Retune

Retune is a React component for adjusting a web app's design visually in the browser, then handing the changes to an AI coding agent to write. Developers click any element and change its spacing, colours, typography, layout, borders and shadows, with every change previewed live on the page. Retune then sends the agent a structured summary rather than a vague description: the component name, selector path, styling approach and exact before-and-after values, with suggested Tailwind classes where they apply. It connects to Claude Code and Cursor over MCP, and can copy the summary to the clipboard for other tools. It works with Next.js, Vite and Remix, and with Tailwind, CSS Modules or plain CSS, and hides itself in production builds. It is installed from npm and suits developers who build interfaces with AI agents and would rather tweak a design by hand than describe it in a prompt. It is free to use under the PolyForm Shield licence.