All Questions

I created a token in the Ropsten network. It wants abi.json when transferring with Web3. But the token I created did not give it. My token etherscan link https://ropsten.etherscan.io/address/...

Firstly, I have created a node in quorum private blockchain and initiated genesis to create blockchain using geth and bootnode . Then, I run the node and it is running blockchain. Later, I tried to ...

yesterday 2.3.2021 at 18:25 i was hacked. they stole all my founds from metamusk wallet from my address 0xeD14989682D3770AC0a9AEB2608Aa2315cF312Df and took everything to this address ...

I am confused by this simple contract. The main purpose is to bypass the OnlyContract() modifier. Victim contract. pragma solidity 0.7.6; contract Victim { modifier OnlyContract() { ...

I am learning to code in solidity and stuck with view functions. I am trying to return values taken dynamically in a structure using view function. Is there a way to do it is solidity? I tried it but ...

I have the following piece of code in my contract. It's supposed to take in a byte string composed of a uint flag that is followed by a variable list of uint numbers and contruct a call using those ...

I have found this mixer proposal https://hackmd.io/@HWeNw8hNRimMm2m2GH56Cw/rJj9hEJTN?type=view I'm is interested in this topic, but from my point of view with a current ethereum state it won't work. ...

Quick checking around there are exactly two references to an Ether Mixer - this non functioning and here (r/ethereum) 24 days ago. Unless I am missing something how can I hide the source of an ETH ...

I am developing a private ethereum-based DApp and writing an academic paper for a final year project. I'm trying to "blockchainify" an existing system that adopts a traditional client-server approach. ...

I clone pancakeswap-frontend. when run I got above error. But I can't solve this problem. Unhandled Rejection (Error): invalid address (argument="address", value=undefined, code=...

While I'm able to successfully swap ETH for DAI, I'm running into an INSUFFICIENT_OUTPUT_AMOUNT error when trying to swap DAI for ETH using swapExactTokensForETH, even with amountOutMin set to 0. I ...

I'm working a evidence application with quorum.I want to store the entire contents of a file on my private blockchain. Although it's not recommended. At first I use a linux command 'split' cut a big ...

I have a java server that uses web3j library with geth as the provider. When I tried to deploy my contract on my private test net. I got this error: org.web3j.protocol.exceptions.TransactionException: ...

I am trying to deploy contract (available at Etherscan.io ). I proceed following steps: copy its contract creation code and save them in crCode variable. Then i tried to to run following code; async ...

If an Ethereum wallet address was created using MetaMask, can the IP address of the wallet's owner be logged or uncovered somehow? If we can't find out the IP address, does the company running ...

I am going to get all ehtereum wallet addresses with positive balance. I tried to get addresses with a method to get transaction. I have got transaction from blocknumber(0~ Inf). Using web3 and ...

As a newbie I made a mistake whilst transferring btc to from Binance and Coinbase. My mistake was I didn't check the receive address with Coinbase and it defaults to eth and I wanted to send btc to ...

I am new to blockchain and working on a university project. I am trying to simply buy and sell music over the blockchain. Currently I am using a string to act as the 'transaction', but learnt this ...

I am trying to do a simple test for events. Following is solidity code. Values received from chgEvent.watch are always correct. But in chgEvent.get, results1 is empty. chgEvent.get does not get ...

So you deployed your brand new ERC20 token to Uniswap. I understand you need to provide liquidity for your token pair in Uniswap so people can start buying your token. Now, what I'm trying to wrap my ...

I'm putting together an ether/erc20 token wallet in a chrome extension but would like to follow best practices with regards to private key security. I'm using localstorage to handle login and its ...

Truffle is telling me that it costs 1 Eth to deploy. Is that seriously the cost of deploying a simple contract (this is my first Mainnet deploy)? Or is there something else going on? mainnet: { ...

I'm trying to understand the following code from the Solidity documentation: struct Funder { address addr; uint amount; } contract Crowdfunding { struct Campaign { address payable ...

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'...

Is it possible to use Uniswap V2 router on rinkeby? What is the contract address of a router? i found only factory contract address ?

I have a smart contract and it's native bindings generated in go-ethereum (version 1.9.11 if that matters) abigen. Im looking for a way to estimate gas limit before calling method on smart contract. I ...

I'm running a light node on a DigitalOcean VPS in order to use it to query data on the ethereum blockchain, but suddenly it stopped answering to any of my requests and i noticed that i always have 0 ...

I forgot to verify the ERC20 token contract after deploying it. Now after 5 months, Im doing it again and completely forget which compiler and if I accidently change anything on the code. After ...

Deploy the ethereum contract token and transfer token from one address to other address using node js web3.Anyone please help me.

I'm trying to create and deploy a smart contract through NodeJS using web3, but it is not working as I get a "web3.eth.contract.new is not a function". Here is my code: var web3 = require('ethereum....

I am trying to analyze if/how staking affects the price of an ERC-20. Is there a way to find the total number of a specific ERC20 token staked each day? Does the transaction hash or input provide any ...

Let's consider the following completely useless code (tested in Remix): // solium-disable linebreak-style pragma solidity ^0.8.0; contract MyContract { struct TestVars { uint8 a; ...

I've added EOS to MyEtherWallet as default token. How do I correct this? It tells me to load tokens but it isn't in the list. The contract is fine and tokens are present, just elusive and misnamed.

EDIT: I restarted truffle and migrated the contracts once again, and it worked without any errors. But, I don't know how and would love to understand this. Explanation - Owner creates an item, which ...

I have a geth node launch on linux, I want to access it through the IPC connection in a Node.js application. I am getting this error : /home/**/node_modules/web3-core-helpers/lib/errors.js:66 ...

I have a Windows installation that cannot be booted anymore. I'd like to copy the file containing the Metamask wallet seed to another machine and have that Metamask installation use it. The same ...

I have followed this answer. So, you just need to add the --rpcapi "eth,net,web3,debug" command line option. The way I run my geth: geth --datadir /home/user/POA/private --rpcaddr 127.0.0.1 --...

Lets consider a simple Contract that is to track a variable. A client App needs to access this variable's history to show a graph. I can create an Array inside the Contract, and push() the value ...

Why does the require not throw here when I am passing an empty string for the _name param? function MyContract(bytes32 _name) public { require(_name.length > 0); name = _name; }...

I make a web application, that needs the events from my contract to initialize it's state. I was using infura websocket provider, but it seems to lag a lot and close the connections unexpectedly ...

I wonder how can I natively pop-up the MetaMask window to send specific amount of ether as a donation to already defined SC address and ABI? Short code intro: pragma solidity >=0.7.0 <0.8.6; [......

I am able to publish my contract in testrpc , but when i am trying to publish same contract in geth, i am getting below error: creation of lease errored: Gas required exceeds limit: 3000000. An ...

I'm quite stuck with this issue. It seems like it must work, but it doesn't :D Have a contract on rinkeby network which is working perfectly through remix(load by address) and truffle console. ...

Solidity file pragma solidity ^0.5.0; contract Todo { struct User { uint id; string name; } User[] public users; uint public nextId = 1; function create(string memory name) public ...

I am developing an application using solidity, web3js and eventeum. I am testing it locally using ganache-cli. I use Kafka to store all the events to process them at convenience instead of processing ...

When I deploy contract test net, it shows an error that gas limit exceeds: 3000000 What's the solution? Github Link to the smart contract. And is it normal to have the infinite gas estimate of ...

Let's say you've tokenized your house as a non-fungible token (NFT) on the Ethereum blockchain. if an NFT simply represents ownership of a tokenized asset, what actors or agencies currently will ...

I'm trying to implement my own version of a SmartContract-driven Discover protocol and in order to get it fully working, I want to remove the admin.addPeer() command from the console. I know there's ...

1) First, I got the input console.log(web3.eth.getTransaction('0x725fc75264726f409793164e336e7d5ed35df8d2be469a0cc1a3a8cc4756b9b9').then((i) => console.log(i) )); 2) I manually pasted the input ...

The on-chain aggregation smart contract for ETH/USD on the mainnet (https://data.chain.link/eth-usd) is at this address https://etherscan.io/address/0x5f4eC3Df9cbd43714FE2740f5E3616155c5b8419#code. If ...