Handle Extension

Handle provides visual tools that let developers and designers modify a web app’s user interface directly in the browser and then propagate those changes into the underlying codebase. Through a Chrome extension users can select page elements, tweak styling and layout, and send the updates to a coding agent that applies them to the source files. The workflow is organized into three stages—Create, Refine, and Land—allowing iterative exploration with existing agents such as Claude Code, Codex, Cursor, GitHub Copilot, Gemini CLI, Rovo Dev, and Windsurf.

The extension works alongside a local development server; invoking “/handle” opens the visual interface without requiring a separate environment. For deeper design work, a macOS desktop application called Handle Studio offers a dedicated workspace with advanced tooling, still communicating with the same coding agents to commit UI changes. Both the extension and the desktop app are distributed as open‑source software, installable via an npx command or from the project’s GitHub repository.