# Public Mempool

### Introduction

`NewTxs` is used to subscribe to the transaction data stream in the high-performance network.



### Endpoint

<table><thead><tr><th width="160">Region</th><th>Availability Zone(AWS)</th><th>Relay Address</th></tr></thead><tbody><tr><td>Frankfurt</td><td>euc1-az2</td><td>35.157.64.49:50051</td></tr><tr><td>Tokyo</td><td>apne1-az4</td><td>54.249.93.63:50051</td></tr><tr><td>Ireland</td><td>euw1-az1</td><td>3.248.65.151:50051</td></tr><tr><td>Virginia</td><td>use1-az4</td><td>52.205.173.134:50051</td></tr></tbody></table>



### Rate Limit

|                       | Tier 4 | Tier 3 | Tier 2 | Tier 1 | Tier 0 |
| --------------------- | ------ | ------ | ------ | ------ | ------ |
| Parallel data streams | -      | 1      | 5      | 10     | 30     |



### Request Parameters

<table><thead><tr><th width="168">Parameters</th><th width="119">Mandatory</th><th width="103">Format</th><th width="98">Example</th><th>Description</th></tr></thead><tbody><tr><td>NodeValidation</td><td>Mandatory</td><td>boolean</td><td>false</td><td>This field currently only supports being set to <code>false</code>, and the relay will push all new transactions (unchecked) with lower latency.</td></tr></tbody></table>



### Request Example

[https://github.com/BlockRazorinc/relay\_example](https://github.com/BlockRazorinc/relay_example)

{% tabs %}
{% tab title="Go" %}
```go
package main

import (
	"context"
	"fmt"

	// directory of the generated code using the provided relay.proto file
	pb "github.com/BlockRazorinc/relay_example/protobuf"
	"github.com/ethereum/go-ethereum/core/types"
	"github.com/ethereum/go-ethereum/rlp"
	"google.golang.org/grpc"
)

// 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.Dial(blzrelayEndPoint, grpc.WithInsecure(), grpc.WithPerRPCCredentials(&auth), grpc.WithWriteBufferSize(0), grpc.WithInitialConnWindowSize(128*1024))
	if err != nil {
		fmt.Println("error: ", err)
		return
	}

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

	// create context and defer cancel of context
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	// create a subscription using the stream-specific method and request
	stream, err := client.NewTxs(ctx, &pb.TxsRequest{NodeValidation: false})
	if err != nil {
		fmt.Println("failed to subscribe new tx: ", err)
		return
	}

	for {
		reply, err := stream.Recv()
		if err != nil {
			fmt.Println("stream receive error: ", err)
		}
		tx := &types.Transaction{}

		err = rlp.DecodeBytes(reply.Tx.RawTx, tx)
		if err != nil {
			continue
		}

		fmt.Println("recieve new tx, tx hash is ", tx.Hash().String())

	}
}
```
{% endtab %}
{% endtabs %}

#### Proto

The code of `relay.proto` is as follows:

```
syntax = "proto3";

package blockchain;

option go_package = "/Users/code/relay/grpcServer"; 
service Gateway {
  rpc SendTx (SendTxRequest) returns (SendTxReply) {}
  rpc SendTxs (SendTxsRequest) returns (SendTxsReply) {}
  rpc NewTxs (TxsRequest) returns (stream TxsReply){}
  rpc NewBlocks (BlocksRequest) returns (stream BlocksReply){}
}

message TxsRequest{
  bool node_validation = 1;
}

message Tx{
  bytes from = 1;
  int64 timestamp = 2;
  bytes raw_tx = 3;
}

message TxsReply{
   Tx tx = 1;
}

message BlocksRequest{
  bool node_validation = 1;
}

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;
  uint64 gas_limit = 10;
  uint64 gas_used = 11;
  uint64 timestamp = 12;
  bytes extra_data = 13;
  string mix_hash = 14;
  uint64 nonce = 15;
  uint64 base_fee_per_gas = 16;
  string withdrawals_root = 17;
  uint64 blob_gas_used = 18;
  uint64 excess_blob_gas = 19;
  string parent_beacon_block_root = 20;
}

message NextValidator{
  string block_height = 1;
  string coinbase = 2;
}

message BlocksReply{
  string hash = 1;
  BlockHeader header = 2;
  repeated NextValidator nextValidator = 3;
  repeated Tx txs = 4;
}

message Transaction {
  string content = 1;
}

message Transactions {
  repeated Transaction transactions = 1;
}

message SendTxRequest {
  string transaction = 1;
}

message SendTxsRequest {
  string transactions = 1;
}

message SendTxReply {
  string tx_hash = 1;
}

message SendTxsReply {
  repeated string tx_hashs = 1;
}
```



### Response Example

**Success**

```json
{
  "tx":[
     {
        "raw_tx":"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"
     }
   ]
}
```

**Error**

```
rpc error: code = Unknown desc = data streams have exceeded its max limit [5]
```