Quickstart_Cpp

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# C++ Quickstart

The following examples use the public Inventory Director headers and APIs. Include the concrete public headers used by the code in your module.

#include "InventoryComponent.h"
#include "InventorySubsystem.h"
#include "InventoryItemDefinition.h"

UInventoryComponent* Inventory = /* obtain the component */;
UInventoryItemDefinition* Potion = /* obtain a loaded definition */;

const int32 Count = Inventory->GetItemCount(Potion);
const FInventoryMutationResult Added = Inventory->AddItem(Potion, 2);
if (Added.IsChanged())
{
    const FInventoryMutationResult Removed = Inventory->RemoveItem(Potion, 1);
}

The native committed-change delegate is available through OnInventoryChanged():

Inventory->OnInventoryChanged().AddLambda(
    [](const FInventoryChangedEvent& Event)
    {
        // Read Event.InventoryIdentity, Event.Status, and Event.SlotChanges.
    });

The Game Instance subsystem provides identity lookup and transfer:

UInventorySubsystem* Subsystem = /* obtain the Game Instance subsystem */;
const FInventoryTargetIdentity Source = FInventoryTargetIdentity::MakePersistent(FName(TEXT("Player.Main")));
const FInventoryTargetIdentity Destination = FInventoryTargetIdentity::MakePersistent(FName(TEXT("Chest.Castle.Armory.03")));
const FInventoryMutationResult Transfer = Subsystem->TransferItem(Source, Destination, Potion, 1);

Pool selection uses the caller’s stream:

FRandomStream Stream(12345);
const FInventoryPoolSelectionResult Draw =
    Subsystem->SelectRandomItemFromPool(Pool, Stream);

Semantic persistence is independent of disk and slot orchestration:

FInventoryPersistenceSnapshot Snapshot;
const FInventoryPersistenceResult Captured =
    Subsystem->CapturePersistenceSnapshot(Snapshot);

if (Captured.IsSuccess())
{
    const FInventoryPersistenceResult Restored =
        Subsystem->RestorePersistenceSnapshot(Snapshot);
}

The exact subsystem acquisition mechanism depends on the owning Game Instance. Optional SaveGame adaptation is provided by DirectorBridge and does not change these core APIs.

For optional Probability-owned pool selection, use DirectorBridge’s Inventory.Probability integration and FDirectorBridgeInventoryProbabilityService::SelectPoolEntrySequential or SelectPoolEntryKeyed. The service receives the owning UGameInstance, Inventory-authored pool, Probability StreamId, and (for keyed calls) a stable DecisionKey. InventoryDirectorProbabilityBridge is retired. Inventory’s native FRandomStream pool APIs continue to work without DirectorBridge or Probability Director; see Probability Integration.

Runtime Inspector (V1.1)

During PIE/SIE open Tools → Director Suite → Runtime Inspectors → Inventory Director Runtime Inspector to inspect the selected authority; this surface is strictly read-only. Use Tools → Director Suite → Runtime Controls → Inventory Director Runtime Controls for explicit operations through the existing public component/subsystem APIs. Advanced Debug Override is unavailable because Inventory has no policy-only bypass. Controls do not write authored assets or save automatically. See Editor Tools for operation scope and journal behavior.