eth_chainId on Mode
Everything below was measured on 2026-10-13 by calling eth_chainId on Mode 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.
Mode 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 Mode 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 42010605001"). Unprotected transactions are accepted at the RPC, so replay protection depends on your wallet signing with the chain ID.
| eth_chainId | 0x868b (34,443) |
|---|---|
| net_version | 34443 |
Example request
curl -s https://rpc.swiftnodes.io/rpc/mode?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 Mode before signing
import { createPublicClient, http } from "viem";
const client = createPublicClient({
transport: http("https://rpc.swiftnodes.io/rpc/mode?key=YOUR_API_KEY"),
});
const id = await client.getChainId(); // 34443
if (id !== 34443) throw new Error(`wrong chain: ${id}`);
// Add Mode to a browser wallet
await window.ethereum.request({
method: "wallet_addEthereumChain",
params: [{
chainId: "0x868b",
chainName: "Mode",
nativeCurrency: { name: "ETH", symbol: "ETH", decimals: 18 },
rpcUrls: ["https://rpc.swiftnodes.io/rpc/mode?key=YOUR_API_KEY"],
}],
});Other methods on Mode
- 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_subscribeNot available
- eth_getLogsSupported
- eth_getBlockReceiptsSupported
- eth_feeHistorySupported
- eth_getProofSupported
- eth_createAccessListSupported
- debug_traceCallSupported
- trace_blockSupported
- trace_transactionNot available
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
- Hyperliquid
- Taiko
- Morph
- Ink
- Katana
- Ethereum Classic
- opBNB
- Flare
- Core
- Chiliz
- Telos EVM
- Tempo
- Cronos
- Manta Pacific
- Shibarium
- Boba Network
- Arbitrum Nova
- Immutable zkEVM
Frequently asked questions
Does Mode support eth_chainId?
Yes. eth_chainId answered on the SwiftNodes Mode endpoint when our weekly probe called it through the customer path (2026-10-13).
What is the Mode chain ID?
34443 in decimal, 0x868b in hex, as returned by eth_chainId on 2026-10-13.
How do I add Mode to MetaMask?
Call wallet_addEthereumChain with chainId 0x868b, the native currency ETH with 18 decimals, and your RPC URL; the example on this page has the full object.
Mode endpoints, live block height and WebSocket status are on the Mode RPC page.
One key covers every chain we serve, and SwiftNodes has a free tier.