Build Mcp App

Adds interactive UI widgets to MCP servers so tools can render forms, pickers, confirmation dialogs, and dashboards inline in chat instead of returning plain text. Works in both Claude and ChatGPT. The skill covers when to actually use a widget versus just returning text (spoiler: most tools don't need one), how widgets attach to tools via resource URIs, and the iframe runtime mechanics with the App class. Also explains when elicitation covers your use case and you don't need to write any UI code at all. If you're building something where Claude can't reliably infer structured input or the output is inherently visual, this is the path. Otherwise stick with text.

Install to Claude Code

npx -y skills add anthropics/claude-plugins-official --skill build-mcp-app --agent claude-code