diff --git a/iosApp/iosApp/Environment/DataManagerEnvironment.swift b/iosApp/iosApp/Environment/DataManagerEnvironment.swift
new file mode 100644
index 0000000..2590309
--- /dev/null
+++ b/iosApp/iosApp/Environment/DataManagerEnvironment.swift
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+import SwiftUI
+import ComposeApp
+
+/// SwiftUI `@Environment` mirror of Compose's `LocalDataManager` ambient.
+///
+/// Production views resolve `@Environment(\.dataManager)` to
+/// `DataManagerObservable.shared` — the existing Swift-side mirror of the
+/// shared Kotlin `DataManager` singleton. Tests, previews, and the
+/// parity-gallery override via:
+///
+/// ```swift
+/// MyView()
+///     .environment(\.dataManager, FakeDataManagerObservable())
+/// ```
+///
+/// This key is intentionally introduced without migrating any SwiftUI
+/// screens yet. Views continue to access `DataManagerObservable.shared`
+/// directly; the actual view-level migration lands when parity-gallery
+/// fixtures arrive (P1), at which point ViewModels will gain an optional
+/// init param that accepts a `DataManagerObservable` resolved from this
+/// environment key.
+struct DataManagerEnvironmentKey: EnvironmentKey {
+    static let defaultValue: DataManagerObservable = DataManagerObservable.shared
+}
+
+extension EnvironmentValues {
+    var dataManager: DataManagerObservable {
+        get { self[DataManagerEnvironmentKey.self] }
+        set { self[DataManagerEnvironmentKey.self] = newValue }
+    }
+}