eth_chainId on Hyperliquid
Everything below was measured on 2026-10-13 by calling eth_chainId on Hyperliquid through the same endpoint customers use, and is re-measured weekly.
What eth_chainId does
Returns the chain ID (EIP-155) as a hex string. Wallets and libraries check it before signing, and the signature commits to it, so a transaction signed for one chain cannot be replayed on another.
Hyperliquid chain ID, as measured
net_version returns the same number as decimal text. Older tools read net_version; use eth_chainId, which is the value signatures commit to.
We sent Hyperliquid a legacy transaction signed without a chain ID (pre-EIP-155). Its nodes did not reject it for that: the answer was about the empty balance ("insufficient funds for gas * price + value: have 0 want 4688017509001"). Unprotected transactions are accepted at the RPC, so replay protection depends on your wallet signing with the chain ID.
| eth_chainId | 0x3e7 (999) |
|---|---|
| net_version | 999 |
Example request
curl -s https://rpc.swiftnodes.io/rpc/hyperliquid?key=YOUR_API_KEY \
-X POST -H "Content-Type: application/json" \
-d '{"jsonrpc":"2.0","id":1,"method":"eth_chainId","params":[]}'// Check you are on Hyperliquid before signing
import { createPublicClient, http } from "viem";
const client = createPublicClient({
transport: http("https://rpc.swiftnodes.io/rpc/hyperliquid?key=YOUR_API_KEY"),
});
const id = await client.getChainId(); // 999
if (id !== 999) throw new Error(`wrong chain: ${id}`);
// Add Hyperliquid to a browser wallet
await window.ethereum.request({
method: "wallet_addEthereumChain",
params: [{
chainId: "0x3e7",
chainName: "Hyperliquid",
nativeCurrency: { name: "HYPE", symbol: "HYPE", decimals: 18 },
rpcUrls: ["https://rpc.swiftnodes.io/rpc/hyperliquid?key=YOUR_API_KEY"],
}],
});Other methods on Hyperliquid
- eth_blockNumberSupported
- eth_getBalanceSupported
- eth_getBlockByNumberSupported
- eth_getTransactionByHashSupported
- eth_getTransactionReceiptSupported
- eth_callSupported
- eth_estimateGasSupported
- eth_gasPriceSupported
- eth_maxPriorityFeePerGasSupported
- eth_sendRawTransactionSupported
- eth_getTransactionCountSupported
- eth_getCodeSupported
- eth_subscribeSupported
- eth_getLogsSupported
- eth_getBlockReceiptsSupported
- eth_feeHistorySupported
- eth_getProofNot available
- eth_createAccessListNot available
- debug_traceCallSupported
- trace_blockSupported
- trace_transactionSupported
eth_chainId 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
- Taiko
- Morph
- Ink
- Katana
- Ethereum Classic
- opBNB
- Mode
- Flare
- Core
- Chiliz
- Telos EVM
- Tempo
- Cronos
- Manta Pacific
- Shibarium
- Boba Network
- Arbitrum Nova
- Immutable zkEVM
Frequently asked questions
Does Hyperliquid support eth_chainId?
Yes. eth_chainId answered on the SwiftNodes Hyperliquid endpoint when our weekly probe called it through the customer path (2026-10-13).
What is the Hyperliquid chain ID?
999 in decimal, 0x3e7 in hex, as returned by eth_chainId on 2026-10-13.
How do I add Hyperliquid to MetaMask?
Call wallet_addEthereumChain with chainId 0x3e7, the native currency HYPE with 18 decimals, and your RPC URL; the example on this page has the full object.
Hyperliquid endpoints, live block height and WebSocket status are on the Hyperliquid RPC page.
One key covers every chain we serve, and SwiftNodes has a free tier.