WebSocket Subscriptions

Rome EVM endpoints support Ethereum WebSocket subscriptions (eth_subscribe / eth_unsubscribe) over wss://. Connect to the same host as the HTTPS RPC, with the wss:// scheme:

wss://<chain>.testnet.romeprotocol.xyz/

This is what ethers / viem WebSocketProvider use under the hood, so .on('block'), contract.on(event), and viem's watchEvent / watchBlocks work out of the box.

Subscription types

Type	Fires on	Use for
newHeads	each new block	block tickers, refreshing balances/nonces, per-block bots, indexers
logs	matching events (by address / topics)	reacting to your contract's events, relayers/bridges, trading bots
newPendingTransactions	—	accepted but never emits (Rome has no public mempool)

ethers (v6)

import { ethers } from "ethers";

const provider = new ethers.WebSocketProvider(
  "wss://martius-i.testnet.romeprotocol.xyz/"
);

// newHeads
provider.on("block", (blockNumber) => {
  console.log("new block", blockNumber);
});

// logs — react to a contract event
const contract = new ethers.Contract(address, abi, provider);
contract.on("Transfer", (from, to, value) => {
  console.log("Transfer", from, to, value.toString());
});

viem

import { createPublicClient, webSocket } from "viem";

const client = createPublicClient({
  transport: webSocket("wss://martius-i.testnet.romeprotocol.xyz/"),
});

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

client.watchEvent({
  address,
  onLogs: (logs) => console.log(logs),
});

Raw JSON-RPC

→ {"jsonrpc":"2.0","id":1,"method":"eth_subscribe","params":["newHeads"]}
← {"jsonrpc":"2.0","id":1,"result":"0x…"}                       // subscription id
← {"jsonrpc":"2.0","method":"eth_subscription","params":{"subscription":"0x…","result":{…block…}}}

For logs, pass a filter object as the second param:

{"jsonrpc":"2.0","id":1,"method":"eth_subscribe","params":["logs",{"address":"0x…","topics":["0x…"]}]}

Notes

• Subscriptions push updates as new blocks are produced (latency is on the order of a block time).

• For long-lived connections, handle reconnects in your client — standard for any WebSocket RPC.