diff --git a/SVSim.EmulatedEntrypoint/Controllers/BuildDeckController.cs b/SVSim.EmulatedEntrypoint/Controllers/BuildDeckController.cs
index a42c156..1a795f3 100644
--- a/SVSim.EmulatedEntrypoint/Controllers/BuildDeckController.cs
+++ b/SVSim.EmulatedEntrypoint/Controllers/BuildDeckController.cs
@@ -171,8 +171,11 @@ public class BuildDeckController : SVSimController
         }
 
         // Open the inventory transaction — loads canonical graph + BuildDeckPurchases.
-        await using var tx = await _inv.BeginAsync(viewerId, HttpContext.RequestAborted,
-            cfg => cfg.WithInclude(v => v.BuildDeckPurchases));
+        await using var tx = await _inv.BeginAsync(viewerId, HttpContext.RequestAborted, cfg =>
+        {
+            cfg.Source = GrantSource.BuildDeckBuy;
+            cfg.WithInclude(v => v.BuildDeckPurchases);
+        });
         var viewer = tx.Viewer;
 
         // Debit currency