DNS (A/SRV) & WHOIS vs AID & DNS-AID
Classic DNS A/AAAA/SRV records & domain WHOIS is the classic web primitive built for human browsers and pre-integrated services (Resolve a domain name to an IP address or mail/service host andport), whereas Agent Identity and Discovery (AID) and its step 1 (Discover) peers provide the machine-native agentic surface (/.well-known/agent) so autonomous agents can answer: "Given a domain, where is the agent and which protocol should I speak, with cryptographic proof the endpoint controls the matching key?" Across the agenticweb.wiki conformance panel, Agent Identity and Discovery is shipping (multi-implementation in production).
How DNS (A/SRV) & WHOIS compares to AID & DNS-AID at step 1 (Discover): why the classic primitive breaks for software agents, and how sites deploy both together.
| Dimension | Classic DNS A/AAAA/SRV records & domain WHOIS Classic web | Agent Identity and Discovery AID Agentic web |
|---|---|---|
| Primary consumer | Human driving a web browser or pre-integrated developer code | Autonomous software agent, coding harness, or AI search/RAG crawler |
| Lifecycle step | Classic web baseline for step 1 (Discover) | 1 Discover: What is here, and where? |
| Core question answered | Resolve a domain name to an IP address or mail/service host andport. | Given a domain, where is the agent and which protocol should I speak, with cryptographic proof the endpoint controls the matching key? |
| Wire format & entrypoint | DNS A / AAAA / SRV / TXT records | DNS record at /.well-known/agent |
| Failure mode for agents | Classic DNS tells a client which IP address answers for example.com, but not which agent protocol (MCP, A2A, ANP) the domain speaks, where its agent endpoint URI lives, or which public key signs its agent assertions. | Solved natively: Agent Identity & Discovery (AID) answers "given a domain, where is the agent and which protocol should I speak?" using a single DNS TXT record published at the fixed base name _agent.<domain>. |
| Governance & status | Established IETF / W3C / industry baseline | Agent Community open-source project; editor listed as 'Agent Community'; no formal standards body, though the spec discusses composing with IETF-track work (RFC 9421, RFC 7638, RFC 9728, RFC 8414) — Current normative specification |
| Live adoption (/check/ census) | Universal across the classic web | shipping — multi-implementation in production |
| Primary specification | https://www.rfc-editor.org/rfc/rfc1035 | https://raw.githubusercontent.com/agentcommunity/agent-identity-discovery/main/packages/docs/specification.md |
Why DNS (A/SRV) & WHOIS breaks when the caller is an agent
Classic DNS tells a client which IP address answers for example.com, but not which agent protocol (MCP, A2A, ANP) the domain speaks, where its agent endpoint URI lives, or which public key signs its agent assertions.
When to use which (and how they work together)
- Keep Classic DNS A/AAAA/SRV records & domain WHOIS: Every standard internet connection resolving hostnames to IP addresses.
- Add Agent Identity and Discovery (AID): You want zero-HTTP-roundtrip discovery of a domain's agent endpoint, supported protocol (mcp, a2a), and public key via an _agent.<domain> DNS TXT/SVCB record (AID, DNS-AID, or MCP DNS Discovery).
All agentic web standards replacing or extending DNS (A/SRV) & WHOIS
- Agent Identity and Discovery (AID) — shipping: Given a domain, where is the agent and which protocol should I speak, with cryptographic proof the endpoint controls the matching key?
- DNS for AI Discovery (DNS-AID) — prototype: Given a domain, where is its agent endpoint, what protocol does it speak, and how can that be verified via DNSSEC/DANE?
- Discovery of Model Context Protocol Servers via DNS TXT Records — none found: How can a client discover an MCP server's endpoint, the operating organisation's identity, and a signed ~handle identity envelope using DNS TXT records under a domain?
- Agent Name Service v2 (ANS) — none found: What domain-anchored identity belongs to an autonomous agent, and at what assurance tier can that identity be trusted?
- Agent Directory Service (ADS) — shipping · 1/574 probed origins: Given a required skill, which agents provide it, where are they, and how can I fetch a verifiable, content-addressed record describing them?
- Open Agentic Schema Framework (OASF) — shipping: How can an agent's skills, domains, deployment modules and identity be described using a shared, versioned taxonomy so registries can classify and filter it consistently?