web3.js

import Web3 from 'web3';

web3 = new Web3();
const provider = wallet.getProvider();
web3.setProvider(provider);

const walletAddress = await web3.eth.getCoinbase();

// sign
web3.eth.sign("Hello world", walletAddress);

// send transaction
web3.eth.sendTransaction({
    from: walletAddress,
    to: "0x812D3C67d283F3b9d1F1E347DF37F0C7fbD6a0B0",
    value: "1000000000000000000"
});