Category "ethereum"

Can't verify ERC20/BEP20 token on BSCScan

I deployed an ERC20/BEP20 token on binance smart chain using truffle and openzepplin. Now I want to verify this smart contract but I have some issues. $ truffle

Web3py merkle tree support

I am trying to implement a merkle tree just like merkletreejs but python does not have any good libraries that support keccak256 and sorted keccak256 trees. Doe

Integrate Login and Signup with Meta mask in ASP.NET MVC?

I want to Integrate Login and Signup with Meta mask in ASP.NET MVC. looking for it for so long. Checked Metamask tutorial but it has code in node.js and the lib

Rinkeby Authenticated Faucet is offline

I wonder if anyone has successfully requested ether on https://faucet.rinkeby.io/? I followed the instruction and it kept saying Faucet offline. Any workaround

How to get all transaction from an address via the etherscan API in R?

I've been looking for a way to download all transaction from a specific contract since their start up until now. It's around 25k transactions as of today. I've

Can I extract BSC transaction details programmatically without going through BscScan?

I would like to get the data that's displayed on BscScan programmatically, but their API seems quite limited, and I would like to avoid parsing HTML content to

How to set price for all NFTs in a collection on opensea?

If I mint a collection of n items on my own address (via smart contract) , it'll be publicly visible on my account under the collected / created section like th

What is the 16 in (chainId, 16) in an Eth smart contract that is on the Rinkeby network

I am new to smart contracts and I am working on an Eth Rinkeby dapp and was wondering if anyone can tell me what the "16" means in this section: } network =

Restrict function access ONLY to one other specific contract in Solidity

I have a security problem in my Solidity contracts and I can't figure out how to fix it. The flow goes like this: First, we create an instance of contract A; Cr

uniswap V2 invalid BigNumber value for JSBI negative value

Hi I was following uniswapV2 document to perform a trade transaction and I encounter error as follow invalid bignumber value I got my input amount as 2941991120

Embark_demo/embark run is not starting

I followed the instructions and install all the prerequisites that was listed as required to setup Embark; however, when I reached the dmo test piece, I am not

Find Floor Of Opensea NFT

Is there a way to get the floor price thats displayed on the main page of an NFT collection? Here you see the floor price is 5.75 but if I query the contract u

How to send ETH to a contract function with ethers.js?

I am trying to send ETH to a contract function from a web app via metamask and ethers.js. So far I have tried: const provider = new ethers.providers.Web3Provide

Ethers.js "Error: unknown account #0 (operation="getAddress", code=UNSUPPORTED_OPERATION)"

I'm trying to fetch the price of ETH from KyberSwap, using Ethers.js, but I'm receiving the following error: Error: unknown account #0 (operation="getAddress",

Getting Promise Object when Calling Solidity Functions

I have a function in my smart contract where I am trying to return some data that has been stored in the blockchain, function showOrg(address org) external

Solidity mapping not returns an array in a struct

The Solidity's mapping not returns an array inside a struct (when call mapping_data(), the data variable is undefined). Just be able to read it from read() func

Implementing fixtures with @nomiclabs/hardhat-waffle

In the official waffle documentation you may find the next way to implement fixtures: import {expect} from 'chai'; import {loadFixture, deployContract} from 'et

Invalid signature error from ethers when trying to verify a signature

I am working on a dapp that needs to verify users' signatures. When testing with Metamask, everything is okay. When trying to verify a signature from Ambire wal

`Property 'ethereum' does not exist on type 'Window & typeof globalThis'` error in React

I am getting the Property 'ethereum' does not exist on type 'Window & typeof globalThis' error in React. This is the line generating the issue: import { eth

Error: TypeError [ERR_INVALID_REPL_INPUT]: Listeners for `uncaughtException` cannot be used in the REPL at Object.compile

I am new to truffle and I work on blockchain project so when I "migrate" in truffle develop, this error occurs. Why ? I change the version of my compiler by 4.2