GenSOL

GenSOL is a ERC-721 contract for generative art. Written in Solidity, it is designed to be used with the Foundry framework.

Features

• On-chain metadata (base64 encoded JSON)
• Ability to set maximum supply
• Art is generated from account + token ID + block number
• Contract URI

Contracts

• Generative.sol - The main contract
• BaseGen.sol - The base contract for generative art
• BaseTokenGen.sol - The base contract but payable with ERC-20 tokens

How does it work?

In case of BaseGen.sol we need to define a set of parameters (see script/BaseGen.s.sol)

  address initialOwner = vm.addr(deployerPrivateKey);
  string memory name = "Koda.";
  string memory symbol = "KODA";
  string memory contractURI = "ipfs://bafkreige4zmihk32by3n5aeoq7svlqeyhoaapt4l7hoyspsnr2hm7ljjgq";
  string memory baseURI = "https://dyndata.deno.dev/base/content/"; 
  uint256 maxSupply = 64;
  address receiver = 0xE844b2a0a6453250c920BD2b4B7741946aB16C08;

  BaseGen nft = new BaseGen(initialOwner, name, symbol, contractURI, baseURI, maxSupply, receiver);

As you may know from other NFT Galleries

• contractURI is a link to the contract metadata
• name and symbol are from the ERC-721 standard
• baseURI is a link to the token metadata
  • it is used to generate the tokenURI - baseURI/address(this)/tokenId - where address(this) is the contract address
  • we leverage vikiival/dyndata to generate the metadata
• maxSupply is the maximum number of tokens that can be minted
• receiver is the address that will receive the funds from the minting

Important

The receiver address is a recipient of 5% royalties Function safeMint is payable - you need to send 0.0015 ETH to mint a token

Development

Tip

Last time I wrote a smart contract was in 2019. I am still learning new things in Solidity and code looks like a mess. I am open to any suggestions and improvements.

Prerequisites

• Foundry

Libraries

We use OpenZeppelin contracts for the ERC-721 implementation.

forge install OpenZeppelin/[email protected] --no-commit

Testing the contract

forge test

Deploying the contract

You can simulate a deployment by running the script:

forge script script/Generative.s.sol

To deploy fully with a verification

source .env;
forge script script/BaseGen.s.sol:MyScript --rpc-url $RPC_URL --broadcast --verify -vvvv

alternatively use just

just deploy

Important

You need to have a .env file with the RPC_URL variable set. Do not forget to obtain ehterscan or basescan API key and set it in the .env file.

• https://book.getfoundry.sh/tutorials/solidity-scripting

See Solidity scripting guide for more information.

Reading and resources

Reading

• https://blog.chain.link/how-to-create-generative-art-nfts/

• https://fullyonchain.xyz

• https://brotchain.art/color-editor.html

• https://github.com/ArtBlocks/artblocks-starter-template

• https://blog.thirdweb.com/guides/create-a-generative-art-nft-collection-using-solidity-javascript/

• https://medium.com/coinmonks/creating-generative-art-nfts-with-python-solidity-a95eaeea515e

• https://eips.ethereum.org/EIPS/eip-7572

• https://eips.ethereum.org/EIPS/eip-7496

• https://eips.ethereum.org/EIPS/eip-4906

• https://medium.com/quick-programming/how-to-implement-fully-on-chain-nft-contracts-8c409acc98b7

• https://docs.alchemy.com/docs/how-to-make-nfts-with-on-chain-metadata-hardhat-and-javascript

• https://miningclub.medium.com/how-we-moved-nft-metadata-off-ipfs-and-into-the-smart-contract-59b5db822322

• https://stackoverflow.com/questions/71626871/why-is-my-nft-metadata-not-showing-on-opensea

• https://medium.com/coinmonks/how-to-create-on-chain-nfts-with-solidity-1e20ff9dd87e

• https://forum.openzeppelin.com/t/onchain-nft-metadata-not-json-structure-tokenuri-is-not-showing-up-on-opensea/34932

• https://ethereum.stackexchange.com/questions/124874/nft-metatdata-not-showing-on-opensea

• https://www.reddit.com/r/ethdev/comments/v13sk1/how_to_store_metadata_on_nfts_on_chain_and_how/

• https://www.kevfoo.com/2022/05/opensea-contracturi/