Optimism
Optimism API is available on Web3 API platform.
Optimism is a fast, stable, and scalable L2 blockchain built by Ethereum developers, for Ethereum developers. Built as a minimal extension to existing Ethereum software, Optimism’s EVM-equivalent architecture scales your Ethereum apps without surprises. If it works on Ethereum, it works on Optimism at a fraction of the cost.
In order for your Web3 application to interact with Optimism — either by reading blockchain data or sending transactions to the network — it must connect to an Optimism node. Developers interact with the blockchain using the methods provided by the API.
The API interaction follows the JSON-RPC which is a stateless, light-weight remote procedure call (RPC) protocol. It defines several data structures and the rules around their processing. It is transport agnostic in that the concepts can be used within the same process, over sockets, over HTTP, or in other message-passing environments. It uses JSON (RFC 4627) as data format.
For Optimism, we support the following methods:
EVM JSON-RPC methods
web3_clientVersion— returns the current client version.web3_sha3— returns Keccak-256 (not the standardized SHA3-256) of the given data.net_version— returns the current network ID.net_listening— returns true if client is actively listening for network connections.eth_protocolversion— returns the current Ethereum protocol version.eth_syncing— returns data on the sync status or false.eth_gasPrice— returns the current price per gas in wei.eth_accounts— returns a list of addresses owned by client.eth_blockNumber— returns the number of most recent block.eth_getBalance— returns the balance of the account specified by address.eth_getStorageAt— returns the value from a storage position at an address specified.eth_getTransactionCount— returns the number of transactions sent from an address.eth_getBlockTransactionCountByHash— returns the number of transactions in a block specified by block hash.eth_getBlockTransactionCountByNumber— returns the number of transactions in the block specified by number.eth_getUncleCountByBlockHash— returns the number of uncles in a block specified by block hash.eth_getUncleCountByBlockNumber— returns the number of uncles in a block specified by block number.eth_getCode— returns code at an address specified.eth_sendRawTransaction— creates a new message call transaction or a contract creation for signed transactions.eth_call— executes a new message call immediately without creating a transaction on the blockchain.eth_estimateGas— generates and returns an estimate of how much gas is necessary to allow the transaction to complete.eth_getBlockByHash— returns information for the block specified by block hash.eth_getBlockByNumber— returns information for the block specified by block number.eth_getTransactionByHash— returns information on a transaction specified by transaction hash.eth_getTransactionByBlockHashAndIndex— returns information on a transaction specified by block hash and transaction index position.eth_getTransactionByBlockNumberAndIndex— returns information on a transaction by block number and transaction index position.eth_getTransactionReceipt— returns the receipt of a transaction by transaction hash.eth_getUncleByBlockHashAndIndex— returns information about an uncle of a block by hash and uncle index position.eth_getUncleByBlockNumberAndIndex— returns information about an uncle of a block by number and uncle index position.eth_getLogs— returns logs matching the parameters specified.
Flashblocks methods
Flashblocks is a core Optimism feature that provides preconfirmation of the upcoming block's transaction ordering (~250 milliseconds) before the full block is sealed (~2 seconds).
This enables ultra-fast transaction feedback, allowing applications to deliver instant and interactive user experiences. Flashblocks are particularly valuable for high-frequency trading platforms, real-time games, live dashboards, and other latency-sensitive use cases where even a brief delay feels disruptive.
Flashblocks are integrated directly into Optimism’s block production process, therefore developers gain the advantages of low-latency feedback without compromising security or reliability. The result is a seamless foundation for applications that demand speed, responsiveness, and trust.
The following RPC methods can return Flashblocks specific data:
eth_getBlockByNumber— withpending, retrieves the latest Flashblock.eth_getTransactionReceipt— retrieves receipts for preconfirmed transactions.eth_getBalance— withpending, retrieves the address balance in the latest Flashblock.eth_getTransactionCount— withpending, retrieves the address nonce in the latest Flashblock.eth_getTransactionByHash— retrieves preconfirmed transactions by hash.
Methods
web3, net, eth
web3_clientVersionweb3_sha3net_versionnet_listeningeth_protocolVersioneth_syncingeth_gasPriceeth_accountseth_blockNumbereth_getBalanceeth_getStorageAteth_getTransactionCounteth_getBlockTransactionCountByHasheth_getBlockTransactionCountByNumbereth_getUncleCountByBlockHasheth_getUncleCountByBlockNumbereth_getCodeeth_sendRawTransactioneth_calleth_estimateGaseth_getBlockByHasheth_getBlockByNumbereth_getTransactionByHasheth_getTransactionByBlockHashAndIndexeth_getTransactionByBlockNumberAndIndexeth_getTransactionReceipt