0xkaizendev/zkevm-call-forwarder

A cross chain forwarder that sends all calls to the sender's address on the other chain using zkEVM LxLy

LxLy Call Forwarder

This repo provides a smart contract implementation on how bridge messages to sender's address on the other network using PolygonZkEVM LxLy bridge

Note

Private keys and mnemonics contained in this repository are used for internal test exclusively. Do not use them in production environments

Requirements

• node version: 16.x
• npm version: 7.x

Repository structure

• contracts: zkevm contracts
  • PolygonZkEVMBridge.sol: transfer assets between chains
    • PolygonZkEVMGlobalExitRoot.sol: manage global exit root in L1
    • PolygonZkEVMGlobalExitRootL2.sol: manage global exit root in L2
  • PolygonZkEVM.sol: consensus algorithm used by polygon hermez zkevm
  • Sender.sol: bridge call to another chain using PolygonZkEVMBridge
  • CrossChainForwarder.sol: receive calls and forward them to sender's address
• test: contracts tests

Install

In project root execute:

npm i
cp .env.example .env

Run tests

npm run test

Deployment

Fill .env with your private key MAIN_ACCOUNT and ALCHEMY_KEY for every network. If you want to verify the contracts also fill the ETHERSCAN_API_KEY and POLYGONSCAN_API_KEY

To deploy use:deploy:sender:goerli for the sender and deploy:forwarder:goerli for the forwarder. These commands will deploy two identical instances of forwarder and sender contract on goerli and polygonZKEVMTestnet at the same address and this will replace existing addresses in ./deploy/sender.json and `./deploy/forwarder.json.

To verify contracts use npm run verify:sender:${network} and npm run verify:forwarder:${network} for each instance

npm run verify:sender:goerli
npm run verify:sender:polygonZKEVMTestnet
npm run verify:forwarder:goerli
npm run verify:forwarder:polygonZKEVMTestnet

Using the forward service

In order to use the forwarder, there are already provided some scripts:

• Send call using the command bellow, it will call bridgeMessage on PolygonZkEVMBridge from the origin network and bridge message to forwarder address on the other network. the call medata is supposed to call function setNumber of caller on the destination network and change the value. You can change favorite number value in ./scripts/bridge-call.js

npm run bridge:forwarder:goerli

• Now we have to wait until the message is forwarded to destination network, there's the final script that will check it and if it's ready will actually claim the call and forward it to sender address the other layer. the favoriteNumber of caller contract on destination network should be the same sent while bridging the call:

npm run claim:forwarder:polygonZKEVMTestnet

• The call forwarding can also be performed from L2 to L1, we just have to we just have to swap the network arguments when executing the last two commands.