It’s not MCP Vs A2A, it’s A2A Vs ACP.

I’ve been quiet and waiting to comment about the new A2A Google protocol because the amount of disinformation I’ve been seeing here, made me doubt even about my own understanding of it. So I think it is time to explain and clarify things.

To start, I keep seeing people compare MCP to A2A as if they’re in the same weight class. They’re not. The real fight is A2A vs ACP, and it’s just getting started.

🔹 MCP (Model Context Protocol) is a plug‑and‑play pipe that lets one model call tools & data sources. Think “ChatGPT Plugins, but open‑standard.”

🔹 A2A (Agent‑to‑Agent) is Google’s vision of a global agent mesh: publish an Agent Card, discover others, then handshake over HTTPS or gRPC. No orchestrator required.

🔹 ACP (Agent Communication Protocol) is IBM’s counter‑punch: inherit MCP’s JSON‑RPC plumbing, add an orchestration layer, and let a “lead” agent farm out tasks to specialists.

🤜🤛 Protocol wars 2.0: VHS vs Betamax vibes, but for AI agents. MCP isn’t even in that ring, it’s the HDMI cable the contenders still need.

💡 My bet? We’ll end up with “MCP inside, A2A/ACP outside.” MCP feeds the tools; whichever agent‑mesh standard wins will choreograph the specialists.

❗ So please, let’s stop comparing apples to screwdrivers. The real conversation is A2A vs ACP, and how (or whether) they converge.

Why MCP ≠ A2A❓

MCP’s remit is one AI model talking to external tools or data via JSON‑RPC; it was never designed for agent‑to‑agent discovery or delegation.

Why A2A vs ACP matters❓

Google’s A2A starts with peer discovery (public Agent Cards) and assumes a flat, many‑to‑many network.

IBM’s ACP keeps MCP’s request/response backbone but layers in orchestration verbs so one “hub” agent can split work and re‑assemble answers.

Both chase identical use‑cases (multi‑agent workflows), so they’re natural competitors.

How they might coexist❓

Teams already on MCP can adopt ACP internally and expose the whole cluster as a single A2A‑compliant agent card—bridging both worlds until the standards shake out.

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