macOS Application Configuration Discovery

This skill provides knowledge and methodology for discovering where macOS applications store their configuration files, preferences, and settings. It enables effective contribution to MacInventory's hints database.

Overview

macOS applications store their configuration in predictable locations based on app type, development era, and sandboxing status. Understanding these patterns enables systematic discovery of config paths for any application.

The Three-Tier Discovery System

MacInventory uses a three-tier approach to find application configurations:

1. Tier 1 - Hints Database: Curated YAML entries with verified config paths (highest trust)
2. Tier 2 - Conventions: Automatic scanning of standard macOS locations
3. Tier 3 - LLM Research: Web search and intelligent discovery for unknown apps

This skill supports all three tiers by providing the knowledge needed to research and document application configurations.

Standard macOS Configuration Locations

Primary Locations (Check First)

Location	Purpose	Typical Contents
~/Library/Application Support/	Modern app data	Databases, caches, configs
~/Library/Preferences/	Preference plists	.plist settings files
~/.config/	XDG standard	CLI tool configs
~/Library/Containers/	Sandboxed apps	App-specific storage

Secondary Locations (App-Specific)

Location	Purpose	Example Apps
~/.appname/	Dotfile configs	CLI tools, dev tools
~/Library/Group Containers/	Shared app data	iCloud-enabled apps
~/Library/Caches/	Cache data	All apps (usually exclude)
~/Library/Saved Application State/	Window states	GUI apps

Environment-Specific Paths

For detailed information on each location and its typical contents, see references/common-paths.md.

App-Hints.yaml Entry Format

To add an application to the hints database, create a YAML entry with this structure:

app-name:
  bundle_id: com.developer.AppName  # Required (null for CLI tools)
  install_method: cask              # Required: cask | formula | mas | dmg | system
  configuration_files:              # Paths relative to $HOME (no ~/ prefix)
    - Library/Application Support/AppName/
    - Library/Preferences/com.developer.AppName.plist
  xdg_configuration_files:          # Paths relative to ~/.config (optional)
    - appname/config.yaml
  exclude_files:                    # Files/dirs to skip during backup
    - "*.log"
    - "Cache/"
    - "*.tmp"
  notes: |
    Optional notes about the app's config behavior,
    special considerations, or discovery methodology.

Field Descriptions

• bundle_id (required): macOS bundle identifier - get with osascript -e 'id of app "AppName"'. Use null for CLI tools.
• install_method (required): How the app is installed - cask | formula | mas | dmg | system
• configuration_files: Paths relative to $HOME (no ~/ prefix). For files like ~/Library/...
• xdg_configuration_files: Paths relative to $XDG_CONFIG_HOME (default ~/.config/). For files like ~/.config/appname/
• exclude_files: Glob patterns for files/dirs to skip during backup
• notes: Optional context about the app or special handling needed

IMPORTANT: Paths are RELATIVE - use Library/Application Support/App/ not ~/Library/Application Support/App/

For a complete template with all optional fields, see examples/hints-entry-template.yaml.

Discovery Methodology

Quick Discovery Checklist

When researching where an app stores its configuration:

1. Check standard locations first - Most apps use conventional paths
2. Search for the app's bundle ID - Find with: osascript -e 'id of app "AppName"'
3. Look in Application Support - Most modern apps: ls ~/Library/Application\ Support/ | grep -i appname
4. Check Preferences - Traditional plist: ls ~/Library/Preferences/ | grep -i appname
5. Try XDG config - CLI tools: ls ~/.config/ | grep -i appname
6. Check for dotfiles - Some tools: ls -la ~/ | grep -i appname

Research Resources

When standard locations don't yield results:

• Official documentation: Check the app's docs/FAQ for "where are settings stored"
• GitHub repository: For open source apps, check README and code
• Stack Overflow: Search "[AppName] config file location mac"
• Reddit/Forums: Community discussions often reveal hidden paths

For detailed research methodology, see references/research-methodology.md.

Configuration File Patterns

Different types of apps follow different configuration patterns:

GUI Applications

Modern macOS GUI apps typically use:

• ~/Library/Application Support/AppName/ for data and complex configs
• ~/Library/Preferences/com.developer.AppName.plist for simple preferences
• Sandboxed apps: ~/Library/Containers/com.developer.AppName/

CLI Tools

Command-line tools commonly use:

• ~/.config/toolname/ (XDG standard)
• ~/.toolname or ~/.toolnamerc (traditional dotfiles)
• ~/.toolname/config.yaml or similar

Development Tools

IDEs and dev tools often have complex configurations:

• Settings, keybindings, snippets (usually JSON or XML)
• Extensions/plugins directory
• Project-specific vs global settings

For comprehensive patterns by app category, see references/settings-patterns.md.

What to Exclude from Backup

Not everything in an app's directory should be backed up. Exclude:

Always Exclude

• Caches: Cache/, Caches/, *.cache
• Logs: *.log, Logs/, log/
• Temporary files: *.tmp, temp/, Temp/
• Generated data: GPUCache/, Code Cache/
• Large databases: *.sqlite (unless settings), *.db

Usually Exclude

• Updates: Updates/, *.download
• App backups: Backups/, backup/
• Media caches: MediaCache/, ImageCache/

Never Backup

• SSH keys: id_rsa, id_ed25519, etc.
• Certificates: *.pem, *.key (non-config)
• OAuth tokens: If stored in plaintext files

Validation Process

Before adding an entry to the hints database:

1. Verify paths exist: Use Glob to confirm each path is present on the system
2. Check file contents: Ensure files are configuration, not caches/data
3. Test exclude patterns: Verify patterns correctly filter non-config files
4. Validate YAML syntax: Use the validate-hints.py script

# Validate hints database (use installed plugin path)
PLUGIN_PATH=~/.claude/plugins/macinventory@MacInventory
python3 $PLUGIN_PATH/skills/macos-discovery/scripts/validate-hints.py \
    $PLUGIN_PATH/data/app-hints.yaml

Utility Scripts

This skill includes utility scripts in scripts/:

• validate-hints.py: Validate app-hints.yaml entries for correctness
• test-security-patterns.py: Test security pattern matching

Additional Resources

Reference Files

For detailed information beyond this overview:

• references/common-paths.md - Complete guide to macOS config locations
• references/settings-patterns.md - Config patterns by application type
• references/research-methodology.md - How to research unknown apps

Examples

• examples/hints-entry-template.yaml - Complete template for new entries

Integration with MacInventory

This skill supports:

1. Adding apps to hints database - Research and create YAML entries
2. Tier 3 discovery - Used by app-discovery agent for unknown apps
3. Validation - Verify discovered paths are actual configurations
4. Documentation - Understanding macOS config conventions