chatgpt-app-builder
A ChatGPT reply that comes back as a live panel rather than plain text — a weather card, a filterable product grid — built as one React file that the server picks up and wires into the chat on its own.
LABSCO SUMMARY
Summary
mcp-use/skills packages two skills, one that scaffolds an MCP server and one that adds an OpenAI Apps SDK widget to it, and both assume the mcp-use npm framework rather than MCP development in general.
mcp-builder walks through npx create-mcp-use-app, defining tools, resources, and prompts in that scaffold, testing locally with an Inspector UI, opening a tunnel so ChatGPT can reach a server still running on your machine, and deploying to "mcp-use Cloud" or elsewhere once it works. chatgpt-app-builder sits on top of that: it teaches an agent to define a React widget's props with a Zod schema, set metadata like connectDomains and resourceDomains for the widget's content-security policy, and wire it so the same tool call works for both ChatGPT Apps and the Apps SDK's own widget rendering.
This is narrow by design: both skills assume you've already chosen the mcp-use npm framework and its CLI, end to end. Someone building an MCP server with the plain Anthropic or FastMCP SDKs, or a ChatGPT plugin without mcp-use in the stack, will find little here that transfers directly — the value is entirely in knowing this one framework's own commands and conventions.
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Both skills' example content trips our install checker, for a mundane reason rather than a broken dependency.
mcp-builder cites https://happy-cat.local.mcp-use.run/mcp as the shape of the URL a --tunnel run prints out, not a real endpoint, so a link check correctly finds nothing there. chatgpt-app-builder's cdn.weather.com and embed.weather.com are illustrative domains inside a sample weather widget's CSP config, the same category of placeholder. We're recording both here because our own checks flagged them, not because either skill is actually broken.
This is a young, single-vendor collection.
The repository has 1 star, and its own "Upcoming Skills" section still just reads "More skills coming soon!" — worth knowing before treating this as a mature or widely-used package.
WHAT'S INSIDE
Skills
mcp-builder
Builds the connector that lets an AI chat assistant reach your own data and run your own code, and takes it from an empty folder to a live web address you paste into the assistant.
PLUGINS3 items
PLUGIN
all-skills
Complete collection of mcp-use skills including MCP server building and ChatGPT app development
PLUGIN
mcp-builder
Build Model Context Protocol (MCP) servers with mcp-use framework. Includes quick start, tools, resources, prompts, testing, and deployment guidance.
PLUGIN
chatgpt-app-builder
Build custom ChatGPT apps and GPTs with actions, function calling, and best practices. Includes GPT configuration, OpenAPI schemas, authentication, and deployment guidance.
INSTALL
Install
CHOOSE SKILLS
Install skills from this package (2 skills)
Run this outside your AI tool, using Node.js 22.20.0 or newer. Skills CLI 1.7.2 starts with no skills selected; prompts cancel installation without an interactive terminal. For project installation, open your project's folder first.
Install checklist
- Use ↑/↓ to move and Space to select skills or
Select All, then Enter. Enter alone cannot continue with nothing selected. - Check selected tools if a picker appears; Claude Code may be unchecked under
Additional agents. ↑/↓ moves, Space toggles selections, Enter confirms. - Without a tool picker, check
Installing to:for your intended tool. Stop if it names a different tool. - If asked, choose
Symlink (Recommended)for shared files orCopy to all agentsfor separate copies; review the summary before confirming installation. Install the find-skills skill?defaults toYes, adding another skill for all projects. ChooseNoif you don't want that extra installation.
npx skills add mcp-use/skillsSINGLE SKILL
Or install a single skill
Run this outside your AI tool, using Node.js 22.20.0 or newer. Skills CLI 1.7.2 skips skill selection; prompts cancel installation without an interactive terminal. If choosing Project when asked about installation scope, open your project's folder before running this.
Install checklist
- Check selected tools if a picker appears; Claude Code may be unchecked under
Additional agents. ↑/↓ moves, Space toggles selections, Enter confirms. - Without a tool picker, check
Installing to:for your intended tool. Stop if it names a different tool. - If asked, choose
Symlink (Recommended)for shared files orCopy to all agentsfor separate copies; review the summary before confirming installation. Install the find-skills skill?defaults toYes, adding another skill for all projects. ChooseNoif you don't want that extra installation.
Find the skill name in the Skills tab and put it in the command before running it. Each entry there installs independently.
npx skills add mcp-use/skills --skill <YOUR_SKILL_NAME> --full-depthPLUGIN MARKETPLACE
Add the marketplace, then install the plugins you want
/plugin marketplace add mcp-use/skills/plugin install all-skills@mcp-use/plugin install mcp-builder@mcp-use/plugin install chatgpt-app-builder@mcp-useTyped inside the agent's own prompt, not in a terminal. The marketplace is called mcp-use, which is the part after the @.