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A token is a transferable, divisible object on the blockchain, such as a subcurrency or a prediction market share.

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why out of gas when gasLimit is not reached

https://etherscan.io/tx/0x43f39829b3a48c4146808b12489e01bdb5dfa32d5b49514298339a719e538c09 this tx failed, and the msg shows the cause is: out of gas, but Gas Limit is 520000, while only 86056 Gas ...
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1answer
14 views

Wrapping ETH calling the WETH contract

I am trying to automatically wrap ETH when a user deposit ETH on my dapp. Therefore I am trying to call the WETH contract (on the Kovan Testnet for now). I wrote this code : WETH9_ WETH = WETH9_(...
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0answers
10 views

How does the initial token distribution look like on the blockchain?

How to identify the initial token distributions for this token? Where to find them and how do the transactions look like? Also, is it possible to identify who contributed to receive the ERC20 tokens?...
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2answers
11 views

set transaction limit for each token

Is it possible to set a limit for the number of transaction each token can have in solidity? for example, a token can only transfer 10 times.
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0answers
11 views

Not able to view Token Transfers Using Infura and Web3? [duplicate]

I am trying to get insight into token transactions for various smart contracts using infura and web.py. The following snippet of code I thought should return me transactions for that contract, but I'm ...
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0answers
16 views

Need help with Minted Crowdsale and Mintable Token

I am trying to do Minted Crowdsale with Mintable Token using Openzeppelin Solidity. This is the code I have got so far. Token.sol : pragma solidity ^0.4.24; import "./Ownable.sol"; import "./...
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1answer
18 views

How to add ICONS to our tokens on test network? [on hold]

I have seen several questions about adding icons to the existing Tokens in main net. But is it possible to add icons and other information to tokens on test network ?? ((just for testing purpose)...
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1answer
16 views

How do Token tramsfers, the associated token contract transactions and ERC20 token txns fit together?

Looking at Quantstamp token as an example it contains a list of transfers: Similarly the associated contract also has "Transactions" and "Erc20 Token Txns", however they all seem to be different. ...
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1answer
7 views

Extremely low token supply after token created on Tokenfactory via Metamask

I used the parameters in the picture below to create a token for our organization, but instead of showing the desired token supply of 1000000000 & 18 decimals (similar to, say, the MDT token for ...
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2answers
20 views

How to send multiple ERC20 tokens

There are about 2k ethereum addresses I'm supposed to send my ERC20 token to. Doing this manually is a no no. I've searched to and fro to no but most of the tutorials are not detailed enough. So can ...
0
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1answer
22 views

How to get data from a smart contract by asking a node for it? [on hold]

I want to call a function from a smart contract that just returns data and doesn't change nor add anything to the blockchain. I've read that since i'm not altering the blockchain data, it isn't ...
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2answers
22 views

The last line (line 247) in my ERC-20 code has a “ParserError: Expected Pragma, import directive or contract interface”. How do I solve this?

What measures do I take to solve this? I am currently on Compiler version 0.4.24 and this error shows up multiple times in my code which I solved by inserting a bracket. Now it is at the end of the ...
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1answer
27 views

What is the reason for not just issuing a token on the testnet (e.g. Rinkeby) for your token so that Gas costs are free (Rinkeby ETH from faucet)?

If someone wants a token to be usable and easily transferable between users, without the prohibitive costs of paying for gas every time with real ETH (and thus, money), why not just deploy it on ...
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1answer
21 views

Asset Tokenization: How to issue security tokens for different companies and trade them on the same exchange market?

Premise: I’m still learning here so I apologize if my question is too basic. Let's suppose that someone is developing a digital market for equity shares using blockchain (because it could save huge ...
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1answer
13 views

What does this error mean and can someone please provide the answer? It keeps saying Parser error on the burn function

Click Here for the image. ` pragma solidity ^0.4.25; contract owned { address public owner; function owned() public { owner = msg.sender; } modifier onlyOwner { ...
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2answers
28 views

Possible ways of verifying the ownership of Ethereum address when user lost its private key?

I am working on something that relates the ownership of the ethereum account address. I have a situation depicted as follows: Someone issues a token and issuer KYCed(off-chain) my ethereum account ...
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0answers
19 views

Smart Contract: Automatically trade/convert an ERC20 token to another ERC20 token

I'm trying to find out how a smart contract could be developed that makes a simple trade from one ERC20 token to another ERC20 token. The intention is to reduce required interactions from a user-...
0
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1answer
27 views

How Do I Get List of Transactions for Specific Token(s) using Web3? [duplicate]

I'm trying to pull together a dataset on various token transcations using the web3 module in python. However, being new, I'm confused by how to subset the blockchain information to a specific ...
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1answer
19 views

Is it possible to burn the balances of a contract from another contract?

Imagine the scenario in which contract A has in its possession 1000 tokens (of the contract itself). is it possible to create a second contract and burn the tokens of contract A? contract ContractA ...
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1answer
26 views

How to transfer tokens from Contract to Contract Creator?

FTF I'm a noob in Solidity! Has been created a contract sending the initial supply to the contract address. I would like to know if is it possible to send the tokens from the contract to the address (...
0
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1answer
8 views

How to incentivize a smart contract DApp without issuing a native token?

Premise: I’m still learning here so I apologize if my question is too basic. My understanding is that technically a smart contract could be built using Ethereum blockchain... no need for native ...
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2answers
36 views

Is ERC721 an appropriate standard for managing licenses?

In my example scenario, I have an e-commerce dApp where e-books are sold. I originally thought that I could represent licenses to access these books using non-fungible tokens (NFTs) through the ERC721 ...
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1answer
20 views

My Transaction is pending for over 20 hours now - initiated a call to the transfer function using Web3

I'm making a call to the transfer(address _to, uint256 _value) function within the contract through Web3. Here's my code; var Contract = web3.eth.contract(ContractABI); var ContractHandle = Contract....
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1answer
40 views

multiple transfer?

First of all, hello. we will write a token for a project we have developed. We are creating new tokens, we want to write a simple contract on remix ethereum. We will distribute a large portion of the ...
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1answer
18 views

Can security tokens (ST-20) and utility tokens (ERC-20) exists on same blockchain?

I am trying to build a dApp in which the functionalities of the dApp can be accessed by utility token but in the same app I wish to tokenize the securities as well. Can my utility tokens and the ...
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1answer
36 views

Deploying contract with parameters using web3.js and Node.js

I try to deploy a ERC721 contract. Which is from OpenZeppelin. My contract constructor wants two input string fields. constructor(string _name, string _symbol) public { name_ = _name; ...
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1answer
37 views

Use of the “indexed” keyword and token standards

Long story short, while making a blockchain crawler that would extract all ERC20 transactions I learned the hard way that ERC721 has the same "signature" as ERC20 (and probably many others that I ...
5
votes
1answer
1k views

Someone sent 0 ETH to my contract and got 134100 tokens

we have just finished a phase of our ICO and we were looking among the transactions. Someone managed to send 0 ETH to our contract and in return got 130 000 tokens. How did he do that and how ...
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1answer
29 views

Simulating DAO recursive/reentrancy attack

Trying to simulate the attack. In my attack contract: function attack() public { target.call(bytes4(keccak256("withdraw()")),amount); } function() payable public { if (msg.sender == ...
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0answers
19 views

Calling ERC223 both transfer functions fail

Given the contracts below (unnecessary code omitted), my tests fail when trying to call the ERC20 transfer() or ERC223 transfer() functions. Why is this happening? Both give Error: VM Exception while ...
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2answers
77 views

What’s the block reward for smart contract miners?

Maybe this is a basic question, but I can’t figure out what are the block rewards and/or transaction fees for miners of smart contracts . When talking about a cryptocurrency, the block rewards are new ...
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1answer
22 views

from token transaction detail, how can I know if token is actually transferred?

I am implementing support of multiple tokens in my application. I want to listen new token received transactions. I got that I need to decode the input data in any transaction to get the toAddress ...
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1answer
10 views

How to safely and quickly identify a privileged transaction within a smart contract?

I'm running a crowdsale for dogs and cats. If you're a dog, you can earn my token (TKN) at 1 ETH per TKN. But, if you prove you're a cat, you can earn TKN at a rate of 0.1 ETH per TKN (meaning you get ...
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0answers
16 views

Is there a way to use etherscan API (or another) to get a history of transactions for a specific ERC20 token for an ethereum account?

I want to be able to display the complete history of our token transfers in and out of users wallets. Is there an easy or established way to do this?
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1answer
24 views

How do I define my token to pass truffle test?

After running truffle test i get the following error: Zanes-iMac:xyztoken zanemassey$ truffle test Using network 'development'. Compiling ./contracts/Migrations.sol... Compiling ./contracts/xyzToken....
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0answers
36 views

How to generate a raw transaction and sign it with a private key and output the signed transaction with web3js 1.0? [duplicate]

I'm using a html file to try and test out methods on web3js. I want to be able to transfer tokens but first I need to be able to generate a raw Tx, sign it and output the signed transaction. How ...
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1answer
14 views

Truffle test failing due to different data type than expected

I am using truffle and ganache to make a token demo for myself. I'm following this guide then making my own changes according to my project. When I try running tests to verify that my contract is ...
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1answer
20 views

Is it possible to check a token transaction history for an account with web3js?

If I have an account that has sent and received specific tokens, say ExampleToken (EXT), can I use web3js to see a list of EXT transfers and receipts for my address (or any other address)? I am ...
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0answers
13 views

What is a “Buffer” in web3js and why is it required to send a token via a raw transaction over web3?

I am trying to use web3js to send tokens via a simple web interface. From what I can see this requires using a "raw transaction" and sendSignedTransaction() function. In the example in the ...
0
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1answer
13 views

ETH transfer help

Hi I have opened my first coin wallet - metamask. I have bought ETH through here and now tried to send to Binance to buy BAT. I just wondered how long it usually takes to transfer ETH as it seems to ...
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0answers
26 views

Help developing proper mental model of tracking physical assets using a blockchain

I'm struggling to develop an accurate mental model of using a blockchain to track physical assets. Given this I ask for patience from the community as I recognize my wording or thought process might ...
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1answer
21 views

The Token sale contract is returning an exception everytime. Tested on ropsten and there it is working fine

The below is the code for The token: pragma solidity ^0.4.16; interface tokenRecipient { function receiveApproval(address _from, uint256 _value, address _token, bytes _extraData) external; }...
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0answers
20 views

Contract deploys fine on Kovan, fails on Main Net. Gas too low or what?

I'm deploying a contract using its bytecode in wallet.ethereum.org. I deployed it on Kovan and it went very smooth and fast, fee was 1782250 gas @ 4 Gwei price. With the exact same bytecode, I tried ...
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0answers
8 views

Member “times” not found in contract creation

I'm attempting to create an ERC contract, although when trying to deploy inside remix, I'm getting the following function that sends tokens: function dispenseTokens() payable whenSaleIsActive { ...
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1answer
15 views

token value based on date?

I'm currently in the process of deploying a ERC20 token with my symbol being CLC, and wondering if it's possible to change the value of the token based on the current date? Basically splitting the ...
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1answer
26 views

Web3 - Getting variable value from deployed contract without ABI

I'm trying to build a wallet capable of managing ERC20 tokens added by the users, using Web3 1.0.0-beta.34. After adding a certain token to the wallet using its address, I was able to fetch the amount ...
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1answer
33 views

How to transfer Ether to ERC20 token contract?

I have a function that needs to make transfers to a token smart contract as well as personal accounts upon satisfaction of some conditions. function completeSale() onlyOwner public { if (...
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0answers
25 views

Error encountered during contract execution [Reverted]

i have created this contract https://etherscan.io/address/0xfecf0e91a193e8511ac83d8effda34ae4278f491#code but the problem is when i try to contribute to crowdsale it showing an error, (Error ...
1
vote
1answer
40 views

personal_sendTranaction for token tranfer return hash but transaction isn't found in the blockchain

I am using Geth as a provider to the blockchain. I perform JSON-RPC method send_Transaction to transfer tokens, it returns me hash of the transaction but I can't see this transaction in the Etherscan. ...
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1answer
16 views

Internal Token Transfer without ETH fee

Need to move all token from one address to another address(Internal) without fees. Could you please help me to solve this?