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.

Filter by
Sorted by
Tagged with
0
votes
0answers
9 views

What is the difference between SafeERC20.sol VS ERC20.sol

Need to understand the safeERC20.sol and ERC20.sol from openzeppelin I was reading the medium articles and unable to understand why safeERC20.sol has been used Please help me understand this Thanks
1
vote
1answer
73 views

How Do Sniper Bots Really Work?

If you ever traded in defi, you probably have seen coins getting sniped at the very second of their launch and drastically inflating the prices. I assume these bots are written in js, ad using web3 ...
0
votes
0answers
29 views

I accidentally sent uni token to contract address. Can i get it back?

Instead of transferring my Uni token to my binance wallet, tokens dropped to contract address. I tried to send my 400 uni tokens to my wallet in binance with the metamask wallet. but as you can see ...
0
votes
1answer
14 views

How to acquire ERC20 tokens on a test net?

I want to interact with a smart contract on Rinkeby, but I need to have ERC20 tokens to do so. I know how to get Ether on Rinkeby, but how would I get ERC20 tokens? Do I have to deploy and ERC20 ...
0
votes
0answers
9 views

Tool to find addresses owning a specific set of tokens

Does a tool (similar to etherscan or nansen) exist to identify addresses, which own a specific set of ERC20 tokens? I.e. Being able to find an array of addresses owning both the token $rook and $mta.
0
votes
0answers
13 views

Band ERC 20 from coinbase to Trezor missing [closed]

I sent Band ERC-20 from Coinbase to Trezor Beta. the tokens are not showing and the Trezor receiving address for Ether is not the same as the one Etherscan. I cannot find the tokens. Can someone help ...
2
votes
1answer
14 views

What is this allowance check in ERC20 transferFrom implementation

There is something i do not understand in this file: https://github.com/Uniswap/uniswap-v2-core/blob/master/contracts/UniswapV2ERC20.sol function transferFrom(address from, address to, uint value) ...
0
votes
0answers
10 views

Smart contract for create unlimited wallet and transfer tokens to parent wallef [closed]

I need to implement an payment gateway for my site users Each user have an unique wallet Transfer all tokens to parent wallet when received and call an page on my website But cant find any solution ...
0
votes
0answers
17 views

Returned values aren't valid, did it run Out of Gas?

I am getting this error even when I get the ABI of the token from etherscans website. Here is my code: require('dotenv').config() const express = require('express') const bodyParser = require('...
1
vote
1answer
11 views

How to create a snapshot of ERC-20 token balances?

Token holder snapshots are useful for airdrops, dividends and such. How to create one?
0
votes
1answer
31 views

Getting this error for TOKEN ABI: You must provide the json interface of the contract when instantiating a contract object

I am trying to get abi of a token with etherscan and pass the variable in to the web3 function. I am using etherscan's getabi built in function as it is shown in the API documentation but I am still ...
0
votes
1answer
20 views

TypeError: tokenContract.symbol is not a function

I am trying to get the token symbol for a certain ERC20 token with web3js HERE IS MY CODE //Token ABI var contractAddress='0xbcf9dbf8b14ed096b2ba08b7269356197fdd1b5d' const contractABI=[{"...
1
vote
1answer
26 views

How does “swap” work between ERC20 tokens? And what is “swap”?

What is "swap" presicely between ERC20 tokens? Is it exchanging one ERC20 token for the other without fees, in the most possible native way? How is it different from "convert"? Let'...
0
votes
1answer
17 views

Transaction reverted by EVM when using transfer from method

I'm using a method in which transferfrom method of an ERC20 token is called. In test enn I use my own ERC20 token and ganache and everything works fine. but in Rinkeby testnet when I use interface of ...
2
votes
1answer
34 views

Does Chainlink have an aggregator for its price aggregators?

I need a way to pass an arbitrary ERC-20 token symbol and get a price for it in return. The Solidity interface should look something like this: function getPrice(string memory symbol) external view ...
0
votes
1answer
26 views

Dumping erc20 token transactions via rpc?

I'd like to do dump all transactions of an erc20-token via the json-rpc interface. I've got a full node running but I'm lost, since the ethereum blockchain is harder to navigate than bitcoin for some ...
0
votes
1answer
11 views

Get contract address from contract creation transaction

I'm trying to detect the creation of new ERC20 tokens. My current idea is to scan all transactions in a block, and look for transactions where the "to" address is null. This is normally ...
1
vote
1answer
36 views

ERC20 optimization

I am studying popular Ethereum smartcontract's source code and there is something i do not understand on ERC20 standard. Let's took this example: https://github.com/OpenZeppelin/openzeppelin-contracts/...
0
votes
0answers
23 views

Running Ethereum Exchange (including ERC 20)

Would it make sense to run the app server and an Ethereum node on the same machine considering how closely they interact? Or should they be on separate machines to not affect each other? What is the ...
0
votes
1answer
28 views

Should I make separate ERC20 wallets for each token?

When I create an Ethereum wallet on my hardware wallet (Ledger Nano), or a web wallet (Metamask), is it possible to mix UNI token and ETH together in that same single wallet address? Or must a ...
0
votes
0answers
33 views

Uniswap fork: remove liquidity error

I am trying to fork uniswap. And I have a problem when liquidity is removed. Problem in UniswapERC20. I don't know what's wrong. Step by step (repeatedly for Rinkeby and Ropsten): Copy Uniswap ...
0
votes
1answer
21 views

why my Contract address 0 value on etherscan [closed]

Transaction Hash: 0xcacbecb6c8be10317e27784c7afd33fa52f43df6e31fcc4e0a253b274201bc56 Address 0x1B2cB9A600F80D8cDb529F8D448b9010B0C978c6
0
votes
0answers
13 views

Not quite ERC721 or ERC21

I have a problem that I'm really stuck with so I'm coming to the experts:) I have a personal project I'm working on. I'm minting tokens in large batches, once a condition is met, a new batch of tokens ...
0
votes
0answers
10 views

ERC20 interest/reward idea

trying to keep it short and clean. Create erc20 token with max supply. Have "master" address with tokens for distribution periodic interest/rewards. Automated distribution rewards 1st of ...
0
votes
1answer
23 views

Is ERC-20 specific to Ethereum

I have read a lot of informations about ERC20 tokens. What i want to know is : Does it exists some ERC20 tokens which works with another blockchain than Ethereum ? Or ERC20 is a specific Ethereum only ...
0
votes
1answer
13 views

overload standard erc-20 methods in solidity

Can I overload and use standard ERC-2O methods? For example: Standard function : transfer(address to, uint tokens) public returns (bool success) Overload function : transfer(address to, uint tokens, ...
0
votes
0answers
12 views

Is the function of transferring a fraction of ERC20 token going to work in smart contract?

For a ERC20 token with decimal=18, there are plenty of decimal to handle something like 10.234. Here is a function to transfer a percentage of a balance: uint256 public balance; //in token address ...
0
votes
0answers
16 views

Stuck ERC20 tokens appearing in a different contract

I have 1000s of token called ERC20 still stuck. I found them when trying to find missing SPANK on MEWconnect which only shows 1% of the SPANK I thought I had. If i select the spank contract on ...
0
votes
0answers
25 views

Simple Solidity Question - Gettting Error in IERC20(path[0]).transferFrom

I am trying to call a simple contract, which I created, from ether.js to swap DAI to USDT on KOVAN. Essentially, the sol function takes the passed array of address[] and is doing a transfer from ...
0
votes
0answers
15 views

Nethereum error: The program has exited with code 0 (0x0)

I followed the steps mentioned in http://docs.nethereum.com/en/latest/Nethereum.Workbooks/docs/nethereum-gettingstarted-smartcontracts-untyped/#deploying-smart-contracts Used the below sample code: ...
0
votes
1answer
29 views

Contract address payable issue

If i remove payable from: then i get this error with my receive function. Not sure how to fix this. I have an erc20 token contract that has a receive function and this contract inherits from it, that'...
2
votes
0answers
104 views

How to get token prices with UNISWAP API

I am using uniswap python api to get live token prices. I am using all the variation of the built-in functions. However, it does not give me the right value. HERE IS MY CODE address = "...
0
votes
0answers
18 views

What s the official gui developped by the Ethereum fundation? Does it allows to display erc20 tokens?

After losing access to my email address, I am asked by an exchange to show the deposit history for a specific coin (in that case an erc20 running on Ethereum) from a specific address (which I own the ...
1
vote
0answers
11 views

How to Accept an ERC-20 token as Payment for a Product?

First of all, this question was asked before here: Accepting ERC-20 Tokens as payment but I want to see if a better way has been developed to accept ERC-20 for payment, so I'm asking again. To ...
0
votes
1answer
8 views

Looking for specific kind of smart contract for my token [closed]

I am playing around with ERC20 token creation. Created one using this tutorial - https://www.youtube.com/watch?v=-Nje9ucd5rY Now I want to be able to : -Give away tokens. For example, when buyer ...
0
votes
0answers
18 views

How can I do it Erc20 Token Address Subscription

API listening to the transaction at the router address in the code below In addition, can I add the any token address on this router address for subscription? wss.on('connection', function connection(...
0
votes
2answers
27 views

Token Contract Verified and Signed on Mainnet Does Not Show MINT Function

The Token Contract Address https://etherscan.io/address/0xa2e7a0d1cfeda4d3977277265e205f6092d02e3b was successfully tested on Ropsten (See Ropsten Contract Address ...
0
votes
1answer
11 views

Preventing Transfer from Specific Address in ERC20 Smart Contract

We have a ERC20 contract. This contract is currently working. We want to make a change to this contract. We do not want certain addresses to transfer tokens. Is it possible to do this? How should we ...
0
votes
1answer
19 views

how to pass address(0x0) to remix?

I want my users call a function and send some deposit to contract. I want them to chose whether they want to send ETH or ERC20 tokens. I have my code and I see no flaw in it. but how can I pass ...
0
votes
2answers
73 views

Metamask (and other wallets) don't show tokens on balance despite of transactions are in blockchain

I've generated thousands of addresses with my seed phrase and deposited some USDT tokens to one of them (m/44'/60'/0'/267) and ensured that I'm able to spend that tokens. But after I've imported this ...
0
votes
1answer
18 views

Is there a way to approve all future erc20 tokens for a contract?

I wanted to write a Smart Will contract that basically sends everything in my address to a beneficiary's address if I die. However I don't want to send everything to the smart contract in advance ...
0
votes
0answers
10 views

Wbtc on ethereum

I noticed there are wbtc token on ethereum chain with 1:1 rate for bitcoin, which btc token is reliable and easy to exchange ? Which contract address? Thanks
1
vote
1answer
13 views

Before a transferFrom, is it better to check the allowance first?

transferFrom already checks the allowance, so does it make sense?
0
votes
0answers
13 views

Deploying ERC20 Error

I'd like to deploy follow "StandardERC20" token to kovan test net using Truffle. I want to deploy same contract like "https://etherscan.io/address/...
0
votes
0answers
24 views

Can someone help me get my funds back in my possession from a contract?

So first off, buyer beware: do not mess around with gameswap.org it appears I made a mistake in doing so. Luckily I never invest more than I can stand to lose unless I really trust the project. So not ...
0
votes
0answers
19 views

The allowence does not show the approved value with ERC20 token

An ERC20 contract was deployed in remix and here is the approve console output: status true Transaction mined and execution succeed transaction hash ...
1
vote
0answers
72 views

Why is the allowance 10**8 inside the test but equal to zero in the smart contract?

I'm running this test: def test_mint(prf, exValue, web3): wBtcAddress = "0x2260FAC5E5542a773Aa44fBCfeDf7C193bc2C599" ABI = [{"constant":True,"inputs":[],"...
1
vote
1answer
34 views

Who owns the ERC-20 tokens? [closed]

I am creating an Erc-20 token. I want to know whether the token will be owned by the smart contract at the contract's address or by me, the contract-deployer at my address? I want to know this because ...
0
votes
1answer
27 views

ETH transactions to presale contract keep failing

I'm trying to send some ETH to a presale smart contract on Kovan. Allowance has been set with presale address as a spender - with the exact same amount as the tokens allocated in the presale contract. ...
0
votes
1answer
21 views

Truffle Test AssertionError: error message must contain revert

I can't figure out why this error occurs Here my test js code: var YarockToken = artifacts.require("./YarockToken.sol"); contract('YarockToken', function(accounts) { var tokenInstance; ...

1
2 3 4 5
29