Transactions2 CU

eth_getTransactionCount on Optimism

Returns the number of transactions sent from an address — i.e. the next nonce to use. Use the "pending" tag to account for in-flight transactions.

The latest tag counts only mined txs; pending includes in-flight ones — always use pending to pick the next nonce or you'll collide with your own unconfirmed transactions.

Optimism endpoint (public — no key)

https://rpc.nodeflare.app/op/public

Method

eth_getTransactionCount

Cost

2 CU

Chain ID

10

Block time

~2 s

Finality

~2 s soft · L1-final ~13 min

Transactions on Optimism

As the OP Stack pioneer, Optimism transactions carry an L1 data fee on top of L2 execution. Read the receipt's l1Fee fields for the true total cost.

Parameters

[address, blockNumber|tag]

cURL

curl https://rpc.nodeflare.app/op/public \
  -X POST \
  -H 'content-type: application/json' \
  -d '{"jsonrpc":"2.0","method":"eth_getTransactionCount","params":["0x0b2c639c533813f4aa9d7837caf62653d097ff85", "latest"],"id":1}'

The example targets the USDC contract on Optimism — you can run it as-is.

ethers.js

import { ethers } from 'ethers';

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

const result = await provider.send('eth_getTransactionCount', ["0x0b2c639c533813f4aa9d7837caf62653d097ff85", "latest"]);

Try it live

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

eth_getTransactionCount on Optimism — FAQ

How do I call eth_getTransactionCount on Optimism?

POST a JSON-RPC 2.0 request with "method": "eth_getTransactionCount" to NodeFlare's Optimism endpoint at https://rpc.nodeflare.app/op/public. No API key is required for the public endpoint.

What does eth_getTransactionCount cost on the free tier?

eth_getTransactionCount is weighted at 2 compute units per call. The free tier includes 2,000,000 CU/month, so that is roughly 1,000,000 eth_getTransactionCount calls per month — no credit card.

Is eth_getTransactionCount available on the public Optimism endpoint?

Yes. eth_getTransactionCount 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 eth_getTransactionCount?

As the OP Stack pioneer, Optimism transactions carry an L1 data fee on top of L2 execution. Read the receipt's l1Fee fields for the true total cost.

Call eth_getTransactionCount 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 →