ConcurrentHashMap<>();
+    // Each open inventory must retain its own snapshot of listing IDs.
+    private final Map<Inventory, Map<Integer, Long>> activeMarketListings = new IdentityHashMap<>();
 
     // Standard sell values for common items
     private static final Map<Material, Double> ITEM_SELL_VALUES = new HashMap<>();
@@ -73,6 +71,13 @@ public final class EconomyHandler implements CommandExecutor, Listener {
     public EconomyHandler(ScopenetPlugin plugin, Integration integration) {
         this.plugin = plugin;
         this.integration = integration;
+        this.operations = new EconomyOperations(plugin, integration);
+    }
+
+    private void giveOrDrop(Player player, ItemStack item) {
+        for (ItemStack remaining : player.getInventory().addItem(item).values()) {
+            player.getWorld().dropItemNaturally(player.getLocation(), remaining);
+        }
     }
 
     @Override
@@ -222,27 +227,16 @@ public final class EconomyHandler implements CommandExecutor, Listener {
                 player.sendMessage(ChatColor.RED + "This item (" + hand.getType().name() + ") cannot be sold to the server shop.");
                 return;
             }
-            int amount = hand.getAmount();
+            ItemStack sold = hand.clone();
+            int amount = sold.getAmount();
             double total = unitPrice * amount;
-            player.sendMessage(ChatColor.GRAY + "Processing sale...");
-
-            // FIX #5: Credit FIRST, only remove item after the server confirms payment.
-            Bukkit.getScheduler().runTaskAsynchronously(plugin, () -> {
-                try {
-                    // FIX #4: atomic addBalance – no read-modify-write race condition.
-                    double newBal = integration.client().addBalance(
-                            player.getUniqueId(), player.getName(), total, "Sell hand: " + hand.getType().name());
-                    Bukkit.getScheduler().runTask(plugin, () -> {
-                        player.getInventory().setItemInMainHand(null);
-                        player.sendMessage(ChatColor.GREEN + "Sold " + amount + "x " + hand.getType().name() + " for "
-                                + ChatColor.YELLOW + "$" + String.format(Locale.US, "%,.2f", total) + ChatColor.GREEN
-                                + "! Balance: " + ChatColor.YELLOW + "$" + String.format(Locale.US, "%,.2f", newBal));
-                    });
-                } catch (Exception e) {
-                    // Item was NOT removed – nothing to restore.
-                    player.sendMessage(ChatColor.RED + "Failed to credit sell balance: " + e.getMessage());
-                }
-            });
+            JsonObject payload = new JsonObject();
+            payload.addProperty("uuid", player.getUniqueId().toString());
+            payload.addProperty("username", player.getName());
+            payload.addProperty("delta", total);
+            payload.addProperty("description", "Sell hand: " + sold.getType().name());
+            player.getInventory().setItemInMainHand(null);
+            if (!operations.enqueue(player, "economy/adjust", payload, List.of(sold), null)) giveOrDrop(player, sold);
             return;
         }
 
@@ -268,27 +262,25 @@ public final class EconomyHandler implements CommandExecutor, Listener {
                 return;
             }
 
-            int amount = hand.getAmount();
-            String itemId = hand.getType().name();
-            String itemName = hand.hasItemMeta() && hand.getItemMeta().hasDisplayName()
-                    ? hand.getItemMeta().getDisplayName() : hand.getType().name().replace('_', ' ');
+            ItemStack listed = hand.clone();
+            int amount = listed.getAmount();
+            String itemId = listed.getType().name();
+            String itemName = listed.hasItemMeta() && listed.getItemMeta().hasDisplayName()
+                    ? listed.getItemMeta().getDisplayName() : listed.getType().name().replace('_', ' ');
+            JsonObject payload = new JsonObject();
+            payload.addProperty("seller_uuid", player.getUniqueId().toString());
+            payload.addProperty("seller_name", player.getName());
+            payload.addProperty("item_id", itemId);
+            payload.addProperty("item_name", itemName);
+            payload.addProperty("amount", amount);
+            payload.addProperty("price", price);
+            payload.addProperty("item_data", EconomyOperations.encode(listed));
 
-            player.sendMessage(ChatColor.GRAY + "Listing item on marketplace...");
-
-            // FIX #5: Only remove item after the API accepted the listing.
-            Bukkit.getScheduler().runTaskAsynchronously(plugin, () -> {
-                try {
-                    integration.client().marketList(player.getUniqueId(), player.getName(), itemId, itemName, amount, price);
-                    Bukkit.getScheduler().runTask(plugin, () -> {
-                        player.getInventory().setItemInMainHand(null);
-                        player.sendMessage(ChatColor.GREEN + "Successfully listed " + ChatColor.YELLOW + amount + "x " + itemName
-                                + ChatColor.GREEN + " on the market for " + ChatColor.YELLOW + "$" + String.format(Locale.US, "%,.2f", price) + "!");
-                    });
-                } catch (Exception e) {
-                    player.sendMessage(ChatColor.RED + "Market listing failed: " + e.getMessage());
-                    // Item was never removed; no restoration needed.
-                }
-            });
+            // Escrow the exact stack before persisting a retryable operation.
+            player.getInventory().setItemInMainHand(null);
+            if (!operations.enqueue(player, "economy/market/list", payload, List.of(listed), null)) {
+                giveOrDrop(player, listed);
+            }
             return;
         }
 
@@ -307,9 +299,11 @@ public final class EconomyHandler implements CommandExecutor, Listener {
             try {
                 JsonArray listings = integration.client().getMarketListings();
                 Bukkit.getScheduler().runTask(plugin, () -> {
+                    if (player.getOpenInventory().getTopInventory() != inv) return;
                     // Clear loading placeholders
                     for (int i = 0; i < 45; i++) inv.setItem(i, null);
-                    activeMarketListings.clear();
+                    Map<Integer, Long> inventoryListings = new HashMap<>();
+                    activeMarketListings.put(inv, inventoryListings);
                     if (listings.size() == 0) {
                         inv.setItem(22, GuiHelper.createItem(Material.BARRIER, "&cNo listings", "&7Be the first to sell something!"));
                         return;
@@ -326,7 +320,7 @@ public final class EconomyHandler implements CommandExecutor, Listener {
                         double listPrice = listing.has("price") ? listing.get("price").getAsDouble() : 0;
                         Material mat;
                         try { mat = Material.valueOf(listItemId); } catch (Exception ex) { mat = Material.PAPER; }
-                        activeMarketListings.put(slot, id);
+                        inventoryListings.put(slot, id);
                         inv.setItem(slot, GuiHelper.createItem(mat, listAmt,
                                 "&f" + listItemName + " &7(x" + listAmt + ")",
                                 "&7Seller: &f" + sellerName,
@@ -414,59 +408,25 @@ public final class EconomyHandler implements CommandExecutor, Listener {
             }
 
             if (price <= 0) return;
-            final double finalPrice = price;
-            final ItemStack toBuy = clicked.clone();
-
-            player.sendMessage(ChatColor.GRAY + "Processing purchase...");
-            Bukkit.getScheduler().runTaskAsynchronously(plugin, () -> {
-                try {
-                    // FIX #4: Atomic debit – the panel validates the balance and deducts atomically.
-                    double newBal = integration.client().addBalance(
-                            player.getUniqueId(), player.getName(), -finalPrice, "Shop purchase: " + toBuy.getType().name());
-                    Bukkit.getScheduler().runTask(plugin, () -> {
-                        ItemStack give = new ItemStack(toBuy.getType(), toBuy.getAmount());
-                        player.getInventory().addItem(give);
-                        player.sendMessage(ChatColor.GREEN + "Purchased " + give.getAmount() + "x " + give.getType().name()
-                                + " for " + ChatColor.YELLOW + "$" + String.format(Locale.US, "%,.2f", finalPrice) + ChatColor.GREEN
-                                + "! Balance: " + ChatColor.YELLOW + "$" + String.format(Locale.US, "%,.2f", newBal));
-                    });
-                } catch (Exception e) {
-                    player.sendMessage(ChatColor.RED + "Shop transaction failed: " + e.getMessage());
-                }
-            });
+            ItemStack purchase = new ItemStack(clicked.getType(), clicked.getAmount());
+            JsonObject payload = new JsonObject();
+            payload.addProperty("uuid", player.getUniqueId().toString());
+            payload.addProperty("username", player.getName());
+            payload.addProperty("delta", -price);
+            payload.addProperty("description", "Shop purchase: " + purchase.getType().name());
+            operations.enqueue(player, "economy/adjust", payload, Collections.emptyList(), purchase);
         } else if (title.equals(GUI_MARKET_TITLE)) {
             // FIX #2: Always cancel market clicks – purchase only via the API.
             event.setCancelled(true);
             int slot = event.getRawSlot();
-            Long listingId = activeMarketListings.get(slot);
+            Long listingId = activeMarketListings.getOrDefault(event.getInventory(), Collections.emptyMap()).get(slot);
             if (listingId == null || listingId < 0) return;
 
-            player.sendMessage(ChatColor.GRAY + "Processing market purchase...");
-            final long fListingId = listingId;
-            Bukkit.getScheduler().runTaskAsynchronously(plugin, () -> {
-                try {
-                    JsonObject result = integration.client().marketBuy(fListingId, player.getUniqueId(), player.getName());
-                    String itemId = result.has("item_id") ? result.get("item_id").getAsString() : null;
-                    int amt = result.has("amount") ? result.get("amount").getAsInt() : 1;
-                    double newBal = result.has("new_balance") ? result.get("new_balance").getAsDouble() : 0;
-                    if (itemId != null) {
-                        Bukkit.getScheduler().runTask(plugin, () -> {
-                            try {
-                                Material mat = Material.valueOf(itemId);
-                                player.getInventory().addItem(new ItemStack(mat, amt));
-                                player.sendMessage(ChatColor.GREEN + "Purchased " + amt + "x " + mat.name()
-                                        + " from the market! Balance: " + ChatColor.YELLOW + "$" + String.format(Locale.US, "%,.2f", newBal));
-                            } catch (Exception ex) {
-                                player.sendMessage(ChatColor.GREEN + "Purchase successful! Balance: " + ChatColor.YELLOW + "$" + String.format(Locale.US, "%,.2f", newBal));
-                            }
-                        });
-                    } else {
-                        player.sendMessage(ChatColor.GREEN + "Market purchase successful!");
-                    }
-                } catch (Exception e) {
-                    player.sendMessage(ChatColor.RED + "Market purchase failed: " + e.getMessage());
-                }
-            });
+            JsonObject payload = new JsonObject();
+            payload.addProperty("listing_id", listingId);
+            payload.addProperty("buyer_uuid", player.getUniqueId().toString());
+            payload.addProperty("buyer_name", player.getName());
+            operations.enqueue(player, "economy/market/buy", payload, Collections.emptyList(), null);
         } else if (title.startsWith(GUI_TRADE_PREFIX)) {
             TradeSession session = activeTrades.get(player.getUniqueId());
             if (session != null) {
@@ -480,8 +440,12 @@ public final class EconomyHandler implements CommandExecutor, Listener {
         if (!(event.getPlayer() instanceof Player player)) return;
         String title = event.getView().getTitle();
 
+        if (title.equals(GUI_MARKET_TITLE)) {
+            activeMarketListings.remove(event.getInventory());
+        }
+
         if (title.equals(GUI_SELL_TITLE)) {
-            // FIX #4/#5: Collect items, credit atomically, only confirm sale after success.
+            // Move sellable items to durable escrow before crediting the balance.
             Inventory inv = event.getInventory();
             List<ItemStack> soldItems = new ArrayList<>();
             List<ItemStack> unsellable = new ArrayList<>();
@@ -499,33 +463,20 @@ public final class EconomyHandler implements CommandExecutor, Listener {
                     unsellable.add(item.clone());
                 }
             }
+            inv.clear();
 
             // Return unsellable items immediately
-            for (ItemStack it : unsellable) {
-                player.getInventory().addItem(it);
-            }
+            for (ItemStack it : unsellable) giveOrDrop(player, it);
 
             if (totalEarned > 0) {
-                final double earned = totalEarned;
-                final int itemsCount = countSold;
-                // FIX #4: addBalance is atomic – no read-modify-write race.
-                Bukkit.getScheduler().runTaskAsynchronously(plugin, () -> {
-                    try {
-                        double newBal = integration.client().addBalance(
-                                player.getUniqueId(), player.getName(), earned, "Sell chest: " + itemsCount + " items");
-                        player.sendMessage(ChatColor.GREEN + "Sold " + itemsCount + " items for "
-                                + ChatColor.YELLOW + "$" + String.format(Locale.US, "%,.2f", earned) + ChatColor.GREEN + "!"
-                                + " Balance: " + ChatColor.YELLOW + "$" + String.format(Locale.US, "%,.2f", newBal));
-                    } catch (Exception e) {
-                        // FIX #5: Credit failed – return items to player.
-                        player.sendMessage(ChatColor.RED + "Failed to credit earnings, items returned: " + e.getMessage());
-                        Bukkit.getScheduler().runTask(plugin, () -> {
-                            for (ItemStack it : soldItems) {
-                                player.getInventory().addItem(it);
-                            }
-                        });
-                    }
-                });
+                JsonObject payload = new JsonObject();
+                payload.addProperty("uuid", player.getUniqueId().toString());
+                payload.addProperty("username", player.getName());
+                payload.addProperty("delta", totalEarned);
+                payload.addProperty("description", "Sell chest: " + countSold + " items");
+                if (!operations.enqueue(player, "economy/adjust", payload, soldItems, null)) {
+                    for (ItemStack item : soldItems) giveOrDrop(player, item);
+                }
             }
         } else if (title.startsWith(GUI_TRADE_PREFIX)) {
             TradeSession session = activeTrades.get(player.getUniqueId());

integrations/paper/src/main/java/net/scopenet/paper/commands/EconomyOperations.java

@@ -121,8 +121,14 @@ final class EconomyOperations {
             for (ItemStack item : items) give(player, item);
             jobs.remove(id);
             save();
-            player.sendMessage(job.has("error") ? ChatColor.RED + "Transaction rejected; held items returned: " + job.get("error").getAsString()
-                : ChatColor.GREEN + "Transaction completed.");
+            if (job.has("error")) {
+                player.sendMessage(ChatColor.RED + "Transaction rejected; held items returned: " + job.get("error").getAsString());
+            } else {
+                JsonObject result = job.getAsJsonObject("result");
+                JsonElement balanceValue = result.has("new_balance") ? result.get("new_balance") : result.get("balance");
+                String balance = balanceValue != null ? " Balance: $" + String.format(Locale.US, "%,.2f", balanceValue.getAsDouble()) : "";
+                player.sendMessage(ChatColor.GREEN + "Transaction completed." + balance);
+            }
         } catch (Exception e) { plugin.getLogger().severe("Economy delivery requires attention for " + id + ": " + e.getMessage()); }
     }
 }