Core Location

Implementation patterns for Core Location. Covers authorization strategy, monitoring approach selection, accuracy optimization, and background location setup.

When to Use This Skill

Use this skill when you're:

• Choosing between When In Use vs Always authorization
• Deciding on monitoring approach (continuous, significant-change, CLMonitor)
• Implementing geofencing or region monitoring
• Setting up background location updates
• Reviewing location code for anti-patterns

Note: For API details and code examples, see core-location-ref. For troubleshooting, see core-location-diag.

Example Prompts

Questions you can ask Claude that will draw from this skill:

• "Should I use When In Use or Always authorization?"
• "How should I implement geofencing in my app?"
• "What's the best way to track user location in background?"
• "Why is my location code draining battery?"
• "How do I upgrade from When In Use to Always authorization?"
• "What accuracy level should I use for a store finder?"
• "How do I handle location authorization denial gracefully?"

What's Covered

Anti-Patterns Prevented

• Premature Always authorization (30-60% denial rate)
• Continuous updates for geofencing (10x battery drain vs CLMonitor)
• Ignoring stationary detection (wasted battery)
• No graceful denial handling
• Wrong accuracy for use case
• Not stopping updates when done
• Ignoring CLServiceSession (iOS 18+)

Decision Trees

• Authorization strategy (When In Use vs Always, upgrade flow)
• Monitoring strategy (continuous vs significant-change vs CLMonitor)
• Accuracy selection (navigation vs fitness vs store finder)

Pressure Scenarios

• "Just use Always authorization" pushback
• "Location isn't working in background" debugging
• "Geofence events aren't firing" production issues

Checklists

• Pre-release location checklist
• Background location setup checklist

Key Pattern

Progressive Authorization (Recommended)

// Start minimal - When In Use
let baseSession = CLServiceSession(authorization: .whenInUse)

// Later, when user creates a location reminder:
let alwaysSession = CLServiceSession(authorization: .always)

// For features needing full accuracy:
let navSession = CLServiceSession(
    authorization: .whenInUse,
    fullAccuracyPurposeKey: "Navigation"
)

Why: Starting with Always authorization has 30-60% denial rate. Progressive upgrade when user understands value has 5-10% denial rate.

Documentation Scope

This page documents the axiom-core-location skill—implementation patterns and decision frameworks Claude uses when helping you design location features.

For API reference: See core-location-ref for CLLocationUpdate, CLMonitor, CLServiceSession APIs.

For troubleshooting: See core-location-diag for debugging location issues.

Related

• core-location-ref — Complete API reference for modern Core Location
• core-location-diag — Symptom-based troubleshooting
• energy — Location as battery subsystem

Resources

WWDC: 2023-10180, 2023-10147, 2024-10212

Docs: /corelocation, /corelocation/clmonitor, /corelocation/cllocationupdate