ckb-sdk-go

README

CKB SDK Golang

Golang SDK for Nervos CKB.

The ckb-sdk-go is still under development and considered to be a work in progress. You should get familiar with CKB transaction structure and RPC before using it.

WARNING

Module Indexer has been removed from ckb_v0.40.0: Please use ckb-indexer as an alternate solution.

The following RPCs have been removed from ckb_v0.40.0:

• get_live_cells_by_lock_hash
• get_transactions_by_lock_hash
• index_lock_hash
• deindex_lock_hash
• get_lock_hash_index_states
• get_capacity_by_lock_hash

Since ckb_v0.36.0 SDK use ckb-indexer to collect cells, please see Collect cells for examples.

Installation

Minimum requirements

Components	Version	Description
Golang	≥ 1.11.5	Go programming language

Install

go get -v github.com/nervosnetwork/ckb-sdk-go

Quick start

Sign and send transaction

package main

import (
	"context"
	"encoding/hex"
	"fmt"
	"log"

	"github.com/nervosnetwork/ckb-sdk-go/crypto/secp256k1"
	"github.com/nervosnetwork/ckb-sdk-go/rpc"
	"github.com/nervosnetwork/ckb-sdk-go/transaction"
	"github.com/nervosnetwork/ckb-sdk-go/types"
	"github.com/nervosnetwork/ckb-sdk-go/utils"
)

func main() {
	client, err := rpc.Dial("http://127.0.0.1:8114")
	if err != nil {
		log.Fatalf("create rpc client error: %v", err)
	}

	key, err := secp256k1.HexToKey(PRIVATE_KEY)
	if err != nil {
		log.Fatalf("import private key error: %v", err)
	}

	systemScripts, err := utils.NewSystemScripts(client)
	if err != nil {
		log.Fatalf("load system script error: %v", err)
	}

	toAddress, _ := hex.DecodeString("bf3e92da4911fa5f620e7b1fd27c2d0ddd0de744")
	changeScript, _ := key.Script(systemScripts)

	tx := transaction.NewSecp256k1SingleSigTx(systemScripts)
	tx.Outputs = append(tx.Outputs, &types.CellOutput{
		Capacity: 200000000000,
		Lock: &types.Script{
			CodeHash: types.HexToHash("0x9bd7e06f3ecf4be0f2fcd2188b23f1b9fcc88e5d4b65a8637b17723bbda3cce8"),
			HashType: types.HashTypeType,
			Args:     toAddress,
		},
	})
	tx.Outputs = append(tx.Outputs, &types.CellOutput{
		Capacity: 199999998000,
		Lock: &types.Script{
			CodeHash: types.HexToHash("0x9bd7e06f3ecf4be0f2fcd2188b23f1b9fcc88e5d4b65a8637b17723bbda3cce8"),
			HashType: types.HashTypeType,
			Args:     changeScript.Args,
		},
	})
	tx.OutputsData = [][]byte{{}, {}}

	group, witnessArgs, err := transaction.AddInputsForTransaction(tx, []*types.CellInput{
		{
			Since: 0,
			PreviousOutput: &types.OutPoint{
				TxHash: types.HexToHash("0x8e6d818c6e07e6cbd9fca51294030494ee23dc388d7f5276ba50b938d02cc015"),
				Index:  1,
			},
		},
	}, uint(len(transaction.Secp256k1SignaturePlaceholder)))

	if err != nil {
		log.Fatalf("add inputs to transaction error: %v", err)
	}

	err = transaction.SingleSignTransaction(tx, group, witnessArgs, key)
	if err != nil {
		log.Fatalf("sign transaction error: %v", err)
	}

	hash, err := client.SendTransaction(context.Background(), tx)
	if err != nil {
		log.Fatalf("send transaction error: %v", err)
	}

	fmt.Println(hash.String())
}

Create a new address

In CKB world, a lock script can be represented as an address. secp256k1_blake160 is the most common used address and here we show how to generate it.

addressGenerateResult, error := GenerateAddress(Testnet)

For more details please about CKB address refer to CKB rfc 0021 .

Convert public key to address

Convert elliptic curve public key to an address (secp256k1_blake160)

address, err := ConvertPublicToAddress(Mainnet, "0xb39bbc0b3673c7d36450bc14cfcdad2d559c6c64")

Convert short/bech32 address to bech32m address

Short address and bech32 address are deprecated. The standard address format is bech32m-encoded long address, which can be got from the short address or bech32 address as the following snippet code.

bech32mFullAddress, err := ConvertToBech32mFullAddress("ckt1qyqxgp7za7dajm5wzjkye52asc8fxvvqy9eqlhp82g")

Parse and validate address

parsedAddress, err := Parse("ckt1qg8mxsu48mncexvxkzgaa7mz2g25uza4zpz062relhjmyuc52ps3zn47dugwyk5e6mgxvlf5ukx7k3uyq9wlkkmegke")

Mercury

Mercury is a development service in CKB ecosystem, providing many useful RPC APIs for development like querying transaction or getting udt asset information. You need to deploy your own mercury and sync data with the network before using it.

ckb-sdk-go also integrate with Mercury. For usage guide, please check the example folder.

License

The SDK is available as open source under the terms of the MIT License.