Logs & events20 CUFree key required

eth_newFilter on Optimism

Creates a server-side log filter and returns its id, which you then poll with eth_getFilterChanges. Stateful; needs a free API key.

The filter id is pinned to one node's memory, so it doesn't work reliably behind a multi-node load balancer without sticky routing. For durable indexing, prefer repeated eth_getLogs with your own block cursor.

Optimism endpoint (keyed — free)

https://rpc.nodeflare.app/op/v1/YOUR_KEY

Method

eth_newFilter

Cost

20 CU

Chain ID

10

Block time

~2 s

Finality

~2 s soft · L1-final ~13 min

Logs & events on Optimism

Optimism's log volume is moderate compared to Base — wider eth_getLogs windows are practical, but the 75 CU weight per call still rewards tight filters.

Parameters

[{ fromBlock, toBlock, address, topics[] }]

cURL

curl https://rpc.nodeflare.app/op/v1/YOUR_KEY \
  -X POST \
  -H 'content-type: application/json' \
  -d '{"jsonrpc":"2.0","method":"eth_newFilter","params":[{"fromBlock": "latest", "toBlock": "latest"}],"id":1}'

ethers.js

import { ethers } from 'ethers';

const provider = new ethers.JsonRpcProvider(
  'https://rpc.nodeflare.app/op/v1/YOUR_KEY'
);

const result = await provider.send('eth_newFilter', [{"fromBlock": "latest", "toBlock": "latest"}]);

Try it live

Runs the example above against the public Optimism endpoint — straight from your browser.

eth_newFilter on Optimism — FAQ

How do I call eth_newFilter on Optimism?

POST a JSON-RPC 2.0 request with "method": "eth_newFilter" to NodeFlare's Optimism endpoint at https://rpc.nodeflare.app/op/v1/YOUR_KEY. This method requires a free API key — it is not available on the public endpoint.

What does eth_newFilter cost on the free tier?

eth_newFilter is weighted at 20 compute units per call. The free tier includes 2,000,000 CU/month, so that is roughly 100,000 eth_newFilter calls per month — no credit card.

Is eth_newFilter available on the public Optimism endpoint?

No. eth_newFilter is a heavy method and requires a free API key. The public no-key endpoint serves standard read methods; create a free key to unlock eth_newFilter, eth_getLogs, trace_* and debug_*.

Anything Optimism-specific to know when using eth_newFilter?

Optimism's log volume is moderate compared to Base — wider eth_getLogs windows are practical, but the 75 CU weight per call still rewards tight filters.

Call eth_newFilter 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 →