MCP Just Got a Native App Platform — Its Default CSP Blocks Everything MCP Apps is the first official extension folded directly into the Model Context Protocol's stable core spec: a tool can now declare an interactive HTML UI — a ui:// resource — that a host renders in a sandboxed iframe instead ...
Source: [Dev.to](https://dev.to/ethan_5b3022150e2c07a4030/mcp-just-got-a-native-app-platform-its-default-csp-blocks-everything-1f3f)