Network1 CU

eth_chainId on Soneium

Returns the chain's EIP-155 chain ID as a hex string. Wallets and libraries call it to confirm they're talking to the expected network.

This is the EIP-155 id used for replay-protected signing — libraries check it on connect, and a mismatch is the usual cause of 'wrong network' errors. It's distinct from net_version (network id); prefer chainId in new code.

Soneium endpoint (public — no key)

https://rpc.nodeflare.app/soneium/public

Method

eth_chainId

Cost

1 CU

Chain ID

1868

Block time

~2 s

Finality

~2 s soft · L1-final ~13 min

Network on Soneium

Chain ID 1868 (0x74c) — Soneium mainnet by Sony Block Solutions, part of the Superchain. Minato (1946) is the testnet.

Parameters

None.

cURL

curl https://rpc.nodeflare.app/soneium/public \
  -X POST \
  -H 'content-type: application/json' \
  -d '{"jsonrpc":"2.0","method":"eth_chainId","params":[],"id":1}'

ethers.js

import { ethers } from 'ethers';

const provider = new ethers.JsonRpcProvider(
  'https://rpc.nodeflare.app/soneium/public'
);

const result = await provider.send('eth_chainId', []);

Try it live

Runs the example above against the public Soneium endpoint — straight from your browser.

eth_chainId on Soneium — FAQ

How do I call eth_chainId on Soneium?

POST a JSON-RPC 2.0 request with "method": "eth_chainId" to NodeFlare's Soneium endpoint at https://rpc.nodeflare.app/soneium/public. No API key is required for the public endpoint.

What does eth_chainId cost on the free tier?

eth_chainId is weighted at 1 compute unit per call. The free tier includes 2,000,000 CU/month, so that is roughly 2,000,000 eth_chainId calls per month — no credit card.

Is eth_chainId available on the public Soneium endpoint?

Yes. eth_chainId works on the public Soneium endpoint (https://rpc.nodeflare.app/soneium/public) with no API key, rate-limited per IP. A free key adds higher limits and a dedicated path.

Anything Soneium-specific to know when using eth_chainId?

Chain ID 1868 (0x74c) — Soneium mainnet by Sony Block Solutions, part of the Superchain. Minato (1946) is the testnet.

Call eth_chainId on Soneium with a free key

2,000,000 compute units/month, heavy methods unlocked, every chain included. No credit card.

Get your free API key →