opBNB RPC Endpoints

Dwellir provides opBNB RPC endpoints at https://api-opbnb-mainnet.n.dwellir.com/<your-api-key> for mainnet (Chain ID 204) and https://api-opbnb-testnet.n.dwellir.com/<your-api-key> for testnet (Chain ID 5611). Replace <your-api-key> with the key from your Dwellir dashboard.

Yes. WebSocket endpoints are available at wss://api-opbnb-mainnet.n.dwellir.com/<your-api-key> for mainnet and wss://api-opbnb-testnet.n.dwellir.com/<your-api-key> for testnet. Use WebSockets for real-time subscriptions like eth_subscribe for new blocks, pending transactions, and log events.

Dwellir's opBNB mainnet endpoints run full nodes that retain recent blockchain state. The testnet endpoints run archive nodes with full historical state access. For mainnet archive requirements, contact our team about dedicated archive node options.

1. Sign up at dwellir.com and retrieve your API key from the dashboard. 2. Replace your current RPC URL (e.g., https://opbnb-mainnet-rpc.bnbchain.org) with https://api-opbnb-mainnet.n.dwellir.com/<your-api-key>. 3. For WebSocket connections, use wss://api-opbnb-mainnet.n.dwellir.com/<your-api-key>. The API is fully compatible with standard Ethereum JSON-RPC methods.

opBNB Mainnet uses Chain ID 204 with BNB as the native token and ~1 second block times. opBNB Testnet uses Chain ID 5611 with tBNB. Built on the OP Stack, opBNB is an Optimistic Rollup that settles to BNB Smart Chain (BSC) with up to 4,000+ TPS and sub-cent fees. Block explorers: opbnbscan.com (mainnet) and testnet.opbnbscan.com (testnet).

Dwellir's opBNB endpoints are fully compatible with standard EVM tooling including Web3.js, ethers.js, viem, and Web3.py. Development frameworks like Hardhat, Foundry, and Truffle work seamlessly. As an OP Stack chain, opBNB shares the same tooling ecosystem as Optimism and Base. Simply configure your provider with the Dwellir RPC URL and your API key.

opBNB fees are dramatically lower than BSC—targeting under $0.001 per transfer vs. BSC's variable fees. opBNB costs have two components: 1) L2 execution fee: Covers computation and storage on opBNB (very low due to high throughput), 2) L1 posting cost: Shared cost for batching transaction data to BSC for verification. The L1 component is amortized across many transactions in a batch, making individual transactions cheap. With ~1 second blocks and 4,000+ TPS capacity, opBNB is optimized for high-frequency, low-value transactions like gaming and micropayments.

Currently, opBNB posts transaction data as calldata to BSC (its L1). The BNB Chain roadmap includes integration with BNB Greenfield for cheaper data availability—similar to how Ethereum L2s use EIP-4844 blobs. Planned upgrades aim to reduce fees by 5-10x through: 1) Moving data to Greenfield's decentralized storage, 2) Improved compression, 3) Higher L2 gas limits (doubled to 200M gas/second in 2024). These changes happen at the protocol level; your application code won't need modifications to benefit.