eth_chainId on Unichain
Everything below was measured on 2026-10-13 by calling eth_chainId on Unichain 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.
Unichain 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 Unichain 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 63000021001"). Unprotected transactions are accepted at the RPC, so replay protection depends on your wallet signing with the chain ID.
| eth_chainId | 0x82 (130) |
|---|---|
| net_version | 130 |
Example request
curl -s https://rpc.swiftnodes.io/rpc/unichain?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 Unichain before signing
import { createPublicClient, http } from "viem";
const client = createPublicClient({
transport: http("https://rpc.swiftnodes.io/rpc/unichain?key=YOUR_API_KEY"),
});
const id = await client.getChainId(); // 130
if (id !== 130) throw new Error(`wrong chain: ${id}`);
// Add Unichain to a browser wallet
await window.ethereum.request({
method: "wallet_addEthereumChain",
params: [{
chainId: "0x82",
chainName: "Unichain",
nativeCurrency: { name: "ETH", symbol: "ETH", decimals: 18 },
rpcUrls: ["https://rpc.swiftnodes.io/rpc/unichain?key=YOUR_API_KEY"],
}],
});Other methods on Unichain
- 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_getProofSupported
- eth_createAccessListSupported
- 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
- Kaia
- PulseChain
- World Chain
- Ronin
- Abstract
- ApeChain
- MegaETH
- Fantom
- Lisk
- Hemi
- X Layer
- BOB
- Plasma
- Fraxtal
- Zora
- Story
- Soneium
- Sei
- Hyperliquid
- 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 Unichain support eth_chainId?
Yes. eth_chainId answered on the SwiftNodes Unichain endpoint when our weekly probe called it through the customer path (2026-10-13).
What is the Unichain chain ID?
130 in decimal, 0x82 in hex, as returned by eth_chainId on 2026-10-13.
How do I add Unichain to MetaMask?
Call wallet_addEthereumChain with chainId 0x82, the native currency ETH with 18 decimals, and your RPC URL; the example on this page has the full object.
Unichain endpoints, live block height and WebSocket status are on the Unichain RPC page.
One key covers every chain we serve, and SwiftNodes has a free tier.