fix(mcp): resolve React duplicate module error with dedupe config

Fixes a React runtime error where `useRef` was null due to multiple React instances being bundled.

## Changes Made

- **Vite configuration**: Added `resolve.dedupe` for `react` and `react-dom` in `examples/mcp/vite.config.ts` to ensure only one instance of React is used during bundling
- **React version constraints**: Changed from exact versions (`19.2.3`) to flexible ranges (`^19.0.0`) in `examples/mcp/package.json` to improve compatibility
- **Build entry point**: Added new `build-app-html-entry.ts` file and updated `tsup.config.ts` to include it as a build target
- **Package exports**: Added `./build-app-html` export path in `packages/mcp/package.json`
- **Minor fixes**: Updated Next.js type reference path in stripe-app example

The root cause was React being duplicated in the bundle, causing hooks like `useRef` to fail when components tried to access React's internal state from the wrong instance. The `dedupe` configuration ensures Vite resolves all React imports to the same module instance.

Fixes #190

AGENTS.md

@@ -98,7 +98,7 @@ When asked to prepare a release (e.g. "prepare v0.12.0"):
    - An API reference page at `apps/web/app/(main)/docs/api/<name>/page.mdx`
    - An entry in `apps/web/lib/page-titles.ts` and `apps/web/lib/docs-navigation.ts`
    - An entry in the docs-chat system prompt (`apps/web/app/api/docs-chat/route.ts`)
-   - A skill at `skills/json-render-<name>/SKILL.md`
+   - A skill at `skills/<name>/SKILL.md`
    - A `packages/<name>/README.md`
 6. **Run `pnpm type-check`** after all changes to verify nothing is broken
 

apps/web/app/(main)/docs/skills/page.mdx

@@ -0,0 +1,117 @@
+import { pageMetadata } from "@/lib/page-metadata"
+
+export const metadata = pageMetadata("docs/skills")
+
+# Skills
+
+json-render ships with skills that teach AI coding agents how to use each package. Install a skill and your agent in Cursor, Claude Code, or Codex can generate json-render UIs without manual guidance.
+
+## Available Skills
+
+- **core** — Core schemas, catalogs, and AI prompt generation.
+- **react** — React renderer that turns JSON specs into React component trees.
+- **react-pdf** — PDF renderer using `@react-pdf/renderer`.
+- **react-email** — Email renderer that produces HTML or plain-text emails.
+- **react-native** — React Native renderer for native mobile UIs.
+- **shadcn** — Pre-built shadcn/ui components (Radix UI + Tailwind).
+- **image** — Image renderer that turns JSON specs into SVG and PNG via Satori.
+- **remotion** — Remotion renderer for video generation from JSON timeline specs.
+- **vue** — Vue 3 renderer for Vue component trees.
+- **svelte** — Svelte 5 renderer for Svelte component trees.
+- **codegen** — Code generation utilities for building custom exporters.
+- **mcp** — MCP Apps integration for Claude, ChatGPT, Cursor, and VS Code.
+- **redux** — Redux adapter for json-render's `StateStore` interface.
+- **zustand** — Zustand adapter for json-render's `StateStore` interface.
+- **jotai** — Jotai adapter for json-render's `StateStore` interface.
+- **xstate** — XState Store adapter for json-render's `StateStore` interface.
+
+## Installation
+
+```bash
+npx skills add vercel-labs/json-render --skill core
+npx skills add vercel-labs/json-render --skill react
+npx skills add vercel-labs/json-render --skill react-pdf
+npx skills add vercel-labs/json-render --skill react-email
+npx skills add vercel-labs/json-render --skill react-native
+npx skills add vercel-labs/json-render --skill shadcn
+npx skills add vercel-labs/json-render --skill image
+npx skills add vercel-labs/json-render --skill remotion
+npx skills add vercel-labs/json-render --skill vue
+npx skills add vercel-labs/json-render --skill svelte
+npx skills add vercel-labs/json-render --skill codegen
+npx skills add vercel-labs/json-render --skill mcp
+npx skills add vercel-labs/json-render --skill redux
+npx skills add vercel-labs/json-render --skill zustand
+npx skills add vercel-labs/json-render --skill jotai
+npx skills add vercel-labs/json-render --skill xstate
+```
+
+After installing, your AI agent will automatically activate the right skill when it encounters a matching request.
+
+## core
+
+The foundational skill. Teaches agents how to define catalogs, create schemas, build specs, and generate AI prompts. This is the starting point for any json-render project and covers `defineCatalog`, `defineSchema`, `specSchema`, `toPrompt`, and the full spec format.
+
+## react
+
+Teaches agents how to render JSON specs as React component trees using `JsonRender`, `JsonRenderClient`, and `useJsonRender`. Covers custom component registries, client-side interactivity, state management, and streaming integration.
+
+## react-pdf
+
+Teaches agents how to generate PDFs from JSON specs using `@react-pdf/renderer`. Covers the PDF-specific component registry, page layout, and styling.
+
+## react-email
+
+Teaches agents how to render JSON specs as HTML or plain-text emails using React Email components. Covers the email-specific registry and rendering pipeline.
+
+## react-native
+
+Teaches agents how to render JSON specs as native mobile UIs with React Native. Covers the native component registry and platform-specific considerations.
+
+## shadcn
+
+Teaches agents how to use the pre-built shadcn/ui component registry with json-render. Includes Radix UI primitives, Tailwind styling, and the full set of available shadcn components.
+
+## image
+
+Teaches agents how to turn JSON specs into SVG and PNG images using Satori. Covers the image-specific registry, dimensions, fonts, and rendering options.
+
+## remotion
+
+Teaches agents how to generate videos from JSON timeline specs using Remotion. Covers compositions, sequences, timeline structure, and video rendering.
+
+## vue
+
+Teaches agents how to render JSON specs as Vue 3 component trees. Covers the Vue renderer API, custom component registries, and reactivity integration.
+
+## svelte
+
+Teaches agents how to render JSON specs as Svelte 5 component trees. Covers the Svelte renderer API and component registration.
+
+## codegen
+
+Teaches agents how to use code generation utilities to export UI specs as framework-specific source code. Covers the codegen pipeline and custom exporter creation.
+
+## mcp
+
+Teaches agents how to build MCP Apps that serve json-render UIs inside AI tools like Claude, ChatGPT, Cursor, and VS Code. Covers MCP server setup, tool definitions, and UI streaming.
+
+## redux
+
+Teaches agents how to connect a Redux store to json-render's `StateStore` interface for state-driven UIs.
+
+## zustand
+
+Teaches agents how to connect a Zustand store to json-render's `StateStore` interface for lightweight state management.
+
+## jotai
+
+Teaches agents how to connect Jotai atoms to json-render's `StateStore` interface for atomic state management.
+
+## xstate
+
+Teaches agents how to connect an XState Store to json-render's `StateStore` interface for state-machine-driven UIs.
+
+## Source
+
+All skill files are in the [`skills/`](https://github.com/vercel-labs/json-render/tree/main/skills) directory of the repository.

apps/web/app/api/docs-chat/route.ts

@@ -17,6 +17,7 @@ const SYSTEM_PROMPT = `You are a helpful documentation assistant for json-render
 GitHub repository: https://github.com/vercel-labs/json-render
 Documentation: https://json-render.dev/docs
 npm packages: @json-render/core, @json-render/react, @json-render/vue, @json-render/svelte, @json-render/shadcn, @json-render/react-native, @json-render/react-email, @json-render/react-pdf, @json-render/image, @json-render/remotion, @json-render/codegen, @json-render/mcp, @json-render/redux, @json-render/zustand, @json-render/jotai, @json-render/xstate
+Skills: json-render ships AI agent skills that teach coding agents how to use each package. Install with "npx skills add vercel-labs/json-render --skill <name>". Available skills: core, react, react-pdf, react-email, react-native, shadcn, image, remotion, vue, svelte, codegen, mcp, redux, zustand, jotai, xstate. See /docs/skills for details.
 
 You have access to the full json-render documentation via the bash and readFile tools. The docs are available as markdown files in the /workspace/docs/ directory.
 

apps/web/lib/docs-navigation.ts

@@ -16,6 +16,7 @@ export const docsNavigation: NavSection[] = [
       { title: "Introduction", href: "/docs" },
       { title: "Installation", href: "/docs/installation" },
       { title: "Quick Start", href: "/docs/quick-start" },
+      { title: "Skills", href: "/docs/skills" },
       { title: "Migration Guide", href: "/docs/migration" },
       { title: "Changelog", href: "/docs/changelog" },
     ],

apps/web/lib/page-titles.ts

@@ -37,6 +37,7 @@ export const PAGE_TITLES: Record<string, string> = {
   "docs/ag-ui": "AG-UI Integration",
   "docs/migration": "Migration Guide",
   "docs/changelog": "Changelog",
+  "docs/skills": "Skills",
 
   // API references
   "docs/api/core": "@json-render/core API",

examples/mcp/package.json

@@ -16,8 +16,8 @@
     "@json-render/shadcn": "workspace:*",
     "@modelcontextprotocol/ext-apps": "^1.2.0",
     "@modelcontextprotocol/sdk": "^1.27.1",
-    "react": "19.2.3",
-    "react-dom": "19.2.3",
+    "react": "^19.0.0",
+    "react-dom": "^19.0.0",
     "zod": "^4.3.6"
   },
   "devDependencies": {

examples/mcp/vite.config.ts

@@ -5,6 +5,9 @@ import tailwindcss from "@tailwindcss/vite";
 
 export default defineConfig({
   plugins: [react(), tailwindcss(), viteSingleFile()],
+  resolve: {
+    dedupe: ["react", "react-dom"],
+  },
   build: {
     outDir: "dist",
     emptyOutDir: false,

examples/stripe-app/api/next-env.d.ts

@@ -1,6 +1,6 @@
 /// <reference types="next" />
 /// <reference types="next/image-types/global" />
-import "./.next/dev/types/routes.d.ts";
+import "./.next/types/routes.d.ts";
 
 // NOTE: This file should not be edited
 // see https://nextjs.org/docs/app/api-reference/config/typescript for more information.

packages/mcp/package.json

@@ -42,6 +42,11 @@
       "types": "./dist/app.d.ts",
       "import": "./dist/app.mjs",
       "require": "./dist/app.js"
+    },
+    "./build-app-html": {
+      "types": "./dist/build-app-html-entry.d.ts",
+      "import": "./dist/build-app-html-entry.mjs",
+      "require": "./dist/build-app-html-entry.js"
     }
   },
   "files": [

packages/mcp/src/build-app-html-entry.ts

@@ -0,0 +1,11 @@
+/**
+ * Server-side utility for building self-contained MCP App HTML.
+ *
+ * This entry point does NOT depend on React and is safe to import
+ * in Node.js / server environments.
+ *
+ * @packageDocumentation
+ */
+
+export { buildAppHtml } from "./build-app-html.js";
+export type { BuildAppHtmlOptions } from "./build-app-html.js";

packages/mcp/tsup.config.ts

@@ -1,7 +1,7 @@
 import { defineConfig } from "tsup";
 
 export default defineConfig({
-  entry: ["src/index.ts", "src/app.ts"],
+  entry: ["src/index.ts", "src/app.ts", "src/build-app-html-entry.ts"],
   format: ["cjs", "esm"],
   dts: true,
   sourcemap: true,

pnpm-lock.yaml

@@ -536,16 +536,16 @@ importers:
         version: link:../../packages/shadcn
       '@modelcontextprotocol/ext-apps':
         specifier: ^1.2.0
-        version: 1.2.0(@modelcontextprotocol/sdk@1.27.1(zod@4.3.6))(react-dom@19.2.3(react@19.2.3))(react@19.2.3)(zod@4.3.6)
+        version: 1.2.0(@modelcontextprotocol/sdk@1.27.1(zod@4.3.6))(react-dom@19.2.4(react@19.2.4))(react@19.2.4)(zod@4.3.6)
       '@modelcontextprotocol/sdk':
         specifier: ^1.27.1
         version: 1.27.1(zod@4.3.6)
       react:
-        specifier: 19.2.3
-        version: 19.2.3
+        specifier: ^19.0.0
+        version: 19.2.4
       react-dom:
-        specifier: 19.2.3
-        version: 19.2.3(react@19.2.3)
+        specifier: ^19.0.0
+        version: 19.2.4(react@19.2.4)
       zod:
         specifier: ^4.3.6
         version: 4.3.6
@@ -600,7 +600,7 @@ importers:
         version: 0.563.0(react@19.2.4)
       next:
         specifier: 16.1.6
-        version: 16.1.6(@opentelemetry/api@1.9.0)(babel-plugin-react-compiler@1.0.0)(react-dom@19.2.4(react@19.2.4))(react@19.2.4)
+        version: 16.1.6(@babel/core@7.29.0)(@opentelemetry/api@1.9.0)(babel-plugin-react-compiler@1.0.0)(react-dom@19.2.4(react@19.2.4))(react@19.2.4)
       radix-ui:
         specifier: ^1.4.3
         version: 1.4.3(@types/react-dom@19.2.3(@types/react@19.2.3))(@types/react@19.2.3)(react-dom@19.2.4(react@19.2.4))(react@19.2.4)
@@ -947,7 +947,7 @@ importers:
         version: 6.0.103(zod@4.3.6)
       next:
         specifier: ^16.1.6
-        version: 16.1.6(@opentelemetry/api@1.9.0)(babel-plugin-react-compiler@1.0.0)(react-dom@19.2.4(react@19.2.4))(react@19.2.4)
+        version: 16.1.6(@babel/core@7.29.0)(@opentelemetry/api@1.9.0)(babel-plugin-react-compiler@1.0.0)(react-dom@19.2.4(react@19.2.4))(react@19.2.4)
       react:
         specifier: ^19.1.0
         version: 19.2.4
@@ -15019,14 +15019,6 @@ snapshots:
 
   '@mixmark-io/domino@2.2.0': {}
 
-  '@modelcontextprotocol/ext-apps@1.2.0(@modelcontextprotocol/sdk@1.27.1(zod@4.3.6))(react-dom@19.2.3(react@19.2.3))(react@19.2.3)(zod@4.3.6)':
-    dependencies:
-      '@modelcontextprotocol/sdk': 1.27.1(zod@4.3.6)
-      zod: 4.3.6
-    optionalDependencies:
-      react: 19.2.3
-      react-dom: 19.2.3(react@19.2.3)
-
   '@modelcontextprotocol/ext-apps@1.2.0(@modelcontextprotocol/sdk@1.27.1(zod@4.3.6))(react-dom@19.2.4(react@19.2.4))(react@19.2.4)(zod@4.3.6)':
     dependencies:
       '@modelcontextprotocol/sdk': 1.27.1(zod@4.3.6)
@@ -17941,7 +17933,7 @@ snapshots:
   '@stripe/ui-extension-tools@0.0.1(@babel/core@7.29.0)(babel-jest@27.5.1(@babel/core@7.29.0))':
     dependencies:
       '@types/jest': 28.1.8
-      '@typescript-eslint/eslint-plugin': 5.62.0(@typescript-eslint/parser@5.62.0(eslint@9.39.2(jiti@2.6.1))(typescript@4.9.5))(eslint@8.57.1)(typescript@4.9.5)
+      '@typescript-eslint/eslint-plugin': 5.62.0(@typescript-eslint/parser@5.62.0(eslint@8.57.1)(typescript@4.9.5))(eslint@8.57.1)(typescript@4.9.5)
       '@typescript-eslint/parser': 5.62.0(eslint@8.57.1)(typescript@4.9.5)
       eslint: 8.57.1
       eslint-plugin-react: 7.37.5(eslint@8.57.1)
@@ -18467,7 +18459,7 @@ snapshots:
       '@types/node': 22.19.6
     optional: true
 
-  '@typescript-eslint/eslint-plugin@5.62.0(@typescript-eslint/parser@5.62.0(eslint@9.39.2(jiti@2.6.1))(typescript@4.9.5))(eslint@8.57.1)(typescript@4.9.5)':
+  '@typescript-eslint/eslint-plugin@5.62.0(@typescript-eslint/parser@5.62.0(eslint@8.57.1)(typescript@4.9.5))(eslint@8.57.1)(typescript@4.9.5)':
     dependencies:
       '@eslint-community/regexpp': 4.12.2
       '@typescript-eslint/parser': 5.62.0(eslint@8.57.1)(typescript@4.9.5)
@@ -23804,32 +23796,6 @@ snapshots:
       - '@babel/core'
       - babel-plugin-macros
 
-  next@16.1.6(@opentelemetry/api@1.9.0)(babel-plugin-react-compiler@1.0.0)(react-dom@19.2.4(react@19.2.4))(react@19.2.4):
-    dependencies:
-      '@next/env': 16.1.6
-      '@swc/helpers': 0.5.15
-      baseline-browser-mapping: 2.9.14
-      caniuse-lite: 1.0.30001764
-      postcss: 8.4.31
-      react: 19.2.4
-      react-dom: 19.2.4(react@19.2.4)
-      styled-jsx: 5.1.6(react@19.2.4)
-    optionalDependencies:
-      '@next/swc-darwin-arm64': 16.1.6
-      '@next/swc-darwin-x64': 16.1.6
-      '@next/swc-linux-arm64-gnu': 16.1.6
-      '@next/swc-linux-arm64-musl': 16.1.6
-      '@next/swc-linux-x64-gnu': 16.1.6
-      '@next/swc-linux-x64-musl': 16.1.6
-      '@next/swc-win32-arm64-msvc': 16.1.6
-      '@next/swc-win32-x64-msvc': 16.1.6
-      '@opentelemetry/api': 1.9.0
-      babel-plugin-react-compiler: 1.0.0
-      sharp: 0.34.5
-    transitivePeerDependencies:
-      - '@babel/core'
-      - babel-plugin-macros
-
   node-abi@3.87.0:
     dependencies:
       semver: 7.7.3
@@ -25904,11 +25870,6 @@ snapshots:
       client-only: 0.0.1
       react: 19.2.3
 
-  styled-jsx@5.1.6(react@19.2.4):
-    dependencies:
-      client-only: 0.0.1
-      react: 19.2.4
-
   sucrase@3.35.1:
     dependencies:
       '@jridgewell/gen-mapping': 0.3.13

skills/codegen/SKILL.md

@@ -1,5 +1,5 @@
 ---
-name: json-render-codegen
+name: codegen
 description: Code generation utilities for json-render. Use when generating code from UI specs, building custom code exporters, traversing specs, or serializing props for @json-render/codegen.
 ---
 

skills/core/SKILL.md

@@ -1,5 +1,5 @@
 ---
-name: json-render-core
+name: core
 description: Core package for defining schemas, catalogs, and AI prompt generation for json-render. Use when working with @json-render/core, defining schemas, creating catalogs, or building JSON specs for UI/video generation.
 ---
 

skills/image/SKILL.md

@@ -1,5 +1,5 @@
 ---
-name: json-render-image
+name: image
 description: Image renderer for json-render that turns JSON specs into SVG and PNG images via Satori. Use when working with @json-render/image, generating OG images from JSON, creating social cards, or rendering AI-generated image specs.
 ---
 

skills/jotai/SKILL.md

@@ -1,5 +1,5 @@
 ---
-name: json-render-jotai
+name: jotai
 description: Jotai adapter for json-render's StateStore interface. Use when integrating json-render with Jotai for state management via @json-render/jotai.
 ---
 

skills/mcp/SKILL.md

@@ -1,5 +1,5 @@
 ---
-name: json-render-mcp
+name: mcp
 description: MCP Apps integration for json-render. Use when building MCP servers that render interactive UIs in Claude, ChatGPT, Cursor, or VS Code, or when integrating json-render with the Model Context Protocol.
 ---
 

skills/react-email/SKILL.md

@@ -1,5 +1,5 @@
 ---
-name: json-render-react-email
+name: react-email
 description: React Email renderer for json-render that turns JSON specs into HTML or plain-text emails using @react-email/components and @react-email/render. Use when working with @json-render/react-email, building transactional or marketing emails from JSON, creating email catalogs, rendering AI-generated email specs, or when the user mentions react-email, HTML email, or transactional email.
 metadata:
   tags: react-email, email, json-render, html email, transactional email

skills/react-native/SKILL.md

@@ -1,5 +1,5 @@
 ---
-name: json-render-react-native
+name: react-native
 description: React Native renderer for json-render that turns JSON specs into native mobile UIs. Use when working with @json-render/react-native, building React Native UIs from JSON, creating mobile component catalogs, or rendering AI-generated specs on mobile.
 ---
 

skills/react-pdf/SKILL.md

@@ -1,5 +1,5 @@
 ---
-name: json-render-react-pdf
+name: react-pdf
 description: React PDF renderer for json-render. Use when generating PDF documents from JSON specs, working with @json-render/react-pdf, or rendering specs to PDF buffers/streams/files.
 ---
 

skills/react/SKILL.md

@@ -1,5 +1,5 @@
 ---
-name: json-render-react
+name: react
 description: React renderer for json-render that turns JSON specs into React components. Use when working with @json-render/react, building React UIs from JSON, creating component catalogs, or rendering AI-generated specs.
 ---
 

skills/redux/SKILL.md

@@ -1,5 +1,5 @@
 ---
-name: json-render-redux
+name: redux
 description: Redux adapter for json-render's StateStore interface. Use when integrating json-render with Redux or Redux Toolkit for state management via @json-render/redux.
 ---
 

skills/remotion/SKILL.md

@@ -1,5 +1,5 @@
 ---
-name: json-render-remotion
+name: remotion
 description: Remotion renderer for json-render that turns JSON timeline specs into videos. Use when working with @json-render/remotion, building video compositions from JSON, creating video catalogs, or rendering AI-generated video timelines.
 ---
 

skills/shadcn/SKILL.md

@@ -1,5 +1,5 @@
 ---
-name: json-render-shadcn
+name: shadcn
 description: Pre-built shadcn/ui components for json-render. Use when working with @json-render/shadcn, adding standard UI components to a catalog, or building web UIs with Radix UI + Tailwind CSS components.
 ---
 

skills/svelte/SKILL.md

@@ -1,5 +1,5 @@
 ---
-name: json-render-svelte
+name: svelte
 description: Svelte 5 renderer for json-render that turns JSON specs into Svelte component trees. Use when working with @json-render/svelte, building Svelte UIs from JSON, creating component catalogs, or rendering AI-generated specs.
 ---
 

skills/vue/SKILL.md

@@ -1,5 +1,5 @@
 ---
-name: json-render-vue
+name: vue
 description: Vue 3 renderer for json-render. Use when building Vue UIs from JSON specs, working with @json-render/vue, defining Vue component registries, or rendering AI-generated specs in Vue.
 ---
 

skills/xstate/SKILL.md

@@ -1,5 +1,5 @@
 ---
-name: json-render-xstate
+name: xstate
 description: XState Store adapter for json-render's StateStore interface. Use when integrating json-render with @xstate/store for state management via @json-render/xstate.
 ---
 

skills/zustand/SKILL.md

@@ -1,5 +1,5 @@
 ---
-name: json-render-zustand
+name: zustand
 description: Zustand adapter for json-render's StateStore interface. Use when integrating json-render with Zustand for state management via @json-render/zustand.
 ---