Questions tagged [kovan]

Kovan is a new testnet for Ethereum using Parity's Proof of Authority consensus engine, which is immune to spam attacks as Ether supply is controlled by trusted parties and provides a consistent 4 second block time.

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0 votes
1 answer
274 views

Howto check sync with kovan testnet is complete or not?

I am trying to sync with Kovan testnet, docker run --name eth -p 8546:8546 -v ~/ws-002-chainlink/ws00-docker-geth-ropsten:/geth -it ethereum/client-go:stable --testnet --syncmode light --ws --wsaddr 0....
7 votes
1 answer
773 views

Parity Error: Account not found for the current chain (Kovan)

I am having problem starting Parity with a account that I created using Metamask. This account 0x76Eb17471A5fb78EF6768254D1dAEc528ec6b5a8 has received multiple ETH from Kovan faucets. Running the ...
0 votes
4 answers
283 views

Error: Private key does not satisfy the curve requirements (ie. it is invalid)

I have a project working fine on truffle but when migrating to Kovan network, Getting the issue "Error: Private key does not satisfy the curve requirements (ie. it is invalid)" project is an ...
0 votes
2 answers
656 views

What is this STF error when trying to use a function in a contract

I know there are many similiar questions but i can not figure out how to implement the 'approve' part in. pragma solidity ^0.8; pragma abicoder v2; import '@uniswap/v3-periphery/contracts/libraries/...
2 votes
2 answers
475 views

How to connect these **Remix - kovan - parity**?

I have been trying to connect deploy a smart contract from remix onto kovan chain via parity but kept on showing even after trying with all the rpc flags. if possible please throughly explain the ...
1 vote
2 answers
373 views

How to get failed transaction status code by using python web3?

Given transaction hash, i want to fetch Status code ('45' in this case, refer below image) with which transaction has failed using python web3.py. I already tried these methods, they don't seem to ...
1 vote
1 answer
48 views

Function to store the strings from an api in an array and print the strings I want

I have this smart contract: *//SPDX-License-Identifier: MIT pragma solidity ^0.8.7; import '@chainlink/contracts/src/v0.8/ChainlinkClient.sol'; import '@chainlink/contracts/src/v0.8/ConfirmedOwner.sol'...
3 votes
1 answer
576 views

Contract transaction couldn't be found after 50 blocks in Kovan

When deploying contracts on the ledger I faced with issue Error encountered, bailing. Network state unknown. Review successful transactions manually. Error: Contract transaction couldn't be ...
0 votes
0 answers
53 views

Fail with error 'SafeMath: subtraction overflow'

I am trying to use the "create" function from an LSP smart contract from the UMA protocol but I can not use it it always returns the "Fail with error 'SafeMath: subtraction overflow'&...
10 votes
5 answers
30k views

Where can I find test-ether for the Kovan Test Network?

I have tried getting some using my github account but my account got flagged immediately and the program wasn't recognizing my account (Since it wasn't public due to being flagged). Are there any ...
0 votes
1 answer
364 views

Transaction not showing on Kovan etherscan even after its status showed transaction mined and executed successfully

I have my contract deployed on Kovan Testnet and from remix IDE I called one of the functions of my smart contract through remix itself. Now, the status of transaction shows "transaction mined ...
3 votes
4 answers
952 views

I keep getting nonce is too low when using truffle to call functions on contracts even though this works fine on remix.How can I fix this

I keep getting the nonce is too low when running functions with sub transactions on the kovan test net is there a way I can stop this from happening?these sub transactions are making transactions with ...
0 votes
2 answers
1k views

Cannot obtain Kovan testnet Ether

Does anyone else have issues obtaining kovan ether? I have tried the following links only to recieve 0.01 Keth increments from app.mycrypto.com (when the site is up). The github sites do not respond ...
0 votes
2 answers
23 views

initial transaction reverted, but cannot rebroadcast due to error: Transaction with the same hash was already imported

I'm trying to deploy my project to Kovan and the initial deployment tx reverted, but any attempt to deploy again is stopped by this error. Shouldn't the fact that my initial tx failed remove it from ...
1 vote
1 answer
643 views

Connect local React frontend to contract on testnet (e.g Kovan)

I am new to this community and I had a question, in my opinion I think basic, but I have not found much information, see if you can help me. I have been developing smart contracts, both in Remix and ...
1 vote
1 answer
445 views

How to verify my account in order to use the Kovan testnet?

I am new to parity and kovan-testnet. I have to verify my account in order to receive keth. I am confused as to where to execute the following code: curl http://github-faucet.kovan.network/url --...
1 vote
2 answers
227 views

OpenZeppelin contract not working on Kovan testnet

I created a simple smart contract using OpenZeppelin and deployed the contract to the Kovan testnet. However, when I send KEth to the contract using MetaMask, nothing happens (I believe the buyTokens ...
0 votes
0 answers
15 views

Question about finding token addresses to insert into a .sol Contract function

Ok so I have a .sol Contract that is trying to find arb between 2 dexes I'm utilizing the Kovan Test Network - this is the function function estimateDualDexTrade(address _router1, address _router2, ...
0 votes
1 answer
202 views

How to get Sushiswap and Uniswap prices from API for WETH/DAI on KOVAN?

Where can I find APIs to query data of WETH/DAI Prices on Uniswap and Sushiswap? For the mainnet, there is thegraph.com where one can query price data with pre-defined GraphQL queries, but I can't ...
0 votes
0 answers
9 views

Signed transaction reverts Kovan

I am trying to send signed transactions against a smart contract in the Kovan network. I can send transactions which do not change the state of the EVM and they work fine but I can not get ...
0 votes
0 answers
38 views

Gas estimation reverts

I am quite new to blockchain programming and am trying to estimate the gas cost of calling a function from a smart contract. I am using Web3 js and the Kovan network through an Infura node. What am I ...
0 votes
0 answers
49 views

Get the connected accounts to a specific network from Metamask using web3.js

I am creating a dApp on Kovan Testnet. Can anyone tell me how can I get the connected accounts to Kovan from metamask using web3.js? I can get the accounts added to the Metamask using this, const ...
1 vote
1 answer
233 views

List of Token Exchanges Available on Testing Network?

Found Kyber Network Token Exchange on Ropsten so far. Please share if you know more token exchanges available on any testing network for trading Tokens as a test.
137 votes
2 answers
61k views

Comparison of the different TestNets

The Metamask wallet allows access to four test networks: Ropsten Kovan Rinkeby Goerli I'm curious: What are the similarities/differences between them? Which use cases are best for each network Are ...
1 vote
1 answer
290 views

Troubles interacting with Chainlink node on Kovan

I've been following instructions on running a local Chainlink node on Kovan. My environment is configured to Kovan through websockets via Infura and the node is both running and successfully accepts ...
0 votes
0 answers
249 views

How to get detailed error for ValueError: {'code': -32016, 'data': 'Reverted', 'message': 'The execution failed due to an exception.'}

I deployed my Fund_me smart contract on Kovan testnet and I tried to call the withdraw function on it using web3, but I'm getting the error ValueError: {'code': -32016, 'data': 'Reverted', 'message': '...
1 vote
1 answer
123 views

How can I call a deployed smart contract on Kovan using Python?

The smart contract was written and deployed on Kovan using Remix IDE and injected Metamask Kovan test network account. However, I'll need python to deal with large input of a function in the smart ...
0 votes
1 answer
45 views

contract has not been deployed to detected network (network/artifact mismatch) when use truffle console --network kovan

i'm trying to call a function from contract that i deployed to kovan network, then when i used the truffle console --network kovan and tried to deploy my contract, it says that this contract has not ...
0 votes
1 answer
94 views

Kovan Test Net: not receiving test LINK

I tried to receive Link on the Kovan testnet two different ways, with the same result- No error message, it just continues to load endlessly. https://kovan.chain.link/. a) "Send me 100 test link&...
0 votes
1 answer
346 views

Can't get Kovan testnet from Faucets.chain.link

I'm trying to get the ETH -> USD price from ChainLink but it's code requires the Kaven testnet. But the problem is that the https://faucets.chain.link website isn't working correctly and it sends ...
1 vote
2 answers
1k views

How to connect from Remix to Kovan testnet?

In Remix, there is a Contracts tab, where I can choose the "Execution environment". When I choose "Web3 Provider", I am asked to provide the "Web3 provider endpoint". What should I write there in ...
1 vote
2 answers
224 views

Error: This contract may be abstract, not implement an abstract parent's methods completely, not invoke an inherited contract's constructor correctly

Injected web3 Kovan 42 network Remix IDE This is from the freecodecamp.org tutorial on youtube Here is the code : // SPDX-License-Identifier: MIT pragma solidity ^0.8.7; import "@chainlink/...
0 votes
0 answers
134 views

problems deploying a contract on the Kovan network

Good evening, a couple of days ago I was able to execute this command without any problem and today, suddenly, I got this error. I don't understand what it means by "insufficient funds". ...
0 votes
0 answers
209 views

How to query Uniswap API to get cryptocurrency pair price on ethereum kovan network returns call revert exception error

I am currently trying to request a currency pair price from two tokens published on Uniswap at: https://app.uniswap.org/#/pool/10341?chain=kovan. Following a tutorial, I managed to successfully ...
0 votes
1 answer
1k views

Can I exchange test kovan eth to main eth? [duplicate]

I have some test eth. But I don't know how to use them. Can transfer as real eth Or what I have to do that please help me. Or I can sold them. In that case at how much cost can I sold.
1 vote
1 answer
4k views

Where to find and how to get Kovan USDC testnet tokens

I need USDC Kovan testnet tokens transffered to this address 0x2E9b971e336C825BC41b9FE87376E74f0B3345FE for testing purposes. Token contract for this token is https://kovan.etherscan.io/token/...
0 votes
3 answers
635 views

Kovan Chainlink Faucet - Unable to locate the transaction hash

Etherscan says "Sorry, We are unable to locate this TxnHash" when sending LINK using both https://kovan.chain.link/ and https://faucets.chain.link/kovan Waiting for a long time already but ...
0 votes
0 answers
204 views

How do I listen to changes for an ethereum address using websockets + RPC eth_subscribe method + postman

I am trying to listen for changes in a wallet balance on the Kovan testnet , so I have connected to a Kovan node using a node provider's websocket endpoint, I have no errors connecting, and no errors ...
2 votes
4 answers
2k views

truffle migrate --network kovan issue

When I run truffle migrate --network kovan in the terminal the contract deployment doesn't run. Just: Compiling your contracts...==================== >Eveything is up to date, there is nothing to ...
9 votes
3 answers
9k views

Sending multiple transactions in the same block with incremented nonces

I need to send 0.1 ETH to 10 unique addresses from the same address at the same time. I am manually incrementing each transaction's nonce, and the transactions are sent successfully. However, each ...
2 votes
1 answer
7k views

false Transaction mined but execution failed

I was trying to deploy my smart contract to Kovan test network using Remix IDE,although it compiles successfully but when I try to deploy it I get this error message "false Transaction mined but ...
0 votes
0 answers
192 views

ProviderError: Transaction with the same hash was already imported

I'm deploying upgradeable contracts on Kovan, but every time I run my deploy script I get the error. I'm using Hardhat. My deployment script const fs = require('fs') async function main() { let ...
2 votes
2 answers
4k views

"Invalid Chain Id" on Kovan testnet

I'm attempting to initiate a transaction (transfer of ETH) from my main account to a test account on the Kovan Testnet, but I'm getting the error Returned error: Invalid chain id. from the following ...
0 votes
1 answer
66 views

0x Kovan API returning 503 responses?

We have been using the Kovan 0x endpoint (https://kovan.api.0x.org/swap/v1) for a few months without trouble, but just started receiving HTTP 503 responses back today. Is the endpoint still supported ...
0 votes
0 answers
431 views

How to get the contract address based on the transaction hash?

I have the following code which returns the tx hash but when I call upon the receipt it returns null and thus cannot extract the address: const privateKey1Buffer = Buffer.from(privateKey1, 'hex') ...
0 votes
0 answers
57 views

Kovan Network - Transaction has been reverted by the EVM

i'm relatively new to web3 and Ethereum. I'm trying to approve a contract on the Kovan network, which requires 1 DAI to make this transaction. const segmentPayment = await gameContract.methods....
1 vote
1 answer
211 views

Chainlink "Any API" Returning 0

I want to use the chainlink API features but I can not get the data. When I try to execute requestEthereumPrice function I get "uint256: 0" I am using Kovan test net and metamask. pragma ...
1 vote
1 answer
92 views

I'm connecting to the wrong network but my configuration seems right

Trying to run truffle console I got this typical error: I've checked my configuration and it seems OK to me (I don't know why truffle is trying to connect to 127.0.0.1). Here you can see my project: ...
8 votes
3 answers
9k views

Ethereum Testnet mobile app wallet

Is there any Mobile Wallet like Jaxx, but with testnet(like, kovan, ropsten)? Please do suggest me, I am workin on the cryto coin transfer application.
2 votes
1 answer
40 views

Is there a decentralized way to intercommunicate between two Ethereum networks?

If I have Contract A deployed to the Rinkeby Test Netwok If I have Contract B deployed to the Kovan Test Netwok Then, can we program the contracts to interact with each other like Contract A invoking ...