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TransactionException: Cannot unmarshal invalid hex string when deploying contract in web3j

I have a java server that uses web3j library with geth as the provider. When I tried to deploy my contract on my private test net. I got this error: org.web3j.protocol.exceptions.TransactionException: ...
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0answers
3 views

Issue with go-ethereum on freebsd

I got an issue when I am trying to run a sample test code via go to access my full node. Consider the following code snippet: package main import ( "context" "fmt" "log" ...
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0answers
13 views

Chainlink - on-chain contract functioning

The on-chain aggregation smart contract for ETH/USD on the mainnet (https://data.chain.link/eth-usd) is at this address https://etherscan.io/address/0x5f4eC3Df9cbd43714FE2740f5E3616155c5b8419#code. If ...
1
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0answers
9 views

Cannot verify Contract - bytecode has small difference

I forgot to verify the ERC20 token contract after deploying it. Now after 5 months, Im doing it again and completely forget which compiler and if I accidently change anything on the code. After ...
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1answer
11 views

ERC721 testing transferFrom()

How can I test (truffle test or development console) the following: await nft.transferFrom(accounts[0], accounts[1], 1); await nft.transferFrom(accounts[1], accounts[0],1); The second line throws ...
1
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1answer
14 views

How many new nodes join the Ethereum Network per month? How many leave?

I'm researching the cost of serving old blocks to new nodes that need to synchronize and download the whole blockchain. I can indirectly estimate the bandwidth consumed to serve old blocks, if I know ...
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0answers
16 views

Transfer Failing in Solidity Smart Contract

I am calling the following function from a front-end on a Solidity smart contract, but it is not transferring the price and commission amounts properly with the call functions, although the ownership ...
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0answers
8 views

Connecting a geth node over LAN to a public geth node on my network

I need to run 2 geth nodes on separate computers on my network (ethereum Mainnet). I understand that I could connect them both to public peers the regular way over the internet simply by changing the ...
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0answers
8 views

I got an error installing Node GYP

I'm just about to work on a very big project, but I need this tool and it won't install npm ERR! code EACCES npm ERR! syscall rename npm ERR! path /usr/local/lib/node_modules/npm npm ERR! dest /usr/...
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0answers
8 views

Retrieve deposited number of Uniswap LP tokens from smart contract

I’m doing yield farming on a smart contract and I try to find out the total amount of my deposits. I know that I can follow the ERC20 tx on etherscan, but I would like to find an easier way. Under ...
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10 views

I can't call my functions in the components which I can improve to make web3 work correctly?

I'm having a problem with components, I'm using truffle unbox / react, I created a BuyForm.js component that will be the purchase form but I have problems trying to make the purchase I'm not able to ...
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1answer
9 views

Dual mining ETH/ZIL with 4GB?

I recently saw this video about dual mining of ETH and ZIL. The video especially targets GPUs with 3-4GB of VRAM. I still have to try it, but I'm wondering: isn't ETH dagger size bigger than 4GB? How ...
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10 views

Unblockable P2P Network possible?

P2P peer discovery has few methods which are multicast DNS on the local network, trackers, distributed hash tables, and etc. But all these methods require first connection to a constant peer that ...
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0answers
8 views

Received DeclarationError when calling other contracts file name and its function

So I created 2 contracts where the first one will be the app logic contract and the other one is the database contract. So I tried to "truffle compile" my contract but receive ...
-2
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0answers
19 views

What's the best place to hire Eth dev? [closed]

What's the best place to hire Eth dev?
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0answers
9 views

Generate Ethereum account in a JSON/UTC v3

What are some trustful ways to generate an Ethereum account in a JSON/UTC v3 format? I know some web wallets, but I would prefer a very used/well-known desktop or plugin wallet. Metamask does not ...
1
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0answers
11 views

Running ERC20 contract on RSK

I have been reading about RSK lately and was wondering about the compatibility and possibilities, so I wanted to ask for some basic info in case there's someone more knowleadgable. I have a smart ...
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0answers
8 views

Where is OR using contract deployed?

Just trying to understand a bit about Optimistic Rollups. Was wondering where does the actual contract that uses ORs gets deployed? Is there a copy on both L1 and L2? I would assume yes, since how ...
0
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1answer
14 views

Etherscan Input bool is 1 or true or True

I want to execute a smart contract function that takes input bool. Here for example makes the distinction that web3 uses javascript which doesn't consider 1 as true, but solidity does consider 1 as ...
1
vote
1answer
27 views

Get total supply of any ERC20 token in Solidity

I'm a new developper on Solidity and maybe this is a trivial question but it is a crucial point for my project. Is there any way to get the total supply of any ERC20 token (WBTC, and others) on ...
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0answers
20 views

How do I pick up Ether after Crowdsale? And other questions

Testnet: Rinkeby Address token: 0xeAD7ACF95b260E4C866a036F9E792759Ba0Ad4ce Address Crowdsale:0xf2D4B282CE60A0abBE7fb74C694A9A04087E5519 Ethers credited at the end of Crowdsale: ...
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0answers
5 views

Geth/Parity node - When is a new block imported

Based on my observations and also on block-timestamps-vs-received-timestamp, I suppose that a block "n" is imported into geth or parity node, only after a block "n+1" is mined. Is ...
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0answers
15 views

Challenge: What is Ethereum's 1 Billionth transaction?

I am trying to find ethereum's 1 billionth tx for a project but I don't know how I would go about finding this? Also if you already know what the tx is would be great if you could share! Thanks
0
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1answer
12 views

How to use Oraclize (Provable Things) in smart contractin Remix ide ? i have a program of exchanging Ethereum to USD [closed]

`pragma solidity > 0.7.0; import "github.com/oraclize/ethereum-api/provableAPI.sol"; contract USDPrice is usingProvable { uint public price; event Log(string text); function USDPrice(...
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0answers
12 views

“No Contracts Deployed” TRUFFLE ERROR PLEASE HELP!

I really need help! [12:20 PM] i deployed an erc721 smart contract to testnet, it worked fine! Then i deployed it into the live network. It worked. But, i have an other script to mint my tokens. I ...
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0answers
17 views

How do I execute this Timelock contract on Remix Ethereum?

i am using a timelock smart contract but im not sure how to input the proper value to use this function on remix. what exactly do i put in data byte field? how do i get that data from the other ...
1
vote
1answer
18 views

What are the available options (March 2021) for bridging tokens across the chains?

Actual problem in mind I would like to release a token for the Island DAO. I'm worried that ETH gas prices are prohibitively expensive - if I use ETH, the smaller guys will not come. But ETH is the ...
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0answers
13 views

Division and floor rounding with 18 decimals

I am recreating a UNISWAP-like AMM and have encountered problems anytime I want to divide the balances of tokens in my pool. For example: I want to require() that tokens are deposited in the correct ...
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0answers
9 views

How to add Lock Function on solidity?

I have code for the ERC20 token which has freeze, unfreeze, lockUser & unlockUser functions. I want: When I lock someone he will be automatically unlocked after x days or, Scheduled release of ...
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0answers
14 views

Truffle Mainnet - “No contracts deployed.”

I really need help! I created an ERC721 smart contract and deployed into the rinkeby test network. All was nice, after that I deployed into mainnet. I set the gas price to 65 Gwei. Now the contract is ...
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0answers
13 views

Why must gas limit be set to 900 more than actual gas usage?

I have a contract which a specific function call will always cost x gas. However, setting the gas limit of the transaction to anything less than x + 900 will result in an out of gas error. What is ...
2
votes
1answer
11 views

Cancelled Transaction in MetaMask USDC leads to loss of funds

I had attempted to transfer 992 USDC from MetaMask to a Ledger Account but had decided to cancel the transaction. On cancelling, MetaMask reports that the cancellation succeeded, but my MetaMask USDC ...
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0answers
7 views

Is there any way to browse DeFi apps with “watch-only address” wallet?

I like to sign my transactions with a offline computer, then broadcast on the network with an online computer. This way I never get hacked. With MEW, it is possible to send ETH to another address like ...
0
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1answer
14 views

The called function should be payable if you send value and the value you send should be less than your current balance. WITH NON-Payable functions

I have the following functions function balance() public view returns(uint152) { return uint152(IERC20(token).balanceOf(address(this))); } function balance1() public view returns(...
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0answers
19 views

Cannot find module '@truffle/db'

I am following a tutorial to build smart contract. And when I do the truffle migrate, there is en error shows can not find module truffle/db
0
votes
1answer
20 views

Does revert() send received ether back to sender?

When revert() undoes all state changes, does that include sending any received ether back to the sender? For example, would both sendBackOne() and sendBackTwo() send ether back to the sender? function ...
0
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0answers
14 views

GSN Contract but only for one function

I'm blindly trying to implement OpenGSN in my contracts. I'm still not sure how it works. Do I need a special application running and scanning for signed messages on my computer to make it working? I ...
0
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0answers
10 views

Is it possible to install 2 geth ethereum nodes with one external ip?

I want to install 2 nodes in one local network, will I succeed? and what is needed for this?
1
vote
1answer
15 views

How to extract the URL of a crypto art as it appears within the NFT? and technical details like ERC-token type?

The following piece of crypto art has a title, description, and additional details regarding file and image size, provided by the NFT platform (Makersplace) where the artist (Lumi) minted the NFT for ...
0
votes
1answer
23 views

If crypto art is stored off-chain, how does the collector have any control over their NFT's contents if the server where it is saved shuts down?

CryptoKitties essentially sells crypto art NFTs to collectors on the Ethereum blockchain. However, the pictures of the cryptokitties are stored on the company's server, since the NFT merely represents ...
1
vote
1answer
19 views

How to recognize if a website is a DApp?

A Launch App button often appears on the top-right corner of Ethereum-platform websites. Is this an indication that a link is a link to a DApp (decentralized application)? Are the following two ...
0
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0answers
14 views

From what source does etherscan.io aggregate and broadcast data that appears on the blockchain ledger?

as blocks are hashed together as transactions pile up and are broadcasted on the Ethereum blockchain, how exactly does the website etherscan.io in turn publish and broadcast all that information in ...
0
votes
1answer
12 views

Can't use Uniswap contract function 'swapExactTokensForETH'

When using Uniswap function swapExactTokensForETH() I get the following error: 'TransferHelper: ETH_TRANSFER_FAILED' Contract code: pragma solidity 0.8.0; import "https://github.com/Uniswap/...
0
votes
0answers
6 views

web3.py - AttributeError: 'Eth' object has no attribute 'get_block'

So... I'm probably being super dumb - but I started using web3.py in a jupyter notebook and it connects to the node just fine... but I can't seem to use any .eth methods as it throws a: AttributeError:...
0
votes
1answer
19 views

How to validate a transaction from any block in Blockchain

Given that we have a Blockchain with smart contracts. We have end users operating the platform for some time. Now one user wants to verify the claim of a transaction. Example, I have to prove that ...
0
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0answers
8 views

im looking for an exchange to trade my tokens cheap

0 Is there any other site i can send my tokens to, where i can trade them for like a normal rate like on binance? trying to trade 50$ worth of token but the gas fees are 80$ - to 140$ how does that ...
0
votes
0answers
9 views

Is ownership of tokenized real assets through NFT upheld by law?

Let's say you've tokenized your house as a non-fungible token (NFT) on the Ethereum blockchain. if an NFT simply represents ownership of a tokenized asset, what actors or agencies currently will ...
2
votes
2answers
28 views

What tokenized assets can be stored on-chain?

Examples of digital assets that can be tokenized as NFTs are: crypto art (.jpg or .png file stored off-chain) game weapons or characters Examples of physical assets that can be tokenized as NFTs are:...
1
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0answers
13 views

My contract shows a zero balance on Metamask

I just need some help on a contract I'm doing an experimental project token for. My setup as follows: Using Remix for solidity Metamask account linked Contract is using pragma ^0.4.4 (original code ...
0
votes
0answers
5 views

Truffle not working after install using npm

I just tried to install truffle using npm. I followed the documentation and did npm -g install truffle However, after that, when I try to do anything (such as just run truffle or truffle --version), I ...

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