A2UI: Agent-to-User Interface

A2UI is an open-source project that enables AI agents to generate and populate rich, interactive user interfaces across platforms. It provides a declarative JSON format for UI specifications and initial renderers.

Summary

Generative AI excels at text/code creation but struggles with UI presentation, especially across trust boundaries. A2UI solves this by:

• Declarative JSON Format: Agents send UI intent as structured data
• Client-Side Rendering: Native implementations (Flutter, Angular, Lit, etc.) render safely
• Security First: Pre-approved component catalogs prevent code execution risks
• LLM-Friendly: Incrementally updatable flat component structures
• Framework-Agnostic: Same JSON renders across platforms

Core Philosophy

• Security: Declarative data format, not executable code
• Incremental Updates: Flat component lists with ID references for progressive rendering
• Portability: Abstract descriptions mapped to native widgets
• Flexibility: Registry pattern for custom component implementations

Use Cases

1. Dynamic Data Collection: Context-aware forms (e.g., specialized booking systems)
2. Remote Sub-Agents: Orchestrate specialized agents with UI payloads (e.g., travel booking)
3. Adaptive Workflows: Generate approval dashboards/data visualizations on-demand

Architecture

1. Generation: Agent creates A2UI JSON payload
2. Transport: Send via A2A Protocol/AG UI
3. Resolution: Client renderer parses JSON
4. Rendering: Maps abstract components to native widgets

Getting Started

Prerequisites

• Node.js (web clients)
• Python (agent samples)
• Gemini API key

Restaurant Finder Demo

# Clone & setup
git clone https://github.com/google/A2UI.git
cd A2UI
export GEMINI_API_KEY="your_key"

# Run Agent
cd samples/agent/adk/restaurant_finder
uv run .

# Run Client (new terminal)
cd renderers/markdown/markdown-it && npm install && npm run build
cd ../../web_core && npm install && npm run build
cd ../lit && npm install && npm run build
cd ../../samples/client/lit/shell && npm install && npm run dev

Roadmap

• Spec stabilization (v1.0)
• React, Jetpack Compose, SwiftUI renderers
• REST transport support
• Genkit/LangGraph integrations

License

Apache 2.0

Explore Documentation