I have a Python script using Brownie that occasionally triggers a swap on Uniswap by sending a transaction to Optimism Network. It worked well for a few days (d
I am new to block chain. Suddenly I got a question did we can able to access the previous block data from the Ethereum block chain by block number. For example
I try to install truffle on windows with npm install -g truffle as administrator. I updated node.js npm and don't know what to do next. PS C:\Windows\system32&g
I have tried to make a ERC20 token that takes a transaction fee on every transaction (buy/sell/transfer) and this transaction fee gets distributed amongst the h
I need to send ether from externally owned account to contract. All code I found so far looks like this contract Contract { mapping (address => uint) ba
I want to get the value that is inside of struct in Solidity, but I have no idea how to get it. pragma solidity >=0.4.21 <0.6.0; contract PlaceList {
I'm learning blockchain development recently and I'm implementing ERC721 contract to mint NFT and store the mapping of ownership. What if I deploy a second cont
I am learning solidity and got to know that interface and abstract are both classes that may contain unused functions. My doubt is: What is the difference betwe
In the process of developing the ethereum dapp, I tested the load and there was a nonce error. When building a rawTx, I used web3.getTransactionCount("accountAd
I want to compile my ethereum HelloWorld.sol smart contract. In all the tutorials is that you do it like this: var solc = require('solc'); var compiledContract
When I run npx hardhat console --network rinkeby accounts = await ethers.provider.listAccounts(); I get Uncaught ProviderError: Must be authenticated! with bel
I'm using nethereum & unity with infura. (I'm developing an DApp.) I wrote some code for minting new NFT, and tested, and it worked very well. However, afte
I am developing an application on Ethereum blockchain. I use Solidity for contract and Nethereum c# library to connect to the contract. I am somehow new in Ethe
I am writing a script for a smart contract that I'll deploy using hardhat. I'm confused on the difference between .deploy() and .deployed(), what does each one
I'm trying to complete the simple collectible NFT tutorial from this freeCodeCamp video. (I'm getting stuck on the script that starts exactly where the link is
I am working on a project where I need to send ether from an user to a smart contract and from the smart contract to the user. The smart contract is code in Sol
An address in Solidity can be an account or a contract (or other things, such as a transaction). When I have a variable x, holding an address, how can I test if
I'm building a minting site that requires me to check the number of NFTs minted and display that number in real time to the user. At first I was just making a r
I am familiarizing myself with smart contract development using the brownie framework and solidity. To start of I was using the brownie console to deploy some s
Basically, I'm trying to make the smart contract be able to take exactly 0.05 eth ONLY when the cooldown timer is set to 0. The Dapp I'm creating is a first com