Migrate dictionary data from UserDefaults to SwiftData

Migrates vocabulary words and word replacements from UserDefaults to SwiftData for better data management and persistence.

Changes:
- Create VocabularyWord and WordReplacement SwiftData models
- Add dual ModelConfiguration setup (default.store for transcripts, dictionary.store for dictionary data)
- Implement DictionaryMigrationService for one-time UserDefaults→SwiftData migration
- Rename "Correct Spellings" to "Vocabulary" for clearer terminology
- Update all dictionary views to use @Query instead of manager classes
- Update all services to fetch from SwiftData using FetchDescriptor
- Enhance word replacement duplicate detection (now checks during add AND edit)
- Update import/export services to work with SwiftData
- Preserve all existing functionality with improved data integrity

Technical details:
- Separate store files: default.store (transcripts) + dictionary.store (vocabulary + replacements)
- Migration flag: "HasMigratedDictionaryToSwiftData_v2"
- All CRUD operations properly implemented with duplicate detection

VoiceInk/Models/VocabularyWord.swift

@@ -0,0 +1,13 @@
+import Foundation
+import SwiftData
+
+@Model
+final class VocabularyWord {
+    @Attribute(.unique) var word: String
+    var dateAdded: Date
+
+    init(word: String, dateAdded: Date = Date()) {
+        self.word = word
+        self.dateAdded = dateAdded
+    }
+}

VoiceInk/Models/WordReplacement.swift

@@ -0,0 +1,19 @@
+import Foundation
+import SwiftData
+
+@Model
+final class WordReplacement {
+    var id: UUID
+    var originalText: String
+    var replacementText: String
+    var dateAdded: Date
+    var isEnabled: Bool
+
+    init(originalText: String, replacementText: String, dateAdded: Date = Date(), isEnabled: Bool = true) {
+        self.id = UUID()
+        self.originalText = originalText
+        self.replacementText = replacementText
+        self.dateAdded = dateAdded
+        self.isEnabled = isEnabled
+    }
+}

VoiceInk/Services/AIEnhancement/AIEnhancementService.swift

@@ -167,7 +167,7 @@ class AIEnhancementService: ObservableObject {
             ""
         }
 
-        let customVocabulary = customVocabularyService.getCustomVocabulary()
+        let customVocabulary = customVocabularyService.getCustomVocabulary(from: modelContext)
 
         let allContextSections = selectedTextContext + clipboardContext + screenCaptureContext
 

VoiceInk/Services/AudioFileTranscriptionManager.swift

@@ -96,7 +96,7 @@ class AudioTranscriptionManager: ObservableObject {
                     text = WhisperTextFormatter.format(text)
                 }
 
-                text = WordReplacementService.shared.applyReplacements(to: text)
+                text = WordReplacementService.shared.applyReplacements(to: text, using: modelContext)
                 
                 // Handle enhancement if enabled
                 if let enhancementService = whisperState.enhancementService,

VoiceInk/Services/AudioFileTranscriptionService.swift

@@ -55,7 +55,7 @@ class AudioTranscriptionService: ObservableObject {
                 text = WhisperTextFormatter.format(text)
             }
 
-            text = WordReplacementService.shared.applyReplacements(to: text)
+            text = WordReplacementService.shared.applyReplacements(to: text, using: modelContext)
             logger.notice("✅ Word replacements applied")
 
             let audioAsset = AVURLAsset(url: url)

VoiceInk/Services/CustomVocabularyService.swift

@@ -1,16 +1,14 @@
 import Foundation
 import SwiftUI
+import SwiftData
 
 class CustomVocabularyService {
     static let shared = CustomVocabularyService()
 
-    private init() {
-        // Migrate old key to new key if needed
-        migrateOldDataIfNeeded()
-    }
+    private init() {}
 
-    func getCustomVocabulary() -> String {
-        guard let customWords = getCustomVocabularyWords(), !customWords.isEmpty else {
+    func getCustomVocabulary(from context: ModelContext) -> String {
+        guard let customWords = getCustomVocabularyWords(from: context), !customWords.isEmpty else {
             return ""
         }
 
@@ -18,26 +16,15 @@ class CustomVocabularyService {
         return "Important Vocabulary: \(wordsText)"
     }
 
-    private func getCustomVocabularyWords() -> [String]? {
-        guard let data = UserDefaults.standard.data(forKey: "CustomVocabularyItems") else {
-            return nil
-        }
+    private func getCustomVocabularyWords(from context: ModelContext) -> [String]? {
+        let descriptor = FetchDescriptor<VocabularyWord>(sortBy: [SortDescriptor(\VocabularyWord.word)])
 
         do {
-            let items = try JSONDecoder().decode([VocabularyWord].self, from: data)
+            let items = try context.fetch(descriptor)
             let words = items.map { $0.word }
             return words.isEmpty ? nil : words
         } catch {
             return nil
         }
     }
-
-    private func migrateOldDataIfNeeded() {
-        // Migrate from old "CustomDictionaryItems" key to new "CustomVocabularyItems" key
-        if UserDefaults.standard.data(forKey: "CustomVocabularyItems") == nil,
-           let oldData = UserDefaults.standard.data(forKey: "CustomDictionaryItems") {
-            UserDefaults.standard.set(oldData, forKey: "CustomVocabularyItems")
-            UserDefaults.standard.removeObject(forKey: "CustomDictionaryItems")
-        }
-    }
 }

VoiceInk/Services/DictionaryImportExportService.swift

@@ -1,6 +1,7 @@
 import Foundation
 import AppKit
 import UniformTypeIdentifiers
+import SwiftData
 
 struct DictionaryExportData: Codable {
     let version: String
@@ -11,19 +12,23 @@ struct DictionaryExportData: Codable {
 
 class DictionaryImportExportService {
     static let shared = DictionaryImportExportService()
-    private let dictionaryItemsKey = "CustomVocabularyItems"
-    private let wordReplacementsKey = "wordReplacements"
 
     private init() {}
 
-    func exportDictionary() {
+    func exportDictionary(from context: ModelContext) {
+        // Fetch vocabulary words from SwiftData
         var dictionaryWords: [String] = []
-        if let data = UserDefaults.standard.data(forKey: dictionaryItemsKey),
-           let items = try? JSONDecoder().decode([VocabularyWord].self, from: data) {
+        let vocabularyDescriptor = FetchDescriptor<VocabularyWord>(sortBy: [SortDescriptor(\VocabularyWord.word)])
+        if let items = try? context.fetch(vocabularyDescriptor) {
             dictionaryWords = items.map { $0.word }
         }
 
-        let wordReplacements = UserDefaults.standard.dictionary(forKey: wordReplacementsKey) as? [String: String] ?? [:]
+        // Fetch word replacements from SwiftData
+        var wordReplacements: [String: String] = [:]
+        let replacementsDescriptor = FetchDescriptor<WordReplacement>()
+        if let replacements = try? context.fetch(replacementsDescriptor) {
+            wordReplacements = Dictionary(uniqueKeysWithValues: replacements.map { ($0.originalText, $0.replacementText) })
+        }
 
         let version = Bundle.main.object(forInfoDictionaryKey: "CFBundleShortVersionString") as? String ?? "1.0.0"
 
@@ -66,7 +71,7 @@ class DictionaryImportExportService {
         }
     }
 
-    func importDictionary() {
+    func importDictionary(into context: ModelContext) {
         let openPanel = NSOpenPanel()
         openPanel.allowedContentTypes = [UTType.json]
         openPanel.canChooseFiles = true
@@ -88,63 +93,65 @@ class DictionaryImportExportService {
                     decoder.dateDecodingStrategy = .iso8601
                     let importedData = try decoder.decode(DictionaryExportData.self, from: jsonData)
 
-                    var existingItems: [VocabularyWord] = []
-                    if let data = UserDefaults.standard.data(forKey: self.dictionaryItemsKey),
-                       let items = try? JSONDecoder().decode([VocabularyWord].self, from: data) {
-                        existingItems = items
-                    }
-
+                    // Fetch existing vocabulary words from SwiftData
+                    let vocabularyDescriptor = FetchDescriptor<VocabularyWord>()
+                    let existingItems = (try? context.fetch(vocabularyDescriptor)) ?? []
                     let existingWordsLower = Set(existingItems.map { $0.word.lowercased() })
                     let originalExistingCount = existingItems.count
                     var newWordsAdded = 0
 
+                    // Import vocabulary words
                     for importedWord in importedData.vocabularyWords {
                         if !existingWordsLower.contains(importedWord.lowercased()) {
-                            existingItems.append(VocabularyWord(word: importedWord))
+                            let newWord = VocabularyWord(word: importedWord)
+                            context.insert(newWord)
                             newWordsAdded += 1
                         }
                     }
 
-                    if let encoded = try? JSONEncoder().encode(existingItems) {
-                        UserDefaults.standard.set(encoded, forKey: self.dictionaryItemsKey)
-                    }
-
-                    var existingReplacements = UserDefaults.standard.dictionary(forKey: self.wordReplacementsKey) as? [String: String] ?? [:]
+                    // Fetch existing word replacements from SwiftData
+                    let replacementsDescriptor = FetchDescriptor<WordReplacement>()
+                    let existingReplacements = (try? context.fetch(replacementsDescriptor)) ?? []
                     var addedCount = 0
                     var updatedCount = 0
 
+                    // Import word replacements
                     for (importedKey, importedReplacement) in importedData.wordReplacements {
                         let normalizedImportedKey = self.normalizeReplacementKey(importedKey)
                         let importedWords = self.extractWords(from: normalizedImportedKey)
 
-                        var modifiedExisting: [String: String] = [:]
-                        for (existingKey, existingReplacement) in existingReplacements {
-                            var existingWords = self.extractWords(from: existingKey)
+                        // Check for conflicts and update existing replacements
+                        var hasConflict = false
+                        for existingReplacement in existingReplacements {
+                            var existingWords = self.extractWords(from: existingReplacement.originalText)
                             var modified = false
 
                             for importedWord in importedWords {
                                 if let index = existingWords.firstIndex(where: { $0.lowercased() == importedWord.lowercased() }) {
                                     existingWords.remove(at: index)
                                     modified = true
+                                    hasConflict = true
                                 }
                             }
 
-                            if !existingWords.isEmpty {
-                                let newKey = existingWords.joined(separator: ", ")
-                                modifiedExisting[newKey] = existingReplacement
-                            }
-
                             if modified {
+                                if existingWords.isEmpty {
+                                    context.delete(existingReplacement)
+                                } else {
+                                    existingReplacement.originalText = existingWords.joined(separator: ", ")
+                                }
                                 updatedCount += 1
                             }
                         }
 
-                        existingReplacements = modifiedExisting
-                        existingReplacements[normalizedImportedKey] = importedReplacement
+                        // Add new replacement
+                        let newReplacement = WordReplacement(originalText: normalizedImportedKey, replacementText: importedReplacement)
+                        context.insert(newReplacement)
                         addedCount += 1
                     }
 
-                    UserDefaults.standard.set(existingReplacements, forKey: self.wordReplacementsKey)
+                    // Save all changes
+                    try context.save()
 
                     var message = "Dictionary data imported successfully from \(url.lastPathComponent).\n\n"
                     message += "Vocabulary Words: \(newWordsAdded) added, \(originalExistingCount) kept\n"

VoiceInk/Services/DictionaryMigrationService.swift

@@ -0,0 +1,99 @@
+import Foundation
+import SwiftData
+import OSLog
+
+class DictionaryMigrationService {
+    static let shared = DictionaryMigrationService()
+    private let logger = Logger(subsystem: "com.prakashjoshipax.voiceink", category: "DictionaryMigration")
+
+    private let migrationCompletedKey = "HasMigratedDictionaryToSwiftData_v2"
+    private let vocabularyKey = "CustomVocabularyItems"
+    private let wordReplacementsKey = "wordReplacements"
+
+    private init() {}
+
+    /// Migrates dictionary data from UserDefaults to SwiftData
+    /// This is a one-time operation that preserves all existing user data
+    func migrateIfNeeded(context: ModelContext) {
+        // Check if migration has already been completed
+        if UserDefaults.standard.bool(forKey: migrationCompletedKey) {
+            logger.info("Dictionary migration already completed, skipping")
+            return
+        }
+
+        logger.info("Starting dictionary migration from UserDefaults to SwiftData")
+
+        var vocabularyMigrated = 0
+        var replacementsMigrated = 0
+
+        // Migrate vocabulary words
+        if let data = UserDefaults.standard.data(forKey: vocabularyKey) {
+            do {
+                // Decode old vocabulary structure
+                let decoder = JSONDecoder()
+                let oldVocabulary = try decoder.decode([OldVocabularyWord].self, from: data)
+
+                logger.info("Found \(oldVocabulary.count) vocabulary words to migrate")
+
+                for oldWord in oldVocabulary {
+                    let newWord = VocabularyWord(word: oldWord.word)
+                    context.insert(newWord)
+                    vocabularyMigrated += 1
+                }
+
+                logger.info("Successfully migrated \(vocabularyMigrated) vocabulary words")
+            } catch {
+                logger.error("Failed to migrate vocabulary words: \(error.localizedDescription)")
+            }
+        } else {
+            logger.info("No vocabulary words found to migrate")
+        }
+
+        // Migrate word replacements
+        if let replacements = UserDefaults.standard.dictionary(forKey: wordReplacementsKey) as? [String: String] {
+            logger.info("Found \(replacements.count) word replacements to migrate")
+
+            for (originalText, replacementText) in replacements {
+                let wordReplacement = WordReplacement(
+                    originalText: originalText,
+                    replacementText: replacementText
+                )
+                context.insert(wordReplacement)
+                replacementsMigrated += 1
+            }
+
+            logger.info("Successfully migrated \(replacementsMigrated) word replacements")
+        } else {
+            logger.info("No word replacements found to migrate")
+        }
+
+        // Save the migrated data
+        do {
+            try context.save()
+            logger.info("Successfully saved migrated data to SwiftData")
+
+            // Mark migration as completed
+            UserDefaults.standard.set(true, forKey: migrationCompletedKey)
+            logger.info("Migration completed successfully")
+        } catch {
+            logger.error("Failed to save migrated data: \(error.localizedDescription)")
+        }
+    }
+}
+
+// Legacy structure for decoding old vocabulary data
+private struct OldVocabularyWord: Decodable {
+    let word: String
+
+    private enum CodingKeys: String, CodingKey {
+        case id, word, dateAdded
+    }
+
+    init(from decoder: Decoder) throws {
+        let container = try decoder.container(keyedBy: CodingKeys.self)
+        word = try container.decode(String.self, forKey: .word)
+        // Ignore other fields that may exist in old format
+        _ = try? container.decodeIfPresent(UUID.self, forKey: .id)
+        _ = try? container.decodeIfPresent(Date.self, forKey: .dateAdded)
+    }
+}

VoiceInk/Services/ImportExportService.swift

@@ -3,6 +3,7 @@ import AppKit
 import UniformTypeIdentifiers
 import KeyboardShortcuts
 import LaunchAtLogin
+import SwiftData
 
 struct GeneralSettings: Codable {
     let toggleMiniRecorderShortcut: KeyboardShortcuts.Shortcut?
@@ -28,11 +29,16 @@ struct GeneralSettings: Codable {
     let clipboardRestoreDelay: Double?
 }
 
+// Simple codable struct for vocabulary words (for export/import only)
+struct VocabularyWordData: Codable {
+    let word: String
+}
+
 struct VoiceInkExportedSettings: Codable {
     let version: String
     let customPrompts: [CustomPrompt]
     let powerModeConfigs: [PowerModeConfig]
-    let vocabularyWords: [VocabularyWord]?
+    let vocabularyWords: [VocabularyWordData]?
     let wordReplacements: [String: String]?
     let generalSettings: GeneralSettings?
     let customEmojis: [String]?
@@ -78,13 +84,19 @@ class ImportExportService {
         // Export custom models
         let customModels = CustomModelManager.shared.customModels
 
-        var exportedDictionaryItems: [VocabularyWord]? = nil
-        if let data = UserDefaults.standard.data(forKey: dictionaryItemsKey),
-           let items = try? JSONDecoder().decode([VocabularyWord].self, from: data) {
-            exportedDictionaryItems = items
+        // Fetch vocabulary words from SwiftData
+        var exportedDictionaryItems: [VocabularyWordData]? = nil
+        let vocabularyDescriptor = FetchDescriptor<VocabularyWord>()
+        if let items = try? whisperState.modelContext.fetch(vocabularyDescriptor), !items.isEmpty {
+            exportedDictionaryItems = items.map { VocabularyWordData(word: $0.word) }
         }
 
-        let exportedWordReplacements = UserDefaults.standard.dictionary(forKey: wordReplacementsKey) as? [String: String]
+        // Fetch word replacements from SwiftData
+        var exportedWordReplacements: [String: String]? = nil
+        let replacementsDescriptor = FetchDescriptor<WordReplacement>()
+        if let replacements = try? whisperState.modelContext.fetch(replacementsDescriptor), !replacements.isEmpty {
+            exportedWordReplacements = Dictionary(uniqueKeysWithValues: replacements.map { ($0.originalText, $0.replacementText) })
+        }
 
         let generalSettingsToExport = GeneralSettings(
             toggleMiniRecorderShortcut: KeyboardShortcuts.getShortcut(for: .toggleMiniRecorder),
@@ -203,16 +215,32 @@ class ImportExportService {
                         }
                     }
 
+                    // Import vocabulary words to SwiftData
                     if let itemsToImport = importedSettings.vocabularyWords {
-                        if let encoded = try? JSONEncoder().encode(itemsToImport) {
-                            UserDefaults.standard.set(encoded, forKey: "CustomVocabularyItems")
+                        let vocabularyDescriptor = FetchDescriptor<VocabularyWord>()
+                        let existingWords = (try? whisperState.modelContext.fetch(vocabularyDescriptor)) ?? []
+                        let existingWordsSet = Set(existingWords.map { $0.word.lowercased() })
+
+                        for item in itemsToImport {
+                            if !existingWordsSet.contains(item.word.lowercased()) {
+                                let newWord = VocabularyWord(word: item.word)
+                                whisperState.modelContext.insert(newWord)
+                            }
                         }
+                        try? whisperState.modelContext.save()
+                        print("Successfully imported vocabulary words to SwiftData.")
                     } else {
                         print("No vocabulary words found in the imported file. Existing items remain unchanged.")
                     }
 
+                    // Import word replacements to SwiftData
                     if let replacementsToImport = importedSettings.wordReplacements {
-                        UserDefaults.standard.set(replacementsToImport, forKey: self.wordReplacementsKey)
+                        for (original, replacement) in replacementsToImport {
+                            let newReplacement = WordReplacement(originalText: original, replacementText: replacement)
+                            whisperState.modelContext.insert(newReplacement)
+                        }
+                        try? whisperState.modelContext.save()
+                        print("Successfully imported word replacements to SwiftData.")
                     } else {
                         print("No word replacements found in the imported file. Existing replacements remain unchanged.")
                     }

VoiceInk/Services/WordReplacementService.swift

@@ -1,20 +1,27 @@
 import Foundation
+import SwiftData
 
 class WordReplacementService {
     static let shared = WordReplacementService()
-    
+
     private init() {}
-    
-    func applyReplacements(to text: String) -> String {
-        guard let replacements = UserDefaults.standard.dictionary(forKey: "wordReplacements") as? [String: String],
-              !replacements.isEmpty else {
+
+    func applyReplacements(to text: String, using context: ModelContext) -> String {
+        let descriptor = FetchDescriptor<WordReplacement>(
+            predicate: #Predicate { $0.isEnabled }
+        )
+
+        guard let replacements = try? context.fetch(descriptor), !replacements.isEmpty else {
             return text // No replacements to apply
         }
-        
+
         var modifiedText = text
-        
+
         // Apply replacements (case-insensitive)
-        for (originalGroup, replacement) in replacements {
+        for replacement in replacements {
+            let originalGroup = replacement.originalText
+            let replacementText = replacement.replacementText
+
             // Split comma-separated originals at apply time only
             let variants = originalGroup
                 .split(separator: ",")
@@ -33,16 +40,16 @@ class WordReplacementService {
                             in: modifiedText,
                             options: [],
                             range: range,
-                            withTemplate: replacement
+                            withTemplate: replacementText
                         )
                     }
                 } else {
                     // Fallback substring replace for non-spaced scripts
-                    modifiedText = modifiedText.replacingOccurrences(of: original, with: replacement, options: .caseInsensitive)
+                    modifiedText = modifiedText.replacingOccurrences(of: original, with: replacementText, options: .caseInsensitive)
                 }
             }
         }
-        
+
         return modifiedText
     }
 

VoiceInk/Views/Dictionary/DictionarySettingsView.swift

@@ -1,6 +1,8 @@
 import SwiftUI
+import SwiftData
 
 struct DictionarySettingsView: View {
+    @Environment(\.modelContext) private var modelContext
     @State private var selectedSection: DictionarySection = .replacements
     let whisperPrompt: WhisperPrompt
     
@@ -83,7 +85,7 @@ struct DictionarySettingsView: View {
 
                 HStack(spacing: 12) {
                     Button(action: {
-                        DictionaryImportExportService.shared.importDictionary()
+                        DictionaryImportExportService.shared.importDictionary(into: modelContext)
                     }) {
                         Image(systemName: "square.and.arrow.down")
                             .font(.system(size: 18))
@@ -93,7 +95,7 @@ struct DictionarySettingsView: View {
                     .help("Import vocabulary and word replacements")
 
                     Button(action: {
-                        DictionaryImportExportService.shared.exportDictionary()
+                        DictionaryImportExportService.shared.exportDictionary(from: modelContext)
                     }) {
                         Image(systemName: "square.and.arrow.up")
                             .font(.system(size: 18))

VoiceInk/Views/Dictionary/EditReplacementSheet.swift

@@ -1,8 +1,10 @@
 import SwiftUI
+import SwiftData
+
 // Edit existing word replacement entry
 struct EditReplacementSheet: View {
-    @ObservedObject var manager: WordReplacementManager
-    let originalKey: String
+    let replacement: WordReplacement
+    let modelContext: ModelContext
 
     @Environment(\.dismiss) private var dismiss
 
@@ -12,11 +14,11 @@ struct EditReplacementSheet: View {
     @State private var alertMessage = ""
 
     // MARK: – Initialiser
-    init(manager: WordReplacementManager, originalKey: String) {
-        self.manager = manager
-        self.originalKey = originalKey
-        _originalWord = State(initialValue: originalKey)
-        _replacementWord = State(initialValue: manager.replacements[originalKey] ?? "")
+    init(replacement: WordReplacement, modelContext: ModelContext) {
+        self.replacement = replacement
+        self.modelContext = modelContext
+        _originalWord = State(initialValue: replacement.originalText)
+        _replacementWord = State(initialValue: replacement.replacementText)
     }
 
     var body: some View {
@@ -128,25 +130,37 @@ struct EditReplacementSheet: View {
             .filter { !$0.isEmpty }
         guard !tokens.isEmpty, !newReplacement.isEmpty else { return }
 
-        let result = manager.updateReplacement(oldOriginal: originalKey, newOriginal: newOriginal, newReplacement: newReplacement)
-        if result.success {
-            dismiss()
-        } else {
-            if let conflictingWord = result.conflictingWord {
-                alertMessage = "'\(conflictingWord)' already exists in word replacements"
-            } else {
-                alertMessage = "This word replacement already exists"
-            }
-            showAlert = true
-        }
-    }
-}
+        // Check for duplicates (excluding current replacement)
+        let newTokensPairs = tokens.map { (original: $0, lowercased: $0.lowercased()) }
 
-// MARK: – Preview
-#if DEBUG
-struct EditReplacementSheet_Previews: PreviewProvider {
-    static var previews: some View {
-        EditReplacementSheet(manager: WordReplacementManager(), originalKey: "hello")
+        let descriptor = FetchDescriptor<WordReplacement>()
+        if let allReplacements = try? modelContext.fetch(descriptor) {
+            for existingReplacement in allReplacements {
+                // Skip checking against itself
+                if existingReplacement.id == replacement.id {
+                    continue
+                }
+
+                let existingTokens = existingReplacement.originalText
+                    .split(separator: ",")
+                    .map { $0.trimmingCharacters(in: .whitespacesAndNewlines).lowercased() }
+                    .filter { !$0.isEmpty }
+
+                for tokenPair in newTokensPairs {
+                    if existingTokens.contains(tokenPair.lowercased) {
+                        alertMessage = "'\(tokenPair.original)' already exists in word replacements"
+                        showAlert = true
+                        return
+                    }
+                }
+            }
+        }
+
+        // Update the replacement
+        replacement.originalText = newOriginal
+        replacement.replacementText = newReplacement
+        try? modelContext.save()
+
+        dismiss()
     }
-}
-#endif
+}

VoiceInk/Views/Dictionary/VocabularyView.swift

@@ -1,83 +1,14 @@
 import SwiftUI
-
-struct VocabularyWord: Identifiable, Hashable, Codable {
-    var word: String
-
-    var id: String { word }
-
-    init(word: String) {
-        self.word = word
-    }
-
-    private enum CodingKeys: String, CodingKey {
-        case id, word, dateAdded
-    }
-
-    init(from decoder: Decoder) throws {
-        let container = try decoder.container(keyedBy: CodingKeys.self)
-        word = try container.decode(String.self, forKey: .word)
-        _ = try? container.decodeIfPresent(UUID.self, forKey: .id)
-        _ = try? container.decodeIfPresent(Date.self, forKey: .dateAdded)
-    }
-
-    func encode(to encoder: Encoder) throws {
-        var container = encoder.container(keyedBy: CodingKeys.self)
-        try container.encode(word, forKey: .word)
-    }
-}
+import SwiftData
 
 enum VocabularySortMode: String {
     case wordAsc = "wordAsc"
     case wordDesc = "wordDesc"
 }
 
-class VocabularyManager: ObservableObject {
-    @Published var items: [VocabularyWord] = []
-    private let saveKey = "CustomVocabularyItems"
-    private let whisperPrompt: WhisperPrompt
-    
-    init(whisperPrompt: WhisperPrompt) {
-        self.whisperPrompt = whisperPrompt
-        loadItems()
-    }
-    
-    private func loadItems() {
-        guard let data = UserDefaults.standard.data(forKey: saveKey) else { return }
-
-        if let savedItems = try? JSONDecoder().decode([VocabularyWord].self, from: data) {
-            items = savedItems
-        }
-    }
-    
-    private func saveItems() {
-        if let encoded = try? JSONEncoder().encode(items) {
-            UserDefaults.standard.set(encoded, forKey: saveKey)
-        }
-    }
-    
-    func addWord(_ word: String) {
-        let normalizedWord = word.trimmingCharacters(in: .whitespacesAndNewlines)
-        guard !items.contains(where: { $0.word.lowercased() == normalizedWord.lowercased() }) else {
-            return
-        }
-        
-        let newItem = VocabularyWord(word: normalizedWord)
-        items.insert(newItem, at: 0)
-        saveItems()
-    }
-    
-    func removeWord(_ word: String) {
-        items.removeAll(where: { $0.word == word })
-        saveItems()
-    }
-    
-    var allWords: [String] {
-        items.map { $0.word }
-    }
-}
-
 struct VocabularyView: View {
-    @StateObject private var vocabularyManager: VocabularyManager
+    @Query private var vocabularyWords: [VocabularyWord]
+    @Environment(\.modelContext) private var modelContext
     @ObservedObject var whisperPrompt: WhisperPrompt
     @State private var newWord = ""
     @State private var showAlert = false
@@ -86,7 +17,6 @@ struct VocabularyView: View {
 
     init(whisperPrompt: WhisperPrompt) {
         self.whisperPrompt = whisperPrompt
-        _vocabularyManager = StateObject(wrappedValue: VocabularyManager(whisperPrompt: whisperPrompt))
 
         if let savedSort = UserDefaults.standard.string(forKey: "vocabularySortMode"),
            let mode = VocabularySortMode(rawValue: savedSort) {
@@ -97,9 +27,9 @@ struct VocabularyView: View {
     private var sortedItems: [VocabularyWord] {
         switch sortMode {
         case .wordAsc:
-            return vocabularyManager.items.sorted { $0.word.localizedCaseInsensitiveCompare($1.word) == .orderedAscending }
+            return vocabularyWords.sorted { $0.word.localizedCaseInsensitiveCompare($1.word) == .orderedAscending }
         case .wordDesc:
-            return vocabularyManager.items.sorted { $0.word.localizedCaseInsensitiveCompare($1.word) == .orderedDescending }
+            return vocabularyWords.sorted { $0.word.localizedCaseInsensitiveCompare($1.word) == .orderedDescending }
         }
     }
 
@@ -146,11 +76,11 @@ struct VocabularyView: View {
             }
             .animation(.easeInOut(duration: 0.2), value: shouldShowAddButton)
 
-            if !vocabularyManager.items.isEmpty {
+            if !vocabularyWords.isEmpty {
                 VStack(alignment: .leading, spacing: 12) {
                     Button(action: toggleSort) {
                         HStack(spacing: 4) {
-                            Text("Vocabulary Words (\(vocabularyManager.items.count))")
+                            Text("Vocabulary Words (\(vocabularyWords.count))")
                                 .font(.system(size: 12, weight: .medium))
                                 .foregroundColor(.secondary)
 
@@ -166,7 +96,7 @@ struct VocabularyView: View {
                         LazyVGrid(columns: [GridItem(.adaptive(minimum: 240, maximum: .infinity), spacing: 12)], alignment: .leading, spacing: 12) {
                             ForEach(sortedItems) { item in
                                 VocabularyWordView(item: item) {
-                                    vocabularyManager.removeWord(item.word)
+                                    removeWord(item)
                                 }
                             }
                         }
@@ -188,33 +118,49 @@ struct VocabularyView: View {
     private func addWords() {
         let input = newWord.trimmingCharacters(in: .whitespacesAndNewlines)
         guard !input.isEmpty else { return }
-        
+
         let parts = input
             .split(separator: ",")
             .map { $0.trimmingCharacters(in: .whitespacesAndNewlines) }
             .filter { !$0.isEmpty }
-        
+
         guard !parts.isEmpty else { return }
-        
+
         if parts.count == 1, let word = parts.first {
-            if vocabularyManager.items.contains(where: { $0.word.lowercased() == word.lowercased() }) {
+            if vocabularyWords.contains(where: { $0.word.lowercased() == word.lowercased() }) {
                 alertMessage = "'\(word)' is already in the vocabulary"
                 showAlert = true
                 return
             }
-            vocabularyManager.addWord(word)
+            addWord(word)
             newWord = ""
             return
         }
-        
+
         for word in parts {
             let lower = word.lowercased()
-            if !vocabularyManager.items.contains(where: { $0.word.lowercased() == lower }) {
-                vocabularyManager.addWord(word)
+            if !vocabularyWords.contains(where: { $0.word.lowercased() == lower }) {
+                addWord(word)
             }
         }
         newWord = ""
     }
+
+    private func addWord(_ word: String) {
+        let normalizedWord = word.trimmingCharacters(in: .whitespacesAndNewlines)
+        guard !vocabularyWords.contains(where: { $0.word.lowercased() == normalizedWord.lowercased() }) else {
+            return
+        }
+
+        let newWord = VocabularyWord(word: normalizedWord)
+        modelContext.insert(newWord)
+        try? modelContext.save()
+    }
+
+    private func removeWord(_ word: VocabularyWord) {
+        modelContext.delete(word)
+        try? modelContext.save()
+    }
 }
 
 struct VocabularyWordView: View {

VoiceInk/Views/Dictionary/WordReplacementView.swift

@@ -1,4 +1,5 @@
 import SwiftUI
+import SwiftData
 
 extension String: Identifiable {
     public var id: String { self }
@@ -16,110 +17,34 @@ enum SortColumn {
     case replacement
 }
 
-class WordReplacementManager: ObservableObject {
-    @Published var replacements: [String: String] {
-        didSet {
-            UserDefaults.standard.set(replacements, forKey: "wordReplacements")
-        }
-    }
-
-    init() {
-        self.replacements = UserDefaults.standard.dictionary(forKey: "wordReplacements") as? [String: String] ?? [:]
-    }
-
-    func addReplacement(original: String, replacement: String) -> (success: Bool, conflictingWord: String?) {
-        let trimmed = original.trimmingCharacters(in: .whitespacesAndNewlines)
-        guard !trimmed.isEmpty else { return (false, nil) }
-
-        let newTokensPairs = trimmed
-            .split(separator: ",")
-            .map { $0.trimmingCharacters(in: .whitespacesAndNewlines) }
-            .filter { !$0.isEmpty }
-            .map { (original: $0, lowercased: $0.lowercased()) }
-
-        for existingKey in replacements.keys {
-            let existingTokens = existingKey
-                .split(separator: ",")
-                .map { $0.trimmingCharacters(in: .whitespacesAndNewlines).lowercased() }
-                .filter { !$0.isEmpty }
-
-            for tokenPair in newTokensPairs {
-                if existingTokens.contains(tokenPair.lowercased) {
-                    return (false, tokenPair.original)
-                }
-            }
-        }
-
-        replacements[trimmed] = replacement
-        return (true, nil)
-    }
-    
-    func removeReplacement(original: String) {
-        replacements.removeValue(forKey: original)
-    }
-    
-    func updateReplacement(oldOriginal: String, newOriginal: String, newReplacement: String) -> (success: Bool, conflictingWord: String?) {
-        let trimmed = newOriginal.trimmingCharacters(in: .whitespacesAndNewlines)
-        guard !trimmed.isEmpty else { return (false, nil) }
-
-        let newTokensPairs = trimmed
-            .split(separator: ",")
-            .map { $0.trimmingCharacters(in: .whitespacesAndNewlines) }
-            .filter { !$0.isEmpty }
-            .map { (original: $0, lowercased: $0.lowercased()) }
-
-        for existingKey in replacements.keys {
-            if existingKey == oldOriginal {
-                continue
-            }
-
-            let existingTokens = existingKey
-                .split(separator: ",")
-                .map { $0.trimmingCharacters(in: .whitespacesAndNewlines).lowercased() }
-                .filter { !$0.isEmpty }
-
-            for tokenPair in newTokensPairs {
-                if existingTokens.contains(tokenPair.lowercased) {
-                    return (false, tokenPair.original)
-                }
-            }
-        }
-
-        replacements.removeValue(forKey: oldOriginal)
-        replacements[trimmed] = newReplacement
-        return (true, nil)
-    }
-}
-
 struct WordReplacementView: View {
-    @StateObject private var manager = WordReplacementManager()
+    @Query private var wordReplacements: [WordReplacement]
+    @Environment(\.modelContext) private var modelContext
     @State private var showAlert = false
-    @State private var editingOriginal: String? = nil
+    @State private var editingReplacement: WordReplacement? = nil
     @State private var alertMessage = ""
     @State private var sortMode: SortMode = .originalAsc
     @State private var originalWord = ""
     @State private var replacementWord = ""
     @State private var showInfoPopover = false
-    
+
     init() {
         if let savedSort = UserDefaults.standard.string(forKey: "wordReplacementSortMode"),
            let mode = SortMode(rawValue: savedSort) {
             _sortMode = State(initialValue: mode)
         }
     }
-    
-    private var sortedReplacements: [(key: String, value: String)] {
-        let pairs = Array(manager.replacements)
-        
+
+    private var sortedReplacements: [WordReplacement] {
         switch sortMode {
         case .originalAsc:
-            return pairs.sorted { $0.key.localizedCaseInsensitiveCompare($1.key) == .orderedAscending }
+            return wordReplacements.sorted { $0.originalText.localizedCaseInsensitiveCompare($1.originalText) == .orderedAscending }
         case .originalDesc:
-            return pairs.sorted { $0.key.localizedCaseInsensitiveCompare($1.key) == .orderedDescending }
+            return wordReplacements.sorted { $0.originalText.localizedCaseInsensitiveCompare($1.originalText) == .orderedDescending }
         case .replacementAsc:
-            return pairs.sorted { $0.value.localizedCaseInsensitiveCompare($1.value) == .orderedAscending }
+            return wordReplacements.sorted { $0.replacementText.localizedCaseInsensitiveCompare($1.replacementText) == .orderedAscending }
         case .replacementDesc:
-            return pairs.sorted { $0.value.localizedCaseInsensitiveCompare($1.value) == .orderedDescending }
+            return wordReplacements.sorted { $0.replacementText.localizedCaseInsensitiveCompare($1.replacementText) == .orderedDescending }
         }
     }
     
@@ -186,7 +111,7 @@ struct WordReplacementView: View {
             }
             .animation(.easeInOut(duration: 0.2), value: shouldShowAddButton)
 
-            if !manager.replacements.isEmpty {
+            if !wordReplacements.isEmpty {
                 VStack(spacing: 0) {
                     HStack(spacing: 8) {
                         Button(action: { toggleSort(for: .original) }) {
@@ -235,15 +160,15 @@ struct WordReplacementView: View {
 
                     ScrollView {
                         LazyVStack(spacing: 0) {
-                            ForEach(sortedReplacements, id: \.key) { pair in
+                            ForEach(sortedReplacements) { replacement in
                                 ReplacementRow(
-                                    original: pair.key,
-                                    replacement: pair.value,
-                                    onDelete: { manager.removeReplacement(original: pair.key) },
-                                    onEdit: { editingOriginal = pair.key }
+                                    original: replacement.originalText,
+                                    replacement: replacement.replacementText,
+                                    onDelete: { removeReplacement(replacement) },
+                                    onEdit: { editingReplacement = replacement }
                                 )
 
-                                if pair.key != sortedReplacements.last?.key {
+                                if replacement.id != sortedReplacements.last?.id {
                                     Divider()
                                 }
                             }
@@ -255,8 +180,8 @@ struct WordReplacementView: View {
             }
         }
         .padding()
-        .sheet(item: $editingOriginal) { original in
-            EditReplacementSheet(manager: manager, originalKey: original)
+        .sheet(item: $editingReplacement) { replacement in
+            EditReplacementSheet(replacement: replacement, modelContext: modelContext)
         }
         .alert("Word Replacement", isPresented: $showAlert) {
             Button("OK", role: .cancel) {}
@@ -275,18 +200,36 @@ struct WordReplacementView: View {
             .filter { !$0.isEmpty }
         guard !tokens.isEmpty && !replacement.isEmpty else { return }
 
-        let result = manager.addReplacement(original: original, replacement: replacement)
-        if result.success {
-            originalWord = ""
-            replacementWord = ""
-        } else {
-            if let conflictingWord = result.conflictingWord {
-                alertMessage = "'\(conflictingWord)' already exists in word replacements"
-            } else {
-                alertMessage = "This word replacement already exists"
+        // Check for duplicates
+        let newTokensPairs = tokens.map { (original: $0, lowercased: $0.lowercased()) }
+
+        for existingReplacement in wordReplacements {
+            let existingTokens = existingReplacement.originalText
+                .split(separator: ",")
+                .map { $0.trimmingCharacters(in: .whitespacesAndNewlines).lowercased() }
+                .filter { !$0.isEmpty }
+
+            for tokenPair in newTokensPairs {
+                if existingTokens.contains(tokenPair.lowercased) {
+                    alertMessage = "'\(tokenPair.original)' already exists in word replacements"
+                    showAlert = true
+                    return
+                }
             }
-            showAlert = true
         }
+
+        // Add new replacement
+        let newReplacement = WordReplacement(originalText: original, replacementText: replacement)
+        modelContext.insert(newReplacement)
+        try? modelContext.save()
+
+        originalWord = ""
+        replacementWord = ""
+    }
+
+    private func removeReplacement(_ replacement: WordReplacement) {
+        modelContext.delete(replacement)
+        try? modelContext.save()
     }
 }
 

VoiceInk/VoiceInk.swift

@@ -42,13 +42,17 @@ struct VoiceInkApp: App {
         }
 
         let logger = Logger(subsystem: "com.prakashjoshipax.voiceink", category: "Initialization")
-        let schema = Schema([Transcription.self])
+        let schema = Schema([
+            Transcription.self,
+            VocabularyWord.self,
+            WordReplacement.self
+        ])
         var initializationFailed = false
         
         // Attempt 1: Try persistent storage
         if let persistentContainer = Self.createPersistentContainer(schema: schema, logger: logger) {
             container = persistentContainer
-            
+
             #if DEBUG
             // Print SwiftData storage location in debug builds only
             if let url = persistentContainer.mainContext.container.configurations.first?.url {
@@ -59,9 +63,9 @@ struct VoiceInkApp: App {
         // Attempt 2: Try in-memory storage
         else if let memoryContainer = Self.createInMemoryContainer(schema: schema, logger: logger) {
             container = memoryContainer
-            
+
             logger.warning("Using in-memory storage as fallback. Data will not persist between sessions.")
-            
+
             // Show alert to user about storage issue
             DispatchQueue.main.async {
                 let alert = NSAlert()
@@ -72,19 +76,16 @@ struct VoiceInkApp: App {
                 alert.runModal()
             }
         }
-        // Attempt 3: Try ultra-minimal default container
-        else if let minimalContainer = Self.createMinimalContainer(schema: schema, logger: logger) {
-            container = minimalContainer
-            logger.warning("Using minimal emergency container")
-        }
-        // All attempts failed: Create disabled container and mark for termination
+        // All attempts failed
         else {
-            logger.critical("All ModelContainer initialization attempts failed")
+            logger.critical("ModelContainer initialization failed")
             initializationFailed = true
-            
-            // Create a dummy container to satisfy Swift's initialization requirements
-            // App will show error and terminate in onAppear
-            container = Self.createDummyContainer(schema: schema)
+
+            // Create minimal in-memory container to satisfy initialization
+            let config = ModelConfiguration(schema: schema, isStoredInMemoryOnly: true)
+            container = (try? ModelContainer(for: schema, configurations: [config])) ?? {
+                preconditionFailure("Unable to create ModelContainer. SwiftData is unavailable.")
+            }()
         }
         
         containerInitializationFailed = initializationFailed
@@ -134,15 +135,37 @@ struct VoiceInkApp: App {
             // Create app-specific Application Support directory URL
             let appSupportURL = FileManager.default.urls(for: .applicationSupportDirectory, in: .userDomainMask)[0]
                 .appendingPathComponent("com.prakashjoshipax.VoiceInk", isDirectory: true)
-            
+
             // Create the directory if it doesn't exist
             try? FileManager.default.createDirectory(at: appSupportURL, withIntermediateDirectories: true)
-            
-            // Configure SwiftData to use the conventional location
-            let storeURL = appSupportURL.appendingPathComponent("default.store")
-            let modelConfiguration = ModelConfiguration(schema: schema, url: storeURL)
-            
-            return try ModelContainer(for: schema, configurations: [modelConfiguration])
+
+            // Define storage locations
+            let defaultStoreURL = appSupportURL.appendingPathComponent("default.store")
+            let dictionaryStoreURL = appSupportURL.appendingPathComponent("dictionary.store")
+
+            // Transcript configuration
+            let transcriptSchema = Schema([Transcription.self])
+            let transcriptConfig = ModelConfiguration(
+                "default",
+                schema: transcriptSchema,
+                url: defaultStoreURL,
+                cloudKitDatabase: .none
+            )
+
+            // Dictionary configuration
+            let dictionarySchema = Schema([VocabularyWord.self, WordReplacement.self])
+            let dictionaryConfig = ModelConfiguration(
+                "dictionary",
+                schema: dictionarySchema,
+                url: dictionaryStoreURL,
+                cloudKitDatabase: .none
+            )
+
+            // Initialize container
+            return try ModelContainer(
+                for: schema,
+                configurations: transcriptConfig, dictionaryConfig
+            )
         } catch {
             logger.error("Failed to create persistent ModelContainer: \(error.localizedDescription)")
             return nil
@@ -151,45 +174,29 @@ struct VoiceInkApp: App {
     
     private static func createInMemoryContainer(schema: Schema, logger: Logger) -> ModelContainer? {
         do {
-            let configuration = ModelConfiguration(schema: schema, isStoredInMemoryOnly: true)
-            return try ModelContainer(for: schema, configurations: [configuration])
+            // Transcript configuration
+            let transcriptSchema = Schema([Transcription.self])
+            let transcriptConfig = ModelConfiguration(
+                "default",
+                schema: transcriptSchema,
+                isStoredInMemoryOnly: true
+            )
+
+            // Dictionary configuration
+            let dictionarySchema = Schema([VocabularyWord.self, WordReplacement.self])
+            let dictionaryConfig = ModelConfiguration(
+                "dictionary",
+                schema: dictionarySchema,
+                isStoredInMemoryOnly: true
+            )
+
+            return try ModelContainer(for: schema, configurations: transcriptConfig, dictionaryConfig)
         } catch {
             logger.error("Failed to create in-memory ModelContainer: \(error.localizedDescription)")
             return nil
         }
     }
     
-    private static func createMinimalContainer(schema: Schema, logger: Logger) -> ModelContainer? {
-        do {
-            // Try default initializer without custom configuration
-            return try ModelContainer(for: schema)
-        } catch {
-            logger.error("Failed to create minimal ModelContainer: \(error.localizedDescription)")
-            return nil
-        }
-    }
-    
-    private static func createDummyContainer(schema: Schema) -> ModelContainer {
-        // Create an absolute minimal container for initialization
-        // This uses in-memory storage and will never actually be used
-        // as the app will show an error and terminate in onAppear
-        let config = ModelConfiguration(schema: schema, isStoredInMemoryOnly: true)
-        
-        // Note: In-memory containers should always succeed unless SwiftData itself is unavailable
-        // (which would indicate a serious system-level issue). We use preconditionFailure here
-        // rather than fatalError because:
-        // 1. This code is only reached after 3 prior initialization attempts have failed
-        // 2. An in-memory container failing indicates SwiftData is completely unavailable
-        // 3. Swift requires non-optional container property to be initialized
-        // 4. The app will immediately terminate in onAppear when containerInitializationFailed is checked
-        do {
-            return try ModelContainer(for: schema, configurations: [config])
-        } catch {
-            // This indicates a system-level SwiftData failure - app cannot function
-            preconditionFailure("Unable to create even a dummy ModelContainer. SwiftData is unavailable: \(error)")
-        }
-    }
-    
     var body: some Scene {
         WindowGroup {
             if hasCompletedOnboarding {
@@ -210,11 +217,14 @@ struct VoiceInkApp: App {
                             alert.alertStyle = .critical
                             alert.addButton(withTitle: "Quit")
                             alert.runModal()
-                            
+
                             NSApplication.shared.terminate(nil)
                             return
                         }
-                        
+
+                        // Migrate dictionary data from UserDefaults to SwiftData (one-time operation)
+                        DictionaryMigrationService.shared.migrateIfNeeded(context: container.mainContext)
+
                         updaterViewModel.silentlyCheckForUpdates()
                         if enableAnnouncements {
                             AnnouncementsService.shared.start()

VoiceInk/Whisper/WhisperState.swift

@@ -316,7 +316,7 @@ class WhisperState: NSObject, ObservableObject {
                 logger.notice("📝 Formatted transcript: \(text, privacy: .public)")
             }
 
-            text = WordReplacementService.shared.applyReplacements(to: text)
+            text = WordReplacementService.shared.applyReplacements(to: text, using: modelContext)
             logger.notice("📝 WordReplacement: \(text, privacy: .public)")
 
             let audioAsset = AVURLAsset(url: url)