Agent Protocol
In one line
Agent Protocol is an umbrella term for the standards that let agents talk to each other — or to other systems — in a consistent way, covering attempts like A2A, ACP and AP.
Going deeper
Agent Protocol is not one specific standard. It is an umbrella for attempts like Google's A2A, IBM-backed ACP (Agent Communication Protocol) and the open-source AP (Agent Protocol). All of them are wrestling with the same problem: how do agents from different vendors delegate work to each other and share the result.
The interesting angle for marketers is that any agreed-upon agent interface is effectively a new distribution channel. The 'your shopping agent talks directly to our brand's service agent to check stock and run the payment' story does not exist without something in this layer.
Honest read: the standards landscape is crowded. MCP targets LLM-to-tool, UCP targets agent-to-commerce payments, and Agent Protocol-style standards target agent-to-agent — different layers in theory, but the boundaries are not crisp yet. The shape of the survivors will probably not be clear until late 2026.
Related terms
A2A
A2A (Agent-to-Agent Protocol) is Google-led standard for letting agents from different vendors delegate work to each other and exchange results.
AI AgentMCP
MCP (Model Context Protocol) is the open standard introduced by Anthropic for connecting LLMs to external tools and data sources in a consistent way.
AI AgentUCP
UCP (Universal Commerce Protocol) is the AI-agent payment and checkout protocol Google introduced at NRF 2026, aimed at standardising how agents buy products on a user's behalf.
AI AgentMulti-Agent System
A multi-agent system is several AI agents with different roles cooperating on the same task — used when one agent alone is not enough to solve the problem.
AI AgentOrchestrator Agent
An orchestrator agent is the top-level agent that schedules sub-agents, assigns roles and enforces stop conditions — the control tower of a multi-agent system.
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