Instagui turns any CLI tool into a web GUI instantly
Instagui runs via npx and parses a CLI's --help output with AI to auto-generate a local web form, letting you run tools like ffmpeg without memorizing flags.
Instagui is an open-source CLI utility that converts any command-line tool into a local web form without requiring any changes to the tool itself. Running npx instagui ffmpeg captures the tool's --help output, sends it to the Claude API to produce a structured schema, and renders that schema as a browser-based form with appropriate inputs like checkboxes, dropdowns, and number fields. Before executing, it always displays the exact command that will run, and execution happens via spawn with an argument array rather than a shell string, eliminating injection risk from special characters.
To keep costs down, instagui resolves schemas through a tiered fallback: user-supplied overrides, a local cache, bundled schemas for ffmpeg/yt-dlp/pandoc (free, no API key needed), and finally a fresh Claude API extraction only when necessary. Once a tool has been resolved once, every subsequent launch is instant and free. On the security side, the server binds only to 127.0.0.1, enforces Origin-header checks against CSRF, and never logs or exposes the API key.
The project currently excludes interactive TUI programs, subcommand trees like git commit, and native file pickers; it requires Node.js 22+ and is released under MIT. It offers a practical bridge for developers who want to explore CLI flags visually instead of digging through man pages, and for teams looking to make dense command-line tools more approachable.