Optimism API

Optimism is a Layer-2 scaling solution for Ethereum, aiming to improve transaction throughput and reduce fees by employing optimistic rollups, a technology that enables faster and more cost-effective smart contract execution.

Networks Mainnet
Released 2019
Consensus Optimistic Rollups
Smart contracts Yes
Block time 2 seconds
Smart contract language(s) supported Go, Javascript, Solidity, and Typescript
Get Started with Optimism

Bitcoin
Ethereum
XRP Ledger
Ethereum Classic
Bitcoin Cash
Dash
Litecoin
Dogecoin
Zcash
View all supported

The Optimism API — build without running a node

Access Optimism blockchain data through one unified REST API: transaction and address data, balances, block data, and real-time webhooks for on-chain events — with no Optimism node to run and maintain. Start free and scale as you grow.

Blockchain data

Read Optimism transactions, addresses, balances, UTXOs, and block data through one REST API.

Real-time webhooks

Subscribe to on-chain events — incoming and outgoing transactions, confirmations, and mined blocks.

No node to run

Skip the infrastructure — managed, always-synced access with no node to operate or maintain.

View the API docs Start building free

Building a full wallet? Explore HD Wallets.

Need prices too? See the crypto price API, or run your own Optimism RPC nodes.

The Optimism Blockchain

Optimism blockchain, crafted by Ethereum developers for Ethereum developers, stands as a swift, reliable, and scalable Layer 2 blockchain. Functioning as a streamlined augmentation to current Ethereum software, Optimism architecture mirrors the EVM, ensuring seamless scalability for your Ethereum applications. If a feature operates on Ethereum, it seamlessly translates to OP Mainnet, offering the same functionality at a significantly reduced cost.

Frequently Asked Questions

Which blockchain does Optimism run on?

Optimism settles on Optimism. Tokens live in their own contracts rather than in the account balance, so reading them means calling the token contract; and every transaction needs the account's next nonce, which the same API returns.

What kind of chain is Optimism?

It is an account-model EVM chain — every address has a single balance and a nonce.

Can I test Optimism without spending real funds?

Yes — the same endpoints serve Optimism's Sepolia testnet, so you can build and verify an integration end to end before you touch mainnet.

How do I read Optimism balances and transfers?

Use Address Latest for current state and recent activity — it needs no setup and answers for roughly the last 14 days. For a full history, Address History requires the address to be synced first, which then bills per address per day for as long as it stays synced.

What does reading Optimism data cost?

It depends on the endpoint family rather than on Optimism itself: single-record calls are charged per request, while list endpoints are charged per page returned, and a synced address adds a daily monitoring charge. The pricing calculator has the current per-chain figures.