Model Context Protocol Blog

You’ve built an MCP server that works quite well, but now you’re wondering: How do I add richer UI elements? Custom auth flows? What about domain-specific conventions, like those for finance or healthcare? This is where extensions come in. They let developers layer new capabilities on top of the baseline MCP implementation without touching the core protocol. This allows us to keep things stable while also opening up room to experiment, learn, and build with the community’s needs in mind. ...

MCP’s current spec release came out in November 2025. We haven’t cut a new version since, but the project hasn’t stood still. Over the past year MCP has moved well past its origins as a way to wire up local tools. It now runs in production at companies large and small, powers agent workflows, and is shaped by a growing community through Working Groups, Spec Enhancement Proposals (SEPs), and a formal governance process. None of that is news, but it’s the foundation we’re building on. ...

Today, we’re announcing that MCP Apps are now live as an official MCP extension. Tools can now return interactive UI components that render directly in the conversation: dashboards, forms, visualizations, multi-step workflows, and more. This is the first official MCP extension, and it’s ready for production. We proposed MCP Apps last November, building on the amazing work of MCP-UI and the OpenAI Apps SDK. We were excited to partner with both OpenAI and MCP-UI to create a shared open standard for providing affordances for developers to include UI components in their MCP clients. ...