I can help you resolve the Universal Router for Ethereum (UR) rollback issue when selling tokens on the base network.
Introduction
The 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 result in transactions being rolled back if the contract on the external chain is not configured properly or if there is a problem with the transfer chain contract.
Rollback Issue
When a token sale uses the Universal Router and triggers a rollback from the base network to the target chain, it can result in a rollback error. This happens because:
- The rollback function of the base network contract expects a specific signature, but the transfer chain contract on the external chain requires a different signature.
- There is a problem with the transfer chain contract that prevents the transaction from being confirmed.
Refunding Problem Solution
To fix this issue, you will need to change your Ethereum-based contracts and update your universal router configuration accordingly. Here are some steps to follow:
1. Update the base network contract
In your base network contract, add a “refund” function that accepts a specific signature:
function withdraw(amount) {
//...
return { data: '0x...'}; // Replace with the current signature
}
Then update your code to call this function and fix any errors:
const { BigNumber } = require('bignumber.js');
const routerAbi = ...;
const baseNetworkContract = new Contract(baseNetworkAddress, routerAbi, 'BaseNetworkContract');
async function returnTokens() {
try {
const amount = await baseNetworkContract.withdraw(amount);
//...
} catch (error) {
console.error(error);
// Handle the error and try again
}
}
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
});
Be sure to replace the addresses and contracts with actual values.
3. Update the token sale contract
In the token sale contract, update the “withdraw” function to use the correct signature:
async function returnTokens() {
try {
const amount = await baseNetworkContract.withdraw(amount);
//...
} catch (error) {
console.error(error);
// Handle the error and try again
}
}
4. Update the transfer chain contract
If you are using a transfer chain contract, update its “withdraw” function to use the correct signature:
async function returnTokens() {
try {
const amount = await baseNetworkContract.withdraw(amount);
//...
} catch (error) {
console.error(error);
// Handle the error and try again
}
}
5. Test your code
After making these updates, thoroughly test your code to make sure that the refund issue is resolved.
Conclusion
The Universal Router for Ethereum dedicated router refund issue can be tricky to resolve, but by updating your contracts and configuration accordingly, you should be able to resolve the issue and successfully launch your token sale on the mainnet. Don’t forget to thoroughly test your code after making these updates to make sure that everything is working as expected.