🔁WebSocket (WSS) API

Overview

This page describes how the WebSocket (WSS) interface works and how it differs from standard HTTP RPC. Blockchain WebSocket API allows applications to receive blockchain events in real time through persistent subscriptions. The interface supports event channels for new blocks, confirmed transactions, and address-level activity.

What Is WSS

The WebSocket (WSS) interface establishes a persistent bi-directional connection between the client and the node.

How WSS differs from HTTP RPC

• HTTP RPC processes each request independently. The client must poll the node to check for updates.

• WSS maintains a continuous connection and pushes events immediately when they occur.

• WSS is more efficient for applications requiring real-time data and reduces the need for high-frequency polling.

Available event channels

The WSS interface supports subscriptions to:

• new blocks,

• confirmed transactions,

• events for specific addresses.

These channels allow applications to react to on-chain changes with minimal latency.

Use Cases

Non-Custodial Wallets

• Update balances and transaction lists in real time using addr events.

• Notify users when incoming or outgoing transfers are confirmed.

Block Explorers

• Detect new blocks immediately through the block channel.

• Receive confirmed transactions through tx to update block and transaction views.

Web3 Analytics and Monitoring Tools

• Aggregate confirmed transactions in real time using tx.

• Track block production and network activity through block.

Web3 Notification Services

• Trigger alerts on address activity using addr.

• Send user notifications when transactions are confirmed via tx.

How to Access WSS

To access WebSocket (WSS) endpoints, register an account, choose any paid plan, create an API key, and connect to the WSS URLs listed in the documentation.

If the required network is not listed or a specific WSS interface is not yet enabled, you can request its inclusion in the shared plan at [e-mail]. In some cases, support for this interface may already be in progress.

If you need guaranteed access or additional performance immediately, you can request a dedicated node deployment for that network in the dashboard or by contacting [e-mail]. We will provide pricing and deployment time.

Supported Networks

WebSocket (WSS) access is available for the networks listed below.

Ethereum - WSS

WSS RPC

• Endpoint: wss://eth.nownodes.io/wss/{YOUR_API_KEY}

WSS Blockbook

• Endpoint: wss://eth-blockbook.nownodes.io/wss/{YOUR_API_KEY}

WSS Blockbook Sepolia

• Endpoint: wss://ethbook-sepolia.nownodes.io/wss/{YOUR_API_KEY}

Bitcoin - WSS

WSS RPC

• Endpoint: wss://btc.nownodes.io/wss/{YOUR_API_KEY}

WSS Blockbook

• Endpoint: wss://btcbook.nownodes.io/wss/{YOUR_API_KEY}

WSS RPC Testnet

• Endpoint: wss://btc-testnet.nownodes.io/wss/{YOUR_API_KEY}

EthereumPoW - WSS

WSS RPC

• Endpoint: wss://ethw.nownodes.io/wss/{YOUR_API_KEY}

BNB Smart Chain - WSS

WSS RPC

• Endpoint: wss://bsc.nownodes.io/wss/{YOUR_API_KEY}

WSS Blockbook

• Endpoint: wss://bsc-blockbook.nownodes.io/wss/{YOUR_API_KEY}

XRP - WSS

WSS RPC

• Endpoint: wss://xrp.nownodes.io/wss/{YOUR_API_KEY}

EVM WSS RPC

• Endpoint: wss://xrp-evm.nownodes.io/wss/{YOUR_API_KEY}

Cardano - WSS

WSS RPC

• Endpoint: wss://ada-ogmios.nownodes.io/wss/{YOUR_API_KEY}

Solana - WSS

WSS RPC

• Endpoint: wss://sol.nownodes.io/wss/{YOUR_API_KEY}

Dogecoin - WSS

WSS RPC

• Endpoint: wss://doge.nownodes.io/wss/{YOUR_API_KEY}

WSS Blockbook

• Endpoint: wss://dogebook.nownodes.io/wss/{YOUR_API_KEY}

Litecoin - WSS

WSS RPC

• Endpoint: wss://ltc.nownodes.io/wss/{YOUR_API_KEY}

WSS Blockbook

• Endpoint: wss://ltcbook.nownodes.io/wss/{YOUR_API_KEY}

WSS RPC Testnet

• Endpoint: wss://ltc-testnet.nownodes.io/wss/{YOUR_API_KEY}

Base - WSS

WSS RPC

• Endpoint: wss://base.nownodes.io/wss/{YOUR_API_KEY}

WSS Blockbook

• Endpoint: wss://base-blockbook.nownodes.io/wss/{YOUR_API_KEY}

Akash Network - WSS

WSS RPC

• Endpoint: wss://akt.nownodes.io/wss/{YOUR_API_KEY}

zkSync - WSS

WSS RPC

• Endpoint: wss://zksync.nownodes.io/wss/{YOUR_API_KEY}

Polygon - WSS

WSS RPC

• Endpoint: wss://matic.nownodes.io/wss/{YOUR_API_KEY}

WSS Blockbook

• Endpoint: wss://maticbook.nownodes.io/wss/{YOUR_API_KEY}

Avalanche - WSS

WSS RPC

• Endpoint: wss://avax.nownodes.io/wss/{YOUR_API_KEY}

WSS Blockbook

• Endpoint: wss://avax-blockbook.nownodes.io/wss/{YOUR_API_KEY}

Dash - WSS

WSS RPC

• Endpoint: wss://dash.nownodes.io/wss/{YOUR_API_KEY}

Polkadot - WSS

WSS RPC

• Endpoint: wss://dot.nownodes.io/wss/{YOUR_API_KEY}

WSS Asset Hub

• Endpoint: wss://dot-assethub.nownodes.io/wss/{YOUR_API_KEY}

Kusama - WSS

WSS RPC

• Endpoint: wss://ksm.nownodes.io/wss/{YOUR_API_KEY}

WSS Asset Hub

• Endpoint: wss://ksm-assethub.nownodes.io/wss/{YOUR_API_KEY}

ZetaChain - WSS

WSS RPC

• Endpoint: wss://zetachain-tendermint.nownodes.io/wss/{YOUR_API_KEY}

Bitcoin Cash - WSS

WSS RPC

• Endpoint: wss://bch.nownodes.io/wss/{YOUR_API_KEY}

WSS Blockbook

• Endpoint: wss://bchbook.nownodes.io/wss/{YOUR_API_KEY}

Cosmos - WSS

WSS RPC

• Endpoint: wss://atom.nownodes.io/wss/{YOUR_API_KEY}

Celestia - WSS

WSS RPC

• Endpoint: wss://tia.nownodes.io/wss/{YOUR_API_KEY}

Celestia - WSS

WSS RPC

• Endpoint: wss://tia.nownodes.io/wss/{YOUR_API_KEY}

Axelar - WSS

WSS RPC

• Endpoint: wss://axelar.nownodes.io/wss/{YOUR_API_KEY}

Zcash - WSS

WSS RPC

• Endpoint: wss://zec.nownodes.io/wss/{YOUR_API_KEY}

Optimism - WSS

WSS RPC

• Endpoint: wss://optimism.nownodes.io/wss/{YOUR_API_KEY}

WSS Index

• Endpoint: wss://optimism-index.nownodes.io/wss/{YOUR_API_KEY}

Arbitrum - WSS

WSS Blockbook

• Endpoint: wss://arb-blockbook.nownodes.io/wss/{YOUR_API_KEY}

Osmosis - WSS

WSS RPC

• Endpoint: wss://osmo.nownodes.io/wss/{YOUR_API_KEY}

Injective - WSS

WSS RPC

• Endpoint: wss://inj.nownodes.io/wss/{YOUR_API_KEY}

Pulsechain - WSS

WSS RPC

• Endpoint: wss://pulse.nownodes.io/wss/{YOUR_API_KEY}

Qtum - WSS

WSS RPC

• Endpoint: wss://qtum.nownodes.io/wss/{YOUR_API_KEY}

WSS Blockbook

• Endpoint: wss://qtum-blockbook.nownodes.io/wss/{YOUR_API_KEY}

BeraChain - WSS

WSS RPC

• Endpoint: wss://bera.nownodes.io/wss/{YOUR_API_KEY}

Rootstock - WSS

WSS RPC

• Endpoint: wss://rsk.nownodes.io/wss/{YOUR_API_KEY}