Build your first signal.
Then build a system around it.

Create one typed Blueprint event and see it travel from a producer to a listener.

1. Install and enable.

   Copy the plugin to <Project>/Plugins/RekallGlobalEvents, or to <UE_5.8>/Engine/Plugins/Marketplace/RekallGlobalEvents for every project using that engine. Enable Rekall Global Events and restart. Blueprint-only projects need no Visual Studio generation or module dependency.

2. Create the payload.

   In the Content Browser, choose Add > Blueprint > Structure. Name it ST_InventoryItemAdded and add the fields your listeners need.

3. Create the definition.

   Choose Add > Data > Data Asset, select Rekall Event Definition, give it the tag Event.Inventory.ItemAdded, and select your Blueprint Struct as its payload.

4. Build a catalog.

   Repeat Add > Data > Data Asset, select Rekall Event Catalog, add the definition, then assign it under Project Settings > Game > Rekall Events.

5. Publish and listen.

   Place Publish Inventory Item Added and Bind Inventory Item Added. Their payload pins are the exact ST_InventoryItemAdded type.

Definition-backed K2 nodes give designers a familiar node workflow without sacrificing the event’s exact payload contract.

Blueprint Struct
  → Rekall Event Definition
    → Rekall Event Catalog
      → Publish / Bind / Wait / Query / Replay

The typed facade resolves a definition once, enforces the payload type, and keeps the routing implementation out of gameplay code.

USTRUCT(BlueprintType)
struct FInventoryItemAdded
{
    GENERATED_BODY()

    UPROPERTY(EditAnywhere, BlueprintReadWrite, Category="Inventory")
    TObjectPtr<UObject> Item = nullptr;

    UPROPERTY(EditAnywhere, BlueprintReadWrite, Category="Inventory")
    int32 Quantity = 0;
};

TRekallEvent<FInventoryItemAdded> Event =
    Rekall::Events::Resolve<FInventoryItemAdded>(World, EventTag);

FRekallScopedSubscription Subscription = Event.Subscribe(
    Owner,
    [](const FInventoryItemAdded& Payload,
       const FRekallEventContext& Context)
    {
        // Exact payload. Read-only delivery context.
    });

Event.Publish(FInventoryItemAdded{ Item, 1 });

The scoped subscription is move-only and removes its handle on reset or destruction. UObject owners are weak. Off-thread ordinary API calls reject without touching UObject state; certified POD events can use the dedicated bounded worker handoff.

Event definitions own defaults. Publication options override scope, delivery mode, tick phase, or priority only when their corresponding override flag is set. Selectors and parent correlation remain publication-owned.

The Network module transports approved Core events. It never turns a client-supplied tag into trusted authority.

Admission sequence

1. Resolve the registered player-owned endpoint.
2. Resolve the live Core definition on authority.
3. Validate route direction and Network policy.
4. Validate payload schema and configured readiness.
5. Consume rate and byte budgets.
6. Publish locally or fan out to Owner, Audience, or All.

Flow Assets compile authored graphs into immutable plans. Invalid types, missing extensions, unreachable nodes, unbounded cycles, and authority mismatches fail validation before runtime.

Project Settings > Game > Rekall Flow caps active instances, runtime bytes, World steps per frame, and terminal history. Each instance cleans subscriptions, timers, child flows, and extension handles on every terminal path.

Register an event trace sink or enable the RekallEvents Unreal Trace channel. The optional Insights module merges Core stages, network hops and authorization outcomes, and Flow transitions into a bounded timeline.

• Attempt sequence follows one logical publication across worker handoff and router stages.
• Delivery sequence is router-local and preserves dispatch ordering.
• Correlation and parent correlation connect nested publications.
• Payload capture requires definition permission, Full policy, sampling, and consumer interest.
• Payload text is bounded and sanitized; raw reflected values are never retained by the trace record.

The installed customer package contains exactly five customer modules:

Core does not depend on Network, Flow, Insights, Slate, BlueprintGraph, KismetCompiler, or UnrealEd. Network and Flow depend one-way on Core. Editor and Insights are available for authoring and diagnostics, but they do not enter packaged Game, Client, or Server runtime receipts. Tests, QA tags, and docs-test modules are not delivered.

1. Confirm the definition asset is saved and belongs to the configured catalog.
2. Confirm the payload is the exact struct declared by the definition.
3. Inspect the structured result’s status and diagnostic code.
4. Check the event’s effective scope, delivery defaults, selectors, and authority.
5. Enable Rekall Insights or the trace channel for correlation-level evidence.
6. For packaged builds, confirm Core plus any intentionally used Network/Flow modules are enabled.

Rekall Global Events 1.0.0 has passed clean-project qualification on UE 5.8 and Win64. Legal Publisher: Rekall Software Solutions / Marius Myburg. Final Marketplace support URLs, license selection, and account verification are completed during submission.