Frequently Asked Questions

sunpeak is an MCP App framework and ChatGPT App framework. sunpeak enables developers to quickly build, test, and ship MCP Apps for ChatGPT, Claude, and other AI hosts, all from your local machine. sunpeak provides strongly typed APIs, a ChatGPT App inspector for testing, and production-ready UI components.

You can create a new sunpeak project by running npx sunpeak new. This will scaffold a complete MCP App project with all necessary dependencies, build tools, and testing infrastructure. For existing React projects, you can install sunpeak as a dependency using npm or your preferred package manager.

The MCP (Model Context Protocol) server provides your MCP App content to AI hosts like ChatGPT and Claude. It makes tools, resources, and prompts available that can be used by the AI host. sunpeak includes a built-in MCP server that you can run locally using pnpm dev for testing and development with mock data.

Yes! sunpeak provides an ChatGPT App Inspector — a React component that replicates the ChatGPT and MCP App environment. This allows you to test your app locally before deploying it. You can also use the built-in MCP server with mock data to test your local MCP App in the real ChatGPT.

sunpeak includes production-ready UI components for building MCP Apps. Components follow ChatGPT design guidelines and work across MCP-compatible AI hosts.

sunpeak provides 19+ typed React hooks for interacting with the MCP App runtime. These hooks include host context, theme detection, display modes, tool data, action hooks, and state management. These hooks make it easy to build MCP Apps that work across ChatGPT, Claude, and other AI hosts. See the MCP Apps React hooks reference.

Run pnpm build to create production-ready bundles, then pnpm start to launch a production MCP server. For custom setups (Express, Cloudflare Workers, etc.), use the createMcpHandler or createHandler APIs from sunpeak/mcp. See the deployment guide.

Yes, sunpeak includes a built-in testing framework. Run pnpm test to execute both unit and e2e tests. Use pnpm test:unit or pnpm test:e2e to run them separately, pnpm test:visual for visual regression tests, pnpm test:live for live host tests, or pnpm test:eval for multi-model evals that test tool calling across GPT-4o, Claude, Gemini, and other LLMs. The framework provides testing utilities and examples to help you write comprehensive tests for your MCP Apps and ChatGPT Apps in all tool, runtime, and conversation states.

MCP Apps are interactive applications built on the Model Context Protocol (MCP) that run inside AI hosts. ChatGPT Apps are MCP Apps that run specifically inside ChatGPT, with some ChatGPT-specific features. Your app UIs are MCP Resources that AI hosts like ChatGPT and Claude render in conversations. sunpeak builds MCP Apps that work across all compatible hosts. Learn more about the MCP App framework or the ChatGPT App framework.

The complete sunpeak documentation is available at sunpeak.ai/docs. For MCP App-specific APIs and protocol details, see the MCP Apps technical documentation. It includes quickstart guides, API references, integration instructions, and deployment guides to help you build MCP Apps and ChatGPT Apps.

Yes! sunpeak is open source and available on GitHub at github.com/sunpeak-AI/sunpeak. You can also find the package on npm at npmjs.com/package/sunpeak.

sunpeak provides several CLI commands: npx sunpeak new for creating MCP App projects, pnpm dev for running the development server (web and MCP), pnpm build for production builds, and pnpm start for running a production MCP server.