Axiom Location

Location & Maps

You MUST use this skill for ANY location services, mapping, geofencing, or Core Location / MapKit work.

Quick Reference

| Symptom / Task | Reference | |----------------|-----------| | Authorization strategy (When In Use vs Always) | See skills/core-location.md | | Monitoring approach (continuous, significant-change, CLMonitor) | See skills/core-location.md | | Accuracy selection, background location | See skills/core-location.md | | CLLocationUpdate, CLMonitor, CLServiceSession APIs | See skills/core-location-ref.md | | Authorization API patterns, geofencing API | See skills/core-location-ref.md | | Compass heading, heading reference body (headingBody) | See skills/core-location-ref.md (Part 12) | | Location updates never arrive | See skills/core-location-diag.md | | Background location stops working | See skills/core-location-diag.md | | Authorization always denied, geofence failures | See skills/core-location-diag.md | | SwiftUI Map, annotations, markers, clustering | See skills/mapkit.md | | MKMapView vs SwiftUI Map decision | See skills/mapkit.md | | Search, directions, routing | See skills/mapkit.md | | MapKit API: Marker, Annotation, MKLocalSearch, MKDirections | See skills/mapkit-ref.md | | Look Around, MKMapSnapshotter, MKMapItem | See skills/mapkit-ref.md | | Annotations not appearing, region jumping | See skills/mapkit-diag.md | | Clustering not working, search failures | See skills/mapkit-diag.md | | Overlay rendering, user location not showing | See skills/mapkit-diag.md |

Decision Tree

digraph location {
    start [label="Location / Maps task" shape=ellipse];
    domain [label="Core Location or MapKit?" shape=diamond];
    cl_type [label="Need what?" shape=diamond];
    mk_type [label="Need what?" shape=diamond];

    start -> domain;

    domain -> cl_type [label="Core Location"];
    domain -> mk_type [label="MapKit / Maps"];

    cl_type -> "skills/core-location.md" [label="authorization, monitoring\nstrategy, accuracy,\nbackground location"];
    cl_type -> "skills/core-location-ref.md" [label="API syntax\n(CLLocationUpdate,\nCLMonitor, CLServiceSession)"];
    cl_type -> "skills/core-location-diag.md" [label="something broken\n(no updates, denied,\ngeofence not firing)"];

    mk_type -> "skills/mapkit.md" [label="patterns, decisions\n(SwiftUI Map vs MKMapView,\nannotations, search)"];
    mk_type -> "skills/mapkit-ref.md" [label="API syntax\n(Marker, Annotation,\nMKLocalSearch, MKDirections)"];
    mk_type -> "skills/mapkit-diag.md" [label="something broken\n(annotations missing,\nregion jumping, clustering)"];
}

1. Authorization strategy, monitoring approach, accuracy? → skills/core-location.md

1a. Need specific API syntax (CLLocationUpdate, CLMonitor, CLServiceSession)? → skills/core-location-ref.md 1b. Location not working? → skills/core-location-diag.md

1. Adding a map, annotations, search, directions? → skills/mapkit.md

2a. Need specific MapKit API syntax (Marker, MKLocalSearch, MKDirections)? → skills/mapkit-ref.md 2b. Map display broken? → skills/mapkit-diag.md

1. Location draining battery? → See axiom-performance (skills/energy.md)
2. Background task scheduling for location? → See axiom-integration
3. Privacy manifest for location? → See axiom-integration

Conflict Resolution

location vs axiom-performance: When location is draining battery:

1. Try location FIRST — Excessive accuracy or continuous updates are the #1 cause. skills/core-location.md covers accuracy selection and monitoring strategy.
2. Only use axiom-performance if location settings are already correct — Profile after ruling out obvious over-tracking.

location vs axiom-integration: When implementing background location:

• Background location configuration (Info.plist, capabilities, CLServiceSession) → use location
• BGTaskScheduler for periodic location processing → use axiom-integration

location vs axiom-data: When storing or syncing location data:

• Getting location updates, geofencing → use location
• Persisting location history, CloudKit sync → use axiom-data

location vs axiom-build: When location permissions fail in simulator:

• Authorization dialogs, Info.plist keys → use location (skills/core-location-diag.md)
• Simulator GPS simulation, simctl location → use axiom-build

Critical Patterns

Core Location (skills/core-location.md):

• Authorization escalation strategy (When In Use first, Always later)
• Monitoring decision tree (continuous vs significant-change vs CLMonitor)
• Accuracy selection with battery impact
• Background location configuration
• Anti-patterns with time costs (premature Always authorization, unnecessary continuous updates)

Core Location API (skills/core-location-ref.md):

• CLLocationUpdate AsyncSequence (iOS 17+)
• CLMonitor condition-based geofencing (iOS 17+)
• CLServiceSession declarative authorization (iOS 18+)
• Authorization API patterns, background mode configuration

Core Location Diagnostics (skills/core-location-diag.md):

• Location updates never arrive
• Background location stops working
• Authorization always denied
• Geofence events not triggering
• Location accuracy unexpectedly poor

MapKit (skills/mapkit.md):

• SwiftUI Map vs MKMapView decision tree
• Annotation patterns (Marker, custom Annotation)
• Search (MKLocalSearch, autocomplete)
• Directions and routing
• Anti-patterns (annotations in view body, no view reuse, setRegion loops)

MapKit API (skills/mapkit-ref.md):

• SwiftUI Map API (MapCameraPosition, content builders, controls)
• MKMapView delegate patterns
• MKLocalSearch, MKDirections
• Look Around, MKMapSnapshotter
• Clustering configuration

MapKit Diagnostics (skills/mapkit-diag.md):

• Annotations not appearing (lat/lng swapped, missing delegate)
• Map region jumping/looping (updateUIView guard)
• Clustering not working (missing clusteringIdentifier)
• Search returning no results (resultTypes, region bias)
• Overlay rendering failures

Anti-Rationalization

| Thought | Reality | |---------|---------| | "Just request Always authorization upfront" | 30-60% denial rate. Request When In Use first, escalate later. skills/core-location.md covers the strategy. | | "Continuous updates are fine for my use case" | Continuous updates drain battery even when the app doesn't need sub-second location. Use significant-change or CLMonitor. | | "I'll use MKMapView, it's more flexible" | SwiftUI Map covers most use cases since iOS 17. MKMapView means UIViewRepresentable boilerplate. skills/mapkit.md has the decision tree. | | "Annotations in the view body is fine for a few items" | Annotations recreate on every view update. Even 50 items cause hitches. Move to model with @State or @Observable. | | "I know how geofencing works" | CLMonitor (iOS 17+) replaces legacy region monitoring with conditions. The API changed significantly. | | "Background location just needs the capability" | It needs Info.plist keys, capability, CLServiceSession (iOS 18+), AND correct authorization level. Missing any one silently fails. | | "I'll handle location errors later" | Authorization denial is not an error — it's the default state. Handle it from the start. |

Example Invocations

User: "How do I request location permissions?" → Read: skills/core-location.md

User: "What's the CLLocationUpdate API?" → Read: skills/core-location-ref.md

User: "My location updates never arrive" → Read: skills/core-location-diag.md

User: "How do I add a map with pins?" → Read: skills/mapkit.md

User: "What's the SwiftUI Map API?" → Read: skills/mapkit-ref.md

User: "My annotations aren't showing on the map" → Read: skills/mapkit-diag.md

User: "How do I implement geofencing?" → Read: skills/core-location.md then skills/core-location-ref.md

User: "Location is draining battery" → Read: skills/core-location.md, then See axiom-performance (skills/energy.md)

User: "How do I add search to my map?" → Read: skills/mapkit.md then skills/mapkit-ref.md

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: CharlesWiltgen
• Source: CharlesWiltgen/Axiom
• License: MIT
• Homepage: https://charleswiltgen.github.io/Axiom/

Install and usage instructions live in the source repository linked above.