Etherscan

Use the Etherscan API v2 to access data across over 50 supported chains, including Linea, with a single API key.

To get started, create an account on Etherscan, and then head to the API key page and generate a new key.

warning

Although you can use the same API key across multiple chains, you can only make requests to one chain at a time.

From here, you can use the API key in any request, defining the chains you want to use it with:

async function main() {
  // query ETH balances on Ethereum Mainnet and Linea

  const chains = [1, 59144];

  for (const chain of chains) {
    const query = await fetch(`https://api.etherscan.io/v2/api
           ?chainid=${chain}
           &module=account
           &action=balance
           &address=INSERT_ADDRESS
           &tag=latest&apikey=INSERT_API_KEY`);

    const response = await query.json();

    const balance = response.result;
    console.log(balance);
  }
}

main();

For full details of how to use the Etherscan API v2, see the documentation.