URL Scheme Handler Inspector is a desktop URI protocol association viewer, Freedesktop launcher catalog, and interactive RFC 3986 deep-link parser for Linux desktops. An independent Linux alternative inspired by desktop URL protocol viewer utilities, it indexes live x-scheme-handler/* entries across system, Snap, Flatpak, and user .desktop files alongside mimeinfo.cache and mimeapps.list defaults.

Key Features:

• XDG URI Scheme & MIME Association Indexer: Reads x-scheme-handler/* registrations (http, https, file, snap, mailto, ssh, magnet, vscode, and custom app protocols) from host /usr/share/applications, /var/lib/snapd/desktop/applications, user launchers, mimeinfo.cache, and ~/.config/mimeapps.list.
• Desktop Entry & Exec Template Inspector: Displays application names, Desktop IDs, Exec= command-line templates, field code placeholders (%u, %U, %f, %F), categories, and user default overrides.
• RFC 3986 URI Breakdown & Deep-Link Tester: Decomposes any URI into scheme, authority, host, port, path, query key-value pairs, and fragment with live Exec= argv expansion preview and optional desktop dispatch.
• Structured Reports & User Defaults: Supports updating user default scheme associations in ~/.config/mimeapps.list and exporting full catalogs to CSV and JSON.

Disclaimer: This project is an independent open-source tool and is not affiliated with, sponsored by, or endorsed by NirSoft.