All Questions
2,867 questions
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2
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How to peg value to token outside ethereum
I have an online game system. I issue some tokens through ethereum. How can I peg value of the tokens issued on ethereum to my game system, which is outside the ethereum eco system. (ie) The users ...
CommunityBot
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2
votes
1
answer
691
views
Fail to "buy" from Crowdsale contract wrapping an already deployed contract
Hi I am a newbie to the Ethereum development. I have successfully deployed a burnable, pausable, capped token contract (TC) on rinkeby test network, and was able to interact with it - minted and ...
CommunityBot
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0
votes
2
answers
522
views
Error message using transferFrom and transfer functions from ERC20 token
I have been trying to make my code work but I couldn't and wanted to know if you could help me or give me some advice :(
Here is my code in Remix:
And here written:
pragma solidity ^0.8.18;
import &...
CommunityBot
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0
votes
1
answer
26
views
I transfered coins to a neiro address but the contract addresses are different, can i retrieve my coins?
Token was transfered from one exchange to another but I later discover they are not of the same contract information even though they share the same network/block chain.
Can I retrieve such tokens?
2
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1
answer
478
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How do I obtain the transfer logs of an ERC721 token through Etherscan?
Is it possible to get the transfer logs of a specific ERC721 token ID using Etherscan API? For example, https://etherscan.io/token/0x06012c8cf97bead5deae237070f9587f8e7a266d?a=587058#readContract
I ...
CommunityBot
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0
votes
1
answer
3k
views
execution reverted: "ERC20: insufficient allowance" on transfer method (not transferFrom)
I'm developing a Smart Contract that transfer tokens that are owned by the Smart Contract itself. The function to do that is pretty simple:
pragma solidity 0.8.1;
import "@openzeppelin/contracts/...
CommunityBot
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2
votes
2
answers
1k
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ValueError: {'code': -32000, 'message': 'invalid sender'} when calling transferFrom using web3.py
I want to make a function that allows you to send tokens from one owner to another.
nonce = w3.eth.getTransactionCount(from_['address'])
unsigned_transaction = contract.functions....
CommunityBot
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0
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1
answer
550
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Token Price on Swap and CEX/DEX
My question is actually almost similar with this one :
How to keep the token price in uniswap the same with the centralized exchange
I want to know how to sync token price more deeply :
From the link ...
CommunityBot
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1
vote
1
answer
459
views
BSC token , time delay tax
I’m trying to have a rolling tax on a coin based on the amount of time since the last buy
I’m realizing that bots are buying and selling and scalping market cap due to low defi tax.
So what I’m trying ...
CommunityBot
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0
votes
1
answer
381
views
user api to exchange eth token and wallet address creating using code
Is there any API to help exchange ether or tokens online which will help in coding an exchange.
For bitcoin one can generate a wallet address, is it possible to generate a wallet address for Ethereum ...
CommunityBot
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2
votes
1
answer
482
views
How do I find my DBET tokens in MyEtherWallet?
I mistakenly bought DBET tokens directly from my Exodus wallet. I used the public key of Decent.bet (DBET). I assume I should be able to find/see my DBET tokens in MyEtherWallet, but I do not know ...
CommunityBot
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0
votes
2
answers
1k
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Developing a Staking and Un-staking Smart Contract
I am relatively new to blockchain, and trying to write a staking smart contract, which could stake any ERC20 token and gives APY in the same token with the following requirements:
Staking of ERC20 ...
CommunityBot
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0
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1
answer
430
views
Sending tokens from one Address to Another
I am new to this. So please no flaming.
I created a token on binance smart chain and i want to send from one Token address to another token address, here is my confusion, am I to use the Normal ...
CommunityBot
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0
votes
0
answers
23
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Funds USDT Sent via ERC20 to the Blockchain
I need someone to tell me if any of these statements from my BTC trading account are true?
First background I have an account that I was trying to withdraw funds to my crypto com account connected to ...
1
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2
answers
752
views
Is there any way to transfer ETH in a contract function just like transferFrom for ERC20 tokens?
I know that you can request an authorization and the transfer of ERC20 tokens from a contract user to another address with approval() and transferFrom().
But it here any equivalent to do the same for ...
CommunityBot
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0
votes
1
answer
791
views
Token id 0 minted error
i was wondering if someone can help me here.
I'm minting an nft by this smart contract, and the problem is that the tokenid count starts with id 0, and that is an error. It must start in id 1.
Someone ...
CommunityBot
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1
vote
1
answer
1k
views
Loading smart contract x with tokens; sending eth to smart contract x; receiving tokens for that eth
Hello dear Eth community,
I am a complete noob, please go easy on me ;) I am an IT teacher and I want to create a reward system for my class for a game that we play weekly. The game is not ...
CommunityBot
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0
votes
1
answer
643
views
Send ERC20 token from a forwarder contract address to another address
I am having difficulty spending the funds in a smart contract address.
The smart contract address was generated using an ETH forwarder smart contract - https://github.com/primozkocevar/SigWallet-ERC20/...
CommunityBot
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1
vote
1
answer
1k
views
transferFrom error. Exception thrown in smart contract transaction
I compiled smart contract in solidity on remix.ethereum.org. I made account via MetaMask and want to let other addresses send tokens to themselves using ropsten network. I mean - I am contract owner = ...
CommunityBot
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1
vote
2
answers
1k
views
MyAdvancedToken Automating Selling and Buying function not working
I attempt to create a token with the "automatic and selling" function as describe here. After having copy/paste the code (footpage)and deployed the contract no error message appears. But when I ...
CommunityBot
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0
votes
1
answer
38
views
Storing ETH on token address
I like to create a token contract which can be created via ether transfer and also redeemed back to ether. Is it a good idea to store this ether on the contact address, or are there more secure ...
- 93
2
votes
2
answers
3k
views
How this honeypot token is able to fool the checkers? How does it figure out how the transfer function is called - via mined or simulated transaction?
I'm developing a scanner/checker for honeypot tokens and I was using it for a few days now to scan the BSC network. While using it I keep stumbling on one particular design many times a day, which is ...
CommunityBot
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2
votes
2
answers
2k
views
How can I find the block where a user enacted a certain event on a contract?
I'm trying to build a web3.py program to take in a given user's address, and return the amount of ETH traded since they added liquidity to a Uniswap exchange. Uniswap is a smart contract on the ...
CommunityBot
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0
votes
1
answer
584
views
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 ...
CommunityBot
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3
votes
3
answers
15k
views
How to fetch ETH/USD price from the coinmarketcap api
I want to fetch the current ETH-USD price from this api (https://api.coinmarketcap.com/v1/ticker/ethereum/?convert=USD). How do I fetch just the price into a variable in PHP for reuse on my ...
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0
votes
1
answer
395
views
ETH wallet issues
I use Coinomi wallet and everything was ok untill I tried to add my wallet to another system like MEW and Metamask
I use same recovery phrase but I end up with different account with no money there. ...
CommunityBot
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0
votes
2
answers
850
views
Can an ethereum token name have numbers in them?
So let's say a token is called USDC. Well can we have one called 1usd or 43g something like that? Or must they all be uppercase letters. Thank you.
1
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2
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2k
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transferFrom function doesn't work
I have made a simple ERC20 token smart contract, but my transferFrom function does not work. I keep getting "Note: The constructor should be payable if you send value." even if I declared it as ...
CommunityBot
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0
votes
2
answers
377
views
How can I parse internal transactions with light node?
is that possible to receive all transactions from new block with light node and parse all and even internal transactions with the help of its api?
CommunityBot
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1
vote
3
answers
809
views
Using Openzeppelin's crowdsale contract as a base, how can I set the rate to be a decimal number?
For example if rate = 10 then for every wei the buyer gets 10 "token units" which are each 1*10^18 of a full token (as the default decimal for the erc20 token is 18).
If I want the users in a ...
CommunityBot
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0
votes
0
answers
15
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I got scammed by Robot [duplicate]
There's APP called ETH MINER ROBOT. I withdraw 0.1ETH to my Binance Account and never received it.
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0
answers
11
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I got scam from one pretty girl she told me invest USDT up to 5k and earn daily profit, refer this website, "ogfvs.top" ETH-ERC_20 [duplicate]
I got scam from one pretty girl she told me invest USDT up to 5k and earn daily profit, refer this website, "ogfvs.top" ETH-ERC_20 by using this website, and i lost my USDT 4600 recently, ...
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2
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1k
views
Token Swap from USDT (erc20) to eth
Can I swap my USDT (erc20) to ethereum with eth charges?
CommunityBot
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1
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2
answers
637
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How to create a token exchange for private blockchain?
I have requirement to create a exchange for my private blockchain tokens, where registered user can buy and sell tokens, and token price goes up and down on demand and supply.
I have searched bit, ...
CommunityBot
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6
votes
2
answers
2k
views
Smart contract erc20 code snippet to prevent buyer token transfers
I´m going to start a token pre-sale and I want to be able to send the tokens to the buyer but prevent the buyer to send tokens to another wallet.
I tried the following in my ERC20 smart contract but ...
CommunityBot
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0
votes
0
answers
18
views
Private Node Network-GoEth
i am trying to install private network of three nodes on my single laptop.
i did following:
install go-eth.
used a medium article and followed instructions
when i try to connect nodes with each other,...
1
vote
1
answer
47
views
Swapping tokens from pancakeswap
I am having trouble executing the swap on PancakeSwap. I always encounter this error. Can someone please check my buy function and tell me if anything is missing?
ERROR - Unexpected error during token ...
- 1,374
1
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2
answers
1k
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How to transfer ERC20 tokes from Blockchain wallet to MyEtherWallet?
I got some token and by mistake sent them to my Blockchain ETH address. Now, what is the process of transferring them to MEW? They talk about exporting your private key, what does that mean and to ...
CommunityBot
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0
votes
1
answer
18
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Can someone spend native Ethereum from a signer's address using just a signature?
I'm exploring Ethereum's cryptographic features and wondering if there’s a way for someone to use a signature to spend native Ethereum (ETH) from the signer's address without directly requiring the ...
- 5,766
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3
answers
399
views
CrowdSale basic contract sample showing Gas limit error
Hello I have copied Basic contract from official website https://ethereum.org/crowdsale
I'm beginner in Solidity and Ethereum development
It was successfully compiled by Remix but when I click "...
CommunityBot
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0
votes
2
answers
597
views
Forbid ERC20 tokens transfer
I have token smart contract that is ERC20 compliant. It is now transferable via any software like MyEtherWallet and similar. I wondering is it possible to forbid token transfer and allow it only using ...
0
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1
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480
views
Check historical balance of ERC20 tokens of wallets
I'm currently working for an audit company and one of the things that I'd like to know to expedite/speed up the process regarding cryptocurrencies is that would there be a way to check historical ...
CommunityBot
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0
votes
1
answer
483
views
Contract not showing the name, symbol, and supply
I am not able to see the name, symbol, and supply on the smart contract at ropsten.
pragma solidity ^0.8.0;
contract MyToken{
address public minter;
mapping(address => uint) public balance;
string ...
CommunityBot
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1
vote
1
answer
1k
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ERC20 tokens in Metamask suddenly not showing
I've been using Metamask in Chrome for a while and had a list of ERC20 tokens in Ropsten network already added in the Assets section through their contract addresses:
DAI address: ...
CommunityBot
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3
votes
2
answers
3k
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Constantly getting "Gas estimation failed" error when attempting to deploy ERC20 Token contract on Rinkeby testnet
I have included the code for the contract below. The error I get when attempting to deploy in remix via metamask is:
Gas estimation errored with the following message (see below). The transaction ...
CommunityBot
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0
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1
answer
524
views
I need to know how to set a maximum buy limit per wallet
Yeah so I'm creating a eth token and I need to find a way that buyer have a purchasable maximum limit. Can anybody help me with that ? Can't find answer thanks a lot.
CommunityBot
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0
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1
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2k
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How to go from v3 to v2 on Uniswap?
There are tokens that offer a better exchange rate in version 2.
Uniswap used to offer a friendly way to switch between versions.
CommunityBot
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0
votes
0
answers
44
views
How to identify swap transactions?
Is there a way to identify all swap transactions of a token pair?
So this would involve CEX, DEX, direct swaps, and other forms I am not aware of.
Of course, this can be complex involving many ...
- 101
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2
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2k
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How to fetch tokenURI from Polygon smart contract?
I am trying to analyse different tokens in terms of the metadata they link to. I found a Polygon-based token project: https://opensea.io/assets/matic/0x50c2eae4903261b386c27c1733588e867f1a33db/10200
I ...
CommunityBot
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1
vote
2
answers
548
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Need help implementing Burn Logic in an ERC-20 token
I am learning solidity and have decided to program my own ERC-20 token. I have inherited the ERC-20 Open Zeppelin standard, but would like to add some functionality that calculates 5% of every ...
CommunityBot
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