Questions tagged [erc-20]
The ERC20 Token Standard is a set of 8 functions to be included (in an agreed upon language) in a smart token contract in order to enable interoperability across multiple interfaces and dapps. These functions relate to (1) how tokens can be transferred (2) how to access data about the token, and (3) how to format key events like transfers and approvals. ERC stands for Ethereum Request for Comments.
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Can I cut a fee using multicall on Uniswap V3?
I developed my own frontend for Uniswap V3, and I was asking myself if I could cut a small fee of the input token using multicall.
Basically, I would calculate what 2 percent of the input token would ...
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token transfer using one account vs. multiple
I'm trying to send tokens to multiple wallets as soon as possible.
A. function can be run by only one wallet under onlyOwner.
function batchTransfer(address[] memory receivers, uint256[] memory ...
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token.transferFrom() Will Not Work with ERC20 Token
I've made an ERC20 token (TaylorSwiftCoin, aka SWFT), and I'm attempting to make a very basic smart contract. I'm running this on the Dune TestNet, and I simply want this smart contract to take 100 of ...
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There is an address that is hacked, the bot is monitoring it and payments are received regularly!
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 ...
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Want to Access remote dai smart contract in another smart contract
I want to transfer Dai tokens from account1 to account2.
My account1 has 50 DAI tokens.
Kovan Dai contract address given by makerdao is: 0x4F96Fe3b7A6Cf9725f59d353F723c1bDb64CA6Aa.
What I am doing ...
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Function burnfrom error: gas required exceeds allowance or always failing transaction
I have created a contract using Remix.
When I run the function burnFrom(), it shows:
gas required exceeds allowance or always failing transaction.
What am I doing wrong?
function burnFrom(address ...
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How did this address steal my Ethereum ERC-20 Tokens?
A person on Twitter told me about this DApp that gives her 1% ROI each day and since I was new to crypto and her lies was really believable to me and I had really big FOMO. I first put 100 USDT into ...
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Accessing funds that are sent to the smart contract address
If someone creates a smart contract (and is owner of that contract), is it possible for that person to collect ETH and other tokens, that are sent to the address of smart contract?
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How can I invoke an approve() function call from the user and not the contract?
I am working on a basic staking platform for practice. I understand that the user of the platform has to call the approve() function and pass the contract into it in order for the contract to use the ...
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I deployed my token on testnet on bsc chain and deployed success but total supply not showing on bscscan testnet and my cap value showing on remix?
hi i deployed my token on testnet on bsc chain and deployed success but total supply not showing on bscscan testnet and my cap value showing on remix after deployed contract by checking with ...
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How is Uniswap's way of calling the balanceOf function of an ERC20 gas optimized?
What is the redundant extcodesize check and returndatasize check that is mentioned here?
/// @dev This function is gas optimized to avoid a redundant extcodesize check in addition to the ...
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Neither Token name nor supply shown in etherscan, instead shown "() N/A"
Recently, I've created an ERC20 token on Etherscan and verify the source code but my token information such as token name and total supply not showing up..Instead it shows balance: 0 N/a and supply ...
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Creating ERC20 or ERC721 in Optimistic Rollup
If there's a dapp running in optimistic rollup that lets users mint new ERC20 and ERC721 tokens. How can ETH main chain know about the new minted tokens?
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How to transfer the whole balance of ERC20 token?
At the moment I have this code:
//............
const contract = new ethers.Contract(smartContractAddress, ERC20_ABI, provider);
const signer = new ethers.Wallet(prKey, provider);
const txSigner = ...
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Tracking all ERC20 token transfers without using the event logs
I'm currently using the geth implementation. The problem is currently I am tracking erc20 token transfers using purely the erc20 contract event logs and filtering for Transfer event, then saving that ...
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Calling "balanceOf" in a contract from another contract that imports it. Expected 1 Got 0
I have an ERC20 contract that calls BalanceOf in a ERC721 contract;
In my ERC20 contract;
import "./NFT.sol";
contract ERC20 {
NFT public nft;
constructor (NFT ...
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transfer Erc-20 tokens from an adress without Eth and pay the gas from another adress or destination adress
as the title completely explains I want to transfer some erc-20 tokens from one account that has no eth in it to another how can I do so without need to deposit some eth to that account?
Is it ...
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How to create and send Flashbot bsc?
I'm trying to redeem some ERC tokens lost in a metamask, I found this code from Flashbots https://github.com/flashbots/searcher-sponsored-tx
turns out that my tokens are on the bsc network, I made ...
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In the Remix Web3 Provider IDE, how do you call a function in an ERC20 token contract from another contract without getting an estimateGas error?
I am building a very basic smart contract, 'CheckAllowance', on top of the 'FiatTokenV1' ERC20 token in the Remix Web3 Provider IDE. When I try to check an address's allowance in the 'FiatTokenV1' ...
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Can a non-ERC20 contract user delegatecall to an ERC20's functions?
If ContractA is a non-ERC20 and/or does not implement the same storages as the ERC20 it is referencing (let's say USDC's contract), will it be possible to use delegatecall so that msg.sender of ...
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How to prevent ERC20 token to be traded publically?
I am creating ERC20 tokens for real state products where investors can buy/sell tokens but we want to oversee buy/sell process. For example, when investor want to sell tokens to other persons, it ...
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Transfering ERC20 Token on behalf of another wallet with only signed messaged
Is it possible to transfer ERC20 tokens on behalf of another wallet, with only the signed message or signature of the of the wallet you are transferring tokens from?.
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Fractional NFT Marketplace - Error with buy function - 'ERC20: insufficient allowance
I'm trying to build fraction NFT Marketplace, It's now working when I try to create a new NFT and show it in the frontend.
I'm now facing an error in my buyNFT function and no matter what I try it ...
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Fraction NFT Marketplace (ERC20) - error in buyNFT - Not enough Ether sent to buy the shares
I'm trying to build fraction NFT Marketplace, It's now working when I try to create a new NFT and show it in the frontend.
I'm now facing an error in my buyNFT function and no matter what I try it ...
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bought a token that is unsellable, but I do not spot the code in the contrat that is responsible
I bought this token, had a good app for trading and a well written medium which didn't seem scammish at all.
the token even managed to pass on the normal basic tools for honeypot detection and ...
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Error in creating instance of deployed contract using truffle console
I deployed Token and Crowdsale contract in separate migration files. During Migration, there was no error. Migration logs are share:
Running migration: 2_deploy_token.js Deploying DappToken... ......
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Doubt related to interface
We know openzeppelin has an interface named IERC20.sol, my doubt is related to interface.
As this interface has functions like:
function transfer(address to, uint256 amount) external returns (bool);
...
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Why is my approve() function using incorrect token_id
I have created an ERC20 token using openzeppelin and web3. I am then trying add some of this new token to a contract (An instance of UniswapV2Router02.sol) in order to add liquidity to a liquidity ...
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Why am I getting an error that addr is not configured for ENS when trying to transfer an ERC20 token on Goerli testnet?
So I am getting this: Error: resolver or addr is not configured for ENS name (argument="name", value="", code=INVALID_ARGUMENT, version=contracts/5.7.0)
I know everything's well ...
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How can we lock an ERC20 token in a contract and generate another ERC20 token proportionally over the locked duration?
"Gnosis tokens (GNO) are the generator for Wisdom token (WIZ)
creation.
WIZ can only be created via activating the utility of the
Gnosis (GNO) tokens. This is done via a smart contract system. ...
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Fetch vesting schedule for a token in an account by using web3.py
Private investors usually have tokens locked in their wallet and released by a specific schedule. I want to find this schedule for any given token contract address and a given wallet address (function ...
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Cannot use transfer method of ERC20 in map function
I'm trying to iterate through receiver array to send ERC20 token in bulk.
I tried to debug with console.log and seems like the problem is line const tx = await contract.transfer(receiver[i], ammount)
...
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how to add my custom token to 0x protocol in testnet/mainnet
I am new to the 0x protocol. Is it possible to add custom token using 0x Portal DApp?. Share any example or document.
I have deployed my own exchange medium. it is running in http://localhost:3001
I ...
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Can't sign approve transaction in Uniswap
I created a simple Erc20 token contract, i'd like to make the token approval on exchange(uniswap) only avaliable for just the owner of the contract. Everything seem to work fine but when a user goes ...
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"revert erc20 transfer amount exceeds allowance" error with transferFrom() but not with _transfer()
I confirmed that approval is accurate, yet I receive the "revert erc20 transfer amount exceeds allowance" error when using the transferFrom() function. Yet for some reason the internal ...
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Minting/Sending 0 Value ERC-20 Tokens in Response to Transaction in Another Contract
I currently have a working ERC-20 contract for a small group that I am in. I would like to make a new contract that mints or sends a 0 value token without liquidity similar to a rewards token that has ...
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How can I import an existing ERC20 token into my contract?
I'm trying to develop a staking contract. All of the guides I've seen utilize either payable (ETH) or a newly created token. How can I import an existing token (presumably via address) into my ...
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Batch Transfer ERC20 Tokens From One Wallet To Another Wallet
Is it possible to batch transfer ERC20 tokens from one wallet to another with one transaction call?
For example, one wallet has 10 ERC20 tokens. We want to get all the ERC20 token contracts in wallet ...
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Transfer Ownership of a contract
Someone is making me a dex and a token, and i am not sure if TransferOwnership to my erc20 address it`s enough.
Token will be mintable with a mint rate/block of 4 tokens, and initial supply of 1 mil.
...
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I'm confused about decimals and total Supply with my erc20 token
I created erc20 token. I want total supply of 50,00,000.
And I want to give 7% tax on every transaction.
So if anyone sends single coin then, how can I get 7% and transfer remaining to receiver?
For ...
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Swapping ERC20 tokens on MyEtherWallet
I just found out about the token swapping function of MyEtherWallet: https://kb.myetherwallet.com/en/swap/swapping-via-kyber-bity-changelly/
Now, let's say I have a lot of ERC20 tokens that I want to ...
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Can't set up basic token contract
I'm trying to set up a simple token contract and deploy it but i'm having some trouble.
This is the token contract
pragma solidity ^0.8.0;
import "hardhat/console.sol";
contract Token {
...
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Move ERC20 tokens from Ethereum Wallet Contract to Account
In my Ethereum wallet, I am trying to access my wallet conract. If I sync in light mode and import the wallet contract address it just stays there displayed, greyed out and nothing happens, no matter ...
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not implement an abstract parent's methods completely or not invoke an inherited contract's constructor correctly
Having This error while deploying.
pragma solidity 0.4.25;
// ----------------------------------------------------------------------------
// Sample token contract
//
// Symbol : {{Token ...
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When I create a presale token how do the inputs? [closed]
I created a pre-sale token and I want to input the total supply, name, symbol and all that. How can I do that on locally?
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Send custom ERC20 tokens and deduct gas from master/another wallet
What I have currently -
Master wallet : Contains ETH balance
Deploys ERC20 contracts to mint custom tokens.
User wallets : NO ETH balance
owns tokens of the deployed contract.
Contract : Custom ...
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Create a MAX SUPPLY to Mint ERC20
I want to create an ERC20 on Solidity.
I want 1000 TOKENS of MAX SUPPLY (Like the 21m of bitcoin).
PERSON A: Mint to his wallet 700 Tokens. (Thats okey)
Only 300 Tokens are available.
PERSON B: Mint ...
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get decimals from contract
What is the correct way to get the number of decimals using web3? For example, how would I get the number 6 as a result when trying to obtain USDT decimals from the contract address?
I was using ...
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how to implement payment for smart contract functions not in eth but in any erc20 token
I want to write a Smart contract where for a call to a specific function, for example, erc20Pay, not ETH will be accepted, but a regular erc20 token with a specific contract address. how can this be ...
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Where can I find compiler info to verify & publish an ERC-20 token on Etherscan when I didn't write the code?
I'm a developer working for a small startup with a standard ERC-20 token that we'd like to verify on Etherscan, but I wasn't the person who minted the tokens initially (that developer no longer works ...
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