A2A - AG2

A2UIAgent: Rich UI from Your AG2 Agents

Your AG2 agent can reason, call tools, and stream text. But what if it could also generate a full UI — cards, forms, buttons, images — from a single prompt?

A2UIAgent is a new reference agent in AG2 that produces rich, interactive user interfaces using the A2UI protocol. Instead of returning plain text, the agent generates structured JSON that client-side renderers transform into native UI components. The same agent serves web, mobile, and desktop clients — all through standard protocols.

In this post, we'll walk through what A2UIAgent does, how it works under the hood, and how to build a working demo that generates marketing preview cards served over A2A.

A2A Protocol Support in AG2 v0.10

AG2 v0.10 introduces native support for the Agent2Agent (A2A) Protocol, enabling agents to communicate across different processes, frameworks, and languages through a standardized interface.

This article walks through implementing A2A in AG2, with a focus on practical patterns for building distributed agent systems.

What is A2A?

A2A is a JSON-RPC 2.0 protocol over HTTP(S) for agent-to-agent communication. It provides a framework-agnostic interface that allows agents built with different tools (AG2, LangGraph, CrewAI, Semantic Kernel, Pydantic AI, etc.) to communicate without custom integration code.

The protocol handles: