Road To Web3: Week 1 - Mint NFT 🥳

Tutorial Link: https://docs.alchemy.com/docs/how-to-develop-an-nft-smart-contract-erc721-with-alchemy

Side Note: I didn't follow the tutorial exactly but I achieved the same outcome, I modified it to deploy on Polygon & used Hardhat instead of Remix.

View My Minted NFT: https://testnets.opensea.io/assets/mumbai/0x9708005b48b05022293daa6ed5d8b551eebefbf1/1

Interact with my smart contract here: https://mumbai.polygonscan.com/address/0x8542dDdd46b9557CFE3b89075a8c202E48e1ac0b#writeContract

Questions:

1. What was the biggest lesson from this challenge?
   • The biggest lesson for me was learning that an NFTs metadata isn't stored on-chain. I used to think only the image was stored on IPFS but I didn't know that the metadata was stored on IPFS too.
2. What did you like/dislike about this challenge? Why?
   • It was super cool learning how NFTs work & creating metadata that adheres to OpenSea's metadata standard! :)
3. What do you want to build next?
   • Dynamic NFTs!
   • A UI for Minting NFTs.
   • NFTs that you can stake.

How Did I Mint?

1. First, I used OpenZepplin's Smart Contract Wizard to create my ERC21 Smart Contract. see here
2. Then, I added code to only allow 1 mint per user and set the total NFT supply to 10. see here
3. I deployed my contract to Polygon Mumbai & then verified my contract.
   1. Verifying your contract is important because it allows you to interact with your contract directly from PolygonScan! Once your contract is verified, PolygonScan provides a simple UI for read/write functions.
   2. See below for how to verify your contract on PolygonScan from the Command Line.
4. After verifying my contract, I uploaded my image for my NFT to Filebase. Then, I created my metadata file according to OpenSea's metadata standard. see here
   1. Filebase Website for hosting NFT metadata/images on IPFS.
   2. You can view the associated metadata for my NFT in the metadata1.json file. It follows OpenSea's metadata standard.
5. I then connected my wallet & called the safeMint() function with my address & the link to my metadata stored on IPFS.
   1. Address: 0x858C60547fE069724B017c8e42c4b27BE4F151C6
   2. URI: ipfs://QmbJ4tJAgTMuBLUheCYZezjHSKnUwyBYa9qN8xxRxYYXjM
   3. That's it!

Compile your smart contract:

yarn compile

Deploy to Polygon Mumbai testnet:

yarn deploy

Output after deployinh:

Using address 0xC0c630f5c9A78A75a92617852AD0F4E80BF252Cf
Wallet balance 0.7624262968620278
Deploying contract...
Awaiting confirmations
Completed!
Contract deployed to: 0x9708005B48B05022293Daa6ED5D8b551eEBefbF1

Verify Smart Contract on Polygonscan using Hardhat

yarn hardhat verify <YOU-CONTRACT-ADDRESS-HERE> --network mumbai

Output:

Successfully submitted source code for contract
contracts/MintNFT.sol:HelloWorld at 0x9708005B48B05022293Daa6ED5D8b551eEBefbF1
for verification on the block explorer. Waiting for verification result...

Successfully verified contract HelloWorld on Etherscan.
https://mumbai.polygonscan.com/address/0x9708005B48B05022293Daa6ED5D8b551eEBefbF1#code
```# mintNFT