Helpers

Check Transaction revert reason

Since Tenderly misses on traces with block.coinbaseuse https://tx.eth.samczsun.com/polygon/0x98798a8820fa01927c655a4223fd0f3821f7b013982e6d0d844c609237e2ef62 and click the little [call] to see the Output data and revert reason.

Check if time is right to attempt a bundle that can land.

Nodejs

const { ethers } = require('ethers');

const ALCHEMY_KEY = "alchemy-apikey";
const provider = new ethers.providers.AlchemyProvider("matic",ALCHEMY_KEY);


const getAuthor =  async(blockNum) => {
  const response = await fetch(`https://polygon-mainnet.g.alchemy.com/v2/${ALCHEMY_KEY}`, {
    method: 'POST',
    headers: {
      "Content-Type": "application/json",
    },
    body: JSON.stringify({
      "id": 1,
      "jsonrpc": "2.0",
      "method": "bor_getAuthor",
      "params": [
           '0x'+blockNum.toString(16)
      ]
 }),
  });
  const json = await response.json();
  return json.result;
}

let waitBlock = 0;
provider.on('block', async(block) => {
  try {
    console.log(block);
    if (block < waitBlock) return;
    const author = await getAuthor(block);
    console.log(author);
    const validators = [
      '0x127685D6dD6683085Da4B6a041eFcef1681E5C9C',
      '0x02f70172f7f490653665c9bfac0666147c8af1f5',
      '0xd2e4bE547B21E99A668f81EEcF0298471A19808f',
      '0xb9EDE6f94D192073D8eaF85f8db677133d483249',
      '0x9eaD03F7136Fc6b4bDb0780B00a1c14aE5A8B6d0',
    ].map(x => x.toLowerCase());
    if (author && validators.includes(author.toLowerCase())) {
      console.log('Validator active');
      // You should be able to submit bundles for a while
      await tryToSubmitBundlesForAFewBlocks();
      console.log('Closing');
      process.exit(0);
    } else {
      waitBlock = block + 10; // wait 10 more blocks
    }
  } catch (err) {
    console.error(err);
  }

});

List of validators active found in discord for now in #validators-list

Minimal Repayer

Substitutes a minimal Searcher Contract to receive a fastLaneCall and simply give back the _bidAmount to be sure the relay is repaid.

The FastlaneAuction handler will call this contract fastLaneCall if this contract address is submitted in the bundle as the searcherTx.

//SPDX-License-Identifier: Unlicensed
pragma solidity ^0.8.16;

// Example Contract that sends back _bidAmount to msg.sender
// It ignores _sender and _searcherCallData
// Used for testing purposes
contract SearcherHelperRepayerEcho {
    function fastLaneCall(
            address _sender,
            uint256 _bidAmount,
            bytes calldata _searcherCallData
    ) external payable returns (bool, bytes memory) {
        bool success;
        address to = msg.sender;
        assembly {
            // Transfer the ETH and store if it succeeded or not.
            success := call(gas(), to, _bidAmount, 0, 0, 0, 0)
        }

        require(success, "ETH_TRANSFER_FAILED");
        return (true,bytes("ok"));
    }
}