Unreal Engine

The mod.io Unreal Engine Plugin suite helps you integrate user-generated content (UGC) into Unreal Engine 5 projects.

At its core, the Unreal Engine plugin is a wrapper around the mod.io C++ SDK, exposing an Unreal-friendly API (including Blueprint support) for common mod.io workflows:

• Connecting your title to mod.io (initialization + shutdown)
• User authentication and local sessions
• Browsing, searching, and filtering UGC
• Subscribing and managing local UGC (downloads, installs, updates, removals)

Most of the Core Plugin surface area lives on UModioSubsystem. If you want to understand what functions are available and how callbacks are shaped, the Reference Docs are the canonical index.

Core Plugin

Facilitates core mod.io service functionality, such as authentication, filtering and subscription management.

ModioUGC

An opinionated modding framework that supports cooking UGC, loading PAK files, and content loading.

Features

Explore a variety of customizable offerings that work alongside the UE Plugin to enhance UGC in your game.

Legacy

For games operating on Unreal Engine 4, our Legacy Plugin supports core mod.io functionality for UGC.

You can download the Unreal Engine Plugin from GitHub. If you're new to the plugin, start with the Getting Started overview for the recommended learning path.

Connecting your game to mod.io

To connect your Unreal Engine project to mod.io, you will need to create a game profile in the mod.io dashboard. This is where mod.io hosts your UGC and where you configure features your game uses.

At a high level, your integration requires:

• A mod.io Game ID identifying your game
• An API key used to authenticate requests for that game
• The correct environment (Test or Live)
• The correct portal (storefront/platform) for platform-compliant user identity and display

In the Unreal Engine plugin, these values are typically supplied via the plugin's Project Settings (see Installation) and used to build the ModioInitializeOptions you pass to InitializeAsync.

note

mod.io provides a sandbox environment (test.mod.io) for development and QA. The plugin supports this via the environment value you pass during initialization.

How the plugin wraps the SDK

If you're familiar with the mod.io C++ SDK, the Unreal plugin will feel very similar:

• SDK calls are exposed as methods on UModioSubsystem rather than free functions in the Modio namespace
• The interface is non-blocking and callback-based; async operations complete via delegates
• Work completes when the plugin event loop is ticked via RunPendingHandlers

You can tick the event loop manually (for example, once per frame), or enable the background thread option in Project Settings to have the plugin maintain the event loop for you. See Initialization and Structure & Error Handling for details.

Engine compatibility

The mod.io plugin is generally maintained to support the 3 most recent versions of Unreal Engine, in line with the engine support policy of Epic. If you are using an older version of the engine, you can access the last supported release of the engine from our releases page on GitHub.

Engine Version	Last Release
UE4.26	2023.11
UE4.27	2023.11
UE5.0	2023.11
UE5.1	2024.6
UE5.2	2025.2
UE5.3	2025.9
UE5.4	2026.3
UE5.5	Current
UE5.6	Current
UE5.7	Current

Getting started

Start with the Getting Started overview. It links to the full guide series (installation, initialization, authentication, and core UGC workflows) in the recommended order.

Feature Guides

The Unreal Plugin is compatible with a variety of mod.io's features. These are additions to the core plugin that are designed to streamline and elevate your game's UGC. Check out the Feature Guides for Unreal Engine.

Sample Project

mod.io also provides a sample project, featuring a full integration of the Core Plugin, ModioUGC and our UI products including a custom UI build with ComponentUI and Template UI. This sample is based off Epic's Action RPG sample, and demonstrates best practice UGC loading functionality. You can find out more about the ActionRPG sample here.