LayerZeroNFT

Omnichain Interoperable NFT

Hi,To start with, I will show you how to retrieve and update the project, then I will explain what all the folders mean, then I will show you the necessary configurations to do before deployment, and all the possible operations.

⚠️ All these infos are from the testnets, all that are in the constants folder and in the hardhat.config file

ethereum = rinkeby
polygon = mumbai
arbitrum = arbitrum rinkeby
optimism = optimism kovan
bsc = bsc testnet
avax = fuji testnet
fantom = fantom testnet

Start

First, you recover the project by making a git clone After recovering it, you make a cd LayerZeroNFT to enter the project directory and you make npm install to install all the dependencies

Folders

Constants Folder

• chainIds.json

it contains all the chains id of the different chains of layerZero LayerZero endpoints use a chainId to identify different blockchains. You can find them all here

• layerzeroEndpoints.json

it contains all the endpoint address of the different chains of layerZero You can find them all here

• layerZeroArgs.json

In this file you will find how your nfts are distributed on the different blockchains, you will see that the whole makes 1000, we have start and end ids on all blockchains. If you want to change them, make sure they respect the way I wrote them

• verifyContract.js

this file contains the arguments to make the verification of the contracts on the different blockchains, by using it, you will have to be sure that the arguments are the same as during the deployment otherwise the verification will not pass

Contracts Folder

in this folder is the contract You can check them out

Deploy Folder

This folder contains the deployment script

Tasks Folder

This folder contains all the scripts of operations that you will do, to test on the testnet but also on the mainnet, as for example the communication between the different blockchains, the addition of addresses to a whitelist, whitelistMint, the sending of nfts between the chains and others.

Test Folder

Nothing

Utils Folder

this folder contains a script to read the deployment folder that will be automatically created after the deployments

hardhat.config.js

this file contains all the configurations made to interact with the different blockchains, you will find their rpc url, their chain ids, their gas fee etc

Transactions

To start, create a file named .env in the root of the project in this file put this :

PRIVATE_KEY=your private key for deploy
PRIVATE_KEY2=your private key for test for example whitelist if you want
ETHER_API_KEY= your etherscan api key for verify contract on etherscan, its free to creating
POLYGON_API_KEY= your polygon api key for verify contract on polyscan, its free to creating
ARBITRUM_API_KEY=...
OPTIMISM_API_KEY=...

You can put all the different api keys of the different blockchains to use the script or you can do it directly on the browsers, up to you, I chose the first option

Don't forget to create a wallet especially for this and to put on this wallet all the funds on the different blockchains.

Testnet

You don't need to change anything to make the transactions on the testnet

Deploy

You have to change the first and the second argument which represent the metadatas, in deploy.js the first one corresponds to all the json files you have to put on ipfs, and the second one corresponds to a default json file for all the nfts minted before the reveal. For the second one, I created a default json file that I left on pinata. you can do the tests with

In the terminal, be sure to be in the project directory and to deploy on the 7 networks you must do.

npx hardhat --network ethereum deploy --tags LayerZeroNFT
npx hardhat --network arbitrum deploy --tags LayerZeroNFT
npx hardhat --network optimism deploy --tags LayerZeroNFT
npx hardhat --network polygon deploy --tags LayerZeroNFT
npx hardhat --network bsc deploy --tags LayerZeroNFT
npx hardhat --network avax deploy --tags LayerZeroNFT
npx hardhat --network fantom deploy --tags LayerZeroNFT

After the deployment a deployment folder will be automatically created in the root of your project.

Set Trusted Source

To enable communication between different blockchains, you need to do the following for all blockchains

• Ethereum communication

To allow communication between ethereum and other chains do :

npx hardhat --network ethereum LayerZeroNftSetTrustedSource --target-network arbitrum
npx hardhat --network ethereum LayerZeroNftSetTrustedSource --target-network optimism
npx hardhat --network ethereum LayerZeroNftSetTrustedSource --target-network polygon
npx hardhat --network ethereum LayerZeroNftSetTrustedSource --target-network bsc
npx hardhat --network ethereum LayerZeroNftSetTrustedSource --target-network avax
npx hardhat --network ethereum LayerZeroNftSetTrustedSource --target-network fantom

• Arbitrum communication

npx hardhat --network arbitrum LayerZeroNftSetTrustedSource --target-network ethereum
npx hardhat --network arbitrum LayerZeroNftSetTrustedSource --target-network optimism
npx hardhat --network arbitrum LayerZeroNftSetTrustedSource --target-network polygon
npx hardhat --network arbitrum LayerZeroNftSetTrustedSource --target-network bsc
npx hardhat --network arbitrum LayerZeroNftSetTrustedSource --target-network avax
npx hardhat --network arbitrum LayerZeroNftSetTrustedSource --target-network fantom

• Optimism communication

npx hardhat --network optimism LayerZeroNftSetTrustedSource --target-network ethereum
npx hardhat --network optimism LayerZeroNftSetTrustedSource --target-network arbitrum
npx hardhat --network optimism LayerZeroNftSetTrustedSource --target-network polygon
npx hardhat --network optimism LayerZeroNftSetTrustedSource --target-network bsc
npx hardhat --network optimism LayerZeroNftSetTrustedSource --target-network avax
npx hardhat --network optimism LayerZeroNftSetTrustedSource --target-network fantom

• Polygon communication

npx hardhat --network polygon LayerZeroNftSetTrustedSource --target-network ethereum
npx hardhat --network polygon LayerZeroNftSetTrustedSource --target-network arbitrum
npx hardhat --network polygon LayerZeroNftSetTrustedSource --target-network optimism
npx hardhat --network polygon LayerZeroNftSetTrustedSource --target-network bsc
npx hardhat --network polygon LayerZeroNftSetTrustedSource --target-network avax
npx hardhat --network polygon LayerZeroNftSetTrustedSource --target-network fantom

• Bsc communication

npx hardhat --network bsc LayerZeroNftSetTrustedSource --target-network ethereum
npx hardhat --network bsc LayerZeroNftSetTrustedSource --target-network arbitrum
npx hardhat --network bsc LayerZeroNftSetTrustedSource --target-network polygon
npx hardhat --network bsc LayerZeroNftSetTrustedSource --target-network optimism
npx hardhat --network bsc LayerZeroNftSetTrustedSource --target-network avax
npx hardhat --network bsc LayerZeroNftSetTrustedSource --target-network fantom

• Avax communication

npx hardhat --network avax LayerZeroNftSetTrustedSource --target-network ethereum
npx hardhat --network avax LayerZeroNftSetTrustedSource --target-network arbitrum
npx hardhat --network avax LayerZeroNftSetTrustedSource --target-network polygon
npx hardhat --network avax LayerZeroNftSetTrustedSource --target-network optimism
npx hardhat --network avax LayerZeroNftSetTrustedSource --target-network bsc
npx hardhat --network avax LayerZeroNftSetTrustedSource --target-network fantom

• Fantom communication

npx hardhat --network fantom LayerZeroNftSetTrustedSource --target-network ethereum
npx hardhat --network fantom LayerZeroNftSetTrustedSource --target-network arbitrum
npx hardhat --network fantom LayerZeroNftSetTrustedSource --target-network polygon
npx hardhat --network fantom LayerZeroNftSetTrustedSource --target-network optimism
npx hardhat --network fantom LayerZeroNftSetTrustedSource --target-network bsc
npx hardhat --network fantom LayerZeroNftSetTrustedSource --target-network avax

ok if you have no error it means that the communication between all blockchains is now good.

Start Public Mint

After your whitlisted users have made their mint, you can start the public mint by doing :

 npx hardhat --network avax startMint

Mint

You can test the mint by doing :

• on polygon

 npx hardhat --network polygon LayerZeroNftMint

• on arbitrum

 npx hardhat --network polygon LayerZeroNftMint 

• on ethereum

 npx hardhat --network ethereum LayerZeroNftMint 

and so on...

OpenSea view

you can see them on OpenSea testnet Copy and paste the address of your ethereum and polygon contract, so you will see your collection displayed on opensea, You can keep 2 tabs open in the browser for these 2 blockchains. We will test the sending between the chains.

Send nfts between different blockchains

as we have already posted our collection on opensea, we will test the sending between ethereum and polygon

for example to send a nft from ethereum to polygon make :

 npx hardhat --network ethereum LayerZeroNftSend --target-network polygon --token-id 1

be sure that the token id exists and that you put the right one look carefully at the id of the token you want to transfer to opensea

if all is well you can now see that your token which was on ethereum is now on polygon, you can see it on Opensea

Reveal

After mint you can reveal with

 npx hardhat --network ethereum reveal 

after the reveal if all your metadatas are near you can see them or if not you can metadatas with

Set base Uri

you can change your metadatas with the uri base, for that you have to put in parameter of the method setBaseURI that is in setBaseURI.js which is located in tasks

 npx hardhat --network ethereum setBaseURI 

Verify contrat

To check the contract, don't forget to:

• In the verifyContract.js file of the constants folder, put the same arguments as the one used during the deployment
• create the api keys on different explorers like etherscan, polyscan, arbiscan, snowtrace, etc...
• Put these keys in the .env environment variable as explained above.
• in hardhat.config.js configure the etherscan variable by replacing each time the apiKey by the one of the blockchain you want

For example verify ethereum contract make :

in hardhat.config.js :

 etherscan: {
    apiKey: process.env.ETHER_API_KEY,
  }

and make :

 npx hardhat verify --network ethereum --constructor-args constants/verifyContract.js addressofcontract

For polygon example

in hardhat.config.js :

 etherscan: {
    apiKey: process.env.POLYGON_API_KEY,
  }

and make :

 npx hardhat verify --network polygon --constructor-args constants/verifyContract.js addressofcontract

if all this is difficult for you, you can learn how to check contracts from blockchain explorers

Mainnet

To deploy on the mainnet, you must absolutely change :

• All the chains ids that are in chainIds.json with those of the mainnet : LayerZero mainnet ids

• All the endpoints that are in layerzeroEndpoints.json with those of the mainnet : LayerZero mainnet endpoints

• All networks config that are in hardhat.config.js (all url and chainId)

the transactions remain the same.

Thank you

Contact me if you have question.
Source : https://github.com/LayerZero-Labs/solidity-examples

🚀 🚀 🚀