Json-Render

Json-Render is a developer tool that generates constrained, component-based UIs from prompts. An open source framework that turns prompts into React interfaces by forcing the model to emit JSON constrained to a developer-defined component catalog, with streaming rendering, state binding and export to standalone code.

Json-Render is a generative UI framework from vercel-labs that turns natural language prompts into working interfaces. Instead of letting a model emit arbitrary markup, it asks the model to produce a JSON document that describes a layout: which components appear, which props they carry, and how they nest. Those components come from a catalog the developer writes, so the model can only assemble interfaces from pre-approved building blocks. The output is predictable enough to render natively in React instead of being sanitized HTML. The workflow has three stages. First, define your catalog with defineSchema and defineCatalog from @json-render/core, describing each component's props with Zod and registering the actions a model may call. Second, send a prompt and receive JSON constrained to that catalog. Third, stream the response so the interface fills in progressively as elements arrive. Data binding works through $state, $item and $index references, and form controls support two-way binding through $bindState. The shipped catalog covers 41 components (Metric, LineGraph, Table, Carousel, Dialog and more) plus 6 actions. This is aimed at product engineers building AI features inside an app: dashboards, widgets, receipts, recipe cards, personalized onboarding screens. React and React Native share one catalog and spec format, and generated trees can be exported as a standalone Next.js project with package.json, component files and styles, with no runtime dependency on the framework. Compared with generic prompt-to-HTML approaches, the tradeoff is control over variety. Json-Render will not invent a layout your catalog cannot express, which is what makes it safe for production surfaces but limits it as a freeform design tool. It is a library rather than a hosted product, so expect to install packages and write schema code.