Ethereum: How to solve the universal router return problem?

I can walk you through the process of fixing the Universal Router for Ethereum (UR) rollback issue with a token sale on the base network.

Introduction

Universal Router is a decentralized bridge that allows you to use external chains, such as Binance Smart Chain or Optimism, to initiate token sales on the main network. However, this can lead to transaction rollbacks if the contract on the external chain is not configured correctly or if the relay chain contract has issues.

The Rollback Issue

When a token sale uses Universal Router and triggers a withdrawal from the base network to the target chain, it can cause a rollback error. This occurs because:

• The withdrawal function in the base network contract expects a specific signature, but the relay chain contract on the external chain provides a different signature.

• The relay chain contract has an issue that prevents the transaction from being confirmed.

Solving the rollback issue

To fix this issue, you will need to modify your Ethereum-based contracts and update your Universal Router configuration accordingly. Here are some steps to take:

1. Update the base network contract

In the base network contract, add a withdraw function that accepts a specific signature:

function withdraw(amount) {
// ...
return { data: '0x...'}; // Replace with the actual signature
}

Then, update your code to call this function and handle any errors:

const { BigNumber } = require('bignumber.js');
const routerAbi = ...;
const baseNetworkContract = new Contract(baseNetworkAddress, routerAbi, 'BaseNetworkContract');
async function withdrawTokens() {
try {
const amount = await baseNetworkContract.withdraw(amount);
// ...
} catch (error) {
console.error(error);
// Handle the error and retry
}
}

2. Update the Universal Router configuration

In the Universal Router configuration, update the relayChain settings to point to the correct contract on the target chain:

const universalRouter = new UniversalRouter({
baseNetworkAddress: '0x...', // Base network address
relayChainAddress: '0x...', // Target chain address
relayChainContract: 'RelayChainContract', // Relay chain contract ABI
});

Make sure to replace the addresses and contracts with their actual values.

3. Update the token sale contract

In the token sale contract, update the withdraw function to use the correct signature:

async function withdrawTokens() {
try {
const amount = await baseNetworkContract.withdraw(amount);
// ...
} catch (error) {
console.error(error);
// Handle the error and retry
}
}

4. Update the relay chain contract

If you are using a relay chain contract, update your withdraw function to use the correct signature:

async function withdrawTokens() {
try {
const amount = await baseNetworkContract.withdraw(amount);
// ...
} catch (error) {
console.error(error);
// Handle the error and retry
}
}

5. Test your code

After making these updates, test your code thoroughly to ensure that the rollback issue is resolved.

Conclusion

Fixing the rollback issue on Universal Router for Ethereum can be challenging, but by updating your contracts and configuration accordingly, you should be able to resolve this issue and successfully launch a token sale on the base network. Remember to test your code thoroughly after making these updates to ensure everything works as expected.