feat(mobile): stack original + edited photo on ios

Detect an iOS edit, upload the unedited original, and stack the edited
version on top of it. Reverting in Photos flips back to a single original.
Adds an optional stackParentId field to the asset upload on the server.

mobile/android/app/src/main/kotlin/app/alextran/immich/sync/Messages.g.kt

@@ -207,6 +207,18 @@ enum class PlatformAssetPlaybackStyle(val raw: Int) {
   }
 }
 
+enum class EditState(val raw: Int) {
+  NOT_EDITED(0),
+  EDITED(1),
+  UNKNOWN(2);
+
+  companion object {
+    fun ofRaw(raw: Int): EditState? {
+      return values().firstOrNull { it.raw == raw }
+    }
+  }
+}
+
 /** Generated class from Pigeon that represents data sent in messages. */
 data class PlatformAsset (
   val id: String,
@@ -472,6 +484,52 @@ data class CloudIdResult (
     return result
   }
 }
+
+/** Generated class from Pigeon that represents data sent in messages. */
+data class BaseResource (
+  val path: String,
+  val sha1: String,
+  val sizeBytes: Long,
+  val mimeType: String
+)
+ {
+  companion object {
+    fun fromList(pigeonVar_list: List<Any?>): BaseResource {
+      val path = pigeonVar_list[0] as String
+      val sha1 = pigeonVar_list[1] as String
+      val sizeBytes = pigeonVar_list[2] as Long
+      val mimeType = pigeonVar_list[3] as String
+      return BaseResource(path, sha1, sizeBytes, mimeType)
+    }
+  }
+  fun toList(): List<Any?> {
+    return listOf(
+      path,
+      sha1,
+      sizeBytes,
+      mimeType,
+    )
+  }
+  override fun equals(other: Any?): Boolean {
+    if (other == null || other.javaClass != javaClass) {
+      return false
+    }
+    if (this === other) {
+      return true
+    }
+    val other = other as BaseResource
+    return MessagesPigeonUtils.deepEquals(this.path, other.path) && MessagesPigeonUtils.deepEquals(this.sha1, other.sha1) && MessagesPigeonUtils.deepEquals(this.sizeBytes, other.sizeBytes) && MessagesPigeonUtils.deepEquals(this.mimeType, other.mimeType)
+  }
+
+  override fun hashCode(): Int {
+    var result = javaClass.hashCode()
+    result = 31 * result + MessagesPigeonUtils.deepHash(this.path)
+    result = 31 * result + MessagesPigeonUtils.deepHash(this.sha1)
+    result = 31 * result + MessagesPigeonUtils.deepHash(this.sizeBytes)
+    result = 31 * result + MessagesPigeonUtils.deepHash(this.mimeType)
+    return result
+  }
+}
 private open class MessagesPigeonCodec : StandardMessageCodec() {
   override fun readValueOfType(type: Byte, buffer: ByteBuffer): Any? {
     return when (type) {
@@ -481,30 +539,40 @@ private open class MessagesPigeonCodec : StandardMessageCodec() {
         }
       }
       130.toByte() -> {
-        return (readValue(buffer) as? List<Any?>)?.let {
-          PlatformAsset.fromList(it)
+        return (readValue(buffer) as Long?)?.let {
+          EditState.ofRaw(it.toInt())
         }
       }
       131.toByte() -> {
         return (readValue(buffer) as? List<Any?>)?.let {
-          PlatformAlbum.fromList(it)
+          PlatformAsset.fromList(it)
         }
       }
       132.toByte() -> {
         return (readValue(buffer) as? List<Any?>)?.let {
-          SyncDelta.fromList(it)
+          PlatformAlbum.fromList(it)
         }
       }
       133.toByte() -> {
         return (readValue(buffer) as? List<Any?>)?.let {
-          HashResult.fromList(it)
+          SyncDelta.fromList(it)
         }
       }
       134.toByte() -> {
+        return (readValue(buffer) as? List<Any?>)?.let {
+          HashResult.fromList(it)
+        }
+      }
+      135.toByte() -> {
         return (readValue(buffer) as? List<Any?>)?.let {
           CloudIdResult.fromList(it)
         }
       }
+      136.toByte() -> {
+        return (readValue(buffer) as? List<Any?>)?.let {
+          BaseResource.fromList(it)
+        }
+      }
       else -> super.readValueOfType(type, buffer)
     }
   }
@@ -514,26 +582,34 @@ private open class MessagesPigeonCodec : StandardMessageCodec() {
         stream.write(129)
         writeValue(stream, value.raw.toLong())
       }
-      is PlatformAsset -> {
+      is EditState -> {
         stream.write(130)
-        writeValue(stream, value.toList())
+        writeValue(stream, value.raw.toLong())
       }
-      is PlatformAlbum -> {
+      is PlatformAsset -> {
         stream.write(131)
         writeValue(stream, value.toList())
       }
-      is SyncDelta -> {
+      is PlatformAlbum -> {
         stream.write(132)
         writeValue(stream, value.toList())
       }
-      is HashResult -> {
+      is SyncDelta -> {
         stream.write(133)
         writeValue(stream, value.toList())
       }
-      is CloudIdResult -> {
+      is HashResult -> {
         stream.write(134)
         writeValue(stream, value.toList())
       }
+      is CloudIdResult -> {
+        stream.write(135)
+        writeValue(stream, value.toList())
+      }
+      is BaseResource -> {
+        stream.write(136)
+        writeValue(stream, value.toList())
+      }
       else -> super.writeValue(stream, value)
     }
   }
@@ -554,6 +630,8 @@ interface NativeSyncApi {
   fun cancelHashing()
   fun getTrashedAssets(): Map<String, List<PlatformAsset>>
   fun getCloudIdForAssetIds(assetIds: List<String>): List<CloudIdResult>
+  fun getBaseResource(assetId: String, allowNetworkAccess: Boolean, callback: (Result<BaseResource?>) -> Unit)
+  fun getEditState(assetId: String, allowNetworkAccess: Boolean, callback: (Result<EditState>) -> Unit)
 
   companion object {
     /** The codec used by NativeSyncApi. */
@@ -764,6 +842,48 @@ interface NativeSyncApi {
           channel.setMessageHandler(null)
         }
       }
+      run {
+        val channel = BasicMessageChannel<Any?>(binaryMessenger, "dev.flutter.pigeon.immich_mobile.NativeSyncApi.getBaseResource$separatedMessageChannelSuffix", codec, taskQueue)
+        if (api != null) {
+          channel.setMessageHandler { message, reply ->
+            val args = message as List<Any?>
+            val assetIdArg = args[0] as String
+            val allowNetworkAccessArg = args[1] as Boolean
+            api.getBaseResource(assetIdArg, allowNetworkAccessArg) { result: Result<BaseResource?> ->
+              val error = result.exceptionOrNull()
+              if (error != null) {
+                reply.reply(MessagesPigeonUtils.wrapError(error))
+              } else {
+                val data = result.getOrNull()
+                reply.reply(MessagesPigeonUtils.wrapResult(data))
+              }
+            }
+          }
+        } else {
+          channel.setMessageHandler(null)
+        }
+      }
+      run {
+        val channel = BasicMessageChannel<Any?>(binaryMessenger, "dev.flutter.pigeon.immich_mobile.NativeSyncApi.getEditState$separatedMessageChannelSuffix", codec, taskQueue)
+        if (api != null) {
+          channel.setMessageHandler { message, reply ->
+            val args = message as List<Any?>
+            val assetIdArg = args[0] as String
+            val allowNetworkAccessArg = args[1] as Boolean
+            api.getEditState(assetIdArg, allowNetworkAccessArg) { result: Result<EditState> ->
+              val error = result.exceptionOrNull()
+              if (error != null) {
+                reply.reply(MessagesPigeonUtils.wrapError(error))
+              } else {
+                val data = result.getOrNull()
+                reply.reply(MessagesPigeonUtils.wrapResult(data))
+              }
+            }
+          }
+        } else {
+          channel.setMessageHandler(null)
+        }
+      }
     }
   }
 }

mobile/android/app/src/main/kotlin/app/alextran/immich/sync/MessagesImplBase.kt

@@ -453,4 +453,14 @@ open class NativeSyncApiImplBase(context: Context) : ImmichPlugin() {
   fun getCloudIdForAssetIds(assetIds: List<String>): List<CloudIdResult> {
     return emptyList()
   }
+
+  // Android has no Photos-style edit original to stack; iOS-only.
+  fun getBaseResource(assetId: String, allowNetworkAccess: Boolean, callback: (Result<BaseResource?>) -> Unit) {
+    callback(Result.success(null))
+  }
+
+  // iOS-only; Android assets never carry a Photos-style edit.
+  fun getEditState(assetId: String, allowNetworkAccess: Boolean, callback: (Result<EditState>) -> Unit) {
+    callback(Result.success(EditState.NOT_EDITED))
+  }
 }

mobile/ios/Runner/Sync/Messages.g.swift

@@ -183,6 +183,12 @@ enum PlatformAssetPlaybackStyle: Int {
   case videoLooping = 5
 }
 
+enum EditState: Int {
+  case notEdited = 0
+  case edited = 1
+  case unknown = 2
+}
+
 /// Generated class from Pigeon that represents data sent in messages.
 struct PlatformAsset: Hashable {
   var id: String
@@ -458,6 +464,52 @@ struct CloudIdResult: Hashable {
   }
 }
 
+/// Generated class from Pigeon that represents data sent in messages.
+struct BaseResource: Hashable {
+  var path: String
+  var sha1: String
+  var sizeBytes: Int64
+  var mimeType: String
+
+
+  // swift-format-ignore: AlwaysUseLowerCamelCase
+  static func fromList(_ pigeonVar_list: [Any?]) -> BaseResource? {
+    let path = pigeonVar_list[0] as! String
+    let sha1 = pigeonVar_list[1] as! String
+    let sizeBytes = pigeonVar_list[2] as! Int64
+    let mimeType = pigeonVar_list[3] as! String
+
+    return BaseResource(
+      path: path,
+      sha1: sha1,
+      sizeBytes: sizeBytes,
+      mimeType: mimeType
+    )
+  }
+  func toList() -> [Any?] {
+    return [
+      path,
+      sha1,
+      sizeBytes,
+      mimeType,
+    ]
+  }
+  static func == (lhs: BaseResource, rhs: BaseResource) -> Bool {
+    if Swift.type(of: lhs) != Swift.type(of: rhs) {
+      return false
+    }
+    return deepEqualsMessages(lhs.path, rhs.path) && deepEqualsMessages(lhs.sha1, rhs.sha1) && deepEqualsMessages(lhs.sizeBytes, rhs.sizeBytes) && deepEqualsMessages(lhs.mimeType, rhs.mimeType)
+  }
+
+  func hash(into hasher: inout Hasher) {
+    hasher.combine("BaseResource")
+    deepHashMessages(value: path, hasher: &hasher)
+    deepHashMessages(value: sha1, hasher: &hasher)
+    deepHashMessages(value: sizeBytes, hasher: &hasher)
+    deepHashMessages(value: mimeType, hasher: &hasher)
+  }
+}
+
 private class MessagesPigeonCodecReader: FlutterStandardReader {
   override func readValue(ofType type: UInt8) -> Any? {
     switch type {
@@ -468,15 +520,23 @@ private class MessagesPigeonCodecReader: FlutterStandardReader {
       }
       return nil
     case 130:
-      return PlatformAsset.fromList(self.readValue() as! [Any?])
+      let enumResultAsInt: Int? = nilOrValue(self.readValue() as! Int?)
+      if let enumResultAsInt = enumResultAsInt {
+        return EditState(rawValue: enumResultAsInt)
+      }
+      return nil
     case 131:
-      return PlatformAlbum.fromList(self.readValue() as! [Any?])
+      return PlatformAsset.fromList(self.readValue() as! [Any?])
     case 132:
-      return SyncDelta.fromList(self.readValue() as! [Any?])
+      return PlatformAlbum.fromList(self.readValue() as! [Any?])
     case 133:
-      return HashResult.fromList(self.readValue() as! [Any?])
+      return SyncDelta.fromList(self.readValue() as! [Any?])
     case 134:
+      return HashResult.fromList(self.readValue() as! [Any?])
+    case 135:
       return CloudIdResult.fromList(self.readValue() as! [Any?])
+    case 136:
+      return BaseResource.fromList(self.readValue() as! [Any?])
     default:
       return super.readValue(ofType: type)
     }
@@ -488,21 +548,27 @@ private class MessagesPigeonCodecWriter: FlutterStandardWriter {
     if let value = value as? PlatformAssetPlaybackStyle {
       super.writeByte(129)
       super.writeValue(value.rawValue)
-    } else if let value = value as? PlatformAsset {
+    } else if let value = value as? EditState {
       super.writeByte(130)
-      super.writeValue(value.toList())
-    } else if let value = value as? PlatformAlbum {
+      super.writeValue(value.rawValue)
+    } else if let value = value as? PlatformAsset {
       super.writeByte(131)
       super.writeValue(value.toList())
-    } else if let value = value as? SyncDelta {
+    } else if let value = value as? PlatformAlbum {
       super.writeByte(132)
       super.writeValue(value.toList())
-    } else if let value = value as? HashResult {
+    } else if let value = value as? SyncDelta {
       super.writeByte(133)
       super.writeValue(value.toList())
-    } else if let value = value as? CloudIdResult {
+    } else if let value = value as? HashResult {
       super.writeByte(134)
       super.writeValue(value.toList())
+    } else if let value = value as? CloudIdResult {
+      super.writeByte(135)
+      super.writeValue(value.toList())
+    } else if let value = value as? BaseResource {
+      super.writeByte(136)
+      super.writeValue(value.toList())
     } else {
       super.writeValue(value)
     }
@@ -538,6 +604,8 @@ protocol NativeSyncApi {
   func cancelHashing() throws
   func getTrashedAssets() throws -> [String: [PlatformAsset]]
   func getCloudIdForAssetIds(assetIds: [String]) throws -> [CloudIdResult]
+  func getBaseResource(assetId: String, allowNetworkAccess: Bool, completion: @escaping (Result<BaseResource?, Error>) -> Void)
+  func getEditState(assetId: String, allowNetworkAccess: Bool, completion: @escaping (Result<EditState, Error>) -> Void)
 }
 
 /// Generated setup class from Pigeon to handle messages through the `binaryMessenger`.
@@ -738,5 +806,45 @@ class NativeSyncApiSetup {
     } else {
       getCloudIdForAssetIdsChannel.setMessageHandler(nil)
     }
+    let getBaseResourceChannel = taskQueue == nil
+      ? FlutterBasicMessageChannel(name: "dev.flutter.pigeon.immich_mobile.NativeSyncApi.getBaseResource\(channelSuffix)", binaryMessenger: binaryMessenger, codec: codec)
+      : FlutterBasicMessageChannel(name: "dev.flutter.pigeon.immich_mobile.NativeSyncApi.getBaseResource\(channelSuffix)", binaryMessenger: binaryMessenger, codec: codec, taskQueue: taskQueue)
+    if let api = api {
+      getBaseResourceChannel.setMessageHandler { message, reply in
+        let args = message as! [Any?]
+        let assetIdArg = args[0] as! String
+        let allowNetworkAccessArg = args[1] as! Bool
+        api.getBaseResource(assetId: assetIdArg, allowNetworkAccess: allowNetworkAccessArg) { result in
+          switch result {
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
+          }
+        }
+      }
+    } else {
+      getBaseResourceChannel.setMessageHandler(nil)
+    }
+    let getEditStateChannel = taskQueue == nil
+      ? FlutterBasicMessageChannel(name: "dev.flutter.pigeon.immich_mobile.NativeSyncApi.getEditState\(channelSuffix)", binaryMessenger: binaryMessenger, codec: codec)
+      : FlutterBasicMessageChannel(name: "dev.flutter.pigeon.immich_mobile.NativeSyncApi.getEditState\(channelSuffix)", binaryMessenger: binaryMessenger, codec: codec, taskQueue: taskQueue)
+    if let api = api {
+      getEditStateChannel.setMessageHandler { message, reply in
+        let args = message as! [Any?]
+        let assetIdArg = args[0] as! String
+        let allowNetworkAccessArg = args[1] as! Bool
+        api.getEditState(assetId: assetIdArg, allowNetworkAccess: allowNetworkAccessArg) { result in
+          switch result {
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
+          }
+        }
+      }
+    } else {
+      getEditStateChannel.setMessageHandler(nil)
+    }
   }
 }

mobile/ios/Runner/Sync/MessagesImpl.swift

@@ -1,5 +1,6 @@
 import Photos
 import CryptoKit
+import UniformTypeIdentifiers
 
 struct AssetWrapper: Hashable, Equatable {
   let asset: PlatformAsset
@@ -415,4 +416,135 @@ class NativeSyncApiImpl: ImmichPlugin, NativeSyncApi, FlutterPlugin {
     }
     return mappings;
   }
+
+  func getBaseResource(
+    assetId: String,
+    allowNetworkAccess: Bool,
+    completion: @escaping (Result<BaseResource?, Error>) -> Void
+  ) {
+    Task { [weak self] in
+      guard let self = self else { return }
+
+      guard let asset = PHAsset.fetchAssets(withLocalIdentifiers: [assetId], options: nil).firstObject else {
+        return self.completeWhenActive(for: completion, with: .success(nil))
+      }
+
+      let resources = PHAssetResource.assetResources(for: asset)
+      let state = await Self.classifyEdit(resources: resources, allowNetworkAccess: allowNetworkAccess)
+      guard state == .edited, let original = resources.first(where: { $0.type == .photo }) else {
+        return self.completeWhenActive(for: completion, with: .success(nil))
+      }
+
+      do {
+        let result = try await self.streamBaseResource(
+          resource: original,
+          localId: asset.localIdentifier,
+          allowNetworkAccess: allowNetworkAccess
+        )
+        self.completeWhenActive(for: completion, with: .success(result))
+      } catch {
+        self.completeWhenActive(for: completion, with: .failure(error))
+      }
+    }
+  }
+
+  // Returns whether the asset carries a live Photos edit without reading the photo
+  // itself, only the small adjustment metadata. The revert probe relies on this to
+  // tell "not edited" apart from "couldn't read" (offloaded to iCloud), so it never
+  // mistakes an unreadable edit for a revert.
+  func getEditState(
+    assetId: String,
+    allowNetworkAccess: Bool,
+    completion: @escaping (Result<EditState, Error>) -> Void
+  ) {
+    Task { [weak self] in
+      guard let self = self else { return }
+      guard let asset = PHAsset.fetchAssets(withLocalIdentifiers: [assetId], options: nil).firstObject else {
+        // Not in the library — don't let the caller act on a "not edited" answer.
+        return self.completeWhenActive(for: completion, with: .success(.unknown))
+      }
+      let state = await Self.classifyEdit(
+        resources: PHAssetResource.assetResources(for: asset),
+        allowNetworkAccess: allowNetworkAccess
+      )
+      self.completeWhenActive(for: completion, with: .success(state))
+    }
+  }
+
+  // adjustmentRenderTypes value of a photo with no live user edit — a plain
+  // capture (incl. Photographic Style) or a reverted edit. Any real edit moves it.
+  private static let kNoEditRenderTypes = 27648
+
+  // Classifies an asset's edit state from its Adjustments.plist, reading only the
+  // adjustment metadata (not the photo). A Photos edit is authored by
+  // com.apple.mobileslideshow (or a third-party editor) and moves the render
+  // pipeline off the no-edit baseline; a capture (including a Photographic Style)
+  // is authored by com.apple.camera, and a revert keeps the Photos editor id but
+  // restores the baseline render types — so requiring both excludes reverts.
+  // Cleanup/object-removal stays camera-attributed but writes
+  // AdjustmentsSecondary.data, the fallback. `.unknown` = the adjustment data
+  // couldn't be read (e.g. offloaded with network disallowed).
+  private static func classifyEdit(resources: [PHAssetResource], allowNetworkAccess: Bool) async -> EditState {
+    if resources.contains(where: { $0.originalFilename == "AdjustmentsSecondary.data" }) {
+      return .edited
+    }
+    guard let adjRes = resources.first(where: { $0.originalFilename == "Adjustments.plist" }) else {
+      return .notEdited
+    }
+    guard let buf = await collectResourceData(adjRes, allowNetworkAccess: allowNetworkAccess),
+      let plist = try? PropertyListSerialization.propertyList(from: buf, options: [], format: nil) as? [String: Any]
+    else {
+      return .unknown
+    }
+    let editor = plist["adjustmentEditorBundleID"] as? String
+    let renderTypes = (plist["adjustmentRenderTypes"] as? NSNumber)?.intValue
+    let isUserEdit = editor != nil && editor != "com.apple.camera" && renderTypes != kNoEditRenderTypes
+    return isUserEdit ? .edited : .notEdited
+  }
+
+  private func streamBaseResource(
+    resource: PHAssetResource,
+    localId: String,
+    allowNetworkAccess: Bool
+  ) async throws -> BaseResource {
+    guard let data = await Self.collectResourceData(resource, allowNetworkAccess: allowNetworkAccess) else {
+      throw NSError(
+        domain: "NativeSyncApi",
+        code: -1,
+        userInfo: [NSLocalizedDescriptionKey: "Failed to read base resource for \(localId)"]
+      )
+    }
+
+    let safeId = localId.replacingOccurrences(of: "/", with: "_")
+    let suffix = UTType(resource.uniformTypeIdentifier)?.preferredFilenameExtension ?? "bin"
+    let tempDir = URL(fileURLWithPath: NSTemporaryDirectory(), isDirectory: true)
+      .appendingPathComponent("immich_base", isDirectory: true)
+    try FileManager.default.createDirectory(at: tempDir, withIntermediateDirectories: true)
+
+    let unique = UUID().uuidString.prefix(8)
+    let tempUrl = tempDir.appendingPathComponent("\(safeId)_\(unique)_base.\(suffix)")
+    try data.write(to: tempUrl, options: .atomic)
+
+    let sha1 = Data(Insecure.SHA1.hash(data: data)).base64EncodedString()
+    let mime = UTType(resource.uniformTypeIdentifier)?.preferredMIMEType ?? "application/octet-stream"
+    return BaseResource(path: tempUrl.path, sha1: sha1, sizeBytes: Int64(data.count), mimeType: mime)
+  }
+
+  private static func collectResourceData(
+    _ resource: PHAssetResource,
+    allowNetworkAccess: Bool
+  ) async -> Data? {
+    let options = PHAssetResourceRequestOptions()
+    options.isNetworkAccessAllowed = allowNetworkAccess
+    var buffer = Data()
+    return await withCheckedContinuation { (continuation: CheckedContinuation<Data?, Never>) in
+      PHAssetResourceManager.default().requestData(
+        for: resource,
+        options: options,
+        dataReceivedHandler: { data in buffer.append(data) },
+        completionHandler: { error in continuation.resume(returning: error == nil ? buffer : nil) }
+      )
+    }
+  }
+
 }

mobile/lib/constants/constants.dart

@@ -20,6 +20,7 @@ const String kSecuredPinCode = "secured_pin_code";
 const String kManualUploadGroup = 'manual_upload_group';
 const String kBackupGroup = 'backup_group';
 const String kBackupLivePhotoGroup = 'backup_live_photo_group';
+const String kBackupEditPairGroup = 'backup_edit_pair_group';
 const String kDownloadGroupImage = 'group_image';
 const String kDownloadGroupVideo = 'group_video';
 const String kDownloadGroupLivePhoto = 'group_livephoto';

mobile/lib/domain/models/asset/local_asset.model.dart

@@ -12,6 +12,13 @@ class LocalAsset extends BaseAsset {
   final double? latitude;
   final double? longitude;
 
+  // Remote id of this asset's previous upload; used to stack a new edit under it.
+  final String? priorRemoteId;
+
+  // Local checksum at the last sync action; lets backup skip an already-handled
+  // local whose current render hashes fresh (the iOS revert case).
+  final String? syncedChecksum;
+
   const LocalAsset({
     required this.id,
     String? remoteId,
@@ -32,6 +39,8 @@ class LocalAsset extends BaseAsset {
     this.latitude,
     this.longitude,
     required super.isEdited,
+    this.priorRemoteId,
+    this.syncedChecksum,
   }) : remoteAssetId = remoteId;
 
   @override
@@ -120,6 +129,8 @@ class LocalAsset extends BaseAsset {
     double? latitude,
     double? longitude,
     bool? isEdited,
+    String? priorRemoteId,
+    String? syncedChecksum,
   }) {
     return LocalAsset(
       id: id ?? this.id,
@@ -140,6 +151,8 @@ class LocalAsset extends BaseAsset {
       latitude: latitude ?? this.latitude,
       longitude: longitude ?? this.longitude,
       isEdited: isEdited ?? this.isEdited,
+      priorRemoteId: priorRemoteId ?? this.priorRemoteId,
+      syncedChecksum: syncedChecksum ?? this.syncedChecksum,
     );
   }
 }

mobile/lib/domain/services/edit_revert.service.dart

@@ -0,0 +1,130 @@
+import 'dart:async';
+
+import 'package:immich_mobile/domain/models/asset/base_asset.model.dart';
+import 'package:immich_mobile/infrastructure/repositories/local_asset.repository.dart';
+import 'package:immich_mobile/infrastructure/repositories/stack.repository.dart';
+import 'package:immich_mobile/platform/native_sync_api.g.dart';
+import 'package:immich_mobile/repositories/asset_api.repository.dart';
+import 'package:logging/logging.dart';
+
+/// Handles the iOS revert case: the user reverted an edit in Photos, so the local
+/// is no longer an edit but was already uploaded as one. Flips the stack primary
+/// back to the original base (found via prior_remote_id), deletes the edit members,
+/// and marks the local handled so it isn't re-uploaded.
+class EditRevertService {
+  final NativeSyncApi _nativeSyncApi;
+  final DriftStackRepository _stackRepository;
+  final DriftLocalAssetRepository _localAssetRepository;
+  final AssetApiRepository _assetApiRepository;
+  final _log = Logger('EditRevertService');
+
+  EditRevertService({
+    required NativeSyncApi nativeSyncApi,
+    required DriftStackRepository stackRepository,
+    required DriftLocalAssetRepository localAssetRepository,
+    required AssetApiRepository assetApiRepository,
+  }) : _nativeSyncApi = nativeSyncApi,
+       _stackRepository = stackRepository,
+       _localAssetRepository = localAssetRepository,
+       _assetApiRepository = assetApiRepository;
+
+  /// Returns true if the asset was a revert and was handled (caller skips the
+  /// upload); false to fall through to the normal upload path.
+  Future<bool> tryDedupRevert(LocalAsset asset) async {
+    if (asset.priorRemoteId == null) {
+      return false;
+    }
+
+    // Only a confirmed "no live edit" counts as a revert. `edited` means a fresh
+    // edit, so bail and let the pair flow handle it. `unknown` means the native
+    // side couldn't read the adjustment (e.g. the asset is offloaded to iCloud and
+    // we didn't allow network); bail there too rather than risk treating an edit we
+    // simply couldn't read as a revert and deleting it. allowNetworkAccess=false
+    // keeps this a cheap, offline metadata read.
+    try {
+      final editState = await _nativeSyncApi.getEditState(asset.id, allowNetworkAccess: false);
+      if (editState != EditState.notEdited) {
+        return false;
+      }
+    } catch (error, stack) {
+      _log.warning("edit-state probe failed for ${asset.id}", error, stack);
+      return false;
+    }
+
+    // No live edit, but this local was uploaded as an edit before → revert. iOS
+    // re-encodes a reverted render to fresh bytes that match nothing remote, so we
+    // never try to checksum-match. Flip the stack by structure: prior_remote_id is
+    // the latest edit (the stack primary); flip back to the stack's original base.
+    final String stackId;
+    final String baseId;
+    try {
+      final foundStack = await _stackRepository.findStackIdByRemoteId(asset.priorRemoteId!);
+      if (foundStack == null) {
+        return false;
+      }
+      final base = await _stackRepository.findStackBaseId(foundStack, excludeId: asset.priorRemoteId!);
+      if (base == null) {
+        return false;
+      }
+      stackId = foundStack;
+      baseId = base;
+    } catch (error, stack) {
+      _log.warning("revert stack lookup failed for ${asset.id}", error, stack);
+      return false;
+    }
+
+    try {
+      await _assetApiRepository.setStackPrimary(stackId, baseId);
+      await _stackRepository.setPrimary(stackId, baseId);
+      await _localAssetRepository.markSynced(asset.id, priorRemoteId: baseId, syncedChecksum: asset.checksum ?? '');
+    } catch (error, stack) {
+      _log.warning("revert primary flip failed for ${asset.id}", error, stack);
+      return false;
+    }
+
+    await _tearDownStackAfterFlip(stackId, baseId);
+    return true;
+  }
+
+  /// Finishes what [HashService] started: when a local checksum directly matched
+  /// a non-primary stack member and the primary was already flipped, drop the
+  /// other (now-stale) members.
+  Future<void> finishReconcile({required String stackId, required String newPrimaryId}) async {
+    await _tearDownStackAfterFlip(stackId, newPrimaryId);
+  }
+
+  // Trash the other stack members on the server, unstack, and mirror the result
+  // locally. Each step is best-effort — the flipped primary is the load-bearing
+  // change; the cleanup just tidies up.
+  Future<void> _tearDownStackAfterFlip(String stackId, String keepId) async {
+    final List<String> toDelete;
+    try {
+      toDelete = await _stackRepository.getOtherMemberIds(stackId, keepId);
+    } catch (error, stack) {
+      _log.warning("getOtherMemberIds failed for $stackId", error, stack);
+      return;
+    }
+
+    if (toDelete.isNotEmpty) {
+      try {
+        // Move the stale edit members to the trash rather than deleting outright,
+        // so a revert stays recoverable on the server (force: false = trash).
+        await _assetApiRepository.delete(toDelete, false);
+      } catch (error, stack) {
+        _log.warning("trashing reverted edit members failed for $toDelete", error, stack);
+      }
+    }
+
+    try {
+      await _assetApiRepository.unStack([stackId]);
+    } catch (error, stack) {
+      _log.warning("unstack failed for $stackId", error, stack);
+    }
+
+    try {
+      await _stackRepository.applyRevertCleanup(stackId, toDelete);
+    } catch (error, stack) {
+      _log.warning("local cleanup failed for $stackId", error, stack);
+    }
+  }
+}

mobile/lib/domain/services/hash.service.dart

@@ -2,11 +2,14 @@ import 'package:flutter/services.dart';
 import 'package:immich_mobile/constants/constants.dart';
 import 'package:immich_mobile/domain/models/album/local_album.model.dart';
 import 'package:immich_mobile/domain/models/asset/base_asset.model.dart';
+import 'package:immich_mobile/domain/services/edit_revert.service.dart';
 import 'package:immich_mobile/extensions/platform_extensions.dart';
 import 'package:immich_mobile/infrastructure/repositories/local_album.repository.dart';
 import 'package:immich_mobile/infrastructure/repositories/local_asset.repository.dart';
+import 'package:immich_mobile/infrastructure/repositories/stack.repository.dart';
 import 'package:immich_mobile/infrastructure/repositories/trashed_local_asset.repository.dart';
 import 'package:immich_mobile/platform/native_sync_api.g.dart';
+import 'package:immich_mobile/repositories/asset_api.repository.dart';
 import 'package:logging/logging.dart';
 
 const String _kHashCancelledCode = "HASH_CANCELLED";
@@ -17,6 +20,9 @@ class HashService {
   final DriftLocalAssetRepository _localAssetRepository;
   final DriftTrashedLocalAssetRepository _trashedLocalAssetRepository;
   final NativeSyncApi _nativeSyncApi;
+  final DriftStackRepository _stackRepository;
+  final AssetApiRepository _assetApiRepository;
+  final EditRevertService _editRevertService;
   final bool Function()? _cancelChecker;
   final _log = Logger('HashService');
 
@@ -25,6 +31,9 @@ class HashService {
     required DriftLocalAssetRepository localAssetRepository,
     required DriftTrashedLocalAssetRepository trashedLocalAssetRepository,
     required NativeSyncApi nativeSyncApi,
+    required DriftStackRepository stackRepository,
+    required AssetApiRepository assetApiRepository,
+    required EditRevertService editRevertService,
     bool Function()? cancelChecker,
     int? batchSize,
   }) : _localAlbumRepository = localAlbumRepository,
@@ -32,6 +41,9 @@ class HashService {
        _trashedLocalAssetRepository = trashedLocalAssetRepository,
        _cancelChecker = cancelChecker,
        _nativeSyncApi = nativeSyncApi,
+       _stackRepository = stackRepository,
+       _assetApiRepository = assetApiRepository,
+       _editRevertService = editRevertService,
        _batchSize = batchSize ?? kBatchHashFileLimit;
 
   bool get isCancelled => _cancelChecker?.call() ?? false;
@@ -45,6 +57,7 @@ class HashService {
 
       // Sorted by backupSelection followed by isCloud
       final localAlbums = await _localAlbumRepository.getBackupAlbums();
+      final hashedIds = <String>{};
 
       for (final album in localAlbums) {
         if (isCancelled) {
@@ -54,7 +67,7 @@ class HashService {
 
         final assetsToHash = await _localAlbumRepository.getAssetsToHash(album.id);
         if (assetsToHash.isNotEmpty) {
-          await _hashAssets(album, assetsToHash);
+          await _hashAssets(album, assetsToHash, hashedIds: hashedIds);
         }
       }
       if (CurrentPlatform.isAndroid && localAlbums.isNotEmpty) {
@@ -62,9 +75,15 @@ class HashService {
         final trashedToHash = await _trashedLocalAssetRepository.getAssetsToHash(backupAlbumIds);
         if (trashedToHash.isNotEmpty) {
           final pseudoAlbum = LocalAlbum(id: '-pseudoAlbum', name: 'Trash', updatedAt: DateTime.now());
-          await _hashAssets(pseudoAlbum, trashedToHash, isTrashed: true);
+          await _hashAssets(pseudoAlbum, trashedToHash, isTrashed: true, hashedIds: hashedIds);
         }
       }
+
+      // iOS revert reconcile: a reverted edit re-hashes back to the original's
+      // bytes, which already exist as the stack base — flip the primary to it.
+      if (CurrentPlatform.isIOS && hashedIds.isNotEmpty && !isCancelled) {
+        await _reconcileReverts(hashedIds);
+      }
     } on PlatformException catch (e) {
       if (e.code == _kHashCancelledCode) {
         _log.warning("Hashing cancelled by platform");
@@ -81,7 +100,12 @@ class HashService {
   /// Processes a list of [LocalAsset]s, storing their hash and updating the assets in the DB
   /// with hash for those that were successfully hashed. Hashes are looked up in a table
   /// [LocalAssetHashEntity] by local id. Only missing entries are newly hashed and added to the DB.
-  Future<void> _hashAssets(LocalAlbum album, List<LocalAsset> assetsToHash, {bool isTrashed = false}) async {
+  Future<void> _hashAssets(
+    LocalAlbum album,
+    List<LocalAsset> assetsToHash, {
+    bool isTrashed = false,
+    required Set<String> hashedIds,
+  }) async {
     final toHash = <String, LocalAsset>{};
 
     for (final asset in assetsToHash) {
@@ -92,16 +116,21 @@ class HashService {
 
       toHash[asset.id] = asset;
       if (toHash.length == _batchSize) {
-        await _processBatch(album, toHash, isTrashed);
+        await _processBatch(album, toHash, isTrashed, hashedIds);
         toHash.clear();
       }
     }
 
-    await _processBatch(album, toHash, isTrashed);
+    await _processBatch(album, toHash, isTrashed, hashedIds);
   }
 
   /// Processes a batch of assets.
-  Future<void> _processBatch(LocalAlbum album, Map<String, LocalAsset> toHash, bool isTrashed) async {
+  Future<void> _processBatch(
+    LocalAlbum album,
+    Map<String, LocalAsset> toHash,
+    bool isTrashed,
+    Set<String> hashedIds,
+  ) async {
     if (toHash.isEmpty) {
       return;
     }
@@ -141,5 +170,34 @@ class HashService {
     } else {
       await _localAssetRepository.updateHashes(hashed);
     }
+    hashedIds.addAll(hashed.keys);
+  }
+
+  Future<void> _reconcileReverts(Set<String> localIds) async {
+    final List<StackReconcileTarget> targets;
+    try {
+      targets = await _stackRepository.findRevertReconcileTargets(localIds);
+    } catch (error, stack) {
+      _log.warning("findRevertReconcileTargets failed", error, stack);
+      return;
+    }
+
+    for (final target in targets) {
+      try {
+        await _assetApiRepository.setStackPrimary(target.stackId, target.newPrimaryId);
+        await _stackRepository.setPrimary(target.stackId, target.newPrimaryId);
+        // Roll priorRemoteId forward to the new primary (the matched member) so a
+        // later edit stacks onto THAT instead of the soon-deleted old primary.
+        await _localAssetRepository.markSynced(
+          target.localAssetId,
+          priorRemoteId: target.newPrimaryId,
+          syncedChecksum: target.localAssetChecksum,
+        );
+      } catch (error, stack) {
+        _log.warning("revert reconcile flip failed for stack ${target.stackId}", error, stack);
+        continue;
+      }
+      await _editRevertService.finishReconcile(stackId: target.stackId, newPrimaryId: target.newPrimaryId);
+    }
   }
 }

mobile/lib/domain/utils/background_sync.dart

@@ -186,6 +186,22 @@ class BackgroundSyncManager {
         });
   }
 
+  /// Runs a remote sync guaranteed to observe changes up to now. [syncRemote]
+  /// joins an in-flight sync whose snapshot can pre-date a just-received change
+  /// (e.g. a stack update) and miss it, so wait for any in-flight sync to finish
+  /// first, then run a fresh one.
+  Future<void> runFreshRemoteSync() async {
+    final inflight = _syncTask;
+    if (inflight != null) {
+      try {
+        await inflight.future;
+      } catch (_) {
+        // The in-flight sync's outcome doesn't matter; we only need a fresh one after it.
+      }
+    }
+    await syncRemote();
+  }
+
   Future<void> syncWebsocketBatchV1(List<dynamic> batchData) {
     if (_syncWebsocketTask != null) {
       return _syncWebsocketTask!.future;

mobile/lib/infrastructure/entities/local_asset.entity.dart

@@ -27,6 +27,14 @@ class LocalAssetEntity extends Table with DriftDefaultsMixin, AssetEntityMixin {
 
   IntColumn get playbackStyle => intEnum<AssetPlaybackStyle>().withDefault(const Constant(0))();
 
+  // remote id of the previous upload (iOS edit-pair stacking)
+  TextColumn get priorRemoteId => text().nullable()();
+
+  // local checksum at the last sync action. Lets the backup query skip a local
+  // whose current hash matches nothing remote but is still "handled" — the iOS
+  // revert case, where the reverted render hashes fresh but is already reconciled.
+  TextColumn get syncedChecksum => text().nullable()();
+
   @override
   Set<Column> get primaryKey => {id};
 }
@@ -51,5 +59,7 @@ extension LocalAssetEntityDataDomainExtension on LocalAssetEntityData {
     longitude: longitude,
     cloudId: iCloudId,
     isEdited: false,
+    priorRemoteId: priorRemoteId,
+    syncedChecksum: syncedChecksum,
   );
 }

mobile/lib/infrastructure/entities/local_asset.entity.drift.dart

@@ -26,6 +26,8 @@ typedef $$LocalAssetEntityTableCreateCompanionBuilder =
       i0.Value<double?> latitude,
       i0.Value<double?> longitude,
       i0.Value<i2.AssetPlaybackStyle> playbackStyle,
+      i0.Value<String?> priorRemoteId,
+      i0.Value<String?> syncedChecksum,
     });
 typedef $$LocalAssetEntityTableUpdateCompanionBuilder =
     i1.LocalAssetEntityCompanion Function({
@@ -45,6 +47,8 @@ typedef $$LocalAssetEntityTableUpdateCompanionBuilder =
       i0.Value<double?> latitude,
       i0.Value<double?> longitude,
       i0.Value<i2.AssetPlaybackStyle> playbackStyle,
+      i0.Value<String?> priorRemoteId,
+      i0.Value<String?> syncedChecksum,
     });
 
 class $$LocalAssetEntityTableFilterComposer
@@ -141,6 +145,16 @@ class $$LocalAssetEntityTableFilterComposer
     column: $table.playbackStyle,
     builder: (column) => i0.ColumnWithTypeConverterFilters(column),
   );
+
+  i0.ColumnFilters<String> get priorRemoteId => $composableBuilder(
+    column: $table.priorRemoteId,
+    builder: (column) => i0.ColumnFilters(column),
+  );
+
+  i0.ColumnFilters<String> get syncedChecksum => $composableBuilder(
+    column: $table.syncedChecksum,
+    builder: (column) => i0.ColumnFilters(column),
+  );
 }
 
 class $$LocalAssetEntityTableOrderingComposer
@@ -231,6 +245,16 @@ class $$LocalAssetEntityTableOrderingComposer
     column: $table.playbackStyle,
     builder: (column) => i0.ColumnOrderings(column),
   );
+
+  i0.ColumnOrderings<String> get priorRemoteId => $composableBuilder(
+    column: $table.priorRemoteId,
+    builder: (column) => i0.ColumnOrderings(column),
+  );
+
+  i0.ColumnOrderings<String> get syncedChecksum => $composableBuilder(
+    column: $table.syncedChecksum,
+    builder: (column) => i0.ColumnOrderings(column),
+  );
 }
 
 class $$LocalAssetEntityTableAnnotationComposer
@@ -300,6 +324,16 @@ class $$LocalAssetEntityTableAnnotationComposer
     column: $table.playbackStyle,
     builder: (column) => column,
   );
+
+  i0.GeneratedColumn<String> get priorRemoteId => $composableBuilder(
+    column: $table.priorRemoteId,
+    builder: (column) => column,
+  );
+
+  i0.GeneratedColumn<String> get syncedChecksum => $composableBuilder(
+    column: $table.syncedChecksum,
+    builder: (column) => column,
+  );
 }
 
 class $$LocalAssetEntityTableTableManager
@@ -359,6 +393,8 @@ class $$LocalAssetEntityTableTableManager
                 i0.Value<double?> longitude = const i0.Value.absent(),
                 i0.Value<i2.AssetPlaybackStyle> playbackStyle =
                     const i0.Value.absent(),
+                i0.Value<String?> priorRemoteId = const i0.Value.absent(),
+                i0.Value<String?> syncedChecksum = const i0.Value.absent(),
               }) => i1.LocalAssetEntityCompanion(
                 name: name,
                 type: type,
@@ -376,6 +412,8 @@ class $$LocalAssetEntityTableTableManager
                 latitude: latitude,
                 longitude: longitude,
                 playbackStyle: playbackStyle,
+                priorRemoteId: priorRemoteId,
+                syncedChecksum: syncedChecksum,
               ),
           createCompanionCallback:
               ({
@@ -396,6 +434,8 @@ class $$LocalAssetEntityTableTableManager
                 i0.Value<double?> longitude = const i0.Value.absent(),
                 i0.Value<i2.AssetPlaybackStyle> playbackStyle =
                     const i0.Value.absent(),
+                i0.Value<String?> priorRemoteId = const i0.Value.absent(),
+                i0.Value<String?> syncedChecksum = const i0.Value.absent(),
               }) => i1.LocalAssetEntityCompanion.insert(
                 name: name,
                 type: type,
@@ -413,6 +453,8 @@ class $$LocalAssetEntityTableTableManager
                 latitude: latitude,
                 longitude: longitude,
                 playbackStyle: playbackStyle,
+                priorRemoteId: priorRemoteId,
+                syncedChecksum: syncedChecksum,
               ),
           withReferenceMapper: (p0) => p0
               .map((e) => (e.readTable(table), i0.BaseReferences(db, table, e)))
@@ -637,6 +679,28 @@ class $LocalAssetEntityTable extends i3.LocalAssetEntity
       ).withConverter<i2.AssetPlaybackStyle>(
         i1.$LocalAssetEntityTable.$converterplaybackStyle,
       );
+  static const i0.VerificationMeta _priorRemoteIdMeta =
+      const i0.VerificationMeta('priorRemoteId');
+  @override
+  late final i0.GeneratedColumn<String> priorRemoteId =
+      i0.GeneratedColumn<String>(
+        'prior_remote_id',
+        aliasedName,
+        true,
+        type: i0.DriftSqlType.string,
+        requiredDuringInsert: false,
+      );
+  static const i0.VerificationMeta _syncedChecksumMeta =
+      const i0.VerificationMeta('syncedChecksum');
+  @override
+  late final i0.GeneratedColumn<String> syncedChecksum =
+      i0.GeneratedColumn<String>(
+        'synced_checksum',
+        aliasedName,
+        true,
+        type: i0.DriftSqlType.string,
+        requiredDuringInsert: false,
+      );
   @override
   List<i0.GeneratedColumn> get $columns => [
     name,
@@ -655,6 +719,8 @@ class $LocalAssetEntityTable extends i3.LocalAssetEntity
     latitude,
     longitude,
     playbackStyle,
+    priorRemoteId,
+    syncedChecksum,
   ];
   @override
   String get aliasedName => _alias ?? actualTableName;
@@ -759,6 +825,24 @@ class $LocalAssetEntityTable extends i3.LocalAssetEntity
         longitude.isAcceptableOrUnknown(data['longitude']!, _longitudeMeta),
       );
     }
+    if (data.containsKey('prior_remote_id')) {
+      context.handle(
+        _priorRemoteIdMeta,
+        priorRemoteId.isAcceptableOrUnknown(
+          data['prior_remote_id']!,
+          _priorRemoteIdMeta,
+        ),
+      );
+    }
+    if (data.containsKey('synced_checksum')) {
+      context.handle(
+        _syncedChecksumMeta,
+        syncedChecksum.isAcceptableOrUnknown(
+          data['synced_checksum']!,
+          _syncedChecksumMeta,
+        ),
+      );
+    }
     return context;
   }
 
@@ -839,6 +923,14 @@ class $LocalAssetEntityTable extends i3.LocalAssetEntity
           data['${effectivePrefix}playback_style'],
         )!,
       ),
+      priorRemoteId: attachedDatabase.typeMapping.read(
+        i0.DriftSqlType.string,
+        data['${effectivePrefix}prior_remote_id'],
+      ),
+      syncedChecksum: attachedDatabase.typeMapping.read(
+        i0.DriftSqlType.string,
+        data['${effectivePrefix}synced_checksum'],
+      ),
     );
   }
 
@@ -877,6 +969,8 @@ class LocalAssetEntityData extends i0.DataClass
   final double? latitude;
   final double? longitude;
   final i2.AssetPlaybackStyle playbackStyle;
+  final String? priorRemoteId;
+  final String? syncedChecksum;
   const LocalAssetEntityData({
     required this.name,
     required this.type,
@@ -894,6 +988,8 @@ class LocalAssetEntityData extends i0.DataClass
     this.latitude,
     this.longitude,
     required this.playbackStyle,
+    this.priorRemoteId,
+    this.syncedChecksum,
   });
   @override
   Map<String, i0.Expression> toColumns(bool nullToAbsent) {
@@ -938,6 +1034,12 @@ class LocalAssetEntityData extends i0.DataClass
         i1.$LocalAssetEntityTable.$converterplaybackStyle.toSql(playbackStyle),
       );
     }
+    if (!nullToAbsent || priorRemoteId != null) {
+      map['prior_remote_id'] = i0.Variable<String>(priorRemoteId);
+    }
+    if (!nullToAbsent || syncedChecksum != null) {
+      map['synced_checksum'] = i0.Variable<String>(syncedChecksum);
+    }
     return map;
   }
 
@@ -967,6 +1069,8 @@ class LocalAssetEntityData extends i0.DataClass
       playbackStyle: i1.$LocalAssetEntityTable.$converterplaybackStyle.fromJson(
         serializer.fromJson<int>(json['playbackStyle']),
       ),
+      priorRemoteId: serializer.fromJson<String?>(json['priorRemoteId']),
+      syncedChecksum: serializer.fromJson<String?>(json['syncedChecksum']),
     );
   }
   @override
@@ -993,6 +1097,8 @@ class LocalAssetEntityData extends i0.DataClass
       'playbackStyle': serializer.toJson<int>(
         i1.$LocalAssetEntityTable.$converterplaybackStyle.toJson(playbackStyle),
       ),
+      'priorRemoteId': serializer.toJson<String?>(priorRemoteId),
+      'syncedChecksum': serializer.toJson<String?>(syncedChecksum),
     };
   }
 
@@ -1013,6 +1119,8 @@ class LocalAssetEntityData extends i0.DataClass
     i0.Value<double?> latitude = const i0.Value.absent(),
     i0.Value<double?> longitude = const i0.Value.absent(),
     i2.AssetPlaybackStyle? playbackStyle,
+    i0.Value<String?> priorRemoteId = const i0.Value.absent(),
+    i0.Value<String?> syncedChecksum = const i0.Value.absent(),
   }) => i1.LocalAssetEntityData(
     name: name ?? this.name,
     type: type ?? this.type,
@@ -1032,6 +1140,12 @@ class LocalAssetEntityData extends i0.DataClass
     latitude: latitude.present ? latitude.value : this.latitude,
     longitude: longitude.present ? longitude.value : this.longitude,
     playbackStyle: playbackStyle ?? this.playbackStyle,
+    priorRemoteId: priorRemoteId.present
+        ? priorRemoteId.value
+        : this.priorRemoteId,
+    syncedChecksum: syncedChecksum.present
+        ? syncedChecksum.value
+        : this.syncedChecksum,
   );
   LocalAssetEntityData copyWithCompanion(i1.LocalAssetEntityCompanion data) {
     return LocalAssetEntityData(
@@ -1061,6 +1175,12 @@ class LocalAssetEntityData extends i0.DataClass
       playbackStyle: data.playbackStyle.present
           ? data.playbackStyle.value
           : this.playbackStyle,
+      priorRemoteId: data.priorRemoteId.present
+          ? data.priorRemoteId.value
+          : this.priorRemoteId,
+      syncedChecksum: data.syncedChecksum.present
+          ? data.syncedChecksum.value
+          : this.syncedChecksum,
     );
   }
 
@@ -1082,7 +1202,9 @@ class LocalAssetEntityData extends i0.DataClass
           ..write('adjustmentTime: $adjustmentTime, ')
           ..write('latitude: $latitude, ')
           ..write('longitude: $longitude, ')
-          ..write('playbackStyle: $playbackStyle')
+          ..write('playbackStyle: $playbackStyle, ')
+          ..write('priorRemoteId: $priorRemoteId, ')
+          ..write('syncedChecksum: $syncedChecksum')
           ..write(')'))
         .toString();
   }
@@ -1105,6 +1227,8 @@ class LocalAssetEntityData extends i0.DataClass
     latitude,
     longitude,
     playbackStyle,
+    priorRemoteId,
+    syncedChecksum,
   );
   @override
   bool operator ==(Object other) =>
@@ -1125,7 +1249,9 @@ class LocalAssetEntityData extends i0.DataClass
           other.adjustmentTime == this.adjustmentTime &&
           other.latitude == this.latitude &&
           other.longitude == this.longitude &&
-          other.playbackStyle == this.playbackStyle);
+          other.playbackStyle == this.playbackStyle &&
+          other.priorRemoteId == this.priorRemoteId &&
+          other.syncedChecksum == this.syncedChecksum);
 }
 
 class LocalAssetEntityCompanion
@@ -1146,6 +1272,8 @@ class LocalAssetEntityCompanion
   final i0.Value<double?> latitude;
   final i0.Value<double?> longitude;
   final i0.Value<i2.AssetPlaybackStyle> playbackStyle;
+  final i0.Value<String?> priorRemoteId;
+  final i0.Value<String?> syncedChecksum;
   const LocalAssetEntityCompanion({
     this.name = const i0.Value.absent(),
     this.type = const i0.Value.absent(),
@@ -1163,6 +1291,8 @@ class LocalAssetEntityCompanion
     this.latitude = const i0.Value.absent(),
     this.longitude = const i0.Value.absent(),
     this.playbackStyle = const i0.Value.absent(),
+    this.priorRemoteId = const i0.Value.absent(),
+    this.syncedChecksum = const i0.Value.absent(),
   });
   LocalAssetEntityCompanion.insert({
     required String name,
@@ -1181,6 +1311,8 @@ class LocalAssetEntityCompanion
     this.latitude = const i0.Value.absent(),
     this.longitude = const i0.Value.absent(),
     this.playbackStyle = const i0.Value.absent(),
+    this.priorRemoteId = const i0.Value.absent(),
+    this.syncedChecksum = const i0.Value.absent(),
   }) : name = i0.Value(name),
        type = i0.Value(type),
        id = i0.Value(id);
@@ -1201,6 +1333,8 @@ class LocalAssetEntityCompanion
     i0.Expression<double>? latitude,
     i0.Expression<double>? longitude,
     i0.Expression<int>? playbackStyle,
+    i0.Expression<String>? priorRemoteId,
+    i0.Expression<String>? syncedChecksum,
   }) {
     return i0.RawValuesInsertable({
       if (name != null) 'name': name,
@@ -1219,6 +1353,8 @@ class LocalAssetEntityCompanion
       if (latitude != null) 'latitude': latitude,
       if (longitude != null) 'longitude': longitude,
       if (playbackStyle != null) 'playback_style': playbackStyle,
+      if (priorRemoteId != null) 'prior_remote_id': priorRemoteId,
+      if (syncedChecksum != null) 'synced_checksum': syncedChecksum,
     });
   }
 
@@ -1239,6 +1375,8 @@ class LocalAssetEntityCompanion
     i0.Value<double?>? latitude,
     i0.Value<double?>? longitude,
     i0.Value<i2.AssetPlaybackStyle>? playbackStyle,
+    i0.Value<String?>? priorRemoteId,
+    i0.Value<String?>? syncedChecksum,
   }) {
     return i1.LocalAssetEntityCompanion(
       name: name ?? this.name,
@@ -1257,6 +1395,8 @@ class LocalAssetEntityCompanion
       latitude: latitude ?? this.latitude,
       longitude: longitude ?? this.longitude,
       playbackStyle: playbackStyle ?? this.playbackStyle,
+      priorRemoteId: priorRemoteId ?? this.priorRemoteId,
+      syncedChecksum: syncedChecksum ?? this.syncedChecksum,
     );
   }
 
@@ -1317,6 +1457,12 @@ class LocalAssetEntityCompanion
         ),
       );
     }
+    if (priorRemoteId.present) {
+      map['prior_remote_id'] = i0.Variable<String>(priorRemoteId.value);
+    }
+    if (syncedChecksum.present) {
+      map['synced_checksum'] = i0.Variable<String>(syncedChecksum.value);
+    }
     return map;
   }
 
@@ -1338,7 +1484,9 @@ class LocalAssetEntityCompanion
           ..write('adjustmentTime: $adjustmentTime, ')
           ..write('latitude: $latitude, ')
           ..write('longitude: $longitude, ')
-          ..write('playbackStyle: $playbackStyle')
+          ..write('playbackStyle: $playbackStyle, ')
+          ..write('priorRemoteId: $priorRemoteId, ')
+          ..write('syncedChecksum: $syncedChecksum')
           ..write(')'))
         .toString();
   }

mobile/lib/infrastructure/entities/merged_asset.drift

@@ -83,6 +83,13 @@ AND NOT EXISTS (
     INNER JOIN local_album_entity la on laa.album_id = la.id
     WHERE laa.asset_id = lae.id AND la.backup_selection = 2 -- excluded
 )
+-- iOS edit-in-progress / revert: if this local was already uploaded (its
+-- prior_remote_id resolves to a live remote), hide the local tile so the remote
+-- (the edit, or the flipped-back original) is the single source of truth. Kills
+-- the transient 2-tile flicker and stops a reverted local from re-appearing.
+AND NOT EXISTS (
+	SELECT 1 FROM remote_asset_entity rae WHERE rae.id = lae.prior_remote_id AND rae.owner_id IN :user_ids
+)
 ORDER BY created_at DESC
 LIMIT $limit;
 
@@ -136,6 +143,10 @@ FROM
 		INNER JOIN local_album_entity la on laa.album_id = la.id
 		WHERE laa.asset_id = lae.id AND la.backup_selection = 2 -- excluded
 	)
+	-- iOS edit-in-progress / revert: hide a local already represented by a live remote.
+	AND NOT EXISTS (
+		SELECT 1 FROM remote_asset_entity rae WHERE rae.id = lae.prior_remote_id AND rae.owner_id IN :user_ids
+	)
 )
 GROUP BY bucket_date
 ORDER BY bucket_date DESC;

mobile/lib/infrastructure/entities/merged_asset.drift.dart

@@ -29,7 +29,7 @@ class MergedAssetDrift extends i1.ModularAccessor {
     );
     $arrayStartIndex += generatedlimit.amountOfVariables;
     return customSelect(
-      'SELECT rae.id AS remote_id, (SELECT lae.id FROM local_asset_entity AS lae WHERE lae.checksum = rae.checksum LIMIT 1) AS local_id, rae.name, rae.type, rae.created_at AS created_at, rae.updated_at, rae.width, rae.height, rae.duration_ms, rae.is_favorite, rae.thumb_hash, rae.checksum, rae.owner_id, rae.live_photo_video_id, 0 AS orientation, rae.stack_id, NULL AS i_cloud_id, NULL AS latitude, NULL AS longitude, NULL AS adjustmentTime, rae.is_edited, 0 AS playback_style, rae.uploaded_at FROM remote_asset_entity AS rae LEFT JOIN stack_entity AS se ON rae.stack_id = se.id WHERE rae.deleted_at IS NULL AND rae.visibility = 0 AND rae.owner_id IN ($expandeduserIds) AND(rae.stack_id IS NULL OR rae.id = se.primary_asset_id)UNION ALL SELECT NULL AS remote_id, lae.id AS local_id, lae.name, lae.type, lae.created_at AS created_at, lae.updated_at, lae.width, lae.height, lae.duration_ms, lae.is_favorite, NULL AS thumb_hash, lae.checksum, NULL AS owner_id, NULL AS live_photo_video_id, lae.orientation, NULL AS stack_id, lae.i_cloud_id, lae.latitude, lae.longitude, lae.adjustment_time, 0 AS is_edited, lae.playback_style, NULL AS uploaded_at FROM local_asset_entity AS lae WHERE NOT EXISTS (SELECT 1 FROM remote_asset_entity AS rae WHERE rae.checksum = lae.checksum AND rae.owner_id IN ($expandeduserIds)) AND EXISTS (SELECT 1 FROM local_album_asset_entity AS laa INNER JOIN local_album_entity AS la ON laa.album_id = la.id WHERE laa.asset_id = lae.id AND la.backup_selection = 0) AND NOT EXISTS (SELECT 1 FROM local_album_asset_entity AS laa INNER JOIN local_album_entity AS la ON laa.album_id = la.id WHERE laa.asset_id = lae.id AND la.backup_selection = 2) ORDER BY created_at DESC ${generatedlimit.sql}',
+      'SELECT rae.id AS remote_id, (SELECT lae.id FROM local_asset_entity AS lae WHERE lae.checksum = rae.checksum LIMIT 1) AS local_id, rae.name, rae.type, rae.created_at AS created_at, rae.updated_at, rae.width, rae.height, rae.duration_ms, rae.is_favorite, rae.thumb_hash, rae.checksum, rae.owner_id, rae.live_photo_video_id, 0 AS orientation, rae.stack_id, NULL AS i_cloud_id, NULL AS latitude, NULL AS longitude, NULL AS adjustmentTime, rae.is_edited, 0 AS playback_style, rae.uploaded_at FROM remote_asset_entity AS rae LEFT JOIN stack_entity AS se ON rae.stack_id = se.id WHERE rae.deleted_at IS NULL AND rae.visibility = 0 AND rae.owner_id IN ($expandeduserIds) AND(rae.stack_id IS NULL OR rae.id = se.primary_asset_id)UNION ALL SELECT NULL AS remote_id, lae.id AS local_id, lae.name, lae.type, lae.created_at AS created_at, lae.updated_at, lae.width, lae.height, lae.duration_ms, lae.is_favorite, NULL AS thumb_hash, lae.checksum, NULL AS owner_id, NULL AS live_photo_video_id, lae.orientation, NULL AS stack_id, lae.i_cloud_id, lae.latitude, lae.longitude, lae.adjustment_time, 0 AS is_edited, lae.playback_style, NULL AS uploaded_at FROM local_asset_entity AS lae WHERE NOT EXISTS (SELECT 1 FROM remote_asset_entity AS rae WHERE rae.checksum = lae.checksum AND rae.owner_id IN ($expandeduserIds)) AND EXISTS (SELECT 1 FROM local_album_asset_entity AS laa INNER JOIN local_album_entity AS la ON laa.album_id = la.id WHERE laa.asset_id = lae.id AND la.backup_selection = 0) AND NOT EXISTS (SELECT 1 FROM local_album_asset_entity AS laa INNER JOIN local_album_entity AS la ON laa.album_id = la.id WHERE laa.asset_id = lae.id AND la.backup_selection = 2) AND NOT EXISTS (SELECT 1 FROM remote_asset_entity AS rae WHERE rae.id = lae.prior_remote_id AND rae.owner_id IN ($expandeduserIds)) ORDER BY created_at DESC ${generatedlimit.sql}',
       variables: [
         for (var $ in userIds) i0.Variable<String>($),
         ...generatedlimit.introducedVariables,
@@ -81,7 +81,7 @@ class MergedAssetDrift extends i1.ModularAccessor {
     final expandeduserIds = $expandVar($arrayStartIndex, userIds.length);
     $arrayStartIndex += userIds.length;
     return customSelect(
-      'SELECT COUNT(*) AS asset_count, bucket_date FROM (SELECT CASE WHEN ?1 = 0 THEN COALESCE(STRFTIME(\'%Y-%m-%d\', rae.local_date_time), STRFTIME(\'%Y-%m-%d\', rae.created_at, \'localtime\')) WHEN ?1 = 1 THEN COALESCE(STRFTIME(\'%Y-%m\', rae.local_date_time), STRFTIME(\'%Y-%m\', rae.created_at, \'localtime\')) END AS bucket_date FROM remote_asset_entity AS rae LEFT JOIN stack_entity AS se ON rae.stack_id = se.id WHERE rae.deleted_at IS NULL AND rae.visibility = 0 AND rae.owner_id IN ($expandeduserIds) AND(rae.stack_id IS NULL OR rae.id = se.primary_asset_id)UNION ALL SELECT CASE WHEN ?1 = 0 THEN STRFTIME(\'%Y-%m-%d\', lae.created_at, \'localtime\') WHEN ?1 = 1 THEN STRFTIME(\'%Y-%m\', lae.created_at, \'localtime\') END AS bucket_date FROM local_asset_entity AS lae WHERE NOT EXISTS (SELECT 1 FROM remote_asset_entity AS rae WHERE rae.checksum = lae.checksum AND rae.owner_id IN ($expandeduserIds)) AND EXISTS (SELECT 1 FROM local_album_asset_entity AS laa INNER JOIN local_album_entity AS la ON laa.album_id = la.id WHERE laa.asset_id = lae.id AND la.backup_selection = 0) AND NOT EXISTS (SELECT 1 FROM local_album_asset_entity AS laa INNER JOIN local_album_entity AS la ON laa.album_id = la.id WHERE laa.asset_id = lae.id AND la.backup_selection = 2)) GROUP BY bucket_date ORDER BY bucket_date DESC',
+      'SELECT COUNT(*) AS asset_count, bucket_date FROM (SELECT CASE WHEN ?1 = 0 THEN COALESCE(STRFTIME(\'%Y-%m-%d\', rae.local_date_time), STRFTIME(\'%Y-%m-%d\', rae.created_at, \'localtime\')) WHEN ?1 = 1 THEN COALESCE(STRFTIME(\'%Y-%m\', rae.local_date_time), STRFTIME(\'%Y-%m\', rae.created_at, \'localtime\')) END AS bucket_date FROM remote_asset_entity AS rae LEFT JOIN stack_entity AS se ON rae.stack_id = se.id WHERE rae.deleted_at IS NULL AND rae.visibility = 0 AND rae.owner_id IN ($expandeduserIds) AND(rae.stack_id IS NULL OR rae.id = se.primary_asset_id)UNION ALL SELECT CASE WHEN ?1 = 0 THEN STRFTIME(\'%Y-%m-%d\', lae.created_at, \'localtime\') WHEN ?1 = 1 THEN STRFTIME(\'%Y-%m\', lae.created_at, \'localtime\') END AS bucket_date FROM local_asset_entity AS lae WHERE NOT EXISTS (SELECT 1 FROM remote_asset_entity AS rae WHERE rae.checksum = lae.checksum AND rae.owner_id IN ($expandeduserIds)) AND EXISTS (SELECT 1 FROM local_album_asset_entity AS laa INNER JOIN local_album_entity AS la ON laa.album_id = la.id WHERE laa.asset_id = lae.id AND la.backup_selection = 0) AND NOT EXISTS (SELECT 1 FROM local_album_asset_entity AS laa INNER JOIN local_album_entity AS la ON laa.album_id = la.id WHERE laa.asset_id = lae.id AND la.backup_selection = 2) AND NOT EXISTS (SELECT 1 FROM remote_asset_entity AS rae WHERE rae.id = lae.prior_remote_id AND rae.owner_id IN ($expandeduserIds))) GROUP BY bucket_date ORDER BY bucket_date DESC',
       variables: [
         i0.Variable<int>(groupBy),
         for (var $ in userIds) i0.Variable<String>($),

mobile/lib/infrastructure/repositories/backup.repository.dart

@@ -58,7 +58,8 @@ class DriftBackupRepository extends DriftDatabaseRepository {
             INNER JOIN main.local_album_entity la on laa.album_id = la.id
             WHERE laa.asset_id = lae.id
                 AND la.backup_selection = ?3
-        );
+        )
+        AND (lae.synced_checksum IS NULL OR lae.synced_checksum != lae.checksum);
       ''';
 
     final row = await _db
@@ -104,6 +105,10 @@ class DriftBackupRepository extends DriftDatabaseRepository {
                   _db.remoteAssetEntity.checksum.equalsExp(lae.checksum) & _db.remoteAssetEntity.ownerId.equals(userId),
                 ),
             ) &
+            // iOS revert: a reverted local hashes fresh (matches nothing remote),
+            // but if it was already reconciled (syncedChecksum == current checksum)
+            // it's handled — don't re-queue it as a fresh upload.
+            (lae.syncedChecksum.isNull() | lae.syncedChecksum.equalsExp(lae.checksum).not()) &
             lae.id.isNotInQuery(_getExcludedSubquery()),
       )
       ..orderBy([(localAsset) => OrderingTerm.desc(localAsset.createdAt)]);

mobile/lib/infrastructure/repositories/db.repository.dart

@@ -98,7 +98,7 @@ class Drift extends $Drift {
   }
 
   @override
-  int get schemaVersion => 26;
+  int get schemaVersion => 28;
 
   @override
   MigrationStrategy get migration => MigrationStrategy(
@@ -276,6 +276,12 @@ class Drift extends $Drift {
           from25To26: (m, v26) async {
             await m.addColumn(v26.remoteAssetEntity, v26.remoteAssetEntity.uploadedAt);
           },
+          from26To27: (m, v27) async {
+            await m.addColumn(v27.localAssetEntity, v27.localAssetEntity.priorRemoteId);
+          },
+          from27To28: (m, v28) async {
+            await m.addColumn(v28.localAssetEntity, v28.localAssetEntity.syncedChecksum);
+          },
         ),
       );
 

mobile/lib/infrastructure/repositories/local_asset.repository.dart

@@ -64,6 +64,12 @@ class DriftLocalAssetRepository extends DriftDatabaseRepository {
     });
   }
 
+  Future<void> markSynced(String localId, {required String priorRemoteId, required String syncedChecksum}) {
+    return (_db.localAssetEntity.update()..where((e) => e.id.equals(localId))).write(
+      LocalAssetEntityCompanion(priorRemoteId: Value(priorRemoteId), syncedChecksum: Value(syncedChecksum)),
+    );
+  }
+
   Future<void> delete(List<String> ids) {
     if (ids.isEmpty) {
       return Future.value();

mobile/lib/infrastructure/repositories/stack.repository.dart

@@ -1,8 +1,25 @@
+import 'package:collection/collection.dart';
 import 'package:drift/drift.dart';
+import 'package:immich_mobile/constants/constants.dart';
 import 'package:immich_mobile/domain/models/stack.model.dart';
+import 'package:immich_mobile/infrastructure/entities/remote_asset.entity.drift.dart';
 import 'package:immich_mobile/infrastructure/entities/stack.entity.drift.dart';
 import 'package:immich_mobile/infrastructure/repositories/db.repository.dart';
 
+class StackReconcileTarget {
+  final String stackId;
+  final String newPrimaryId;
+  final String localAssetId;
+  final String localAssetChecksum;
+
+  const StackReconcileTarget({
+    required this.stackId,
+    required this.newPrimaryId,
+    required this.localAssetId,
+    required this.localAssetChecksum,
+  });
+}
+
 class DriftStackRepository extends DriftDatabaseRepository {
   final Drift _db;
   const DriftStackRepository(this._db) : super(_db);
@@ -14,6 +31,123 @@ class DriftStackRepository extends DriftDatabaseRepository {
       return stack.toDto();
     }).get();
   }
+
+  // Per local id, find a stack member whose checksum matches the local's current
+  // checksum but isn't the stack primary — the iOS revert case where the local
+  // hashed back to the base while the primary still points at the edit.
+  Future<List<StackReconcileTarget>> findRevertReconcileTargets(Iterable<String> localAssetIds) async {
+    final ids = localAssetIds.toSet();
+    if (ids.isEmpty) {
+      return const [];
+    }
+
+    final targets = <StackReconcileTarget>[];
+    for (final slice in ids.slices(kDriftMaxChunk)) {
+      final placeholders = List.filled(slice.length, '?').join(',');
+      final rows = await _db
+          .customSelect(
+            '''
+        SELECT
+          s.id AS stack_id,
+          member.id AS new_primary,
+          local.id AS local_id,
+          local.checksum AS local_checksum
+        FROM local_asset_entity local
+        INNER JOIN remote_asset_entity prior ON prior.id = local.prior_remote_id
+        INNER JOIN stack_entity s ON s.id = prior.stack_id
+        INNER JOIN remote_asset_entity member
+          ON member.stack_id = s.id
+          AND member.checksum = local.checksum
+          AND member.deleted_at IS NULL
+        WHERE local.id IN ($placeholders)
+          AND s.primary_asset_id != member.id
+        ''',
+            variables: slice.map((id) => Variable<String>(id)).toList(),
+            readsFrom: {_db.localAssetEntity, _db.remoteAssetEntity, _db.stackEntity},
+          )
+          .get();
+
+      for (final row in rows) {
+        targets.add(
+          StackReconcileTarget(
+            stackId: row.read<String>('stack_id'),
+            newPrimaryId: row.read<String>('new_primary'),
+            localAssetId: row.read<String>('local_id'),
+            localAssetChecksum: row.read<String>('local_checksum'),
+          ),
+        );
+      }
+    }
+    return targets;
+  }
+
+  // The stack a remote asset belongs to, if any. Used by the revert path to find
+  // the stack from prior_remote_id when the reverted bytes can't be checksum-matched.
+  Future<String?> findStackIdByRemoteId(String remoteId) async {
+    final row = await _db
+        .customSelect(
+          'SELECT stack_id FROM remote_asset_entity WHERE id = ? AND stack_id IS NOT NULL AND deleted_at IS NULL',
+          variables: [Variable<String>(remoteId)],
+          readsFrom: {_db.remoteAssetEntity},
+        )
+        .getSingleOrNull();
+    return row?.read<String?>('stack_id');
+  }
+
+  // The stack's original base member to flip back to on revert: the earliest-
+  // uploaded member that isn't the (latest-edit) prior. The base is uploaded
+  // before its edits, so oldest uploaded_at = the original.
+  Future<String?> findStackBaseId(String stackId, {required String excludeId}) async {
+    final row = await _db
+        .customSelect(
+          '''
+          SELECT id FROM remote_asset_entity
+          WHERE stack_id = ? AND id != ? AND deleted_at IS NULL
+          ORDER BY uploaded_at IS NULL, uploaded_at ASC, id ASC
+          LIMIT 1
+          ''',
+          variables: [Variable<String>(stackId), Variable<String>(excludeId)],
+          readsFrom: {_db.remoteAssetEntity},
+        )
+        .getSingleOrNull();
+    return row?.read<String?>('id');
+  }
+
+  // Optimistic local primary flip so the timeline updates immediately; the
+  // server's stack-update websocket rewrites it shortly after.
+  Future<void> setPrimary(String stackId, String primaryAssetId) {
+    return (_db.stackEntity.update()..where((e) => e.id.equals(stackId))).write(
+      StackEntityCompanion(primaryAssetId: Value(primaryAssetId)),
+    );
+  }
+
+  // Optimistic local cleanup after a revert: detach every member, drop the stack,
+  // and delete the edit assets — atomically, so the timeline never shows members
+  // pointing at a deleted stack.
+  Future<void> applyRevertCleanup(String stackId, List<String> deletedAssetIds) {
+    return _db.batch((batch) {
+      batch.update(
+        _db.remoteAssetEntity,
+        const RemoteAssetEntityCompanion(stackId: Value(null)),
+        where: (e) => e.stackId.equals(stackId),
+      );
+      batch.deleteWhere(_db.stackEntity, (e) => e.id.equals(stackId));
+      for (final id in deletedAssetIds) {
+        batch.deleteWhere(_db.remoteAssetEntity, (e) => e.id.equals(id));
+      }
+    });
+  }
+
+  Future<List<String>> getOtherMemberIds(String stackId, String keepId) async {
+    final rows = await _db
+        .customSelect(
+          'SELECT id FROM remote_asset_entity WHERE stack_id = ? AND id != ? AND deleted_at IS NULL',
+          variables: [Variable<String>(stackId), Variable<String>(keepId)],
+          readsFrom: {_db.remoteAssetEntity},
+        )
+        .get();
+    return rows.map((r) => r.read<String>('id')).toList(growable: false);
+  }
 }
 
 extension on StackEntityData {

mobile/lib/platform/native_sync_api.g.dart

@@ -88,6 +88,8 @@ int _deepHash(Object? value) {
 
 enum PlatformAssetPlaybackStyle { unknown, image, video, imageAnimated, livePhoto, videoLooping }
 
+enum EditState { notEdited, edited, unknown }
+
 class PlatformAsset {
   PlatformAsset({
     required this.id,
@@ -395,6 +397,55 @@ class CloudIdResult {
   int get hashCode => _deepHash(<Object?>[runtimeType, ..._toList()]);
 }
 
+class BaseResource {
+  BaseResource({required this.path, required this.sha1, required this.sizeBytes, required this.mimeType});
+
+  String path;
+
+  String sha1;
+
+  int sizeBytes;
+
+  String mimeType;
+
+  List<Object?> _toList() {
+    return <Object?>[path, sha1, sizeBytes, mimeType];
+  }
+
+  Object encode() {
+    return _toList();
+  }
+
+  static BaseResource decode(Object result) {
+    result as List<Object?>;
+    return BaseResource(
+      path: result[0]! as String,
+      sha1: result[1]! as String,
+      sizeBytes: result[2]! as int,
+      mimeType: result[3]! as String,
+    );
+  }
+
+  @override
+  // ignore: avoid_equals_and_hash_code_on_mutable_classes
+  bool operator ==(Object other) {
+    if (other is! BaseResource || other.runtimeType != runtimeType) {
+      return false;
+    }
+    if (identical(this, other)) {
+      return true;
+    }
+    return _deepEquals(path, other.path) &&
+        _deepEquals(sha1, other.sha1) &&
+        _deepEquals(sizeBytes, other.sizeBytes) &&
+        _deepEquals(mimeType, other.mimeType);
+  }
+
+  @override
+  // ignore: avoid_equals_and_hash_code_on_mutable_classes
+  int get hashCode => _deepHash(<Object?>[runtimeType, ..._toList()]);
+}
+
 class _PigeonCodec extends StandardMessageCodec {
   const _PigeonCodec();
   @override
@@ -405,21 +456,27 @@ class _PigeonCodec extends StandardMessageCodec {
     } else if (value is PlatformAssetPlaybackStyle) {
       buffer.putUint8(129);
       writeValue(buffer, value.index);
-    } else if (value is PlatformAsset) {
+    } else if (value is EditState) {
       buffer.putUint8(130);
-      writeValue(buffer, value.encode());
-    } else if (value is PlatformAlbum) {
+      writeValue(buffer, value.index);
+    } else if (value is PlatformAsset) {
       buffer.putUint8(131);
       writeValue(buffer, value.encode());
-    } else if (value is SyncDelta) {
+    } else if (value is PlatformAlbum) {
       buffer.putUint8(132);
       writeValue(buffer, value.encode());
-    } else if (value is HashResult) {
+    } else if (value is SyncDelta) {
       buffer.putUint8(133);
       writeValue(buffer, value.encode());
-    } else if (value is CloudIdResult) {
+    } else if (value is HashResult) {
       buffer.putUint8(134);
       writeValue(buffer, value.encode());
+    } else if (value is CloudIdResult) {
+      buffer.putUint8(135);
+      writeValue(buffer, value.encode());
+    } else if (value is BaseResource) {
+      buffer.putUint8(136);
+      writeValue(buffer, value.encode());
     } else {
       super.writeValue(buffer, value);
     }
@@ -432,15 +489,20 @@ class _PigeonCodec extends StandardMessageCodec {
         final value = readValue(buffer) as int?;
         return value == null ? null : PlatformAssetPlaybackStyle.values[value];
       case 130:
-        return PlatformAsset.decode(readValue(buffer)!);
+        final value = readValue(buffer) as int?;
+        return value == null ? null : EditState.values[value];
       case 131:
-        return PlatformAlbum.decode(readValue(buffer)!);
+        return PlatformAsset.decode(readValue(buffer)!);
       case 132:
-        return SyncDelta.decode(readValue(buffer)!);
+        return PlatformAlbum.decode(readValue(buffer)!);
       case 133:
-        return HashResult.decode(readValue(buffer)!);
+        return SyncDelta.decode(readValue(buffer)!);
       case 134:
+        return HashResult.decode(readValue(buffer)!);
+      case 135:
         return CloudIdResult.decode(readValue(buffer)!);
+      case 136:
+        return BaseResource.decode(readValue(buffer)!);
       default:
         return super.readValueOfType(type, buffer);
     }
@@ -672,4 +734,42 @@ class NativeSyncApi {
     );
     return (pigeonVar_replyValue! as List<Object?>).cast<CloudIdResult>();
   }
+
+  Future<BaseResource?> getBaseResource(String assetId, {bool allowNetworkAccess = false}) async {
+    final pigeonVar_channelName =
+        'dev.flutter.pigeon.immich_mobile.NativeSyncApi.getBaseResource$pigeonVar_messageChannelSuffix';
+    final pigeonVar_channel = BasicMessageChannel<Object?>(
+      pigeonVar_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: pigeonVar_binaryMessenger,
+    );
+    final Future<Object?> pigeonVar_sendFuture = pigeonVar_channel.send(<Object?>[assetId, allowNetworkAccess]);
+    final pigeonVar_replyList = await pigeonVar_sendFuture as List<Object?>?;
+
+    final Object? pigeonVar_replyValue = _extractReplyValueOrThrow(
+      pigeonVar_replyList,
+      pigeonVar_channelName,
+      isNullValid: true,
+    );
+    return pigeonVar_replyValue as BaseResource?;
+  }
+
+  Future<EditState> getEditState(String assetId, {bool allowNetworkAccess = false}) async {
+    final pigeonVar_channelName =
+        'dev.flutter.pigeon.immich_mobile.NativeSyncApi.getEditState$pigeonVar_messageChannelSuffix';
+    final pigeonVar_channel = BasicMessageChannel<Object?>(
+      pigeonVar_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: pigeonVar_binaryMessenger,
+    );
+    final Future<Object?> pigeonVar_sendFuture = pigeonVar_channel.send(<Object?>[assetId, allowNetworkAccess]);
+    final pigeonVar_replyList = await pigeonVar_sendFuture as List<Object?>?;
+
+    final Object? pigeonVar_replyValue = _extractReplyValueOrThrow(
+      pigeonVar_replyList,
+      pigeonVar_channelName,
+      isNullValid: false,
+    );
+    return pigeonVar_replyValue! as EditState;
+  }
 }

mobile/lib/providers/infrastructure/sync.provider.dart

@@ -1,4 +1,5 @@
 import 'package:hooks_riverpod/hooks_riverpod.dart';
+import 'package:immich_mobile/domain/services/edit_revert.service.dart';
 import 'package:immich_mobile/domain/services/hash.service.dart';
 import 'package:immich_mobile/domain/services/local_sync.service.dart';
 import 'package:immich_mobile/domain/services/sync_stream.service.dart';
@@ -11,7 +12,9 @@ import 'package:immich_mobile/providers/infrastructure/asset.provider.dart';
 import 'package:immich_mobile/providers/infrastructure/cancel.provider.dart';
 import 'package:immich_mobile/providers/infrastructure/db.provider.dart';
 import 'package:immich_mobile/providers/infrastructure/platform.provider.dart';
+import 'package:immich_mobile/providers/infrastructure/stack.provider.dart';
 import 'package:immich_mobile/providers/infrastructure/storage.provider.dart';
+import 'package:immich_mobile/repositories/asset_api.repository.dart';
 import 'package:immich_mobile/repositories/local_files_manager.repository.dart';
 
 final syncMigrationRepositoryProvider = Provider((ref) => SyncMigrationRepository(ref.watch(driftProvider)));
@@ -45,11 +48,23 @@ final localSyncServiceProvider = Provider(
   ),
 );
 
+final editRevertServiceProvider = Provider(
+  (ref) => EditRevertService(
+    nativeSyncApi: ref.watch(nativeSyncApiProvider),
+    stackRepository: ref.watch(driftStackProvider),
+    localAssetRepository: ref.watch(localAssetRepository),
+    assetApiRepository: ref.watch(assetApiRepositoryProvider),
+  ),
+);
+
 final hashServiceProvider = Provider(
   (ref) => HashService(
     localAlbumRepository: ref.watch(localAlbumRepository),
     localAssetRepository: ref.watch(localAssetRepository),
     nativeSyncApi: ref.watch(nativeSyncApiProvider),
     trashedLocalAssetRepository: ref.watch(trashedLocalAssetRepository),
+    stackRepository: ref.watch(driftStackProvider),
+    assetApiRepository: ref.watch(assetApiRepositoryProvider),
+    editRevertService: ref.watch(editRevertServiceProvider),
   ),
 );

mobile/lib/providers/websocket.provider.dart

@@ -105,6 +105,7 @@ class WebsocketNotifier extends StateNotifier<WebsocketState> {
         socket.on('AssetEditReadyV2', _handleSyncAssetEditReadyV2);
         socket.on('on_config_update', _handleOnConfigUpdate);
         socket.on('on_new_release', _handleReleaseUpdates);
+        socket.on('on_asset_stack_update', _handleAssetStackUpdate);
       } catch (e) {
         dPrint(() => "[WEBSOCKET] Catch Websocket Error - ${e.toString()}");
       }
@@ -188,6 +189,13 @@ class WebsocketNotifier extends StateNotifier<WebsocketState> {
     unawaited(_ref.read(backgroundSyncProvider).syncWebsocketEditV2(data));
   }
 
+  // Server stacked/restacked assets (e.g. an edit stacked onto its original).
+  // Pull a fresh remote sync so the stack_entity lands and the timeline shows
+  // the stacked primary instead of briefly hiding the asset.
+  void _handleAssetStackUpdate(dynamic _) {
+    unawaited(_ref.read(backgroundSyncProvider).runFreshRemoteSync());
+  }
+
   void _processBatchedAssetUploadReadyV1() {
     if (_batchedAssetUploadReady.isEmpty) {
       return;

mobile/lib/repositories/asset_api.repository.dart

@@ -67,6 +67,10 @@ class AssetApiRepository extends ApiRepository {
     return _stacksApi.deleteStacks(BulkIdsDto(ids: ids));
   }
 
+  Future<void> setStackPrimary(String stackId, String primaryAssetId) async {
+    await _stacksApi.updateStack(stackId, StackUpdateDto(primaryAssetId: primaryAssetId));
+  }
+
   Future<Response> downloadAsset(String id, {required bool edited}) {
     return _api.downloadAssetWithHttpInfo(id, edited: edited);
   }

mobile/lib/repositories/upload.repository.dart

@@ -30,6 +30,11 @@ class UploadRepository {
       taskStatusCallback: (update) => onUploadStatus?.call(update),
       taskProgressCallback: (update) => onTaskProgress?.call(update),
     );
+    FileDownloader().registerCallbacks(
+      group: kBackupEditPairGroup,
+      taskStatusCallback: (update) => onUploadStatus?.call(update),
+      taskProgressCallback: (update) => onTaskProgress?.call(update),
+    );
     FileDownloader().registerCallbacks(
       group: kManualUploadGroup,
       taskStatusCallback: (update) => onUploadStatus?.call(update),

mobile/lib/services/background_upload.service.dart

@@ -9,14 +9,18 @@ import 'package:immich_mobile/constants/constants.dart';
 import 'package:immich_mobile/domain/models/asset/asset_metadata.model.dart';
 import 'package:immich_mobile/domain/models/asset/base_asset.model.dart';
 import 'package:immich_mobile/domain/models/store.model.dart';
+import 'package:immich_mobile/domain/services/edit_revert.service.dart';
 import 'package:immich_mobile/entities/store.entity.dart';
 import 'package:immich_mobile/extensions/platform_extensions.dart';
 import 'package:immich_mobile/infrastructure/repositories/backup.repository.dart';
 import 'package:immich_mobile/infrastructure/repositories/local_asset.repository.dart';
 import 'package:immich_mobile/infrastructure/repositories/metadata.repository.dart';
 import 'package:immich_mobile/infrastructure/repositories/storage.repository.dart';
+import 'package:immich_mobile/platform/native_sync_api.g.dart';
 import 'package:immich_mobile/providers/infrastructure/asset.provider.dart';
+import 'package:immich_mobile/providers/infrastructure/platform.provider.dart';
 import 'package:immich_mobile/providers/infrastructure/storage.provider.dart';
+import 'package:immich_mobile/providers/infrastructure/sync.provider.dart';
 import 'package:immich_mobile/repositories/asset_media.repository.dart';
 import 'package:immich_mobile/repositories/upload.repository.dart';
 import 'package:immich_mobile/services/api.service.dart';
@@ -31,6 +35,8 @@ final backgroundUploadServiceProvider = Provider((ref) {
     ref.watch(localAssetRepository),
     ref.watch(backupRepositoryProvider),
     ref.watch(assetMediaRepositoryProvider),
+    ref.watch(nativeSyncApiProvider),
+    ref.watch(editRevertServiceProvider),
   );
 
   ref.onDispose(service.dispose);
@@ -43,13 +49,35 @@ class UploadTaskMetadata {
   final bool isLivePhotos;
   final String livePhotoVideoId;
 
-  const UploadTaskMetadata({required this.localAssetId, required this.isLivePhotos, required this.livePhotoVideoId});
+  // Marks the base upload of an edit pair. On completion the chained edit
+  // upload is enqueued with stackParentId = this base's remote id.
+  final bool isEditPair;
 
-  UploadTaskMetadata copyWith({String? localAssetId, bool? isLivePhotos, String? livePhotoVideoId}) {
+  // Path of the native temp file backing this task (the edit base), so it can
+  // be cleaned up on terminal status.
+  final String basePath;
+
+  const UploadTaskMetadata({
+    required this.localAssetId,
+    required this.isLivePhotos,
+    required this.livePhotoVideoId,
+    this.isEditPair = false,
+    this.basePath = '',
+  });
+
+  UploadTaskMetadata copyWith({
+    String? localAssetId,
+    bool? isLivePhotos,
+    String? livePhotoVideoId,
+    bool? isEditPair,
+    String? basePath,
+  }) {
     return UploadTaskMetadata(
       localAssetId: localAssetId ?? this.localAssetId,
       isLivePhotos: isLivePhotos ?? this.isLivePhotos,
       livePhotoVideoId: livePhotoVideoId ?? this.livePhotoVideoId,
+      isEditPair: isEditPair ?? this.isEditPair,
+      basePath: basePath ?? this.basePath,
     );
   }
 
@@ -58,6 +86,8 @@ class UploadTaskMetadata {
       'localAssetId': localAssetId,
       'isLivePhotos': isLivePhotos,
       'livePhotoVideoId': livePhotoVideoId,
+      'isEditPair': isEditPair,
+      'basePath': basePath,
     };
   }
 
@@ -66,6 +96,8 @@ class UploadTaskMetadata {
       localAssetId: map['localAssetId'] as String,
       isLivePhotos: map['isLivePhotos'] as bool,
       livePhotoVideoId: map['livePhotoVideoId'] as String,
+      isEditPair: (map['isEditPair'] as bool?) ?? false,
+      basePath: (map['basePath'] as String?) ?? '',
     );
   }
 
@@ -76,7 +108,7 @@ class UploadTaskMetadata {
 
   @override
   String toString() =>
-      'UploadTaskMetadata(localAssetId: $localAssetId, isLivePhotos: $isLivePhotos, livePhotoVideoId: $livePhotoVideoId)';
+      'UploadTaskMetadata(localAssetId: $localAssetId, isLivePhotos: $isLivePhotos, livePhotoVideoId: $livePhotoVideoId, isEditPair: $isEditPair, basePath: $basePath)';
 
   @override
   bool operator ==(covariant UploadTaskMetadata other) {
@@ -86,11 +118,18 @@ class UploadTaskMetadata {
 
     return other.localAssetId == localAssetId &&
         other.isLivePhotos == isLivePhotos &&
-        other.livePhotoVideoId == livePhotoVideoId;
+        other.livePhotoVideoId == livePhotoVideoId &&
+        other.isEditPair == isEditPair &&
+        other.basePath == basePath;
   }
 
   @override
-  int get hashCode => localAssetId.hashCode ^ isLivePhotos.hashCode ^ livePhotoVideoId.hashCode;
+  int get hashCode =>
+      localAssetId.hashCode ^
+      isLivePhotos.hashCode ^
+      livePhotoVideoId.hashCode ^
+      isEditPair.hashCode ^
+      basePath.hashCode;
 }
 
 /// Service for handling background uploads using iOS URLSession (background_downloader)
@@ -104,6 +143,8 @@ class BackgroundUploadService {
     this._localAssetRepository,
     this._backupRepository,
     this._assetMediaRepository,
+    this._nativeSyncApi,
+    this._editRevertService,
   ) {
     _uploadRepository.onUploadStatus = _onUploadCallback;
     _uploadRepository.onTaskProgress = _onTaskProgressCallback;
@@ -114,6 +155,8 @@ class BackgroundUploadService {
   final DriftLocalAssetRepository _localAssetRepository;
   final DriftBackupRepository _backupRepository;
   final AssetMediaRepository _assetMediaRepository;
+  final NativeSyncApi _nativeSyncApi;
+  final EditRevertService _editRevertService;
   final Logger _logger = Logger('BackgroundUploadService');
 
   final StreamController<TaskStatusUpdate> _taskStatusController = StreamController<TaskStatusUpdate>.broadcast();
@@ -205,9 +248,20 @@ class BackgroundUploadService {
   }
 
   void _handleTaskStatusUpdate(TaskStatusUpdate update) async {
+    UploadTaskMetadata? metadata;
+    if (update.task.metaData.isNotEmpty) {
+      try {
+        metadata = UploadTaskMetadata.fromJson(update.task.metaData);
+      } catch (_) {
+        metadata = null;
+      }
+    }
+
     switch (update.status) {
       case TaskStatus.complete:
-        unawaited(_handleLivePhoto(update));
+        unawaited(_handleLivePhoto(update, metadata));
+        unawaited(_handleEditPair(update, metadata));
+        unawaited(_recordPriorRemoteIdOnSuccess(update, metadata));
 
         if (CurrentPlatform.isIOS) {
           try {
@@ -220,19 +274,20 @@ class BackgroundUploadService {
 
         break;
 
+      case TaskStatus.failed:
+      case TaskStatus.canceled:
+      case TaskStatus.notFound:
+        unawaited(_cleanupTempResourceOnFailure(metadata));
+        break;
+
       default:
         break;
     }
   }
 
-  Future<void> _handleLivePhoto(TaskStatusUpdate update) async {
+  Future<void> _handleLivePhoto(TaskStatusUpdate update, UploadTaskMetadata? metadata) async {
     try {
-      if (update.task.metaData.isEmpty || update.task.metaData == '') {
-        return;
-      }
-
-      final metadata = UploadTaskMetadata.fromJson(update.task.metaData);
-      if (!metadata.isLivePhotos) {
+      if (metadata == null || !metadata.isLivePhotos) {
         return;
       }
 
@@ -258,6 +313,161 @@ class BackgroundUploadService {
     }
   }
 
+  /// When an edit-pair base upload completes, enqueue the edit upload stacked
+  /// onto it (stackParentId = the base's freshly-returned remote id).
+  Future<void> _handleEditPair(TaskStatusUpdate update, UploadTaskMetadata? metadata) async {
+    try {
+      if (metadata == null || !metadata.isEditPair) {
+        return;
+      }
+      if (metadata.basePath.isNotEmpty) {
+        try {
+          await File(metadata.basePath).delete();
+        } catch (_) {}
+      }
+      if (update.responseBody == null || update.responseBody!.isEmpty) {
+        return;
+      }
+      final baseRemoteId = jsonDecode(update.responseBody!)['id'] as String?;
+      if (baseRemoteId == null) {
+        return;
+      }
+      final localAsset = await _localAssetRepository.getById(metadata.localAssetId);
+      if (localAsset == null) {
+        return;
+      }
+      final editTask = await getEditUploadTask(localAsset, baseRemoteId);
+      if (editTask != null) {
+        await enqueueTasks([editTask]);
+      }
+    } catch (error, stackTrace) {
+      dPrint(() => "Error handling edit pair task: $error $stackTrace");
+    }
+  }
+
+  /// Records the uploaded remote id as the asset's priorRemoteId so a later
+  /// edit stacks onto it. Skipped for edit-pair base uploads — those become
+  /// stack members; the chained edit's success records the prior.
+  Future<void> _recordPriorRemoteIdOnSuccess(TaskStatusUpdate update, UploadTaskMetadata? metadata) async {
+    try {
+      if (metadata == null || metadata.isEditPair || metadata.localAssetId.isEmpty) {
+        return;
+      }
+      if (update.responseBody == null || update.responseBody!.isEmpty) {
+        return;
+      }
+      final remoteId = jsonDecode(update.responseBody!)['id'] as String?;
+      if (remoteId == null) {
+        return;
+      }
+      final localAsset = await _localAssetRepository.getById(metadata.localAssetId);
+      await _localAssetRepository.markSynced(
+        metadata.localAssetId,
+        priorRemoteId: remoteId,
+        syncedChecksum: localAsset?.checksum ?? '',
+      );
+    } catch (error, stackTrace) {
+      dPrint(() => "Error recording priorRemoteId: $error $stackTrace");
+    }
+  }
+
+  Future<void> _cleanupTempResourceOnFailure(UploadTaskMetadata? metadata) async {
+    if (metadata == null || metadata.basePath.isEmpty) {
+      return;
+    }
+    try {
+      await File(metadata.basePath).delete();
+    } catch (_) {}
+  }
+
+  /// Resolves how an iOS edit should stack: a [String] prior remote id to use
+  /// as stackParentId (absorption), a [BaseResource] whose bytes must upload as
+  /// a fresh base first, or null when there's no edit to handle.
+  Future<Object?> _tryGetBaseOrPrior(LocalAsset asset) async {
+    if (asset.priorRemoteId != null) {
+      return asset.priorRemoteId;
+    }
+    BaseResource? base;
+    try {
+      base = await _nativeSyncApi.getBaseResource(asset.id, allowNetworkAccess: true);
+    } catch (error, stack) {
+      _logger.warning(() => "Failed to read base resource for ${asset.id}", error, stack);
+      return null;
+    }
+    if (base == null) {
+      return null;
+    }
+    // Identical bytes (e.g. auto-HDR) — no real edit to stack.
+    if (base.sha1 == asset.checksum) {
+      try {
+        await File(base.path).delete();
+      } catch (_) {}
+      return null;
+    }
+    return base;
+  }
+
+  Future<UploadTask> _buildBaseUploadTask(LocalAsset asset, BaseResource base) async {
+    final metadata = UploadTaskMetadata(
+      localAssetId: asset.id,
+      isLivePhotos: false,
+      livePhotoVideoId: '',
+      isEditPair: true,
+      basePath: base.path,
+    ).toJson();
+
+    // The base is the unedited original (no adjustmentTime); the `_base`
+    // deviceAssetId keeps it distinct from the chained edit task.
+    return buildUploadTask(
+      File(base.path),
+      createdAt: asset.createdAt,
+      modifiedAt: asset.updatedAt,
+      originalFileName: p.setExtension(asset.name, p.extension(base.path)),
+      deviceAssetId: '${asset.id}_base',
+      metadata: metadata,
+      group: kBackupGroup,
+      isFavorite: asset.isFavorite,
+      requiresWiFi: _shouldRequireWiFi(asset),
+      cloudId: asset.cloudId,
+      latitude: asset.latitude?.toString(),
+      longitude: asset.longitude?.toString(),
+    );
+  }
+
+  @visibleForTesting
+  Future<UploadTask?> getEditUploadTask(LocalAsset asset, String stackParentId) async {
+    final entity = await _storageRepository.getAssetEntityForAsset(asset);
+    if (entity == null) {
+      return null;
+    }
+    final file = await _storageRepository.getFileForAsset(asset.id);
+    if (file == null) {
+      return null;
+    }
+
+    final fields = {'stackParentId': stackParentId};
+    final originalFileName = await _assetMediaRepository.getOriginalFilename(asset.id) ?? asset.name;
+    final metadata = UploadTaskMetadata(localAssetId: asset.id, isLivePhotos: false, livePhotoVideoId: '').toJson();
+
+    return buildUploadTask(
+      file,
+      createdAt: asset.createdAt,
+      modifiedAt: asset.updatedAt,
+      originalFileName: originalFileName,
+      deviceAssetId: asset.id,
+      metadata: metadata,
+      fields: fields,
+      group: kBackupEditPairGroup,
+      priority: 0,
+      isFavorite: asset.isFavorite,
+      requiresWiFi: _shouldRequireWiFi(asset),
+      cloudId: asset.cloudId,
+      adjustmentTime: asset.adjustmentTime?.toIso8601String(),
+      latitude: asset.latitude?.toString(),
+      longitude: asset.longitude?.toString(),
+    );
+  }
+
   @visibleForTesting
   Future<UploadTask?> getUploadTask(LocalAsset asset, {String group = kBackupGroup, int? priority}) async {
     final entity = await _storageRepository.getAssetEntityForAsset(asset);
@@ -266,6 +476,24 @@ class BackgroundUploadService {
       return null;
     }
 
+    // iOS edit pair: stack a user edit onto the original. Reuse a prior upload
+    // as the stack parent (absorption), or upload the unedited bytes as a fresh
+    // base first. Live-photo edits aren't handled.
+    if (!entity.isLivePhoto && CurrentPlatform.isIOS) {
+      // A reverted edit dedups against the existing stack base — flip the primary
+      // back and skip the upload entirely.
+      if (asset.priorRemoteId != null && await _editRevertService.tryDedupRevert(asset)) {
+        return null;
+      }
+      final pairResolution = await _tryGetBaseOrPrior(asset);
+      if (pairResolution is BaseResource) {
+        return _buildBaseUploadTask(asset, pairResolution);
+      }
+      if (pairResolution is String) {
+        return getEditUploadTask(asset, pairResolution);
+      }
+    }
+
     File? file;
 
     /// iOS LivePhoto has two files: a photo and a video.

mobile/lib/services/foreground_upload.service.dart

@@ -6,16 +6,21 @@ import 'package:hooks_riverpod/hooks_riverpod.dart';
 import 'package:immich_mobile/domain/models/asset/asset_metadata.model.dart';
 import 'package:immich_mobile/domain/models/asset/base_asset.model.dart';
 import 'package:immich_mobile/domain/models/store.model.dart';
+import 'package:immich_mobile/domain/services/edit_revert.service.dart';
 import 'package:immich_mobile/entities/store.entity.dart';
 import 'package:immich_mobile/extensions/network_capability_extensions.dart';
 import 'package:immich_mobile/extensions/platform_extensions.dart';
 import 'package:immich_mobile/extensions/translate_extensions.dart';
 import 'package:immich_mobile/infrastructure/repositories/backup.repository.dart';
+import 'package:immich_mobile/infrastructure/repositories/local_asset.repository.dart';
 import 'package:immich_mobile/infrastructure/repositories/metadata.repository.dart';
 import 'package:immich_mobile/infrastructure/repositories/storage.repository.dart';
 import 'package:immich_mobile/platform/connectivity_api.g.dart';
+import 'package:immich_mobile/platform/native_sync_api.g.dart';
+import 'package:immich_mobile/providers/infrastructure/asset.provider.dart';
 import 'package:immich_mobile/providers/infrastructure/platform.provider.dart';
 import 'package:immich_mobile/providers/infrastructure/storage.provider.dart';
+import 'package:immich_mobile/providers/infrastructure/sync.provider.dart';
 import 'package:immich_mobile/repositories/asset_media.repository.dart';
 import 'package:immich_mobile/repositories/upload.repository.dart';
 import 'package:logging/logging.dart';
@@ -39,6 +44,9 @@ final foregroundUploadServiceProvider = Provider((ref) {
     ref.watch(backupRepositoryProvider),
     ref.watch(connectivityApiProvider),
     ref.watch(assetMediaRepositoryProvider),
+    ref.watch(nativeSyncApiProvider),
+    ref.watch(localAssetRepository),
+    ref.watch(editRevertServiceProvider),
   );
 });
 
@@ -54,6 +62,9 @@ class ForegroundUploadService {
     this._backupRepository,
     this._connectivityApi,
     this._assetMediaRepository,
+    this._nativeSyncApi,
+    this._localAssetRepository,
+    this._editRevertService,
   );
 
   final UploadRepository _uploadRepository;
@@ -61,6 +72,9 @@ class ForegroundUploadService {
   final DriftBackupRepository _backupRepository;
   final ConnectivityApi _connectivityApi;
   final AssetMediaRepository _assetMediaRepository;
+  final NativeSyncApi _nativeSyncApi;
+  final DriftLocalAssetRepository _localAssetRepository;
+  final EditRevertService _editRevertService;
   final Logger _logger = Logger('ForegroundUploadService');
 
   bool shouldAbortUpload = false;
@@ -250,6 +264,13 @@ class ForegroundUploadService {
         return;
       }
 
+      // A reverted iOS edit dedups against the existing stack base instead of
+      // re-uploading; tryDedupRevert flips the primary back and skips the upload.
+      if (Platform.isIOS && asset.priorRemoteId != null && await _editRevertService.tryDedupRevert(asset)) {
+        callbacks.onSuccess?.call(asset.localId!, asset.priorRemoteId!);
+        return;
+      }
+
       final isAvailableLocally = await _storageRepository.isAssetAvailableLocally(asset.id);
 
       if (!isAvailableLocally && CurrentPlatform.isIOS) {
@@ -371,6 +392,11 @@ class ForegroundUploadService {
         ]);
       }
 
+      final stackParentId = await _maybeUploadBaseResource(asset, Map.of(fields), cancelToken);
+      if (stackParentId != null) {
+        fields['stackParentId'] = stackParentId;
+      }
+
       final onProgress = callbacks.onProgress;
       final result = await _uploadRepository.uploadFile(
         file: file,
@@ -384,6 +410,13 @@ class ForegroundUploadService {
       );
 
       if (result.isSuccess && result.remoteAssetId != null) {
+        unawaited(
+          _localAssetRepository.markSynced(
+            asset.localId!,
+            priorRemoteId: result.remoteAssetId!,
+            syncedChecksum: asset.checksum ?? '',
+          ),
+        );
         callbacks.onSuccess?.call(asset.localId!, result.remoteAssetId!);
       } else if (result.isCancelled) {
         _logger.warning(() => "Backup was cancelled by the user");
@@ -415,6 +448,60 @@ class ForegroundUploadService {
     }
   }
 
+  /// For an edited iOS photo, uploads the original camera bytes and returns its
+  /// remote id to use as the edit's stackParentId. Returns null for non-edits.
+  Future<String?> _maybeUploadBaseResource(
+    LocalAsset asset,
+    Map<String, String> baseFields,
+    Completer<void>? cancelToken,
+  ) async {
+    if (!Platform.isIOS) {
+      return null;
+    }
+
+    // A prior upload exists, so stack the new edit onto it instead of creating a
+    // duplicate top-level asset.
+    if (asset.priorRemoteId != null) {
+      return asset.priorRemoteId;
+    }
+
+    BaseResource? base;
+    try {
+      base = await _nativeSyncApi.getBaseResource(asset.id, allowNetworkAccess: true);
+    } catch (error, stack) {
+      _logger.warning(() => "Failed to read base resource for ${asset.id}", error, stack);
+      return null;
+    }
+    if (base == null) {
+      return null;
+    }
+
+    final baseFile = File(base.path);
+    // Identical bytes (e.g. auto-HDR) — no real edit to stack.
+    if (base.sha1 == asset.checksum) {
+      try {
+        await baseFile.delete();
+      } catch (_) {}
+      return null;
+    }
+
+    try {
+      final baseName = p.setExtension(asset.name, p.extension(base.path));
+      final result = await _uploadRepository.uploadFile(
+        file: baseFile,
+        originalFileName: baseName,
+        fields: baseFields,
+        cancelToken: cancelToken,
+        logContext: 'baseResource[${asset.localId}]',
+      );
+      return result.isSuccess ? result.remoteAssetId : null;
+    } finally {
+      try {
+        await baseFile.delete();
+      } catch (_) {}
+    }
+  }
+
   Future<UploadResult> _uploadSingleFile(
     File file, {
     required String deviceAssetId,

mobile/openapi/lib/api/assets_api.dart

@@ -1252,8 +1252,11 @@ class AssetsApi {
   /// * [MultipartFile] sidecarData:
   ///   Sidecar file data
   ///
+  /// * [String] stackParentId:
+  ///   Stack this asset onto the parent asset, with the new asset as the stack primary
+  ///
   /// * [AssetVisibility] visibility:
-  Future<Response> uploadAssetWithHttpInfo(MultipartFile assetData, DateTime fileCreatedAt, DateTime fileModifiedAt, { String? key, String? slug, String? xImmichChecksum, int? duration, String? filename, bool? isFavorite, String? livePhotoVideoId, List<AssetMetadataUpsertItemDto>? metadata, MultipartFile? sidecarData, AssetVisibility? visibility, }) async {
+  Future<Response> uploadAssetWithHttpInfo(MultipartFile assetData, DateTime fileCreatedAt, DateTime fileModifiedAt, { String? key, String? slug, String? xImmichChecksum, int? duration, String? filename, bool? isFavorite, String? livePhotoVideoId, List<AssetMetadataUpsertItemDto>? metadata, MultipartFile? sidecarData, String? stackParentId, AssetVisibility? visibility, }) async {
     // ignore: prefer_const_declarations
     final apiPath = r'/assets';
 
@@ -1317,6 +1320,10 @@ class AssetsApi {
       mp.fields[r'sidecarData'] = sidecarData.field;
       mp.files.add(sidecarData);
     }
+    if (stackParentId != null) {
+      hasFields = true;
+      mp.fields[r'stackParentId'] = parameterToString(stackParentId);
+    }
     if (visibility != null) {
       hasFields = true;
       mp.fields[r'visibility'] = parameterToString(visibility);
@@ -1376,9 +1383,12 @@ class AssetsApi {
   /// * [MultipartFile] sidecarData:
   ///   Sidecar file data
   ///
+  /// * [String] stackParentId:
+  ///   Stack this asset onto the parent asset, with the new asset as the stack primary
+  ///
   /// * [AssetVisibility] visibility:
-  Future<AssetMediaResponseDto?> uploadAsset(MultipartFile assetData, DateTime fileCreatedAt, DateTime fileModifiedAt, { String? key, String? slug, String? xImmichChecksum, int? duration, String? filename, bool? isFavorite, String? livePhotoVideoId, List<AssetMetadataUpsertItemDto>? metadata, MultipartFile? sidecarData, AssetVisibility? visibility, }) async {
-    final response = await uploadAssetWithHttpInfo(assetData, fileCreatedAt, fileModifiedAt,  key: key, slug: slug, xImmichChecksum: xImmichChecksum, duration: duration, filename: filename, isFavorite: isFavorite, livePhotoVideoId: livePhotoVideoId, metadata: metadata, sidecarData: sidecarData, visibility: visibility, );
+  Future<AssetMediaResponseDto?> uploadAsset(MultipartFile assetData, DateTime fileCreatedAt, DateTime fileModifiedAt, { String? key, String? slug, String? xImmichChecksum, int? duration, String? filename, bool? isFavorite, String? livePhotoVideoId, List<AssetMetadataUpsertItemDto>? metadata, MultipartFile? sidecarData, String? stackParentId, AssetVisibility? visibility, }) async {
+    final response = await uploadAssetWithHttpInfo(assetData, fileCreatedAt, fileModifiedAt,  key: key, slug: slug, xImmichChecksum: xImmichChecksum, duration: duration, filename: filename, isFavorite: isFavorite, livePhotoVideoId: livePhotoVideoId, metadata: metadata, sidecarData: sidecarData, stackParentId: stackParentId, visibility: visibility, );
     if (response.statusCode >= HttpStatus.badRequest) {
       throw ApiException(response.statusCode, await _decodeBodyBytes(response));
     }

mobile/pigeon/native_sync_api.dart

@@ -110,6 +110,21 @@ class CloudIdResult {
   const CloudIdResult({required this.assetId, this.error, this.cloudId});
 }
 
+class BaseResource {
+  final String path;
+  final String sha1;
+  final int sizeBytes;
+  final String mimeType;
+
+  const BaseResource({required this.path, required this.sha1, required this.sizeBytes, required this.mimeType});
+}
+
+// Whether an iOS asset currently carries a user edit, as opposed to a
+// capture-time Photographic Style or a reverted edit. `unknown` means the
+// adjustment data couldn't be read (e.g. the asset is offloaded to iCloud and
+// network wasn't allowed), so callers must not treat it as "not edited".
+enum EditState { notEdited, edited, unknown }
+
 @HostApi()
 abstract class NativeSyncApi {
   bool shouldFullSync();
@@ -144,4 +159,12 @@ abstract class NativeSyncApi {
 
   @TaskQueue(type: TaskQueueType.serialBackgroundThread)
   List<CloudIdResult> getCloudIdForAssetIds(List<String> assetIds);
+
+  @async
+  @TaskQueue(type: TaskQueueType.serialBackgroundThread)
+  BaseResource? getBaseResource(String assetId, {bool allowNetworkAccess = false});
+
+  @async
+  @TaskQueue(type: TaskQueueType.serialBackgroundThread)
+  EditState getEditState(String assetId, {bool allowNetworkAccess = false});
 }

mobile/test/domain/service.mock.dart

@@ -1,3 +1,4 @@
+import 'package:immich_mobile/domain/services/edit_revert.service.dart';
 import 'package:immich_mobile/domain/services/store.service.dart';
 import 'package:immich_mobile/domain/utils/background_sync.dart';
 import 'package:immich_mobile/platform/native_sync_api.g.dart';
@@ -11,3 +12,5 @@ class MockBackgroundSyncManager extends Mock implements BackgroundSyncManager {}
 class MockNativeSyncApi extends Mock implements NativeSyncApi {}
 
 class MockAppSettingsService extends Mock implements AppSettingsService {}
+
+class MockEditRevertService extends Mock implements EditRevertService {}

mobile/test/drift/main/generated/schema.dart

@@ -30,6 +30,8 @@ import 'schema_v23.dart' as v23;
 import 'schema_v24.dart' as v24;
 import 'schema_v25.dart' as v25;
 import 'schema_v26.dart' as v26;
+import 'schema_v27.dart' as v27;
+import 'schema_v28.dart' as v28;
 
 class GeneratedHelper implements SchemaInstantiationHelper {
   @override
@@ -87,6 +89,10 @@ class GeneratedHelper implements SchemaInstantiationHelper {
         return v25.DatabaseAtV25(db);
       case 26:
         return v26.DatabaseAtV26(db);
+      case 27:
+        return v27.DatabaseAtV27(db);
+      case 28:
+        return v28.DatabaseAtV28(db);
       default:
         throw MissingSchemaException(version, versions);
     }
@@ -119,5 +125,7 @@ class GeneratedHelper implements SchemaInstantiationHelper {
     24,
     25,
     26,
+    27,
+    28,
   ];
 }

mobile/test/infrastructure/repository.mock.dart

@@ -5,6 +5,7 @@ import 'package:immich_mobile/infrastructure/repositories/log.repository.dart';
 import 'package:immich_mobile/infrastructure/repositories/metadata.repository.dart';
 import 'package:immich_mobile/infrastructure/repositories/remote_album.repository.dart';
 import 'package:immich_mobile/infrastructure/repositories/remote_asset.repository.dart';
+import 'package:immich_mobile/infrastructure/repositories/stack.repository.dart';
 import 'package:immich_mobile/infrastructure/repositories/storage.repository.dart';
 import 'package:immich_mobile/infrastructure/repositories/store.repository.dart';
 import 'package:immich_mobile/infrastructure/repositories/sync_api.repository.dart';
@@ -36,6 +37,8 @@ class MockRemoteAssetRepository extends Mock implements RemoteAssetRepository {}
 
 class MockTrashedLocalAssetRepository extends Mock implements DriftTrashedLocalAssetRepository {}
 
+class MockDriftStackRepository extends Mock implements DriftStackRepository {}
+
 class MockStorageRepository extends Mock implements StorageRepository {}
 
 class MockDriftBackupRepository extends Mock implements DriftBackupRepository {}

mobile/test/services/background_upload.service_test.dart

@@ -6,6 +6,7 @@ import 'package:drift/native.dart';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_test/flutter_test.dart';
+import 'package:immich_mobile/constants/constants.dart';
 import 'package:immich_mobile/domain/models/asset/base_asset.model.dart';
 import 'package:immich_mobile/domain/models/store.model.dart';
 import 'package:immich_mobile/domain/services/store.service.dart';
@@ -13,9 +14,11 @@ import 'package:immich_mobile/entities/store.entity.dart';
 import 'package:immich_mobile/infrastructure/repositories/db.repository.dart';
 import 'package:immich_mobile/infrastructure/repositories/metadata.repository.dart';
 import 'package:immich_mobile/infrastructure/repositories/store.repository.dart';
+import 'package:immich_mobile/platform/native_sync_api.g.dart';
 import 'package:immich_mobile/services/background_upload.service.dart';
 import 'package:mocktail/mocktail.dart';
 
+import '../domain/service.mock.dart';
 import '../fixtures/asset.stub.dart';
 import '../infrastructure/repository.mock.dart';
 import '../mocks/asset_entity.mock.dart';
@@ -28,10 +31,13 @@ void main() {
   late MockDriftLocalAssetRepository mockLocalAssetRepository;
   late MockDriftBackupRepository mockBackupRepository;
   late MockAssetMediaRepository mockAssetMediaRepository;
+  late MockNativeSyncApi mockNativeSyncApi;
+  late MockEditRevertService mockEditRevertService;
   late Drift db;
 
   setUpAll(() async {
     TestWidgetsFlutterBinding.ensureInitialized();
+    registerFallbackValue(LocalAssetStub.image1);
     TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger.setMockMethodCallHandler(
       const MethodChannel('plugins.flutter.io/path_provider'),
       (MethodCall methodCall) async => 'test',
@@ -50,6 +56,8 @@ void main() {
     mockLocalAssetRepository = MockDriftLocalAssetRepository();
     mockBackupRepository = MockDriftBackupRepository();
     mockAssetMediaRepository = MockAssetMediaRepository();
+    mockNativeSyncApi = MockNativeSyncApi();
+    mockEditRevertService = MockEditRevertService();
 
     sut = BackgroundUploadService(
       mockUploadRepository,
@@ -57,8 +65,18 @@ void main() {
       mockLocalAssetRepository,
       mockBackupRepository,
       mockAssetMediaRepository,
+      mockNativeSyncApi,
+      mockEditRevertService,
     );
 
+    // Default: no edit base, so getUploadTask falls through to the normal path.
+    when(
+      () => mockNativeSyncApi.getBaseResource(any(), allowNetworkAccess: any(named: 'allowNetworkAccess')),
+    ).thenAnswer((_) async => null);
+
+    // Default: not a revert, so getUploadTask proceeds with the normal flow.
+    when(() => mockEditRevertService.tryDedupRevert(any())).thenAnswer((_) async => false);
+
     mockUploadRepository.onUploadStatus = (_) {};
     mockUploadRepository.onTaskProgress = (_) {};
   });
@@ -122,6 +140,71 @@ void main() {
     });
   });
 
+  group('getUploadTask edit pair', () {
+    test('absorption: stacks the edit under the prior upload via stackParentId', () async {
+      debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
+      addTearDown(() => debugDefaultTargetPlatformOverride = null);
+
+      final asset = LocalAssetStub.image1.copyWith(priorRemoteId: 'prior-remote-1');
+      final mockEntity = MockAssetEntity();
+      when(() => mockEntity.isLivePhoto).thenReturn(false);
+      when(() => mockStorageRepository.getAssetEntityForAsset(asset)).thenAnswer((_) async => mockEntity);
+      when(() => mockStorageRepository.getFileForAsset(asset.id)).thenAnswer((_) async => File('/path/to/edit.jpg'));
+      when(() => mockAssetMediaRepository.getOriginalFilename(asset.id)).thenAnswer((_) async => 'edit.jpg');
+
+      final task = await sut.getUploadTask(asset);
+
+      expect(task, isNotNull);
+      expect(task!.group, kBackupEditPairGroup);
+      expect(task.fields['stackParentId'], 'prior-remote-1');
+      verifyNever(() => mockNativeSyncApi.getBaseResource(any(), allowNetworkAccess: any(named: 'allowNetworkAccess')));
+    });
+
+    test('builds a base upload task for an unsynced edit', () async {
+      debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
+      addTearDown(() => debugDefaultTargetPlatformOverride = null);
+
+      final asset = LocalAssetStub.image1.copyWith(checksum: 'edited-sha1');
+      final mockEntity = MockAssetEntity();
+      when(() => mockEntity.isLivePhoto).thenReturn(false);
+      when(() => mockStorageRepository.getAssetEntityForAsset(asset)).thenAnswer((_) async => mockEntity);
+      when(
+        () => mockNativeSyncApi.getBaseResource(asset.id, allowNetworkAccess: any(named: 'allowNetworkAccess')),
+      ).thenAnswer(
+        (_) async => BaseResource(path: '/tmp/base.jpg', sha1: 'original-sha1', sizeBytes: 100, mimeType: 'image/jpeg'),
+      );
+
+      final task = await sut.getUploadTask(asset);
+
+      expect(task, isNotNull);
+      expect(task!.group, kBackupGroup);
+      expect(task.metaData, contains('"isEditPair":true'));
+    });
+
+    test('falls through to a normal upload when base bytes match the checksum', () async {
+      debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
+      addTearDown(() => debugDefaultTargetPlatformOverride = null);
+
+      final asset = LocalAssetStub.image1.copyWith(checksum: 'same-sha1');
+      final mockEntity = MockAssetEntity();
+      when(() => mockEntity.isLivePhoto).thenReturn(false);
+      when(() => mockStorageRepository.getAssetEntityForAsset(asset)).thenAnswer((_) async => mockEntity);
+      when(() => mockStorageRepository.getFileForAsset(asset.id)).thenAnswer((_) async => File('/path/to/file.jpg'));
+      when(() => mockAssetMediaRepository.getOriginalFilename(asset.id)).thenAnswer((_) async => 'photo.jpg');
+      when(
+        () => mockNativeSyncApi.getBaseResource(asset.id, allowNetworkAccess: any(named: 'allowNetworkAccess')),
+      ).thenAnswer(
+        (_) async => BaseResource(path: '/tmp/base.jpg', sha1: 'same-sha1', sizeBytes: 100, mimeType: 'image/jpeg'),
+      );
+
+      final task = await sut.getUploadTask(asset);
+
+      expect(task, isNotNull);
+      expect(task!.group, kBackupGroup);
+      expect(task.fields.containsKey('stackParentId'), isFalse);
+    });
+  });
+
   group('getLivePhotoUploadTask', () {
     test('should call getOriginalFilename for live photo upload task', () async {
       final asset = LocalAssetStub.image1;
@@ -172,6 +255,8 @@ void main() {
         mockLocalAssetRepository,
         mockBackupRepository,
         mockAssetMediaRepository,
+        mockNativeSyncApi,
+        mockEditRevertService,
       );
       addTearDown(() => sutWithV24.dispose());
 
@@ -222,6 +307,8 @@ void main() {
         mockLocalAssetRepository,
         mockBackupRepository,
         mockAssetMediaRepository,
+        mockNativeSyncApi,
+        mockEditRevertService,
       );
       addTearDown(() => sutAndroid.dispose());
 
@@ -262,6 +349,8 @@ void main() {
         mockLocalAssetRepository,
         mockBackupRepository,
         mockAssetMediaRepository,
+        mockNativeSyncApi,
+        mockEditRevertService,
       );
       addTearDown(() => sutWithV24.dispose());
 
@@ -302,6 +391,8 @@ void main() {
         mockLocalAssetRepository,
         mockBackupRepository,
         mockAssetMediaRepository,
+        mockNativeSyncApi,
+        mockEditRevertService,
       );
       addTearDown(() => sutWithV24.dispose());
 

mobile/test/unit/mocks.dart

@@ -4,11 +4,15 @@ import 'package:mocktail/mocktail.dart' as mocktail;
 
 import '../domain/service.mock.dart';
 import '../infrastructure/repository.mock.dart';
+import '../repository.mocks.dart';
 
 class UnitMocks {
   final localAlbum = MockLocalAlbumRepository();
   final localAsset = MockDriftLocalAssetRepository();
   final trashedAsset = MockTrashedLocalAssetRepository();
+  final stack = MockDriftStackRepository();
+  final assetApi = MockAssetApiRepository();
+  final editRevert = MockEditRevertService();
 
   final nativeApi = MockNativeSyncApi();
 
@@ -31,6 +35,9 @@ class UnitMocks {
     mocktail.reset(localAlbum);
     mocktail.reset(localAsset);
     mocktail.reset(trashedAsset);
+    mocktail.reset(stack);
+    mocktail.reset(assetApi);
+    mocktail.reset(editRevert);
     mocktail.reset(nativeApi);
   }
 }

mobile/test/unit/services/edit_revert_service_test.dart

@@ -0,0 +1,121 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:immich_mobile/domain/models/asset/base_asset.model.dart';
+import 'package:immich_mobile/domain/services/edit_revert.service.dart';
+import 'package:immich_mobile/platform/native_sync_api.g.dart';
+import 'package:mocktail/mocktail.dart';
+
+import '../mocks.dart';
+
+void main() {
+  late EditRevertService sut;
+  final mocks = UnitMocks();
+
+  LocalAsset asset({String? priorRemoteId, String? checksum = 'reverted-sha1'}) => LocalAsset(
+    id: 'local-1',
+    name: 'photo.jpg',
+    type: AssetType.image,
+    createdAt: DateTime(2025),
+    updatedAt: DateTime(2025, 2),
+    playbackStyle: AssetPlaybackStyle.image,
+    isEdited: false,
+    priorRemoteId: priorRemoteId,
+    checksum: checksum,
+  );
+
+  setUp(() {
+    sut = EditRevertService(
+      nativeSyncApi: mocks.nativeApi,
+      stackRepository: mocks.stack,
+      localAssetRepository: mocks.localAsset,
+      assetApiRepository: mocks.assetApi,
+    );
+  });
+
+  tearDown(() {
+    mocks.reset();
+  });
+
+  group('tryDedupRevert', () {
+    test('returns false when the asset was never uploaded as an edit', () async {
+      expect(await sut.tryDedupRevert(asset(priorRemoteId: null)), isFalse);
+      verifyNever(() => mocks.nativeApi.getEditState(any(), allowNetworkAccess: any(named: 'allowNetworkAccess')));
+    });
+
+    test('returns false (lets the pair flow run) when there is still a live edit', () async {
+      when(
+        () => mocks.nativeApi.getEditState('local-1', allowNetworkAccess: any(named: 'allowNetworkAccess')),
+      ).thenAnswer((_) async => EditState.edited);
+
+      expect(await sut.tryDedupRevert(asset(priorRemoteId: 'remote-edit')), isFalse);
+      verifyNever(() => mocks.stack.findStackIdByRemoteId(any()));
+    });
+
+    test('returns false when the edit state cannot be read (offloaded to iCloud)', () async {
+      when(
+        () => mocks.nativeApi.getEditState('local-1', allowNetworkAccess: any(named: 'allowNetworkAccess')),
+      ).thenAnswer((_) async => EditState.unknown);
+
+      expect(await sut.tryDedupRevert(asset(priorRemoteId: 'remote-edit')), isFalse);
+      verifyNever(() => mocks.stack.findStackIdByRemoteId(any()));
+    });
+
+    test('returns false when the prior remote is not in a stack', () async {
+      when(
+        () => mocks.nativeApi.getEditState('local-1', allowNetworkAccess: any(named: 'allowNetworkAccess')),
+      ).thenAnswer((_) async => EditState.notEdited);
+      when(() => mocks.stack.findStackIdByRemoteId('remote-edit')).thenAnswer((_) async => null);
+
+      expect(await sut.tryDedupRevert(asset(priorRemoteId: 'remote-edit')), isFalse);
+      verifyNever(() => mocks.assetApi.setStackPrimary(any(), any()));
+    });
+
+    test('returns false when the stack has no base member to flip back to', () async {
+      when(
+        () => mocks.nativeApi.getEditState('local-1', allowNetworkAccess: any(named: 'allowNetworkAccess')),
+      ).thenAnswer((_) async => EditState.notEdited);
+      when(() => mocks.stack.findStackIdByRemoteId('remote-edit')).thenAnswer((_) async => 'stack-1');
+      when(() => mocks.stack.findStackBaseId('stack-1', excludeId: 'remote-edit')).thenAnswer((_) async => null);
+
+      expect(await sut.tryDedupRevert(asset(priorRemoteId: 'remote-edit')), isFalse);
+      verifyNever(() => mocks.assetApi.setStackPrimary(any(), any()));
+    });
+
+    test('flips the primary back to the base via prior_remote_id and trashes the edit', () async {
+      when(
+        () => mocks.nativeApi.getEditState('local-1', allowNetworkAccess: any(named: 'allowNetworkAccess')),
+      ).thenAnswer((_) async => EditState.notEdited);
+      when(() => mocks.stack.findStackIdByRemoteId('remote-edit')).thenAnswer((_) async => 'stack-1');
+      when(
+        () => mocks.stack.findStackBaseId('stack-1', excludeId: 'remote-edit'),
+      ).thenAnswer((_) async => 'remote-base');
+      when(() => mocks.assetApi.setStackPrimary('stack-1', 'remote-base')).thenAnswer((_) async {});
+      when(() => mocks.stack.setPrimary('stack-1', 'remote-base')).thenAnswer((_) async {});
+      when(
+        () => mocks.localAsset.markSynced(
+          'local-1',
+          priorRemoteId: 'remote-base',
+          syncedChecksum: any(named: 'syncedChecksum'),
+        ),
+      ).thenAnswer((_) async {});
+      when(() => mocks.stack.getOtherMemberIds('stack-1', 'remote-base')).thenAnswer((_) async => ['remote-edit']);
+      when(() => mocks.assetApi.delete(['remote-edit'], false)).thenAnswer((_) async {});
+      when(() => mocks.assetApi.unStack(['stack-1'])).thenAnswer((_) async {});
+      when(() => mocks.stack.applyRevertCleanup('stack-1', ['remote-edit'])).thenAnswer((_) async {});
+
+      expect(await sut.tryDedupRevert(asset(priorRemoteId: 'remote-edit')), isTrue);
+
+      verify(() => mocks.assetApi.setStackPrimary('stack-1', 'remote-base')).called(1);
+      verify(() => mocks.stack.setPrimary('stack-1', 'remote-base')).called(1);
+      verify(
+        () => mocks.localAsset.markSynced(
+          'local-1',
+          priorRemoteId: 'remote-base',
+          syncedChecksum: any(named: 'syncedChecksum'),
+        ),
+      ).called(1);
+      verify(() => mocks.assetApi.delete(['remote-edit'], false)).called(1);
+      verify(() => mocks.assetApi.unStack(['stack-1'])).called(1);
+      verify(() => mocks.stack.applyRevertCleanup('stack-1', ['remote-edit'])).called(1);
+    });
+  });
+}

mobile/test/unit/services/hash_service_test.dart

@@ -18,6 +18,9 @@ void main() {
       localAssetRepository: mocks.localAsset,
       nativeSyncApi: mocks.nativeApi,
       trashedLocalAssetRepository: mocks.trashedAsset,
+      stackRepository: mocks.stack,
+      assetApiRepository: mocks.assetApi,
+      editRevertService: mocks.editRevert,
     );
 
     when(() => mocks.localAsset.reconcileHashesFromCloudId()).thenAnswer((_) async => {});
@@ -110,6 +113,9 @@ void main() {
           nativeSyncApi: mocks.nativeApi,
           batchSize: batchSize,
           trashedLocalAssetRepository: mocks.trashedAsset,
+          stackRepository: mocks.stack,
+          assetApiRepository: mocks.assetApi,
+          editRevertService: mocks.editRevert,
         );
 
         final album = LocalAlbumFactory.create();

open-api/immich-openapi-specs.json

@@ -16490,6 +16490,12 @@
             "format": "binary",
             "type": "string"
           },
+          "stackParentId": {
+            "description": "Stack this asset onto the parent asset, with the new asset as the stack primary",
+            "format": "uuid",
+            "pattern": "^([0-9a-fA-F]{8}-[0-9a-fA-F]{4}-4[0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12})$",
+            "type": "string"
+          },
           "visibility": {
             "$ref": "#/components/schemas/AssetVisibility"
           }

packages/sdk/src/fetch-client.ts

@@ -630,6 +630,8 @@ export type AssetMediaCreateDto = {
     metadata?: AssetMetadataUpsertItemDto[];
     /** Sidecar file data */
     sidecarData?: Blob;
+    /** Stack this asset onto the parent asset, with the new asset as the stack primary */
+    stackParentId?: string;
     visibility?: AssetVisibility;
 };
 export type AssetMediaResponseDto = {

server/src/dtos/asset-media.dto.ts

@@ -48,6 +48,10 @@ const AssetMediaCreateSchema = AssetMediaBaseSchema.extend({
   isFavorite: stringToBool.optional().describe('Mark as favorite'),
   visibility: AssetVisibilitySchema.optional(),
   livePhotoVideoId: z.uuidv4().optional().describe('Live photo video ID'),
+  stackParentId: z
+    .uuidv4()
+    .optional()
+    .describe('Stack this asset onto the parent asset, with the new asset as the stack primary'),
   metadata: JsonParsed.pipe(z.array(AssetMetadataUpsertItemSchema)).optional().describe('Asset metadata items'),
   [UploadFieldName.SIDECAR_DATA]: z
     .any()

server/src/repositories/stack.repository.ts

@@ -6,7 +6,7 @@ import { columns } from 'src/database';
 import { DummyValue, GenerateSql } from 'src/decorators';
 import { DB } from 'src/schema';
 import { StackTable } from 'src/schema/tables/stack.table';
-import { asUuid, withDefaultVisibility } from 'src/utils/database';
+import { asUuid, isStackPrimaryConstraint, withDefaultVisibility } from 'src/utils/database';
 
 export interface StackSearch {
   ownerId: string;
@@ -124,6 +124,63 @@ export class StackRepository {
     });
   }
 
+  async linkAsset(
+    ownerId: string,
+    newAssetId: string,
+    parentId: string,
+  ): Promise<{ stackId: string; created: boolean } | null> {
+    try {
+      return await this.db.transaction().execute(async (tx) => {
+        // Lock the parent so two concurrent uploads can't each create a stack for it.
+        const parent = await tx
+          .selectFrom('asset')
+          .select(['id', 'ownerId', 'stackId', 'deletedAt'])
+          .where('id', '=', asUuid(parentId))
+          .forUpdate()
+          .executeTakeFirst();
+
+        if (!parent || parent.ownerId !== ownerId || parent.deletedAt) {
+          return null;
+        }
+
+        if (parent.stackId) {
+          await tx
+            .updateTable('asset')
+            .set({ stackId: parent.stackId, updatedAt: new Date() })
+            .where('id', '=', asUuid(newAssetId))
+            .execute();
+          await tx
+            .updateTable('stack')
+            .set({ primaryAssetId: newAssetId, updatedAt: new Date() })
+            .where('id', '=', parent.stackId)
+            .execute();
+          return { stackId: parent.stackId, created: false };
+        }
+
+        const stack = await tx
+          .insertInto('stack')
+          .values({ ownerId, primaryAssetId: newAssetId })
+          .returning('id')
+          .executeTakeFirstOrThrow();
+
+        await tx
+          .updateTable('asset')
+          .set({ stackId: stack.id, updatedAt: new Date() })
+          .where('id', 'in', [asUuid(newAssetId), parent.id])
+          .execute();
+
+        return { stackId: stack.id, created: true };
+      });
+    } catch (error) {
+      // newAssetId may already be another stack's primary (e.g. a retried upload) —
+      // treat the unique-constraint hit as "couldn't stack" rather than a 500.
+      if (isStackPrimaryConstraint(error)) {
+        return null;
+      }
+      throw error;
+    }
+  }
+
   @GenerateSql({ params: [DummyValue.UUID] })
   async delete(id: string): Promise<void> {
     await this.db.deleteFrom('stack').where('id', '=', asUuid(id)).execute();

server/src/services/asset-media.service.spec.ts

@@ -418,6 +418,79 @@ describe(AssetMediaService.name, () => {
       expect(mocks.asset.update).not.toHaveBeenCalled();
     });
 
+    it('should stack a new asset onto the parent and emit the populated stackId', async () => {
+      const file = {
+        uuid: 'random-uuid',
+        originalPath: 'fake_path/asset_1.jpeg',
+        mimeType: 'image/jpeg',
+        checksum: Buffer.from('file hash', 'utf8'),
+        originalName: 'asset_1.jpeg',
+        size: 42,
+      };
+      const parent = AssetFactory.create();
+      mocks.access.asset.checkOwnerAccess.mockResolvedValue(new Set([parent.id]));
+      mocks.asset.getById.mockResolvedValueOnce(getForAsset(parent));
+      mocks.asset.create.mockResolvedValue(assetEntity);
+      mocks.stack.linkAsset.mockResolvedValue({ stackId: 'stack-1', created: true });
+
+      await expect(sut.uploadAsset(authStub.user1, { ...createDto, stackParentId: parent.id }, file)).resolves.toEqual({
+        id: 'id_1',
+        status: AssetMediaStatus.CREATED,
+      });
+
+      expect(mocks.stack.linkAsset).toHaveBeenCalledWith(authStub.user1.user.id, assetEntity.id, parent.id);
+      expect(mocks.event.emit).toHaveBeenCalledWith('AssetCreate', {
+        asset: expect.objectContaining({ stackId: 'stack-1' }),
+      });
+    });
+
+    it('should reject stacking onto a trashed asset', async () => {
+      const file = {
+        uuid: 'random-uuid',
+        originalPath: 'fake_path/asset_1.jpeg',
+        mimeType: 'image/jpeg',
+        checksum: Buffer.from('file hash', 'utf8'),
+        originalName: 'asset_1.jpeg',
+        size: 42,
+      };
+      const parent = AssetFactory.create();
+      mocks.access.asset.checkOwnerAccess.mockResolvedValue(new Set([parent.id]));
+      mocks.asset.getById.mockResolvedValueOnce({ ...getForAsset(parent), deletedAt: new Date() });
+
+      await expect(
+        sut.uploadAsset(authStub.user1, { ...createDto, stackParentId: parent.id }, file),
+      ).rejects.toBeInstanceOf(BadRequestException);
+
+      expect(mocks.asset.create).not.toHaveBeenCalled();
+      expect(mocks.stack.linkAsset).not.toHaveBeenCalled();
+    });
+
+    it('should adopt a duplicate into the stack when stacking', async () => {
+      const file = {
+        uuid: 'random-uuid',
+        originalPath: 'fake_path/asset_1.jpeg',
+        mimeType: 'image/jpeg',
+        checksum: Buffer.from('file hash', 'utf8'),
+        originalName: 'asset_1.jpeg',
+        size: 0,
+      };
+      const parent = AssetFactory.create();
+      const error = new Error('unique key violation');
+      (error as any).constraint_name = ASSET_CHECKSUM_CONSTRAINT;
+      mocks.access.asset.checkOwnerAccess.mockResolvedValue(new Set([parent.id]));
+      mocks.asset.getById.mockResolvedValueOnce(getForAsset(parent));
+      mocks.asset.create.mockRejectedValue(error);
+      mocks.asset.getUploadAssetIdByChecksum.mockResolvedValue('dup-id');
+      mocks.stack.linkAsset.mockResolvedValue({ stackId: 'stack-1', created: false });
+
+      await expect(sut.uploadAsset(authStub.user1, { ...createDto, stackParentId: parent.id }, file)).resolves.toEqual({
+        id: 'dup-id',
+        status: AssetMediaStatus.DUPLICATE,
+      });
+
+      expect(mocks.stack.linkAsset).toHaveBeenCalledWith(authStub.user1.user.id, 'dup-id', parent.id);
+    });
+
     it('should hide the linked motion asset', async () => {
       const motionAsset = AssetFactory.from({ type: AssetType.Video }).owner(authStub.user1.user).build();
       const asset = AssetFactory.create();

server/src/services/asset-media.service.ts

@@ -140,26 +140,63 @@ export class AssetMediaService extends BaseService {
 
       this.requireQuota(auth, file.size);
 
+      if (dto.stackParentId) {
+        if (auth.sharedLink) {
+          throw new BadRequestException('Cannot stack an asset uploaded via shared link');
+        }
+        await this.requireAccess({ auth, permission: Permission.AssetUpdate, ids: [dto.stackParentId] });
+        const parent = await this.assetRepository.getById(dto.stackParentId);
+        if (!parent || parent.deletedAt) {
+          throw new BadRequestException('Cannot stack onto a trashed or missing asset');
+        }
+      }
+
       if (dto.livePhotoVideoId) {
         await onBeforeLink(
           { asset: this.assetRepository, event: this.eventRepository },
           { userId: auth.user.id, livePhotoVideoId: dto.livePhotoVideoId },
         );
       }
-      const asset = await this.create(auth.user.id, dto, file, sidecarFile);
+      // When stacking, defer the AssetCreate event and emit it below with the
+      // populated stackId, so clients don't briefly see the asset as standalone.
+      const asset = await this.create(auth.user.id, dto, file, sidecarFile, { skipEventEmit: !!dto.stackParentId });
 
       if (auth.sharedLink) {
         await this.addToSharedLink(auth.sharedLink, asset.id);
       }
 
+      if (dto.stackParentId) {
+        const linkResult = await this.linkToStackParent(auth.user.id, asset.id, dto.stackParentId);
+        await this.eventRepository.emit('AssetCreate', {
+          asset: linkResult ? { ...asset, stackId: linkResult.stackId } : asset,
+        });
+      }
+
       await this.userRepository.updateUsage(auth.user.id, file.size);
 
       return { id: asset.id, status: AssetMediaStatus.CREATED };
     } catch (error: any) {
-      return this.handleUploadError(error, auth, file, sidecarFile);
+      return this.handleUploadError(error, auth, file, sidecarFile, dto.stackParentId);
     }
   }
 
+  private async linkToStackParent(
+    ownerId: string,
+    newAssetId: string,
+    parentId: string,
+  ): Promise<{ stackId: string; created: boolean } | null> {
+    const result = await this.stackRepository.linkAsset(ownerId, newAssetId, parentId);
+    if (!result) {
+      this.logger.warn(`Could not link asset ${newAssetId} to stack parent ${parentId}: parent missing or not owned`);
+      return null;
+    }
+    await this.eventRepository.emit(result.created ? 'StackCreate' : 'StackUpdate', {
+      stackId: result.stackId,
+      userId: ownerId,
+    });
+    return result;
+  }
+
   async downloadOriginal(auth: AuthDto, id: string, dto: AssetDownloadOriginalDto): Promise<ImmichFileResponse> {
     await this.requireAccess({ auth, permission: Permission.AssetDownload, ids: [id] });
 
@@ -290,6 +327,7 @@ export class AssetMediaService extends BaseService {
     auth: AuthDto,
     file: UploadFile,
     sidecarFile?: UploadFile,
+    stackParentId?: string,
   ): Promise<AssetMediaResponseDto> {
     // clean up files
     await this.jobRepository.queue({
@@ -309,6 +347,12 @@ export class AssetMediaService extends BaseService {
         await this.addToSharedLink(auth.sharedLink, duplicateId);
       }
 
+      if (stackParentId) {
+        // Adopt the existing duplicate into the stack so a re-uploaded edit still
+        // stacks instead of silently staying separate.
+        await this.linkToStackParent(auth.user.id, duplicateId, stackParentId);
+      }
+
       this.logger.debug(`Duplicate asset upload rejected: existing asset ${duplicateId}`);
       return { status: AssetMediaStatus.DUPLICATE, id: duplicateId };
     }
@@ -317,7 +361,13 @@ export class AssetMediaService extends BaseService {
     throw error;
   }
 
-  private async create(ownerId: string, dto: AssetMediaCreateDto, file: UploadFile, sidecarFile?: UploadFile) {
+  private async create(
+    ownerId: string,
+    dto: AssetMediaCreateDto,
+    file: UploadFile,
+    sidecarFile?: UploadFile,
+    options?: { skipEventEmit?: boolean },
+  ) {
     const asset = await this.assetRepository.create({
       ownerId,
       libraryId: null,
@@ -356,7 +406,9 @@ export class AssetMediaService extends BaseService {
       lockedPropertiesBehavior: 'override',
     });
 
-    await this.eventRepository.emit('AssetCreate', { asset });
+    if (!options?.skipEventEmit) {
+      await this.eventRepository.emit('AssetCreate', { asset });
+    }
 
     await this.jobRepository.queue({ name: JobName.AssetExtractMetadata, data: { id: asset.id, source: 'upload' } });
 

server/src/utils/database.ts

@@ -76,6 +76,12 @@ export const isAssetChecksumConstraint = (error: unknown) => {
   return (error as PostgresError)?.constraint_name === 'UQ_assets_owner_checksum';
 };
 
+export const STACK_PRIMARY_CONSTRAINT = 'stack_primaryAssetId_uq';
+
+export const isStackPrimaryConstraint = (error: unknown) => {
+  return (error as PostgresError)?.constraint_name === STACK_PRIMARY_CONSTRAINT;
+};
+
 export function withDefaultVisibility<O>(qb: SelectQueryBuilder<DB, 'asset', O>) {
   return qb.where('asset.visibility', 'in', [sql.lit(AssetVisibility.Archive), sql.lit(AssetVisibility.Timeline)]);
 }