> For the complete documentation index, see [llms.txt](https://docs.blockrazor.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.blockrazor.io/tc/transaction-submission/fast/ethereum/broadcast-tx.md).
# Broadcast Tx
### 什麼是 Broadcast Tx
Broadcast Tx 是 BlockRazor 提供的一種快速交易發送服務，用於幫助用戶以更低延遲將交易發送到鏈上。它屬於 Fast 體系的一部分，但與需要在交易中附加 tip 的標準 Fast 模式不同，Broadcast Tx 不要求用戶在交易內部額外支付 tip，因此更適合作為低門檻的快速發送入口使用。
目前Ethereum Broadcast Tx提供 `SendTx` 方法，用来發送单笔交易。
需要注意的是，Broadcast Tx 雖然屬於 Fast 體系，但它並不等同於具備完整交易保護能力的私有發送通道。Broadcast Tx 發送的交易會進入公開傳播路徑，因此不具備 MEV 防護能力。
### 什麼場景下選擇 Broadcast Tx
* **不需要 tip，接入門檻更低**\
與標準 Fast 模式不同，Broadcast Tx 不要求在交易中附加 tip，因此更適合希望快速接入、但不想修改交易激勵結構的用戶。
* **適合對速度有要求、但暫不強調 MEV 防護的場景**\
如果你的重點是盡量更快地把交易發出去，而不是通過私有路徑隱藏交易或抵御 sandwich、frontrunning 等風險，那麼 Broadcast Tx 會是一個更直接的選擇。
### 端點
地區
可用區（AWS）
Relay IP:Port
法蘭克福
euc1-az2
64.130.47.75:50061
東京
apne1-az4
63.254.162.18:50061
弗吉尼亞
use1-az4
208.91.105.204:50061
### 價格
用戶類型
限流
價格
新註冊用戶
SendTx
TPS：10 Txs / 5s
每日交易上限：10
免費
付費用戶
SendTx
TPS：100 Txs / 5s
每日交易上限：100000
$500 / 月
### SendTx
#### **請求參數**
參數
必選
格式
示例
描述
Transaction
是
String
"0xf8……8219"
經過簽名的rawtx
#### **請求示例**
{% tabs %}
{% tab title="gRPC" %}
```go
package main
import (
"context"
"fmt"
"math/big"
"time"
// directory of the generated code using the provided relay.proto file
pb "github.com/BlockRazorinc/eth_relay_example/protobuf"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core/types"
"github.com/ethereum/go-ethereum/crypto"
"google.golang.org/grpc"
"google.golang.org/grpc/credentials/insecure"
)
// auth will be used to verify the credential
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 main() {
// BlockRazor relay endpoint address
blzrelayEndPoint := "ip:port"
// auth will be used to verify the credential
auth := Authentication{
"your auth token",
}
// open gRPC connection to BlockRazor relay
var err error
conn, err := grpc.NewClient(blzrelayEndPoint, grpc.WithTransportCredentials(insecure.NewCredentials()), grpc.WithPerRPCCredentials(&auth), grpc.WithWriteBufferSize(0), grpc.WithInitialConnWindowSize(128*1024))
if err != nil {
fmt.Println("error: ", err)
return
}
defer conn.Close()
// use the Relay client connection interface.
client := pb.NewRelayClient(conn)
// create context
ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
defer cancel()
// replace with your address
fromPrivateAddress := "42b565......44d05c"
toPublicAddress := "0x4321......3f1c66"
// replace with your transaction data
nonce := uint64(1)
toAddress := common.HexToAddress(toPublicAddress)
var data []byte
gasLimit := uint64(21000)
value := big.NewInt(0)
chainID := big.NewInt(1)
gasTipCap := big.NewInt(2_000_000_000)
gasFeeCap := big.NewInt(30_000_000_000)
// create new EIP-1559 transaction
tx := types.NewTx(&types.DynamicFeeTx{
ChainID: chainID,
Nonce: nonce,
GasTipCap: gasTipCap,
GasFeeCap: gasFeeCap,
Gas: gasLimit,
To: &toAddress,
Value: value,
Data: data,
})
privateKey, err := crypto.HexToECDSA(fromPrivateAddress)
if err != nil {
fmt.Println("fail to casting private key to ECDSA")
return
}
// sign transaction by private key
signedTx, err := types.SignTx(tx, types.LatestSignerForChainID(chainID), privateKey)
if err != nil {
fmt.Println("fail to sign transaction")
return
}
// marshal signed transaction to raw binary bytes
rawTx, err := signedTx.MarshalBinary()
if err != nil {
fmt.Println("fail to marshal signed transaction")
return
}
// send raw tx by BlockRazor
res, err := client.SendTx(ctx, &pb.SendTxRequest{RawTx: rawTx})
if err != nil {
fmt.Println("failed to send raw tx: ", err)
return
}
fmt.Println("raw tx sent by BlockRazor, tx hash is ", res.TxHash)
}
```
{% endtab %}
{% endtabs %}
#### 返回示例
**正常**
```json
{
"tx_hash":"0x2944……b2188f"
}
```
**异常**
```
rpc error: code = Unknown desc = invalid transaction format
```
### Proto
`relay.proto`文件代碼如下：
```go
syntax = "proto3";
package relay.v1;
option go_package = "github.com/BlockRazorinc/eth_relay_example/protobuf";
service Relay {
rpc SendTx(SendTxRequest) returns (SendTxReply);
rpc NewTxs(NewTxsRequest) returns (stream NewTx);
rpc NewBlocks(NewBlocksRequest) returns (stream NewBlock);
}
message SendTxRequest {
bytes raw_tx = 1;
}
message SendTxReply {
string tx_hash = 1;
}
message NewTxsRequest {
bool include_raw_tx = 1;
}
message NewTx {
string tx_hash = 1;
bytes raw_tx = 2;
int64 first_seen_unix_ns = 3;
string source = 4;
}
message NewBlocksRequest {
bool parsed_txs = 1;
}
message NewBlock {
string hash = 1;
BlockHeader header = 2;
repeated BlockTransaction transactions = 3;
repeated Withdrawal withdrawals = 4;
}
message BlockHeader {
string parent_hash = 1;
string sha3_uncles = 2;
string miner = 3;
string state_root = 4;
string transactions_root = 5;
string receipts_root = 6;
string logs_bloom = 7;
string difficulty = 8;
string number = 9;
string gas_limit = 10;
string gas_used = 11;
string timestamp = 12;
string extra_data = 13;
string mix_hash = 14;
string nonce = 15;
string base_fee_per_gas = 16;
string withdrawals_root = 17;
string blob_gas_used = 18;
string excess_blob_gas = 19;
string parent_beacon_block_root = 20;
}
message BlockTransaction {
bytes raw_tx = 1;
bytes from = 2;
}
message Withdrawal {
string address = 1;
string amount = 2;
string index = 3;
string validator_index = 4;
}
```
### 代码示例
---
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