building-chatgpt-apps

Build ChatGPT Apps combining FastMCP servers with embedded HTML widgets.

Updated Jan 5, 2026
One-click install
npx skills add https://github.com/hussain9491/hackathone2_phase2_Q4 --skill building-chatgpt-apps-hussain9491
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: building-chatgpt-apps
Source: https://github.com/hussain9491/hackathone2_phase2_Q4/tree/main/.claude/skills/building-chatgpt-apps
Command: npx skills add https://github.com/hussain9491/hackathone2_phase2_Q4 --skill building-chatgpt-apps-hussain9491

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes scripts (resource) and references (resource) components.

What problem does it solve?

This Skill guides developers through building interactive ChatGPT Apps by blending MCP-powered tools with embedded widgets, enabling rich UI experiences inside ChatGPT conversations and streamlining the integration workload for teams.

Core Features & Use Cases

  • Widget-backed ChatGPT Apps built with MCP servers (FastMCP) and HTML widgets.
  • Clear guidelines for widget communication via window.openai APIs (toolOutput, sendFollowUpMessage, callTool).
  • Metadata-driven widget rendering with _meta and MIME type text/html+skybridge integration.
  • Debugging templates and complete reference material to scaffold production-grade apps.

Quick Start

Start by scaffolding a FastMCP-based widget server, wiring a widget HTML resource, and returning an embedded _meta widget in the tool response.

Frequently Asked Questions about building-chatgpt-apps

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I build ChatGPT Apps with custom widgets using FastMCP?▼

You can build ChatGPT Apps with custom widgets by scaffolding a FastMCP-based widget server, wiring an HTML widget resource, and returning an embedded _meta widget in the tool response.

What MIME type is required for embedding widgets in ChatGPT conversations?▼

The required MIME type for exposing widget resources in ChatGPT Apps is text/html+skybridge, which enables rich UI experiences inside conversational responses.

How do widgets communicate with ChatGPT Apps using window.openai APIs?▼

Widgets communicate with ChatGPT Apps via window.openai APIs including toolOutput, sendFollowUpMessage, and callTool, enabling reliable user interactions and follow-up workflows.

Can I use FastMCP servers to expose tools alongside interactive HTML widgets?▼

Yes, FastMCP servers can expose MCP-backed tools alongside embedded HTML widgets, combining custom UI workflows and tool metadata within conversational app responses.

How do I debug ChatGPT widget interactions and MCP tool responses?▼

This Skill provides debugging templates and complete reference material to scaffold production-grade apps and troubleshoot widget interactions and MCP tool responses.

When do I need text/html+skybridge integration for ChatGPT Apps?▼

You need text/html+skybridge integration when teams want interactive conversational apps with custom UI, widget-based workflows, and MCP-backed tools across FastMCP servers.