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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
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0answers
8 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
13 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
18 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
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1answer
20 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, ...
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0answers
16 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
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1answer
30 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
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2answers
88 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
24 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 ...
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0answers
20 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
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1answer
16 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 ...
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0answers
17 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 ...
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0answers
15 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 ...
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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
16 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 ...
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0answers
14 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: ...
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0answers
15 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 ...
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2answers
16 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
0
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1answer
19 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
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0answers
24 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?
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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 ...
0
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0answers
9 views

Failed to decode output: Error: data out-of-bounds (length=0, offset=32, code=BUFFER_OVERRUN, version=abi/5.0.7)

When I try to call some of the unset getters through Proxy, I get this error in Remix Failed to decode output: Error: data out-of-bounds (length=0, offset=32, code=BUFFER_OVERRUN, version=abi/5.0.7) ...
0
votes
0answers
8 views

Serialized abi was altered during trasmission from Nodejs server

Here is the a text file when it is console out on Nodejs (12.16) server: forsale abi : [ { "inputs": [ { &...
0
votes
1answer
11 views

Override inherited function visability

I have a contract that looks like this: pragma solidity ^0.6.0; import "@openzeppelin/contracts/token/ERC20/ERC20.sol"; contract SwappableToken is ERC20 { constructor(string memory name, ...
0
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0answers
8 views

add erc 721 to contract [closed]

hey I wanna implement an ERC 721 //SPDX-License-Identifier: MIT pragma solidity >=0.6.0 <0.8.1; import "./erc721.sol"; contract TechInsurance is TechInsurance, erc721 { /** ...
0
votes
1answer
15 views

Error when deploying contract to Mainnet but not Testnet

I built and have tested a contract on the Ropsten testnet but when I tried to deploy to the mainnet the transaction was reverted. not sure what the reasoning was I tried not spending all that much to ...
1
vote
1answer
26 views

Zora doesn't allow NFT 1 of 1 editions?

Zora is decentralized marketplace for NFTs that doesn't take any fees from sales of NFTs, built on the Ethereum blockchain. Zora's help docs says Instead of creating artificial scarcity by selling ...
2
votes
1answer
49 views

How to make Solidity Contracts Upgradable with a mapping and state variables?

While making a contract upgradable, I am facing issues with the approach where we split up the code implementation and storage. As of this approach, I have created storage slots for every state ...
0
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0answers
18 views

Solidity compiler,error:not found browser IERC20.sol

Who can halp me with error and codig fleshloan? I try use for my contract http://remix.etherium.org and i have a promlem with compiller,i use code from official docs aave https://www.docs.aave.com/...
1
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2answers
41 views

Metamask not connecting to ganache localhost

I am running a local ganache-cli and my metamask in my browser just keeps saying: Oops! Something went wrong. Here are the network details: name: Localhost RPC URL: http://localhost:8545 Chain ID: ...
1
vote
1answer
14 views

Stale blocks on Ethereum

from https://blog.ethereum.org/2014/07/11/toward-a-12-second-block-time/ At a block time of 600 seconds, as in Bitcoin, this is not an issue; 12 seconds is a very small amount of time, and Decker and ...
0
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0answers
16 views

Return 19% of every transver [closed]

I want to creat a token for my fishing team. The problem is I want to have from any transaction how gets 19% in a another wallet. It is maybe? Sry for my very bad English.
0
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0answers
17 views

Can't buy ETH via Wyre because I can't find the 6 digit code anywhere in my debit card. Why? [closed]

I'm not able to buy ETH via MetaMask (Wyre) because when it asks me the 6 digit bank code to confirm the transaction I can't find it in my debit card. Simply I can't find any pending transactions. ...
1
vote
1answer
87 views

Is ethereum's protocol made in Go?

I came across a repo on github https://github.com/ethereum/go-ethereum . Is this ethereum's official implementation? I mean is it official protocol?
1
vote
1answer
28 views

Aborting/resuming state snapshots all the time

I get this behaviour after updating to 1.10. Is this normal? - I mean, aborting & resuming "state snapshot generation" all the time. Please feel free to explain in more depth what's ...
0
votes
1answer
22 views

When I run the truffle v command in my powershell and get these results

Truffle v5.2.2 (core: 5.2.2) Solidity v0.5.16 (solc-js) Node v12.19.0 Web3.js v1.2.9 where is that solidity version coming from? I know i install truffle globally sometimes, so does it ship with ...
0
votes
1answer
15 views

Beside the block reward winner who will get most rewards from transaction fees?

We know the only winner will get the block reward. Besides the block reward, we know nodes/node clients get rewards from transaction fees. So do all node clients get the same rewards? or the ones who ...
0
votes
1answer
19 views

Any examples of ERC tokens that pay out recurring dividends?

This post discusses the legal side of issuing digital shares of one's company, but once we get past that mental hurdle and assume the real world is now crypto-friendly, can someone provide a working ...
1
vote
1answer
32 views

Which Ethereum user bought Beeple's “Crossroad” NFT video for $6.6 million?

we know the story of who bought Beeple's "Crossroad" NFT video for $67,000 and re-sold it on the secondary market for $6.6M worth of ETH, but who exactly was the person, or Ethereum username,...
1
vote
1answer
23 views

Without a block explorer API, can I programmatically determine if an address has a contract deployed at it (eg using Web3 or call to a node)?

Given an address, from a web application I'm attempting to determine if there's a contract deployed at the address. There are some ways to do this with etherscan or other block explorer APIs, but I'm ...
2
votes
1answer
24 views

Is there a Blockchain StackOverflow? As in an alternative to stack overflow which is blockchain-based

Is there a Blockchain StackOverflow.com alternative? I'm wondering if there exists some product, which is basically just stackoverflow but a blockchain platform? Something which cannot be controlled ...
1
vote
0answers
19 views

ethers is not defined

In hardhat, I want to access a contract outside my project in my tests. In my hardhat.config.js I am able to reference external contracts no problem with an ABI and a contract address, like so: const ...
1
vote
0answers
5 views

Recalculated downloader QoS values & Current full block not old enough

I'm trying to build the private network between two raspberrry Pi3B with Geth. But when i started the node and entered the javascript console, it keeps showing the following message, and i don't know ...
0
votes
0answers
13 views

MAPPING TO ASSOCIATE ETH ADDRESS [closed]

Write down a smart contract that meets the following requirements. It uses mapping to associate Ethereum address with associated value It uses a function to set the balance with a specific address It ...
0
votes
1answer
14 views

full stack dapp clone example elastic supply algorithmic stablecoin

I'm new to vyper (but have some python experience), I would like to clone a very simple dapp to have a look at the full stack of an ethereum dapp from back end (write compile and deploy a simple ...
0
votes
0answers
12 views

How to approve spending limit on Metamask or Etherscan to complete a swap on Balancer Exchange?

Hope you can help unstick this transaction... I recently used Balancer Exchange to swap USDC for KYL via Metamask. The transaction shows as successful on Etherscan but my Metamask balance has not ...

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