Smart contracts for NFTs 🦍

A low/no-code solution to create smart contracts for NFTs which can:

• be listed and sold on OpenSea, Rarible
• pay artists royalty from NFT sales (ERC-2981 & Rarible compatible)
• accept fixed commissions when new NFTs are minted

Bootstrapped with Hardhat and Solidity 0.8.4.

Demo 🥽

Polygon smart contract: 0x5df8762bB426C2B72018BA6488717075362a1E30

Important terminology:

• smart contract: a program existing on the blockchain which can create new NFTs
• NFT: a non-fungible token minted/created by users through the smart contract
• commission: a fixed amount of currency received by the smart contract owner whenever a new NFT is minted
• royalties: a percentage of the resale value the original NFT artist (minter) receives

Smart contact functions ⚙️

mint(tokenURI, royaltyPercent) payable

Create a new NFT.

• tokenURI: Link to the NFT metadata (see example)
• royaltyPercent: 0-100 value of the percentage royalty the artist should receive on every sale of the NFT The value of this transaction must be the minimum commission required to mint NFTs on the smart contract. This value is set by the smart contract owner.

setRoyalties(tokenId, royaltiesReceipientAddress, percentage)

Update royalty percentage for an NFT. Only the original artist (minter) can call this function.

• tokenID: ID of the NFT
• royaltiesReceipientAddress: Wallet address of the account which should receive the royalties
• percentage: 0-100 value of the percentage royalty the artist should receive on every sale of the NFT

transferCommission(to)

Transfer the commission received from NFT mints to a given address. Only the smart contract owner can call this function.

Create a new smart contract 📝

Local development

npm i                   # install
npx hardhat compile     # compile
npx hardhat test        # unit test

Deploy on-chain

Create a .env file at the root directory with the following variables:

• POLYGONSCAN_KEY: Polygonscan API key [video tutorial]
• ALCHEMY_URL: Alchemy project key [video tutorial]
• PRIVATE_KEY_DEV: Crypto wallet account private key. You can request some MATIC tokens from the polygon faucet.
• PRIVATE_KEY_PROD: Crypto wallet account private key. Can be the same as PRIVATE_KEY_DEV but I like to use two separate accounts for dev and prod.
• TOKEN_NAME: New name of the NFT smart contract
• TOKEN_SYMBOL: New symbol of the smart contract
• MINT_COMMISSION: The commission given to the contract owner when the mint() function is executed
• MAX_SUPPLY: The maximum number of NFTs that can be minted using the contact. Use -1 for unlimited supply.

Deploy to Polygon mumbai testnet

npx hardhat deploy --network mumbai_dev

Deploy to Polygon mainnet

npx hardhat deploy --network matic_prod

Note: Please ensure you have the minimum number of MATIC tokens in your wallet (roughly 0.008 MATIC, or $0.20 USD - see latest MATIC-USD rate)

Deploy to Ethereum mainnet (untested)

npx hardhat deploy --network eth_prod

Contributing 👋

Contributions are always welcome! Feel free to open any issue or send a pull request. For questions, please contact shanzid.com.