GitHub Style Markdown Preview MCP App

GitHub Flavored Markdown (GFM) preview as an MCP App.

Docs: https://modelcontextprotocol.io/docs/extensions/apps

Usage

npm run build    # Build UI and server
npm run serve    # Start server on http://localhost:3001/mcp
npm run dev      # Build & serve with watch mode

Connect to Claude

1. Start the tunnel:

   npx cloudflared tunnel --url http://localhost:3001
   

2. Copy the generated URL (e.g., https://random-name.trycloudflare.com)

3. In Claude web, go to Settings > Connectors > Add custom connector

4. Enter the URL with /mcp path:

   https://<your-url>.trycloudflare.com/mcp
   

Packages

Dependencies

Package	Description
@modelcontextprotocol/ext-apps	MCP Apps SDK (server + client)
@modelcontextprotocol/sdk	MCP SDK core
react, react-dom	React UI framework
react-markdown	Markdown renderer for React
remark-gfm	GitHub Flavored Markdown plugin
github-markdown-css	GitHub style CSS
express, cors	HTTP server
zod	Schema validation

Dev Dependencies

Package	Description
vite	Build tool
vite-plugin-singlefile	Bundle into single HTML
@vitejs/plugin-react	Vite React plugin
esbuild	Server bundler
concurrently	Run multiple commands
cross-env	Cross-platform env vars
tsx	TypeScript execution
typescript	TypeScript compiler

Files

File	Description
main.ts	Entry point (HTTP/stdio transport)
server.ts	MCP server with preview-markdown tool
mcp-app.html	UI entry point
src/mcp-app.tsx	React app using useApp hook
src/markdown.tsx	Markdown component with GFM support
src/global.css	GitHub markdown styling
vite.config.ts	Vite bundler config
tsconfig.json	TypeScript config
tsconfig.server.json	Server build config