An open protocol governed by a W3C Community Group that defines how AI agents identify themselves, describe their services, and discover peers across decentralized networks. ANP focuses on the cross-network discovery layer of the agentic stack and is designed to interoperate with but remain independent of MCP and A2A.
Every ANP agent MUST have a primary identifier that is a Decentralized Identifier conforming to the W3C DID 1.0 specification
DIDs let any party verify which keys control an agent without relying on a registrar, which is what makes cross-network discovery possible in the first place
An agent's DID MUST be resolvable to a DID Document through its declared DID method, and the DID Document MUST include at least one verification method the agent can use to sign its own descriptions
A DID that cannot be resolved is indistinguishable from noise; the verification method is how remote agents check that discovery payloads are authentic
A description fragment listing one service, the transport protocol it speaks, and a cryptographic proof pointing at the signing key in the agent's DID Document
ANP defines discovery as following a chain from a DID to a description document to a set of services, with fallback mechanisms when direct resolution fails
When direct DID resolution is unavailable, consumers SHOULD fall back to a trusted ANP registry and cache the resolved description with a short TTL
Network partitions and slow DID methods should not hard-fail discovery; a registry with an explicit TTL keeps availability high without silently stale data
An intermediary relaying ANP traffic MUST preserve the original sender's DID and signature on forwarded payloads; it MUST NOT re-sign messages as itself
Re-signing destroys the end-to-end identity chain and lets intermediaries silently impersonate any sender that passes through them
Intermediaries MUST NOT rewrite service endpoints, DIDs, or descriptions of traffic they pass through
A routing layer that silently rewrites identities turns the discovery network into a blind trust chain, which is the exact problem ANP sets out to solve
Verifiers SHOULD re-resolve the DID Document whenever a cached verification method fails, to accommodate legitimate key rotation before failing the verification hard
Agents will rotate keys on a routine basis; treating the first cache miss as a hard failure makes the network fragile for healthy lifecycle events
w3c-cg
Discovery Layer