# Evolution of AI Agent Registry Solutions: Centralized, Enterprise, and Distributed Approaches

arXiv: https://arxiv.org/abs/2508.03095 · HTML: https://mlsanity.com/paper/2508.03095/

## Key facts

- Cited by 4 papers in the map (data through 14 Oct 2026).
- Builds on 5 of its 21 references that are in the map.
- First posted on arXiv 5 Aug 2025.

## Builds on (most cited first, 5 of 5)

- [Trustworthy AI: From Principles to Practices](https://mlsanity.com/paper/2110.01167/) (2021)
- [A survey of agent interoperability protocols: Model Context Protocol (MCP), Agent Communication Protocol (ACP), Agent-to-Agent Protocol (A2A), and Agent Network Protocol (ANP)](https://mlsanity.com/paper/2505.02279/) (2025)
- [Beyond DNS: Unlocking the Internet of AI Agents via the NANDA Index and Verified AgentFacts](https://mlsanity.com/paper/2507.14263/) (2025)
- [Intelligent Zero Trust Architecture for 5G/6G Networks: Principles, Challenges, and the Role of Machine Learning in the context of O-RAN](https://mlsanity.com/paper/2105.01478/) (2021)
- [Upgrade or Switch: Do We Need a Next-Gen Trusted Architecture for the Internet of AI Agents?](https://mlsanity.com/paper/2506.12003/) (2025)

## Built on by (most cited first, 4 of 4)

- [Distributional AGI Safety](https://mlsanity.com/paper/2512.16856/) (2025)
- [The AGNTCY Agent Directory Service: Architecture and Implementation](https://mlsanity.com/paper/2509.18787/) (2025)
- [From Skills to Talent: Organising Heterogeneous Agents as a Real-World Company](https://mlsanity.com/paper/2604.22446/) (2026)
- [Internal APIs Are All You Need: Shadow APIs, Shared Discovery, and the Case Against Browser-First Agent Architectures](https://mlsanity.com/paper/2604.00694/) (2026)

## Abstract (arXiv)

Autonomous AI agents now operate across cloud, enterprise, and decentralized domains, creating demand for registry infrastructures that enable trustworthy discovery, capability negotiation, and identity assurance. We analyze five prominent approaches: (1) MCP Registry (centralized publication of mcp.json descriptors), (2) A2A Agent Cards (decentralized self-describing JSON capability manifests), (3) AGNTCY Agent Directory Service (IPFS Kademlia DHT content routing extended for semantic taxonomy-based content discovery, OCI artifact storage, and Sigstore-backed integrity), (4) Microsoft Entra Agent ID (enterprise SaaS directory with policy and zero-trust integration), and (5) NANDA Index AgentFacts (cryptographically verifiable, privacy-preserving fact model with credentialed assertions). Using four evaluation dimensions: security, authentication, scalability, and maintainability, we surface architectural trade-offs between centralized control, enterprise governance, and distributed resilience. We conclude with design recommendations for an emerging Internet of AI Agents requiring verifiable identity, adaptive discovery flows, and interoperable capability semantics.