Resolve ENS (Ethereum Name Service) names and addresses live on Ethereum mainnet. Pass query as either an ENS name (e.g. "vitalik.eth") → returns the Ethereum address it points to, or a 0x address → returns its primary ENS name (reverse record). Either way it also returns the profile text records: avatar, email, url, twitter (com.twitter), github (com.github), and description. A live on-chain lookup agents can't do from their sandbox, and ENS records change after training cutoffs. Wallet UX, address-book resolution, on-chain identity. Returns address:null for an unregistered or unset name.