Google shares three patterns for combining A2UI and MCP Apps to balance custom UIs with native rendering

Google 分享 A2UI 与 MCP Apps 三种集成架构模式

Google's developer blog posted three architectural patterns for mixing A2UI's declarative native rendering with MCP Apps' iframe-based custom UIs. The key idea: use A2UI's JSON payloads for standard components so the host app renders them natively, and reserve iframes only for complex custom logic—avoiding the visual inconsistency and performance hit of iframe-heavy pages. Pattern 1 lets an MCP server return A2UI JSON directly, bypassing iframes entirely. Patterns 2 and 3 are only mentioned by name in the post; the article doesn't spell out their details or code. A recipe demo shows both panels rendered by A2UI with data fetched from an MCP server. The team is considering an MCP extension to simplify adoption and is collecting feedback on GitHub.

Why it matters: Google's official blog publishes an integration guide for A2UI and MCP Apps with three architecture patterns — directly useful for agent product builders. H and K both hit, but R misses (it's an architecture selection doc, not an identity piece), and it's a single-source post ...