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VRF is a secure verifiable random number on the chain. It is used to generate secure random numbers. For details, see the ChainLink VRF official documentation.
This sample code demonstrates how to use ChainLink for NFT blind box design.
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Configure the private key The private key put in .env in the format "PRIVATE_KEY= XXXX ", from which the code automatically reads.
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Get Link test coins Every time you go to ChainLink to request VRF random number, you need to consume Link coins. Therefore, you need to apply for Link test coins before the test. For the Kovan test network, go to Request testnet LINK , Then "Netwrok" selects "Ethereum Kovan" and "Testnet Account Address "enters the account address corresponding to PRIVATE_KEY in the .env file
- Install Dependencies
npm install
- Create ChainLink SubscriptionID
Login ChainLink VRF Test network , Click on "Create Subscription" to Create a SubscriptionID and you can see the created SubscriptionID under "My Subscriptions"
- Save SubscriptionID
Save the SubscriptionID created in the previous step to .env
## .env
SubscriptionId=ddddd
- Configuring Environment Variables .env file into the private key and infura node ID
## .env
PRIVATE_KEY=xxxxxxxxxxxxxxxx
INFURA_ID=yyyyyyyy
- Deployment test contract
npx hardhat run scripts/deploy.js --network rinkeby
- Get random number
npx hardhat run scripts/random-number-vrf.js --network rinkeby
- Generate random Character
npx hardhat run scripts/transaction.js --network rinkeby
Github sample code: https://github.com/PatrickAlphaC/dungeons-and-dragons-nft
Chainlink Reporting Overview of Off-Chain: https://learnblockchain.cn/article/2186
How to obtain random numbers in NFT(ERC721): https://learnblockchain.cn/article/1776
Develop a DeFi project in 10 minutes using Chainlink predictor: https://learnblockchain.cn/article/1056
chainlink kovan faucet: https://faucets.chain.link/kovan?_ga=2.35440098.2104755910.1637393798-1377742816.1635817935
ChainLink VRF official document: https://docs.chain.link/docs/get-a-random-number/