Shop Integration with Ultimate Multiplayer Lobby

Ultimate Multiplayer Lobby provides a simple and easy-to-use interface for integrating a shop system into your game. Let's set it up:

Steam Integration

Enable Inventory Service

To create a new store item, you need to follow these steps:

1. Open the Steamworks Developer site and log in with your Steam account.

2. On the Steamworks Developer site, click on Steamwork Settings and go to Inventory Service under Community. You can also use the following direct link but make sure to change your appid in the end of the link:

https://partner.steamgames.com/apps/inventoryservice/{appid} (opens in a new tab)

3. On the Inventory Service page, make sure to enable the Inventory Service for your game.

Create a New Store Item

Before creating a item, we need to get the ItemDef (opens in a new tab) schema ready. I am going to use a basic schema for this guide which I am sharing below.

Please note, this is the only way to get the item info right! All info like Images, Prices, Description go into this Json schema.

1. Create a new empty Json file and paste the ItemDef schema in it. I am sharing a basic schema below and if you are using the same, please make sure to change the appid and itemdefid as per your game.

Item10.json:

{
	"appid": 2056610,
	"items": [
	{
		"itemdefid": 10,
		"type": "item",
		"name": "Game Currency",
		"name_color":  "7D6D00",
		"price": "1;USD99",
		"background_color":  "3C352E",
		"item_slot": "Currency",
		"icon_url": "https://i.ibb.co/H7ypYhr/Achieved.jpg",
		"icon_url_large": "https://i.ibb.co/H7ypYhr/Achieved.jpg",
		"tradable": true,
		"marketable": true
	}]
}

2. On the Inventory Service page, upload the ItemDef schema file.

   

   Now reload the page and you will see the item you just created under the Item Definitions section.

   

Now, the items should show up in the shop in the game.

Epic Online Services Integration

Create an Offer

1. Go to the Offers section in the Epic Games Store publishing tools.

2. Click Create Offer and it should pop-up a window with the following fields:

• Offer Name: The name of the offer/item that you want to create.
• Offer Type: The type of offer you want to create. This can be a lot of things, like a demo, a special edition, a season pass, etc. We will be selecting Consumable for this example.

3. After the base offer is created, you have to configure the offer details. There are a lot of required fields:

These fields will be completely different depending on the type of offer you are creating. I will go ahead and quickly fill the fields for a consumable offer:

4. After you have filled all the required fields, click Save and your offer will be created. On the main offers page, you should see the offer with status as Ready for stage.

5. Now under the Release Management section, you can push the offer to the store by clicking Push to Stage.