# Go

{% hint style="info" %}
Solana's transaction sending service is no longer bound to the subscription plan, with rate limit default to 3 TPS. API key could be required from [Authentication](/authentication.md). If you need to increase the TPS limit, please [contact](https://discord.com/invite/qqJuwRb8Nh) us and we will handle it as soon as possible.
{% endhint %}

## HTTP <a href="#jiao-yi-gou-jian-dai-ma-shi-li" id="jiao-yi-gou-jian-dai-ma-shi-li"></a>

{% tabs %}
{% tab title="Go" %}

```go
package main

import (
	"bytes"
	"context"
	"encoding/json"
	"fmt"
	"io"
	"math/rand"
	"net/http"
	"time"

	"github.com/gagliardetto/solana-go"
	"github.com/gagliardetto/solana-go/programs/system"
	"github.com/gagliardetto/solana-go/rpc"
)

const (
	httpEndpoint     = "http://frankfurt.solana.blockrazor.xyz:443/sendTransaction"
	healthEndpoint   = "http://frankfurt.solana.blockrazor.xyz:443/health"
	mainNetRPC       = ""
	authKey          = ""
	privateKey       = ""
	publicKey        = ""
	amount           = 200_000
	tipAmount        = 100_000
	mode             = "fast"
	safeWindow       = 5
	revertProtection = false
)

var tipAccounts = []string{
	"Gywj98ophM7GmkDdaWs4isqZnDdFCW7B46TXmKfvyqSm",
	"FjmZZrFvhnqqb9ThCuMVnENaM3JGVuGWNyCAxRJcFpg9",
	"6No2i3aawzHsjtThw81iq1EXPJN6rh8eSJCLaYZfKDTG",
	"A9cWowVAiHe9pJfKAj3TJiN9VpbzMUq6E4kEvf5mUT22",
	"68Pwb4jS7eZATjDfhmTXgRJjCiZmw1L7Huy4HNpnxJ3o",
	"4ABhJh5rZPjv63RBJBuyWzBK3g9gWMUQdTZP2kiW31V9",
	"B2M4NG5eyZp5SBQrSdtemzk5TqVuaWGQnowGaCBt8GyM",
	"5jA59cXMKQqZAVdtopv8q3yyw9SYfiE3vUCbt7p8MfVf",
	"5YktoWygr1Bp9wiS1xtMtUki1PeYuuzuCF98tqwYxf61",
	"295Avbam4qGShBYK7E9H5Ldew4B3WyJGmgmXfiWdeeyV",
	"EDi4rSy2LZgKJX74mbLTFk4mxoTgT6F7HxxzG2HBAFyK",
	"BnGKHAC386n4Qmv9xtpBVbRaUTKixjBe3oagkPFKtoy6",
	"Dd7K2Fp7AtoN8xCghKDRmyqr5U169t48Tw5fEd3wT9mq",
	"AP6qExwrbRgBAVaehg4b5xHENX815sMabtBzUzVB4v8S",
}

var httpClient = &http.Client{
	Timeout: 10 * time.Second,
}

type SendRequest struct {
	Transaction      string `json:"transaction"`
	Mode             string `json:"mode"`
	SafeWindow       int    `json:"safeWindow"`
	RevertProtection bool   `json:"revertProtection"`
}

type SendResponse struct {
	Signature string `json:"signature"`
}
type HealthResponse struct {
	Result string `json:"result"`
}

func main() {
	// Pre-warm: perform an initial health check to establish the HTTP connection
	err := pingHealth()
	if err != nil {
		fmt.Printf("health check failed: %v\n", err)
	}
	// Start a background goroutine to periodically send /health requests
	// For low-frequency users, this keeps the HTTP connection alive (warm)
	go func() {
		for {
			err := pingHealth()
			if err != nil {
				fmt.Printf("health check failed: %v\n", err)
			}
			time.Sleep(30 * time.Second)
		}
	}()
	// send transactions
	if err := sendTx(); err != nil {
		fmt.Printf("send tx failed: %v\n", err)
	}
}

func pingHealth() error {
	req, err := http.NewRequest("GET", healthEndpoint, nil)
	if err != nil {
		return err
	}
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("apikey", authKey)
	resp, err := httpClient.Do(req)
	if err != nil {
		return err
	}
	defer resp.Body.Close()
	// ⚠️ Important Note:
	// According to the Go net/http documentation, in order for the underlying TCP connection
	// to be reused (i.e. kept alive), the response body must be fully read and closed.
	// Otherwise, the Transport may not reuse the connection for future requests.
	// Reference: https://pkg.go.dev/net/http#Response
	// > "The default HTTP client's Transport may not reuse HTTP/1.x 'keep-alive' TCP connections
	//    if the Body is not read to completion and closed."

	// Read the full response body to enable connection reuse
	bodyBytes, _ := io.ReadAll(resp.Body)
	var healthRes HealthResponse
	if err := json.Unmarshal(bodyBytes, &healthRes); err != nil {
		return fmt.Errorf("decode error: %v", err)
	}

	return nil
}

func sendTx() error {
	account, err := solana.WalletFromPrivateKeyBase58(privateKey)
	if err != nil {
		return err
	}
	receivePub := solana.MustPublicKeyFromBase58(publicKey)
	tipPub := solana.MustPublicKeyFromBase58(tipAccounts[rand.Intn(len(tipAccounts))])

	rpcClient := rpc.New(mainNetRPC)
	blockhash, err := rpcClient.GetLatestBlockhash(context.TODO(), rpc.CommitmentFinalized)
	if err != nil {
		return fmt.Errorf("[get blockhash] %v", err)
	}

	transferIx := system.NewTransferInstruction(amount, account.PublicKey(), receivePub).Build()
	tipIx := system.NewTransferInstruction(tipAmount, account.PublicKey(), tipPub).Build()

	tx, err := solana.NewTransaction(
		[]solana.Instruction{tipIx, transferIx},
		blockhash.Value.Blockhash,
		solana.TransactionPayer(account.PublicKey()),
	)
	if err != nil {
		return fmt.Errorf("build tx error: %v", err)
	}

	_, err = tx.Sign(func(key solana.PublicKey) *solana.PrivateKey {
		if account.PublicKey().Equals(key) {
			return &account.PrivateKey
		}
		return nil
	})
	if err != nil {
		return fmt.Errorf("sign tx error: %v", err)
	}

	txBase64, err := tx.ToBase64()
	if err != nil {
		return err
	}

	reqBody := SendRequest{
		Transaction:      txBase64,
		Mode:             mode,
		SafeWindow:       safeWindow,
		RevertProtection: revertProtection,
	}
	jsonBody, _ := json.Marshal(reqBody)

	httpReq, err := http.NewRequest("POST", httpEndpoint, bytes.NewBuffer(jsonBody))
	if err != nil {
		return err
	}
	httpReq.Header.Set("Content-Type", "application/json")
	httpReq.Header.Set("apikey", authKey)
	resp, err := httpClient.Do(httpReq)
	if err != nil {
		return fmt.Errorf("send http error: %v", err)
	}
	defer resp.Body.Close()

	bodyBytes, _ := io.ReadAll(resp.Body)
	var sendRes SendResponse
	if err := json.Unmarshal(bodyBytes, &sendRes); err != nil {
		return fmt.Errorf("decode error: %v", err)
	}
	fmt.Printf("[send tx] response: %+v\n", sendRes)
	return nil
}
```

{% endtab %}

{% tab title="curl" %}

```http
// the following is an example of request in fast mode

curl --request POST \
  --url http://frankfurt.solana.blockrazor.xyz:443/sendTransaction \
  --header 'Content-Type: application/json' \
  --header 'apikey: $auth_token' \
  --data '{
  "transaction":"$base64_tx",
  "mode":"fast",
  "revertProtection":false
}'
```

{% endtab %}
{% endtabs %}

### Response Example <a href="#fan-hui-shi-li" id="fan-hui-shi-li"></a>

**Success**

```http
{"signature":"2DkHpsZxwbGDHkCujRMqd1jXMPaXfzn2JpwxZ43PoTk6Cj7hpxDp8VHESNCeuh95nVMmsWV4RGGWCkmGERZCTWHL","error":""}
```

**Error**

```http
{"signature":"","error":"error: Authentication information is missing. Please provide a valid auth token"}
```

## gRPC <a href="#jiao-yi-gou-jian-dai-ma-shi-li" id="jiao-yi-gou-jian-dai-ma-shi-li"></a>

{% hint style="info" %}
[fast mode](https://github.com/BlockRazorinc/solana-trader-client-go/tree/main/example/grpc/mode_fast)\
[sandwichMitigation mode](https://github.com/BlockRazorinc/solana-trader-client-go/tree/main/example/grpc/mode_sandwichMitigation)
{% endhint %}

```go
package main

import (
	"context"
	"fmt"
	"math/rand"
	"time"

	pb "github.com/BlockRazorinc/solana-trader-client-go/pb/serverpb"

	"github.com/gagliardetto/solana-go"
	"github.com/gagliardetto/solana-go/programs/system"
	"github.com/gagliardetto/solana-go/rpc"
	"google.golang.org/grpc"
	"google.golang.org/grpc/credentials/insecure"
)

const (
	// BlockRazor relay endpoint address
	blzRelayEndpoint = "frankfurt.solana-grpc.blockrazor.xyz:80"
	// replace your solana rpc endpoint
	mainNetRPC = ""
	// replace your authKey
	authKey = ""
	// relace your private key(base58)
	privateKey = ""
	// publicKey(base58)
	publicKey = ""
	// transfer amount
	amount = 200_000
	// send mode
	mode = "fast"
	// safeWindow
	safeWindow = 5
	// revertProtection
	revertProtection = false
	// tip amount
	tipAmount = 100_000
)

var tipAccounts = []string{
	"Gywj98ophM7GmkDdaWs4isqZnDdFCW7B46TXmKfvyqSm",
	"FjmZZrFvhnqqb9ThCuMVnENaM3JGVuGWNyCAxRJcFpg9",
	"6No2i3aawzHsjtThw81iq1EXPJN6rh8eSJCLaYZfKDTG",
	"A9cWowVAiHe9pJfKAj3TJiN9VpbzMUq6E4kEvf5mUT22",
	"68Pwb4jS7eZATjDfhmTXgRJjCiZmw1L7Huy4HNpnxJ3o",
	"4ABhJh5rZPjv63RBJBuyWzBK3g9gWMUQdTZP2kiW31V9",
	"B2M4NG5eyZp5SBQrSdtemzk5TqVuaWGQnowGaCBt8GyM",
	"5jA59cXMKQqZAVdtopv8q3yyw9SYfiE3vUCbt7p8MfVf",
	"5YktoWygr1Bp9wiS1xtMtUki1PeYuuzuCF98tqwYxf61",
	"295Avbam4qGShBYK7E9H5Ldew4B3WyJGmgmXfiWdeeyV",
	"EDi4rSy2LZgKJX74mbLTFk4mxoTgT6F7HxxzG2HBAFyK",
	"BnGKHAC386n4Qmv9xtpBVbRaUTKixjBe3oagkPFKtoy6",
	"Dd7K2Fp7AtoN8xCghKDRmyqr5U169t48Tw5fEd3wT9mq",
	"AP6qExwrbRgBAVaehg4b5xHENX815sMabtBzUzVB4v8S",
}

func main() {
	var err error
	account, err := solana.WalletFromPrivateKeyBase58(privateKey)
	receivePub := solana.MustPublicKeyFromBase58(publicKey)

	// setup grpc connect
	conn, err := grpc.NewClient(blzRelayEndpoint,
		grpc.WithTransportCredentials(insecure.NewCredentials()),
		grpc.WithPerRPCCredentials(&Authentication{authKey}),
	)
	if err != nil {
		panic(fmt.Sprintf("connect error: %v", err))
	}

	// use the Gateway client connection interface
	client := pb.NewServerClient(conn)

	// Pre-warm: perform an initial health check to establish the grpc connection
	err = pingHealth(client)
	if err != nil {
		fmt.Printf("health check failed: %v\n", err)
	}
	// Start a background goroutine to periodically send /health requests
	// For low-frequency users, this keeps the grpc connection alive (warm)
	go func() {
		for {
			err := pingHealth(client)
			if err != nil {
				fmt.Printf("health check failed: %v\n", err)
			}
			time.Sleep(30 * time.Second)
		}
	}()

	// new rpc client and get latest block hash
	rpcClient := rpc.New(mainNetRPC)
	blockhash, err := rpcClient.GetLatestBlockhash(context.TODO(), rpc.CommitmentFinalized)
	if err != nil {
		panic(fmt.Sprintf("[get latest block hash] error: %v", err))
	}

	tipAccount := tipAccounts[rand.Intn(len(tipAccounts))]

	// construct instruction
	transferIx := system.NewTransferInstruction(amount, account.PublicKey(), receivePub).Build()
	tipIx := system.NewTransferInstruction(tipAmount, account.PublicKey(), solana.MustPublicKeyFromBase58(tipAccount)).Build()

	// construct transation, replace your transation
	tx, err := solana.NewTransaction(
		[]solana.Instruction{tipIx, transferIx},
		blockhash.Value.Blockhash,
		solana.TransactionPayer(account.PublicKey()),
	)
	if err != nil {
		panic(fmt.Sprintf("new tx error: %v", err))
	}

	// transaction sign
	_, err = tx.Sign(
		func(key solana.PublicKey) *solana.PrivateKey {
			if account.PublicKey().Equals(key) {
				return &account.PrivateKey
			}
			return nil
		},
	)
	if err != nil {
		panic(fmt.Sprintf("sign tx error: %v", err))
	}

	txBase64, _ := tx.ToBase64()
	sendRes, err := client.SendTransaction(context.TODO(), &pb.SendRequest{
		Transaction:      txBase64,
		Mode:             mode,
		SafeWindow:       safeWindow,
		RevertProtection: revertProtection,
	})
	if err != nil {
		panic(fmt.Sprintf("[send tx] error: %v", err))
	}

	fmt.Printf("[send tx] response: %+v \n", sendRes)
	return
}

type Authentication struct {
	apiKey string
}

func (a *Authentication) GetRequestMetadata(context.Context, ...string) (map[string]string, error) {
	return map[string]string{"apikey": a.apiKey}, nil
}

func (a *Authentication) RequireTransportSecurity() bool {
	return false
}

func pingHealth(client pb.ServerClient) error {
	// grpc request warmup
	healthRes, err := client.GetHealth(context.Background(), &pb.HealthRequest{})
	if err != nil {
		return err
	}
	fmt.Printf("[health] response: %+v \n", healthRes.Status)
	return err
}
```

### Proto <a href="#fan-hui-shi-li" id="fan-hui-shi-li"></a>

```go
syntax = "proto3";

package serverpb;

option go_package = "./pb/serverpb";


service Server {
    rpc SendTransaction(SendRequest) returns(SendResponse) {};

    rpc GetHealth(HealthRequest) returns(HealthResponse) {};
}

message SendRequest {
    string transaction = 1;
    string mode = 2;
    int32 safeWindow = 3; // only take effect in sandwichMitigation mode
    bool revertProtection = 4;
}

message SendResponse {
    string signature = 1;
}

message HealthRequest {
}

message HealthResponse {
    string status = 1;
}
```

### Response Example <a href="#fan-hui-shi-li" id="fan-hui-shi-li"></a>

**Success**

```go
signature:"2PCgCdD5gm4852ooyT2LQqiTgcau28hRNWCqBHCJ33EhhBsuAzAxYGLbS8kAmAMu7DW8JSrrKtaCGMZqQbtbGpgx" 
```

**Error**

```go
error: rpc error: code = Unknown desc = Insufficient tip, please increase the tip amount and try again, at least 1000000 lamports
```


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.blockrazor.io/transaction-submission/fast/solana/send-transaction/go.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.