Google Releases A2UI to Standardize Agent-Generated Interfaces
Open protocol lets AI build forms, cards, and dashboards without executing code on clients
Google has published A2UI, an open-source standard that gives AI agents a shared vocabulary for generating user interfaces. The project, released December 15 under Apache 2.0, addresses a growing problem: how do remote agents create interactive UI elements without introducing security risks?
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. Instead of shipping HTML or executable JavaScript, an agent sends structured data that describes what components it wants. The receiving app handles the rendering using its own pre-approved widget catalog, limiting what an agent can actually display.
The internal format uses an updateable, flat representation of components that is optimized for LLMs, which supports streaming and incremental updates. That matters for real-time interactions. Users can watch interfaces assemble progressively rather than waiting for complete responses.
The specification ships at version 0.8 and is already running in production, according to Google. Google's internal mini-app platform Opal and Gemini Enterprise run on the protocol too. Flutter's GenUI SDK uses A2UI under the hood. CopilotKit integrated from day one via AG UI compatibility.
The roadmap is ambitious: adding official support for React, Jetpack Compose, iOS (SwiftUI), and more. React is slated for Q1 2026, with native mobile renderers following in Q2. A v1.0 specification is targeted for Q4 2026.
The Bottom Line: Google's betting that agents need a common way to send UIs across trust boundaries, and it's building the plumbing before the market fragments further.
QUICK FACTS
- Version: 0.8 (public preview), Apache 2.0 license
- Current renderers: Flutter, Angular, Web Components (Lit)
- [GitHub](https://github.com/google/A2UI |) stars: 4,400+ as of late December 2025
- React renderer: planned Q1 2026
- v1.0 target: Q4 2026
