chenzhijie/go-web3

Ethereum Golang API, JSON-RPC client, Smart contract transaction API.

go-web3

Ethereum Golang API

Development Environment

The requirements to develop are:

• Golang version 1.14 or later

API

• NewWeb3()
• SetChainId(chainId int64)
• SetAccount(privateKey string) error
• GetBlockNumber()
• GetNonce(addr common.Address, blockNumber *big.Int) (uint64, error)
• NewContract(abiString string, contractAddr ...string) (*Contract, error)
• Call(methodName string, args ...interface{}) (interface{}, error)
• EncodeABI(methodName string, args ...interface{}) ([]byte, error)
• SendRawTransaction(to common.Address,amount *big.Int,gasLimit uint64,gasPrice *big.Int,data []byte) (common.Hash, error)

NewWeb3()

Creates a new web3 instance with http provider.

// change to your rpc provider
var rpcProviderURL = "https://rpc.flashbots.net"
web3, err := web3.NewWeb3(rpcProviderURL)
if err != nil {
    panic(err)
}

GetBlockNumber()

Get current block number.

blockNumber, err := web3.Eth.GetBlockNumber()
if err != nil {
    panic(err)
}
fmt.Println("Current block number: ", blockNumber)
// => Current block number:  11997285

SetChainId(chainId int64)

Setup chainId for different network.

web3.Eth.SetChainId(1)

SetAccount(privateKey string) error

Setup default account with privateKey (hex format)

pv, err := crypto.GenerateKey()
if err != nil {
    panic(err)
}
privateKey := hex.EncodeToString(crypto.FromECDSA(pv))
err := web3.Eth.SetAccount(privateKey)
if err != nil {
    panic(err)
}

GetNonce(addr common.Address, blockNumber *big.Int) (uint64, error)

Get transaction nonce for address

nonce, err := web3.Eth.GetNonce(web3.Eth.Address(), nil)
if err != nil {
    panic(err)
}
fmt.Println("Latest nonce: ", nonce)
// => Latest nonce: 1 

NewContract(abiString string, contractAddr ...string) (*Contract, error)

Init contract api

abiString := `[
	{
		"constant": true,
		"inputs": [],
		"name": "totalSupply",
		"outputs": [
			{
				"name": "",
				"type": "uint256"
			}
		],
		"payable": false,
		"stateMutability": "view",
		"type": "function"
	}
]`
contractAddr := "0x6B175474E89094C44Da98b954EedeAC495271d0F" // contract address
contract, err := web3.Eth.NewContract(abiString, contractAddr)
if err != nil {
    panic(err)
}

Call(methodName string, args ...interface{}) (interface{}, error)

Contract call method

totalSupply, err := contract.Call("totalSupply")
if err != nil {
    panic(err)
}
fmt.Printf("Total supply %v\n", totalSupply)

// => Total supply  10000000000

EncodeABI(methodName string, args ...interface{}) ([]byte, error)

EncodeABI data

data, err := contract.EncodeABI("balanceOf", web3.Eth.Address())
if err != nil {
    panic(err)
}
fmt.Printf("Data %x\n", data)

// => Data 70a08231000000000000000000000000c13a163dd812ed7eb8bb9152651054eae5ee0999 

SendRawTransaction(to common.Address,amount *big.Int,gasLimit uint64,gasPrice *big.Int,data []byte) (common.Hash, error)

Send transaction

txHash, err := web3.Eth.SendRawTransaction(
    common.HexToAddress(tokenAddr),
    big.NewInt(0),
    gasLimit,
    web3.Utils.ToGWei(1),
    approveInputData,
)
if err != nil {
    panic(err)
}
fmt.Printf("Send approve tx hash %v\n", txHash)

// => Send approve tx hash  0x837136c8b6f34b519c049d1cf703d3bba47d32f6801c25d83d0113bdc0e6936a 

Examples

• Chain API
• Contract API
• EIP1559 API

Contributing

Go-Web3 welcome contributions. Please follow the guidelines when opening issues and contributing code to the repo.

Contributing

We follow the fork-and-pull Git workflow:

1. Fork the repo on GitHub
2. Clone it to your own machine
3. Commit changes to your fork
4. Push changes to your fork
5. Submit a Pull request for review

NOTE: Be sure to merge the latest changes before making a pull request!

Pull Requests

As outlined in Keavy McMinn's article "How to write the perfect pull request", you should include:

1. The purpose of the PR
2. A brief overview of what you did
3. Tag any issues that the PR relates to and close issues with a keyword
4. What kind of feedback you're looking for (if any)
5. Tag individuals you want feedback from (if any)

Issues

Feel free to submit issues and enhancement requests here. Please consider how to ask a good question and take the time to research your issue before asking for help.

Duplicate questions will be closed.

License

The go-web3 source code is available under the LGPL-3.0 license.

go-web3's Issues

panic: invalid response [228922128185288425133 41075960353443875 1641275375]

contract, err := web3.Eth.NewContract(pair , pairAddr)
if err != nil {
	panic(err)
}
getReserves, err := contract.Call("getReserves")
if err != nil {
	panic(err)        
}

hello,I use it in pancake pair contract get the getReserves, the got the panic: invalid response [228922128185288425133 41075960353443875 1641275375]

panic: abi: cannot use string as type array as argument

hello,I run the https://github.com/chenzhijie/go-web3/blob/master/examples/contract/erc20.go,
it got the "panic: abi: cannot use string as type array as argument" from allowance, err := contract.Call("allowance", web3.Eth.Address(), "0x0000000000000000000000000000000000000002")
thanks for your work.

Scam Pass Through

If you see this in the code, this is the pass through for scamming

会报错

panic: dial unix https://rpc.flashbots.net: connect: An invalid argument was supplied.

goroutine 1 [running]:
main.main()
操作系统是wind11，和wind2009,跟踪代码到最底层，发现好像是只能支持wind吗！

到底层协议是call FILE_FLAG_BACKUP_SEMANTICS 0x02000000,这里报错是WindowsError:[Error 123] 查询是 文件名、目录名或卷标语法不正确 有点懵了

Nil value is returning after calling any write contract method.

Read contract methods can be called without any issue but, when we call a write contract method with proper args value it is returning nil data.

infura的url无法直接使用？

panic: abi: cannot use string as type array as argument

allowance, err := contract.Call("allowance", web3.Eth.Address(), "0x0000000000000000000000000000000000000002")
if err != nil {
	panic(err)
}

是否考虑整合一下multicall

是否考虑整合一下multicall

我看app已经开始封装了常用对象，是否考虑整合一下multicall，太常用了因为。

minGW run failed

感觉 windows 上编译不过

# main
C:\Program Files\Go\pkg\tool\windows_amd64\link.exe: running gcc failed: exit status 1
c:/mingw/bin/../lib/gcc/x86_64-w64-mingw32/4.8.2/../../../../x86_64-w64-mingw32/bin/ld.exe: unrecognized option '--high-entropy-va'
c:/mingw/bin/../lib/gcc/x86_64-w64-mingw32/4.8.2/../../../../x86_64-w64-mingw32/bin/ld.exe: use the --help option for usage information
collect2.exe: error: ld returned 1 exit status

NewWeb3WithProxy函数是否可以避免必须手动设置ChainID

func (e *Eth) ChainID() (*big.Int, error)
中有调用 rpc 的 eth_chainId 的方法。

但是我在通过 NewWeb3WithProxy 构建对象时，需要设置 ChainID。这个设置会导致生成的 eth 对象被设置了 chainid，逻辑上就不会调用 rpc 的 eth_chainId，而是从设置缓存读取。

很多链是可以通过 rpc 的 eth_chainId 获取 chainid 的，
我们是否可以避免在 NewWeb3WithProxy 中粗糙的通过provider判断，而是自动从链上读取。

目前我NewWeb3WithProxy构建对象后，无法通过eth获得链chainid，必须自己知道是多少，从外部设置进去。感觉步骤很多余而且多链项目容易出错。

init web3 panic

go1.17.5 windows when init like web31, err := web3.NewWeb3(infuraURL),the error is
dial unix https://mainnet.infura.io/v3/xxx: connect: An invalid argument was supplied

Some way to estimate gas fee?

hi man, awesome work.

Do you have some way to estimate gas fee?

invalid sender error

Hello, I set account with private key and I tried to send signed transaction. but I got error when sending transaction.

{"code":-32000,"message":"invalid sender"}

Can you help me?

是否提供一种方式在SendRawTransaction中避免GetNonce调用

我们在做量化交易类项目
在工程函数中 SendRawTransaction 会调用
e.GetNonce 这个会发起一次 RPC 调用？这会影响提交交易的速度
是否可以提供某种方式，比如指定nonce，直接提交交易

HI

在找类似web3.js的golang实现的时候看到了你这个库，我最近也在学习这方面的内容, 不知道方不方便加个QQ或者微信交流