Easiest Way To Use APIs In Unreal Engine For Beginners

Easiest Way To Use APIs In Unreal Engine For Beginners

Beginner-friendly guide to connect Unreal Engine 5.6 to any API with C++. Make async GET requests and call them in Blueprints using a simple function library.

This is Rambod, and in this guide I’ll show you the simplest way to connect Unreal Engine to any API without plugins or third-party tools.

We’ll write a single C++ file inside a Blueprint Function Library, set up Unreal’s built-in HTTP module, and create a Blueprint node that makes live GET requests.
By the end, you’ll have a working fetch data from URL node that prints real-time API data directly into your game.

1) Project Setup

👉 Any project works, but a clean C++ starter keeps things simple.

Editor Preferences

IDE

I’m using Rider Non-commercial Edition for Unreal.
If you want Rider setup instructions, check my Rider tutorial.

2) Create a Blueprint Function Library

  1. Go to Tools → New C++ Class.
  2. In the wizard, switch to All Classes.
  3. Search for Blueprint Function Library.
  4. Select it → Next → leave the class name (e.g. MyBlueprintFunctionLibrary).
  5. Click Create Class.

📌 Why Function Library?

3) Declare a Delegate & Static Function (Header File)

Open the generated .h file.

Step 1 – Add Delegate

At the top of the class, add:

// Delegate for API response
DECLARE_DYNAMIC_DELEGATE_TwoParams(FOnAPIResponse, int32, StatusCode, const FString&, Response);

This creates a Blueprint-friendly delegate that passes back:

Step 2 – Declare the Function

Inside public: section:

UFUNCTION(BlueprintCallable, Category="RambodDev|API")
static void FetchDataFromURL(const FString& URL, const FOnAPIResponse& Callback);

Key points:

4) Implement the Function (CPP File)

Right-click function name → Generate Definition in .cpp.

Includes

At the top of .cpp:

#include "HttpModule.h"
#include "Interfaces/IHttpResponse.h"
#include "Http.h"

Without these, Unreal won’t recognize HTTP types.

Function Logic

void UMyBlueprintFunctionLibrary::FetchDataFromURL(const FString& URL, const FOnAPIResponse& Callback)
{
    if (!FHttpModule::Get().IsHttpEnabled()) return;

    // Create request
    TSharedRef<IHttpRequest, ESPMode::ThreadSafe> Request = FHttpModule::Get().CreateRequest();
    Request->SetVerb("GET");
    Request->SetURL(URL);

    // Optional headers (e.g. JSON, API key)
    // Request->SetHeader(TEXT("Content-Type"), TEXT("application/json"));
    // Request->SetHeader(TEXT("Authorization"), TEXT("Bearer YOUR_API_KEY"));

    // Async response handler
    Request->OnProcessRequestComplete().BindLambda(
        [Callback](FHttpRequestPtr Request, FHttpResponsePtr Response, bool bSuccess)
        {
            int32 StatusCode = bSuccess && Response.IsValid() ? Response->GetResponseCode() : -1;
            FString Result = bSuccess && Response.IsValid() ? Response->GetContentAsString() : TEXT("Request failed");

            Callback.ExecuteIfBound(StatusCode, Result);
        }
    );

    Request->ProcessRequest();
}

✅ This creates a GET request, waits asynchronously, then triggers the delegate with results.

5) Update Build.cs

Inside Source/UnrealAPICallSample/UnrealAPICallSample.Build.cs:

PublicDependencyModuleNames.AddRange(
    new string[] { "Core", "CoreUObject", "Engine", "InputCore", "HTTP", "Json" }
);

👉 Without HTTP and Json, the project won’t compile.

6) Compile & Test

7) Testing the API Node in Blueprint

  1. Create a new empty level for testing.

  2. Open Level Blueprint.

  3. Add Event Begin Play.

  4. Search for your function: Fetch Data From URL.

  5. Connect Event Begin Play → Fetch Data From URL.

  6. URL: use a safe test endpoint:

    • https://jsonplaceholder.typicode.com/todos/1

  7. From the Callback pin → create Custom Event.

  8. Drag from Response → connect to Print String.

Now hit Play. 💡 You’ll see the live API JSON printed on screen.

Subtitle Expansion (Flow of Video)

“We’re connecting Unreal Engine 5.6 to any API using one simple setup. Start with a clean C++ project. Disable Live Coding under Editor Preferences for stability. Create a Blueprint Function Library class. Add a delegate with two params: StatusCode and Response. Declare a static FetchDataFromURL function with URL + Callback. In the CPP file, include HTTP headers. Inside, create an HTTP request, set verb to GET, pass the URL, optionally add headers for JSON or authentication. Bind a lambda to handle completion: check success, grab status code, grab content as string, then fire the delegate back to Blueprint. Don’t forget to add HTTP and Json to Build.cs dependencies. After building, open Unreal, make a test level, hook Event Begin Play to FetchDataFromURL, print the response in Blueprint. Hit Play—you’ll see live data printed from the API. This setup works for any endpoint and makes Blueprint API integration super easy. Advanced POST/DELETE/JSON parsing can be added later.”

8) Real-World Use Cases

Wrap-Up

We’ve built a beginner-friendly API integration:

👉 Watch the full tutorial: YouTube Link 👉 Sample Project: GitHub Repo 👉 Subscribe for more: Rambod Dev Channel