--- title: Fast, reliable A2UI, with swappable inference formats description: Google's A2UI protocol adds swappable inference formats to speed up generative UI generation. A2UI Express, a new intermediate format, cuts latency by up to 3x... canonical: https://daily.dev/posts/fast-reliable-a2ui-with-swappable-inference-formats-spimzcepg twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Fast, reliable A2UI, with swappable inference formats | daily.dev og:description: Google's A2UI protocol adds swappable inference formats to speed up generative UI generation. A2UI Express, a new intermediate format, cuts latency by up to 3x... og:url: https://daily.dev/posts/fast-reliable-a2ui-with-swappable-inference-formats-spimzcepg og:image: https://api.daily.dev/og/posts/SpiMZcEpG.png og:image:alt: Fast, reliable A2UI, with swappable inference formats og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Fast, reliable A2UI, with swappable inference formats **[Google Developers](https://daily.dev/sources/googledevs)** · 8 min read · 0 upvotes · 0 comments ## Summary Google's A2UI protocol adds swappable inference formats to speed up generative UI generation. A2UI Express, a new intermediate format, cuts latency by up to 3x and uses up to 3x fewer tokens than Direct JSON. Pairing A2UI with a decision model like Jev, which answers typed questions in 100 to 300 ms, can push speedups to 80x for screens with known layouts. A2UI Express ships in the Python SDK (a2ui-agent-sdk 0.9.0), TypeScript SDK (@a2ui/agent), and Dart SDK (a2ui_agent 0.0.1-wip004). An open-source example, Apparite (jev2ui), built complete screens in 0.8 to 1.7 seconds across 11 test prompts. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### How much faster is A2UI Express than generating Direct JSON for generative UI? A2UI Express reduces latency by up to 3x compared to Direct JSON generation, and requires up to 3x fewer tokens to produce the same UI. Using a decision model like Jev alongside A2UI to make layout decisions can push the speedup up to 80x on screens with a known shape. _Teams optimizing agent UI latency can track protocol updates like this via daily.dev._ ### What is Jev and how does it differ from an LLM for generating UI layouts? Jev, from TypeSafe, is a System One model built for fast structured decisions rather than text or JSON generation. You send it a state plus typed questions (Noul for true/false, Choice for picking from options, Score for rubric scoring), and it returns calibrated probabilities for each, answering many questions per request in roughly 100 to 300 milliseconds. _Developers evaluating decision models versus LLMs for UI logic can follow this comparison on daily.dev._ ### Which SDKs support the A2UI Express inference format and what are the package versions? A2UI Express is available in the Python agent SDK as a2ui-agent-sdk version 0.9.0 on PyPI, the TypeScript agent SDK as @a2ui/agent on npm, and the Dart SDK as a2ui_agent version 0.0.1-wip004 on pub.dev. You select it by passing ExpressFormatFactory() as an argument when creating the generator. _Developers picking an SDK version for agent-driven UI can check package details like these on daily.dev._ ## Similar posts on daily.dev - [A2UI](https://daily.dev/posts/a2ui-fov2gqezm) · Hacker News · 2 upvotes · 0 comments - [A2UI v0.9: The New Standard for Portable, Framework-Agnostic Generative UI](https://daily.dev/posts/a2ui-v0-9-the-new-standard-for-portable-framework-agnostic-generative-ui-s5oyfx03f) · Google Developers · 12 upvotes · 1 comments - [Google Releases A2UI v0.9: Portable, Framework-Agnostic Generative UI](https://daily.dev/posts/google-releases-a2ui-v0-9-portable-framework-agnostic-generative-ui-nhjivffxg) · InfoQ · 1 upvotes · 0 comments - [Guide to Gemini Enterprise and A2UI integration](https://daily.dev/posts/guide-to-gemini-enterprise-and-a2ui-integration-wwj9kzhvm) · Google Cloud · 0 upvotes · 0 comments --- Tags: [#google](https://daily.dev/tags/google), [#ai-inference](https://daily.dev/tags/ai-inference), [#generative-ui](https://daily.dev/tags/generative-ui) [View this post on daily.dev](https://daily.dev/posts/fast-reliable-a2ui-with-swappable-inference-formats-spimzcepg) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Fast, reliable A2UI, with swappable inference formats","url":"https://daily.dev/posts/fast-reliable-a2ui-with-swappable-inference-formats-spimzcepg","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/fast-reliable-a2ui-with-swappable-inference-formats-spimzcepg"},"datePublished":"2026-10-27T15:19:10.175Z","dateModified":"2026-10-27T15:29:31.884Z","description":"Google's A2UI protocol adds swappable inference formats to speed up generative UI generation. 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