A2UI

A2UI: Agent-to-User Interface

A2UI is an open-source project, complete with a format optimized for representing updatable agent-generated UIs and an initial set of renderers, that allows agents to generate or populate rich user interfaces.

*A gallery of A2UI rendered cards, showing a variety of UI compositions that A2UI can achieve.*

⚠️ Status: Early stage public preview

**Note:** A2UI is currently in **v0.8 (Public Preview)**. The specification and implementations are functional but are still evolving. We are opening the project to foster collaboration, gather feedback, and solicit contributions (e.g., on client renderers). Expect changes.

Summary

Generative AI excels at creating text and code, but agents can struggle to present rich, interactive interfaces to users, especially when those agents are remote or running across trust boundaries.

**A2UI** is an open standard and set of libraries that allows agents to "speak UI." Agents send a declarative JSON format describing the *intent* of the UI. The client application then renders this using its own native component library (Flutter, Angular, Lit, etc.).

This approach ensures that agent-generated UIs are **safe like data, but expressive like code**.

High-level philosophy

A2UI was designed to address the specific challenges of interoperable, cross-platform, generative or template-based UI responses from agents.

The project's core philosophies:

• Security first: Running arbitrary code generated by an LLM may present a security risk. A2UI is a declarative data format, not executable code. Your client application maintains a "catalog" of trusted, pre-approved UI components (e.g., Card, Button, TextField), and the agent can only request to render components from that catalog.
• LLM-friendly and incrementally updatable: The UI is represented as a flat list of components with ID references whic