All Questions

Github only shows options for GPU and CPU mining. I would like to point an ASIC at my geth node. Does anyone know how that's done? Other pools will accept connections such as: stratum+tcp://eth.pool....

I have a function with a parameter of bytes calldata that needs to be decoded to a struct, but the call reverts in assembly. I believe the issue has something to do with the nested array. I have ...

I was given this assignment to initialize an array with 2 items but when I initialized them i had an error that said "invalid implicit conversion from int const_1 to uint256[]memory req". ...

const config = require('../truffle-config.js'); const token_parameters = require('../token_parameters.json'); const ExampleToken = artifacts.require('ExampleToken'); module.exports = function(...

Im using opencv in ganache in this app to send an ethereum transaction In my app im getting the transaction that i send like that nonce = web3.eth.getTransactionCount(account_1) tx = { 'nonce': nonce,...

I'm struggling to understand how to properly poll events emitted from contracts. The provider I'm using is Infura. My code boils down to the following: filter = target_event.createFilter(fromBlock='...

I was wondering if it is possible to convert a string to a bytes32 or bytes in solidity like this, I want an input in string and require an equivalent bytes32 and bytes both. input string = "...

I have a smart contract deployed in which there is a variable A whose value is updated through a public function fun_update(). I want to get all the addresses which updated that variable A through the ...

On my POA network there are 5 nodes/miners but suddenly all nodes stopped mining and giving this in console "INFO [09-05|08:50:16.267] Looking for peers peercount=4 tried=4 static=0". We ...

In the description of the LES protocol Canonical Hash Trie (CHT) structures are used by LES for quick initial syncing and secure on-demand retrieval of canonical hash mappings, block headers and ...

I am using web3py to make a transaction. But I am getting validation error: {'message': 'VM Exception while processing transaction: revert Need operator approval for 3rd party transfers.', 'code': -...

I am trying to update Truffle on Ubuntu 18.04. I currently have version 5.1.33 of Truffle installed on my system. u/lc2530hz:~$ truffle version You can improve web3's peformance when running Node.js ...

In a transaction that eventually calls revert(), if prior to the revert we have SELFDESTRUCT some contracts and thus received a gas refund, does the gas refund also get reverted?

The below function was working fine until I added a string parameter and saved the string to a mapping. Now when I call it it fails with an 'out of stack' exception. Is there something I'm doing wrong ...

Rust. For a method send() of a smart contract I need to process both events when the transaction is sent (and generates txhash) and when it is confirmed. From https://docs.rs/ethcontract/0.7.2/...

I have thought of a RPS game using secrether.io: playerA hashes keccak256(move+11charsRandomData) as hash and sends it to RPS smart contract. RPS creates a transaction to Secrether Smart Contract - ...

I need to deploy a lot of typical contracts with identical functionality. Is there a way for extending the already deployed contract in solidity? I hope to make a single big contract with main ...

As you can see with the code below the last person to call claimAuction cleans up the AuctionProposal but has to pay 383729 gas instead of 73846 for that cleanup, a 519% increase! My question is ...

I requested a USDT withdrawal from Bilaxy exchange to my Binance USDT (ERC20) account. However, on etherscan, the transaction shows as "Dropped & Replaced". Do you guys think I shhould I ...

I'm really new to solidity and there is still alot I dont fully get. I have created this smart contract. I am getting an error while performing a test stating that the id to be set by the push cant be ...

I am trying to configure ngnix proxy behind geth. I have assinged a dns name to proxy. If I call xyz.com--it will internally redirect to IP:8000(in which JSON RPC is running) This part is working fine....

I have a paper wallet from an ETH atm from 2 years ago. I am trying to sweep the funds onto a digital wallet. I have used multiple ETH wallet apps on my phone but none of them were able to recognize ...

How do I get all the failed transactions in last 100 blocks using etherscan or some other service? Also the reason for failure and gas involved in the transaction Checked few similar questions that ...

Are there any state channel implementations being used today, or in development? (Not including payment channels) I'm interested in practical use cases rather than theoretical examples like playing ...

Instead of transferring my BPT token to my wallet, I accidentally sent it to the contract itself. I sent 99,546.988023218400325838 BPT to the address 0x471eb7dcf6647abaf838a5aad94940ce6932198c The ...

I discovered truffle has truffle-plugin-verify that help you verify your contracts on etherscan. I wonder if similar functionality can be done with brownie ?

Is the below mapping structure a legit way to create a restricted mapping, or is the latter best practice? mapping(address => SomeStruct)[5] private structs; and mapping(address => mapping(...

I'm trying to mint an NFT token in contract B by calling a method on contract A, but I want msg.sender (in contract B) to be the address that calls the function on A, not contract A's address. I ...

Is the block number increase going to be more frequent than it is now ? The reason I am asking is because some smart contracts I am developing depend on the block number increase, so if this changes, ...

It's 2020 September 3. Fees to send 20 USDC to someone is about $10-15 worth of gas fees. How can I minimize the gas fees when using metamask? And is it true that if I set the gas fee too low, I would ...

I'm following the old documentation about hooks and I'm getting a problem at sending transactions: every transaction is sent twice, why? The next is the current core: <form onSubmit={...

Contract A wants to call an external contract B/C/D/E/F but the variable name is different within each contract B/C/D/E/F, and contract A does not know the variable name for B/C/D/E/F at the start. ---...

I worked with web3js(JavaScript) and used web3.eth.Contract with 2 params (json, address) and successfully got contract object. Now I started to work with web3j(Java) and don`t understand how I have ...

Is it possible to listen to contract creations on web3? For example someone deploys a smart contract on the ethereum chain. Is there a method in web3 where I can listen to such an event?

I'm trying to set up my own Origin framework and was wondering if it made sense to reuse the existing RoleManagement contract on the volta network

i stripped down to the bare minimum to interact with a contract with metamask it works nice, i can call/transact nicely with only minimum of html/js but on mobile metamask or trustwallet it simply ...

I just noticed that my contract 0xa150Db9b1Fa65b44799d4dD949D922c0a33Ee606 has the warning on Etherscan (yellow exclamation). This is in the Contract section and the contract has been successfully ...

Etherscan supports proxy contracts associated with its implementation contracts https://medium.com/etherscan-blog/and-finally-proxy-contract-support-on-etherscan-693e3da0714b since 2018. However, ...

I'm currently trying to test run source code from GitHub based on a 2018 tutorial where solidity was using version 0.5.16. I'm currently using truffle v4.1.14. Appreciate any help. Thanks! In the ...

I'm currently trying to test run source code from GitHub based on a 2018 tutorial where solidity was using version 0.5.16. I'm currently using truffle v4.1.14. I understand that there was an update ...

Typically a miner decides which transactions go inside a block. But does this have to be so? Is the actual mining process just a process to find the right nonce regardless of block contents or does it ...

I want to use delegatecall to make my contracts upgradeable. Is it true that variable layout may break if I change the solc version and therefore I should use the same Solidity version for all future ...

I have been using yield Farming (YFValue) and I noticed when I accept the contract via MetaMask. I set faming 500 USDT but in the contract the input was: Function: approve(address _spender, uint256 ...

Node 1 is mining but Node 2 is not syncing Running admin.peers on Node 1 gives: Running admin.peers on Node 2 gives: Both Nodes are using same genesis block When starting console on Node 2 I used --...

I canceled a transaction by sending another 0 ETH transaction to myself customizing the nonce in Metamask. Now the canceled transaction shows as "dropped & replaced" in etherscan, but it'...

pragma solidity ^0.5.16; library EmailRegex { struct State { bool accepts; function (byte) internal pure returns (uint) func; } function state(uint id) internal pure returns (State ...

function transferFrom(address sender, address recipient, uint256 amount) public virtual override returns (bool) { _transfer(sender, recipient, amount); _approve(sender, _msgSender(), ...

I am trying to send eth when my geth node is not fully synced (it's very, very slow) { currentBlock: 10683052, highestBlock: 10780597, knownStates: 57935524, pulledStates: 57929853, ...

I want to sanity check my geth installation before unlocking my wallet. My geth version on Ubuntu is Geth Version: 1.9.18-stable Git Commit: f5382591874220287de253bfc08b10afd5244927 Architecture: ...

Here is a very simple code that i am using :- let web3 = new Web3(new Web3.providers.HttpProvider("https://ropsten.infura.io/v3/XXXXX")); var balance; web3.eth.getBalance("...