diff --git a/Package.swift b/Package.swift
index 79aba66..a872f4f 100644
--- a/Package.swift
+++ b/Package.swift
@@ -1,4 +1,4 @@
-// swift-tools-version: 5.9
+// swift-tools-version: 6.1
 // This is a Skip (https://skip.dev) package,
 // containing a Swift Package Manager project
 // that will use the Skip build plugin to transpile the
diff --git a/Sources/SkipKit/Cache.swift b/Sources/SkipKit/Cache.swift
index 6fda47b..f86baba 100644
--- a/Sources/SkipKit/Cache.swift
+++ b/Sources/SkipKit/Cache.swift
@@ -10,7 +10,7 @@ public class Cache<Key: Hashable, Value> {
     private let cacheLock = NSLock()
     private let manager: CacheManager<Key, Value>
 
-    public init(evictOnBackground: Bool = true, limit: Int? = nil, cost: ((Value) -> Int)? = nil) {
+    public init(evictOnBackground: Bool = true, limit: Int? = nil, cost: (@Sendable (Value) -> Int)? = nil) {
         self.manager = CacheManager(evictOnBackground: evictOnBackground, limit: limit, cost: cost)
     }
 
@@ -154,10 +154,10 @@ private final class LRUCostCache<Key, Value>: android.util.LruCache<Key, Value>
 }
 
 #else
-private final class CacheManager<Key: Hashable, Value>: NSObject, NSCacheDelegate {
+private final class CacheManager<Key: Hashable, Value>: NSObject, NSCacheDelegate, @unchecked Sendable {
     let cache = NSCache<CacheKey, CacheValue>()
     let limit: Int?
-    let cost: ((Value) -> Int)?
+    let cost: (@Sendable (Value) -> Int)?
     private var didEnterBackgroundObserver: NSObjectProtocol?
     #if canImport(UIKit)
     /// https://developer.apple.com/documentation/uikit/uiapplication/didenterbackgroundnotification
@@ -167,7 +167,7 @@ private final class CacheManager<Key: Hashable, Value>: NSObject, NSCacheDelegat
     private let backgroundNotificationName = Notification.Name("NSApplicationDidResignActiveNotification")
     #endif
 
-    public init(evictOnBackground: Bool, limit: Int?, cost: ((Value) -> Int)?) {
+    public init(evictOnBackground: Bool, limit: Int?, cost: (@Sendable (Value) -> Int)?) {
         self.limit = limit
         self.cost = cost
 
diff --git a/Sources/SkipKit/DeviceInfo.swift b/Sources/SkipKit/DeviceInfo.swift
index be22020..9f3e95e 100644
--- a/Sources/SkipKit/DeviceInfo.swift
+++ b/Sources/SkipKit/DeviceInfo.swift
@@ -90,7 +90,7 @@ public final class DeviceInfo {
         let dm = context.getResources().getDisplayMetrics()
         return Double(dm.widthPixels) / Double(dm.density)
         #elseif canImport(UIKit)
-        return Double(UIScreen.main.bounds.width)
+        return MainActor.assumeIsolated { Double(UIScreen.main.bounds.width) }
         #elseif os(macOS)
         return Double(NSScreen.main?.frame.width ?? 0)
         #else
@@ -105,7 +105,7 @@ public final class DeviceInfo {
         let dm = context.getResources().getDisplayMetrics()
         return Double(dm.heightPixels) / Double(dm.density)
         #elseif canImport(UIKit)
-        return Double(UIScreen.main.bounds.height)
+        return MainActor.assumeIsolated { Double(UIScreen.main.bounds.height) }
         #elseif os(macOS)
         return Double(NSScreen.main?.frame.height ?? 0)
         #else
@@ -119,7 +119,7 @@ public final class DeviceInfo {
         let context = ProcessInfo.processInfo.androidContext
         return Double(context.getResources().getDisplayMetrics().density)
         #elseif canImport(UIKit)
-        return Double(UIScreen.main.scale)
+        return MainActor.assumeIsolated { Double(UIScreen.main.scale) }
         #elseif os(macOS)
         return Double(NSScreen.main?.backingScaleFactor ?? 1.0)
         #else
@@ -146,12 +146,14 @@ public final class DeviceInfo {
             return .phone
         }
         #elseif canImport(UIKit)
-        switch UIDevice.current.userInterfaceIdiom {
-        case .phone: return .phone
-        case .pad: return .tablet
-        case .tv: return .tv
-        case .mac: return .desktop
-        default: return .unknown
+        return MainActor.assumeIsolated {
+            switch UIDevice.current.userInterfaceIdiom {
+            case .phone: return .phone
+            case .pad: return .tablet
+            case .tv: return .tv
+            case .mac: return .desktop
+            default: return .unknown
+            }
         }
         #elseif os(macOS)
         return .desktop
@@ -231,13 +233,15 @@ public final class DeviceInfo {
         if level < 0 { return nil }
         return Double(level) / 100.0
         #elseif canImport(UIKit)
-        let device = UIDevice.current
-        let wasEnabled = device.isBatteryMonitoringEnabled
-        device.isBatteryMonitoringEnabled = true
-        let level = device.batteryLevel
-        if !wasEnabled { device.isBatteryMonitoringEnabled = false }
-        if level < 0 { return nil }
-        return Double(level)
+        return MainActor.assumeIsolated {
+            let device = UIDevice.current
+            let wasEnabled = device.isBatteryMonitoringEnabled
+            device.isBatteryMonitoringEnabled = true
+            let level = device.batteryLevel
+            if !wasEnabled { device.isBatteryMonitoringEnabled = false }
+            if level < 0 { return nil }
+            return Double(level)
+        }
         #else
         return nil
         #endif
@@ -258,17 +262,19 @@ public final class DeviceInfo {
         }
         return .unplugged
         #elseif canImport(UIKit)
-        let device = UIDevice.current
-        let wasEnabled = device.isBatteryMonitoringEnabled
-        device.isBatteryMonitoringEnabled = true
-        let state = device.batteryState
-        if !wasEnabled { device.isBatteryMonitoringEnabled = false }
-        switch state {
-        case .unplugged: return .unplugged
-        case .charging: return .charging
-        case .full: return .full
-        case .unknown: return .unknown
-        @unknown default: return .unknown
+        return MainActor.assumeIsolated {
+            let device = UIDevice.current
+            let wasEnabled = device.isBatteryMonitoringEnabled
+            device.isBatteryMonitoringEnabled = true
+            let state = device.batteryState
+            if !wasEnabled { device.isBatteryMonitoringEnabled = false }
+            switch state {
+            case .unplugged: return .unplugged
+            case .charging: return .charging
+            case .full: return .full
+            case .unknown: return .unknown
+            @unknown default: return .unknown
+            }
         }
         #else
         return .unknown
@@ -289,16 +295,17 @@ public final class DeviceInfo {
         #elseif canImport(Network)
         let monitor = NWPathMonitor()
         let queue = DispatchQueue(label: "skip.kit.network.snapshot")
-        var result: NetworkStatus = .offline
+        final class Box: @unchecked Sendable { var value: NetworkStatus = .offline }
+        let result = Box()
         let semaphore = DispatchSemaphore(value: 0)
         monitor.pathUpdateHandler = { path in
-            result = Self.mapNWPath(path)
+            result.value = Self.mapNWPath(path)
             semaphore.signal()
         }
         monitor.start(queue: queue)
         _ = semaphore.wait(timeout: .now() + 1.0)
         monitor.cancel()
-        return result
+        return result.value
         #else
         return .offline
         #endif
diff --git a/Sources/SkipKit/HapticFeedback.swift b/Sources/SkipKit/HapticFeedback.swift
index 60c53cc..4490fa6 100644
--- a/Sources/SkipKit/HapticFeedback.swift
+++ b/Sources/SkipKit/HapticFeedback.swift
@@ -7,7 +7,7 @@ import CoreHaptics
 #endif
 
 /// A single haptic event within a pattern.
-public struct HapticEvent {
+public struct HapticEvent: Sendable {
     /// The type of haptic primitive to play.
     public let type: HapticEventType
     /// Intensity from 0.0 to 1.0.
@@ -23,7 +23,7 @@ public struct HapticEvent {
 }
 
 /// The type of haptic primitive.
-public enum HapticEventType {
+public enum HapticEventType: Sendable {
     /// A short, sharp tap. The most common haptic element.
     case tap
     /// A subtle, light tick. Good for selections and fine adjustments.
@@ -39,7 +39,7 @@ public enum HapticEventType {
 }
 
 /// A sequence of haptic events that form a complete feedback pattern.
-public struct HapticPattern {
+public struct HapticPattern: Sendable {
     public let events: [HapticEvent]
 
     public init(_ events: [HapticEvent]) {
@@ -135,7 +135,7 @@ extension HapticPattern {
 /// Plays custom haptic patterns on both iOS and Android.
 public final class HapticFeedback {
     #if canImport(CoreHaptics)
-    private static var engine: CHHapticEngine?
+    nonisolated(unsafe) private static var engine: CHHapticEngine?
     #endif
 
     /// Play a haptic pattern. Call from any thread.
diff --git a/Sources/SkipKit/MailComposer.swift b/Sources/SkipKit/MailComposer.swift
index 1f587c9..3663340 100644
--- a/Sources/SkipKit/MailComposer.swift
+++ b/Sources/SkipKit/MailComposer.swift
@@ -105,7 +105,7 @@ public enum MailComposer {
         intent.setData(Uri.parse("mailto:"))
         return intent.resolveActivity(context.getPackageManager()) != nil
         #elseif os(iOS)
-        return MFMailComposeViewController.canSendMail()
+        return MainActor.assumeIsolated { MFMailComposeViewController.canSendMail() }
         #else
         return false
         #endif
diff --git a/Sources/SkipKit/PermissionManager.swift b/Sources/SkipKit/PermissionManager.swift
index 7fd9a30..349e684 100644
--- a/Sources/SkipKit/PermissionManager.swift
+++ b/Sources/SkipKit/PermissionManager.swift
@@ -5,8 +5,6 @@ import Foundation
 import SwiftUI
 #if !SKIP
 import Photos
-// import Contacts // TODO: create framework skip-contacts
-// import EventKit // TODO: create framework skip-calendar
 import AVFoundation
 import CoreLocation
 import UserNotifications
@@ -453,7 +451,7 @@ public class PermissionManager {
 /// A delegate that encapsulates a `CLLocationManager` and handles `locationManagerDidChangeAuthorization`
 class LocationDelegate: NSObject, CLLocationManagerDelegate {
     /// For some reason, we need to keep just a single reference to CLLocationManager around for the locationManagerDidChangeAuthorization to get called reliably
-    static let shared = LocationDelegate()
+    nonisolated(unsafe) static let shared = LocationDelegate()
 
     lazy var locationManager = CLLocationManager()
     var continuation: CheckedContinuation<Void, Never>?
@@ -510,7 +508,7 @@ public enum PermissionAuthorization : String {
 }
 
 /// The encapsulation of a permission name
-public struct PermissionType : Equatable {
+public struct PermissionType : Equatable, Sendable {
     public let androidPermissionName: String
 
     public init(androidPermissionName: String) {
diff --git a/Sources/SkipKit/WebBrowser.swift b/Sources/SkipKit/WebBrowser.swift
index 1569e11..51542f9 100644
--- a/Sources/SkipKit/WebBrowser.swift
+++ b/Sources/SkipKit/WebBrowser.swift
@@ -204,7 +204,8 @@ private struct SafariViewWrapper: UIViewControllerRepresentable {
     }
 }
 
-private class SafariCoordinator: NSObject, SFSafariViewControllerDelegate {
+@MainActor
+private class SafariCoordinator: NSObject, @preconcurrency SFSafariViewControllerDelegate {
     let parent: SafariViewWrapper
 
     init(parent: SafariViewWrapper) {