Snippet for supplying ETH to Compound Protocol via Web3.sj

supply-eth-via-json-rpc.js

// Mint some cETH by supplying ETH to the Compound Protocol
console.log('Sending ETH to the Compound Protocol...');
compoundCEthContract.methods.mint().send({
  from: myWalletAddress,
  gasLimit: web3.utils.toHex(150000),      // posted at compound.finance/developers#gas-costs
  gasPrice: web3.utils.toHex(20000000000), // use ethgasstation.info (mainnet only)
  value: web3.utils.toHex(web3.utils.toWei('1', 'ether'))
}).then((result) => {
  console.log('cETH "Mint" operation successful.');
  return compoundCEthContract.methods
    .balanceOfUnderlying(myWalletAddress).call();
}).then((balanceOfUnderlying) => {
  balanceOfUnderlying = web3.utils.fromWei(balanceOfUnderlying).toString();
  console.log("ETH supplied to the Compound Protocol:", balanceOfUnderlying);
  return compoundCEthContract.methods.balanceOf(myWalletAddress).call();
}).then((cTokenBalance) => {
  cTokenBalance = (cTokenBalance / 1e8).toString();
  console.log("My wallet's cETH Token Balance:", cTokenBalance);
}).catch((error) => {
  console.error(error);
});