RPC method

eth_chainId on Flare

Supported on SwiftNodes

Everything below was measured on 2026-10-13 by calling eth_chainId on Flare 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.

Flare 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 Flare a legacy transaction signed without a chain ID (pre-EIP-155). Its nodes refused it: "only replay-protected (EIP-155) transactions allowed over RPC". Sign with chain ID 14; every mainstream library does this by default.

eth_chainId	0xe (14)
net_version	14

Example request

curl -s https://rpc.swiftnodes.io/rpc/flare?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 Flare before signing
import { createPublicClient, http } from "viem";

const client = createPublicClient({
  transport: http("https://rpc.swiftnodes.io/rpc/flare?key=YOUR_API_KEY"),
});

const id = await client.getChainId(); // 14
if (id !== 14) throw new Error(`wrong chain: ${id}`);

// Add Flare to a browser wallet
await window.ethereum.request({
  method: "wallet_addEthereumChain",
  params: [{
    chainId: "0xe",
    chainName: "Flare",
    nativeCurrency: { name: "FLR", symbol: "FLR", decimals: 18 },
    rpcUrls: ["https://rpc.swiftnodes.io/rpc/flare?key=YOUR_API_KEY"],
  }],
});

Other methods on Flare

eth_chainId on other chains

Frequently asked questions

Does Flare support eth_chainId?

Yes. eth_chainId answered on the SwiftNodes Flare endpoint when our weekly probe called it through the customer path (2026-10-13).

What is the Flare chain ID?

14 in decimal, 0xe in hex, as returned by eth_chainId on 2026-10-13.

How do I add Flare to MetaMask?

Call wallet_addEthereumChain with chainId 0xe, the native currency FLR with 18 decimals, and your RPC URL; the example on this page has the full object.

Flare endpoints, live block height and WebSocket status are on the Flare RPC page.

One key covers every chain we serve, and SwiftNodes has a free tier.