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Creating ERC20 or ERC721 in Optimistic Rollup

If there's a dapp running in optimistic rollup that lets users mint new ERC20 and ERC721 tokens. How can ETH main chain know about the new minted tokens?
2
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0answers
8 views

Got error!!Trying to deploy smart-contracts in ropsten infura

When I am trying to migrate smart contracts in ropsten infura network, but got error. The error is shown below: Using network 'ropsten'. Running migration: 1_initial_migration.js Replacing Migrations....
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0answers
7 views

Cannot call function in openzepplin ERC1155 contract via web3/metamask

I am trying to call the balanceOf function in a pretty barebones openzepplin ERC1155 contract through metamask. I am using web3 only to generate the ABI, and metamask to actually send out the call. ...
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1answer
7 views

Sell my own NFT?

On what platform can I sell my own NFT? I've seen NFT's kick-off recently. I have seen certain more exclusive platforms launch where large sales are being made, but have not seen one where anyone can ...
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0answers
6 views

Problem with block of Solidity code (specifically the ROT-specific token burn code)

Been messing around trying to learn the basics and tried to implement the token burn part of RottenSwap (fork of SushiSwap with ~10 lines of code changed). Basically it burns a % of one coin (ROT) ...
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0answers
4 views

If a block header is 80bytes, then why does a full node need ~100GB of storage

So, I'm a little confused about how data is stored in a block. If You can get the state of all accounts from the State Root of a block header, then that means that you can get the state of every ...
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0answers
7 views

Can't access my ethereum presale wallet

Anyone can help me? I can't access my Eth wallet presale, I already input the password but it always say wrong password.. can anyone help me.. Where I can import my wallet and how to find a password.. ...
1
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1answer
9 views

How to get the actual runtime bytecode from creation bytecode and constructor arguments without deploying

Possible outputs of the Solidity compiler include creation bytecode and deployed (runtime) bytecode. However, this compiled deployed bytecode might not be the same as the one that will actually be ...
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0answers
5 views

Can't make react app

I was trying to make a react file so I could code a cryptocurrency exchange, but I have a problem with my dependency tree and I can't remove the packages 1. Delete package-lock.json (not package....
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0answers
16 views

Is there a blockchain reddit alternative?

Is there a blockchain Reddit alternative? I know of Reddit alternatives like communities.win but it's not blockchain and one cannot create a new community on one's own.
2
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1answer
12 views

In the geth codebase where is the smart contract function executed

I'm looking to add some logging code to Geth. I have a vm created with a single geth node and private blockchain running. I've deployed a smart contract to it. I want to initiate a transaction on ...
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1answer
18 views

Get Uniswap Exchange Rate of any Token with Web3

I need to get the exchange rate for every token on Uniswap with Web3 like Uniswap itself which they then display on their web interface on app.uniswap.org like this: So when I enter to swap the ...
1
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1answer
17 views

Is it gas efficient to store the msg.sender in a local var?

Suppose I have a function that refers to msg.sender many times: function foo() external { doSomething(msg.sender); // ... doSomethingElse(msg.sender) // ... emit LogSomething(msg....
3
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0answers
18 views

how does Ethereum singing request work?

What's the need so that some dapp websites ask you to sign messages via metamask the first time you get on their website ? as I read, it's so that they make sure you get authenticated. So you sign the ...
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0answers
10 views

Connecting external server to Ethereum node via RPC failed “bind: cannot assign requested address”

I am trying to connect an external server to my Ethereum node. Considering I don't want to use --rpcaddr 0.0.0.0 (which it works)for security reasons, I am using the following command to start geth: ...
1
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1answer
19 views

Remix Solidity Smart Contract Stuck On Compiling State

The 1inch Smart Contract is unable to compile in Remix as it appears to be stuck in the Solidity compiling phase. Expected Create a new 1inch_38211317.sol smart contract file in Remix. Compile the ...
2
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1answer
9 views

OAuth/BearerTokens in ChainLink

How to add an authentication header for ChainLink API requests? For example, this guide on connecting ChainLink to Twitter API to post a tweet doesn't implement anything of the sort, so how would it ...
1
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0answers
12 views

Can NFTs be stolen from a web wallet? Is there cold storage for NFTs?

Many NFT collectors move their claimed NFTs (NFTs that they won) from their web wallet (e.g. Metamask) to a different wallet that they call a vault wallet. What is this vault wallet? Is it a hardware ...
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0answers
6 views

Creating Custom Wallet for my ERC20 Token

I am currently working on a project for school, I just finished writing my smart contract. A buddy of mine is going to make a custom wallet for me since it will help for his class project. We are ...
1
vote
1answer
15 views

How to get the return value on a state altering function?

I'm playing around with ERC721 tokens. I have this mint function in my contract that is supposed to return a value, but in my client app (using Web3), the result I get from this function call only ...
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0answers
8 views

Uncaught TypeError: contract.method is undefined

if (typeof web3 !== 'undefined') { // If a web3 instance is already provided by Meta Mask. web3Provider = web3.currentProvider; web3 = new Web3(web3.currentProvider); } else { // Specify default ...
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0answers
8 views

Miners in GETH increases performance?

I am trying to set up my own private network using GETH. I have a limited number of miners right now. Currently, 2 miners are running. I experienced quite slow in performing transactions. I added up ...
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0answers
14 views

Eth command solo mining CMD does not run

Eth command solo mining CMD does not run as expected I have downloaded ethminer-0.19.0-alpha.0-cuda10.0-windows-amd64.zip from https://github.com/ethereum-mining/ethminer/releases ethminer-0.19.0-...
3
votes
1answer
26 views

How can callable contracts have an empty account state?

On page 4 of the yellow-paper, the definition of an "empty" account is provided. An account is empty when it has no code, zero nonce and zero balance. A formal definition is then provided, ...
2
votes
2answers
431 views

Defi-Staking is it 100% safe?

I was reading on crypto staking, more precisely Defi-Staking on Binance: https://www.binance.com/en/defi-staking While I am not a native english speaker I could understand that there is no risk in ...
0
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1answer
18 views

uniswap transaction issue. unable to locate txnhash

I am trying to exhange one token for the other however the transaction is not going through, on etherscan when i go to view the transaction overview it states "sorry, we are unable to locate this ...
1
vote
1answer
29 views

How do I determine the most recommended (safest to use) version of Solidity?

I've seen this question pop-up a bunch of times: "is version 0.x.x safe to use in production?" Therefore, I'm wondering if there is a clear way to tell which versions are recommended for ...
1
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0answers
24 views

Reusing Ethereum deployed smart contracts

I have developed and deployed my token and stacking contracts on the ethereum main net, now I want to deploy them on the Binance Smart Chain(BSC), my question is Do I need to modify my current written ...
1
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0answers
27 views

Smart contract copying code beyong code length

I've seen a couple smart contracts (eg the contract decompiled in this answer) use this pattern: Code[Code.Length:Code.Length+x] This surprised me because I would expect Code.Length to mark the end of ...
0
votes
1answer
29 views

Is it possible that a smart contract receives ether and if condition is true then send those ether to specific account?

I am planning to create an app that connects to the Binance account of the user (API) and trades automatically with his credentials. If transactions (only one buy and sell pair) successfully earn BTC, ...
0
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0answers
23 views

Internal JSON-RPC error. { “code”: -32000, “message”: “gas required exceeds allowance (30000000) or always failing transaction” }

I'm working on remix and I'm connected to the BSC Testnet. I am trying to make a transaction of ERC20 tokens in an ERC721 contract by calling the ERC20 contract. However when I try to make the ...
2
votes
1answer
35 views

solidity math overflows

function nice(uint8 x) public returns(uint8 z){ uint8 z = 0; z = z + 240; require(z = z + x, "overflow"); } I have been using this code with the solidity versions, ...
2
votes
2answers
101 views

why require() is checked after executing transfer()

From OpenZeppelin's ERC721 contract: function _safeTransfer(address from, address to, uint256 tokenId, bytes memory _data) internal virtual { _transfer(from, to, tokenId); require(...
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0answers
29 views

List of contracts bound to an address

Is it possible the view the list of all contracts an Ethereum address is bound to? scenarios: John deposited funds in many DEXs but can't remember which ones. John would like to see if his wallet has ...
0
votes
1answer
30 views

Unable to deploy smart contract on private blockchain

I'm trying to setup a private blockchain and deploy some contracts to it. I have the blockchain running but I am running into issues when I'm trying to deploy a contract to it. This is my genesis ...
0
votes
1answer
20 views

How to generate a signature with web3py like metamask does?

Most ethereum apps request signatures like this How exactly do i recreate this signature in web3 py? Is there any way i can view the data that gets sent thru metamask? I have tried the following code ...
0
votes
0answers
21 views

Json RPC eth_sendTransaction data parameter

I have a question concerning the data parameter of the json RPC method eth_sendTransaction. Is it possible to send any kind of data structure with this method to a smart contract? Is it possible to ...
0
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0answers
18 views

TypeError: Member “checkAirlineRegistered” not found or not visible after argument-dependent lookup

So I made database and app logic smart contracts. App logic smart contracts will call functions in database smart contract. One of the functions acts as a way to check the data that has been put in ...
0
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0answers
18 views

Why ETH Transfer from Nethereum taking longer time then transfering from metamask wallet?

I am sorry for nubby question. Today i made a ETH transfer of 0.00001 ETH 2 times. One programmatically with Netherium SDK and another directly through metamask wallet to another metamask wallet. Here ...
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0answers
17 views

Error parsing openzeppelin. Expected pragma, import directive or contract/interface/library definition

None of the solutions that I saw solved this issue. When I do truffle compile I get this error Error parsing @openzeppelin/contracts/GSN/Context.sol: ParsedContract.sol:15:1: ParserError: Expected ...
0
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0answers
22 views

org.web3j.protocol.exceptions.ClientConnectionException: Invalid response received: okhttp3.internal.http.RealResponseBody

Environment Android Studio Infura – Rinkeby test network Web3J Metamask Rinkeby.etherscan.io I am trying to build an Android app to read and write smart contract by following the medium article: ...
1
vote
0answers
16 views

Interaction between 2 nodes of ganache

I am making a project on blockchain where in I am using ganache for private blockchain, meta mask to interact with the same. Since ganache provides 10 nodes in the private blockchain, I want all the ...
0
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2answers
17 views

remix “no contract compiled yet” although contract is error free

Im trying to run code on remix. But it's showing "no contract compiled yet" although contract is error free My contract- pragma solidity ^0.8.0; contract Dwitter { //state variables ...
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0answers
10 views

ESOCKETTIMEDOUT ERROR while trying to deploy to Rinkeby

Unable to deploy a simple smart contract to Rinkeby
1
vote
1answer
21 views

“Add Token” in Metamask

Why is it necessary to manually add a token you will transact in (before the actual transaction) in Metamask? What happens if someone doesn't do that before a transaction, to display that balance in ...
0
votes
0answers
28 views

maintaing metadata while ERC721 cross-chain transfer

I want to make any ERC721 token (on any contract) to be transferable from ethereum to MATIC chain (fully compatible with EVM with deployed support contracts on ethereum). So I am doing the following ...
0
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0answers
7 views

Retrieved Uniswap token price from smart contract is inaccurate compared to the one displayed on Uniswap interface

I'm trying to create a bot using JavaScript that interacts with Uniswap's smart contracts. I have been using UniswapV1's factory and exchange contracts, and I was using the getEthToTokenInputPrice ...
1
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0answers
8 views

Calling smart contract on private Geth network using Esp32/arduino

I'm trying to call smart contract deployed on private geth blockchain. I couldn't find relevant library on ESP32/Arduino to interact with smart contract. What should I do?
0
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0answers
21 views

How do I manipulate data in multiple contracts and output them

I am trying to manipulate data I retrieve from my contract, and then display it. Currently, I am running into 2 problems: 1- I am unable to manipulate the data correctly. 2- I am unable to display ...
0
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0answers
6 views

Transfer token sent to wrong address (contract address)

Good day/eve. I purchased the OMI token and initiated a withdrawal to my trezor hardware wallet as an ERC20 token. This was an error (isn't an ERC20 token any longer) and therefore the transaction ...

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