eth_subscribe on Arbitrum Nova

Everything below was measured on 2026-10-13 by calling eth_subscribe on Arbitrum Nova through the same endpoint customers use, and is re-measured weekly.

What eth_subscribe does

Opens a subscription over WebSocket: newHeads pushes each new block header, logs pushes matching events, and newPendingTransactions pushes mempool transaction hashes where the node exposes them. It replaces polling, and it only works over WebSocket, not HTTP.

Example request

wscat -c "wss://rpc.swiftnodes.io/ws/arbitrum-nova?key=YOUR_API_KEY"
> {"jsonrpc":"2.0","id":1,"method":"eth_subscribe","params":["newHeads"]}

import { createPublicClient, webSocket } from "viem";

const client = createPublicClient({
  transport: webSocket("wss://rpc.swiftnodes.io/ws/arbitrum-nova?key=YOUR_API_KEY", { reconnect: true }),
});

const unwatch = client.watchBlocks({
  onBlock: (block) => console.log(block.number, block.hash),
});

// Events from one contract, pushed as they are mined
client.watchContractEvent({ address: token, abi: erc20Abi, eventName: "Transfer", onLogs: (logs) => console.log(logs) });

Other methods on Arbitrum Nova

• eth_blockNumberSupported
• eth_chainIdSupported
• eth_getBalanceSupported
• eth_getBlockByNumberSupported
• eth_getTransactionByHashSupported
• eth_getTransactionReceiptSupported
• eth_callSupported
• eth_estimateGasSupported
• eth_gasPriceSupported
• eth_maxPriorityFeePerGasSupported
• eth_sendRawTransactionSupported
• eth_getTransactionCountSupported
• eth_getCodeSupported
• eth_getLogsSupported
• eth_getBlockReceiptsSupported
• eth_feeHistorySupported
• eth_getProofSupported
• eth_createAccessListSupported
• debug_traceCallSupported
• trace_blockNot available
• trace_transactionNot available

eth_subscribe on other chains

• Ethereum
• Base
• Arbitrum
• Optimism
• Polygon
• BNB Smart Chain
• Avalanche
• Sonic
• Linea
• Scroll
• zkSync Era
• Blast
• Mantle
• Gnosis
• Celo
• Berachain
• Monad
• Unichain
• Kaia
• PulseChain
• World Chain
• Ronin
• Abstract
• ApeChain
• MegaETH
• Fantom
• Lisk
• Hemi
• X Layer
• BOB
• Plasma
• Fraxtal
• Zora
• Story
• Soneium
• Sei
• Hyperliquid
• Taiko
• Morph
• Ink
• Katana
• Ethereum Classic
• opBNB
• Mode
• Flare
• Core
• Chiliz
• Telos EVM
• Tempo
• Cronos
• Manta Pacific
• Shibarium
• Boba Network
• Immutable zkEVM

Frequently asked questions