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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Ethereum ERC20 token at fixed value [duplicate]
I am new on this area. I am trying to create an ERC20 token with a fixed price per token such as USDT.
In other words, there is any way on the contract to issue my token to establish a constant price ...
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Max possible ERC20 Tokens allowed with 18 decimals?
I would like my token to have the maximum possible amount of tokens issued as a novelty. I would like to use 18 decimals standard ERC20 token, what value can I put in to get the maximum amount of ...
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ERC20 Shared Token Wallet
I want to know if there is there a way to have a shared wallet where 2 users both have to agree before calling "transfer". Any problem with this logic in the transfer method?
User A wants to transfer ...
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How to buy GNT tokens using myetherwallet
this is my first time buying Ethereum tokens on mainnet. Probably I am doing something wrong, so I am willing to hear any comments or hints about this process. My ethereum address on mainnet is https:/...
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How to send token ERC20 in 1 line of code on Ubuntu
I know now how to get balances of Token with sudo geth --exec "eth.call({to: '0xad408ef944da873fe9b65f4e78e21ac2d489db90', data: '...
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How can I get token info by the contract address?
0x5a65585ce8213d1c9433e63d53d4e468540a5019 is my CRC20 token. I can search the token info on etherscan. https://ropsten.etherscan.io/token-search
Token Attributes Found:
totalSupply = 100
name = ...
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Trouble receiving erc20 tokens on MyEtherWallet.com
I'm attempting to withdraw siacoin to a MyEtherWallet.com address accessed via a Trezor with 1.5 firmware.
The same address is storing a good amount of GNT.
Bittrex won't let me do the transaction ...
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Web Server Listen For When ERC20 Token Transferred
Is it possible to have a web server listen or know when a transfer has been made on a particular ERC20 Token Contract?
From what I researched, we are not able to make a HTTP request inside the ...
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Why don't I see my tokens in Mist?
I think I should have several tokens in my account, but I can only see Ether. Is a wallet contract necessary to see ERC-20 tokens?
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Is ERC20 Token Contracts the Only Way to Create Custom Tokens?
Is the only way to create your own tokens/cryptocurrency on Ethereum by deploying a Smart Contract following the ERC20 standard?
After deploying the token contract, is the only way to transfer the ...
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How to exchange between ERC20 token and ETH automatically
I've created an ERC20 token. Now I want to use this token. Is it available to swap between ETH and the token automatically like the followings?
What I want:
UserA send 1 ETH to the token owner's ...
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Web3 sending custom tokens by using the transfer function. Need to set the from account
Looking to code WEB3 to be able to send custom tokens out programmatically.
However, I am not sure where to specify the user account that actually sends the token.
This is the code I have thus far. ...
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Can ETH be shifted within the Ethereum Wallet into an established ERC-20 token without fees?
I have watch token accounts for various ERC-20 tokens within my Ethereum Wallet. Is it possible to send Eth to any of these token accounts within the wallet that would increase my token holdings ...
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Changing supply of an issued ERC20 token?
If I was to create my own ERC20 token, would I be able to change my token supply down the line? What other solutions let me adjust token supply if ERC20 isn't an option?
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Why does the compiler keep asking me to declare internal functions?
I am using this ERC223 compliant code to accept an ERC20 token as payment (provided by @aviral agrawal). Why does the compiler keep asking me to declare the balances function? I thought it was an ...
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ERC20: Why the specification uses 2 transactions for transferring token?
I was going through ERC20 lately and came across 2 level transfer protocol:
approve - Allow receiver to debit x tokens in n transcations
transfer - Transfer y tokens: y * n <= x
Why this was not ...
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Is erc20 token infinitely divisible?
"Bitcoins are only divisible down to 8 decimal places If there is a need for them, additional decimal places can be added with hard fork."
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I am interested in creating a new token and have a few questions
The question is, how can I implement a feature in the smart contract that can keep track of all stakeholders. The reason I ask is that I would like the contract to pay out dividends. So far, the only ...
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Will contract selfdestruct also return tokens?
If I have tokens assigned to a smart contract, will "killing" the contract send leftover tokens to the owner of the contract? I know that remaining Ether stored in the contract is sent to owner in ...
eth♦
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transfer function in ERC20 token returning false
I've created a test ERC20 token like at https://theethereum.wiki/w/index.php/ERC20_Token_Standard. I've sent some test ether to the contract and can verify my account has some of the token, eg with ...
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Ethereum token divide value by 10^18
I've recently found that the value of token transfers are in 10^18 hex value.
For example, in this event, the hex value of the token transfer is ...
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Crowdsale contract and safe withdrawals
According to crowdsale contract at https://www.ethereum.org/crowdsale tokens are transferred to a user account when "function () payable" is called by using external function tokenReward.transfer(msg....
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How to get an ERC20 token listed in etherscan.io
In etherscan.io, under the TOKEN drop down menu, there is a list of tokens,
and it is indicated that they all are ERC20 standard tokens
1) How do they get listed? Do we have to register a new ERC20 ...
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How to issue tradable tokens?
After deploying ERC20 tokens on testnet I realize I need a buyToken function in the Smart Contract in order to give tokenholders a way to buy the tokens. Another alternative would be to transfer all ...
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How do I create a crowdsale that only accepts a specific erc20 token?
Let's say you've created and issued an ERC20 token. You then create a crowdsale and only want to accept the token you issued, not Ethereum.
Is this possible?
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Why is this test failing with an invalid opcode error at the transferFrom() call?
I get the following error:
1) Contract: Bencoin should send Bencoin correctly via transferFrom(address, address, uint256):
Uncaught Error: VM Exception ...
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On-chain text encryption using Whisper protocol
Could one send a 10-character encrypted message within an ERC-20 transaction using the whisper protocol ON-CHAIN?
Or could that only be achieved by running private nodes and setting up a p2p server? ...
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What denomination should I issue my ERC20 token by?
Following the "Create a cryptocurrency" tutorial on ethereum.org, I ended up with the following function (stripped down):
function () payable {
if (msg.value == 0) { return; }
uint256 tokens =...
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tokens generation in smart-contracts specific to one asset [closed]
I have been building a smart-contract for tokens for songs such that they are specific to different songs such that one token is only valid for one specific song not other. Ive made a smart-contract ...
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Multiple Token Classes Within One Contract for ERC20 Standard
Is it possible to make one ERC20 compliant token contract, but have different classes of tokens circulating under the same token name?
e.g. You are distributing concert tickets validated by a token ...
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How does Solidity deal with < 0.0001 ETH?
I have an ERC20 smart contract that allocates tokens to each user based on the amount of Ether it receives. I have added explicit checks to ensure any transaction with msg.value < the minimum token ...
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Will it ever be possible to group multiple ERC20 tokens into a single transaction?
Specifically, if I wanted to send multiple different tokens to a smart contract, but it was important to the contracts function that all tokens arrive at the same time, could I put;
20 Token A
45 ...
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What's the point of returning a value in a non-constant function?
As we know you can't get the return value of a non-constant function
Still ERC20 does this a lot, for example:
function approve(address _spender, uint256 _value) returns (bool success)
Hypothesis:...
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ERC20 Token and effective way to store dividends
I want to create a token that will allow an effective way to iterate through and update dividend values per token holder address. With my current idea, I'd have to manage 2 structures to keep ERC20 ...
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Best way of accepting ERC20 tokens in my service
I need to allow users to deposit and extract ERC20 tokens in my service, and I'm wondering what's the best way of implementing that. My idea is to generate an account for each user, and when a user ...
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How would I start for such a code?
How would one attempt to make a contract as the one drawn under:
To elaborate, an ICO happens. The conditions of the ICO are that there are x amount of ICO tokens. x minus y amount is sent to a list ...
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Is an ERC20 token more of an 'IOU' token or is it capable of being a stand-alone crypto?
Say someone was to launch an ICO on the ethereum network. The token created, would that be better as an 'IOU' until I make a cryptocurrency to replace this one (due to ETH fees), or would it be ...
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Using Solidity, how can I execute the transferFrom function of an ERC20 Token?
I am trying to accept ERC20 Tokens as payment in a contract. As I understand it the sender will have to use the approve function to give my contract an allowance first. So far so good. What I do not ...
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ERC-20 tokens and freezing accounts
For the compliance reasons I need to implement account freeze functionality in ab ERC-20 token. Initially, issued tokens are not transferable until the address holder goes through Know Your Customer ...
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Is a stand-alone wallet for an ERC20 compatible token a possibility?
Assuming that there is an ERC20 compatible token deployed on the Ethereum blockchain, is it possible to:
1. Have a stand-alone wallet solely for this token (not an Ether wallet + watching a token, but ...
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Where is the ERC 20 token code?
I've read about and understand the idea behind the ERC20 Token Standard, but is there an official contract people can download and use? Or is it an official list of functions a smart contract should ...
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Is there an official source of info and decision-making about the ERC20 Token Standard?
I have been trying to trace information about the ERC20 Token Standard to an official source, and everything seems to go back to the (now closed) github thread where the standard was discussed and ...
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What is a summary of the token standard debate?
I've been seeing some talks about replacing ERC20 with a better standard. I think I'm slightly out of the loop, though.
What is, in summary, the limitations and/or issues with ERC20?
How will the ...
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Buy Gnosis tokens with geth
How to participate to Gnosis pre-sale using geth javascript console?
In gnosis official blog is described how to do it using parity but there's no information on how to do it using geth.
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Can my Ethereum Based Tokens / Coins be traded on a crypto currency exchange?
I am building my own Crypto based on Ethereum Blockchain. Is it possible for this newly created currency to be traded on any crypto currency exchange?
And secondly, will my new currency be compatible ...
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Process of getting a token on an exchange? [duplicate]
Does anyone know what the typical process of getting a token on exchanges is?
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Does an API standard for price feeds exist?
The ERC 20 defines a standard interface for designing a token contract. Does a similar standard exist for defining feeds that can be called by other contracts?
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Migrating a token from Counterparty to Ethereum
I am having a token in Counterparty blockchain and I'd like to migrate it over to Ethereum. The token is currently being traded on some of exchanges.
What strategies there are to take here? Are there ...
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Detect or verify reception of ERC20 tokens by contract
I'm looking into writing a contract that can accept an (unknown in advance) ERC20 tokens, from several different users. Is there a way to detect, or at least verify, that a user has deposited the ...
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Is it possible on Ethereum to create a token this way?
Can I make a token using Geth or another Dapp or method and meet these conditions:
a) I should be able to create the token conveniently without too much programming involved
b) I should be able to ...
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