Grab an account balance from the Ethereum blockchain

main.go

package main

import (
	"context"
	"fmt"
	"log"

	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/ethclient"
)

func main() {
	// Infura is probably not super-secure but good enough for this test,
	// it mimics a fullnode's RPC interface. Alternately we could run an
	// Ethereum full node and connect to that.
	conn, err := ethclient.Dial("https://mainnet.infura.io")
	if err != nil {
		log.Fatalf("Whoops something went wrong connecting to infura: %s", err)
	}

	// An address pulled randomly off Etherscan
	addr := "0xc9d2e0a977983a9f09d9c2452b0d0aab42055773"

	account := common.HexToAddress(addr)
	balance, err := conn.BalanceAt(context.Background(), account, nil)
	if err != nil {
		log.Fatalf("Error getting account balance: %s", err)
	}

	fmt.Println(balance)

}