Simple LayerZero Omni Chain Contracts

Install & Run tests

npm install
npx hardhat test 

OmnichainFungibleToken - Send Tokens to another chain

WARNING: YOU NEED TO PERFORM THE SET TRUSTED SOURCES STEP. Don't forget, nah you won't forget.

LayerZero Labs will publicize a new cross-chain token standard with permissive license soon

The OmnichainFungibleToken and OmnichainNonFungibleToken standardized libraries will have two varieties of deployments. Only one may be chosen:

1. Main chain & Child chain(s)
2. All Chain

In the Main chain & Child Chain variety, all tokens transferred out of the main chain will be locked (and minted on destination), and tokens transferred out of child chains will be burned (and minted on destination). This results in the Main Chain being like a home base. The initialy supply will only be minted entirely on the Main Chain on deployment. Our OmnichainFungibleToken example will follow the Main chain & Child Chain standardization.

In the All Chain implementation token transfers will always be burn & mint. The deployer may mint tokens in each deployment. Our OmnichainNonFungibleToken example will follow the All Chains standardization.

In the example deployment below, the default main chain is rinkeby. This setting is configured in constants/oftMainChain.json. The OmnichainFungibleToken deployed on other chains will use this configuration to set their main chain. Using the Ethereum network (testnet: rinkeby) as a source of truth is a security decision. In the event a chain goes rogue, Ethereum will be the final source of truth for OFT tokens. When sending tokens to other chains this contract locks the tokens on the main chain and mints on the destination chain. When other non-main chains send OFT's to each other they will burn and mint accordingly. When sending back to the main chain it will burn on the source chain and unlock on the main chain.

Are you down with OFT?

1. Deploy two contracts: rinkeby is the main chain

 npx hardhat --network rinkeby deploy --tags OmnichainFungibleToken
 npx hardhat --network fuji deploy --tags OmnichainFungibleToken

2. Set the trusted sources, so each contract can receive messages from one another, and only one another.

npx hardhat --network rinkeby omnichainFungibleTokenSetDestination --target-network fuji
npx hardhat --network fuji omnichainFungibleTokenSetDestination --target-network rinkeby

3. Send tokens across chains

npx hardhat --network rinkeby omnichainFungibleTokenSendTokens --target-network fuji --qty 250

Note: Remember to add a .env file with your MNEMONIC=""

OmnichainNonFungibleToken - Send an ONFT to another chain

WARNING: YOU NEED TO PERFORM THE SET TRUSTED SOURCES STEP.

In the All Chain implementation we deploy the contracts on the chains with a starting token id and max mint number. The key is to separate the token ids so no same token id can be minted on different chains. For our OmnichainNonFungibleToken example we deploy to two chains, bsc-testnet and fuji. We set the starting token id on bsc-testnet to 0 and max mint to 50. On fuji we set the starting token id to 50 and max mint to 100. This way no same token id can be minted on the same chain. These setting are configured in constants/onftArgs.json. When a transfer occurs between chains the ONFT will be burned on the source chain and minted on the destination chain.

Go Omnichain: Be the Deployooooor

1. Deploy two contracts:

 npx hardhat --network bsc-testnet deploy --tags OmnichainNonFungibleToken
 npx hardhat --network fuji deploy --tags OmnichainNonFungibleToken

2. Set the trusted sources, so each contract can receive messages from one another, and only one another.

 npx hardhat --network bsc-testnet omnichainNonFungibleTokenSetTrustedSource --target-network fuji
 npx hardhat --network fuji omnichainNonFungibleTokenSetTrustedSource --target-network bsc-testnet

3. Mint your ONFT on each chain!

 npx hardhat --network bsc-testnet omnichainNonFungibleTokenMint
 npx hardhat --network fuji omnichainNonFungibleTokenMint

4. Verify you are the owner of that token on that chain

 npx hardhat --network bsc-testnet  omnichainNonFungibleTokenOwnerOf --token-id 1
 npx hardhat --network fuji omnichainNonFungibleTokenOwnerOf --token-id 51

5. Send ONFT's across chains

npx hardhat --network bsc-testnet omnichainNonFungibleTokenTransfer --target-network fuji --token-id 1

6. Verify your token no longer exists on the source chain

 npx hardhat --network bsc-testnet  omnichainNonFungibleTokenOwnerOf --token-id 1

7. Lastly verify your token exist on the destination chain

npx hardhat --network fuji  omnichainNonFungibleTokenOwnerOf --token-id 1

Note: Remember to add a .env file with your MNEMONIC=""

Testing Cross Chain Messages

1. Deploy both OmniCounters:

npx hardhat --network bsc-testnet deploy --tags OmniCounter
npx hardhat --network fuji deploy --tags OmniCounter

2. Set the remote addresses, so each contract can receive messages

npx hardhat --network bsc-testnet omniCounterSetDestination --target-network fuji
npx hardhat --network fuji omniCounterSetDestination --target-network bsc-testnet

3. Send a cross chain message from bsc-testnet to fuji !

npx hardhat --network bsc-testnet omniCounterIncrementCounter --target-network fuji

Optionally use this command in a separate terminal to watch the counter increment in real-time.

npx hardhat --network fuji omniCounterPoll    

Testing Multiple Cross Chain Messages

1. Deploy both OmniCounters:

npx hardhat --network bsc-testnet deploy --tags OmniCounter
npx hardhat --network fuji deploy --tags OmniCounter
npx hardhat --network mumbai deploy --tags OmniCounter
npx hardhat --network fantom-testnet deploy --tags OmniCounter

2. Set the remote addresses, so each contract can receive messages

npx hardhat --network bsc-testnet omniCounterSetDestination --target-network fuji
npx hardhat --network fuji omniCounterSetDestination --target-network bsc-testnet

npx hardhat --network bsc-testnet omniCounterSetDestination --target-network mumbai
npx hardhat --network mumbai omniCounterSetDestination --target-network bsc-testnet

npx hardhat --network bsc-testnet omniCounterSetDestination --target-network fantom-testnet
npx hardhat --network fantom-testnet omniCounterSetDestination --target-network bsc-testnet

3. Send a cross chain message from bsc-testnet to fuji,mumbai,fantom-testnet !

npx hardhat --network bsc-testnet omniCounterIncrementMultiCounter --target-networks fuji,mumbai,fantom-testnet

Optionally use this command in a separate terminal to watch the counter increment in real-time.

npx hardhat --network fuji omniCounterPoll
npx hardhat --network mumbai omniCounterPoll
npx hardhat --network fantom-testnet omniCounterPoll

Getting and Setting the Oracle

Read the currently set Oracle

npx hardhat --network bsc-testnet omniCounterGetOracle --target-network fantom-testnet

Set a custom Oracle for the deployed OmniCounter

npx hardhat --network bsc-testnet omniCounterSetOracle --target-network fantom-testnet --oracle 0x000000000000000000000000000000000000dEaD

See some examples in /contracts 🙌

Many of the example contracts make use of LayerZeroEndpointMock.sol which is a nice way to test LayerZero locally!

For further reading, and a list of endpoint ids and deployed LayerZero contract addresses please take a look at the Gitbook here: https://layerzero.gitbook.io/

Most recently tested with node version 16.13.1