Guide to Gemini Enterprise and A2UI integration

The article exposes a core tension in agent-based interfaces: agents return text, but users need interactive UI for tasks like date picking, multi-select, or maps. Multi-turn slot filling burns turns and patience, while sending raw HTML risks XSS and visual drift. Developers needed a safe, expressive way to transmit UI from agents to chat surfaces.

A2UI solves this by defining an open protocol where agents emit declarative JSON payloads describing a component tree (Card, Text, Button, ChoicePicker, etc.) plus a separate data model. The payload is declarative, not executable, so clients only render from a pre-approved catalog, eliminating injection risks. It is also streaming-friendly and framework-agnostic. Inside Gemini Enterprise (GE), the A2UI renderer is built-in: developers just register their A2A agent, and GE handles rendering and interaction serialization. The same agent response can also render in Lit, Flutter, or a custom frontend.

The key takeaway for builders is that you can add rich, interactive UI to agents without choosing a frontend framework upfront—your A2A endpoint runs anywhere, and GE provides the shell and renderer. The reference implementation (ADK backend on Cloud Run) demonstrates a restaurant-finder agent that uses a ChoicePicker for restaurants and a live GoogleMap component, with API keys injected server-side. The fastest path is to clone the repo, run make register-gemini-enterprise, and start customizing.