Generative UI Specs
Generative UI Specifications
Several recently released specifications enable agents to return generative UI, increasing the power and flexibility of the Agent-to-User conversation.
A2UI, MCP Apps, and Open-JSON-UI are all generative UI specifications that allow agents to respond to users not only with text but also with dynamic UI components. CopilotKit now provides universal support for all major Generative UI specifications.
| Specification | Origin / Maintainer | Purpose |
|---|---|---|
| A2UI | A declarative, LLM-friendly Generative UI spec. JSONL-based and streaming, designed for platform-agnostic rendering. | |
| Open-JSON-UI | OpenAI | An open standardization of OpenAI's internal declarative Generative UI schema. |
| MCP Apps | MCP Ecosystem | Iframe-based Generative UI extending MCP, enabling servers to return interactive UI components. |
AG-UI vs Generative UI Specs
Despite the naming similarities, AG-UI is not a generative UI specification — it's a User Interaction protocol that provides the bi-directional runtime connection between the agent and the application.
AG-UI natively supports all of the above generative UI specs and allows developers to define their own custom generative UI standards as well.
Learn More
Explore each specification in detail:
- A2UI - Google's declarative Generative UI spec
- Open-JSON-UI - OpenAI's open Generative UI standard
- MCP Apps - Iframe-based Generative UI extending MCP
Or learn about related protocols:
- AG-UI Protocol - The user interaction protocol that supports all these specs
- Generative UI Guide - Build with Generative UI in CopilotKit