7
votes
Accepted
What prevents miners from cooperating and causing intentional chain reorgs?
Nothing prevents collusion
From former Bitcoin Core developer Greg Maxwell https://old.reddit.com/r/Bitcoin/comments/ddddfl/question_on_the_vulnerability_of_bitcoin/f2g9e7b
The attack would work just ...
eth♦
- 86.5k
4
votes
How to create and send Flashbot transactions?
The official flashbots searcher onboarding guide is a good source to get started.
block.coinbase in Solidity refers to the miner of the current block. You can use the ethers.js flashbots bundle ...
- 945
4
votes
Accepted
How to Tranfer Remaining NFTs And/Or Tokens Out of A Hacked Ethereum Wallet
You are in the correct path. MEV can do this for you.
You can use MEV to submit two transactions with the following properties:
Either both or none of them go through
They should be executed in the ...
- 30.2k
3
votes
How to Tranfer Remaining NFTs And/Or Tokens Out of A Hacked Ethereum Wallet
I was in the same situation - my credentials were stolen when i connected metamask to scam website that looked like legit one. ETH scavenger was eating all my ETH in wallet and my NFTs were stuck in ...
- 31
3
votes
Flashbots error unable to decode txn
I encountered the same problem just now.
The solution was to add the chainId in each TransactionRequest object of your bundleTransactions.
The github example doesn't include the chain id in each ...
- 31
3
votes
How to conduct a flash loan on PancakeSwap?
PancakeSwap is a fork of Uniswap V2, which allows flashswaps. An example of flashswap using Uniswap V2 can be found here: https://github.com/Uniswap/uniswap-v2-periphery/blob/master/contracts/examples/...
3
votes
Accepted
What decides the order of transactions in a block?
It depends, really. Some miners on the Ethereum chain, like Ethermine, use non-conventional ordering for their benefit, aka they generally don't do the by-gas sort. Other miners can choose to sort by ...
- 751
3
votes
What prevents miners from cooperating and causing intentional chain reorgs?
As Mikko mentioned, it would be super difficult for them to start cooperating in such a way. If their miners find out, they can just easily switch to an "honest" pool.
But assuming that ...
- 30.2k
2
votes
Accepted
Can a flash loan used to flash attack a smart contract?
Yes, it is possible.
Moreover that technique was already used against MakerDao, read https://forum.makerdao.com/t/urgent-flash-loans-and-securing-the-maker-protocol/4901.
It can be fixed by requiring ...
- 30.3k
2
votes
What decides about the position in the block?
If you search this site there are multiple questions which ask the same thing but from a bit different angle, so I couldn't find an exact duplicate for your questions, although my answer has all the ...
- 30.2k
2
votes
How are 0 gas price transactions getting mined?
The simplest answer is that the miner was paid (0.011111111111111 Ether) in the next transaction.
Brief details
This worked because a specific miner was sent 2 transactions off-chain.
The transaction ...
eth♦
- 86.5k
2
votes
What decides the order of transactions in a block?
The order of transactions (we are talking about transactions with the best gas price) is decided by the miners to make the most profit out for them. To find out more about the subject google keywords ...
- 4,116
2
votes
How do frontrunners / sandwich bots work? How do they affect the price in the pool?
TL;DR Sandwich bots work by having a buy transaction before the victim's buy transaction, then a sell transaction just after. They profit from the increase of price caused by the victim's buy ...
- 3,630
2
votes
Flashbot Private Transaction
You are correct, private transactions are sent directly to the miner, bypassing the public mempool.
There are a few very good reasons to go directly to the miner:
Protect yourself from frontrunning, ...
- 317
2
votes
How fast are liquidation bots?
I am usually able to get the liquidation in the block after the oracle update is written on chain from Chainlink.
By checking once per second you could query multiple times for the same block, and ...
- 51
2
votes
High Gas Flashbots Transaction
The reason for this is generally the last transaction in the bundle is the one that pays the miner tip.
Basically, anything in excess of the required gas goes to the miner. It's weird now that Type 2 ...
- 51
2
votes
Flashbots Inclusion of a Mempool Signed Transaction
I found the solution. So i ever someone else is having the same issue, you need to get the raw tx before trying to serialize.
That was all :)
- 21
2
votes
Accepted
Help me make sense of this seeminlgly simple Uniswap V2 transaction, please
Ok so I think I figured it out, studying the token's source code, this is a common scheme to "cash out" taxes/fees charged on every token trade or transfer.
What are taxes/fees? Taxes/fees ...
- 193
2
votes
Accepted
WETH tokens burned after Single Swap
My guess is that there is a bot that scans contracts that have no access controls and tries to exploit them. I was able to get around this by making my contract Ownable and changing the withdrawAll ...
- 31
1
vote
How to fastest send Flashbot transaction?
Is there a way to confirm Flashbot transaction in now_block_numer + 1 block?
No
- 23k
1
vote
How to send bundles directly to top MEV builders?
Checkout https://www.mev.to/builders/ for a list of top builders on mainnet. All of these builders support eth_sendBundle call to receive MEV transactions.
- 36
1
vote
Is mev-geth analougue to geth?
Geth and mev-geth are both Ethereum node implementations, but mev-geth is a fork of Geth created by Flashbots with additional functionality for detecting and mitigating frontrunning, a type of attack ...
- 686
1
vote
Understanding eth_sendBundle, eth_sendPrivateTransaction and eth_sendRawTransaction
eth_sendPrivateTransaction basically a simplified way of using eth_sendBundle. You don't have to add more transactions than 1 and you don't have to resend the transaction every block. They will send ...
- 11
1
vote
Flash Loan Transaction
You need to deploy a proxy contract to make the transaction atomically for you. And you need to revert the transaction if there isn't any profit. See my example:
function arbitrage(address routerA, ...
- 784
1
vote
Accepted
Getting empty result from eth_sendBundle on builder0x69
It seems that eth_sendBundle works just fine despite returning an empty result field in the RPC response. It also does not support eth_callBundle to simulate bundle execution at the time.
- 494
1
vote
How to see if a tx was private using web3.eth.getTransaction?
You can't.
Etherscan achieves this by ordering all the transactions within that block by the gas price, if the order of the transaction (by index) does not match the order by the gas price (descending)...
- 23
1
vote
Accepted
Transaction failing but I'm unsure why
When I trace the transaction it has 0 gas left on UniswapV2Pair.sol:185
"gas":{
"gas_left":0
"gas_used":0
"total_gas_used":1000000
}
You need to pay way more ...
- 26
1
vote
Accepted
High Gas Flashbots Transaction
As you already mentioned I found the solution in the following paper, if you are interested you really should read it!
https://pub.tik.ee.ethz.ch/students/2021-FS/BA-2021-07.pdf
Basically, there are a ...
- 56
1
vote
Accepted
My ETH gets sweeped in milliseconds by a bot, what are the mechanics behind this?
Look up "Ethereum is a dark forest".
Before a transaction is mined, it is exchanged between nodes, who keep it into what is called the mempool. Anyone with a connected node can look at the ...
- 7,386
1
vote
Way to tackle arbitrage bots
Ok, here's what's happening:
I'm almost sure there exists another exchange with a lower price for the pair, otherwise the arbitrage opportunity wouldn't exist.
The pair creation tx was enough to ...
- 4,639
Only top scored, non community-wiki answers of a minimum length are eligible