Dept. of CSE, Hong Kong University of Science and Technology Dept. of IE, The Chinese University of Hong Kong This document defines the Agent Name System (ANS), a name registration and resolution protocol for autonomous AI agents in the Agent Network Protocol (ANP) suite. ANS maps agent:// URIs to network-layer peer identifiers, providing the binding between human- readable agent names and the cryptographic peer identities used by the Agent Internet Protocol (AIP) for datagram delivery. ANS defines a Name Record format, four AITP method names for name operations (ans.register, ans.resolve, ans.unregister, ans.lookup), a multi-layer resolution algorithm, and two dissemination mechanisms (GossipSub announcements and DHT storage). ANS supports three addressing modes — unicast, anycast, and channel — over a single URI syntax. ANS is intentionally a narrow name-binding layer: it maps names to peers and tags, but defers capability description to the Agent Description Protocol (ADP), reputation and ranking to companion protocols, and economic anti-spam mechanisms to deployment profiles.