Category "solidity"

sign and verify message with solidity and python

I am trying to perform a certain action say like selling a token only when the message sent to a contract is signed by the contract owner. I knew how I would do

Can smart contracts deploy other smart contracts?

If a smart contract has the compiled bytecode for a contract can the first deploy a subsequent contract? According to Ethereum.org: "To deploy a smart contract,

Error: VM Exception while processing transaction: reverted with reason string 'ERC721: transfer caller is not owner nor approved'

i try to write NFT marketplace and i have problem with reselling items from user that buy item from owner and new, third user. I use next.js + openzeppelin + ha

Member "name" not found or not visible after argument-dependent lookup in struct xxx storage ref[] storage ref

Solifity 0.8.0 with struct struct Placeholder{ string a; uint256 b; } mapping(uint256 => Placeholder[]) public placeholder; why this error Member "b" no

ImportError: No module named solcx

I installed py-solc-x via pip3 install py-solc-x in the terminal but when I run the program, I still get an importerror. What's going on here? My code: from sol

ParserError while compiling solidity code

I am new to solidity. This is my 1st simple project when I do node compile.js & I am getting following error: My Error : { contracts: {}, errors: [ ":

Unhandled Rejection (Error): call revert exception

I am getting this error message when trying to interact with my smart contract on my react front end. I am running localhost3000 and which requires metamask to

Visual Code Studio, File Import Callback not Supported - File Source not Found

While trying to troubleshoot another issue with my project, I must've broken something along the way, but I have no idea how to fix this. These are my import st

How to store each NFT image in a ERC721 contract? [closed]

When creating a ERC721 contract that manages thousands of image NFTs, saving these image byte pixels in arrays on the contract doesn't seem ve

How to store each NFT image in a ERC721 contract? [closed]

When creating a ERC721 contract that manages thousands of image NFTs, saving these image byte pixels in arrays on the contract doesn't seem ve

Trying to run a Brownie Dapp in Docker

I'm trying to run my brownie dapp in a docker container, but i always have the same error and can't seem to fix it: FileNotFoundError: [Errno 2] No such file or

How do I set Royalty on OpenSea from my DApp?

The project we are supposed to make is a minting page that can set royalty fee on opensea testnet from the dapp itself (i.e. you cannot set it from open sea's i

totalsupply() is not a function openzeppelin contracts

I'm trying to import some contract files from open zeppelin so my solidity smart contracts can inherit their functionality, when trying to write chai tests that

eth-brownie - No module named <Users.someuser>

Getting this error while trying to run a eth-brownie script on MacOS ModuleNotFoundError: No module named 'Users.xyz' Run command: brownie run scripts/mainne

Getting error while deploying smart contract using truffle

2_deploy_contracts.js ===================== Replacing 'SimpleStorage' ------------------------- Error [ERR_UNHANDLED_ERROR]: Unhandled error. ({ code:

ParserError: Expected identifier but got 'payable'

This is the code thats giving the error, the line is set to bold. //SPDX-License-Identifier: UNLICENSED pragma solidity ^0.8.13; contract CrowdFunding{ mapp

Source "@openzeppelin/contracts/token/ERC721/ERC721.sol" not found: File import callback not supported

I've imported the Open Zeppelin ERC721 token standard into my VS Code with the Solidity extension, but see the following warnings on all my OZ import statements

Decode constructor arguments in solidity

I playing Ethernaut Level 8. The goal is to get access to the private password state variable and unlock the contract. I know one could use await contract.unloc

Compilation failed Internal Compiler Error: Stack too deep, try using fewer variables

I am trying to compile the bellow contract and i am getting the error. If i remove the mapping i dont get an error: Compiling using default compiler, solidity v

Sender account not recognized on private ethereum network

I'm currently developing a dApp in Solidity and am working on a web3 library to handle communication with it. I struggle with the process of new account creati