net_version on Optimism
Returns the network ID as a decimal string. Largely superseded by eth_chainId but still queried by older tooling.
The legacy network id as a decimal string; for most chains it equals the chain id, but not always. Kept for old tooling — new code should read eth_chainId instead.
Optimism endpoint (public — no key)
https://rpc.nodeflare.app/op/publicMethod
net_version
Cost
1 CU
Chain ID
10
Block time
~2 s
Finality
~2 s soft · L1-final ~13 min
Network on Optimism
Chain ID 10 (0xa) — OP Mainnet. The Superchain shares the OP Stack but every member (Base, Zora, Mode…) is its own chain ID and RPC.
Parameters
None.cURL
curl https://rpc.nodeflare.app/op/public \
-X POST \
-H 'content-type: application/json' \
-d '{"jsonrpc":"2.0","method":"net_version","params":[],"id":1}'ethers.js
import { ethers } from 'ethers';
const provider = new ethers.JsonRpcProvider(
'https://rpc.nodeflare.app/op/public'
);
const result = await provider.send('net_version', []);Try it live
Runs the example above against the public Optimism endpoint — straight from your browser.
net_version on Optimism — FAQ
How do I call net_version on Optimism?
POST a JSON-RPC 2.0 request with "method": "net_version" to NodeFlare's Optimism endpoint at https://rpc.nodeflare.app/op/public. No API key is required for the public endpoint.
What does net_version cost on the free tier?
net_version is weighted at 1 compute unit per call. The free tier includes 2,000,000 CU/month, so that is roughly 2,000,000 net_version calls per month — no credit card.
Is net_version available on the public Optimism endpoint?
Yes. net_version works on the public Optimism endpoint (https://rpc.nodeflare.app/op/public) with no API key, rate-limited per IP. A free key adds higher limits and a dedicated path.
Anything Optimism-specific to know when using net_version?
Chain ID 10 (0xa) — OP Mainnet. The Superchain shares the OP Stack but every member (Base, Zora, Mode…) is its own chain ID and RPC.
Call net_version on Optimism with a free key
2,000,000 compute units/month, heavy methods unlocked, every chain included. No credit card.
Get your free API key →net_version on other chains