Native coin balance for any address on Ethereum, Base, Arbitrum, Optimism, Polygon, or BNB Chain, plus ERC-20 token balances (pass up to 10 contract addresses). Reads public chain state over JSON-RPC; no API keys. Amounts given raw and human-formatted. POST a JSON body like: {"chain":"base","address":"0xB86F95EF5FA904318Ea9Df3b59AdCe099b478fC4"}

Payment Options