Ask HN: Can someone ELI5 how Google's A2A is different from MCP?

1 point·tuyguntn··3 comments

After reading some contents related to Google's new A2A, it still didn't click to me, how is it different from MCP? Can someone please ELI5 with a good example?

In my mind, I am still designing things with MCP. Even the communication between 2 agents can modeled as MCP with some capabilities.

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MCP (Model Context Protocol) is essentially a protocol for tool access. It defines a standard way for large language models to interact with various tools, data, and resources. Simply put, MCP enables AI to use various functionalities, much like how programmers call functions.

A2A (Agent-to-Agent Protocol) focuses on agent collaboration. It establishes ways for intelligent agents to discover, communicate, and cooperate with each other, allowing different AI systems to work together like human teams.

Taken straight from this article:

https://a2aprotocol.ai/blog/a2a-vs-mcp

it still didn't click me.

Let's say I have 2 agents which uses 2 APIs under the hood: - Agent A: uses API A1 and A2 through MCP - Agent B: uses API B1 and B2 through MCP

Assumption here is that, Agent A can't access APIs B1 and B2 but can access Agent B. What if I expose Agent B as an MCP server. Why do I need A2A?

The simple answer is it is Google that alone should make it easy to understand.

They can't monetize a MCP API so they made A2A.

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