FAQs
Frequently asked questions
| Product | moonpeak |
|---|---|
| Category | MCP App framework, MCP testing framework, MCP App inspector |
| License | MIT |
| Package | moonpeak on npm |
| Includes | App framework, CLI, inspector, test runner, Playwright fixtures, evals |
| Built on | MCP Apps SDK, MCP TypeScript SDK v2, React, Vite |
What is an MCP App?
An MCP tool that comes with a UI. The tool declares a ui:// resource, the host fetches that HTML and renders it in a sandboxed frame next to the conversation, and the two talk over a small postMessage protocol defined by the MCP Apps extension.
What is an MCP App framework?
A toolkit that turns tools and React components into a working MCP server with UI resources: discovery, bundling each View into one HTML file, host metadata, a local host to look at it and a production server. moonpeak is one.
Is moonpeak a ChatGPT App framework?
Yes. ChatGPT Apps are MCP Apps. moonpeak resources carry both the MCP Apps metadata and the older openai/* keys, and moonpeak/chatgpt exposes widget state, file upload and modals when a View runs inside ChatGPT.
Is moonpeak a Claude connector framework?
Yes. Deploy the server over HTTPS and add https://your-domain/mcp as a custom connector in Claude. moonpeak/claude has Claude-specific helpers.
Do I need a ChatGPT or Claude account to develop?
No. The inspector replicates both hosts locally, including theme, display modes and the bridge calls a View can make. You only need a host account to try the deployed app there.
Can I test a server that isn't built with moonpeak?
Yes. moonpeak inspect --server and moonpeak test --server work with any MCP server over Streamable HTTP, written in any language. --header adds auth.
Does it run in CI?
Yes. moonpeak test runs in-process in seconds (most of it is building each View). --e2e and --visual need Chromium from Playwright. --eval needs provider keys. The repository's own CI runs all of it on Linux.
What do evals need?
Provider keys (ANTHROPIC_API_KEY, OPENAI_API_KEY) and the matching SDK in your project. Everything else runs offline.
How do I deploy?
moonpeak build then moonpeak start, or import createHandler from moonpeak/server and mount it on any runtime that speaks Fetch.
Is there a live demo?
Yes. The starter app runs at https://moonpeak-ai.com/mcp. Add it as a connector in Claude or an app in ChatGPT developer mode, or inspect it with npx moonpeak inspect --server https://moonpeak-ai.com/mcp.
Is it free?
Free and MIT licensed. No account and no telemetry.