# ChatGPT App Builder

Builds, debugs and reviews TypeScript MCP servers and MCP Apps with mcp-use.

- Repository: https://github.com/mcp-use/mcp-use (10837 stars)
- Category: Engineering
- License: MIT
- Last updated: 2026-10-30
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add mcp-use/mcp-use --skill chatgpt-app-builder -g -a claude-code -y`
Codex: `npx skills add mcp-use/mcp-use --skill chatgpt-app-builder -g -a codex -y`
Cursor: `npx skills add mcp-use/mcp-use --skill chatgpt-app-builder -g -a cursor -y`
Gemini CLI: `npx skills add mcp-use/mcp-use --skill chatgpt-app-builder -g -a gemini-cli -y`
Claude Code plugin marketplace: `/plugin marketplace add mcp-use/mcp-use`

## Description

Build, modify, debug, migrate, review, or verify TypeScript MCP servers and MCP Apps with mcp-use. Use for tools, resources, prompts, middleware, Views, authentication, Skills over MCP, scaffolding, and advanced features.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# Build with mcp-use

Treat the installed `mcp-use` package, its exported types, generated declarations, and the project's existing code as the source of truth. Inspect the installed version before choosing APIs or changing code.

## Workflow

1. Inspect `package.json`, the server entry, exported tool refs, `mcp-env.d.ts`, `views/`, `skills/`, and the installed `mcp-use` version.
2. Scaffold a new stable project with `create-mcp-use-app@latest` and the appropriate template. Match the package version or dist-tag when working on beta, canary, or an existing versioned project.
3. Read only the references needed for the task:
   - [Server](references/server.md) for tools, resources, prompts, MCP middleware, request context, and result envelopes.
   - [Views](references/views.md) for interactive MCP Apps, React hooks, model context, host capabilities, assets, CSP, and endpoint/UI domain handling.
   - [Authentication](references/auth.md) for OAuth providers, verified identity, scopes, permissions, and authorization.
   - [Skills over MCP](references/skills-over-mcp.md) when a server should ship reusable workflows alongside its tools.
   - [Advanced features](references/advanced-features.md) for OpenAPI, proxying, notifications, subscriptions, and elicitation.
   - [Migration](references/migration.md) only when retired or compatibility-only imports, helpers, registration shapes, UI patterns, or session assumptions are present.
   - [Verification](references/verification.md) before reporting implementation work complete.
4. Implement against installed types. Prefer the framework's current conventions over copied examples or historical changelogs.
5. Validate the smallest real lifecycle that proves the changed behavior, then expand checks in proportion to risk.

## Core invariants

The rest: https://github.com/mcp-use/mcp-use/blob/HEAD/skills/chatgpt-app-builder/SKILL.md