Network1 CU

eth_chainId on HyperEVM

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.

HyperEVM endpoint (public — no key)

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

Method

eth_chainId

Cost

1 CU

Chain ID

999

Block time

~1 s (small blocks)

Finality

~1 s

Network on HyperEVM

Chain ID 999 (0x3e7) — HyperEVM mainnet, one of the few chains where public RPC options are still scarce. HyperCore itself is not EVM and has no JSON-RPC.

Parameters

None.

cURL

curl https://rpc.nodeflare.app/hl/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/hl/public'
);

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

Try it live

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

eth_chainId on HyperEVM — FAQ

How do I call eth_chainId on HyperEVM?

POST a JSON-RPC 2.0 request with "method": "eth_chainId" to NodeFlare's HyperEVM endpoint at https://rpc.nodeflare.app/hl/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 HyperEVM endpoint?

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

Anything HyperEVM-specific to know when using eth_chainId?

Chain ID 999 (0x3e7) — HyperEVM mainnet, one of the few chains where public RPC options are still scarce. HyperCore itself is not EVM and has no JSON-RPC.

Call eth_chainId on HyperEVM with a free key

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

Get your free API key →