OpenAI Apps MCP SKILL.md skillB
OpenAI Apps MCP from coco-research/coco is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add coco-research/coco/OpenAI Apps MCP@git:20260802.1479e32Pins git:20260802.1479e32 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- B, 16 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- coco-research/coco
- Path
skills/openai-apps-mcp/SKILL.md- Versions recorded
- 2
- Latest version
- git:20260802.1479e32, committed Aug 2, 2026
- First version recorded
- Apr 26, 2026
- Size
- 18,053 bytes
- Repository stars
- 629
- License
- Apache-2.0
Build ChatGPT apps with MCP servers on Cloudflare Workers. Extend ChatGPT with custom tools and interactive widgets (HTML/JS UI). Use when: developing ChatGPT extensions, implementing MCP servers, or troubleshooting CORS, widget 404s, MIME types, ASSETS binding errors, Next.js integration issues, or edge platform limitations.
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# Building OpenAI Apps with Stateless MCP Servers
**Status**: Production Ready
**Last Updated**: 2026-01-21
**Dependencies**: `cloudflare-worker-base`, `hono-routing` (optional)
**Latest Versions**: @modelcontextprotocol/sdk@1.25.3, hono@4.11.3, zod@4.3.5, wrangler@4.58.0
---
## Overview
Build **ChatGPT Apps** using **MCP (Model Context Protocol)** servers on Cloudflare Workers. Extends ChatGPT with custom tools and interactive widgets (HTML/JS UI rendered in iframe).
**Architecture**: ChatGPT → MCP endpoint (JSON-RPC 2.0) → Tool handlers → Widget resources (HTML)
**Status**: Apps available to Business/Enterprise/Edu (GA Nov 13, 2025). MCP Apps Extension (SEP-1865) formalized Nov 21, 2025.
---
## Quick Start
### 1. Scaffold & Install
```bash
npm create cloudflare@latest my-openai-app -- --type hello-world --ts --git --deploy false
cd my-openai-app
npm install @modelcontextprotocol/sdk@1.25.3 hono@4.11.3 zod@4.3.5
npm install -D @cloudflare/vite-plugin@1.17.1 vite@7.2.4
```
### 2. Configure wrangler.jsonc
```jsonc
{
"name": "my-openai-app",
"main": "dist/index.js",
"compatibility_flags": ["nodejs_compat"], // Required for MCP SDK
"assets": {
…Read the whole file at its exact version.
How to install
mdr add coco-research/coco/OpenAI Apps MCP@sha256:5d83efa87c6472c8The line at the top of this page pins the label git:20260802.1479e32, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_7dophjelcpwvdqie)
6 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 2 versions of this file, between Apr 26, 2026 and Aug 2, 2026, about one every 99 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20260802.1479e32 latest | 2026-08-02 | 1479e32 | 18,053 B | B | view · diff |
| git:20260426.d53cc6c | 2026-04-26 | d53cc6c | 18,033 B | B | view |
Audit of the latest version
- fail: No script tag (matched: <script)
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (18053 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
Starting a new one? Use a template for SKILL.md on mdpantry, which passes every one of these checks and says what to change in it.
Source
coco-research/coco · 629 stars · license Apache-2.0 · pushed 2026-11-08 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_7dophjelcpwvdqie GET https://markdownregistry.com/api/v1/resolve?ref=coco-research/coco/OpenAI Apps MCP GET https://markdownregistry.com/api/v1/blob/5d83efa87c6472c877d2e14b5fbe9a6eee8dc242fb2db7a63f8a4b86a5c8c58b
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.