openai-apps-mcplisted
Install: claude install-skill rkz91/coco
# Building OpenAI Apps with Stateless MCP Servers
**Status**: Production Ready
**Last Updated**: 2026-01-21
**Dependencies**: `cloudflare-worker-base`, `hono-routing` (optional)
**Latest Versions**: @modelcontextprotocol/sdk@1.25.3, hono@4.11.3, zod@4.3.5, wrangler@4.58.0
---
## Overview
Build **ChatGPT Apps** using **MCP (Model Context Protocol)** servers on Cloudflare Workers. Extends ChatGPT with custom tools and interactive widgets (HTML/JS UI rendered in iframe).
**Architecture**: ChatGPT → MCP endpoint (JSON-RPC 2.0) → Tool handlers → Widget resources (HTML)
**Status**: Apps available to Business/Enterprise/Edu (GA Nov 13, 2025). MCP Apps Extension (SEP-1865) formalized Nov 21, 2025.
---
## Quick Start
### 1. Scaffold & Install
```bash
npm create cloudflare@latest my-openai-app -- --type hello-world --ts --git --deploy false
cd my-openai-app
npm install @modelcontextprotocol/sdk@1.25.3 hono@4.11.3 zod@4.3.5
npm install -D @cloudflare/vite-plugin@1.17.1 vite@7.2.4
```
### 2. Configure wrangler.jsonc
```jsonc
{
"name": "my-openai-app",
"main": "dist/index.js",
"compatibility_flags": ["nodejs_compat"], // Required for MCP SDK
"assets": {
"directory": "dist/client",
"binding": "ASSETS" // Must match TypeScript
}
}
```
### 3. Create MCP Server (`src/index.ts`)
```typescript
import { Hono } from 'hono';
import { cors } from 'hono/cors';
import { Server } from '@modelcontextprotocol/sdk/server/index.js';
import { ListToolsRequestSchema, CallTo