to-userscript: Powerful CLI for Converting Browser Extensions to Standalone Userscripts

to-userscript is a command-line tool that transforms Chrome or Firefox extensions into standalone .user.js files runnable in any userscript manager. It handles various sources: Chrome Web Store, Firefox Add-ons, local directories, and archive files. It cleverly replaces common WebExtension APIs, embeds CSS, images, and other resources, and emulates background scripts and internationalization. Installation is straightforward via npm, pnpm, or bun.