eth_subscribe - opBNB

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

This method creates a real-time subscription over a WebSocket connection. Available subscription types are newHeads (new block headers), logs (matching contract events), and newPendingTransactions (pending transactions).

This method is only available over WebSocket transport — use wss://go.getblock.io/<ACCESS-TOKEN>/.

Parameters

Parameter

Type

Required

Description

subscriptionType

string

Yes

One of "newHeads", "logs", "newPendingTransactions"

filterObject

object

For "logs": filter with address and/or topics

Request Example

cURL (wscat)

# This method requires WebSocket connection
wscat -c wss://go.getblock.io/<ACCESS-TOKEN>/

> {"jsonrpc":"2.0","method":"eth_subscribe","params":["newheads"],"id":"getblock.io"}

JavaScript (ws)

const WebSocket = require('ws');

const ws = new WebSocket('wss://go.getblock.io/<ACCESS-TOKEN>/');

ws.on('open', () => {
    ws.send(JSON.stringify({
        jsonrpc: '2.0',
        method: 'eth_subscribe',
        params: ['newHeads'],
        id: 'getblock.io'
    }));
});

ws.on('message', (data) => {
    console.log(JSON.parse(data));
});

Python (websockets)

import asyncio
import websockets
import json

async def unsubscribe():
    uri = "wss://go.getblock.io/<ACCESS-TOKEN>/"
    async with websockets.connect(uri) as ws:
        payload = {
            "jsonrpc": "2.0",
            "method": "eth_subscribe",
            "params": ["newHeads"],
            "id": "getblock.io"
        }
        await ws.send(json.dumps(payload))
        response = await ws.recv()
        print(json.loads(response))

asyncio.run(unsubscribe())

Rust (tokio-tungstenite)

use tokio_tungstenite::connect_async;
use futures_util::{SinkExt, StreamExt};
use serde_json::json;

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let url = "wss://go.getblock.io/<ACCESS-TOKEN>/";
    let (mut ws, _) = connect_async(url).await?;
    
    let payload = json!({
        "jsonrpc": "2.0",
        "method": "eth_subscribe",
        "params": ["newHeads"],
        "id": "getblock.io"
    });
    
    ws.send(payload.to_string().into()).await?;
    
    if let Some(msg) = ws.next().await {
        println!("{:?}", msg?);
    }
    
    Ok(())
}

Response Example

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

Response Parameters

Field

Type

Description

result

string

Subscription ID, used to match incoming eth_subscription notifications and to call eth_unsubscribe

Use Cases

Real-time wallet activity notifications
Live DEX trade feeds for trading UIs
Streaming indexers that react to new blocks instantly
Mempool surveillance for MEV bots

Error Handling

Status Code

Error Message

Cause

403

Forbidden

Missing or invalid <ACCESS-TOKEN>

-32602

Invalid params

Request parameters are missing or malformed

-32601

Method not found

The method is not supported by this node

429

Too Many Requests

Rate limit exceeded for your plan

-32600

Invalid Request

eth_subscribe was called over HTTP; use a WebSocket connection instead

SDK Integration

import { ethers } from 'ethers';

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

provider.on('block', (blockNumber) => {
    console.log('New block:', blockNumber);
});

import { createPublicClient, webSocket } from 'viem';
import { opBNB } from 'viem/chains';

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

const unwatch = client.watchBlockNumber({
    onBlockNumber: (blockNumber) => console.log('New block:', blockNumber)
});

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Last updated 14 days ago

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