Copy the .env.example file to .env and fills with parameters. You can get EID for networks and endpoints here: https://docs.layerzero.network/v2/deployments/deployed-contracts
The "first network" is the one chosen when running the script with the following command:
npx hardhat run ./scripts/deployAndSetup.ts --network <network_name>
Where network_name is defined in hardhat.config.ts, for example amoy-testnet.
The script will deploy contracts on both chain (the second one is defined by the RPC url in .env) and run setup methods. Ensure to have enough gas on deployer keys on both networks.
To run a test that triggers a transfer from native chain to other chain and viceversa, fill the .env file with the deployed addresses logged by the above deploy script, and with a TEST_VALUE (in ETH) to transfer; then execute the following commands
-
Run from Native chain to second chain
npx hardhat run ./scripts/runTestNativeToOft.ts --network <network_name> -
Run from second chain to Native one
npx hardhat run ./scripts/runTestOftToNative.ts --network <network_name>
Between 1 and 2, wait some minutes to be sure LayerZero completed their transactions to mint the tokens on the second chain
The scripts will log all the sent transaction IDs. Ensure you have enough gas on both chain to perform operation. Also, on the "first chain" you will need enough value to fill the chosen TEST_VALUE. It is suggested to use TEST_VALUE >= 0.01 to avoid dust errors due to small amounts when using chains whose gas currencies have an high difference in price (i.e. Polygon and Ethereum).
Check the runTest scripts to see the needed methods to invoke to perform a transfer on both sides for a Front-End implementation.
npx hardhat run scripts/deployAndSetup.ts --network amoy-testnet
First Network: amoy-testnet
Deployer: 0xA89c7db6F4f3912674372Aaf7088b56d631301e6
Deployed contract: "MyNativeOFTAdapter", network: amoy-testnet, address: 0xa67A54C373101fDfF973900468926B27D0122FD8
Second Network RPC: https://sepolia.base.org
Deployer: 0xA89c7db6F4f3912674372Aaf7088b56d631301e6
Deployed contract: "MyOFT", network: https://sepolia.base.org, address: 0xf0833929536C3361fAb393837C297232D9B2248c
setup tx on first chain: 0x369612730dd5eb8d1d450e82d36b01936a355126faf840c3188703b939d46205
setup tx on second chain: 0x93e487c7a853f1b7bdcb95d6b4170a083734dfbe2474d6136ff7cf20e4b115ac
npx hardhat run ./scripts/runTestNativeToOft.ts --network amoy-testnet
Using contract: "MyNativeOFTAdapter", network: amoy-testnet, address: 0xa67A54C373101fDfF973900468926B27D0122FD8
sending value 10000000000000000 from native to oft
tx id: 0x32bffdb4de8af0e7eb74ad6d26c2ca389073db154637d41b75a14e1ae6e07692
npx hardhat run ./scripts/runTestOftToNative.ts --network amoy-testnet
Using contract: "MyOFT", network: https://sepolia.base.org, address: 0xf0833929536C3361fAb393837C297232D9B2248c
sending value 10000000000000000 from oft to native
tx id: 0x2ff8b969da3d87764145da7b196779ba6815371f3423e4db67108b80ce1b60fc
You also check the transactions and addresses on Scans:
- Contract on Polygon Amoy: 0xa67A54C373101fDfF973900468926B27D0122FD8
- Setup TX on Polygon Amoy: 0x369612730dd5eb8d1d450e82d36b01936a355126faf840c3188703b939d46205
- Contract on Base Sepolia: 0xf0833929536C3361fAb393837C297232D9B2248c
- Setup TX on Base Sepolia: 0x93e487c7a853f1b7bdcb95d6b4170a083734dfbe2474d6136ff7cf20e4b115ac
- Native Amoy -> Base Sepolia on Polygonscan: 0x32bffdb4de8af0e7eb74ad6d26c2ca389073db154637d41b75a14e1ae6e07692
- Native Amoy -> Base Sepolia on LayerZeroScan: https://testnet.layerzeroscan.com/tx/0x73a4be6f28fc5e112ca426f0fef3e23c4d2231854dee84997406a715c95b2739
- Base Sepolia -> Native Amoy on Basescan: 0x2ff8b969da3d87764145da7b196779ba6815371f3423e4db67108b80ce1b60fc
- Base Sepolia -> Native Amoy on LayerZeroScan: https://testnet.layerzeroscan.com/tx/0xe097fac41c5d986ce4546d237a526b876439b3757b33c37f17c7363835dc3f24
When running the first script, to transfer native POL from Polygon Amoy network to Base Sepolia network, the send method on the MyNativeOFTAdapter contract is invoked. In the parameters, the EID of the destination chain (Base Sepolia) is specified. Please note that there's no need to specify the destination address since it was already set in the setup phase with the setPeer method.
The transaction on Amoy Polygonscan:
This transaction transfers the POL tokens as value of the transaction: the transfered value is equal to the amount to transfer + the fee by the network. In this case we are transferring 0.01 POL, but the fee is very high due to the difference in price between Polygon Amoy and Base Sepolia. In fact, the value transferred here should also cover the fees that LayerZero nodes will pay to send the transaction on the destination chain. The paid fee is influcenced by the gas price on destination chain and also by the conversion rate of the involved gas-paying currencies (POL on Polygon, ETH on Base).
This Polygon transaction triggers a LayerZero transaction:
As we can see on LayerZero scan, the message payload contains both the destination address (0xA89c7db6F4f3912674372Aaf7088b56d631301e6, in the middle on the message without 0x and in lowercase) and the transfer value (at the end of the message).
Also, we see our Polygon transaction as Source Transaction Hash and a Base transaction in the Destination Transaction Hash
We can check on Sepolia Basescan what happened with the Destination Transaction:
As expected, the transaction minted 0.01 of the OFTT token (MyOFT contract instance) that was linked to the MyNativeOFTAdapter contract on Polygon.
When running the second script, to transfer OFTT token from Base Sepolia network to native POL in Polygon Amoy Network, the same send method is invoked, this time on the MyOFT contract deployed on Base Sepolia Network. Since on Base Sepolia this token exists as ERC20, it will be transferred internally in the method, while the value attached to the transaction is needed to cover the fees of the transaction that LayerZero will then run on the destination chain.
We can check the transaction on Sepolia Basescan:
As we can see, the transaction burned 0.01 OFTT from the sender account, since now they should not exist anymore on the Base Sepolia chain.
Searching the transaction on LayerZero Scan, we can see this:
Again, we see in the message payload the destination address and the value to transfer, and in the Destination Transaction Hash we have the hash of a Amoy Polygon transaction, that we can check in Polygonscan:
As expected, the transaction on Polygonscan shows that 0.01 POL (native) were sent to the destination address, completing the flow.