eth_chainId on Sei
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.
Sei endpoint (public — no key)
https://rpc.nodeflare.app/sei/publicMethod
eth_chainId
Cost
1 CU
Chain ID
1329
Block time
~0.4 s
Finality
~0.4 s (single-block finality)
Network on Sei
Chain ID 1329 (0x531) — Sei EVM mainnet (pacific-1). The Cosmos-side RPC is a separate, non-EVM interface.
Parameters
None.cURL
curl https://rpc.nodeflare.app/sei/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/sei/public'
);
const result = await provider.send('eth_chainId', []);Try it live
Runs the example above against the public Sei endpoint — straight from your browser.
eth_chainId on Sei — FAQ
How do I call eth_chainId on Sei?
POST a JSON-RPC 2.0 request with "method": "eth_chainId" to NodeFlare's Sei endpoint at https://rpc.nodeflare.app/sei/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 Sei endpoint?
Yes. eth_chainId works on the public Sei endpoint (https://rpc.nodeflare.app/sei/public) with no API key, rate-limited per IP. A free key adds higher limits and a dedicated path.
Anything Sei-specific to know when using eth_chainId?
Chain ID 1329 (0x531) — Sei EVM mainnet (pacific-1). The Cosmos-side RPC is a separate, non-EVM interface.
Call eth_chainId on Sei with a free key
2,000,000 compute units/month, heavy methods unlocked, every chain included. No credit card.
Get your free API key →