diff --git a/src/game/economy/service.ts b/src/game/economy/service.ts
new file mode 100644
index 0000000..b19c043
--- /dev/null
+++ b/src/game/economy/service.ts
@@ -0,0 +1,326 @@
+import { prisma } from '../../core/database/prisma';
+import type { ItemProps, InventoryState, Price, OpenChestResult } from './types';
+import type { Prisma } from '@prisma/client';
+
+// Utilidades de tiempo
+function now(): Date {
+  return new Date();
+}
+
+function isWithin(date: Date, from?: Date | null, to?: Date | null): boolean {
+  if (from && date < from) return false;
+  if (to && date > to) return false;
+  return true;
+}
+
+// Resuelve un EconomyItem por key con alcance de guild o global
+export async function findItemByKey(guildId: string, key: string) {
+  // buscamos ítem por guildId específico primero, si no, por global (guildId null)
+  const item = await prisma.economyItem.findFirst({
+    where: {
+      key,
+      OR: [{ guildId }, { guildId: null }],
+    },
+    orderBy: [
+      // preferir coincidencia del servidor
+      { guildId: 'desc' },
+    ],
+  });
+  return item;
+}
+
+export async function getOrCreateWallet(userId: string, guildId: string) {
+  return prisma.economyWallet.upsert({
+    where: { userId_guildId: { userId, guildId } },
+    update: {},
+    create: { userId, guildId },
+  });
+}
+
+export async function adjustCoins(userId: string, guildId: string, delta: number) {
+  const wallet = await getOrCreateWallet(userId, guildId);
+  const next = Math.max(0, wallet.coins + delta);
+  return prisma.economyWallet.update({
+    where: { userId_guildId: { userId, guildId } },
+    data: { coins: next },
+  });
+}
+
+export type EnsureInventoryOptions = { createIfMissing?: boolean };
+
+export async function getInventoryEntryByItemId(userId: string, guildId: string, itemId: string, opts?: EnsureInventoryOptions) {
+  const existing = await prisma.inventoryEntry.findUnique({
+    where: { userId_guildId_itemId: { userId, guildId, itemId } },
+  });
+  if (existing) return existing;
+  if (!opts?.createIfMissing) return null;
+  return prisma.inventoryEntry.create({ data: { userId, guildId, itemId, quantity: 0 } });
+}
+
+export async function getInventoryEntry(userId: string, guildId: string, itemKey: string, opts?: EnsureInventoryOptions) {
+  const item = await findItemByKey(guildId, itemKey);
+  if (!item) throw new Error(`Item key not found: ${itemKey}`);
+  const entry = await getInventoryEntryByItemId(userId, guildId, item.id, opts);
+  return { item, entry } as const;
+}
+
+function parseItemProps(json: unknown): ItemProps {
+  if (!json || typeof json !== 'object') return {};
+  return json as ItemProps;
+}
+
+function parseState(json: unknown): InventoryState {
+  if (!json || typeof json !== 'object') return {};
+  return json as InventoryState;
+}
+
+function checkUsableWindow(item: { usableFrom: Date | null; usableTo: Date | null; props: any }) {
+  const props = parseItemProps(item.props);
+  const from = props.usableFrom ? new Date(props.usableFrom) : item.usableFrom;
+  const to = props.usableTo ? new Date(props.usableTo) : item.usableTo;
+  if (!isWithin(now(), from ?? null, to ?? null)) {
+    throw new Error('Item no usable por ventana de tiempo');
+  }
+}
+
+function checkAvailableWindow(item: { availableFrom: Date | null; availableTo: Date | null; props: any }) {
+  const props = parseItemProps(item.props);
+  const from = props.availableFrom ? new Date(props.availableFrom) : item.availableFrom;
+  const to = props.availableTo ? new Date(props.availableTo) : item.availableTo;
+  if (!isWithin(now(), from ?? null, to ?? null)) {
+    throw new Error('Item no disponible para adquirir');
+  }
+}
+
+// Agrega cantidad respetando maxPerInventory y stackable
+export async function addItemByKey(userId: string, guildId: string, itemKey: string, qty: number) {
+  if (qty <= 0) return { added: 0 } as const;
+  const found = await getInventoryEntry(userId, guildId, itemKey, { createIfMissing: true });
+  const item = found.item;
+  const entry = found.entry;
+  if (!entry) throw new Error('No se pudo crear/obtener inventario');
+  checkAvailableWindow(item);
+
+  const max = item.maxPerInventory ?? Number.MAX_SAFE_INTEGER;
+  if (item.stackable) {
+    const currentQty = entry.quantity ?? 0;
+    const added = Math.max(0, Math.min(qty, Math.max(0, max - currentQty)));
+    if (added === 0) return { added: 0 } as const;
+    const updated = await prisma.inventoryEntry.update({
+      where: { userId_guildId_itemId: { userId, guildId, itemId: item.id } },
+      data: { quantity: { increment: added } },
+    });
+    return { added, entry: updated } as const;
+  } else {
+    // No apilable: usar state.instances
+    const state = parseState(entry.state);
+    state.instances ??= [];
+    const canAdd = Math.max(0, Math.min(qty, Math.max(0, max - state.instances.length)));
+    for (let i = 0; i < canAdd; i++) state.instances.push({});
+    const updated = await prisma.inventoryEntry.update({
+      where: { userId_guildId_itemId: { userId, guildId, itemId: item.id } },
+      data: { state: state as unknown as Prisma.InputJsonValue, quantity: state.instances.length },
+    });
+    return { added: canAdd, entry: updated } as const;
+  }
+}
+
+export async function consumeItemByKey(userId: string, guildId: string, itemKey: string, qty: number) {
+  if (qty <= 0) return { consumed: 0 } as const;
+  const { item, entry } = await getInventoryEntry(userId, guildId, itemKey);
+  if (!entry || (entry.quantity ?? 0) <= 0) return { consumed: 0 } as const;
+
+  if (item.stackable) {
+    const consumed = Math.min(qty, entry.quantity);
+    const updated = await prisma.inventoryEntry.update({
+      where: { userId_guildId_itemId: { userId, guildId, itemId: item.id } },
+      data: { quantity: { decrement: consumed } },
+    });
+    return { consumed, entry: updated } as const;
+  } else {
+    const state = parseState(entry.state);
+    const instances = state.instances ?? [];
+    const consumed = Math.min(qty, instances.length);
+    if (consumed === 0) return { consumed: 0 } as const;
+    instances.splice(0, consumed);
+    const newState: InventoryState = { ...state, instances };
+    const updated = await prisma.inventoryEntry.update({
+      where: { userId_guildId_itemId: { userId, guildId, itemId: item.id } },
+      data: { state: newState as unknown as Prisma.InputJsonValue, quantity: instances.length },
+    });
+    return { consumed, entry: updated } as const;
+  }
+}
+
+export async function openChestByKey(userId: string, guildId: string, itemKey: string): Promise<OpenChestResult> {
+  const { item, entry } = await getInventoryEntry(userId, guildId, itemKey);
+  if (!entry || (entry.quantity ?? 0) <= 0) throw new Error('No tienes este cofre');
+  checkUsableWindow(item);
+
+  const props = parseItemProps(item.props);
+  const chest = props.chest ?? {};
+  if (!chest.enabled) throw new Error('Este ítem no se puede abrir');
+
+  const rewards = Array.isArray(chest.rewards) ? chest.rewards : [];
+  const result: OpenChestResult = { coinsDelta: 0, itemsToAdd: [], rolesToGrant: [], consumed: false };
+
+  for (const r of rewards) {
+    if (r.type === 'coins') result.coinsDelta += Math.max(0, r.amount);
+    else if (r.type === 'item') result.itemsToAdd.push({ itemKey: r.itemKey, itemId: r.itemId, qty: r.qty });
+    else if (r.type === 'role') result.rolesToGrant.push(r.roleId);
+  }
+
+  if (result.coinsDelta) await adjustCoins(userId, guildId, result.coinsDelta);
+  for (const it of result.itemsToAdd) {
+    if (it.itemKey) await addItemByKey(userId, guildId, it.itemKey, it.qty);
+    else if (it.itemId) {
+      const item = await prisma.economyItem.findUnique({ where: { id: it.itemId } });
+      if (item) await addItemByKey(userId, guildId, item.key, it.qty);
+    }
+  }
+
+  if (chest.consumeOnOpen) {
+    const c = await consumeItemByKey(userId, guildId, itemKey, 1);
+    result.consumed = c.consumed > 0;
+  }
+
+  return result;
+}
+
+export async function craftByProductKey(userId: string, guildId: string, productKey: string) {
+  const product = await findItemByKey(guildId, productKey);
+  if (!product) throw new Error(`Producto no encontrado: ${productKey}`);
+  const recipe = await prisma.itemRecipe.findUnique({
+    where: { productItemId: product.id },
+    include: { ingredients: true },
+  });
+  if (!recipe) throw new Error('No existe receta para este ítem');
+
+  // Verificar ingredientes suficientes
+  const shortages: string[] = [];
+  for (const ing of recipe.ingredients) {
+    const inv = await prisma.inventoryEntry.findUnique({ where: { userId_guildId_itemId: { userId, guildId, itemId: ing.itemId } } });
+    const have = inv?.quantity ?? 0;
+    if (have < ing.quantity) shortages.push(ing.itemId);
+  }
+  if (shortages.length) throw new Error('Ingredientes insuficientes');
+
+  // Consumir ingredientes
+  for (const ing of recipe.ingredients) {
+    await prisma.inventoryEntry.update({
+      where: { userId_guildId_itemId: { userId, guildId, itemId: ing.itemId } },
+      data: { quantity: { decrement: ing.quantity } },
+    });
+  }
+
+  // Agregar producto
+  const add = await addItemByKey(userId, guildId, product.key, recipe.productQuantity);
+  return { added: add.added, product } as const;
+}
+
+export async function buyFromOffer(userId: string, guildId: string, offerId: string, qty = 1) {
+  if (qty <= 0) throw new Error('Cantidad inválida');
+  const offer = await prisma.shopOffer.findUnique({ where: { id: offerId } });
+  if (!offer || offer.guildId !== guildId) throw new Error('Oferta no encontrada');
+  if (!offer.enabled) throw new Error('Oferta deshabilitada');
+  const nowD = now();
+  if (!isWithin(nowD, offer.startAt ?? null, offer.endAt ?? null)) throw new Error('Oferta fuera de fecha');
+
+  const price = (offer.price as unknown as Price) ?? {};
+  // Limites
+  if (offer.perUserLimit != null) {
+    const count = await prisma.shopPurchase.aggregate({
+      where: { offerId: offer.id, userId, guildId },
+      _sum: { qty: true },
+    });
+    const already = count._sum.qty ?? 0;
+    if (already + qty > offer.perUserLimit) throw new Error('Excede el límite por usuario');
+  }
+
+  if (offer.stock != null) {
+    if (offer.stock < qty) throw new Error('Stock insuficiente');
+  }
+
+  // Cobro: coins
+  if (price.coins && price.coins > 0) {
+    const wallet = await getOrCreateWallet(userId, guildId);
+    const total = price.coins * qty;
+    if (wallet.coins < total) throw new Error('Monedas insuficientes');
+    await prisma.economyWallet.update({ where: { userId_guildId: { userId, guildId } }, data: { coins: wallet.coins - total } });
+  }
+  // Cobro: items
+  if (price.items && price.items.length) {
+    for (const comp of price.items) {
+      const key = comp.itemKey;
+      const compQty = comp.qty * qty;
+      let itemId: string | null = null;
+      if (key) {
+        const it = await findItemByKey(guildId, key);
+        if (!it) throw new Error(`Item de precio no encontrado: ${key}`);
+        itemId = it.id;
+      } else if (comp.itemId) {
+        itemId = comp.itemId;
+      }
+      if (!itemId) throw new Error('Item de precio inválido');
+      const inv = await prisma.inventoryEntry.findUnique({ where: { userId_guildId_itemId: { userId, guildId, itemId } } });
+      if ((inv?.quantity ?? 0) < compQty) throw new Error('No tienes suficientes items para pagar');
+    }
+    // si todo está ok, descontar
+    for (const comp of price.items) {
+      const key = comp.itemKey;
+      const compQty = comp.qty * qty;
+      let itemId: string | null = null;
+      if (key) {
+        const it = await findItemByKey(guildId, key);
+        itemId = it?.id ?? null;
+      } else if (comp.itemId) {
+        itemId = comp.itemId;
+      }
+      if (!itemId) continue;
+      await prisma.inventoryEntry.update({ where: { userId_guildId_itemId: { userId, guildId, itemId } }, data: { quantity: { decrement: compQty } } });
+    }
+  }
+
+  // Entregar producto
+  const item = await prisma.economyItem.findUnique({ where: { id: offer.itemId } });
+  if (!item) throw new Error('Ítem de oferta no existente');
+  await addItemByKey(userId, guildId, item.key, qty);
+
+  // Registrar compra
+  await prisma.shopPurchase.create({ data: { offerId: offer.id, userId, guildId, qty } });
+
+  // Reducir stock global
+  if (offer.stock != null) {
+    await prisma.shopOffer.update({ where: { id: offer.id }, data: { stock: offer.stock - qty } });
+  }
+
+  return { ok: true, item, qty } as const;
+}
+
+// ---------------------------
+// Mutaciones
+// ---------------------------
+export async function findMutationByKey(guildId: string, key: string) {
+  return prisma.itemMutation.findFirst({
+    where: { key, OR: [{ guildId }, { guildId: null }] },
+    orderBy: [{ guildId: 'desc' }],
+  });
+}
+
+export async function applyMutationToInventory(userId: string, guildId: string, itemKey: string, mutationKey: string) {
+  const { item, entry } = await getInventoryEntry(userId, guildId, itemKey, { createIfMissing: true });
+  if (!entry) throw new Error('Inventario inexistente');
+
+  // Política de mutaciones
+  const props = parseItemProps(item.props);
+  const policy = props.mutationPolicy;
+  if (policy?.deniedKeys?.includes(mutationKey)) throw new Error('Mutación denegada');
+  if (policy?.allowedKeys && !policy.allowedKeys.includes(mutationKey)) throw new Error('Mutación no permitida');
+
+  const mutation = await findMutationByKey(guildId, mutationKey);
+  if (!mutation) throw new Error('Mutación no encontrada');
+
+  // Registrar vínculo
+  await prisma.inventoryItemMutation.create({ data: { inventoryId: entry.id, mutationId: mutation.id } });
+  return { ok: true } as const;
+}