Questions tagged [tokens]
A token is a transferable, divisible object on the blockchain, such as a subcurrency or a prediction market share.
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Is it legal create an algorithmic trading cryptocurrency fund for social groups around the globe to pool in their money?
Is it legal create an algorithmic trading cryptocurrency fund for social groups around the globe to pool in their money? What is the viability of this project in terms of regulatory compliance?
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1answer
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Token migration and IDEX smart contract problem
During a recent token migration from token A to token B, a large number of token A were held by a number of people in an IDEX address (where it was ready to trade). The IDEX address is part of a smart ...
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1answer
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can etherscan.io show local ganache transaction details?
I am purchasing tokens on my sample Dapp with ganache-cli account using metamask.
Metamask shows the confirm message and deduct the ether from total balance but in token section it still not update ...
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How to set and get marketprice of token in contract?
I am building a simple erc-20 token. I don't have an idea as how token price is setup. However, I need to get my token's market price inside another contract. If you see this example of token BOMB, it ...
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1answer
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Custom token showing balance of 0 in MyEtherWallet
I made a new token on the Ropsten test network. Here's the contract address: 0x801fd9c17087ec868dc8540055b7ea3cb6dbbe34.
When I followed the instructions to add this custom token to MyEtherWallet (by ...
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1answer
46 views
error: VM Exception while processing transaction: revert SafeMath: subtraction overflow on migrating crowdsale conract
I am developing the token sale Dapp using openzepplin-solidity version 2.3.
While migrating, I got the following error.
Returned error: VM Exception while processing transaction: revert SafeMath:...
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Smart-contracts referencing each other [duplicate]
How would one retrieve these three addresses in the "Knot" smart-contract? I am very new to this, and would like to know whether this is even possible. The "Knot" contract should be able to reference ...
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1answer
27 views
What should gas prices be for sending out tokens?
I constantly get failed transactions when sending out tokens like USDT using metamask. I have my gwei set at 10 and the gas limit at 21000. I even tried gas limit set to 51000 and it still fails. ...
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Create multiple tokens for a unique property
here is the idea:
we assign a set of unique tokens to a company and then we allow people to buy some tokens and get partial ownership of that company. How can I achieve this? I was thinking of ...
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2answers
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Which erc token to use?
I wonder someone could give me some advice.
I am planning to work on a Ethereum project with a Solidity smart contract.
The smart contract should contain tokens which can be earned by a person by ...
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ERC-20 Token Transfer Error (Unable to locate Corresponding Transfer Event Logs), Check with Sender
EtherScan.io is showing error: The ERC-20 Token Transfer might have Failed (ErrCode: unable to locate corresponding Transfer event log), check with sender.
Transactions are successful and the ...
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1answer
24 views
Get ETH and Token Balances of Wallet address
How do I get a simple and fast balance of ETH and all Token owned/stored within a wallet address?
I have seen similar question and the closer answer was in this demo: http://wbobeirne.com/eth-...
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1answer
29 views
Wrong estimation of gas while contract deployment
I have a smart contract:
pragma solidity 0.5.3;
import "./ERC20.sol";
contract Transfer {
ERC20 private erc20iface;
address private _owner;
modifier validOwner() {
require(msg.sender == ...
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1answer
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Measuring elapsed time between user erc20 token transfers with lazy evalutation
So I'm learning solidity and wanted to make an erc-20 token after reading the solidity by example docs. Let's call the token T.
I would like to measure the elapsed time between two transfers of an ...
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2answers
41 views
Is there an ethereum android wallet where I don't have to manually add in tokens I have and just auto detects it?
Using coinomi or even metamask on chrome is quite annoying as I need to manually add in tokens I have in my account and it doesn't auto show up. Is there an android or desktop ethereum wallet that ...
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1answer
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Is Smart Contract of any ERC20 token is always available publicly
Is Smart Contract of any ERC20 token is always available publicly.
If not complete, then what things are generally available,(for eg, except some sensitive information)
And, if not any of them are ...
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1answer
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Is there a token standard that allow for future minting and burning of tokens?
I am interested in an ethereum token with the functionality for an operator to mint new supply at any time. It would also be nice if the operator could burn supply explicitly rather than sending to an ...
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1answer
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Parser Error - Creating EIP20 Tokens
function transfer(address _to, uint256 _value) public returns (bool success) {
require(balances[msg.sender] >= _value);
balances[msg.sender] -= _value;
balances[_to] += _value;
emit ...
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1answer
72 views
Percentage calculation
I'm currently learning how to write smart contracts.
While studying some code, I came across this line:
uint256 a = value.ceil(basePercent);
(with: uint256 public basePercent = 100;)
Then one ...
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1answer
35 views
ERC20, how to calculate how many tokens for crowdsale?
If you look at this article, the total tokens for crowdsale is 100 tokens and defined in the code as
uint256 public maxTokens = 100000000000000000000;
how come 100000000000000000000 becomes 100 ...
0
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1answer
30 views
Code A Contract To Accept A Different Token (Other Than ETH)
I'm developing a DApp for Decentraland that will accept payments in their ERC-20 token MANA. How can I code a smart contract to accept a token other than Eth? How can msg.value know the value of a ...
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Why should I use an ERC-721 token to store data instead of a Smart Contract
Taking CryptoKitties as example, I'm sure it's possible to achieve the same concept of Crypto Collectable creating new kitties as Smart Contracts instead of using Tokens. Which would be the ...
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2answers
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use the caller of the wrapper function to call the inner function
Suppose, I have 2 contracts A and B:
contract A{
function someMethod() public{
// Something happens here
}
}
And contract B containing its instance and its wrapper function
...
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2answers
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What is the latest implementation of approveAndCall() - Solidity ˆ0.5.0
Just curious for some background on approveAndCall()
1) Is it initially an ERC223 method ? or is it officially part of the ERC20 interface ?
2) Also Im working with an old contract so Im wondering ...
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1answer
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How do we communicate with contract functionality which is deployed in public test network using web3j [closed]
I would like to write a wepapp for security token contract which is deployed in public Ropsten Test Network using web3j. Need some idea.
Thanks in Advance
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How and Why other should buy and sell my ICO token? [closed]
When I invest or create a token, I am hoping someone in the future will want to buy it at a higher price. Why would anyone buy my tokens to use the platform if the price of the token keeps increasing ...
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1answer
27 views
How can I wait if it's not possible in smart contracts? [duplicate]
From my understanding, waiting in a solidity smart contract would create a total disaster for the whole Ethereum's blockchain.
I can see in some circumstances that solidity offers block.timestamp ...
0
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1answer
44 views
How to swap tokens?
Say I have a X token and Y token and I want to swap X tokens in exchange for Y tokens. How can i do that?
Its like during crowdsale, instead of using ether to buy the Y token I want to accomplish the ...
0
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1answer
57 views
Web3 Contract.balanceOf is not a function
I have read this helpful SO answer about sending ERC20 contracts, but it seems that the Web3 docs and API have changed dramatically since then. I am trying to get the balance of a smart contract using ...
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1answer
33 views
Create custom mobile wallet for my two ERC20 Tokens
I have two ERC20 tokens that I created on Ethereum.
I would like to know if it is possible for me to create a mobile application that will allow my users to check their balance (for tokens) and ...
0
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1answer
21 views
Manage a whitelist
I can see security tokens solutions like PolyMath keep the whitelist on the contract and allow transfer only after checking the sender and the receiver are on the whitelist.
What I'm not clear about ...
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2answers
59 views
Help with ERC20 Contract
I sent tokens to my contract address instead of to my myetherwallet address from an address that the tokens were previously sent some time ago. Now I have no access to the amount sent to this address. ...
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1answer
34 views
How are people using ERC20 to tokenize assets
Hey guys been looking a lot into tokenization of assets wondering how this is possible with ERC20 (Seeing a lot of people use it and keen to understand) how would you represent an asset with each ...
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2answers
38 views
How do I send NFT assets (ERC721 Tokens) from my Ethereum wallet to someone else?
I want to send my ERC-721 to my friend. Fast. Any suggestions?
2
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2answers
38 views
Splitting and Merging tokens
i'm here to ask if my project is doable or not.
I'm actually reading "Mastering Ethereum" by Andreas M. Antonopoulos, so i have some basic solidity knowledge.
I have a project:
I have a building, ...
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0answers
13 views
Want to understand token migration
Can anyone please explain the process of Token migration from one network to another network, Like omesi go and tron has done. they first lauch there own ERC20 token over ethereum and later migrated ...
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1answer
17 views
How to view or transfer initial ethereum smart contract balance?
I created a new smart contract token with initial supply and deployed it via MetaMask. Then I added this token into MetaMask but token balance is Zero.
Now, My question is when we create a new ...
0
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1answer
21 views
How to differentiate a smart contract from a common wallet?
Having an Ethereum address, I need to check whether it is a wallet or a token (ERC-20 contract).
How to check? (I need to implement it with Web3js.)
Ideally, it should also reject contracts which ...
0
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1answer
41 views
Is a contract verified and safe if it's created by a verified contract?
The contract source code is not verified as you can see in the picture, but the contract was created by another contract code which is verified.
Does that mean that the contract code from the picture ...
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1answer
16 views
Can I have a listener to cryptocurrencies / tokens reaching a specific address?
Let's say that there is an address called 0x1
There is another address called 0x2 which just released a new token called ABA.
Is there a way to constantly listen for 0x1 to see if it receives ABA ...
0
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1answer
140 views
Create an ERC20 Stablecoin [duplicate]
How to create a stable coin with an ERC20 token contract ? Does it require contract to be modified ?
Are there some good practices or standards ?
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0answers
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Accidentally sent REN (ETH token) to my ETH contract address using my Ledger Nano S. Can someone help please? [duplicate]
I sent REN (ETH token) to my ETH contract address by accident while using my ledger nano s. Can someone help me understand what's happened to the tokens and if I can retrieve my REN token from my ETH ...
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1answer
41 views
ERC20 token balance is always zero
I'm writing a pre-minted ERC20 token contract derived from openzeppelin-solidity like:
pragma solidity >=0.4.24;
import "../node_modules/openzeppelin-solidity/contracts/token/ERC20/ERC20.sol";
...
0
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0answers
35 views
how can I transfer ERC20 tokens from user address to other user address using web3.js and ethereumjs,
This is code I have used to send tokens to other account from token holder account. below code is working, transferring token from contract address.
Tokens: 500000
A Account having : 1000 Tokens
B ...
0
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0answers
28 views
Could we know if an address contains a specific token via Etherscan API?
I tried this, http://api.etherscan.io/api?module=account&action=txlistinternal&address=0x2c1ba59d6f58433fb1eaee7d20b26ed83bda51a3&startblock=0&endblock=2702578&sort=asc&apikey=...
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1answer
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linking the CoreContract and the ERC20 token contract
What is the standard way of making the link between our CoreContract and the ERC20Token contract used by the Core Contract? Are people used to use inheritance like: MyCoreContract is MyERC20Contract { ...
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1answer
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Staking of coins
I have a question on staking of coins.
Suppose there are 10000 tokens in a user wallet, and he wants to put 5000 tokens on staking for a certain time period (i.e That 5000 tokens should go to an ...
0
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1answer
25 views
Publish a ERC-20 based token in a private chain [closed]
What are the steps to follow if I want to publish a Togen generated token. Into a exchange platform. The goal is something realted to be able to buy my own token with real money, using a platform like ...
0
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1answer
67 views
Can't send ETH to ERC20 contract [closed]
I have ERC20 contract
pragma solidity ^0.5.7;
library SafeMath {
/**
* @dev Multiplies two unsigned integers, reverts on overflow.
*/
function mul(uint256 a, uint256 b) internal ...
0
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1answer
12 views
Why contract owner balance 1Token instead of 1000000 in Metamask
I made contract ERC20 token MTCZx
https://ropsten.etherscan.io/address/0xf9471198b6f9c364f41Ea66e9a3F8daA637Ee77C#code
which can sell MTCZx tokens for ETH.
When I deployed it I make query to ...
