UFUNCTION(Server, Reliable)
void Server_AddItem(UItemDataAsset* ItemData, int32 Quantity);

UFUNCTION(Server, Reliable)
void Server_RemoveItem(FName ItemID, int32 Quantity);

UFUNCTION(Server, Reliable)
void Server_MoveItem(int32 FromIndex, int32 ToIndex);

// Client predicts immediately
InventoryComponent->AddItem(ItemData, Quantity);

// Server validates
if (bServerValidated)
{
    // Success - client was correct
}
else
{
    // Rollback - server rejected
    InventoryComponent->RemoveItem(ItemData, Quantity);
}

TArray<FItemInstance> Overflow;
bool bSuccess = InventoryComponent->TryAddItemAtSlot(ItemInstance, -1, Overflow);

if (!bSuccess || Overflow.Num() > 0)
{
    // Not all items fit
    for (const FItemInstance& OverflowItem : Overflow)
    {
        // Drop in world
        InventoryComponent->SpawnWorldItem(OverflowItem, DropLocation);
    }
    ShowNotification("Inventory full - some items dropped");
}

// Check if target can accept item
FItemInstance ItemToTransfer = SourceInventory->GetItemAtIndex(SourceSlot);
if (TargetInventory->CanAddItemWeight(ItemToTransfer.ItemData, ItemToTransfer.Quantity))
{
    bool bSuccess = SourceInventory->TransferItem(SourceSlot, TargetInventory, -1, ItemToTransfer.Quantity);
    if (bSuccess)
    {
        ShowNotification("Item transferred");
    }
}
else
{
    ShowNotification("Target inventory too full");
}

// For crafting - consume multiple ingredients
bool bHasAll = true;
for (const FRecipeIngredient& Ingredient : Recipe->RequiredIngredients)
{
    int32 Available = InventoryComponent->GetItemCount(Ingredient.ItemData->ItemID);
    if (Available < Ingredient.Quantity)
    {
        bHasAll = false;
        break;
    }
}

if (bHasAll)
{
    // Consume all ingredients
    for (const FRecipeIngredient& Ingredient : Recipe->RequiredIngredients)
    {
        InventoryComponent->RemoveItemByAsset(Ingredient.ItemData, Ingredient.Quantity);
    }
    // Craft the item
}