Polkadot WebSocket RPC

Stream Polkadot data in real time over a WebSocket connection — new blocks, pending transactions, and contract events — instead of polling. Every SwiftNodes plan includes a Polkadot WebSocket endpoint alongside HTTP, with flat-rate pricing and no KYC.

Endpoint

wss://rpc.swiftnodes.io/ws/polkadot?key=YOUR_API_KEY

The HTTP endpoint for Polkadot is https://rpc.swiftnodes.io/rpc/polkadot?key=YOUR_API_KEY. One API key works for both, and across all 75+ supported chains.

Subscribe to Polkadot in real time

import { Connection } from "@solana/web3.js";

const conn = new Connection("https://rpc.swiftnodes.io/rpc/polkadot?key=YOUR_API_KEY", {
  wsEndpoint: "wss://rpc.swiftnodes.io/ws/polkadot?key=YOUR_API_KEY",
});

// Subscribe to new slots on Polkadot
const subId = conn.onSlotChange((slot) => console.log("slot", slot.slot));

What you can subscribe to

• Slot and root updates — track chain progress in real time
• Account changes — get notified when an account's data updates
• Program and signature subscriptions for live app state

Polkadot is a Layer 0 / relay chain (Substrate, Nominated Proof-of-Stake), with ~~6 seconds (relay chain) block times and grandpa finality, typically within a few blocks once two-thirds of validators attest finality. That cadence sets how frequently new-block subscriptions fire.

Frequently asked questions

See the full Polkadot RPC page for chain details, or the WebSocket docs for the complete method list.