C++ SDK Generator

The C++ SDK Generator lets you export your Blueprint public API as C++ headers, so other developers can reference your game's types and functions without needing your full source code.

What It Does

ModKit analyzes your Blueprint classes and generates:

• Public .h headers — function declarations, structs, enums
• Private .cpp stubs — empty implementations for compilation
• Module scaffolding — Build.cs, module registration files

The output is a standalone C++ module that modders can include in their mod projects.

Opening the Generator

From the Editor toolbar: ModKit → Generate C++ SDK

Generator Dialog

1. Select Blueprints — choose which Blueprint classes to export
2. Output Directory — where to write the generated headers
3. Module Name — name for the generated C++ module (e.g., MyGameSDK)
4. Click Generate

What Gets Exported

The generator analyzes each Blueprint and extracts:

• BlueprintCallable functions with their signatures
• BlueprintPure functions
• BlueprintImplementableEvent and BlueprintNativeEvent declarations
• Struct definitions (all fields)
• Enum values

Functions and properties marked as private or editor-only are excluded.

Example Output

For a Blueprint class BP_GameManager with a RegisterItem function, the generator produces:

// MyGameSDK/Public/BP_GameManager.h
// Auto-generated by ModKit C++ SDK Generator — do not edit
#pragma once

#include "CoreMinimal.h"
#include "UObject/Interface.h"
#include "BP_GameManager.generated.h"

UCLASS(BlueprintType)
class MYGAMESDK_API UBP_GameManager_SDK : public UObject
{
    GENERATED_BODY()

public:
    /** Register a new item with the game registry. */
    UFUNCTION(BlueprintCallable, Category = "Game|Items")
    static void RegisterItem(FName ItemId, UItemDefinition* Definition);

    /** Returns the current player count. */
    UFUNCTION(BlueprintPure, Category = "Game|Session")
    static int32 GetPlayerCount();
};

Distributing to Modders

After generating:

1. Zip the output directory
2. Upload it to your mod community (Discord, GitHub, itch.io)
3. Modders add the module as a dependency in their mod's Build.cs:

PublicDependencyModuleNames.AddRange(new string[] {
    "MyGameSDK",
    "ModKitCore",
});

IModKitGameInterface

Beyond the generated SDK, you can expose a custom game interface to C++ mods by implementing IModKitGameInterface in your game:

class MYGAME_API UMyGameInterface : public UObject, public IModKitGameInterface
{
    GENERATED_BODY()

public:
    virtual bool RegisterItem(const FName& ItemId, UObject* ItemData) override;
    virtual bool RegisterMap(const FName& MapId, const FSoftObjectPath& MapPath) override;
    virtual void LogModMessage(const FString& ModId, const FString& Message) override;
};

Register the instance before calling StartLoadMods() (which takes no arguments):

UMyGameInterface* GameInterface = NewObject<UMyGameInterface>();
ModLoader->SetGameInterface(GameInterface);
ModLoader->StartLoadMods();

note

The interface is delivered to C++ mods via IModKitMod::OnModLoaded(). C++ mod loading is not active yet (mods declaring native modules are rejected — see Security), so today the interface is mainly a forward-looking contract.

Keep It Minimal

Only expose what mods strictly need through IModKitGameInterface. The interface is your contract — every addition is a long-term commitment.