ccddan / dynamic-nft-chainlink-keepers-vrf-road2web3

Dynamic NFTs w/ Chainlink Keepers/VRF - Road To Web3 by Alchemy - Week 5

Usage

1. Move into smart-contracts and install dependencies: npm install

2. Define required env vars:

   1. Create .env file: cp .env.example .env
   2. Update env vars inside .env with your own values.

3. Compile smart contract: npx hardhat compile

4. Execute tests: npx hardhat test

5. Deploy to Mumbai network: npx hardhat run scripts/deploy.ts --network mumbai

6. Verify your newly deployed contract. Once the previous command finishes the deployment process, you should be able to see the address for your contract in Mumbai network, verify your contract:

   • Parameters:
     • '60': This is the interval to automatically fetch latest BTC price feed and determine the current price trend (Bull/Bear). You can change it for any value you want.
     • '0x007A22900a3B98143368Bd5906f8E17e9867581b': This is the BTC/USD price data feed address. If you change this value, make sure to change it in smart-contracts/scripts/deploy.ts as well.
     • '0x7a1BaC17Ccc5b313516C5E16fb24f7659aA5ebed': VRF Coordinator address (Mumbai).
   • Command: npx hardhat verify --network mumbai <your-contract-addr> '60' '0x007A22900a3B98143368Bd5906f8E17e9867581b' '0x7a1BaC17Ccc5b313516C5E16fb24f7659aA5ebed'

7. Mint a new token. With the account you used to deploy the contract mint a new token directly from Mumbai Polygon Scan web app.

8. Configure Chainlink Keepers

9. Based on the interval you defined and the BTC price, you should be able to see how the metadata for your minted NFT changes automagically over time.

   NOTE: It might be possible that the interval you defined is significantly high or that the price fluctuation of BTC is not does not change the trend (it keeps bull or it keeps bear).

10. (Optional) Randomness. By default, NFTS are generated semi-randomly. Since the VRF coordinator is configured at deployment time, the only think you have to do is to set the subscriptionId.

    1. Create your subscription in Chainlink VRF
    2. From the contract, call setVRFSubscriptionId(<your-sub-id>)
    3. Every time price trend changes, you will ge truly random numbers in your NFTs.