ABI directly on chain

index.js

const fs = require('fs');
const zlib = require('zlib');
const Web3 = require('web3');
const solc = require('solc');


(async function() {

// Stick whatever metadata you want in a zip
const file = fs.readFileSync('VerifiedGroup.abi');
const zip = zlib.gzipSync(file);

console.log('Zipped size', zip.length, 'Original Size', file.length);

// Embed the zip into a contract
const input = {
  language: 'Solidity',
  sources: {
    'test.sol': {
      content: `
        contract Test {
          function data() public pure returns (bytes memory out) {
            out = hex"${zip.toString('hex')}";
          }
        }`
    }
  },
  settings: {
    outputSelection: {
      '*': {
        '*': ['*']
      }
    }
  }
};

const output = JSON.parse(solc.compile(JSON.stringify(input)));
const abi = output.contracts['test.sol']['Test'].abi;
const data = output.contracts['test.sol']['Test'].evm.bytecode.object;

// Deploy to test Ganache chain
const web3 = new Web3('http://localhost:8545');

const accounts = await new Promise((resolve, reject) => {
  web3.eth.getAccounts((error, accounts) => {
    if(error) reject(error);
    else resolve(accounts);
  });
});

const contract = new web3.eth.Contract(abi);
console.log('Super simple ABI for retrieving', JSON.stringify(abi, null, 2));
const deployment = contract.deploy({ data });
const gas = await deployment.estimateGas();
const deployed = await deployment.send({ from: accounts[0], gas });
console.log('Deployed to', deployed.options.address);

// Read back the data
const contract2 = new web3.eth.Contract(abi, deployed.options.address);
const fromContract = await contract2.methods.data().call();
const unzip = zlib.gunzipSync(Buffer.from(fromContract.slice(2), 'hex'));
console.log(unzip.toString('utf8'));

})();

output.txt

$ node index.js 
Zipped size 882 Original Size 8506
Super simple ABI for retrieving [
  {
    "inputs": [],
    "name": "data",
    "outputs": [
      {
        "internalType": "bytes",
        "name": "out",
        "type": "bytes"
      }
    ],
    "stateMutability": "pure",
    "type": "function",
    "constant": true,
    "signature": "0x73d4a13a"
  }
]
Deployed to 0xA9D374AAcC3fe3395470eDeBA7266f1DA6f73fcd
[{"inputs": ...