Create, cancel and fill orders in Unreal

In this tutorial step, you will learn how to create, cancel, and fill orders in the Unreal marketplace as well as displaying NFTs in your Unreal game.

This is the core functionality required to create and in-game market experience for your players.

💡Prerequisite step

Before continuing with this step, ensure you have completed the getting started building a marketplace in Unreal step.

Sample app overview

The core NFT functionalities—including buying, listing, and canceling listings—are primarily implemented in C++. Key classes such as UMarketplacePolicy and UCustomLocalPlayer, along with widget classes located in the Marketplace and Inventory folders, provide the foundational structure for these features. To create a customized in-game marketplace, review the following essential files closely:

• USearchStacksWidget
• USearchStacksOptionWidget
• USearchStacksListingWidget
• USearchNfTsWidget

These files contain the critical elements needed to understand and modify marketplace interactions and NFT handling within the game. For further explanation of the various request/response workflows see the relevant sections below.

Displaying NFTs

To display purchasable and player-owned NFTs, refer to the marketplace and inventory code snippets. These snippets provide examples of how to integrate NFT display functionality into your Unreal game, ensuring a seamless in-game marketplace experience.

Marketplace Functionality

This section provides a detailed breakdown of the underlying request/response workflows for the core marketplace functionalities. To better visualize these processes, we have included sequence diagrams that illustrate the interactions between the Unreal SDK, the Immutable APIs, and the zkEVM blockchain.

By understanding these workflows, developers can:

• Gain insights into the marketplace's inner workings.
• Troubleshoot potential issues more effectively.
• Implement similar functionalities in their own projects.

These diagrams serve as valuable references for developers wishing to replicate or customize the marketplace features.

Listing NFTs

The diagram below illustrates the workflow for creating a listing in the in-game marketplace.

Canceling Listings

The diagram below illustrates the workflow for canceling a listing in the in-game marketplace.

Fulfilling Buy Orders

The diagram below illustrates the workflow for fulfilling an order in the in-game marketplace.

Next steps

Once you've reviewed the linked sample app files and understood the workflows, you should have all the knowledge you need to build your in-game marketplace experience in Unreal. If you need help with troubleshooting or additional resources click next below.