Paper

arXiv:2505.02279 — A Survey of Agent Interoperability Protocols: MCP, ACP, A2A, and ANP

Key Finding

Systematic comparison of the four major agent interoperability protocols: MCP (tool access), ACP (REST-based agent communication), A2A (task delegation with streaming), and ANP (decentralized agent networks). Identifies capability gaps and overlap between protocols, and when to use each.

Applicability to Zeph

• Architecture reference: Zeph implements MCP (client) and A2A (client + server). This survey provides a structured framework for understanding what ANP and ACP would add on top of existing implementations.
• ANP gap: Zeph has no ANP support. Survey likely clarifies when A2A (centralized task delegation) vs ANP (decentralized peer discovery) is appropriate — relevant for agent discovery design.
• ACP vs A2A: The zeph-a2a server uses JSON-RPC 2.0; ACP uses REST. The survey comparison can inform whether ACP support would expand Zeph's interoperability with other agent frameworks (LangGraph, CrewAI, AutoGen).
• Protocol selection guidelines: When adding new agent communication features, use this as the reference for which protocol to target.