Google announced A2UI 1.0 on its developer blog on 11 November. Today’s AI agents mostly answer with long text, the company said. That is a poor way to compare three products, for example, or to edit and approve a detailed plan.

The agent describes the screen, the app draws it

A2UI (Agent-to-User Interface) is an open protocol and a set of libraries. Instead of writing UI code, the agent sends JSON messages that specify a screen’s components and the data bound to them. The app’s renderer converts these messages into the app’s own components. No WebView or HTML view is needed, the project’s GitHub page says.

The agent can use only components that the app developer has registered, and messages are validated against a schema. Google also claims that A2UI binds data on the server, so sensitive values do not reach the model.

Version 1.0 adds bidirectional function calls. In Google’s example, a picker for a flight or other booking checks availability on the spot. Accessibility support and extensions for additional metadata are also new. The Munder Difflin blog reported that the 1.0 specification drops theme colours, so styling comes from the target platform’s own theme.

Jetpack Compose and Gemini still support version 0.9.1

Renderers exist for React, Angular and Lit on the web, Flutter for mobile, web and desktop, and SwiftUI on iOS. The Android Jetpack Compose renderer still supports version 0.9.1; Google said 1.0 support is coming soon. Gemini, too, supports version 0.9.1 for now.

Agent SDKs are available for Python, TypeScript and Dart. They generate a skill and prompts for the model, validate the model’s response and convert it into protocol messages. The web and Flutter renderers also work in MCP Apps, an MCP extension for showing interactive screens inside an AI assistant. As a result, A2UI screens can be shown in Claude and Gemini, for example, Google said.

Google said Atlassian, Alation, Bloomberg and ByteDance are already building on A2UI. Atlassian is bringing it to Jira. Alation shows metric cards and charts built with A2UI in Claude. ByteDance’s Lynx renderer supports version 0.9 and is moving to 1.0. The details about these companies come from Google, and the SD Times report repeats Google’s blog.

On 12 November, the repository’s GitHub releases included no release or tag named 1.0, Munder Difflin reported. The repository has moved to a2ui-project/a2ui and is licensed under Apache 2.0.

A2UI is free, open-source software. Documentation and a quick-start guide are at a2ui.org. For developers upgrading from version 0.9, Google provides a guide that covers the changes.