Introduction to Epic Online Services (EOS)

Rajen Kishna, Technical Account Manager, Epic Games |
September 14, 2021
My name is Rajen Kishna and I’m a Technical Account Manager at Epic Games. In this series, I'll walk you through how to use Epic Online Services (EOS) to power your game with cross-platform authentication, voice chat, matchmaking, and more. The best part is that these services are all free to use, no matter where you choose to ship your game.

We’ll start with an overview of Epic Online Services and its components, and in subsequent articles we’ll build out a WPF demo app in C# that will show you how to use each individual service. You’ll find a continuously updated list of all articles in the series at the bottom of this post.

What is Epic Online Services (EOS)?

Epic Online Services (EOS) is a set of cross-platform gaming services to help game developers implement functionality like authentication, player progression tracking, matchmaking, voice chat, statistics, anti-cheat, and more. EOS is available anywhere, no matter what platform your game targets, which store you ship your game to, and which game engine you use. The back-end services powering this functionality are all fully hosted for you, so you won’t have to worry about infrastructure setup and maintenance, cost, or scale.

EOS can be roughly divided into three sets of services: account services—which provide Epic Account identity, friends, and presence, game services to cover multiplayer, progression, and game ops, and store services to manage Epic Games Store transactions. These services are all free to use for any developer.

These services can be accessed directly from your game using the SDK (available in C and C# across PC, iOS, Android, Playstation, Xbox, and Switch) and—for specific service calls—from your own back-end services through web APIs. Lastly, the SDK includes a few tools to help you implement and debug certain services.

Configuration of EOS is done through the Epic Games Developer Portal, which enables you to manage your organization (company) and products (games). In game, you can use the Epic Overlay to display UI to manage matchmaking and achievements. Here’s an overview of how all these components are interconnected:

EOS Marketecture Alt Blog 01 V3
Epic Online Services overview

Free, you say?

I mentioned above that the services and functionality offered with EOS is free to use and you may wonder “where’s the catch?”. The short answer is: there is no catch. These services were originally built for Fortnite and Epic now also uses them in the Epic Games Store. Now, Epic offers them to game developers for free with the goal of encouraging wider adoption of all of Epic’s offerings, and of making cross-play, cross-progression, and other open and interconnected, online features more accessible to everyone. If you’d like to learn more, check out the EOS FAQs here.

Now that we’ve gone through the overview of Epic Online Services, we can dive into setting up Epic Online Services in the Epic Games Developer Portal in the next article. Head over to the Epic Online Services Community Support forums to discuss this article, or post a new discussion to share feedback or if you run into issues implementing Epic Online Services.

    We succeed when you succeed

    Epic believes in an open, integrated games community. By offering our online services to everyone for free, we aim to empower more developers to serve their own player communities.