Skip to main content
Developers
Cross-Chain Messaging
Tutorials
Cross-Chain NFT

Build a cross-chain NFT

In this tutorial you will create an NFT collection with cross-chain transfer capabilities using Zeta Connector.

Cross-chain NFT transfer

Set up your environment​

git clone https://github.com/zeta-chain/template

Install the dependencies:

yarn add --dev @openzeppelin/contracts

Create a new contract​

To create a cross-chain NFT collection you will need to deploy NFT contracts implementing Zeta's interfaces and functions to multiple chains.

In a nutshell, your contracts will need to:

  • Implement a crossChainTransfer function, that burns the NFT on the current chain and uses zeta.send to send a message that mints it on the other one.
  • Implement onZetaMessage to mint the NFT that was burned on the other chain.
  • Implement onZetaRevert to handle crossChainTransfer errors, and re-mint the previously burned NFT.
contracts/CrossChainWarriors.sol
loading...

Create a deployment task​

The deploy task is almost exactly the same as the one used in the cross-chain messaging example. The only difference is that CrossChainWarriors' constructor function accepts one additional argument (useEven), which is used to prevent collisions between cross-chain token IDs. We're using true as a value for useEven in the factory.deploy function call.

The deploy task will deploy the CrossChainWarriors contract to two or more chains and set the interactors for all chains.

tasks/deploy.ts
loading...

Clear the cache and artifacts, then compile the contract:

npx hardhat compile --force

Run the following command to deploy the contract to two networks:

npx hardhat deploy --networks bsc-testnet,goerli
🚀 Successfully deployed contract on bsc-testnet.
📜 Contract address: 0x6Fd784c16219026Ab0349A1a8A6e99B6eE579C93

🚀 Successfully deployed contract on goerli.
📜 Contract address: 0xf1907bb130feb28D6e1305C53A4bfdb32140d8E6

🔗 Setting interactors for a contract on bsc-testnet
✅ Interactor address for 5 (goerli) is set to 0xf1907bb130feb28d6e1305c53a4bfdb32140d8e6

🔗 Setting interactors for a contract on goerli
✅ Interactor address for 97 (bsc-testnet) is set to 0x6fd784c16219026ab0349a1a8a6e99b6ee579c93

Create a mint task​

The mint task accepts a contract address as an argument, calls the mint function on it, searches the events for a "Transfer" event and prints out the token ID.

tasks/mint.ts
loading...
npx hardhat mint --network goerli --contract 0xFeAF74733B6f046F3d609e663F667Ba61B19A148

🔑 Using account: 0x2cD3D070aE1BD365909dD859d29F387AA96911e1

✅ "mint" transaction has been broadcasted to goerli
📝 Transaction hash: 0x48498d595f7aa5ab2c1569fe56b9861c4902a05420af2b7054008d1c283d8e40
🌠 Minted NFT ID: 12

Please, refer to ZetaChain's explorer for updates on the progress of the cross-chain transaction.

🌍 Explorer: https://explorer.zetachain.com/cc/tx/0x48498d595f7aa5ab2c1569fe56b9861c4902a05420af2b7054008d1c283d8e40

Create a transfer task​

The transfer task accepts the following arguments:

  • contract: the CrossChainWarriors contract address
  • address: recipient address
  • destination: destination chain ID
  • token: token ID
  • amount: amount of tokens to cover gas costs
tasks/transfer.ts
loading...
npx hardhat transfer --network goerli --contract 0xFeAF74733B6f046F3d609e663F667Ba61B19A148 --address 0x2cD3D070aE1BD365909dD859d29F387AA96911e1 --destination 97 --token 2 --amount 0.4

After the transfer transaction is confirmed, you will be able to see the NFT on the recipient address page on the destination chain (in this case, BSC).

Source Code​

You can find the source code for the example in this tutorial here:

https://github.com/zeta-chain/example-contracts/blob/feat/import-toolkit/messaging/warriors