If you've been building MCP servers, you know the drill: your tool returns JSON, the host renders it as text, and the user squints at a timestamp string. MCP Apps change that — they let your server ship an interactive UI that the host renders in an iframe, right inside the conversation. MCP Apps are built on the Model Context Protocol — an open standard. They're not tied to Claude or any specific AI provider. Any host that implements the MCP Apps specification (Claude Desktop, custom chat clients, or other AI assistants that adopt MCP) can render your UI. You build it once, and it works everywhere MCP is supported. This post walks through building MCP Apps with Angular. We'll start with a single tool, add a second tool with its own UI, and then show how to share code between them without bloating either bundle.…