Transfer (SOL)

Before send a tx to transfer SOL, I would like to give you some concept about Solana's tx.

1. a tx = many signatures (the first is the txhash) + one message

2. a message = many accounts + many instructions + one recent blockhash

3. transfer is a kind of instruction

Now back to the topic. Here is the full code.

package main

import (
	"context"
	"log"

	"github.com/portto/solana-go-sdk/client"
	"github.com/portto/solana-go-sdk/common"
	"github.com/portto/solana-go-sdk/program/sysprog"
	"github.com/portto/solana-go-sdk/rpc"
	"github.com/portto/solana-go-sdk/types"
)

// you can fill your key here
var feePayer, _ = types.AccountFromBytes([]byte{178, 244, 76, 4, 247, 41, 113, 40, 111, 103, 12, 76, 195, 4, 100, 123, 88, 226, 37, 56, 209, 180, 92, 77, 39, 85, 78, 202, 121, 162, 88, 29, 125, 155, 223, 107, 139, 223, 229, 82, 89, 209, 27, 43, 108, 205, 144, 2, 74, 159, 215, 57, 198, 4, 193, 36, 161, 50, 160, 119, 89, 240, 102, 184})

// you can fill your key here
var alice, _ = types.AccountFromBytes([]byte{196, 114, 86, 165, 59, 177, 63, 87, 43, 10, 176, 101, 225, 42, 129, 158, 167, 43, 81, 214, 254, 28, 196, 158, 159, 64, 55, 123, 48, 211, 78, 166, 127, 96, 107, 250, 152, 133, 208, 224, 73, 251, 113, 151, 128, 139, 86, 80, 101, 70, 138, 50, 141, 153, 218, 110, 56, 39, 122, 181, 120, 55, 86, 185})

func main() {
	c := client.NewClient(rpc.LocalnetRPCEndpoint)

	// to fetch recent blockhash
	res, err := c.GetRecentBlockhash(context.Background())
	if err != nil {
		log.Fatalf("get recent block hash error, err: %v\n", err)
	}

	// create a message
	message := types.NewMessage(types.NewMessageParam{
		FeePayer:        feePayer.PublicKey,
		RecentBlockhash: res.Blockhash, // recent blockhash
		Instructions: []types.Instruction{
			sysprog.Transfer(sysprog.TransferParam{
				From:   alice.PublicKey,                                                            // from
				To:     common.PublicKeyFromString("2xNweLHLqrbx4zo1waDvgWJHgsUpPj8Y8icbAFeR4a8i"), // to
				Amount: 1e9,                                                                        // 1 SOL
			}),
		},
	})

	// create tx by message + signer
	tx, err := types.NewTransaction(types.NewTransactionParam{
		Message: message,
		Signers: []types.Account{feePayer, alice},
	})
	if err != nil {
		log.Fatalf("failed to new transaction, err: %v", err)
	}

	// send tx
	txhash, err := c.SendTransaction(context.Background(), tx)
	if err != nil {
		log.Fatalf("failed to send tx, err: %v", err)
	}

	log.Println("txhash:", txhash)
}

1. sysprog.Transfer is an instruction which can transfer SOL. The inputs is(from, to, amount) . the from must sign this tx to allow transfer action.

2. feePayer can be anyone, but he/she must sign the tx.

3. you can pass not only one instruction to a tx, so you can do transfer like A => B, B => C, C => A in the same tx.