eth_subscribe - Celo

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

This method creates a subscription for real-time event notifications on the Celo network.

This requires a WebSocket connection and is ideal for tracking new blocks, pending transactions, or contract events with Celo's fast ~1 second block times.

Parameters

Parameter	Type	Required	Description
subscriptionType	string	Yes	Type: "newHeads", "logs", "newPendingTransactions"
options	object	No	Filter options (for "logs" type)

Request Example

JavaScript (newHeads)

subscribe-newHeads.js

const WebSocket = require('ws');

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

ws.on('open', () => {
  ws.send(JSON.stringify({
    jsonrpc: '2.0',
    id: 1,
    method: 'eth_subscribe',
    params: ['newHeads']
  }));
});

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

JavaScript (logs - cUSD Transfers)

Python (websockets)

Response Example

Result

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": "0x9cef478923ff08bf67fde6c64013158d"
}

Subscription Notification

Response Definition

Field	Type	Description
result	string	Subscription ID

Use Cases

• Real-time block notifications

• Live stablecoin transfer tracking

• Pending transaction monitoring

• DeFi event streaming

Error Handling

Error Code	Description
-32602	Invalid subscription type
-32603	Internal error

SDK Integration

Ethers.js

ethers-subscribe.js

const { ethers } = require('ethers');

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

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

Viem