Recipes / Unreal Engine 5

Unreal Engine 5 C++ Integration

Submit scores and fetch leaderboards from UE5 using the built-in HTTP module — no third-party plugins required.

curlPhaserPixiJSGodotUnityUnreal

Prerequisites

  • Unreal Engine 5.x (C++ project)
  • A LightLeaderboard account, game, and API key
  • The HTTP module added to your .Build.cs
Blueprint support: The component below is marked BlueprintCallable — once you compile, you can call SubmitScore and GetLeaderboard directly from Blueprint nodes.

Step 1 — Enable the HTTP Module

Add "HTTP" to PublicDependencyModuleNames in your game's .Build.cs file.

MyGame.Build.cs C#
// MyGame.Build.cs — add "HTTP" to public dependencies
PublicDependencyModuleNames.AddRange(new string[] {
    "Core", "CoreUObject", "Engine", "InputCore",
    "HTTP", // <-- add this
});

Step 2 — Create the Component Header

A UActorComponent keeps the API logic self-contained and attachable to any Actor.

LeaderboardComponent.h C++
// LeaderboardComponent.h
#pragma once
#include "CoreMinimal.h"
#include "Components/ActorComponent.h"
#include "HttpModule.h"
#include "Interfaces/IHttpRequest.h"
#include "Interfaces/IHttpResponse.h"
#include "LeaderboardComponent.generated.h"

UCLASS(ClassGroup=(Custom), meta=(BlueprintSpawnableComponent))
class MYGAME_API ULeaderboardComponent : public UActorComponent
{
    GENERATED_BODY()
public:
    UFUNCTION(BlueprintCallable)
    void SubmitScore(int32 Score, FString PlayerId, FString PlayerName);

    UFUNCTION(BlueprintCallable)
    void GetLeaderboard(int32 Limit = 10);

private:
    static const FString ApiUrl;
    static const FString ApiKey;

    void OnScoreSubmitted(
        FHttpRequestPtr Req, FHttpResponsePtr Res, bool bSuccess);
    void OnLeaderboardReceived(
        FHttpRequestPtr Req, FHttpResponsePtr Res, bool bSuccess);
};

Step 3 — Implement in .cpp

Implement SubmitScore, GetLeaderboard, and their response callbacks.

LeaderboardComponent.cpp C++
// LeaderboardComponent.cpp
#include "LeaderboardComponent.h"

const FString ULeaderboardComponent::ApiUrl =
    TEXT("https://yourapp.com/api/v1/games/my_game");
const FString ULeaderboardComponent::ApiKey =
    TEXT("YOUR_API_KEY");

void ULeaderboardComponent::SubmitScore(
    int32 Score, FString PlayerId, FString PlayerName)
{
    auto Req = FHttpModule::Get().CreateRequest();
    Req->SetURL(ApiUrl + TEXT("/scores"));
    Req->SetVerb(TEXT("POST"));
    Req->SetHeader(TEXT("Authorization"), TEXT("Bearer ") + ApiKey);
    Req->SetHeader(TEXT("Content-Type"), TEXT("application/json"));

    FString Body = FString::Printf(TEXT(
        "{\"score\":%d,\"playerRefId\":\"%s\","
        "\"playerName\":\"%s\",\"submissionId\":\"%s\"}"),
        Score, *PlayerId, *PlayerName,
        *FGuid::NewGuid().ToString());

    Req->SetContentAsString(Body);
    Req->OnProcessRequestComplete().BindUObject(
        this, &ULeaderboardComponent::OnScoreSubmitted);
    Req->ProcessRequest();
}

void ULeaderboardComponent::OnScoreSubmitted(
    FHttpRequestPtr, FHttpResponsePtr Res, bool bSuccess)
{
    if (bSuccess && Res->GetResponseCode() == 200)
        UE_LOG(LogTemp, Log,
            TEXT("Score submitted: %s"), *Res->GetContentAsString());
}

void ULeaderboardComponent::GetLeaderboard(int32 Limit)
{
    auto Req = FHttpModule::Get().CreateRequest();
    Req->SetURL(ApiUrl +
        FString::Printf(TEXT("/leaderboard?limit=%d"), Limit));
    Req->SetVerb(TEXT("GET"));
    Req->SetHeader(TEXT("Authorization"), TEXT("Bearer ") + ApiKey);
    Req->OnProcessRequestComplete().BindUObject(
        this, &ULeaderboardComponent::OnLeaderboardReceived);
    Req->ProcessRequest();
}

void ULeaderboardComponent::OnLeaderboardReceived(
    FHttpRequestPtr, FHttpResponsePtr Res, bool bSuccess)
{
    if (bSuccess && Res->GetResponseCode() == 200)
        UE_LOG(LogTemp, Log,
            TEXT("Leaderboard: %s"), *Res->GetContentAsString());
        // parse JSON with TJsonReader or a plugin like VaRest
}

Tips

  • To parse the JSON response, use UE5's built-in TJsonReader / FJsonObject, or add the VaRest plugin for a Blueprint-friendly approach.
  • Store ApiKey in a config file (DefaultGame.ini) and load it with GConfig->GetString() rather than hardcoding in source.
  • The FGuid::NewGuid().ToString() call produces a unique submissionId per request — safe to retry on timeout.
  • Attach the component in Blueprint's Details panel or via CreateDefaultSubobject in your GameMode constructor.
← Unity C# All Recipes →