OpenUI
Open Standard for Generative UI
Loved by 50,000+ developers from
OpenUI Open Source
Make your AI apps and agentsrespond with Interactive UI, Charts, Tables, Forms, Dashboards
Works with the tools you already use.
Works with any model, any frontend framework, and any design system or component library you already use.
Your model
Closed or open, hosted or running on your own machine.
OpenAI, Anthropic, Gemini, DeepSeek, xAI, Mistral, Qwen, Ollama
Your agents
Add it to your existing agent code. No rewrite needed.
Vercel AI SDK, LangChain, LangGraph, Convex, Cloudflare, CrewAI, n8n, Haystack
Your components
Bring your own design system and component library.
OpenUI Design system, shadcn/ui, Material UI, Ant Design, Radix UI, Chakra UI, Mantine, daisyUI
Your framework
Works in the web framework you build with today.
React, Next.js, Vue, Svelte, Angular, Nuxt, Remix, Astro
Faster answers,
fewer tokens.
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.
Keep your existing SDK
Chat Completions and Responses endpoints work with existing SDKs.
Repair before users see it
Fix invalid output as it streams, before it reaches users.
Stay online through outages
Gateway switches providers if one fails, keeping the same model.
Use existing LLM spend
Use your existing model provider credentials and commitments.
Keep your existing SDK
Chat Completions and Responses endpoints work with existing SDKs.
Repair before users see it
Fix invalid output as it streams, before it reaches users.
Stay online through outages
Gateway switches providers if one fails, keeping the same model.
Use existing LLM spend
Use your existing model provider credentials and commitments.
Trusted by thousands of developers
Frequently asked questions
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What should I use to build a Generative UI app?
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.
How can I set up my coding agent to use OpenUI?
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.
What is OpenUI Lang?
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.
Is OpenUI only for chat?
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.
Is OpenUI free and open source?
Yes. OpenUI is fully open source and works with your own components and design system.
Do I need both Gateway and Observability?
No. They work independently.
We recommend using both. Gateway makes generated UI more reliable. Observability shows what users experienced and whether it worked.
How is Thesys related to OpenUI?
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.