eth_chainId - Optimism RPC Method
Get the chain ID for Optimism. Essential for transaction signing and network verification.
Returns the chain ID used for transaction signing on Optimism.
Why Optimism? Build on the heart of the Superchain powering 60%+ of Ethereum L2 transactions with $6B+ TVL with OP Stack modularity, Superchain interoperability, 17M+ daily transactions across 33 chains, and 20% of tokens for public goods.
Use Cases
The eth_chainId method is essential for:
- Transaction signing - Ensure transactions are signed for the correct network
- Network verification - Confirm connection to the expected chain
- Multi-chain apps - Handle different networks programmatically
- Wallet integration - Validate network before transactions
Code Examples
Related Methods
net_version- Get network versioneth_syncing- Check sync status
trace_transaction
Get traces for a specific transaction on Optimism. Requires archive node for cross-chain DeFi, Superchain-interoperable dApps, and public goods funding recipients.
eth_syncing
Check the sync status of your Optimism node. Returns sync progress or false when fully synced — essential for node health monitoring and dApp reliability.