Agent Name Service (ANS): Architecture & Applications

• ANS is an infrastructure component that facilitates secure, protocol-agnostic agent discovery by mapping names to enriched descriptors including identity, capabilities, and endpoints.
• ANS employs multi-dimensional taxonomy, PKI and decentralized identity, and cryptographic validations to ensure robust trust management and effective threat mitigation.
• ANS’s extensible registry and protocol adapter layer enable seamless cross-vendor interoperability, dynamic context-aware resolution, and scalable multi-agent coordination.

An Agent Name Service (ANS) is an infrastructure component—spanning directory, resolution, and registry functions—designed to support secure, interoperable, and context-aware discovery and communication among autonomous agents in multi-agent systems. ANS systems synthesize the nomenclature, resolution, and trust management principles of traditional services like DNS with innovations in capability-centric indexing, decentralized identity, and security, thereby forming the backbone for agentic ecosystems operating across institutional, technological, and geographic boundaries.

1. Conceptual Foundations and Architectural Principles

The defining principle of ANS is its role as a universal directory for agent discovery, delivering secure, protocol-agnostic, and capability-aware name resolution. Unlike DNS, which statically maps domain names to IP addresses, ANS resolves agent names to structured descriptors encompassing identity, capabilities, endpoints, compliance, and provenance (Huang et al., 15 May 2025, Muscariello et al., 23 Sep 2025, Huang et al., 25 May 2025). Agent names (e.g., a2a://RiskAnalyzer.Financial.AcmeCorp.v2.1.software) encode protocol, function, capability, organizational domain, version, and optional extensions, enabling both human readability and machine interpretability.

Core architectural components include:

• Agent Registry: Distributed database that stores agent profiles, capabilities, and PKI or decentralized identity credentials.
• Certificate Authority (CA) / Registration Authority (RA): Entities responsible for validating identity and issuing X.509 certificates or decentralized identifiers (DIDs).
• Protocol Adapter Layer: Decouples registry implementation from communication standard, enabling multi-protocol registration and lookup (A2A, MCP, ACP, etc.).
• Structured Communication: All interactions (registration, lookup, renewal) employ rigorously defined schema, often in JSON, for validation and interoperability.

This design facilitates a secure, scalable ecosystem for agent registration, renewal, and discovery, with strict validation, version negotiation, and dynamic context adaptation.

2. Naming Schemes, Discovery, and Capability Resolution

ANS naming schemes generalize core concepts from DNS, extending them to encompass agent-specific metadata. A canonical format is:

ANSName = Protocol "://" AgentID "." agentCapability "." Provider ".v" Version "." Extension

Agents register their names alongside descriptors of capabilities, endpoints, protocol extensions, and compliance attestations. Discovery queries are capability-aware, allowing clients to specify protocol, capability domain, provider, version range, and required compliance (e.g., regulatory certifications) (Huang et al., 25 May 2025, Huang et al., 16 Jun 2025). Returned records always include verifiable identity (PKI or DID), endpoint, supported protocol extensions, and signed attestation snippets (such as verifiable credential fragments).

Resolution is tightly coupled with search semantics: advanced ANS variants employ multi-dimensional taxonomy indices (skills, domains, features) mapping capability keys to cryptographically robust content digests (e.g., SHA-256), with subsequent locator mappings for endpoints. This is formalized by:

$$\text{Skill (taxonomy key)} \xrightarrow{\text{Index}} \{\text{CID}_1, \text{CID}_2, \dots \}$$

$$\text{CID} \xrightarrow{\text{Locator}} \{\text{Endpoint}_1, \text{Endpoint}_2, \dots\}$$

Discovery can intersect posting lists across multiple axes:

$$C = P_s \cap \left( \bigcap_{i=1}^m P_{d_i} \right) \cap \left( \bigcap_{j=1}^n P_{f_j} \right)$$

Semantic and hybrid retrieval methods (including keyword matching and RAG) optimize candidate selection (Cui et al., 28 May 2025).

3. Security: Identity Management, Threat Mitigation, and Trust

Security is central to ANS. Most architectures embed PKI for digital signing, certificate chain verification, and challenge–response authentication (Huang et al., 15 May 2025, Huang et al., 25 May 2025, Huang et al., 17 Aug 2025, Huang et al., 16 Jun 2025). Advanced designs leverage DIDs and Verifiable Credentials, enabling decentralized, cryptographically verifiable agent identities and flexible attribute attestation.

Key security features include:

• Digital Signatures: All registration, discovery, and binding operations are signed to ensure authenticity and non-repudiation.
• Certificate Revocation: Revocation lists (CRL, OCSP) promptly disable compromised identities.
• Zero-Knowledge Proofs: Used for selective attribute disclosure during discovery and authorization phases (Huang et al., 25 May 2025, Huang et al., 17 Aug 2025).
• Structured Audit Trails: All registry changes and transactions are logged, with signing and transparency log integration (e.g., via Sigstore) for provenance (Muscariello et al., 23 Sep 2025).
• Layered Threat Mitigation: Referenced security frameworks (e.g., MAESTRO) provide layered defenses against impersonation, registry poisoning, MitM, and DoS. Probability of attack success is formally bounded:

$$P_{success} \leq \varepsilon \cdot \prod_{i=1}^k (1 - P_{detection_i})$$

Behavioral attestation, runtime environment adaptation, and causal chain auditing are extensions for agentic threat detection (Huang et al., 17 Aug 2025).

4. Protocol Interoperability and Extensibility

ANS systems are protocol-agnostic by design. The Protocol Adapter Layer translates registration and discovery between standards including A2A, ACP, MCP, with extensibility for emergent protocols (Huang et al., 15 May 2025, Huang et al., 16 Jun 2025, Muscariello et al., 23 Sep 2025). This facilitates:

• Cross-vendor Service Discovery: Agents can locate and invoke services registered across technological boundaries using standardized metadata and protocol fields.
• Backward/Forward Compatibility: Protocol extension mechanisms (e.g., protocolExtension = <version, extensions, compatibility>) enable evolution without breaking existing workflows.
• Schema-driven APIs: The Open Agentic Schema Framework supports the introduction of new agent modalities (LLM prompt agents, code generators) via additive schema extensions (Muscariello et al., 23 Sep 2025).

The multi-layered registry and adapter model allows ANS to integrate with legacy systems while supporting dynamic discovery, negotiation, and runtime coordination.

5. Context-Aware and Adaptive Resolution

Modern ANS frameworks incorporate dynamic, context-aware resolution engines that select endpoints or communication channels based on task, location, system load, agent capability, and security state (Zinky et al., 5 Aug 2025). Agents advertise their capabilities and deployment constraints via Agent Fact cards. Resolution algorithms aggregate context parameters, negotiate trust/QoS/resource constraints, and return optimized endpoints tailored for each requester—often using recursive lookup through hierarchical name servers.

Adaptive resolution is modeled as an optimization problem:

$\min_{x \in \mathcal{X}} f(x \mid c, q, r)$

where $x$ is the endpoint choice, $\mathcal{X}$ is the set of possible placements, $c$ is context, $q$ is QoS, and $r$ is resource specification.

This approach supports scalable, robust communication for heterogeneous and distributed agentic environments.

6. Operational Integration and Practical Applications

ANS underpins a wide spectrum of agentic multi-agent system applications:

• Dynamic Web Service Coordination: Agents cooperate or compete for service invocation via operational ontologies and standardized protocols (0906.3769).
• Cross-Realm Interoperability: Name-to-name primitives allow seamless mobility and interaction across network realms and legacy protocol boundaries (Melazzi et al., 2013).
• Autonomous Collaboration and Orchestration: MAS architectures integrate ANS for runtime discovery, coordination, and self-organization of agent workflows, exemplified in mathematical reasoning, code generation, and RPA tasks (Zhu et al., 13 May 2025, Cui et al., 28 May 2025).
• Document Translation and Secure Capability Negotiation: 10-step protocols leverage ANS for candidate pre-screening, capability attestation, binding agreements, and auditability in high-compliance environments (Huang et al., 16 Jun 2025).
• Root Domain Naming for LLM Agents: Centralized systems offer unified naming, semantic service discovery, access control, and billing across vendor boundaries (Cui et al., 28 May 2025).
• Distributed Agentic Directory Services: Kademlia-based DHT overlays and artifact registries scale ANS functionality to federated, geo-distributed environments; content-addressed storage and cryptographic provenance provide verifiability and resilience (Muscariello et al., 23 Sep 2025).

Applications extend from resilient service computing and autonomous digital transformation to advanced trust management in zero-trust agent webs (Huang et al., 17 Aug 2025, Deng et al., 29 Sep 2025).

7. Future Directions, Trends, and Challenges

Key trends shaping ANS evolution include:

• Decentralization and Federation: From centralized root naming authorities to federated/blockchain-backed architectures for robustness and systemic trust (Cui et al., 28 May 2025, Muscariello et al., 23 Sep 2025).
• Advanced Privacy: Integration of homomorphic encryption, differential privacy, secure multi-party computation, and selective disclosure (ZKP) is anticipated for privacy-preserving discovery and access control (Huang et al., 25 May 2025).
• Scalability and Performance: Strategic caching, proactive replication, and distributed query processing are recommended for high-load, low-latency environments.
• Regulatory Integration and Transparency: Audit trails, agent passports, and regulatory-aware extensions—built upon robust schema and registry mechanisms—will ensure compliance, traceability, and societal alignment (Deng et al., 29 Sep 2025).
• Unified Multi-Agent Service Middleware: ANS is moving from a simple lookup service toward an intelligent, actively reasoning, self-adapting component embedded within full agentic lifecycle orchestration (Deng et al., 29 Sep 2025).

Challenges persist in cross-vendor trust assurance, evolving protocol standards, and dynamic adaptation of governance in rapidly expanding agentic ecosystems.

Summary Table: Core ANS Features Across Architectures

ANS Feature	Traditional DNS/Service Discovery	Next-Gen Agent Name Service (ANS)	Capability-centric Directory Service
Naming Scheme	Hostname → IP	Protocol/Capability/Org/Version/Ext	Skill/Domain/Feature → CID/Endpoint
Security Model	Static PKI, infrequent updates	PKI, DID/VC, runtime verification	Content digest, cryptographic provenance
Discovery Semantics	Endpoint lookup	Capability-aware, context adaptation	Multi-dimensional taxonomy intersection
Extensibility	Rigid formats, slow evolution	Protocol adapters, extension fields	Schema-driven, additive extension
Interoperability	Limited cross-protocol	Protocol-agnostic, cross-vendor	OCI/ORAS, DHT, multi-modal integration

ANS, in its various forms, is the critical infrastructure for resilient, trustworthy, scalable, and interoperable agentic ecosystems, powering next-generation applications in services computing, multi-agent collaboration, and secure autonomous systems.