New extension to MCP protocol enables support for interactive UI for MCP hosts. The initial extension specification supports only text/html content. Instead of just returning raw text, MCP servers can now deliver UI in the way that is intended to be visualized, eg. in the form of a HTML chart.
Today we’re introducing the proposal for the MCP Apps Extension (SEP-1865) to standardize support for interactive user interfaces in the Model Context Protocol.This extension addresses one of the most requested features from the MCP community and builds on proven work from MCP-UI and OpenAI Apps SDK – the ability for MCP servers to deliver interactive user interfaces to hosts.MCP Apps Extension introduces a standardized pattern for declaring UI resources, linking them to tools, and enabling bidirectional communication between embedded interfaces and the host application.
Source: MCP Apps: Extending servers with interactive user interfaces | mcp blog