Build a cross-chain NFT marketplace

Tasks

1. Build and deploy an NFT marketplace

2. Create a template for cross-chain NFT referencing

3. Submit the template as an ICON Improvement Proposal (IIP)

Rewards

Tokens / Winner	Bonus	Winners	Notes
40,000	40,000 HVH for HAVAH winner. 20,000 HVH for other winners if the dApp connects to HAVAH chain	3	1 EVM ↔ EVM, 1 EVM ↔ ICON-Java

Evaluation Criteria

Unique to xCall — new use cases unlocked by xCall’s distinct new features (i.e. interoperability)
Functionality — deployed and workable on xCall-connected-networks
Implementation — quality, readable, clean code
Impact — open-sourced, publicly available code via Github and the ICON IIP repository
Sustainability — extensible and a realistic path to continue development
Originality — should be an original creation. If based on an open-source code, needs to contain clear improvements on the original (and comply with applicable licenses)
Cross-chain integrations — priority given to solutions that integrate as many chains as possible. Heterogeneous solutions like EVM ↔ ICON-Java are great! So are innovative solutions involving multiple EVM chains!
Leverage ecosystem tooling — Use development-assist tools like Drogon, ICON Tracker API, ICON SDKs, javaee-scorex, javaee-annotation-processor, javaee-unittest, Hana wallet, etc. See the awesome-icon list for tools in the ecosystem

One winner will be awarded for a dApp between EVM ↔ EVM environments, one winner will be awarded for a dApp between EVM ↔ ICON-Java environments, and one winner using the HAVAH chain

How to Submit

Please fill out this submission challenge form, selecting the relevant task

Instructions

Create a basic NFT marketplace using xCall. This entails the marketplace smart contracts and front-end that will allow users to buy, sell, and trade NFT tokens in exchange for fungible tokens

Key features include a generic NFT marketplace smart contract, listing NFT tokens for sale for any fungible token, buying NFT tokens with fungible tokens, trading any NFT token with any other NFT, and any additional marketplace capabilities you’re keen to experiment with (auctions, fractionalization, royalties, etc.)

Focus mostly on the backend contracts, as this will be given more consideration during judging. Although, it will be necessary to verify the NFT-backed assets that are transferred or purchased across chains