All Questions

I decided to deploy my NFT collectibles in BSC (Binance Smart Chain) because of Gas Prices in Ethereum blockchain. So, I researched some Dapps deployed in BSC. I've found that most of the applications ...

I would like to get an oracle for values of countries' based currencies. Are there such free oracles?

How can someone withdraw the incoming money so quickly? 0x7E5F4552091A69125d5DfCb7b8C2659029395Bdf in - https://etherscan.io/tx/0xfbd225c6a5e7dc1ba76978d32914a6c18928a448540f2f235bca83e119c5f8a8 out - ...

I have successfully created the multinode network, but some when trying to deploy smart contracts, some of them fail. This is the config of my genesis: "config": { "chainId": 999, &...

I would like to write a contract, that fetches a data from oracle in a specific point of time (or later) Is there any option to pop up an event in some point in the future in Ethereum contract? The ...

I have a smart contract that deposits user's fund in the AAVE lending pool on behalf of users: lendingPool.deposit(stableCoinAddress, amount, address(this), 0) Users can deposit at different times ...

I am really new to smart contract development,b but I have been watching some videos, I want to create a smart contract where players can choose how much Ethereum they want to put in ( within a range ...

Remix debugger seems to be pretty mature. But, its web-based interface makes it impossible to shuffle the block around. For example, I want to move the "Stack" section to the right sidebar ...

Take the following code: contract Foo { function increment(uint256 x) external returns (uint256 result) { result = x + 1; } function increment_twice(uint256 x) external ...

I have a basic node express application. It connects to my locally running hardhat network via ethers & websocket. The connection seems to work, since I can query the blockchain succesfully (for ...

Im trying to deploy the contract AmazingBEP20, i use: http://remix.ethereum.org/#optimize=true&runs=200&evmVersion=null&version=soljson-v0.8.3+commit.8d00100c.js Contract i want to deploy ...

I am using the web3-implementation from python (web3.py) and use the both methods get_transaction and get_transaction_receipt to lookup failed transactions. If the status-field from ...

I have two smart contracts. A caller and a receiver. My caller code looks like so: // SPDX-License-Identifier: G.P.L 3.0 pragma solidity 0.8.3; contract Caller { event Response(bool success, ...

I am testing a multinode Ethereum private network setup with Docker, 1 bootnode, 1 node, 2 miners, netstats and 2 swarm, total 7 containers. When I stop and restart the containers, the chain stops ...

I'm trying to get Transaction Action information from Etherscan Apis by using a transaction hash without success. Here is what I want to extract (Swap 1 Ether For 2 Yf-DAI) with the API. I have ...

I'm trying to understand some of the finer points of NFTs. What makes NFTs traceable? Is it the transaction history stored on the ledger? Is there anything else to it? Key to the NFT's traceability is ...

I have a contract which has an event. The contract's code is pretty simple: pragma solidity >=0.7.4; import "./Crowdfunding.sol"; contract Factory { address[] public ...

Is it possible to have decimals balances in ERC721 ? I mean is it possible to say i own 50% of an NFT for example ? Thanks

the title says it all txn hash 0x4b17096471284533342a55ece11c62fb449e5d75f9e8b80f4cebda70d36807f2 scenario: i accidentally sent kimchi finance token from my metamask wallet to my ethereum address in ...

I'm looking to generate a random ethers.js BigNumber in a certain range. While this question has answers about random number generation, the answers as of this writing (April 2021) only cover BigInt, ...

Here is my A contract: // SPDX-License-Identifier: MIT pragma solidity >=0.4.22 <0.9.0; contract A { B public b; constructor() public { b = new B(); } } contract B {} As ...

I have transferred some ERC777 tokens to an ERC20 Ethereum account on my Ledger wallet. The transaction was successful and confirmed by etherscan. However, I cannot find the tokens in my Ledger ...

This is the normal Data that I saw: amount0In : 4000000000000000000 amount1In : 0 amount0Out : 0 amount1Out : 55176985192271150 But this one is different: amount0In : 55242685893542 amount1In : ...

For some reason, our app will only work with a forked instance of the mainnet. And hence, we want to run our test on the forked ganache. We are using truffle, so we have written all of our tests in ...

Let us say I am a miner. Can I accept my transactions into the blockchain at no fee to myself? And what do I lose? Let us assume someone is running a dapp. Can they mine transactions of that dapp to ...

I have a question about writing functions in Solidity - I am trying to create an array of dog structs but I can't seem to get the function declaration correctly: pragma solidity ^0.5.1; contract ...

Background: I'm writing a contract that inherits ChainlinkClient in order to make an API request via an oracle job: function fetch() private returns (bytes32 requestId) { Chainlink.Request memory ...

I have two contracts, main and config. On main contract there is this buy function: function buyItem(uint256 itemId, uint256 amount) external payable { uint256 ethPrice; require(msg.value &...

I bought ETC via website https://classicetherwallet.com/ by generating the wallet in 2017. After that as the market went down. I was diverted and never looked into. However recently i came to know ...

How do I return token amount in USD using web3js ..or is there some kindof API to be used ? For instance , say user has 3ETH and also want the user balance to show in USD just as metamask does

I have a couple of questions related to transferring ERC20 token to a contract. I am developing a protocol that has its own token to provide incentive mechanisms. For certain operations I need to lock ...

Which one is better to check short period of time change 60seconds block.timestamp or block.number?

Error i'm getting back when I run truffle compile ParserError: Expected ';' but got 'contract' How my contract looks: pragma solidity ^0.6.0; import "@openzeppelin/contracts/token/ERC721/...

I'm trying to follow the simple "Getting Started with Geth" page instructions but it is not written very well and I'm doing something wrong. This is the page I'm looking at:Getting Started ...

When querying the following with the thegraph playground (compound v2) { account(id: "address here") { id totalBorrowValueInEth } } returns { "data": { "...

I am trying to access a simple variable on my smart contract, locally inside my nodejs application. The relevant parts of my contract look like this import "@openzeppelin/contracts/utils/Counters....

I have some eth wallet addresses, and I want to monitor the transfer information of these wallet addresses on some smart contracts.I use this function: query := ethereum.FilterQuery{ ...

I'm trying to use Uniswapv2Router with Truffle and Ganache, but haven't been able to identify what I'm doing wrong. I'm using addLiquidty method as follows: await uniswapV2Router02.addLiquidity(token0....

I have a smart contract that accepts user funds and adds them to an AAVE lending pool (DAI for example). Something like this: lendingPool.deposit(stableCoinAddress, amount, address(this), 0); As you ...

So, the bot instantly cancels these payments by sending, for example, 0.01 eth with a commission (fee) of 0.009 to another wallet, or even canceling everything through self - sending 0 to the same ...

Im developing locally but I need a full copy, Im using ganache for local dev, also providing -f option to fork another blockchain (BSC), is it possible to download the complete chain somehow?

this is their contract: https://bscscan.com/address/0x95d25105237ced24523bbc3880b2551248e90de2#code I cannot find the minting function in the contract, also how would they be able to call it? cheers!

I have a Smart Contract that I'd like to build a web based marketplace app for. How can I list all available "Items" in the contract. Seeing as there is no upper limit to the number of ...

I am reading the SEC prospectus Coinbase's initial public offering, available here. On page 20, it is written: Many crypto assets have concentrated ownership or an “admin key”, allowing a small group ...

I am building a blockchain game where users can update their character's appearance. This is done by calling a function called updateAppearance in smart contract. I want to show latest version of that ...

The docs on Solidity v0.8.0 Breaking Changes mention that overflows are now checked by default: Arithmetic operations revert on underflow and overflow. You can use unchecked { ... } to use the ...

This is my send code: window.videoContract.methods .mint(account, 'https://ipfs.io/ipfs/QmRQC1...') .send({ from: account, gas: 20100000 }); If I set it too high, I get ...

I do not understand something: ERC721 standard interface contains a name and a symbol. ERC1155 is very similar to ERC721 and I do not understand why there are no symbol and name variables in ERC1155. ...

I'm using Truffle and Ganache for my development environment. Using the truffle console or truffle external scripts everything works fine, but truffle test does not seem to be connected to Ganache: ...

I am getting the following error when trying to mint through my ERC721 contract. How can I determine the cause of the failure? https://explorer-mumbai.maticvigil.com/tx/...