ethclient: A Go repository from ackermanx

Introduction

ethclient is extend go-ethereum client for interact with smart contract.

Features:

query token balance
calculate uniswap v2/v3 liquid pool address offline
sort token address
encode uniswap v3 path
uniswap v3 liquid pool x96 price format convert
query smart contract data
build contract transaction and main currency transaction
HD wallet

Install

go get -u github.com/ackermanx/ethclient

Usage

Below is an example which shows some common use cases for ethereum/client. Check client_test.go for more usage.

get balance/token balance/token transfer/main currency transfer

package main

import (
	"context"
	"log"
	"math/big"
	"time"

	"github.com/ackermanx/ethclient"
	"github.com/ackermanx/ethclient/abi"
	"github.com/ethereum/go-ethereum/accounts/abi/bind"
	"github.com/ethereum/go-ethereum/common"
)

var (
	testKey = "33f46d353f191f8067dc7d256e9d9ee7a2a3300649ff7c70fe1cd7e5d5237da5"
)

func main() {
	var binanceMainnet = `https://data-seed-prebsc-1-s1.binance.org:8545`

	ctx, cancel := context.WithTimeout(context.Background(), time.Second*5)
	c, err := ethclient.DialContext(ctx, binanceMainnet)
	cancel()
	if err != nil {
		panic(err)
	}

	// get latest height
	ctx, cancel = context.WithTimeout(context.Background(), time.Second*5)
	blockNumber, err := c.BlockNumber(ctx)
	cancel()
	if err != nil {
		panic(err)
	}
	log.Println("latest block number: ", blockNumber)

	// get busd balance
	busdContractAddress := common.HexToAddress("0xed24fc36d5ee211ea25a80239fb8c4cfd80f12ee")
	address := "0xe96e6b50db659935878f6f3b0491B7F192cf5F59"
	bnbBalance, err := c.BalanceAt(context.Background(), common.HexToAddress(address), nil)
	if err != nil {
		panic(err)
	}
	log.Println("bnbBalance: ", bnbBalance.String())
	balance, err := c.BalanceOf(address, busdContractAddress.String())
	if err != nil {
		panic(err)
	}
	log.Printf("address busd balance: %s\n", balance.String())

	// build contract transfer
	tx, err := c.BuildContractTx(
		testKey, "transfer",
		abi.ERC20Abi,
		&busdContractAddress, &bind.TransactOpts{From: common.HexToAddress(address)},
		common.HexToAddress("0x38F32C2473a314d447d681D30e1C0f5D07194371"),
		big.NewInt(100000000000000000),
	)
	if err != nil {
		panic(err)
	}
	err = c.SendTransaction(context.Background(), tx)
	if err != nil {
		panic(err)
	}
	log.Println(tx.Hash().String())

	// send bnb
	tx, err = c.BuildTransferTx(testKey, "0x38F32C2473a314d447d681D30e1C0f5D07194371", &bind.TransactOpts{
		From:     common.HexToAddress("0xe96e6b50db659935878f6f3b0491b7f192cf5f59"),
		Value:    big.NewInt(20000000000000000),
		GasLimit: 21000,
	})
	if err != nil {
		panic(err)
	}
	log.Println(tx.Hash().String())
	err = c.SendTransaction(context.Background(), tx)
	if err != nil {
		panic(err)
	}
}

generate pool address offline

package main

import (
	"fmt"
	"math/big"

	"github.com/ackermanx/ethclient/uniswap"
)

func main() {
	weth := "0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2"
	dai := "0x6b175474e89094c44da98b954eedeac495271d0f"
	pair, err := uniswap.CalculatePoolAddressV2(weth, dai)
	if err != nil {
		panic(err)
	}

	fmt.Printf("weth-dai pair address in uniswap v2: %s\n", pair.String())

	fee := big.NewInt(3000)
	poolAddress, err := uniswap.CalculatePoolAddressV3(weth, dai, fee)
	if err != nil {
		panic(err)
	}
	fmt.Printf("weth-dai pool address in uniswap v3: %s\n", poolAddress.String())
}

JetBrains OS licenses

ethereum had been being developed with GoLand under the free JetBrains Open Source license(s) granted by JetBrains s.r.o., hence I would like to express my thanks here.