Optimistic BNB Smart Chain(opBNB)

opBNB API Reference for efficient interaction with opBNB nodes, enabling scalable, low-cost transactions and fast finality through Layer 2 solutions on the BSC blockchain.

opBNB is a high-performance, EVM-compatible Layer 2 scaling solution for BNB Smart Chain (BSC), built on the OP Stack — the open-source rollup framework developed by the team behind Optimism. Launched in August 2023 by the BNB Chain core team, opBNB uses optimistic rollup technology to inherit BSC's security while offering sub-second block times, 4,000+ TPS throughput, and median transaction fees below $0.005. The network is fully compatible with the Ethereum JSON-RPC specification, allowing developers to port any EVM-based dApp with minimal changes.

Key Features

• OP Stack Architecture: Built on the same battle-tested optimistic rollup framework as Optimism and Base, ensuring tooling compatibility and a familiar developer experience

• Sub-Second Block Times: ~1 second L2 block production for near-instant transaction confirmations, ideal for gaming, micropayments, and high-frequency dApps

• High Throughput: 4,000+ TPS capacity with 100 MB block size — among the highest-throughput EVM chains in production

• Ultra-Low Fees: Median fees below $0.005 per transaction, with BNB Greenfield integration on the roadmap to reduce costs by an additional 5–10×

• Native Token (BNB): Gas paid in BNB (18 decimals), bridged 1:1 from BSC — no separate gas token to manage

• Full EVM Compatibility: Standard Ethereum JSON-RPC method set; deploy Solidity, Vyper, or any EVM bytecode without modification

• BSC Settlement: Settles transaction data to BNB Smart Chain as L1, inheriting BSC's validator security model

• DeFi & Gaming Focus: Optimized for high-frequency, low-value transactions — already home to 90+ dApps spanning DeFi, on-chain gaming, and SocialFi

• Optimistic Rollup Security: Fraud-proof window with 7-day challenge period; users retain L1-level security guarantees

• Ecosystem Tooling: First-class support for Hardhat, Foundry, Truffle, ethers.js, viem, and web3.py through the standard OP Stack toolchain

TECHNICAL DISCLAIMER: AUTHORITATIVE JSON-RPC SPECIFICATION

GetBlock’s opBNB API reference documentation is provided exclusively for informational purposes and to optimize the developer experience. The canonical and normative specification for the Ethereum JSON-RPC API is maintained by the Ethereum community and published at ethereum.org/en/developers/docs/apis/json-rpc/. For opBNB-specific protocol details, consensus parameters, and ecosystem tooling, consult the official documentation at docs.bnbchain.org/bnb-opbnb/.

Network Information

Property	Value
Network Name	opBNB Mainnet
Chain ID	204
Native Currency	BNB
Decimals	18
Block Time	~1 second
Consensus	Optimistic Rollup on OP Stack
Settlement Layer	BNB Smart Chain (BSC, Chain ID 56)
Smart Contract VM	EVM (Ethereum Virtual Machine)
EVM Compatible	Yes (fully compatible)
Address Format	Ethereum-style (0x…, 20 bytes)
Block Explorer	opbnbscan.com

Base URL

Frankfurt, Germany

https://go.getblock.io/<ACCESS-TOKEN>/

All opBNB JSON-RPC methods are called by sending a POST request to the base URL with a standard JSON-RPC 2.0 body. There is no separate /jsonRPC path or REST GET form — the access token in the URL path handles authentication.

Supported Networks

Network	JSON-RPC	WSS	Frankfurt, Germany	New York, USA	Singapore, Singapore
Mainnet	✅	✅	✅	✅	✅
Testnet	✅	✅	✅	✅	✅

Quickstart

In this section, you will learn how to make your first call with either:

• Axios (JavaScript / Node.js)

• Python (Requests library)

Before you begin, you must have already installed npm or yarn on your local machine (for the Axios example) or Python and pip (for the Python example).

JavaScript (Axios)

1

Setup project

Create and initialize a new project:

mkdir opbnb-api-quickstart
cd opbnb-api-quickstart
npm init --yes

2

Install Axios

npm install axios

3

Create file

Create a new file named index.js. This is where you will make your first call.

4

Set ES module type

Set the ES module "type": "module" in your package.json.

5

Add code

Add the following code to index.js:

index.js

import axios from 'axios';

const data = JSON.stringify({
    "jsonrpc": "2.0",
    "method": "eth_blockNumber",
    "params": [],
    "id": "getblock.io"
});

const config = {
    method: 'post',
    url: 'https://go.getblock.io/<ACCESS-TOKEN>/',
    headers: {
        'Content-Type': 'application/json'
    },
    data: data
};

axios(config)
    .then(response => console.log(JSON.stringify(response.data, null, 2)))
    .catch(error => console.log(error));

Replace <ACCESS-TOKEN> with your actual access token from GetBlock.

6

Run the script

node index.js

Expected output (example):

{
    "jsonrpc": "2.0",
    "id": "getblock.io",
    "result": "0x893e5fa"
}

The result field is the latest block number in hexadecimal. Convert it to decimal to read the block height.

Python (Requests)

Available API Methods

opBNB exposes the full standard Ethereum JSON-RPC method set. All methods are POST-only and called against the base URL above.

Block & Chain Information

Method	Description
eth_blockNumber	Returns the current latest block number
eth_chainId	Returns the chain ID (0xcc = 204 for opBNB mainnet)
eth_getBlockByNumber	Returns block information by block number
eth_getBlockByHash	Returns block information by block hash
eth_getBlockTransactionCountByNumber	Returns the number of transactions in a block by block number
eth_getBlockTransactionCountByHash	Returns the number of transactions in a block by block hash
eth_getBlockReceipts	Returns all transaction receipts for a given block
eth_syncing	Returns sync status or false if node is fully synced

Account & State

Method	Description
eth_getBalance	Returns the BNB balance of an account (in wei)
eth_getCode	Returns the contract bytecode at a given address
eth_getStorageAt	Returns the value at a specific storage slot
eth_getProof	Returns the Merkle proof for an account and optional storage keys
eth_getTransactionCount	Returns the transaction count (nonce) for an account

Transactions

Method	Description
eth_sendRawTransaction	Broadcasts a signed transaction
eth_getTransactionByHash	Returns a transaction by its hash
eth_getTransactionByBlockHashAndIndex	Returns a transaction by block hash and index
eth_getTransactionByBlockNumberAndIndex	Returns a transaction by block number and index
eth_getTransactionReceipt	Returns the receipt for a transaction by hash
eth_call	Executes a read-only call against contract state
eth_estimateGas	Estimates gas required for a transaction

Gas & Fee Market

Method	Description
eth_gasPrice	Returns the current gas price
eth_maxPriorityFeePerGas	Returns the suggested max priority fee per gas (EIP-1559)
eth_feeHistory	Returns historical base fees and priority fees

Logs & Filters

Method	Description
eth_getLogs	Returns logs matching a given filter
eth_newFilter	Creates a new log filter
eth_newBlockFilter	Creates a filter that fires on new blocks
eth_newPendingTransactionFilter	Creates a filter that fires on new pending transactions
eth_getFilterChanges	Polls a filter for new events since the last poll
eth_getFilterLogs	Returns all logs matching a filter
eth_uninstallFilter	Uninstalls a filter

WebSocket Subscriptions

Method	Description
eth_subscribe	Subscribes to events (newHeads, logs, newPendingTransactions)
eth_unsubscribe	Cancels an existing subscription

Network & Client Info

Method	Description
net_version	Returns the network ID (204 for opBNB mainnet)
net_listening	Returns true if the client is actively listening for connections
net_peerCount	Returns the number of peers connected to the node
web3_clientVersion	Returns the client software version
web3_sha3	Returns the Keccak-256 hash of the given data

Support

For technical support and questions:

• Support Email: [e-mail]

See Also

• Official opBNB Documentation

• Ethereum JSON-RPC Specification

• OP Stack Documentation

• opBNBScan Block Explorer

• opBNB on Chainlist

• Ethers.js Documentation

• Viem Documentation

• Hardhat Documentation