opBNB - Build on BNB Chain's High-Performance Layer 2

opBNB RPC
With Dwellir, you get access to our global opBNB network which always routes your API requests to the nearest available location, ensuring low latency and the fastest speeds.

Get your API key →

Why Build on opBNB?

opBNB is BNB Chain's Layer 2 solution, designed to offer ultra-low fees and lightning-fast transaction processing. Built on Optimism's OP Stack, opBNB delivers:

⚡ Ultra-High Performance

• Sub-second block times - Experience instant transaction confirmations
• 100x lower fees than BNB Smart Chain mainnet
• 150M gas limit - Massive throughput for complex applications

🛡️ Enterprise-Grade Security

• Backed by BNB Chain - Leverages proven Layer 1 infrastructure
• Optimistic rollup technology - Inherits Ethereum-level security guarantees
• Battle-tested architecture - Built on proven OP Stack foundation

🌐 Thriving Ecosystem

• Native BNB token - No new tokens to manage
• EVM compatibility - Deploy existing contracts seamlessly
• Growing DeFi ecosystem - Access to expanding financial infrastructure

Quick Start with opBNB

Connect to opBNB in seconds with Dwellir's optimized endpoints:

🔗 RPC Endpoints

opBNB Mainnet (Chain ID: 204)Live

https://api-opbnb-mainnet.n.dwellir.com/YOUR_API_KEY

✓ Archive Node✓ Trace API✓ Debug API✓ WebSocket

Quick Connect:

curl -X POST https://api-opbnb-mainnet.n.dwellir.com/YOUR_API_KEY \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","method":"eth_blockNumber","params":[],"id":1}'

Installation & Setup

Ethers.js v6

import { JsonRpcProvider } from 'ethers';

// Connect to opBNB mainnet
const provider = new JsonRpcProvider(
  'https://api-opbnb-mainnet.n.dwellir.com/YOUR_API_KEY'
);

// Get the latest block
const block = await provider.getBlock('latest');
console.log('Latest block:', block.number);

// Query account balance
const balance = await provider.getBalance('0x...');
console.log('Balance:', balance.toString());

Web3.js

const Web3 = require('web3');

// Connect to opBNB mainnet
const web3 = new Web3(
  'https://api-opbnb-mainnet.n.dwellir.com/YOUR_API_KEY'
);

// Get chain ID to verify connection
const chainId = await web3.eth.getChainId();
console.log('Connected to opBNB:', chainId === 204);

// Get gas price for optimal transaction pricing
const gasPrice = await web3.eth.getGasPrice();
console.log('Current gas price:', gasPrice);

Viem

import { createPublicClient, http } from 'viem';
import { opBNB } from 'viem/chains';

// Create opBNB client
const client = createPublicClient({
  chain: opBNB,
  transport: http('https://api-opbnb-mainnet.n.dwellir.com/YOUR_API_KEY'),
});

// Read contract data
const data = await client.readContract({
  address: '0x...',
  abi: contractAbi,
  functionName: 'balanceOf',
  args: ['0x...'],
});

Web3.py

from web3 import Web3

# Connect to opBNB mainnet
w3 = Web3(Web3.HTTPProvider('https://api-opbnb-mainnet.n.dwellir.com/YOUR_API_KEY'))

# Verify connection
print(f"Connected: {w3.is_connected()}")
print(f"Chain ID: {w3.eth.chain_id}")
print(f"Latest block: {w3.eth.block_number}")

# Get account balance
balance = w3.eth.get_balance('0x...')
print(f"Balance: {w3.from_wei(balance, 'ether')} BNB")

Network Information

Chain ID

204

Mainnet

Gas Limit

150M

Per block

Gas Token

BNB

Native token

RPC Standard

Ethereum

JSON-RPC 2.0

JSON-RPC API Reference

opBNB supports the full Ethereum JSON-RPC API specification. Access all standard methods plus Layer 2 optimizations.

Available JSON-RPC Methods

📊 Reading Blockchain Data

Query blocks, transactions, and account states

+

📤 Sending Transactions

Submit and manage transactions

+

📝 Smart Contract Interaction

Call and interact with smart contracts

+

🔧 Node & Network Info

Query node status and network information

+

Ready to build on opBNB's high-performance L2?

Get your API key →

Common Integration Patterns

🔄 Transaction Monitoring

Monitor pending and confirmed transactions efficiently:

// Watch for transaction confirmation
async function waitForTransaction(txHash) {
  const receipt = await provider.waitForTransaction(txHash, 1);
  
  // Check transaction status
  if (receipt.status === 1) {
    console.log('Transaction confirmed:', receipt.transactionHash);
  }
  
  return receipt;
}

💰 Gas Optimization

Optimize gas costs on opBNB Layer 2:

// Get current fee data
const feeData = await provider.getFeeData();

// Estimate gas for transaction
const gasEstimate = await provider.estimateGas({
  to: recipient,
  value: amount,
  data: '0x'
});

// Calculate total cost
const totalCost = gasEstimate * feeData.gasPrice;
console.log(`Transaction cost: ${totalCost} wei`);

🔍 Event Filtering

Efficiently query contract events with pagination:

// Query events with automatic retry and pagination
async function getEvents(contract, eventName, fromBlock = 0) {
  const filter = contract.filters[eventName]();
  const events = [];
  const batchSize = 5000; // opBNB recommended batch size
  
  const currentBlock = await provider.getBlockNumber();
  
  for (let i = fromBlock; i <= currentBlock; i += batchSize) {
    const batch = await contract.queryFilter(
      filter, 
      i, 
      Math.min(i + batchSize - 1, currentBlock)
    );
    events.push(...batch);
  }
  
  return events;
}

Performance Best Practices

1. Batch Requests

Combine multiple RPC calls for optimal performance:

const batch = [
  { method: 'eth_blockNumber', params: [] },
  { method: 'eth_gasPrice', params: [] },
  { method: 'eth_getBalance', params: [address, 'latest'] }
];

const results = await provider.send(batch);

2. Connection Pooling

Reuse provider instances to minimize connection overhead:

// Singleton pattern for provider
class OpBNBProvider {
  static instance = null;
  
  static getInstance() {
    if (!this.instance) {
      this.instance = new JsonRpcProvider(
        'https://api-opbnb-mainnet.n.dwellir.com/YOUR_API_KEY'
      );
    }
    return this.instance;
  }
}

3. Smart Caching

Cache immutable data to reduce API calls:

const cache = new Map();

async function getCachedBlockData(blockNumber) {
  const key = `block_${blockNumber}`;
  
  if (!cache.has(key)) {
    const block = await provider.getBlock(blockNumber);
    cache.set(key, block);
  }
  
  return cache.get(key);
}

Troubleshooting Common Issues

Wrong Chain ID Error

opBNB uses specific chain IDs for mainnet and testnet:

// Always verify chain ID matches expected network
const chainId = await provider.send('eth_chainId', []);

if (chainId === '0xcc') {
  console.log('Connected to opBNB Mainnet (204)');
} else if (chainId === '0x15eb') {
  console.log('Connected to opBNB Testnet (5611)');
} else {
  throw new Error(`Unexpected chain ID: ${chainId}`);
}

Transaction Underpriced Error

opBNB uses dynamic gas pricing:

// Get current fee data
const feeData = await provider.getFeeData();

const tx = {
  to: recipient,
  value: amount,
  maxFeePerGas: feeData.maxFeePerGas,
  maxPriorityFeePerGas: feeData.maxPriorityFeePerGas,
  gasLimit: 21000n
};

Rate Limit Exceeded

Implement exponential backoff for resilient applications:

async function callWithRetry(fn, maxRetries = 3) {
  for (let i = 0; i < maxRetries; i++) {
    try {
      return await fn();
    } catch (error) {
      if (error.code === 429 && i < maxRetries - 1) {
        await new Promise(r => setTimeout(r, 2 ** i * 1000));
      } else {
        throw error;
      }
    }
  }
}

FAQs

Q: What's the difference between opBNB and BNB Smart Chain? A: opBNB is a Layer 2 scaling solution built on top of BNB Smart Chain, offering much lower fees and faster transactions while maintaining full EVM compatibility.

Q: Can I use the same wallet for opBNB and BSC? A: Yes, any Ethereum-compatible wallet works with opBNB. Simply add the opBNB network configuration to your wallet.

Q: How do I bridge assets to opBNB? A: Use the official opBNB Bridge at https://opbnb-bridge.bnbchain.org to transfer assets between BNB Smart Chain and opBNB.

Smoke Tests

Quick Connection Tests

Mainnet Connection:

curl -X POST https://api-opbnb-mainnet.n.dwellir.com/YOUR_API_KEY \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","method":"eth_blockNumber","params":[],"id":1}'

Testnet Connection:

curl -X POST https://api-opbnb-testnet.n.dwellir.com/YOUR_API_KEY \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","method":"eth_blockNumber","params":[],"id":1}'

Ethers.js Verification:

import { JsonRpcProvider } from 'ethers';

const provider = new JsonRpcProvider('https://api-opbnb-mainnet.n.dwellir.com/YOUR_API_KEY');

// Test connection
const blockNumber = await provider.getBlockNumber();
const network = await provider.getNetwork();

console.log(`Block: ${blockNumber}, Chain ID: ${network.chainId}`);

Web3.py Verification:

from web3 import Web3

w3 = Web3(Web3.HTTPProvider('https://api-opbnb-mainnet.n.dwellir.com/YOUR_API_KEY'))

print(f"Connected: {w3.is_connected()}")
print(f"Chain ID: {w3.eth.chain_id}")
print(f"Block Number: {w3.eth.block_number}")

Migration Guide

From BNB Smart Chain to opBNB

Migrating from BSC to opBNB requires minimal code changes:

// Before (BSC)
const provider = new JsonRpcProvider('https://bsc-dataseed.bnbchain.org');

// After (opBNB)
const provider = new JsonRpcProvider(
  'https://api-opbnb-mainnet.n.dwellir.com/YOUR_API_KEY'
);

// ✅ Smart contracts work identically
// ✅ Same tooling and libraries
// ⚠️ Different chain ID (204 vs 56)
// ⚠️ Separate block numbers
// ⚠️ Much lower gas fees

Resources & Tools

Official Resources

• opBNB Documentation
• opBNB Bridge
• opBNB Block Explorer

Developer Tools

• Hardhat Configuration
• Remix IDE Integration
• Truffle Support

Need Help?

• 📧 Email: support@dwellir.com
• 📚 Docs: You're here!
• 🎯 Dashboard: dashboard.dwellir.com

---

Start building on opBNB with Dwellir's enterprise-grade RPC infrastructure. Get your API key →