chainlink | decentralized oracle network | Blockchain library
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kandi X-RAY | chainlink Summary
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QUESTION
I created my own eternal Adapter, that retruns a string as result. The node runs the job correctly and woun't give any error. I think the error happens in the smart contract.
Here is my current smart contract, edited from the Chainlink docs.
...ANSWER
Answered 2022-Mar-14 at 22:10Send ETH to your chainlink oracle address.
QUESTION
Thanks to Patrick and after reading the Chainlink's blog on how to build blockchain lottery, I am eager to build a similar "version". It will be using the latest Chainlink's version of VRFv2 and Keeper.
However, the supported test networks for VRFv2 and Keeper are Rinkeby and Kovan, respectively.
So any hint on how to approach this?
...ANSWER
Answered 2022-Mar-14 at 17:39For now the one of the only testnet's both Keepers and VRF v2 are available on is the BNB testnet. You can test your application there until VRF v2 and keepers are available on the same Ethereum testnet.
References:
Keepers Supported Chains
VRF v2 Supported Chains
QUESTION
While trying to set up a basic self-hosted unit testing environment (and CI) that tests this Chainlink VRF random number contract, I am experiencing slight difficulties in how to simulate any relevant blockchains/testnets locally.
For example, I found this repository that tests Chainlinks VRF. However, for default deployment it suggests/requires a free KOVAN_RPC_URL e.g. from Infura's site and even for "local deployment" it suggests/requires a free MAINNET_RPC_URL from e.g. Alchemy's site.
I adopted a unit test environment from the waffle framework which is described as:
Filestructure ...ANSWER
Answered 2021-Sep-09 at 04:35to test locally you need to make use of mocks which can simulate having an oracle network. Because you're working locally, a Chainlink node doesn't know about your local blockchain, so you can't actually do proper VRF requests. Note you can try deploy a local Chainlink node and a local blockchain and have them talk, but it isn't fully supported yet so you may get mixed results. Anyway, as per the hardhat starter kit that you linked, you can set the defaultNetwork to be 'hardhat' in the hardhat.config.js file, then when you deploy and run the integration tests (yarn test-integration), it will use mocks to mock up the VRF node, and to test the requesting of a random number. See the test here, and the mock contracts and linktoken get deployed here
QUESTION
I am working on a project that will need to use ChainLink to make external API calls from the Ethereum blockchain. I was testing out the demo code like so:
...ANSWER
Answered 2022-Feb-28 at 20:49Gas estimation error is a common error meaning that you don't have enough of "something" to send your transaction, maybe it's layer 1 (ETH) gas, or an ERC20 token like LINK (technically, erc677, but I digress...)
Whenever you work with a Chainlink feature that uses the request and receive method of using chainlink, you need to fund the consumer contract with LINK token.
The issue here is you sent LINK to the oracle address and not the address of your deployed contract.
If you copy the address of your deployed contract and send the LINK there, it should work for you.
QUESTION
I'm trying to write a smart contract to transfer eth from one metamask wallet to another metamask wallet in solidity in remix with Injected Web 3 environment. I deployed the contract but the transaction send_ETH failed. Could anyone help me figure out why? Thank you so much
ANSWER
Answered 2022-Feb-20 at 23:49your function invest() is wrong
QUESTION
I tried all that you mentioned in the discussion here (in other questions) and at https://github.com/smartcontractkit/full-blockchain-solidity-course-py/discussions/522 , however it is not solving the issue for me, I also noticed that the current compiler version remains (current compiler is 0.6.12+commit.27d51765.Windows.msvc). But when I right click and select Solidty:Compiler information, it shows 0.8.0.
from output:
...ANSWER
Answered 2022-Jan-02 at 03:09i had the same issue. i had this compiler setting:
QUESTION
I was eventually trying to run this code in remix IDE, where I was running this using 0.6.6 version of Solidity and ran into this error. I've tried using some other versions like 0.8 and 0.6 as well.
...ANSWER
Answered 2022-Jan-29 at 13:14Your code requires Solidity 0.8.7, but the imported SafeMathChainlink.sol requires Solidity 0.6.*.
An easy solution is to change your code to require v0.6 as well and compile with this version.
QUESTION
For reproducing the error, the code can be taken from https://github.com/Binoy-John/brownie_fund_me
So I have a contract FundMe.sol, which has several functions one of them being getEntranceFee(). It is as shown below:
...ANSWER
Answered 2022-Jan-27 at 11:40function getPrice() public view returns (uint256) {
(, int256 answer, , , ) = priceFeed.latestRoundData();
// ETH/USD rate in 18 digit
return uint256(answer * 10000000000);
}
QUESTION
I have a simple brownie project with a deploy.py and a solidity file. Both projects are fine. I get the same error, even though I delete the content in both files.
...ANSWER
Answered 2022-Jan-25 at 10:21I got it. I have a spelling mistake in my brownie-config.yaml file. Instead of the / I need a =.
I had:
QUESTION
I took the example from the official ChainLink Any API Large Response docs and deployed it to the kovan network without any changes.
The contract: https://kovan.etherscan.io/address/0x1B0beB43a03591bc7f8B5eFf1F0bfB8400e12a63
Compiler: 0.8.7+commit.e28d00a7
I also verified it's code to be sure that it matches with the example from docs, fund it with 2 LINK tokens. Then I called requestBytes method twice, one 8 hours ago and another 7 hours ago:
Both finished without any errors, but when i'm reading data and image_url they're empty:
Getting uint256 works fine, the problem arises only with Large Responses.
ANSWER
Answered 2022-Jan-19 at 18:54That demo broke due to API changes in the ChainlinkClient and Operator.sol contracts.
The demo has now been updated and should work. Note that the function for sending the Chainlink request has changed to sendOperatorRequest() (for large response requests.)
Community Discussions, Code Snippets contain sources that include Stack Exchange Network
Vulnerabilities
No vulnerabilities reported
Install chainlink
Install Go 1.17, and add your GOPATH's bin directory to your PATH Example Path for macOS export PATH=$GOPATH/bin:$PATH & export GOPATH=/Users/$USER/go
Install NodeJS 12.22 & Yarn It might be easier long term to use nvm to switch between node versions for different projects: nvm install 12.22 && nvm use 12.22
Install Postgres (>= 11.x). You should configure Postgres to use SSL connection (or for testing you can set ?sslmode=disable in your Postgres query string).
Ensure you have Python 3 installed (this is required by solc-select which is needed to compile solidity contracts)
Download Chainlink: git clone https://github.com/smartcontractkit/chainlink && cd chainlink
Build and install Chainlink: make install If you got any errors regarding locked yarn package, try running yarn install before this step If yarn install throws a network connection error, try increasing the network timeout by running yarn install --network-timeout 150000 before this step
Run the node: chainlink help
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