diff --git a/docs/BACKLOG.md b/docs/BACKLOG.md
index 2c72ae9..fc54275 100644
--- a/docs/BACKLOG.md
+++ b/docs/BACKLOG.md
@@ -8,11 +8,10 @@
 _(nothing active — pick the next batch from below)_
 
 ## Deferred / future refinements
-- [ ] **P13c-2 — opt-in auto-tag-on-download.** The sibling of P13a-2/P13b-3: an opt-in (default-off) setting
-      to suggest tags for new downloads in the background. Unlike the passive summary/OCR enrichments, tags are
-      **user-curated** (they drive facets), so this should likely **suggest + post a "review tags" Activity
-      Inbox nudge** (or write into a marked "ai" namespace) rather than silently auto-apply LLM tags — decide
-      the apply-vs-review behaviour when planning it. *(From P13c.)*
+- [ ] **Library "hide / filter AI tags" facet.** P13c-2 marks AI-applied tags (`media_tags.source = 'ai'`)
+      and shows a ✦ on their chips, but the library tag facet (`watchDistinctTags`) treats them like any tag.
+      Add a "hide AI tags" / "AI-tagged only" filter (and maybe a bulk "remove all AI tags on this item") if
+      auto-tagging proves noisy. Also: promote an AI tag to 'user' when the user re-adds/keeps it. *(From P13c-2.)*
 - [ ] **AI tag casing/normalization.** `addTagToItem` trims but doesn't lowercase, so P13c's AI suggestions
       are lowercased while manual/graph tags keep their case (e.g. `Live` vs `live` can coexist). Consider a
       single normalization policy (case-fold on store, or a display-case + fold-key) if duplicate-case tags
diff --git a/docs/VERIFICATION.md b/docs/VERIFICATION.md
index a4c777a..fc4f115 100644
--- a/docs/VERIFICATION.md
+++ b/docs/VERIFICATION.md
@@ -977,6 +977,14 @@ entries, or verify after P11c lands.)*
 - [ ] On a **low-end** device the AI row is **absent** (the graph co-occurrence "Suggested" chips still work);
       with generation **not enabled**, the button routes to **AI settings** (on-ramp).
 
+### P13c-2 — Auto-tag on download  *(install `app-arm64-v8a-debug.apk`; needs a capable device)*
+- [ ] AI & graph settings → with generation enabled, the **Auto-tag new downloads** toggle is visible; enable
+      it. Finish a download (item with description/transcript) → sensible **AI tags are applied** + an
+      Activity Inbox entry ("N tags added"), **fully offline**. The tags show a **✦ marker** in the editor +
+      on item detail, and appear as **search facets**; any AI tag can be **deleted**.
+- [ ] A **manually-added** tag has no marker. **Default off:** downloads aren't auto-tagged; with generation
+      off there's a one-time "finish setting up auto-tagging" nudge; the queue still drains.
+
 ### P13 (later subphases)
 - [ ] **Transcription / summarization / translation / OCR** each work (capability-gated) and write
       results back to the item.
diff --git a/docs/design/P13-PLAN.md b/docs/design/P13-PLAN.md
index 85c32b2..9206be6 100644
--- a/docs/design/P13-PLAN.md
+++ b/docs/design/P13-PLAN.md
@@ -194,6 +194,25 @@ LLM-suggested tags feeding the **existing** tag system — builds directly on th
   (low hides / high shows). **Pending APK spot-check** (generate + apply on a real item offline). The
   generate→chips flow is APK-verified. Background **auto-tag-on-download is a deliberate follow-up (P13c-2)**.
 
+#### `[~]` P13c-2 — Opt-in auto-tag on download (marked AI) *(generation; APK)*
+Follow-up: the LLM **applies** tags to new downloads in the background, opt-in (default off). Because tags are
+user-curated (they drive facets), AI tags are **marked** (provenance) rather than silently mixed in.
+- **Schema v12→v13:** `MediaTags.source` (`withDefault('user')`); `addTagToItem(…, {source})` (insertOrIgnore
+  keeps an existing link's source → user tags never demoted); `watchAiTagNamesForItem` + provider.
+- **Settings** `autoTagOnDownload` (default off) + setter; `_AutoTagTile` in the generation card.
+- **Pure** `autoTagDecision` (skip/needsModel/tag). **Queue** (`_persistCompleted`, after auto-OCR): build
+  source from title + description/transcript/`ocrText`, `buildTagPrompt` → `generate` → `parseTagSuggestions`
+  (exclude applied) → `addTagToItem(source: 'ai')`; `tagCount`/`tagNeedsModel` in `_PersistResult`; an `ai`
+  inbox entry ("N tags added") or a "finish setup" nudge.
+- **Marking:** the editor + item-detail tag chips show `auto_awesome_outlined` on AI-sourced tags (via
+  `aiTagNamesForItemProvider`); AI tags appear as normal search facets.
+- **Status:** implemented (CI-green) — schema v13 (+ a defensive table-guard in the migration, mirroring the
+  v8 guard-add spirit, so partial older test DBs don't break); repo provenance + provider; settings + tile;
+  `autoTagDecision`; queue block + two inbox posts; chip marking in both surfaces. Tests: `autoTagDecision`,
+  repo provenance (only-ai set; user not demoted), v12→v13 migration, settings round-trip, queue (applied as
+  'ai' + entry; default-off no-op). **No deps.** **Pending APK spot-check** (real download → AI-marked tags +
+  facets, offline). A library "hide/filter AI tags" facet is deferred (BACKLOG).
+
 ### `[ ]` P13d — Local GraphRAG "Ask your library" *(flagship; split into 3 PRs)*
 The headline differentiator — natural-language Q&A grounded in the private library, fully on-device
 (AI-SPEC §6, GRAPH-SPEC §7). Sequenced **mid-phase** so the generation patterns (P13a/c) are proven first.
diff --git a/lib/core/db/database.dart b/lib/core/db/database.dart
index 983d007..ba95293 100644
--- a/lib/core/db/database.dart
+++ b/lib/core/db/database.dart
@@ -93,6 +93,9 @@ class MediaTags extends Table {
       text().references(MediaItems, #id, onDelete: KeyAction.cascade)();
   IntColumn get tagId =>
       integer().references(Tags, #id, onDelete: KeyAction.cascade)();
+  // P13c-2: provenance of this tag link — 'user' (manual/graph) or 'ai'
+  // (auto-applied on download). Lets AI tags be marked + managed distinctly.
+  TextColumn get source => text().withDefault(const Constant('user'))();
 
   @override
   Set<Column<Object>> get primaryKey => {itemId, tagId};
@@ -217,7 +220,7 @@ class AppDatabase extends _$AppDatabase {
     : super(executor ?? driftDatabase(name: 'grabbit'));
 
   @override
-  int get schemaVersion => 12;
+  int get schemaVersion => 13;
 
   @override
   MigrationStrategy get migration => MigrationStrategy(
@@ -286,6 +289,16 @@ class AppDatabase extends _$AppDatabase {
         }
         await customStatement('DROP TABLE IF EXISTS media_fts');
       }
+      if (from < 13) {
+        // P13c-2: tag provenance ('user' default; 'ai' for auto-applied tags).
+        // Defensive table guard (mirrors the v8 guard-add spirit): a no-op if
+        // media_tags somehow isn't present yet.
+        final hasMediaTags = (await customSelect(
+          "SELECT 1 FROM sqlite_master WHERE type='table' "
+          "AND name='media_tags'",
+        ).get()).isNotEmpty;
+        if (hasMediaTags) await m.addColumn(mediaTags, mediaTags.source);
+      }
       await _createIndices();
       await _createFtsObjects();
     },
diff --git a/lib/features/library/data/metadata_repository.dart b/lib/features/library/data/metadata_repository.dart
index f41ff0e..8cb0d99 100644
--- a/lib/features/library/data/metadata_repository.dart
+++ b/lib/features/library/data/metadata_repository.dart
@@ -718,7 +718,15 @@ class MetadataRepository {
     return [for (final r in rows) r.readTable(_db.tags).name];
   }
 
-  Future<void> addTagToItem(String itemId, String name) async {
+  /// Applies tag [name] to [itemId]. [source] records provenance — `'user'`
+  /// (manual/graph) or `'ai'` (auto-applied, P13c-2). `insertOrIgnore` means an
+  /// existing link keeps its original source, so a user-applied tag is never
+  /// demoted to `'ai'`.
+  Future<void> addTagToItem(
+    String itemId,
+    String name, {
+    String source = 'user',
+  }) async {
     final clean = name.trim();
     if (clean.isEmpty) return;
     await _db
@@ -733,11 +741,31 @@ class MetadataRepository {
     await _db
         .into(_db.mediaTags)
         .insert(
-          MediaTagsCompanion.insert(itemId: itemId, tagId: tag.id),
+          MediaTagsCompanion.insert(
+            itemId: itemId,
+            tagId: tag.id,
+            source: Value(source),
+          ),
           mode: InsertMode.insertOrIgnore,
         );
   }
 
+  /// The names of an item's **AI-applied** tags (P13c-2) — for marking them
+  /// distinctly in the UI. Reactive.
+  Stream<Set<String>> watchAiTagNamesForItem(String itemId) {
+    final query =
+        _db.select(_db.tags).join([
+          innerJoin(_db.mediaTags, _db.mediaTags.tagId.equalsExp(_db.tags.id)),
+        ])..where(
+          _db.mediaTags.itemId.equals(itemId) &
+              _db.mediaTags.source.equals('ai'),
+        );
+    return query
+        .map((row) => row.readTable(_db.tags).name)
+        .watch()
+        .map((names) => names.toSet());
+  }
+
   Future<void> removeTagFromItem(String itemId, int tagId) async {
     await (_db.delete(
       _db.mediaTags,
@@ -822,6 +850,12 @@ final tagsForItemProvider = StreamProvider.family<List<Tag>, String>(
       ref.watch(metadataRepositoryProvider).watchTagsForItem(itemId),
 );
 
+/// Names of an item's AI-applied tags (P13c-2), for marking them in the UI.
+final aiTagNamesForItemProvider = StreamProvider.family<Set<String>, String>(
+  (ref, itemId) =>
+      ref.watch(metadataRepositoryProvider).watchAiTagNamesForItem(itemId),
+);
+
 final collectionsProvider = StreamProvider<List<Collection>>(
   (ref) => ref.watch(metadataRepositoryProvider).watchCollections(),
 );
diff --git a/lib/features/library/presentation/item_detail_screen.dart b/lib/features/library/presentation/item_detail_screen.dart
index 547563c..2e1aff6 100644
--- a/lib/features/library/presentation/item_detail_screen.dart
+++ b/lib/features/library/presentation/item_detail_screen.dart
@@ -1646,6 +1646,9 @@ class _TagsRow extends ConsumerWidget {
   Widget build(BuildContext context, WidgetRef ref) {
     final tokens = GrabBitTokens.of(context);
     final tags = ref.watch(tagsForItemProvider(itemId));
+    final aiTags =
+        ref.watch(aiTagNamesForItemProvider(itemId)).asData?.value ??
+        const <String>{};
     return tags.maybeWhen(
       data: (list) => list.isEmpty
           ? const SizedBox.shrink()
@@ -1657,6 +1660,9 @@ class _TagsRow extends ConsumerWidget {
                 children: [
                   for (final t in list)
                     ActionChip(
+                      avatar: aiTags.contains(t.name)
+                          ? const Icon(Icons.auto_awesome_outlined, size: 16)
+                          : null,
                       label: Text(t.name),
                       onPressed: () => _openHub(context, 'tag', t.name, t.name),
                     ),
diff --git a/lib/features/library/presentation/metadata_edit_screen.dart b/lib/features/library/presentation/metadata_edit_screen.dart
index bc594ec..1d784f6 100644
--- a/lib/features/library/presentation/metadata_edit_screen.dart
+++ b/lib/features/library/presentation/metadata_edit_screen.dart
@@ -125,6 +125,9 @@ class _TagsEditor extends ConsumerWidget {
   Widget build(BuildContext context, WidgetRef ref) {
     final tokens = GrabBitTokens.of(context);
     final tags = ref.watch(tagsForItemProvider(itemId));
+    final aiTags =
+        ref.watch(aiTagNamesForItemProvider(itemId)).asData?.value ??
+        const <String>{};
     final repo = ref.read(metadataRepositoryProvider);
     return Column(
       crossAxisAlignment: CrossAxisAlignment.start,
@@ -148,6 +151,12 @@ class _TagsEditor extends ConsumerWidget {
                           children: [
                             for (final tag in list)
                               Chip(
+                                avatar: aiTags.contains(tag.name)
+                                    ? const Icon(
+                                        Icons.auto_awesome_outlined,
+                                        size: 16,
+                                      )
+                                    : null,
                                 label: Text(tag.name),
                                 onDeleted: () =>
                                     repo.removeTagFromItem(itemId, tag.id),
diff --git a/lib/features/library/presentation/tag_suggestions.dart b/lib/features/library/presentation/tag_suggestions.dart
index d6a2ad1..1d59e23 100644
--- a/lib/features/library/presentation/tag_suggestions.dart
+++ b/lib/features/library/presentation/tag_suggestions.dart
@@ -56,3 +56,28 @@ List<String> parseTagSuggestions(
   }
   return out;
 }
+
+/// What auto-tag-on-download (P13c-2) should do for a freshly downloaded item,
+/// assuming the feature + generation are opted in. A pure decision so the queue
+/// path is testable (mirrors `autoSummaryDecision`).
+enum AutoTagDecision {
+  /// Nothing to tag (no source text).
+  skip,
+
+  /// Would tag, but the generation model isn't downloaded — nudge once.
+  needsModel,
+
+  /// Generate + apply tags now (model ready).
+  tag,
+}
+
+/// [hasText] is whether the item has title/description/transcript/OCR to tag;
+/// [modelReady] is whether the generation model is downloaded (`ensureReady` —
+/// no fetch).
+AutoTagDecision autoTagDecision({
+  required bool hasText,
+  required bool modelReady,
+}) {
+  if (!hasText) return AutoTagDecision.skip;
+  return modelReady ? AutoTagDecision.tag : AutoTagDecision.needsModel;
+}
diff --git a/lib/features/queue/presentation/queue_controller.dart b/lib/features/queue/presentation/queue_controller.dart
index 0e61a3e..f40ac06 100644
--- a/lib/features/queue/presentation/queue_controller.dart
+++ b/lib/features/queue/presentation/queue_controller.dart
@@ -28,6 +28,7 @@ import 'package:grabbit/features/library/data/metadata_repository.dart';
 import 'package:grabbit/features/library/data/transcript_service.dart';
 import 'package:grabbit/features/library/presentation/ai_summary.dart';
 import 'package:grabbit/features/library/presentation/ocr.dart';
+import 'package:grabbit/features/library/presentation/tag_suggestions.dart';
 import 'package:grabbit/features/notifications/data/notification_enums.dart';
 import 'package:grabbit/features/notifications/data/notifications_repository.dart';
 import 'package:grabbit/features/notifications/data/system_notification_service.dart';
@@ -55,6 +56,10 @@ typedef _PersistResult = ({
   bool summaryNeedsModel,
   // P13b-3: count of image items auto-scanned for text (OCR).
   int ocrCount,
+  // P13c-2: count of items auto-tagged, and whether auto-tag is opted in but
+  // the generation model isn't downloaded → prompt to finish setup.
+  int tagCount,
+  bool tagNeedsModel,
 });
 
 class QueueConfig {
@@ -436,6 +441,31 @@ class QueueController extends _$QueueController {
         dedupeKey: 'ocr_$id',
       );
     }
+    // P13c-2: auto-tag applied AI tags to the new download.
+    if (result.tagCount > 0) {
+      await center.post(
+        category: NotificationCategory.ai,
+        severity: NotificationSeverity.success,
+        title: queued.title,
+        body: result.tagCount > 1
+            ? '${result.tagCount} tags added'
+            : 'Tag added',
+        targetRoute: route,
+        itemId: single ? result.primaryId : null,
+        dedupeKey: 'tags_$id',
+      );
+    }
+    // P13c-2: opted into auto-tagging but the generation model isn't downloaded.
+    if (result.tagNeedsModel) {
+      await center.post(
+        category: NotificationCategory.ai,
+        severity: NotificationSeverity.info,
+        title: 'Finish setting up auto-tagging',
+        body: 'Download a text-generation model to auto-tag new downloads.',
+        targetRoute: '/settings/ai',
+        dedupeKey: 'tags_needs_model',
+      );
+    }
     await _maybeNotifyOs(
       taskId: id,
       title: queued.title,
@@ -597,6 +627,8 @@ class QueueController extends _$QueueController {
       summaryCount: 0,
       summaryNeedsModel: false,
       ocrCount: 0,
+      tagCount: 0,
+      tagNeedsModel: false,
     );
     // Files land in a per-task subfolder (see YtDlpHost `-o`): the task id names
     // the folder, the user's template names the file inside it.
@@ -833,6 +865,60 @@ class QueueController extends _$QueueController {
       }
     }
 
+    // P13c-2: auto-apply LLM tags (marked 'ai') to freshly downloaded items
+    // when opted in + a generation model is already downloaded (no surprise
+    // fetch). Mirrors auto-summarize; per-item failures never fail the download.
+    var tagCount = 0;
+    var tagNeedsModel = false;
+    if (settings.autoTagOnDownload && settings.generationEnabled) {
+      final generation = ref.read(generationEngineProvider);
+      final genReady = await generation.ensureReady();
+      final metadata = ref.read(metadataRepositoryProvider);
+      for (final (i, _) in outputs.media.indexed) {
+        final itemId = single ? id : '${id}__$i';
+        final item = await metadata.mediaItemById(itemId);
+        final meta = await metadata.metadataForItem(itemId);
+        final src = [
+          if (item != null) item.title,
+          ?meta?.description,
+          ?meta?.transcript,
+          ?meta?.ocrText,
+        ].where((s) => s.trim().isNotEmpty).join('\n');
+        switch (autoTagDecision(
+          hasText: src.trim().isNotEmpty,
+          modelReady: genReady,
+        )) {
+          case AutoTagDecision.skip:
+            continue;
+          case AutoTagDecision.needsModel:
+            tagNeedsModel = true;
+            continue;
+          case AutoTagDecision.tag:
+            try {
+              final existing = await metadata.tagNamesForItem(itemId);
+              final p = buildTagPrompt(src);
+              final buffer = StringBuffer();
+              await for (final token in generation.generate(
+                p.prompt,
+                systemPrompt: p.systemPrompt,
+              )) {
+                buffer.write(token);
+              }
+              final tags = parseTagSuggestions(
+                buffer.toString(),
+                exclude: existing.toSet(),
+              );
+              for (final t in tags) {
+                await metadata.addTagToItem(itemId, t, source: 'ai');
+              }
+              tagCount += tags.length;
+            } catch (_) {
+              // A per-item tagging failure must not fail the download.
+            }
+        }
+      }
+    }
+
     return (
       primaryId: single ? id : '${id}__0',
       itemCount: outputs.media.length,
@@ -841,6 +927,8 @@ class QueueController extends _$QueueController {
       summaryCount: summaryCount,
       summaryNeedsModel: summaryNeedsModel,
       ocrCount: ocrCount,
+      tagCount: tagCount,
+      tagNeedsModel: tagNeedsModel,
     );
   }
 
diff --git a/lib/features/settings/data/settings_model.dart b/lib/features/settings/data/settings_model.dart
index c4cb842..9f22348 100644
--- a/lib/features/settings/data/settings_model.dart
+++ b/lib/features/settings/data/settings_model.dart
@@ -102,6 +102,10 @@ abstract class SettingsModel with _$SettingsModel {
     // images, on-device + offline (bundled ML Kit, no download). The on-demand
     // "Scan text" on item detail (P13b-1) works regardless.
     @Default(false) bool autoOcrOnDownload,
+    // P13c-2: auto-apply LLM-suggested tags to a newly downloaded item in the
+    // background (marked as 'ai', deletable). Opt-in (defaults off); runs only
+    // when text generation is enabled and its model is already downloaded.
+    @Default(false) bool autoTagOnDownload,
     // On-device speech transcription (P12e). Opt-in (defaults off); the whisper
     // model is downloaded only when the user enables it + picks a model.
     // `selectedTranscriptionModelId` empty = the device-tier recommendation;
diff --git a/lib/features/settings/presentation/ai_settings_screen.dart b/lib/features/settings/presentation/ai_settings_screen.dart
index 48b017f..93bbfa5 100644
--- a/lib/features/settings/presentation/ai_settings_screen.dart
+++ b/lib/features/settings/presentation/ai_settings_screen.dart
@@ -635,6 +635,7 @@ class _GenerationCard extends ConsumerWidget {
         children: [
           for (final m in eligible) _GenerationModelTile(model: m),
           const _AutoSummarizeTile(),
+          const _AutoTagTile(),
           const _GenerationSelfTestTile(),
         ],
       ),
@@ -683,6 +684,46 @@ class _AutoSummarizeTile extends ConsumerWidget {
   }
 }
 
+/// Opt-in (P13c-2): auto-apply LLM tags to new downloads in the background.
+/// Shown only when text generation is enabled; runs only when a model is
+/// downloaded. Auto-applied tags are marked as AI and can be deleted; the
+/// on-demand "Suggest tags with AI" in the editor works regardless.
+class _AutoTagTile extends ConsumerWidget {
+  const _AutoTagTile();
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final enabled = ref.watch(
+      settingsControllerProvider.select(
+        (s) => s.value?.generationEnabled ?? false,
+      ),
+    );
+    if (!enabled) return const SizedBox.shrink();
+    final auto = ref.watch(
+      settingsControllerProvider.select(
+        (s) => s.value?.autoTagOnDownload ?? false,
+      ),
+    );
+    return SwitchListTile(
+      secondary: const InfoHintButton(
+        InfoHint(
+          title: 'Auto-tag new downloads',
+          body:
+              'Add AI-suggested tags to each new download automatically, in the '
+              'background — all on-device. Runs only when a text-generation '
+              'model is downloaded. AI tags are marked with a ✦ and can be '
+              'deleted; you can always tag an item by hand.',
+        ),
+      ),
+      title: const Text('Auto-tag new downloads'),
+      subtitle: const Text('Tag each download in the background'),
+      value: auto,
+      onChanged: (v) =>
+          ref.read(settingsControllerProvider.notifier).setAutoTagOnDownload(v),
+    );
+  }
+}
+
 /// One selectable generation model row: badge (Recommended / size band) + size,
 /// a radio-like check for the active selection. Selecting it opts in + downloads
 /// (storage-guarded); selecting the active one again turns generation off.
diff --git a/lib/features/settings/presentation/settings_controller.dart b/lib/features/settings/presentation/settings_controller.dart
index 8e24d20..161d4ce 100644
--- a/lib/features/settings/presentation/settings_controller.dart
+++ b/lib/features/settings/presentation/settings_controller.dart
@@ -151,6 +151,10 @@ class SettingsController extends _$SettingsController {
   Future<void> setAutoOcrOnDownload(bool value) async =>
       _update((await future).copyWith(autoOcrOnDownload: value));
 
+  /// Auto-apply LLM tags to newly downloaded items in the background (P13c-2).
+  Future<void> setAutoTagOnDownload(bool value) async =>
+      _update((await future).copyWith(autoTagOnDownload: value));
+
   /// On-device transcription opt-in (P12e).
   Future<void> setTranscriptionEnabled(bool value) async =>
       _update((await future).copyWith(transcriptionEnabled: value));
diff --git a/test/core/db/database_test.dart b/test/core/db/database_test.dart
index 15586ca..d28f643 100644
--- a/test/core/db/database_test.dart
+++ b/test/core/db/database_test.dart
@@ -9,8 +9,8 @@ void main() {
   setUp(() => db = AppDatabase(NativeDatabase.memory()));
   tearDown(() => db.close());
 
-  test('opens at schema version 12 with all tables created', () async {
-    expect(db.schemaVersion, 12);
+  test('opens at schema version 13 with all tables created', () async {
+    expect(db.schemaVersion, 13);
 
     // Forces onCreate (createAll) + beforeOpen to run.
     final tableNames = db.allTables.map((t) => t.actualTableName).toSet();
@@ -1035,6 +1035,96 @@ void main() {
     },
   );
 
+  test(
+    'upgrades a v12 database to v13, adding media_tags.source (P13c-2)',
+    () async {
+      // Seed a minimal v12 DB with a media_tags row (no `source` column),
+      // user_version=12. Opening at v13 must add `source` defaulting 'user'.
+      final upgraded = AppDatabase(
+        NativeDatabase.memory(
+          setup: (raw) {
+            raw.execute('''
+              CREATE TABLE media_items (
+                id TEXT NOT NULL PRIMARY KEY, title TEXT NOT NULL,
+                source_url TEXT NOT NULL, site TEXT NOT NULL,
+                file_path TEXT NOT NULL, type TEXT NOT NULL, duration_sec INTEGER,
+                size_bytes INTEGER, width INTEGER, height INTEGER, thumb_path TEXT,
+                created_at INTEGER NOT NULL, storage_state TEXT NOT NULL, notes TEXT,
+                folder_id INTEGER, is_favorite INTEGER NOT NULL DEFAULT 0,
+                content_hash TEXT, last_accessed_at INTEGER
+              )''');
+            raw.execute('''
+              CREATE TABLE media_metadata (
+                item_id TEXT NOT NULL PRIMARY KEY REFERENCES media_items (id),
+                uploader TEXT, upload_date INTEGER, description TEXT,
+                original_url TEXT, uploader_id TEXT, channel_id TEXT, source_id TEXT,
+                playlist_id TEXT, playlist_title TEXT, tags TEXT, transcript TEXT,
+                transcript_cues TEXT, ai_summary TEXT, ai_summary_model_id TEXT,
+                ocr_text TEXT
+              )''');
+            raw.execute(
+              'CREATE TABLE tags (id INTEGER NOT NULL PRIMARY KEY '
+              'AUTOINCREMENT, name TEXT NOT NULL UNIQUE)',
+            );
+            // v12 media_tags — NO `source` column.
+            raw.execute('''
+              CREATE TABLE media_tags (
+                item_id TEXT NOT NULL REFERENCES media_items (id),
+                tag_id INTEGER NOT NULL REFERENCES tags (id),
+                PRIMARY KEY (item_id, tag_id)
+              )''');
+            // Tables the migration tail (_createIndices) touches.
+            raw.execute('''
+              CREATE TABLE notifications (
+                id TEXT NOT NULL PRIMARY KEY, category TEXT NOT NULL,
+                severity TEXT NOT NULL, title TEXT NOT NULL, body TEXT,
+                target_route TEXT, item_id TEXT, task_id TEXT, dedupe_key TEXT,
+                created_at INTEGER NOT NULL, updated_at INTEGER NOT NULL,
+                read_at INTEGER, expires_at INTEGER,
+                coalesce_count INTEGER NOT NULL DEFAULT 1
+              )''');
+            raw.execute(
+              'INSERT INTO media_items (id, title, source_url, site, '
+              'file_path, type, created_at, storage_state) VALUES '
+              "('old1', 'Clip', 'u', 's', '/m/o', 'video', 0, 'private')",
+            );
+            raw.execute("INSERT INTO tags (id, name) VALUES (1, 'legacy')");
+            raw.execute(
+              "INSERT INTO media_tags (item_id, tag_id) VALUES ('old1', 1)",
+            );
+            raw.execute('PRAGMA user_version = 12');
+          },
+        ),
+      );
+      addTearDown(upgraded.close);
+
+      // The pre-existing media_tag row defaults to 'user'.
+      final rows = await upgraded.select(upgraded.mediaTags).get();
+      expect(rows.single.source, 'user');
+
+      // A new AI-sourced link round-trips.
+      await upgraded
+          .into(upgraded.tags)
+          .insert(TagsCompanion.insert(name: 'rock'));
+      final rock = await (upgraded.select(
+        upgraded.tags,
+      )..where((t) => t.name.equals('rock'))).getSingle();
+      await upgraded
+          .into(upgraded.mediaTags)
+          .insert(
+            MediaTagsCompanion.insert(
+              itemId: 'old1',
+              tagId: rock.id,
+              source: const Value('ai'),
+            ),
+          );
+      final ai = await (upgraded.select(
+        upgraded.mediaTags,
+      )..where((t) => t.source.equals('ai'))).get();
+      expect(ai.single.tagId, rock.id);
+    },
+  );
+
   test(
     'addColumnIfMissing is idempotent and adds only absent columns',
     () async {
diff --git a/test/features/library/item_detail_screen_test.dart b/test/features/library/item_detail_screen_test.dart
index 65ce252..9c781a9 100644
--- a/test/features/library/item_detail_screen_test.dart
+++ b/test/features/library/item_detail_screen_test.dart
@@ -47,6 +47,9 @@ void main() {
             'x',
           ).overrideWith((ref) => Stream.value(metadata)),
           tagsForItemProvider('x').overrideWith((ref) => Stream.value(<Tag>[])),
+          aiTagNamesForItemProvider(
+            'x',
+          ).overrideWith((ref) => Stream.value(<String>{})),
           collectionsForItemProvider(
             'x',
           ).overrideWith((ref) => Stream.value(<Collection>[])),
@@ -116,6 +119,9 @@ void main() {
             tagsForItemProvider(
               'x',
             ).overrideWith((ref) => Stream.value(<Tag>[])),
+            aiTagNamesForItemProvider(
+              'x',
+            ).overrideWith((ref) => Stream.value(<String>{})),
             collectionsForItemProvider(
               'x',
             ).overrideWith((ref) => Stream.value(<Collection>[])),
@@ -152,6 +158,9 @@ void main() {
             tagsForItemProvider('x').overrideWith(
               (ref) => Stream.value([const Tag(id: 1, name: 'funny')]),
             ),
+            aiTagNamesForItemProvider(
+              'x',
+            ).overrideWith((ref) => Stream.value(<String>{})),
             collectionsForItemProvider(
               'x',
             ).overrideWith((ref) => Stream.value(<Collection>[])),
@@ -183,6 +192,9 @@ void main() {
             tagsForItemProvider(
               'x',
             ).overrideWith((ref) => Stream.value(<Tag>[])),
+            aiTagNamesForItemProvider(
+              'x',
+            ).overrideWith((ref) => Stream.value(<String>{})),
             collectionsForItemProvider('x').overrideWith(
               (ref) => Stream.value([
                 Collection(id: 7, name: 'Faves', createdAt: DateTime.utc(2026)),
diff --git a/test/features/library/metadata_edit_screen_test.dart b/test/features/library/metadata_edit_screen_test.dart
index 25abe78..2908a90 100644
--- a/test/features/library/metadata_edit_screen_test.dart
+++ b/test/features/library/metadata_edit_screen_test.dart
@@ -44,6 +44,9 @@ void main() {
           mediaItemByIdProvider('x').overrideWith((ref) => _item()),
           // Finite stubs so the live Drift watch streams don't stall the test.
           tagsForItemProvider('x').overrideWith((ref) => Stream.value(<Tag>[])),
+          aiTagNamesForItemProvider(
+            'x',
+          ).overrideWith((ref) => Stream.value(<String>{})),
           collectionsProvider.overrideWith(
             (ref) => Stream.value(<Collection>[]),
           ),
@@ -85,6 +88,9 @@ void main() {
             tagsForItemProvider(
               'x',
             ).overrideWith((ref) => Stream.value(<Tag>[])),
+            aiTagNamesForItemProvider(
+              'x',
+            ).overrideWith((ref) => Stream.value(<String>{})),
             collectionsProvider.overrideWith(
               (ref) => Stream.value(<Collection>[]),
             ),
@@ -123,6 +129,9 @@ void main() {
           appDatabaseProvider.overrideWithValue(db),
           mediaItemByIdProvider('x').overrideWith((ref) => _item()),
           tagsForItemProvider('x').overrideWith((ref) => Stream.value(<Tag>[])),
+          aiTagNamesForItemProvider(
+            'x',
+          ).overrideWith((ref) => Stream.value(<String>{})),
           collectionsProvider.overrideWith(
             (ref) => Stream.value(<Collection>[]),
           ),
diff --git a/test/features/library/metadata_repository_test.dart b/test/features/library/metadata_repository_test.dart
index b9c447b..ebba96d 100644
--- a/test/features/library/metadata_repository_test.dart
+++ b/test/features/library/metadata_repository_test.dart
@@ -480,6 +480,34 @@ void main() {
     expect(meta.ocrText, isNull);
   });
 
+  test(
+    'tag provenance: watchAiTagNamesForItem returns only ai tags (P13c-2)',
+    () async {
+      await seed('a', 'Clip', 'video');
+      await repo.addTagToItem('a', 'rock', source: 'ai');
+      await repo.addTagToItem('a', 'jazz'); // default 'user'
+
+      final ai = await repo.watchAiTagNamesForItem('a').first;
+      expect(ai, {'rock'});
+    },
+  );
+
+  test(
+    'tag provenance: a user tag is not demoted when AI re-adds it (P13c-2)',
+    () async {
+      await seed('a', 'Clip', 'video');
+      await repo.addTagToItem('a', 'blues'); // user
+      await repo.addTagToItem(
+        'a',
+        'blues',
+        source: 'ai',
+      ); // insertOrIgnore → kept user
+
+      final ai = await repo.watchAiTagNamesForItem('a').first;
+      expect(ai, isEmpty);
+    },
+  );
+
   test('findItemByUrl matches with tracking params stripped (P9b-4)', () async {
     await db
         .into(db.mediaItems)
diff --git a/test/features/library/tag_suggestions_test.dart b/test/features/library/tag_suggestions_test.dart
index a21b7d1..ea3dfec 100644
--- a/test/features/library/tag_suggestions_test.dart
+++ b/test/features/library/tag_suggestions_test.dart
@@ -49,4 +49,25 @@ void main() {
       expect(parseTagSuggestions('"rock", \'live\''), ['rock', 'live']);
     });
   });
+
+  group('autoTagDecision (P13c-2)', () {
+    test('no text → skip', () {
+      expect(
+        autoTagDecision(hasText: false, modelReady: true),
+        AutoTagDecision.skip,
+      );
+    });
+    test('text + model not ready → needs model', () {
+      expect(
+        autoTagDecision(hasText: true, modelReady: false),
+        AutoTagDecision.needsModel,
+      );
+    });
+    test('text + model ready → tag', () {
+      expect(
+        autoTagDecision(hasText: true, modelReady: true),
+        AutoTagDecision.tag,
+      );
+    });
+  });
 }
diff --git a/test/features/queue/queue_controller_test.dart b/test/features/queue/queue_controller_test.dart
index 6da2efe..2506439 100644
--- a/test/features/queue/queue_controller_test.dart
+++ b/test/features/queue/queue_controller_test.dart
@@ -30,6 +30,7 @@ import 'package:grabbit/features/notifications/data/system_notification_service.
 import 'package:grabbit/features/queue/data/foreground_service.dart';
 import 'package:grabbit/features/queue/data/queue_repository.dart';
 import 'package:grabbit/features/queue/data/queued_download.dart';
+import 'package:grabbit/features/library/data/metadata_repository.dart';
 import 'package:grabbit/features/queue/presentation/queue_controller.dart';
 import 'package:grabbit/features/settings/presentation/settings_controller.dart';
 
@@ -806,6 +807,71 @@ void main() {
     expect(fakeTranscriber.transcribed, isEmpty); // no whisper on a photo
   });
 
+  // --- P13c-2: auto-tag on download ---
+
+  test(
+    'auto-tag: enabled + model ready → AI tags applied + ai entry (P13c-2)',
+    () async {
+      await container
+          .read(settingsControllerProvider.notifier)
+          .setGenerationEnabled(true);
+      await container
+          .read(settingsControllerProvider.notifier)
+          .setAutoTagOnDownload(true);
+      fakeGenerator.ready = true;
+      fakeGenerator.output = 'rock, live';
+      final dir = await describedDownload('vid1');
+
+      await controller.enqueue(
+        _qd('vid1', outputDir: dir.path, description: 'A live rock set'),
+      );
+      await waitFor(() async => engine.running.contains('vid1'));
+      engine.complete('vid1');
+      await waitFor(
+        () async => (await repo.byId('vid1'))?.status == TaskStatus.done,
+      );
+
+      // Tags applied and marked 'ai'.
+      final aiTags = await MetadataRepository(
+        db,
+      ).watchAiTagNamesForItem('vid1').first;
+      expect(aiTags, {'rock', 'live'});
+      final ai = await (db.select(
+        db.notifications,
+      )..where((n) => n.category.equals(NotificationCategory.ai))).get();
+      expect(ai, hasLength(1));
+      expect(ai.single.severity, NotificationSeverity.success);
+    },
+  );
+
+  test('auto-tag: default off → no tags, no entry (P13c-2)', () async {
+    // generationEnabled on, but autoTagOnDownload stays false.
+    await container
+        .read(settingsControllerProvider.notifier)
+        .setGenerationEnabled(true);
+    fakeGenerator.ready = true;
+    fakeGenerator.output = 'rock, live';
+    final dir = await describedDownload('vid1');
+
+    await controller.enqueue(
+      _qd('vid1', outputDir: dir.path, description: 'A live rock set'),
+    );
+    await waitFor(() async => engine.running.contains('vid1'));
+    engine.complete('vid1');
+    await waitFor(
+      () async => (await repo.byId('vid1'))?.status == TaskStatus.done,
+    );
+
+    final aiTags = await MetadataRepository(
+      db,
+    ).watchAiTagNamesForItem('vid1').first;
+    expect(aiTags, isEmpty);
+    final ai = await (db.select(
+      db.notifications,
+    )..where((n) => n.category.equals(NotificationCategory.ai))).get();
+    expect(ai, isEmpty);
+  });
+
   test('a completed download posts a success activity entry (P11c)', () async {
     final dir = await Directory.systemTemp.createTemp('grabbit_ntf_done_');
     addTearDown(() => dir.delete(recursive: true));
diff --git a/test/features/settings/settings_test.dart b/test/features/settings/settings_test.dart
index 5718639..a3cbcae 100644
--- a/test/features/settings/settings_test.dart
+++ b/test/features/settings/settings_test.dart
@@ -275,7 +275,7 @@ void main() {
     });
 
     test(
-      'auto-process setters default off and persist (P13a-2/P13b-3)',
+      'auto-process setters default off and persist (P13a-2/P13b-3/P13c-2)',
       () async {
         final db = AppDatabase(NativeDatabase.memory());
         addTearDown(db.close);
@@ -287,14 +287,17 @@ void main() {
         final loaded = await container.read(settingsControllerProvider.future);
         expect(loaded.autoSummarizeOnDownload, isFalse);
         expect(loaded.autoOcrOnDownload, isFalse);
+        expect(loaded.autoTagOnDownload, isFalse);
 
         final notifier = container.read(settingsControllerProvider.notifier);
         await notifier.setAutoSummarizeOnDownload(true);
         await notifier.setAutoOcrOnDownload(true);
+        await notifier.setAutoTagOnDownload(true);
 
         final saved = await SettingsRepository(db).read();
         expect(saved.autoSummarizeOnDownload, isTrue);
         expect(saved.autoOcrOnDownload, isTrue);
+        expect(saved.autoTagOnDownload, isTrue);
       },
     );