What a Base address holds: the ETH balance read from the chain, every ERC-20 with its balance, market price and USD value, and a USD total - spam tokens imitating real ones are flagged and left out of the total, unpriced tokens listed but not counted. Send {} for the paying wallet. Pay-per-call via x402. An empty body is answered for the wallet that pays (the payment's signer); send {"address":"0x…"} for any other address.