ChatGPT Apps SDK Next.js Starter

A minimal Next.js application demonstrating how to build an OpenAI Apps SDK compatible MCP server with widget rendering in ChatGPT.

Overview

This project shows how to integrate a Next.js application with the ChatGPT Apps SDK using the Model Context Protocol (MCP). It includes a working MCP server that exposes tools and resources that can be called from ChatGPT, with responses rendered natively in ChatGPT.

Key Components

1. MCP Server Route (app/mcp/route.ts)

The core MCP server implementation that exposes tools and resources to ChatGPT.

Key features:

• Tool registration with OpenAI-specific metadata
• Resource registration that serves HTML content for iframe rendering
• Cross-linking between tools and resources via templateUri

OpenAI-specific metadata:

{
  "openai/outputTemplate": widget.templateUri,      // Links to resource
  "openai/toolInvocation/invoking": "Loading...\