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May I transfer token address to ERC20 of openzeppelin's lib

For using openzeppelin's ERC20 one can tansfer token info by constructor. But for token making by myself, it seems not work. I can use something like ERC20(token address).burnfrom(...) for Public ...
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0answers
6 views

Is ERC777 and Uniswap drama resolved?

Reference https://github.com/OpenZeppelin/exploit-uniswap Apparently, an years ago, there was reentrancy exploit on uniswap that was caused by ERC777 functionality: "Technically, the main logic ...
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0answers
13 views

Measuring gas cost -- returning gwei instead of wei?

I have an expensive function I am calling in my smart contract, and I need to keep track of the approximate amount of gas its consuming, so I measure gas remaining at the beginning of the function and ...
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0answers
10 views

walletconnect and metmask on mobile pre transaction confirmation eventError

I am using a local dev test node and connecting my daap via walletConnect. i am having issues with all transactions where they throw the following error : Error: Internal JSON-RPC error. at events....
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1answer
18 views

What are the 0x testnet endpoints?

I’m trying to test the 0x REST api, and can see the endpoints for the main nets, but what about the test nets? Specifically interested in endpoints for Polygon Mumbai and Goerli
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1answer
13 views

HELP I have root:"REVERT opcode executed. Message: 2"

pragma solidity ^0.8.6; contract Contract1 { uint index; address owner; uint256[] values; mapping(uint => address payable) addresses; constructor() { ...
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1answer
23 views

How to compile OpenZeppelin's ERC20 smart contract using solc? [closed]

I want to compile ERC20 implementation from OpenZeppelin in my own project. For this purpose, I put several files into the erc20/src directory. ERC20.sol (the file I want to compile) is located in ...
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0answers
16 views

How is EtherScan Built? [closed]

I am a dev and I really want to learn more about Ethereum development. So I want to build something similar to the EtherScan website for learning. Can anyone tell me how EtherScan does it? Do they run ...
0
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1answer
24 views

Can't receive any ETH for Rinkeby test Network?help? [duplicate]

I've tried linking the twitter tweet asking for funds into a Metamask Rinkeby wallet for testing practice purposes. If anybody on the Rinkeby test Network could send me some funds, I whole-heartedly ...
0
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1answer
19 views

CompilerError: Stack too deep, try removing local variables. How to solve the problem? [duplicate]

I'm having problems with this part of the code. Can you tell me how to solve this problem? I have read various documentation, but maybe someone knows the solution function _getValues(uint256 tAmount)...
1
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1answer
21 views

Solidity | Brownie: Multiple winner lottery not working

Github repo located here: https://github.com/supsam89/digiwear_nft_drop The command I'm having problems with is brownie run scripts/deploy.py I am trying to deploy a drop/lottery contract that picks ...
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0answers
24 views

Storage systems for massive quantities of data

I'm creating a decentralized social media protocol and have begun trying to figure out the right data storage scheme. It feels like storing directly on chain would prove costly, inefficient, and ...
0
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1answer
28 views

How can I send my NFT (ERC721) Token (minted on ContractA) to another Smartcontract (ContractB) so that it is allowed to transfer it?

I try to send my NFT token#300, which is an ERC721 token, minted on ContractA, to antoher ContractB, so that ContractB is now the owner of this Token#300 - so that the ContractB is now allowed to ...
1
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0answers
16 views

How to implement sine and cosine in Solidity?

I want to implement this formula I need a library to implement this. Thanks
1
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1answer
14 views

Multiply number with Pi in solidity

I'm finding a library to implement this formula in solidity. Is there is a library to implement this formula.
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0answers
8 views

Question about Solidity libraries

I hope you are all well. Do you know if it is possible to access a library which is not on the blockchain from a smart contract which is on the blockchain? Thank you Take care Pierre
0
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1answer
12 views

Private network desync

This is a similar to question to this one I have just setup 2 private nodes on AWS EC2 via geth, which are connected to each other, and have 1 "Hello World" smart contract already mined. ...
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1answer
12 views

How to save truffle artifact for already deployed contract?

I have several contrats to deploy on different chains. Normally, when I just deploy the contract with truffle-v5 it creates/updates json object of artifacts by the path ./build/contracts/MyContract....
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0answers
15 views

Rinkeby testnet with Opensea metadata not showing

I deployed en ERC721 smart contract to Rinkeby testnet, where I was able to see the collection i minted for myself in the constructor (with images + metadata). Now, when I minted from a different ...
0
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1answer
21 views

Gas is too high in contract

I have the following stake function that whenever I call it uses almost 100.000 gas. I did the usual stuff optimizing the code to use less gas like using structs and uint256, but the gas price is ...
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0answers
11 views

About rinkeby faucet [duplicate]

It has been more than 24 hours since faucet did not send any ETH. I am also checking other addresses and cannot find transactions from faucet. Does anyone have information? Also can I have some ETH ...
0
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2answers
10 views

Is it possible to check the Connected RPC network in MetaMask using JQuery?

In my DApp, I want to check whether the MetaMask in connected to BSC Minnet RPC network using JQuery. Is it possible to check the Connected RPC network in MetaMask using JQuery? Thanks a bunch in ...
0
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0answers
7 views

quroum web3 send value to contract with metamask

I am trying to send value to contract but whatever I type in value doesnt effect the metamask prompt still displays 0 eth. code as follows: let contract = new web3.eth.Contract((await getABI()).raw, ...
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0answers
11 views

New blocks delay in my full node

I am subscribed to the new blocks on my node: newHeads Fires a notification each time a new header is appended to the chain, including chain reorganizations I have a node that exceeds two on the ...
1
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0answers
11 views

Nodes running in archive mode cosumes different disk space?

I have 2 nodes, running in archive mode, both using Geth/v1.1.2-c4f93121-20210825/linux-amd64/go1.15.14. Both of them has finished syncing with the network (I checked using eth.syncing and it ...
0
votes
1answer
14 views

What is this function do internally of Time Lock Controller of Solidity?

function hashOperation( address target, uint256 value, bytes calldata data, bytes32 predecessor, bytes32 salt ) public pure virtual returns (bytes32 hash) { return keccak256(...
0
votes
1answer
17 views

How much extra gas does a single storage constant add to a contract?

I am considering adding a storage var to my Solidity contract that would represent the "version" that that contract has. However, I am not sure that the added gas cost warrants that. How ...
0
votes
1answer
21 views

List of tokens available to trade via Ox API (Avalanche)

I'm trying to trade TEDDY on Avalanche via 0x, when I call the tokens API curl -X 'GET' 'https://avalanche.api.0x.org/swap/v1/tokens' -H 'accept: application/json' I only get AVAX, WAVAX, and WETH, ...
0
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1answer
28 views

I sent tokens to the token contract

I transfered tokens with Ethereum chain to the token address and I can't get it back. It will be possible to recover them when ERC223 is implemented? Thank you
2
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0answers
56 views
+50

How to verify signature on server backend with web3j?

I am sending an EIP_712 signature from metamask to the java backend (web3j) and I need to verify it on backend java application. In this topics it is discussed the support of EIP-712 in java (web3j): ...
1
vote
1answer
13 views

web3j cant connect to localhost or bsc network

Issue_title how to connect bsc test network and localhost:8545 Issue_description here is my load contract code PerformanceToken contract = PerformanceToken.load( this.contractAddress, ...
0
votes
1answer
11 views

I am studying the formal verification of smart contracts. What open source projects are worth learning [closed]

Please provide items that have been under maintenance recently
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0answers
17 views

How to do log rotation? [closed]

I find this PR https://github.com/ethereumproject/go-ethereum/pull/426 but it's in the previous repo. I don't see any options allow me to do log rotate from here https://geth.ethereum.org/docs/...
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0answers
11 views

Web3 Does contract call on pending block actually does something?

I have created a simple contract to increment a number and a .js script to call the contract. I run the .js script then I submit the incrementNumber function with remix IDE. I'm using the pending ...
0
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0answers
12 views

How can I set reflections tax fee at 0.25 [duplicate]

As you can't float in solidity how can I set reflection tax fee in decimals. Uint256 public taxfee = (any integer value) 👈 how can I set this fee in float for example taxfee = 0.50
1
vote
1answer
30 views

Can I send ETH to an Smart Contract address?

I'm developing an Smart Contract based in the Openzeppelin's Crowdsale one. When I test the Crowdsale Smart Contract manually, sending ETH with metamask, the SC returns me the correct amount of tokens....
0
votes
1answer
22 views

Can I store a "truly private" variable with EIP712?

I've come across EIP712 utilities in open zepplin. I also found a contract using a draft version here. I've modified their contract to something more akin to what I want to do. I was curious about ...
0
votes
1answer
21 views

Does using SafeMath for uint is herited from child contract

I have this code: contract A { using SafeMath for uint; ... } contract B is A { ... } Does my contract B herits from "using SafeMath for uint;"?
1
vote
1answer
26 views
+50

Trust wallet /wallet connect send transaction with thorchain/bsc/binance or someothe chain

I have a working example how to allow user to transfer eth, how to let him transfer bsc, or thorchain or someother network? This is how I Connect wallet import WalletConnect from "@walletconnect/...
0
votes
1answer
28 views

MIgrate a NFT to IPFS after minting?

Hi I would like to know if it is possible to migrate my NFT from a standard webserver to IPFS after minting it? I already generated and minted my NFTs and now I would like to call the basetokeURI and ...
0
votes
1answer
22 views

Check for interface superset

I want to see if a contract supports an interface that is a superset of a current interface. In specific, I want make sure that any arbitray contract supports "SafeTransferFrom(address,address,...
1
vote
1answer
32 views

Can you get sued as a Smart Contract Developer? [closed]

I recently started work as a Smart Contract Developer. As a developer, can you get sued if the smart contract you deployed gets exploited and people lose alot of money? I think many of us work in ...
0
votes
1answer
30 views

How to send transactions Infura + Web3.js + WalletConnectProvider

I want to initiate transactions using the following stack. However, Infura doesn't support web3.eth.sendTransaction(tx) because it requires the server to hold private keys. Here is a link to how it ...
0
votes
1answer
13 views

Contract Address not valid [closed]

I'm new on the blockchain, I've tried to Verify Address Ownership and the answer was " Please provide a valid Contract Address". I don't know where is the problem and where to start. ...
0
votes
0answers
39 views

Ronin wallets being compromised

I want to format or configure my ronin wallet in a way that if any ETH comes into the address, it will automatically be sent to another address. I have the feeling that my private key is being ...
0
votes
0answers
14 views

Cannot get Rinkeby faucet sending me ETH [duplicate]

Could any of you guys send me 1 ETH to my address ? Rinkeby faucet is a piece of sh... It is even more difficult to get 1 ETH then coding a smart contract. Thank you ...
0
votes
0answers
20 views

Doesn't token metadata used in NFT digital art negate the whole blockchain idea?

I'm new to blockchain/Etherium/NFTs, and I was shocked to learn how NFT tokens that represent digital art are actually implemented. Instead of the blockchain enforcing the integrity of the image data ...
0
votes
0answers
8 views

how to interrogate BigNumber words? [duplicate]

// SPDX-License-Identifier: MIT pragma solidity ^0.8.0; import "@openzeppelin/contracts/token/ERC721/extensions/ERC721URIStorage.sol"; import "@openzeppelin/contracts/utils/Counters....
0
votes
0answers
12 views

Import existing code in Solidity, does it affect contract gas price?

I understand that import your own code in smart contract effect it's gas price (you can find more here: Import in Solidity.. Does it affect the Gas?) But what about already existing code? Let's say I'...
0
votes
1answer
14 views

buy function is not working please help

transact to FpsCrowdsale.buyTokens errored: VM error: revert. revert The transaction has been reverted to the initial state. Note: The called function should be payable if you send value and the value ...

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