Bidirectional ENS + Basename resolution: POST { name } (e.g. vitalik.eth or jesse.base.eth) to resolve its address, or POST { address } to resolve its primary name (checks both Base basename and Ethereum .eth). Uses the L1 ENS Universal Resolver with ENSIP-19, CCIP-read, which a Base-only RPC cannot do. For AI agents resolving human-readable names to addresses and labeling counterparties before transacting.