eth_subscribe - Polygon

Example code for the eth_subscribe json-rpc method. Сomplete guide on how to use eth_subscribe json-rpc in GetBlock.io Web3 documentation.

The eth_subscribe method creates a subscription over WebSocket to receive real-time notifications for new blocks, pending transactions, or logs matching specified criteria.

This method requires a WebSocket connection.

Parameters

Parameter

Type

Required

Description

subscriptionType

string

Yes

Subscription type: "newHeads", "newPendingTransactions", "logs"

filterObject

object

Filter options for log subscriptions

Request

curl --location --request POST 'https://go.getblock.io/<ACCESS-TOKEN>/' \
--header 'Content-Type: application/json' \
--data-raw '{
    "jsonrpc": "2.0",
    "method": "eth_subscribe",
    "params": ["newHeads"],
    "id": "getblock.io"
}'

axios request

import axios from 'axios';

const url = 'https://go.getblock.io/<ACCESS-TOKEN>/';

const payload = {
    jsonrpc: '2.0',
    method: 'eth_subscribe',
    params: ["newHeads"],
    id: 'getblock.io'
};

axios.post(url, payload, {
    headers: { 'Content-Type': 'application/json' }
})
.then(response => console.log(response.data))
.catch(error => console.error(error));

requests example

import requests

url = "https://go.getblock.io/<ACCESS-TOKEN>/"

payload = {
    "jsonrpc": "2.0",
    "method": "eth_subscribe",
    "params": ["newHeads"],
    "id": "getblock.io"
}

response = requests.post(url, headers={"Content-Type": "application/json"}, json=payload)
print(response.json())

reqwest example

use reqwest::header;

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let client = reqwest::Client::new();
    
    let response = client
        .post("https://go.getblock.io/<ACCESS-TOKEN>/")
        .header(header::CONTENT_TYPE, "application/json")
        .body(r#"{
            "jsonrpc": "2.0",
            "method": "eth_subscribe",
            "params": ["newHeads"],
            "id": "getblock.io"
        }"#)
        .send()
        .await?;
    
    println!("{}", response.text().await?);
    Ok(())
}

Response

{
    "jsonrpc": "2.0",
    "id": "getblock.io",
    "result": "0x9cef478923ff08bf67fde6c64013158d"
}

Response Parameters

Field

Type

Description

jsonrpc

string

JSON-RPC version (2.0)

string

Request identifier

result

varies

Subscription ID for receiving notifications

Use Case

The eth_subscribe method is useful for:

Real-time block monitoring
Event streaming
Live transaction tracking

Error Handling

Status Code

Error Message

Cause

403

Forbidden

Missing or invalid ACCESS-TOKEN

-32600

Invalid Request

Malformed request body

-32602

Invalid params

Invalid method parameters

Web3 Integration

ethers.js example

import { ethers } from 'ethers';

const provider = new ethers.JsonRpcProvider('https://go.getblock.io/<ACCESS-TOKEN>/');

const result = await provider.send('eth_subscribe', ["newHeads"]);
console.log('Result:', result);

viem example

import { createPublicClient, http } from 'viem';
import { polygon } from 'viem/chains';

const client = createPublicClient({
    chain: polygon,
    transport: http('https://go.getblock.io/<ACCESS-TOKEN>/')
});

const result = await client.request({
    method: 'eth_subscribe',
    params: ["newHeads"]
});
console.log('Result:', result);

Previouseth_sign - Polygon Nexteth_syncing - Polygon

Last updated 27 days ago

Was this helpful?

hashtagParameters

hashtagRequest

hashtagResponse

hashtagResponse Parameters

hashtagUse Case

hashtagError Handling

hashtagWeb3 Integration

Parameters

Request

Response

Response Parameters

Use Case

Error Handling

Web3 Integration