diff --git a/SVSim.Database/Repositories/Card/CardInventoryRepository.cs b/SVSim.Database/Repositories/Card/CardInventoryRepository.cs
index fb7690f..6c1cc53 100644
--- a/SVSim.Database/Repositories/Card/CardInventoryRepository.cs
+++ b/SVSim.Database/Repositories/Card/CardInventoryRepository.cs
@@ -2,18 +2,19 @@ using Microsoft.EntityFrameworkCore;
 using SVSim.Database.Enums;
 using SVSim.Database.Models;
 using SVSim.Database.Services;
+using SVSim.Database.Services.Inventory;
 
 namespace SVSim.Database.Repositories.Card;
 
 public class CardInventoryRepository : ICardInventoryRepository
 {
     private readonly SVSimDbContext _db;
-    private readonly RewardGrantService _grants;
+    private readonly IInventoryService _inv;
 
-    public CardInventoryRepository(SVSimDbContext db, RewardGrantService grants)
+    public CardInventoryRepository(SVSimDbContext db, IInventoryService inv)
     {
         _db = db;
-        _grants = grants;
+        _inv = inv;
     }
 
     public async Task<DestructOutcome> DestructCards(long viewerId, IReadOnlyDictionary<long, int> destructCounts)
@@ -129,30 +130,27 @@ public class CardInventoryRepository : ICardInventoryRepository
             totalCost += (ulong)catalogCard.CollectionInfo.CraftCost * (ulong)num;
         }
 
-        // insufficient_vials checked after summing the full batch — all-or-nothing
+        // insufficient_vials pre-check (validation-before-mutation atomicity, keeps same error ordering)
         if (viewer.Currency.RedEther < totalCost)
             return CreateOutcome.Fail(CreateError.InsufficientVials);
 
-        using var tx = await _db.Database.BeginTransactionAsync();
+        // Mutation phase via InventoryService transaction — freeplay-aware RedEther debit,
+        // card grants with cosmetic cascade.
+        await using var tx = await _inv.BeginAsync(viewerId);
 
-        // Debit RedEther directly. ApplyAsync only credits — debit-pair operations live in this
-        // repo, symmetric with destruct.
-        viewer.Currency.RedEther -= totalCost;
+        var spendResult = await tx.TrySpendAsync(SpendCurrency.RedEther, (long)totalCost);
+        if (!spendResult.Success)
+            return CreateOutcome.Fail(CreateError.InsufficientVials);
 
-        // Per-card grant via RewardGrantService — single source of truth for Card-typed grants,
-        // and fires the CardCosmeticReward cascade for first-time owners. See
-        // feedback_reward_grant_service memory.
         var allGrants = new List<GrantedReward>();
         foreach (var (cardId, num) in createCounts)
         {
-            var granted = await _grants.ApplyAsync(viewer, UserGoodsType.Card, cardId, num);
+            var granted = await tx.GrantAsync(UserGoodsType.Card, cardId, num);
             allGrants.AddRange(granted);
         }
 
-        await _db.SaveChangesAsync();
         await tx.CommitAsync();
-
-        return CreateOutcome.Ok(new CreateResult(viewer.Currency.RedEther, allGrants));
+        return CreateOutcome.Ok(new CreateResult(tx.Viewer.Currency.RedEther, allGrants));
     }
 
     public async Task<ProtectOutcome> SetProtected(long viewerId, long cardId, bool isProtected)