SetDefaultAppsX

A native macOS application for setting default apps for file types and URL schemes. Built in Swift with SwiftUI.

SetDefaultAppsX replaces the shell script + swiftDialog approach with a lightweight, dependency-free native app that uses Apple's own NSWorkspace and UTType APIs to query and set default handlers.

Features

• Two-tab interface -- Apps (mail, web, PDF, text, MHL, etc.) and Code (JSON, YAML, TOML, plist, shell, etc.)
• Zero dependencies -- No swiftDialog, no utiluti, no Homebrew. Just macOS frameworks.
• Per-row controls -- See the current default, pick a replacement from a dropdown of all registered apps, and apply individually or in bulk.
• App icons -- Each candidate app is shown with its real icon for quick identification.
• Modern APIs -- Uses NSWorkspace.setDefaultApplication(at:toOpen:) (macOS 12+) for file extensions and LSSetDefaultHandlerForURLScheme for URL schemes.

Requirements

• macOS 13 Ventura or later
• Xcode 16+ (for building from source)

Quick Start

Open in Xcode

open SetDefaultAppsX.xcodeproj

Then press Cmd+R to build and run.

Build from the command line

xcodebuild -project SetDefaultAppsX.xcodeproj -scheme SetDefaultAppsX -configuration Debug build

Supported File Types

Apps Tab

Category	Type	Method
Email	mailto	URL scheme
Web Browser	https	URL scheme
File Transfer	ftp	URL scheme
PDF Documents	.pdf	UTType
Text Files	.txt	UTType
Markdown	.md	UTType
Spreadsheets	.xlsx	UTType
Documents	.docx	UTType
Rich Text	.rtf	UTType
HTML Files	.html	UTType
CSV Files	.csv	UTType
Media Hash List	.mhl	UTType

Code Tab

Category	Type	Method
JSON	.json	UTType
YAML	.yaml	UTType
TOML	.toml	UTType
Property List	.plist	UTType
Mobile Config	.mobileconfig	UTType
XML	.xml	UTType
Shell Scripts	.sh	UTType
Zsh Scripts	.zsh	UTType
Python	.py	UTType
Ruby	.rb	UTType
Swift	.swift	UTType
JavaScript	.js	UTType

Project Structure

SetDefaultAppsX/
├── SetDefaultAppsX.xcodeproj        # Xcode project (generated via xcodegen)
├── project.yml                      # xcodegen spec
├── README.md                        # This file
├── App/
│   ├── Info.plist                   # Bundle ID, version, app metadata
│   ├── SetDefaultAppsX.entitlements # Entitlements
│   └── Assets.xcassets/             # App icon and accent color
├── Sources/
│   ├── SetDefaultAppsXApp.swift     # @main app entry point, About & Help windows
│   ├── ContentView.swift            # Main window UI (tabs, rows, controls)
│   ├── DefaultAppStore.swift        # Core logic: lookup, set, state management
│   └── FileTypeDefinitions.swift    # File type entries and category definitions
└── docs/
    ├── USER_GUIDE.md                # End-user guide
    ├── ARCHITECTURE.md              # Code architecture and design
    └── CHANGELOG.md                 # Version history

How It Works

SetDefaultAppsX uses native macOS APIs exclusively:

1. Discovery -- NSWorkspace.urlsForApplications(toOpen:) finds all apps registered to handle a UTType or URL scheme.
2. Current default -- NSWorkspace.urlForApplication(toOpen:) identifies the current default handler.
3. Setting defaults -- NSWorkspace.setDefaultApplication(at:toOpen:) for file types, LSSetDefaultHandlerForURLScheme for URL schemes.
4. App metadata -- Bundle(url:) and FileManager.displayName(atPath:) resolve display names and bundle identifiers.

No command-line tools are shelled out to. Everything runs in-process.

Origins

SetDefaultAppsX is the native Swift successor to the SetDefaultAppsX.sh shell scripts (v1.0--v2.1) originally created by Scott Kendall. The shell versions used swiftDialog for the GUI and utiluti for UTI management. This native app eliminates those dependencies entirely while providing a richer, faster experience.

See docs/CHANGELOG.md for the full evolution from shell script to native app.

Links

• code.matx.ca
• GitHub -- macvfx/SetDefaultAppsX

Credits

• Scott Kendall -- Original SetDefaultApps shell script
• Bart Reardon -- swiftDialog (used by the shell script predecessors)
• Armin Briegel (scriptingOSX) -- utiluti (used by the shell script predecessors)

License

See the project repository for license information.