All Questions

I have some ETH and many custom tokens sitting in a Mist wallet that will take many days to synch. I assume I can use the 'transfer from' function to move these tokens from this wallet without having ...

I want to limit transaction pending time to 5 seconds, after that the transaction considered as failed; does --txpool.lifetime solve the problem ?

at the moment I am experimenting with the factory/child-logic in solidity. With my factory contract I am able to create child contracts in which an auction is executed. Now I want to return a variable ...

A CDZC coin basically fork of PIVX . I am trying to send coin via rpc calls. Successfuly created RawTxn, SignRawTxn but unable to SendRawTxn. `await rpc.listunspent().then(async r => { ...

As I understand ERC721 contracts, in particular Cryptokitties, a cryptokitty is not associated with a piece of ETH but rather is just some storage associated with the Cryptokitty smart contract. Is ...

Recent code: pragma solidity ^0.5.11; pragma experimental ABIEncoderV2; contract Master { address Pi_C_Owner; address payable public NewAuctionPayable; //Hilfsvariable um ...

I need the safest way for an user to send any amount of Ethereum to address(0). The amount is calculated by the contract, and there is no limit (assuming there is enough funds). All the code I could ...

A function recives bytes as input: function foo (bytes data) How do I parse that into individual byte32 chunks? function foo (bytes data) returns (bytes32[]) My goal is to understand how to handle ...

Good afternoon all. Been searching around for an answer to this question and can't seem to find the exact solution I need. I have an ETH account on my Parity node that I want to move to Ethereum ...

How to send ERC20 to 0x0000000000000000000000000000000000000000 I have tried to do this on myetherwallet and it will not send as a transaction, is there a special way to send here? Thanks

How can I permission a quorum network? Imagine I have 3 nodes in my network and I install another node in my friends house. How can I prevent my friend add more nodes to my quorum network? thanks

This is the error I get. internal/modules/cjs/loader.js:631 throw new ERR_INVALID_ARG_TYPE('id', 'string', id); ^ TypeError [ERR_INVALID_ARG_TYPE]: The "id" argument must be of ...

I am getting: "No etherbase set and no accounts found as default" when trying to sync my node using: geth --testnet --rpc --rpcapi db,eth,net,web3,personal --cache=1024 --rpcport 8545 --rpcaddr 127....

I am trying to use Web3j to query the balanceOf() function of a standard ERC20 token as shown in the code below: try { String encodedFunction = FunctionEncoder.encode(function); ...

What is the setting at Parity private server, if I want to sent signed transaction? const sender = '0x...'; const senderPrivateKey = '...'; const recipient = '0x..'; const ...

Python version : 3.5.2. web3 version : 4.9.2. Ubuntu : 16.04. Also tried previous version of web3: 4.0.0

I want to send my ERC-721 to my friend. Fast. Any suggestions?

I'm a new user trying out the Rinkeby testnet. I followed the procedure in this youtube video. But I can't get ether. This page says "Invalid User... boom!" I've contacted GitHub. They suspect that ...

I need to store the transaction details to my database. And here is my code: var rawTx = { nonce: nonce, gas: estimate_gas, to: contract_add, value: '0x0', ...

I am trying to get Sage to generate all graphs with 7. I typed in the following: g7=[g for g in graphs.nauty_geng('7') ] I’d like to save as g6 data typeI file. How to do ? I want to use the g6 ...

Last block with latest transaction was mined 4 hours ago. Of course, other explorers can see the latest ones but I need the Etherscan feature of accessing the details storage change of transactions. ...

In the Bitcoin network when a fork happens, the block transactions from the shortest chain are reinserted again into the mempool. In Ethereum instead we have Uncle blocks and Fork blocks. What ...

PS D:\nodejs\rff\metacoin> truffle --network ropsten migrate Using network 'ropsten'. Running migration: 1_initial_migration.js Deploying Migrations... Error encountered, bailing. Network state ...

I'm getting following error message when trying to unlock account on AWS Lambda: Error: Node error: {"code":-32601,"message":"The method personal_unlockAccount does not exist/is not available"} ...

I am trying to run eth-netstart in my machine. I run geth using this command line: geth --datadir innofactory1/ --syncmode 'full' --port 30312 --rpc --ws --wsorigins "*" --rpccorsdomain '"*"' --...

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 ...

I am constructing a very simple 2 nodes private Ethereum network to study the mining behaviour. The consensus algorithm is ethash. In order for the 2 nodes to discover each other, I also setup a ...

Is it generally better to define a contract instance once, then pass it through your components like... class Parent extends React.Component{ constructor(props){ super(props); ...

I have a contract on Ropsten, and when I do this is python, I get a result: result = contract.functions.getLastUpdateTime(0).call() So I know the abi is there, the address, etc. There's another ...

web3js can not touch smart contract. var id = dragoncore.getGenesNum(); has no error, but always return back 0, never changed. -----------------------------web3js code ----------------------------- ...

First I started the private network and connected with 2 node . After I opened another terminal and used the command to open the mist: open -a /Applications/Mist.app --args --rpc /usr/local/Cellar/...

I want to watch for fileViewed event and it throws TypeError: market.FileViewed is not a function in marketplace.FileViewed{ ^ My solidity contract: pragma solidity ^0.5.0; contract ...

What is the best way to approach unit testing of smart contracts which inherit other contracts, and use custom modifiers? Here's an example of a simple Whitelisting smart contract which implements ...

I build, compiled and deployed (to Testrpc) the token contract from the cryptocurrency tutorial. The token offers the transfer(addres _to, uint256 value) method, which I would like to call from ...

I'm using the EVM One back-end with ewasm/geth according to the following instructions. Geth seems to be starting up as usual with the following command: geth --vm.evm=./libevmone.dylib How can I ...

To link library in migrations I use: await deployer.deploy(MyTokenL) await deployer.link(MyTokenL, MyToken) We want to use migrations as infrastructure deployment and then have a deployment factory ...

I have started geth node (connect to ropsten testnet) on my local OSX system. Command: geth --testnet --fast --bootnodes "enode://...

I'm trying to estimate gas cost of a contract call, i need to send a string to a contract, but i need to see if i overtook the GAS limit. I'm trying like this: Transaction t = Transaction....

I'm currently struggling to interact with my smart contract, I don't if it comes from the way I call the function or the way I connect to my smart contract. Here is the code const contractAddress = '...

Sorry for the silly question. I have a div container "product-card" , I want to loop the number of my deployed smart contracts time. every time when I loop I want to clone this div container and ...

When we put a low nonce in transaction options we got "nonce too low", but when a put a big nonce (bigger then transaction count) we got anything why ?

Can I have a main smart contrast that has many subcontracts that can be executed once they are called by other people? And the subcontracts can update the status of the main one if some conditions are ...

I'm new with blockchain development. I'm working on an old project which use solidity 0.4.17 and truffle ^4.0.0-beta.2; These versions were in the package.json file of the project. When I installed ...

I understand what a function selector is and how it is computed: The first four bytes of the call data for a function call specifies the function to be called. It is the first (left, high-order ...

I have this code but it's static and I wanna change it dynamically. function addCandidates(){ if( own == 1 ){ candidate[0].candidate_ID[0] = 1; candidate[0].candidate_ID[1] = 2; ...

Can I think of a smart contract as being analogous to a Class in an object-oriented programming language (e.g., Java)? Each transaction that uses the contract essentially instantiates an object of ...

I want to change the message in connection request window using web3js. I have attached screenshot here. kindly check it.

How do I fix this? I've already tried truffle migrate --reset and/or deleting the .json files.

is it possible to know what is the reason of transaction error from "error" object (nonce, insufficient fund ..) is there status or something to test using it ? Geth error message is generic, I ...

I have looked alot for information about this and lastly i turn myself to here. I've written a smartcontract and deployed it to Ropsten . I am then using web3.js to interact with my smartcontract, i ...