a2ui

# A2UI

**Build delightful, fast, reliable agentic experiences**

A2UI (Agent-to-User Interface) is an open-source generative UI framework,
complete with a protocol optimized for streaming dynamic user interfaces at
low latency, native renderers for web and mobile frameworks, and agent SDKs
in several popular languages. With A2UI, your agents can communicate with
your users using natively rendered widgets, in addition to text.

<img src="docs/public/assets/a2ui_gallery_examples.png" alt="Gallery of A2UI components" height="400">

_Examples of UI compositions that A2UI can express._

## Quick links

- [Main website](https://a2ui.org).
- Try it in your browser using [A2UI Composer](https://a2ui-project.github.io/composer/).
- [Supported renderers](https://a2ui.org/reference/renderers/).
- [Supported agents](https://a2ui.org/reference/agents/).
- [Protocol specification](https://a2ui.org/specification/v1.0-a2ui/).

## Introduction

Large language models (LLMs) and decision models (e.g.
[Jev](https://docs.typesafe.ai/)) excel at creating text and code and at making
fast decisions on top of raw structured data (e.g. JSON). A2UI gives these
models a specialized vocabulary for expressing user interfaces.

A2UI expresses UI using _data_, not code. A schema for the data exchanged
between the agent and the renderer enforces strict capability boundaries for
the agent, keeping agent-generated experiences safe and aligned with the
business requirements of your application. A _core library_, a _native
framework adapter_, and a _catalog of components_ provide access to native
components and form the building blocks that the agent _composes_ into a final
user experience, making the result expressive and high-performance.

## When to use A2UI

Use A2UI when any of the following apply to your application:

- Parts of your application are agent- and/or server-driven. By design, A2UI
  supports remote rendering.
- You want the UI to be composed dynamically, tailored to the user's immediate
  need. Instead of making your users navigate through multiple screens to solve
  their problems, have the agent build the right flow of UI that guides users
  directly to solutions.
- You need the highest performance and visual fidelity. A2UI renders UI using
  the framework of your choice, typically one that the host app itself is
  written in. WebViews or HTML are not required.
- The same agent streams UI to multiple platforms or frameworks, such as
  Flutter, React, SwiftUI, and Jetpack Compose. A2UI helps keep the user
  experience compatible and consistent across all screens.
- The agent is remote, third-party, or operates across a trust boundary. For
  example, the agent must not be able to handle certain kinds of data (credit
  card/account numbers, PII, financial data). A2UI helps enforce the trust
  boundary and protect your app's critical functionality from hallucinations
  using a strict schema, and by expressing UI using validated data rather than
  executable code.