slotSubscribe – Solana

The slotSubscribe RPC Solana method allows clients to subscribe to receive notifications whenever a slot is processed by the validator.

The slotSubscribe RPC Solana method establishes a WebSocket connection that notifies clients when a new slot is set.

This is particularly useful for applications that require live updates on the Solana blockchain. Developers can use this method to track transaction processing, blockchain synchronization, and block validation.

Supported Networks

• Mainnet

• Devnet

Parameters

None: This method does not require any parameters.

Result

Returns a subscription ID, which is required for unsubscribing from notifications.

Result Format

• integer: The subscription ID needed to unsubscribe.

Request Example

API Endpoints

wss://go.getblock.io/<ACCESS-TOKEN>/

JSON-RPC Request

wss

wscat -c "wss://go.getblock.io/<ACCESS-TOKEN>/" --exec '{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "slotSubscribe"
}'

Response

A successful request returns a subscription ID.

Example Response

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

In this response:

• result: 0 represents the assigned subscription ID.

Notification Format

Upon slot updates, clients receive notifications containing slot details.

Example Notification

{
  "jsonrpc": "2.0",
  "method": "slotNotification",
  "params": {
    "result": {
      "parent": 75,
      "root": 44,
      "slot": 76
    },
    "subscription": 0
  }
}

Notification Fields

• parent: The parent slot.

• root: The current root slot.

• slot: The newly set slot value.

Error Handling

Common slotSubscribe error scenarios:

• Network issues: Problems with the Solana JSON-RPC API endpoints.

• Invalid WebSocket connection: Issues with maintaining a stable connection.

Example Error Response

{
  "jsonrpc": "2.0",
  "error": {
    "code": -32000,
    "message": "WebSocket connection error"
  },
  "id": 1
}

Use Cases

The Solana slotSubscribe method is essential for:

• Live blockchain monitoring.

• Tracking real-time slot updates for validators and explorers.

• Keeping applications in sync with the Solana blockchain.

• Enhancing dApps by ensuring transaction validation and block consistency.

Code slotSubscribe Example – Web3 Integration

JavaScript

const WebSocket = require('ws');

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

ws.on('open', () => {
  const payload = {
    jsonrpc: "2.0",
    id: 1,
    method: "slotSubscribe"
  };
  ws.send(JSON.stringify(payload));
});

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

ws.on('error', (error) => {
  console.error("WebSocket error:", error.message);
});

ws.on('close', () => {
  console.log("WebSocket connection closed");
});

Integration with Web3

By integrating Web3 slotSubscribe into Solana's Core API, developers can:

• Monitor slot progression in real-time.

• Enhance dApps with live updates.

• Improve blockchain data tracking systems.

• Ensure API requests are processed efficiently.

• Track block synchronization to optimize transactions and block validation.

This method is a critical component of the Core API that enables efficient block tracking, request handling, and transaction updates in Solana-based applications.