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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Spot the problem in the contract of the unsellable token
I am currently trying to understand how the smart contracts work. I have bought a tiny amount of a token that I suspect to be honeypot and indeed it is unsellable, PancakeSwap gives the error: ...
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Error occurs when my gas fee isn't zero. Otherwise transaction runs fine with 0 gas fee
I've created a smart contract that helps user to buy erc-20 tokens in exchange of matics.
I am getting this error whenever I do some calculations in my function, which increases gas fee.
I have 0....
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How to make this Swap Function only work when requirement is fullfilled
Hi I'm new in contract developing. The following snippet includes a swap funtion for a swap on uniswap. This swap should only work if the requirement require((balanceOf(to) + amountToSwap) <= ...
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Swap, usdt to usdc, eth to usdt, eth to usdc etc
Can someone explain how to swap, usdt to usdc, eth to usdt, eth to usdc etc. Without any third-party (uniswap, 1inch etc). In language java/kotlin. For mobile wallet an application
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Smart contract holds USDT
My smart contract holds some USDT token and now if someone knows my Contract address can he/she transfer that USDT to his/her address.
Just to clarify the USDT contract has transferfrom function which ...
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Strange Token Sale on Uniswap - Need Help Understanding
I found a weird issue with a new token on Uniswap. The total supply is 690 billion, and 660 billion went into a Uniswap pool. The creator gave up control.
Now, here's the odd part: someone sold over ...
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Adding Uniswap interface to a ERC20 token smart contract
I just started learning Solidity, as browse through various smart contracts for tokens listen on Uniswap, I notice that most of them use IUniswapV2Factory and IUniswapV2Router02 and a small amount don'...
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ERC20 Multisend works on Sepolia Testnet but Fails on Mainnet
I've got a smart contract function that takes an erc20 contract address, an array of addresses and an array of amounts and then sends the each amount to each address of the specified token. I've got ...
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Smart contract question [closed]
Can you see some scam in this contract?Try to figure out what's gonna here..
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.9;
abstract contract Context {
function _msgSender() internal ...
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Bought a scam token, trying to understand what part of the code should I check next time to prevent that
Contract code - https://etherscan.io/token/0x67bcd18a484a88f073097a18b0462eb7c44d3178#code
Ownership renounce at 08:17 UTC https://etherscan.io/tx/...
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Get a list of all erc20-token contract addresses [duplicate]
I would like to get a list of all ERC20 token contract addresses via an API rather than scraping the web.
Are there any web services or alternative methods available to do this?
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Return the current ERC20 token holders and number of tokens held
Are there any free APIs available that can provide current data on ERC20 token holders and the number of tokens they hold ?
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Multiple Solidity Versions in flattened file
I have deployed a contract to Mumbai Polygon testnet. While verifying and publishing source code, the flattened file has multiple solidity versions. I got the error below.
The OpenZeppelin contracts ...
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ApproveUSDT function not working internally, how do I fix this?
I’m experimenting with a presale contract based on the BSC testnet, and in the contract I’m attempting to achieve the purchase of my token with USDT.
Using my own code within the contract itself, I ...
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How to find the data sent to create a new Smart Contract
I am currently learning Solidity & Blockchain development. Came across an instance, where a new ERC20 Token contract was created from a front end App. While checking the Contract, I found a bunch ...
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Is sending USDT to Ethereum main network address Possible?
I copied my Metamask Ethereum main network Ethereum wallet address to someone who said "Supported Wallets: ERC-20 Compatible. E.g. Metamask," for payment. I want to know if the transaction ...
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Incorrect Decimals & Max Total Supply ERC20 Token
After deploying token contract on ethereum I am getting 0 decimals being shown on etherscan whilst other explorers displaying correctly.
I presume because of this Max Total Supply displays as:-
3,200,...
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Token with whitelist function, that would only whitelisted addresses to trade the token while trading is disabled
I want to create a token and add liquidity but only whitelisted addresses would able to trade the token while trading is disabled. If trading is enabled that means everyone can trade it but if it is ...
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Old ERC-20 TRX Tokens Swap Issue
I tried the instructions given here to swap my old (pre-2018 swap) TRX tokens based on the Ethereum network to the MainNet ones. I sent the tokens to the smart contract address mentioned in the ...
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Approve function called by an address in a smartcontract different from the token contract
I would like to know if an address can give approval to spend his tokens to another address or contract by calling the function approve in the same contract (not the token contract but another).
Thank ...
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Problem with "Openzeppelin ERC20Votes delegate function"
I hope you're doing great. I have been tinkering with ERC20Votes and creating a DAO for my Vendor contract. The issue I'm facing is that whenever I try to delegate my GovernanceToken contract to the ...
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How does etherscan checks that the contract is ERC20, ERC721, ERC1155 standard implementation?
Suppose I created any ERC20 contract, how does etherscan recognise that the deployed contract is an ERC20?
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ERC20 Network Fee
I have tried to withdraw 544K from my coinbase wallet, using ERc20, counbade is telling me that my withdraw amount caused the ERC20 Network to get congested, and it also triggered a fee of 20% fee on ...
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Implementing Gasless Meta-Transactions for ERC20 Token's Approve Function: Is it Possible with Deployed Contracts like USDC or USDT?
I am currently exploring the implementation of gasless transactions, specifically focusing on meta-transactions, to enhance user experience by subsidizing the gas fees. For this functionality to work ...
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How is it possible to broadcast an ERC20 transfer without actually having any?
There's this transaction https://etherscan.io/tx/0xd6cf7c502afe82491228c5f00929a94fe492c24973c150e7b2593a1e2274f75f
It never got executed on the node and was eventually replaced by a self transaction. ...
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Calling approve function of an erc-20 contract not working
I'm dealing with a problem, I hope someone can help me.
token: 0x9216e1BbC58Ba2bD90c5b49524659209ccaB32Da
contract: 0x8ca112e2fdFF220217609D391eec0B95d5E505a2
alumne: ...
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Minimal proxy contract, can make pair but can’t add liquidity
I have a cloneFactory which produces ERC20 compliant clones based on a master template.
I’m able to deploy my clones and even create pairs for the clones. But when I want to add liquidity (...
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Help needed: ERC20 token "BIGTIME" sent to ERC20 smart contract that accepts USDC, BTC, ETH, MANA
Recently there was a launch of a token called "BIGTIME" (ERC20) from Bigtime Studios (web3 game) listed on a DEX, which I bought tokens from and transferred to the games smart contract to be ...
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What was the purpose of adding the safeTransferFrom method? What are the cases when the plain transferFrom fails silently?
I was wondering what is the case when the plain transferFrom ERC20 method fails silently, i.e., just returning false.
Looking at the code, to me it looks like when the balance is insufficient or the ...
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How to Deploy any ERC-20 Smart Contract using Safe-Core SDK from Safe Address(gas less)
How to Deploy any ERC-20 Smart Contract using Safe-Core SDK from Safe
Address(gas less)
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Issue creating pair on IUniswapV2Factory (sepolia)
I have the following interfaces in my contract file:
interface IUniswapV2Factory {
function createPair(address tokenA, address tokenB) external returns (address pair);
}
interface ...
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Approval question
Beginner question:
I have trusted wallet with 1000 LINK erc20.
I want to swap it to get USDT erc 20.
It ask to approve the LINK.
How long approval takes?
In some time after I got the USDT, I wish to ...
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ERC20 total supply distribution
For an ERC20 token, what is a typical total supply distribution?
I'm about a month into solidity, coming from a .net full stack background. I have got a contract developed including adding liquidity ...
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How to get the ERc20 token price
how to get the erc20 token price like in chain link from this code i am getting the token price of price feed address but How to get my own erc20 token price from chainlink
// SPDX-License-Identifier: ...
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Robust way to index historic total supply for all ERC20 tokens
Is there a robust way to index historic total supply for all ERC20 tokens?
For tokens that update total supply through mint and burn (with proper events), this is easily done by tallying up mints and ...
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ERC20 token transfer failed When getting called by a smart contract
I'm developing a smart contract in Remix, and it is compiling correctly, but every time I try to execute functions related to the transfer function from my token ERC-20, it returns me an error saying ...
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Deploying contracts at same address
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;
/*
Let's say Alice can see the code of Foo and Bar but not Mal.
It is obvious to Alice that Foo.callBar() executes the code inside Bar.log().
...
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How to Download dependencies when auditing a hardhat project?
I just attempted to audit smart contracts that were tested using the Hardhat framework. In Foundry, after cloning the repository, I know that I can install all the necessary dependencies by simply ...
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How to get the token Price Of ERC20 token in same contract
How to get the token Market price value in the solidity smart contract. I want to fetch the token price in the same contract like there is A token and I want the token Market price value in the same ...
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ERC20 token smart contract check
I updated my smart contract code according to the explanations you gave and the instructions you gave. Please, if possible, check the rewritten code again and give your general opinion, is this smart ...
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I am not getting the starknet plugin from the plugin section
I am completely new and I want to deploy a contract on the eth network with my argent wallet. But I am surprisingly not getting ant starkenet plugin in the plugin menu. And no not even if I use other ...
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How should I integrate my ERC-20 Smart Contract into the existing cryptocurrency ecosystem?
I've created my own cryptocurrency based on the ERC-20 Smart Contract on the Ethereum blockchain. I want my currency to have the same functionality as Tether USDT, for example. To be more specific:
I'...
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How to get a token bluecheck from polygonscan?
I would like to ask about blue checks in polygon scans.
Is there any documentation that we need to submit to receive a blue check for our token registered with polygonscan?
On the polygonscan ...
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I bought a scam token. Cannot sell ! But the sandwich bot can buy and sell. How is that? [duplicate]
I bought a scam token. Cannot sell ! But the sandwich bot can buy and sell. How is that?
Contract address is 0x1ebb7e40c24eb100b68d1289ec2ac130f66eb77d
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How to give allowance to a contract and send erc20 between accounts
I wrote the following contract:
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
contract enviaToken {
address public ...
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I want use own ERC20 token to buy things
I create my own erc20 token and transfer into the metamask. Now I want to use for purchase things which i am listing on the website .For example ,i made a shop where different things are avaliable . ...
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Getting error ERC20: insufficient allowance even after the user approving the tokens. Need help with debugging
The following code is from a Stablecoin project.
To gain more context, please refer to this Github repo.
I've added a new function to the DSCEngine.sol name collapseDsc() which is responsible for ...
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How does Account Abstraction Paymaster compare the value of ERC20 and Ether?
To the best of my knowledge, the off-chain value is utilized by Chainlink and the on-chain value is utilized by uniswap's oracle.
However, I don't see anything related to Chainlink or Uniswap in the ...
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How can this account address selled more erc20 token then it received?
I'm using the Alchemy API to retrieve all transactions for a specific address. When I run the API for this address on this particular token, I only receive two transactions. The first transaction ...
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Can approve function be malicious?
I'm so confused on how approve functions works:
If myToken contract has an approve function but the owner did not approve the contract B. Then contract B deploys a function and create a function that ...
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