eth_chainId on Boba Network
Everything below was measured on 2026-10-13 by calling eth_chainId on Boba Network 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.
Boba Network 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 Boba Network 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 | 0x120 (288) |
|---|---|
| net_version | 288 |
Example request
curl -s https://rpc.swiftnodes.io/rpc/boba?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 Boba Network before signing
import { createPublicClient, http } from "viem";
const client = createPublicClient({
transport: http("https://rpc.swiftnodes.io/rpc/boba?key=YOUR_API_KEY"),
});
const id = await client.getChainId(); // 288
if (id !== 288) throw new Error(`wrong chain: ${id}`);
// Add Boba Network to a browser wallet
await window.ethereum.request({
method: "wallet_addEthereumChain",
params: [{
chainId: "0x120",
chainName: "Boba Network",
nativeCurrency: { name: "ETH", symbol: "ETH", decimals: 18 },
rpcUrls: ["https://rpc.swiftnodes.io/rpc/boba?key=YOUR_API_KEY"],
}],
});Other methods on Boba Network
- 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_blockNot available
- 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
- Mode
- Flare
- Core
- Chiliz
- Telos EVM
- Tempo
- Cronos
- Manta Pacific
- Shibarium
- Arbitrum Nova
- Immutable zkEVM
Frequently asked questions
Does Boba Network support eth_chainId?
Yes. eth_chainId answered on the SwiftNodes Boba Network endpoint when our weekly probe called it through the customer path (2026-10-13).
What is the Boba Network chain ID?
288 in decimal, 0x120 in hex, as returned by eth_chainId on 2026-10-13.
How do I add Boba Network to MetaMask?
Call wallet_addEthereumChain with chainId 0x120, the native currency ETH with 18 decimals, and your RPC URL; the example on this page has the full object.
Boba Network endpoints, live block height and WebSocket status are on the Boba Network RPC page.
One key covers every chain we serve, and SwiftNodes has a free tier.