Swift-ios-skills energykit
Query grid electricity forecasts and submit load events using EnergyKit to help users optimize home electricity usage. Use when building smart home apps, EV charger controls, HVAC scheduling, or energy management dashboards that guide users to use power during cleaner or cheaper grid periods.
git clone https://github.com/dpearson2699/swift-ios-skills
T=$(mktemp -d) && git clone --depth=1 https://github.com/dpearson2699/swift-ios-skills "$T" && mkdir -p ~/.claude/skills && cp -r "$T/skills/energykit" ~/.claude/skills/dpearson2699-swift-ios-skills-energykit && rm -rf "$T"
skills/energykit/SKILL.mdEnergyKit
Provide grid electricity forecasts to help users choose when to use electricity. EnergyKit identifies times when there is relatively cleaner or less expensive electricity on the grid, enabling apps to shift or reduce load accordingly. Targets Swift 6.3 / iOS 26+.
Beta-sensitive. EnergyKit is new in iOS 26 and may change before GM. Re-check current Apple documentation before relying on specific API details.
Contents
- Setup
- Core Concepts
- Querying Electricity Guidance
- Working with Guidance Values
- Energy Venues
- Submitting Load Events
- Electricity Insights
- Common Mistakes
- Review Checklist
- References
Setup
Entitlement
EnergyKit requires the
com.apple.developer.energykit entitlement. Add it
to your app's entitlements file.
Import
import EnergyKit
Platform availability: iOS 26+, iPadOS 26+.
Core Concepts
EnergyKit provides two main capabilities:
- Electricity Guidance -- time-weighted forecasts telling apps when electricity is cleaner or cheaper, so devices can shift or reduce consumption
- Load Events -- telemetry from devices (EV chargers, HVAC) submitted back to the system to track how well the app follows guidance
Key Types
| Type | Role |
|---|---|
| Forecast data with weighted time intervals |
| Interface for obtaining guidance data |
| Query specifying shift or reduce action |
| A time interval with a rating (0.0-1.0) |
| A physical location (home) registered for energy management |
| Load event for EV charger telemetry |
| Load event for HVAC system telemetry |
| Service for querying energy/runtime insights |
| Historical energy data broken down by cleanliness/tariff |
| Query for historical insight data |
Suggested Actions
| Action | Use Case |
|---|---|
| Devices that can move consumption to a different time (EV charging) |
| Devices that can lower consumption without stopping (HVAC setback) |
Querying Electricity Guidance
Use
ElectricityGuidance.Service to get a forecast stream for a venue.
import EnergyKit func observeGuidance(venueID: UUID) async throws { let query = ElectricityGuidance.Query(suggestedAction: .shift) let service = ElectricityGuidance.sharedService let guidanceStream = service.guidance(using: query, at: venueID) for try await guidance in guidanceStream { print("Guidance token: \(guidance.guidanceToken)") print("Interval: \(guidance.interval)") print("Venue: \(guidance.energyVenueID)") // Check if rate plan information is available if guidance.options.contains(.guidanceIncorporatesRatePlan) { print("Rate plan data incorporated") } if guidance.options.contains(.locationHasRatePlan) { print("Location has a rate plan") } processGuidanceValues(guidance.values) } }
Working with Guidance Values
Each
ElectricityGuidance.Value contains a time interval and a rating
from 0.0 to 1.0. Lower ratings indicate better times to use electricity.
func processGuidanceValues(_ values: [ElectricityGuidance.Value]) { for value in values { let interval = value.interval let rating = value.rating // 0.0 (best) to 1.0 (worst) print("From \(interval.start) to \(interval.end): rating \(rating)") } } // Find the best time to charge func bestChargingWindow( in values: [ElectricityGuidance.Value] ) -> ElectricityGuidance.Value? { values.min(by: { $0.rating < $1.rating }) } // Find all "good" windows below a threshold func goodWindows( in values: [ElectricityGuidance.Value], threshold: Double = 0.3 ) -> [ElectricityGuidance.Value] { values.filter { $0.rating <= threshold } }
Displaying Guidance in SwiftUI
import SwiftUI import EnergyKit struct GuidanceTimelineView: View { let values: [ElectricityGuidance.Value] var body: some View { List(values, id: \.interval.start) { value in HStack { VStack(alignment: .leading) { Text(value.interval.start, style: .time) Text(value.interval.end, style: .time) .foregroundStyle(.secondary) } Spacer() RatingIndicator(rating: value.rating) } } } } struct RatingIndicator: View { let rating: Double var color: Color { if rating <= 0.3 { return .green } if rating <= 0.6 { return .yellow } return .red } var label: String { if rating <= 0.3 { return "Good" } if rating <= 0.6 { return "Fair" } return "Avoid" } var body: some View { Text(label) .padding(.horizontal, 8) .padding(.vertical, 4) .background(color.opacity(0.2)) .foregroundStyle(color) .clipShape(Capsule()) } }
Energy Venues
An
EnergyVenue represents a physical location registered for energy management.
// List all venues func listVenues() async throws -> [EnergyVenue] { try await EnergyVenue.venues() } // Get a specific venue by ID func getVenue(id: UUID) async throws -> EnergyVenue { try await EnergyVenue.venue(for: id) } // Get a venue matching a HomeKit home func getVenueForHome(homeID: UUID) async throws -> EnergyVenue { try await EnergyVenue.venue(matchingHomeUniqueIdentifier: homeID) }
Venue Properties
let venue = try await EnergyVenue.venue(for: venueID) print("Venue ID: \(venue.id)") print("Venue name: \(venue.name)")
Submitting Load Events
Report device consumption data back to the system. This helps the system improve future guidance accuracy.
EV Charger Load Events
func submitEVChargingEvent( at venue: EnergyVenue, guidanceToken: UUID, deviceID: String ) async throws { let session = ElectricVehicleLoadEvent.Session( id: UUID(), state: .begin, guidanceState: ElectricVehicleLoadEvent.Session.GuidanceState( wasFollowingGuidance: true, guidanceToken: guidanceToken ) ) let measurement = ElectricVehicleLoadEvent.ElectricalMeasurement( stateOfCharge: 45, direction: .imported, power: Measurement(value: 7.2, unit: .kilowatts), energy: Measurement(value: 0, unit: .kilowattHours) ) let event = ElectricVehicleLoadEvent( timestamp: Date(), measurement: measurement, session: session, deviceID: deviceID ) try await venue.submitEvents([event]) }
HVAC Load Events
func submitHVACEvent( at venue: EnergyVenue, guidanceToken: UUID, stage: Int, deviceID: String ) async throws { let session = ElectricHVACLoadEvent.Session( id: UUID(), state: .active, guidanceState: ElectricHVACLoadEvent.Session.GuidanceState( wasFollowingGuidance: true, guidanceToken: guidanceToken ) ) let measurement = ElectricHVACLoadEvent.ElectricalMeasurement(stage: stage) let event = ElectricHVACLoadEvent( timestamp: Date(), measurement: measurement, session: session, deviceID: deviceID ) try await venue.submitEvents([event]) }
Session States
| State | When to Use |
|---|---|
| Device starts consuming electricity |
| Device is actively consuming (periodic updates) |
| Device stops consuming electricity |
Electricity Insights
Query historical energy and runtime data for devices using
ElectricityInsightService.
func queryEnergyInsights(deviceID: String, venueID: UUID) async throws { let query = ElectricityInsightQuery( options: [.cleanliness, .tariff], range: DateInterval( start: Calendar.current.date(byAdding: .day, value: -7, to: Date())!, end: Date() ), granularity: .daily, flowDirection: .imported ) let service = ElectricityInsightService.shared let stream = try await service.energyInsights( forDeviceID: deviceID, using: query, atVenue: venueID ) for await record in stream { if let total = record.totalEnergy { print("Total: \(total)") } if let cleaner = record.dataByGridCleanliness?.cleaner { print("Cleaner: \(cleaner)") } } }
Use
runtimeInsights(forDeviceID:using:atVenue:) for runtime data instead
of energy. Granularity options: .hourly, .daily, .weekly, .monthly,
.yearly. See references/energykit-patterns.md for full insight examples.
Common Mistakes
DON'T: Forget the EnergyKit entitlement
Without the entitlement, all EnergyKit calls fail silently or throw errors.
// WRONG: No entitlement configured let service = ElectricityGuidance.sharedService // Will fail // CORRECT: Add com.apple.developer.energykit to entitlements // Then use the service let service = ElectricityGuidance.sharedService
DON'T: Ignore unsupported regions
EnergyKit is not available in all regions. Handle the
.unsupportedRegion
and .guidanceUnavailable errors.
// WRONG: Assume guidance is always available for try await guidance in service.guidance(using: query, at: venueID) { updateUI(guidance) } // CORRECT: Handle region-specific errors do { for try await guidance in service.guidance(using: query, at: venueID) { updateUI(guidance) } } catch let error as EnergyKitError { switch error { case .unsupportedRegion: showUnsupportedRegionMessage() case .guidanceUnavailable: showGuidanceUnavailableMessage() case .venueUnavailable: showNoVenueMessage() case .permissionDenied: showPermissionDeniedMessage() case .serviceUnavailable: retryLater() case .rateLimitExceeded: backOff() default: break } }
DON'T: Discard the guidance token
The
guidanceToken links load events to the guidance that influenced them.
Always store and pass it through to load event submissions.
// WRONG: Ignore the guidance token for try await guidance in guidanceStream { startCharging() } // CORRECT: Store the token for load events for try await guidance in guidanceStream { let token = guidance.guidanceToken startCharging(followingGuidanceToken: token) }
DON'T: Submit load events without a session lifecycle
Always submit
.begin, then .active updates, then .end events.
// WRONG: Only submit one event let event = ElectricVehicleLoadEvent(/* state: .active */) try await venue.submitEvents([event]) // CORRECT: Full session lifecycle try await venue.submitEvents([beginEvent]) // ... periodic active events ... try await venue.submitEvents([activeEvent]) // ... when done ... try await venue.submitEvents([endEvent])
DON'T: Query guidance without a venue
EnergyKit requires a venue ID. List venues first and select the appropriate one.
// WRONG: Use a hardcoded UUID let fakeID = UUID() service.guidance(using: query, at: fakeID) // Will fail // CORRECT: Discover venues first let venues = try await EnergyVenue.venues() guard let venue = venues.first else { showNoVenueSetup() return } let guidanceStream = service.guidance(using: query, at: venue.id)
Review Checklist
-
entitlement added to the projectcom.apple.developer.energykit -
handled with user-facing messageEnergyKitError.unsupportedRegion -
handled gracefullyEnergyKitError.permissionDenied - Guidance token stored and passed to load event submissions
- Venues discovered via
before querying guidanceEnergyVenue.venues() - Load event sessions follow
->.begin
->.active
lifecycle.end -
interpreted correctly (lower is better)ElectricityGuidance.Value.rating -
matches the device type (SuggestedAction
for EV,.shift
for HVAC).reduce - Insight queries use appropriate granularity for the time range
- Rate limiting handled via
EnergyKitError.rateLimitExceeded - Service unavailability handled with retry logic
References
- Extended patterns (full app architecture, SwiftUI dashboard): references/energykit-patterns.md
- EnergyKit framework
- ElectricityGuidance
- ElectricityGuidance.Service
- ElectricityGuidance.Query
- ElectricityGuidance.Value
- EnergyVenue
- ElectricVehicleLoadEvent
- ElectricHVACLoadEvent
- ElectricityInsightService
- ElectricityInsightRecord
- ElectricityInsightQuery
- EnergyKitError
- Optimizing home electricity usage