axiom-mapkit-ref

name	axiom-mapkit-ref
description	MapKit API reference — SwiftUI Map, MKMapView, Marker, Annotation, MKLocalSearch, MKDirections, Look Around, MKMapSnapshotter, clustering, overlays, GeoToolbox PlaceDescriptor, geocoding
license	MIT
metadata	{"version":"1.0.0","last-updated":"2026-02-26"}

MapKit API Reference

Complete MapKit API reference for iOS development. Covers both SwiftUI Map (iOS 17+) and MKMapView (UIKit).

Related Skills

• axiom-mapkit — Decision trees, anti-patterns, pressure scenarios
• axiom-mapkit-diag — Symptom-based troubleshooting

---

Part 1: Modern API Overview

Feature	SwiftUI Map (iOS 17+)	MKMapView
Declaration	Map(position:) { content }	MKMapView()
Camera control	MapCameraPosition binding	setRegion(_:animated:)
Annotations	Marker, Annotation in content	addAnnotation(_:) + delegate
Overlays	MapCircle, MapPolyline, MapPolygon	addOverlay(_:) + renderer delegate
User location	UserAnnotation()	showsUserLocation = true
Selection	.mapSelection($selection)	delegate didSelect
Controls	.mapControls { }	showsCompass, showsScale
Interaction modes	.mapInteractionModes([])	delegate methods
Clustering	Built-in via .mapItemClusteringIdentifier	MKClusterAnnotation

---

Part 2: SwiftUI Map API

Basic Map

@State private var cameraPosition: MapCameraPosition = .automatic

Map(position: $cameraPosition) {
    Marker("Home", coordinate: homeCoord)
    Annotation("Custom", coordinate: coord) {
        Image(systemName: "star.fill")
            .foregroundStyle(.yellow)
            .padding(4)
            .background(.blue, in: Circle())
    }
    UserAnnotation()
    MapCircle(center: coord, radius: 500)
        .foregroundStyle(.blue.opacity(0.3))
    MapPolyline(coordinates: routeCoords)
        .stroke(.blue, lineWidth: 3)
}
.mapStyle(.standard(elevation: .realistic))
.mapControls {
    MapUserLocationButton()
    MapCompass()
    MapScaleView()
}

MapCameraPosition

Controls where the camera is positioned:

// System manages camera to show all content
.automatic

// Specific region
.region(MKCoordinateRegion(
    center: CLLocationCoordinate2D(latitude: 37.7749, longitude: -122.4194),
    span: MKCoordinateSpan(latitudeDelta: 0.05, longitudeDelta: 0.05)
))

// Specific camera with pitch and heading
.camera(MapCamera(
    centerCoordinate: coordinate,
    distance: 1000,    // meters from center
    heading: 90,       // degrees from north
    pitch: 60          // degrees from vertical (0 = top-down)
))

// Follow user location
.userLocation(followsHeading: true, fallback: .automatic)

// Show specific item
.item(mapItem)

// Show specific rect
.rect(MKMapRect(...))

Programmatic Camera Changes

// Animate to new position
withAnimation {
    cameraPosition = .region(newRegion)
}

// Keyframe animation (iOS 17+)
Map(position: $cameraPosition)
    .mapCameraKeyframeAnimator(trigger: flyToTrigger) { initialCamera in
        KeyframeTrack(\.centerCoordinate) {
            LinearKeyframe(destination, duration: 2.0)
        }
        KeyframeTrack(\.distance) {
            CubicKeyframe(5000, duration: 1.0)
            CubicKeyframe(1000, duration: 1.0)
        }
    }

Map Selection

@State private var selectedItem: MKMapItem?

Map(position: $cameraPosition, selection: $selectedItem) {
    ForEach(mapItems, id: \.self) { item in
        Marker(item: item)
    }
}
.onChange(of: selectedItem) { _, newItem in
    if let newItem {
        // Handle selection
    }
}

Camera Change Callback

Map(position: $cameraPosition) { ... }
    .onMapCameraChange { context in
        // context.region — visible MKCoordinateRegion
        // context.camera — current MapCamera
        // context.rect — visible MKMapRect
        fetchAnnotations(in: context.region)
    }
    .onMapCameraChange(frequency: .continuous) { context in
        // Called during gesture (not just at end)
    }

Map Styles

.mapStyle(.standard)                              // Default
.mapStyle(.standard(elevation: .realistic))        // 3D buildings
.mapStyle(.standard(emphasis: .muted))             // Muted colors
.mapStyle(.standard(pointsOfInterest: .including([.restaurant, .cafe])))
.mapStyle(.imagery)                                // Satellite
.mapStyle(.imagery(elevation: .realistic))         // 3D satellite
.mapStyle(.hybrid)                                 // Satellite + labels
.mapStyle(.hybrid(elevation: .realistic))          // 3D hybrid

Interaction Modes

// Allow all interactions (default)
.mapInteractionModes(.all)

// Read-only map (no interaction)
.mapInteractionModes([])

// Pan only, no zoom
.mapInteractionModes([.pan])

// Pan and zoom, no rotate/pitch
.mapInteractionModes([.pan, .zoom])

---

Part 3: Map Content

Marker

System-styled map marker with callout:

// Basic marker
Marker("Coffee Shop", coordinate: coord)

// With system image
Marker("Coffee Shop", systemImage: "cup.and.saucer.fill", coordinate: coord)

// With monogram (2 characters max)
Marker("Coffee Shop", monogram: Text("CS"), coordinate: coord)

// Color
Marker("Coffee Shop", coordinate: coord)
    .tint(.brown)

// From MKMapItem
Marker(item: mapItem)

Annotation

Fully custom view at a coordinate:

Annotation("Custom Pin", coordinate: coord) {
    VStack {
        Image(systemName: "mappin.circle.fill")
            .font(.title)
            .foregroundStyle(.red)
        Text("Here")
            .font(.caption)
    }
}

// Anchor point (default is bottom center)
Annotation("Pin", coordinate: coord, anchor: .center) {
    Circle()
        .fill(.blue)
        .frame(width: 20, height: 20)
}

UserAnnotation

Current user location indicator:

UserAnnotation()

// Custom appearance
UserAnnotation(anchor: .center) {
    Image(systemName: "location.circle.fill")
        .foregroundStyle(.blue)
}

Shape Overlays

// Circle
MapCircle(center: coord, radius: 1000)  // radius in meters
    .foregroundStyle(.blue.opacity(0.2))
    .stroke(.blue, lineWidth: 2)

// Polygon
MapPolygon(coordinates: polygonCoords)
    .foregroundStyle(.green.opacity(0.3))
    .stroke(.green, lineWidth: 2)

// Polyline
MapPolyline(coordinates: routeCoords)
    .stroke(.blue, lineWidth: 4)

// From MKRoute
MapPolyline(route.polyline)
    .stroke(.blue, lineWidth: 5)

Clustering

ForEach(locations) { location in
    Marker(location.name, coordinate: location.coordinate)
        .tag(location.id)
}
.mapItemClusteringIdentifier("locations")

---

Part 4: MKMapView Lifecycle and Delegates

Creating MKMapView in SwiftUI

struct MapViewWrapper: UIViewRepresentable {
    @Binding var region: MKCoordinateRegion
    let annotations: [MKAnnotation]

    func makeUIView(context: Context) -> MKMapView {
        let mapView = MKMapView()
        mapView.delegate = context.coordinator
        mapView.showsUserLocation = true
        mapView.register(
            MKMarkerAnnotationView.self,
            forAnnotationViewWithReuseIdentifier: "marker"
        )
        return mapView
    }

    func updateUIView(_ mapView: MKMapView, context: Context) {
        // Guard against infinite loops
        if !regionsAreEqual(mapView.region, region) {
            mapView.setRegion(region, animated: true)
        }

        // Diff annotations instead of removing all
        let current = Set(mapView.annotations.compactMap { $0 as? MyAnnotation })
        let desired = Set(annotations.compactMap { $0 as? MyAnnotation })
         toAdd  desired.subtracting(current)
         toRemove  current.subtracting(desired)
        mapView.addAnnotations((toAdd))
        mapView.removeAnnotations((toRemove))
    }

     () ->  {
        ()
    }

      ( : , : ) {
        mapView.removeAnnotations(mapView.annotations)
        mapView.removeOverlays(mapView.overlays)
    }
}

Key MKMapViewDelegate Methods

class Coordinator: NSObject, MKMapViewDelegate {
    var parent: MapViewWrapper

    init(_ parent: MapViewWrapper) {
        self.parent = parent
    }

    // Annotation view customization
    func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -> MKAnnotationView? {
        guard !(annotation is MKUserLocation) else { return nil }  // Use default for user

        let view = mapView.dequeueReusableAnnotationView(
            withIdentifier: "marker",
            for: annotation
        ) as! MKMarkerAnnotationView
        view.markerTintColor = .systemRed
        view.glyphImage = UIImage(systemName: "mappin")
        view.clusteringIdentifier = "poi"
        view.canShowCallout = true
        return view
    }

    // Overlay rendering
    func mapView(_ mapView: ,  : ) ->  {
          circle  overlay   {
             renderer  (circle: circle)
            renderer.fillColor  .systemBlue.withAlphaComponent()
            renderer.strokeColor  .systemBlue
            renderer.lineWidth  
             renderer
        }
          polyline  overlay   {
             renderer  (polyline: polyline)
            renderer.strokeColor  .systemBlue
            renderer.lineWidth  
             renderer
        }
          polygon  overlay   {
             renderer  (polygon: polygon)
            renderer.fillColor  .systemGreen.withAlphaComponent()
            renderer.strokeColor  .systemGreen
            renderer.lineWidth  
             renderer
        }
         (overlay: overlay)
    }

    
     ( : ,  : ) {
        parent.region  mapView.region
    }

    
     ( : ,  : ) {
        
    }

    
     (
         : ,
         : []
    ) ->  {
        (memberAnnotations: memberAnnotations)
    }
}

---

Part 5: Annotation Types and Customization

MKMarkerAnnotationView (iOS 11+)

Balloon-shaped marker with glyph:

let view = MKMarkerAnnotationView(annotation: annotation, reuseIdentifier: "marker")
view.markerTintColor = .systemPurple
view.glyphImage = UIImage(systemName: "star.fill")
view.glyphText = "A"                    // Text glyph (overrides image)
view.displayPriority = .required        // Always visible
view.clusteringIdentifier = "category"  // Enable clustering
view.canShowCallout = true
view.titleVisibility = .adaptive        // Show title based on space
view.subtitleVisibility = .hidden

MKAnnotationView

Fully custom annotation view:

let view = MKAnnotationView(annotation: annotation, reuseIdentifier: "custom")
view.image = UIImage(named: "custom-pin")
view.centerOffset = CGPoint(x: 0, y: -view.image!.size.height / 2)
view.canShowCallout = true
view.leftCalloutAccessoryView = UIImageView(image: thumbnail)
view.rightCalloutAccessoryView = UIButton(type: .detailDisclosure)

Custom Callout

func mapView(
    _ mapView: MKMapView,
    annotationView view: MKAnnotationView,
    calloutAccessoryControlTapped control: UIControl
) {
    guard let annotation = view.annotation as? MyAnnotation else { return }
    // Navigate to detail view
}

Annotation View Reuse

Always use dequeueReusableAnnotationView(withIdentifier:for:):

// Register in makeUIView (once)
mapView.register(MKMarkerAnnotationView.self, forAnnotationViewWithReuseIdentifier: "marker")

// Dequeue in delegate (every time)
func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -> MKAnnotationView? {
    let view = mapView.dequeueReusableAnnotationView(withIdentifier: "marker", for: annotation)
    // Configure...
    return view
}

Without reuse: 1000 annotations = 1000 views in memory. With reuse: ~20-30 views recycled as user scrolls.

---

Part 6: MKLocalSearch and MKLocalSearchCompleter

MKLocalSearchCompleter — Real-Time Autocomplete

let completer = MKLocalSearchCompleter()
completer.delegate = self
completer.resultTypes = [.pointOfInterest, .address]
completer.region = visibleMapRegion    // Bias results to visible area

// Update on each keystroke
completer.queryFragment = "coffee"

// Delegate receives results
func completerDidUpdateResults(_ completer: MKLocalSearchCompleter) {
    let results = completer.results  // [MKLocalSearchCompletion]
    for result in results {
        // result.title — "Starbucks"
        // result.subtitle — "123 Main St, San Francisco, CA"
        // result.titleHighlightRanges — Ranges matching query
    }
}

func completer(_ completer: MKLocalSearchCompleter, didFailWithError error: Error) {
    // Network error, rate limit, etc.
}

MKLocalSearch — Full Search

// From autocomplete completion
let request = MKLocalSearch.Request(completion: selectedCompletion)

// From natural language
let request = MKLocalSearch.Request()
request.naturalLanguageQuery = "coffee shops"
request.region = mapRegion                        // Bias results
request.resultTypes = .pointOfInterest            // Filter type
request.pointOfInterestFilter = MKPointOfInterestFilter(
    including: [.cafe, .restaurant]
)

let search = MKLocalSearch(request: request)
let response = try await search.start()

for item in response.mapItems {
    // item.name — "Starbucks"
    // item.placemark — MKPlacemark with address
    // item.placemark.coordinate — CLLocationCoordinate2D
    // item.phoneNumber — optional phone
    // item.url — optional website
    // item.pointOfInterestCategory — .cafe, .restaurant, etc.
}

Result Types

// Filter what kind of results to return
request.resultTypes = .address           // Street addresses only
request.resultTypes = .pointOfInterest   // Businesses, landmarks
request.resultTypes = .physicalFeature   // Mountains, lakes, parks
request.resultTypes = .query             // Suggested search queries (iOS 18+)
request.resultTypes = [.pointOfInterest, .address]  // Multiple types

Rate Limiting

• MKLocalSearchCompleter handles its own throttling — safe to call on every keystroke
• MKLocalSearch — Apple rate-limits these; don't fire more than ~1/second
• If rate-limited, you'll get an error in the completion handler
• Reuse MKLocalSearchCompleter instances — don't create new ones per query

---

Part 7: MKDirections and MKRoute

Calculate Directions

let request = MKDirections.Request()
request.source = MKMapItem.forCurrentLocation()
request.destination = destinationMapItem
request.transportType = .automobile
request.requestsAlternateRoutes = true   // Get multiple routes

let directions = MKDirections(request: request)
let response = try await directions.calculate()

for route in response.routes {
    route.polyline                  // MKPolyline — display on map
    route.expectedTravelTime       // TimeInterval in seconds
    route.distance                 // CLLocationDistance in meters
    route.name                     // "I-280 S" — route name
    route.advisoryNotices          // [String] — warnings
    route.steps                    // [MKRoute.Step] — turn-by-turn
}

Transport Types

.automobile    // Driving directions
.walking       // Pedestrian directions
.transit       // Public transit (where available)
.any           // All modes

ETA Only (Faster)

let directions = MKDirections(request: request)
let eta = try await directions.calculateETA()
eta.expectedTravelTime     // TimeInterval
eta.distance               // CLLocationDistance
eta.expectedArrivalDate    // Date
eta.expectedDepartureDate  // Date
eta.transportType          // MKDirectionsTransportType

Turn-by-Turn Steps

for step in route.steps {
    step.instructions    // "Turn right onto Main St"
    step.distance        // CLLocationDistance in meters
    step.polyline        // MKPolyline for this step's segment
    step.transportType   // May change for transit routes
    step.notice          // Optional advisory
}

---

Part 8: Look Around

Check Availability

let request = MKLookAroundSceneRequest(coordinate: coordinate)
do {
    let scene = try await request.scene
    // scene is non-nil — Look Around available at this coordinate
} catch {
    // Look Around not available here
}

SwiftUI

@State private var lookAroundScene: MKLookAroundScene?

LookAroundPreview(scene: $lookAroundScene)
    .frame(height: 200)

// Load scene
func loadLookAround(for coordinate: CLLocationCoordinate2D) async {
    let request = MKLookAroundSceneRequest(coordinate: coordinate)
    lookAroundScene = try? await request.scene
}

UIKit

let controller = MKLookAroundViewController(scene: scene)
// Present modally or embed as child view controller

Static Snapshot

let snapshotter = MKLookAroundSnapshotter(scene: scene, options: .init())
let snapshot = try await snapshotter.snapshot
let image = snapshot.image  // UIImage

---

Part 9: Overlays and Renderers

Adding Overlays (MKMapView)

// Circle
let circle = MKCircle(center: coordinate, radius: 1000)
mapView.addOverlay(circle)

// Polygon
let polygon = MKPolygon(coordinates: &coords, count: coords.count)
mapView.addOverlay(polygon)

// Polyline
let polyline = MKPolyline(coordinates: &coords, count: coords.count)
mapView.addOverlay(polyline, level: .aboveRoads)

// Custom tile overlay
let template = "https://tile.example.com/{z}/{x}/{y}.png"
let tileOverlay = MKTileOverlay(urlTemplate: template)
tileOverlay.canReplaceMapContent = true  // Hides Apple Maps base layer
mapView.addOverlay(tileOverlay, level: .aboveLabels)

Renderer Delegate

func mapView(_ mapView: MKMapView, rendererFor overlay: MKOverlay) -> MKOverlayRenderer {
    switch overlay {
    case let circle as MKCircle:
        let renderer = MKCircleRenderer(circle: circle)
        renderer.fillColor = UIColor.systemBlue.withAlphaComponent(0.2)
        renderer.strokeColor = .systemBlue
        renderer.lineWidth = 2
        return renderer

    case let polyline as MKPolyline:
        let renderer = MKPolylineRenderer(polyline: polyline)
        renderer.strokeColor = .systemBlue
        renderer.lineWidth = 4
        return renderer

    case let polygon as MKPolygon:
        let renderer = MKPolygonRenderer(polygon: polygon)
        renderer.fillColor = UIColor.systemGreen.withAlphaComponent(0.3)
        renderer.strokeColor = .systemGreen
        renderer.lineWidth = 2
        return renderer

      tile  :
         (tileOverlay: tile)

    :
         (overlay: overlay)
    }
}

Overlay Levels

mapView.addOverlay(overlay, level: .aboveRoads)    // Above roads, below labels
mapView.addOverlay(overlay, level: .aboveLabels)   // Above everything

Gradient Polyline

let renderer = MKGradientPolylineRenderer(polyline: polyline)
renderer.setColors([.green, .yellow, .red], locations: [0.0, 0.5, 1.0])
renderer.lineWidth = 6

---

Part 10: Map Snapshots

Generate static map images for sharing, thumbnails, or offline display:

let options = MKMapSnapshotter.Options()
options.region = MKCoordinateRegion(
    center: coordinate,
    span: MKCoordinateSpan(latitudeDelta: 0.01, longitudeDelta: 0.01)
)
options.size = CGSize(width: 300, height: 200)
options.scale = UIScreen.main.scale           // Retina support
options.mapType = .standard
options.showsBuildings = true
options.pointOfInterestFilter = .excludingAll  // Clean map

let snapshotter = MKMapSnapshotter(options: options)
let snapshot = try await snapshotter.start()
let image = snapshot.image

// Draw custom annotations on snapshot
UIGraphicsBeginImageContextWithOptions(image.size, true, image.scale)
image.draw(at: .zero)

let pinImage = UIImage(systemName: "mappin.circle.fill")!
let point = snapshot.point(for: coordinate)
pinImage.draw(at: CGPoint(
    x: point.x - pinImage.size.width / 2,
    y: point.y - pinImage.size.height
))

let finalImage = UIGraphicsGetImageFromCurrentImageContext()
()

Snapshot Coordinate Conversion

// Convert coordinate to point in snapshot image
let point = snapshot.point(for: coordinate)

// Check if coordinate is in snapshot bounds
let isVisible = CGRect(origin: .zero, size: snapshot.image.size).contains(point)

---

Part 11: iOS Version Feature Matrix

Feature	iOS Version
MKMapView	3.0+
MKLocalSearch	6.1+
MKDirections	7.0+
MKMarkerAnnotationView	11.0+
MKMapSnapshotter	7.0+
MKLookAroundSceneRequest	16.0+
LookAroundPreview (SwiftUI)	17.0+
SwiftUI Map (content builder)	17.0+
MapCameraPosition	17.0+
.mapSelection	17.0+
.mapCameraKeyframeAnimator	17.0+
.onMapCameraChange	17.0+
MapUserLocationButton	17.0+
MapCompass	17.0+
MapScaleView	17.0+
.mapInteractionModes	17.0+
MKLocalSearch.ResultType.query	18.0+
GeoToolbox / PlaceDescriptor	26.0+
MKGeocodingRequest	26.0+
MKReverseGeocodingRequest	26.0+
MKAddress	26.0+

---

Part 12: GeoToolbox and Geocoding

GeoToolbox Framework

GeoToolbox provides PlaceDescriptor — a standardized representation of physical locations that works across MapKit and third-party mapping services.

import GeoToolbox

// From address
let fountain = PlaceDescriptor(
    representations: [.address("121-122 James's St \n Dublin 8 \n D08 ET27 \n Ireland")],
    commonName: "Obelisk Fountain"
)

// From coordinates
let tower = PlaceDescriptor(
    representations: [.coordinate(CLLocationCoordinate2D(latitude: 48.8584, longitude: 2.2945))],
    commonName: "Eiffel Tower"
)

// Multiple representations
let statue = PlaceDescriptor(
    representations: [
        .coordinate(CLLocationCoordinate2D(latitude: 40.6892, longitude: -74.0445)),
        .address("Liberty Island, New York, NY 10004, United States")
    ],
    commonName: "Statue of Liberty"
)

// From MKMapItem
let descriptor = PlaceDescriptor(item: mapItem)  // Returns optional

PlaceRepresentation

Enum representing a place using common mapping concepts:

Case	Usage
.coordinate(CLLocationCoordinate2D)	Latitude/longitude
.address(String)	Full address string

Convenience accessors on PlaceDescriptor:

descriptor.coordinate  // CLLocationCoordinate2D?
descriptor.address     // String?
descriptor.commonName  // String?

SupportingPlaceRepresentation

Proprietary identifiers for places from different mapping services:

let place = PlaceDescriptor(
    representations: [.coordinate(CLLocationCoordinate2D(latitude: 51.5074, longitude: -0.1278))],
    commonName: "London Eye",
    supportingRepresentations: [
        .serviceIdentifiers([
            "com.apple.maps": "AppleMapsID123",
            "com.google.maps": "GoogleMapsID456"
        ])
    ]
)

// Retrieve a specific service identifier
let appleID = place.serviceIdentifier(for: "com.apple.maps")

MKGeocodingRequest — Forward Geocoding

Convert an address string to map items (address to coordinates):

guard let request = MKGeocodingRequest(addressString: "1 Apple Park Way, Cupertino, CA") else {
    return
}
let mapItems = try await request.mapItems

MKReverseGeocodingRequest — Reverse Geocoding

Convert coordinates to map items (coordinates to address):

let location = CLLocation(latitude: 37.3349, longitude: -122.0090)
guard let request = MKReverseGeocodingRequest(location: location) else {
    return
}
let mapItems = try await request.mapItems

MKAddress

Structured address type used when creating MKMapItem from a PlaceDescriptor:

if let coordinate = descriptor.coordinate {
    let location = CLLocation(latitude: coordinate.latitude, longitude: coordinate.longitude)
    let address = MKAddress()
    let mapItem = MKMapItem(location: location, address: address)
}

Geocoding vs MKLocalSearch

Need	Use
Address string to coordinates	MKGeocodingRequest
Coordinates to address	MKReverseGeocodingRequest
Natural language place search	MKLocalSearch
Autocomplete suggestions	MKLocalSearchCompleter
Cross-service place identifiers	PlaceDescriptor with SupportingPlaceRepresentation

---

Resources

WWDC: 2023-10043, 2024-10094

Docs: /mapkit, /mapkit/map, /mapkit/mklocalsearch, /mapkit/mkdirections, /geotoolbox, /geotoolbox/placedescriptor, /mapkit/mkgeocodingrequest, /mapkit/mkreversegeocodingrequest, /mapkit/mkaddress

Skills: mapkit, mapkit-diag, core-location-ref