Guide to AI Agent Protocols: MCP, A2A, ACP & More

As AI agents become more prevalent, a variety of protocols have been developed to streamline and standardize their interactions with systems, users, and each other. These protocols, which include the Model Context Protocol (MCP), Agent-to-Agent Protocol (A2A), Agent Communication Platform (ACP), Agent Network Protocol (ANP), and Agent Payment Protocol (AP2), serve distinct functions such as resource access, multi-agent communication, internet-wide collaboration, and secure financial transactions. MCP focuses on integrating agents with external resources, A2A facilitates direct peer-to-peer communication among agents, ACP employs a client-server architecture for agent interaction, ANP enables decentralized web-based communication, and AP2 allows secure financial transactions through cryptographic mandates. These protocols are designed to complement each other and are used across various layers of communication, networking, and tool access in AI systems. As agentic AI continues to evolve, modular design and interoperability of protocols are crucial for developing adaptable systems that can thrive in complex environments.