Chatgpt App Builder

What it does

When your agent uses it

• Creating ChatGPT apps
• Building MCP servers with widgets
• Defining React widgets
• Working with Apps SDK

Example prompts

• “/chatgpt-app-builder”

Requirements

• Node.js

What it can do on your machine

Read from SKILL.md and the folder at commit 44923f3. It shows what the files ask for, not the result of running them.

• Tool permissions

  Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

  From allowed-tools in the SKILL.md frontmatter.

• Runs code

  No scripts in the folder and no shell commands in SKILL.md (its code samples are typescript).

  From the folder's file list and the shell code blocks in SKILL.md.

• Network

  No URLs in SKILL.md.

  From URLs in SKILL.md, links to its own repository left out.

• Credentials

  Names no API keys, tokens, secrets or passwords.

  From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Chatgpt App Builder loads about 787 tokens when it runs, and up to ~13k if it reads all its reference files. Until then it costs about 136 tokens; SKILL.md has 187 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it

~136

When it runs · the whole SKILL.md, loaded when a task matches

~787

With references · SKILL.md plus every file in references/, read only if the agent opens them

~13k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from aiskillstore/marketplace at commit 44923f3, republished under its Apache-2.0 licence (© aiskillstore). 187 words, ~787 tokens.

name

chatgpt-app-builder

description

DEPRECATED: This skill has been replaced by `mcp-app-builder`. Check if `mcp-app-builder` is available in the skills folder. If not, install it: `npx skills install mcp-use/mcp-use --skill mcp-app-builder` Use `mcp-app-builder` instead of this skill. Build ChatGPT apps with interactive widgets using mcp-use and OpenAI Apps SDK. Use when creating ChatGPT apps, building MCP servers with widgets, defining React widgets, working with Apps SDK, or when user mentions ChatGPT widgets, mcp-use widgets, or Apps SDK development.

// Server
import { MCPServer, widget, text, object } from "mcp-use/server";
server.tool({ name: "...", schema: z.object({...}), widget: { name: "widget-name" } },
  async (input) => widget({ props: {...}, output: text("...") })
);

// Widget (resources/widget-name.tsx)
import { McpUseProvider, useWidget, type WidgetMetadata } from "mcp-use/react";
export const widgetMetadata: WidgetMetadata = { description: "...", props: z.object({...}) };
export default function MyWidget() {
  const { props, isPending, callTool, sendFollowUpMessage, state, setState, theme } = useWidget();
  if (isPending) return <McpUseProvider autoSize><div>Loading...</div></McpUseProvider>;
  return <McpUseProvider autoSize><div>{/* UI */}</div></McpUseProvider>;
}

© aiskillstore, Apache-2.0. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 18 other files (references) in skills/mcp-use/chatgpt-app-builder of aiskillstore/marketplace.

• SKILL.md
• LICENSE.txt
• evals/README.md
• evals/architecture.json
• evals/discover.json
• evals/skill.json
• evals/state-and-context.json
• evals/ui-guidelines.json
• evals/widgets.json
• references/architecture.md
• references/components-api.md
• references/csp-and-metadata.md
• references/discover.md
• references/server-and-widgets.md
• references/setup.md
• references/state-and-context.md
• references/ui-guidelines.md
• references/widget-patterns.md
• skill-report.json

Open the folder on GitHubat commit 44923f3