Open Standard for Generative UI
OpenUI
Open Standard for Generative UI
OpenUI Open Source
Works with any model, any frontend framework, and any design system or component library you already use.
Closed or open, hosted or running on your own machine.
OpenAI, Anthropic, Gemini, DeepSeek, xAI, Mistral, Qwen, Ollama
Add it to your existing agent code. No rewrite needed.
Vercel AI SDK, LangChain, LangGraph, Convex, Cloudflare, CrewAI, n8n, Haystack
Bring your own design system and component library.
OpenUI Design system, shadcn/ui, Material UI, Ant Design, Radix UI, Chakra UI, Mantine, daisyUI
Works in the web framework you build with today.
React, Next.js, Vue, Svelte, Angular, Nuxt, Remix, Astro
OpenUI Lang generates up to 3x faster and uses 67% fewer tokens than JSON-based UI formats. Fewer tokens means every generation finishes sooner and costs less.
Make agent responses more reliable in production. Gateway catches and repairs invalid output before users see it.

Chat Completions and Responses endpoints work with existing SDKs.
Fix invalid output as it streams, before it reaches users.
Gateway switches providers if one fails, keeping the same model.
Use your existing model provider credentials and commitments.
Chat Completions and Responses endpoints work with existing SDKs.
Fix invalid output as it streams, before it reaches users.
Gateway switches providers if one fails, keeping the same model.
Use your existing model provider credentials and commitments.
Have another question?
Join our Discord.
Start with OpenUI and OpenUI Gateway. One command scaffolds a working app: npx @openuidev/cli@latest create.
Gateway gives you free models to build with, and repairs invalid output so broken UI doesn't reach users. The same setup carries into production.
Run npx @openuidev/cli@latest setup-agent in your project. It adds OpenUI instructions to AGENTS.md, or creates the file, so Codex, Cursor, Claude Code, and other coding agents know how to build with OpenUI.
Run it again any time to refresh the instructions. Projects created with npx @openuidev/cli@latest create already include them.
OpenUI Lang is a compact, streaming-first language that LLMs write to build interfaces from your own components.
It is not JSON. Each line defines one component, such as root = Stack([header, chart]), so the interface renders while the response is still streaming.
Across the same 46 interfaces in our benchmark, OpenUI Lang averaged 1,362 output tokens per screen: 58% fewer than json-render and 52% fewer than A2UI, both JSON formats.
No. OpenUI renders whatever interface a response describes: dashboards, forms, tables, charts, and complete application screens, not only messages in a chat thread.
The same response renders through React, Vue, Svelte, React Native, email, or a plain script tag.
Yes. OpenUI is fully open source and works with your own components and design system.
No. They work independently.
We recommend using both. Gateway makes generated UI more reliable. Observability shows what users experienced and whether it worked.
Thesys is the company behind OpenUI, much like Vercel is the company behind Next.js.
Thesys maintains the open-source OpenUI framework and operates OpenUI Cloud.