When tools need UIs

In recent years, modern frameworks have brought backend and frontend together. The client and server environments have different capabilities, but the developer experience feels monolithic.

xmcp started on the server side: that's where MCP began. But things are evolving fast. Our mission is to lower the barrier to entry for developers to build and ship MCP servers without thinking about all the complexity and friction that comes with it.

With the latest MCP apps proposal, we're getting closer to a more unified experience for developers: a standard inspired by MCP-UI and OpenAI's Apps SDK to allow MCP Servers to display interactive UI elements in conversational MCP clients and chatbots.

You shouldn't need to think about complex config or set up. Instead, you can use template literals or React Client Components directly, and it just works.

Always bet on React

It's the most popular JavaScript UI framework out there, massive community, extensive ecosystem, and widespread adoption by major companies. When you already know React, you shouldn't have to learn something new just to return UI from your tools.

We aimed to make it as easy as possible to return React Client components. You only need to convert your handlers from .ts to .tsx. We prioritize speed and keeping the framework lightweight, so for this reason React is an optional peer dependency. You only install it if you need it.

Simplicity over complexity

For client-side components, React is all you need to get up and running quickly and efficiently.

For cases where you need to manage complex interactions between client and server components, like hydration or caching, you can use a framework like Next.js with our adapter that would also allow you to convert Next.js application into compatible MCP apps.

Styling that just works

Under the hood, xmcp compiles using rspack, a fast Rust-based web bundler. When the framework detects JSX, it bundles CSS alongside your JavaScript into the dist directory. Tailwind, CSS Modules, and standard CSS imports work out of the box.

If you want to learn more, you can find additional details and how to get started here.

Looking forward

The protocol and ext-apps specification will continue evolving, and sometimes this natural progression brings additional complexity. Our commitment is to reduce that complexity as much as we can, by actively contributing to the protocol development, carefully following all the latest updates, and ensuring our framework abstracts away unnecessary complications while maintaining full compatibility with the standard.

If you're building your MCP server using our Next.js adapter or React Client Components, we'd love to hear about your experience. Join us on Discord.