diff --git a/lib/cli/cli_args.dart b/lib/cli/cli_args.dart
index d40475d..1ba53f9 100644
--- a/lib/cli/cli_args.dart
+++ b/lib/cli/cli_args.dart
@@ -4,49 +4,12 @@
 /// exact-pinned dependency under the freshness gate.
 library;
 
+import 'package:todo/cli/cli_mode.dart';
 import 'package:todo/data/note.dart';
 
+export 'package:todo/cli/cli_mode.dart';
 export 'package:todo/cli/cli_usage.dart';
 
-/// What the CLI was asked to do.
-enum CliMode {
-  /// Create a note and push it.
-  add,
-
-  /// Print every live note, one per line.
-  list,
-
-  /// Print one note in full.
-  get,
-
-  /// Tombstone one note and push the deletion.
-  delete,
-
-  /// Change one note's status and push it.
-  setStatus,
-
-  /// Set a task done with evidence and push it.
-  close,
-
-  /// Print the notes matching a query, as [list] does.
-  search,
-
-  /// Print usage.
-  help,
-}
-
-/// Thrown for a malformed command line; maps to exit code 2.
-class UsageError implements Exception {
-  /// Creates a [UsageError] carrying [message].
-  UsageError(this.message);
-
-  /// What was wrong with the arguments.
-  final String message;
-
-  @override
-  String toString() => message;
-}
-
 /// The parsed command line.
 class CliArgs {
   /// Creates parsed arguments; see [parse].
@@ -58,6 +21,7 @@ class CliArgs {
     this.status,
     this.dataDir,
     this.newNote = false,
+    this.dryRun = false,
     this.opts = (
       repo: null,
       query: null,
@@ -89,6 +53,10 @@ class CliArgs {
           opts[arg] = value();
         case '--list':
           modes.add(CliMode.list);
+        case '--backfill-created-by':
+          modes.add(CliMode.backfill);
+        case '--dry-run':
+          opts[arg] = 'true';
         case '--search':
           modes.add(CliMode.search);
           opts[arg] = value();
@@ -106,8 +74,8 @@ class CliArgs {
     if (modes.contains(CliMode.help)) return const CliArgs(mode: CliMode.help);
     if (modes.length > 1) {
       throw UsageError(
-        '--list, --search, --get, --delete, --set-status and --close are '
-        'mutually exclusive',
+        '--list, --search, --get, --delete, --set-status, --close and '
+        '--backfill-created-by are mutually exclusive',
       );
     }
     final mode = modes.isEmpty ? CliMode.add : modes.single;
@@ -128,6 +96,7 @@ class CliArgs {
           opts.containsKey('--new-note') &&
           (opts['--repo'] != null ||
               (throw UsageError('--new-note needs --repo'))),
+      dryRun: opts.containsKey('--dry-run'),
       opts: (
         repo: _repo(opts['--repo']),
         query: _nonBlank(opts['--search'], '--search'),
@@ -159,6 +128,9 @@ class CliArgs {
   /// `--new-note`: the `--repo` task gets its own note.
   final bool newNote;
 
+  /// Whether `--dry-run` was given: report what would change, change nothing.
+  final bool dryRun;
+
   /// `--repo`, `--search`, `--done-check`, `--by` and `--evidence` values.
   final ({
     String? repo,
@@ -183,6 +155,7 @@ class CliArgs {
     ),
     '--evidence': ('to --close', {CliMode.close}),
     '--new-note': (_adding, {CliMode.add}),
+    '--dry-run': ('to --backfill-created-by', {CliMode.backfill}),
   };
 
   static void _checkScopes(Iterable<String> flags, CliMode mode) {
diff --git a/lib/cli/cli_commands.dart b/lib/cli/cli_commands.dart
index f0df335..a00ec68 100644
--- a/lib/cli/cli_commands.dart
+++ b/lib/cli/cli_commands.dart
@@ -38,6 +38,7 @@ class CliCommands {
       repo: repo,
       doneCheck: args.opts.doneCheck,
       by: args.opts.by,
+      createdBy: 'claude',
     );
     await session.repository.upsert(note);
     if (!await _push('note')) return 1;
@@ -57,6 +58,7 @@ class CliCommands {
       doneCheck: args.opts.doneCheck,
       priority: args.priority,
       by: args.opts.by,
+      createdBy: 'claude',
     );
     await _save(added.note);
     if (!await _push('note')) return 1;
@@ -79,6 +81,7 @@ class CliCommands {
       doneCheck: args.opts.doneCheck,
       priority: args.priority,
       by: args.opts.by,
+      createdBy: 'claude',
     );
     await _save(added.note);
     if (!await _push('note')) return 1;
@@ -142,6 +145,35 @@ class CliCommands {
     return 0;
   }
 
+  /// Sets `created_by` where unset (see [NoteRepository.backfillCreatedBy]).
+  /// Prints one `<id>\t<value>\t<title>` line per note, then the totals. With
+  /// [dryRun] nothing is written or pushed, and peers are only read.
+  Future<int> backfillCreatedBy(
+    Set<String> claudeNodes, {
+    required bool dryRun,
+  }) async {
+    _report(await session.sync(push: !dryRun));
+    final plan = await session.repository.backfillCreatedBy(
+      claudeNodes,
+      dryRun: dryRun,
+    );
+    final titles = {
+      for (final n in await session.repository.listNotes()) n.id: n,
+    };
+    for (final MapEntry(:key, :value) in plan.entries) {
+      final note = titles[key];
+      final title = note == null ? '' : note.text.split('\n').first;
+      _out.writeln(
+        '${key.substring(0, key.length.clamp(0, 8))}\t$value\t$title',
+      );
+    }
+    final claude = plan.values.where((v) => v == 'claude').length;
+    final kuhy = plan.length - claude;
+    _out.writeln('${dryRun ? 'dry run' : 'set'}: claude $claude, kuhy $kuhy');
+    if (dryRun || plan.isEmpty) return 0;
+    return await _push('backfill') ? 0 : 1;
+  }
+
   Future<Note> _pullAndFind(String ref) async {
     _report(await session.sync(push: true));
     return findNote(await session.repository.listNotes(), ref);
diff --git a/lib/cli/cli_mode.dart b/lib/cli/cli_mode.dart
new file mode 100644
index 0000000..b1671fa
--- /dev/null
+++ b/lib/cli/cli_mode.dart
@@ -0,0 +1,44 @@
+/// What the CLI can be asked to do, and how a bad command line is reported.
+library;
+
+/// What the CLI was asked to do.
+enum CliMode {
+  /// Create a note and push it.
+  add,
+
+  /// Print every live note, one per line.
+  list,
+
+  /// Print one note in full.
+  get,
+
+  /// Tombstone one note and push the deletion.
+  delete,
+
+  /// Change one note's status and push it.
+  setStatus,
+
+  /// Set a task done with evidence and push it.
+  close,
+
+  /// Print the notes matching a query, as [list] does.
+  search,
+
+  /// Set `created_by` on notes that lack it.
+  backfill,
+
+  /// Print usage.
+  help,
+}
+
+/// Thrown for a malformed command line; maps to exit code 2.
+class UsageError implements Exception {
+  /// Creates a [UsageError] carrying [message].
+  UsageError(this.message);
+
+  /// What was wrong with the arguments.
+  final String message;
+
+  @override
+  String toString() => message;
+}
diff --git a/lib/cli/cli_runner.dart b/lib/cli/cli_runner.dart
index 15c165d..d29af6f 100644
--- a/lib/cli/cli_runner.dart
+++ b/lib/cli/cli_runner.dart
@@ -80,6 +80,10 @@ Future<int> runCli(
       CliMode.get => await cli.get(args.id!),
       CliMode.setStatus => await cli.setStatus(args.id!, args.status!),
       CliMode.close => await cli.close(args.id!, args.opts.evidence!),
+      CliMode.backfill => await cli.backfillCreatedBy(
+        claudeNodeIds(env),
+        dryRun: args.dryRun,
+      ),
       // Only delete is left: help returned above.
       _ => await cli.delete(args.id!),
     };
diff --git a/lib/cli/cli_session.dart b/lib/cli/cli_session.dart
index 3c76ec9..4ecfac4 100644
--- a/lib/cli/cli_session.dart
+++ b/lib/cli/cli_session.dart
@@ -29,6 +29,19 @@ String defaultDataDir(Map<String, String> env) {
   return p.join(base, 'todo-cli');
 }
 
+/// Node ids of the installs Claude files notes through: the MCP server and
+/// the CLI under the same data root as [defaultDataDir]. Missing ones are
+/// skipped.
+Set<String> claudeNodeIds(Map<String, String> env) {
+  final cli = defaultDataDir(env);
+  return {
+    for (final dir in [cli, p.join(p.dirname(cli), 'todo-mcp')])
+      if (File(p.join(dir, CliSession.nodeIdFileName)) case final f
+          when f.existsSync())
+        f.readAsStringSync().trim(),
+  }..remove('');
+}
+
 /// The open state of one CLI invocation. Call [close] when done.
 class CliSession {
   /// Wraps already-open parts; [open] is the normal way in. Public so a test
diff --git a/lib/cli/cli_usage.dart b/lib/cli/cli_usage.dart
index 7ea303a..f02f673 100644
--- a/lib/cli/cli_usage.dart
+++ b/lib/cli/cli_usage.dart
@@ -25,6 +25,9 @@ A note with --repo is a repo task; one without is a plain idea.
   --close <id> --evidence <s>
                         pull, set status done + evidence (commit sha + done
                         check exit code), push; refused without --evidence
+  --backfill-created-by [--dry-run]
+                        pull, set created_by (claude|kuhy) on every note that
+                        has none, push; --dry-run prints the plan only
   --data-dir <dir>      local log + node id (default
                         $XDG_DATA_HOME/todo-cli or ~/.local/share/todo-cli)
   -h, --help            this text
diff --git a/lib/cli/note_lookup.dart b/lib/cli/note_lookup.dart
index 46acdf9..ce6a3ee 100644
--- a/lib/cli/note_lookup.dart
+++ b/lib/cli/note_lookup.dart
@@ -32,7 +32,7 @@ Note findNote(Iterable<Note> notes, String ref) {
   return matches.single;
 }
 
-/// `<8-char id>\t<status>\t<priority>\t<repo or ->\t<title>`.
+/// `<8-char id>\t<status>\t<priority>\t<repo or ->\t<title>\t<created_by>`.
 String listLine(Note note) => [
   if (note.id.length <= _minPrefix)
     note.id
@@ -42,6 +42,7 @@ String listLine(Note note) => [
   note.priority.name,
   note.repo ?? '-',
   _title(note),
+  note.createdBy ?? 'kuhy',
 ].join('\t');
 
 String _title(Note note) => note.text.split('\n').first;
@@ -57,6 +58,7 @@ String noteDetail(Note note) => [
   if (note.doneCheck case final v?) 'done_check: $v',
   if (note.by case final v?) 'by: $v',
   if (note.evidence case final v?) 'evidence: $v',
+  'created_by: ${note.createdBy ?? 'kuhy'}',
   '---',
   note.text,
 ].join('\n');
diff --git a/lib/data/app_settings.dart b/lib/data/app_settings.dart
index bf289d5..6802dfe 100644
--- a/lib/data/app_settings.dart
+++ b/lib/data/app_settings.dart
@@ -19,10 +19,14 @@ import 'package:shared_preferences/shared_preferences.dart';
 /// sibling to `changesets/<nodeId>.json`.
 const String kAdvancedModeRemotePath = 'settings/advancedMode';
 
-/// App-wide, non-sync preferences (currently just `advancedMode`).
+/// App-wide, non-sync preferences (`advancedMode`, `showClaudeNotes`).
 class AppSettings {
   /// Creates an [AppSettings] from its stored fields.
-  const AppSettings({required this.advancedMode, this.advancedModeUpdatedAt});
+  const AppSettings({
+    required this.advancedMode,
+    this.advancedModeUpdatedAt,
+    this.showClaudeNotes = false,
+  });
 
   /// Whether the priority/status/template/mode chrome and the routine
   /// save/sync status text are shown. Off by default: casual capture needs
@@ -35,6 +39,11 @@ class AppSettings {
   /// a value that has never round-tripped through Firebase.
   final DateTime? advancedModeUpdatedAt;
 
+  /// Whether the notes list shows notes Claude filed. Per device: it lives
+  /// only in this device's preferences and is never mirrored to Firebase.
+  final bool showClaudeNotes;
+
+  static const _kShowClaude = 'app.showClaudeNotes';
   static const _kAdvancedMode = 'app.advancedMode';
   static const _kAdvancedModeUpdatedAt = 'app.advancedMode.updatedAt';
 
@@ -44,6 +53,7 @@ class AppSettings {
     final updatedAtMillis = prefs.getInt(_kAdvancedModeUpdatedAt);
     return AppSettings(
       advancedMode: prefs.getBool(_kAdvancedMode) ?? false,
+      showClaudeNotes: prefs.getBool(_kShowClaude) ?? false,
       advancedModeUpdatedAt: updatedAtMillis == null
           ? null
           : DateTime.fromMillisecondsSinceEpoch(updatedAtMillis),
@@ -71,6 +81,7 @@ class AppSettings {
     final updated = AppSettings(
       advancedMode: value,
       advancedModeUpdatedAt: updatedAt,
+      showClaudeNotes: showClaudeNotes,
     );
     if (client != null) {
       try {
@@ -89,6 +100,17 @@ class AppSettings {
     return updated;
   }
 
+  /// Persists the per-device Claude-notes choice; nothing leaves the device.
+  Future<AppSettings> withShowClaudeNotes({required bool value}) async {
+    final prefs = await SharedPreferences.getInstance();
+    await prefs.setBool(_kShowClaude, value);
+    return AppSettings(
+      advancedMode: advancedMode,
+      advancedModeUpdatedAt: advancedModeUpdatedAt,
+      showClaudeNotes: value,
+    );
+  }
+
   /// Pulls the remote value from [client] and, if it is newer than the
   /// local one, applies it locally and returns the reconciled settings.
   /// Returns this instance unchanged when [client] is null, there is
@@ -100,9 +122,7 @@ class AppSettings {
     try {
       final remote = await client.getStringMap(kAdvancedModeRemotePath);
       if (!remote.containsKey('value')) return this;
-      final remoteUpdatedMillis = int.tryParse(
-        remote['updatedAtMillis'] ?? '',
-      );
+      final remoteUpdatedMillis = int.tryParse(remote['updatedAtMillis'] ?? '');
       if (remoteUpdatedMillis == null) return this;
       final remoteUpdatedAt = DateTime.fromMillisecondsSinceEpoch(
         remoteUpdatedMillis,
@@ -110,6 +130,7 @@ class AppSettings {
       final candidate = AppSettings(
         advancedMode: remote['value'] == 'true',
         advancedModeUpdatedAt: remoteUpdatedAt,
+        showClaudeNotes: showClaudeNotes,
       );
       final adopted = adopt(candidate);
       if (identical(adopted, this)) return this;
diff --git a/lib/data/created_by_backfill.dart b/lib/data/created_by_backfill.dart
new file mode 100644
index 0000000..8cacbd7
--- /dev/null
+++ b/lib/data/created_by_backfill.dart
@@ -0,0 +1,44 @@
+/// Who filed a note, for notes written before `created_by` existed.
+///
+/// The `created_at` field's clock names the node that last wrote it. The MCP
+/// and the CLI are the only nodes Claude writes through, so a note created
+/// there carries one of their node ids; anything else came from kuhy's own
+/// devices.
+library;
+
+import 'package:crdt_sync/crdt_sync.dart';
+import 'package:todo/data/note_record.dart';
+
+const _createdAt = 'created_at';
+
+/// `claude` when [record]'s `created_at` was written by one of [claudeNodes],
+/// else `kuhy`.
+String classifyCreatedBy(Record record, Set<String> claudeNodes) {
+  final node = record.fields[_createdAt]?.$2.nodeId;
+  return node != null && claudeNodes.contains(node) ? 'claude' : 'kuhy';
+}
+
+/// Live records of [log] with no `created_by` yet, mapped to their value.
+Map<String, String> planCreatedByBackfill(Log log, Set<String> claudeNodes) => {
+  for (final record in log.values)
+    if (!record.deleted &&
+        ((record.fields[kCreatedByField]?.$1 as String?) ?? '').isEmpty)
+      record.id: classifyCreatedBy(record, claudeNodes),
+};
+
+/// [incoming], carrying [existing]'s `created_by` when [incoming] has none.
+///
+/// A store replaces a record wholesale, so an edit that does not know the
+/// field (an import of an old backup) would otherwise drop it locally.
+Record keepCreatedBy(Record incoming, Record? existing) {
+  final kept = existing?.fields[kCreatedByField];
+  if (kept == null || incoming.fields.containsKey(kCreatedByField)) {
+    return incoming;
+  }
+  return Record(
+    id: incoming.id,
+    fields: {...incoming.fields, kCreatedByField: kept},
+    deleted: incoming.deleted,
+    deletedHlc: incoming.deletedHlc,
+  );
+}
diff --git a/lib/data/note.dart b/lib/data/note.dart
index a15969d..71452a4 100644
--- a/lib/data/note.dart
+++ b/lib/data/note.dart
@@ -76,7 +76,7 @@ enum Status {
   }
 }
 
-/// The values the optional `by` field may hold: who owns a repo task.
+/// The values the optional `by` and `created_by` fields may hold.
 const Set<String> kNoteAuthors = {'claude', 'kuhy'};
 
 /// An immutable idea/note record.
@@ -99,6 +99,7 @@ class Note {
     this.doneCheck,
     this.by,
     this.evidence,
+    this.createdBy,
   });
 
   /// Builds a [Note] from a raw CRDT query row.
@@ -146,6 +147,12 @@ class Note {
   /// Proof the task was closed (commit sha + the done check's exit code).
   final String? evidence;
 
+  /// Who filed the note: one of [kNoteAuthors]; null (older notes) means kuhy.
+  final String? createdBy;
+
+  /// Whether Claude filed this note (hidden by default, sorted last).
+  bool get isClaudeMade => createdBy == 'claude';
+
   /// Whether this note is a repo task rather than a plain idea.
   bool get isRepoTask => repo != null;
 
@@ -162,6 +169,7 @@ class Note {
     String? doneCheck,
     String? by,
     String? evidence,
+    String? createdBy,
   }) {
     return Note(
       id: id,
@@ -174,6 +182,7 @@ class Note {
       doneCheck: doneCheck ?? this.doneCheck,
       by: by ?? this.by,
       evidence: evidence ?? this.evidence,
+      createdBy: createdBy ?? this.createdBy,
     );
   }
 }
diff --git a/lib/data/note_query.dart b/lib/data/note_query.dart
index 443a897..ea40748 100644
--- a/lib/data/note_query.dart
+++ b/lib/data/note_query.dart
@@ -37,6 +37,7 @@ class NoteFilter {
     this.statuses = const {},
     this.repo,
     this.repoTasksOnly = false,
+    this.hideClaude = false,
     this.createdFrom,
     this.createdTo,
     this.updatedFrom,
@@ -58,6 +59,10 @@ class NoteFilter {
   /// Only notes that have a repo (repo tasks). Ideas are excluded.
   final bool repoTasksOnly;
 
+  /// Leave out notes Claude filed. A view preference rather than a user
+  /// facet, so it never counts toward [isEmpty] or [activeCount].
+  final bool hideClaude;
+
   /// Inclusive lower bound (by calendar day) on the creation date.
   final DateTime? createdFrom;
 
@@ -104,6 +109,7 @@ class NoteFilter {
     Set<Status>? statuses,
     String? repo,
     bool? repoTasksOnly,
+    bool? hideClaude,
     DateTime? createdFrom,
     DateTime? createdTo,
     DateTime? updatedFrom,
@@ -117,6 +123,7 @@ class NoteFilter {
       statuses: statuses ?? this.statuses,
       repo: repo ?? this.repo,
       repoTasksOnly: repoTasksOnly ?? this.repoTasksOnly,
+      hideClaude: hideClaude ?? this.hideClaude,
       createdFrom: clearCreated ? null : (createdFrom ?? this.createdFrom),
       createdTo: clearCreated ? null : (createdTo ?? this.createdTo),
       updatedFrom: clearUpdated ? null : (updatedFrom ?? this.updatedFrom),
@@ -138,6 +145,7 @@ bool matchesFilter(Note note, NoteFilter filter) {
   }
   if (filter.repo != null && note.repo != filter.repo) return false;
   if (filter.repoTasksOnly && note.repo == null) return false;
+  if (filter.hideClaude && note.isClaudeMade) return false;
   if (filter.priorities.isNotEmpty &&
       !filter.priorities.contains(note.priority)) {
     return false;
@@ -165,8 +173,17 @@ bool _withinDays(DateTime value, DateTime? from, DateTime? to) {
   return true;
 }
 
-/// The comparator implementing [sort].
+/// The comparator implementing [sort]: human-made notes first, Claude-made
+/// ones after, and [sort] orders each group.
 Comparator<Note> comparatorFor(NoteSort sort) {
+  final within = _within(sort);
+  return (a, b) {
+    if (a.isClaudeMade != b.isClaudeMade) return a.isClaudeMade ? 1 : -1;
+    return within(a, b);
+  };
+}
+
+Comparator<Note> _within(NoteSort sort) {
   switch (sort) {
     case NoteSort.createdDesc:
       return (a, b) => b.createdAt.compareTo(a.createdAt);
diff --git a/lib/data/note_record.dart b/lib/data/note_record.dart
index 0717379..34be2ff 100644
--- a/lib/data/note_record.dart
+++ b/lib/data/note_record.dart
@@ -14,6 +14,9 @@ const _doneCheck = 'done_check';
 const _by = 'by';
 const _evidence = 'evidence';
 
+/// Record field naming who filed the note (`kuhy` or `claude`).
+const kCreatedByField = 'created_by';
+
 /// Record fields for [note], all at [hlc]. Unset task fields are omitted, so
 /// an idea's record is exactly the v3 field set (and cannot clear a peer's).
 Map<String, Field> noteFields(Note note, Hlc hlc) => {
@@ -26,6 +29,7 @@ Map<String, Field> noteFields(Note note, Hlc hlc) => {
   if (note.doneCheck case final v?) _doneCheck: (v, hlc),
   if (note.by case final v?) _by: (v, hlc),
   if (note.evidence case final v?) _evidence: (v, hlc),
+  if (note.createdBy case final v?) kCreatedByField: (v, hlc),
 };
 
 /// Reads [record] as a [Note], ignoring unknown fields.
@@ -48,6 +52,7 @@ Note noteFromRecord(Record record) {
     doneCheck: task(_doneCheck),
     by: task(_by),
     evidence: task(_evidence),
+    createdBy: task(kCreatedByField),
   );
 }
 
diff --git a/lib/data/note_repository.dart b/lib/data/note_repository.dart
index 42afff5..aa27015 100644
--- a/lib/data/note_repository.dart
+++ b/lib/data/note_repository.dart
@@ -1,6 +1,7 @@
 import 'dart:async';
 
 import 'package:crdt_sync/crdt_sync.dart';
+import 'package:todo/data/created_by_backfill.dart';
 import 'package:todo/data/note.dart';
 import 'package:todo/data/note_import.dart';
 import 'package:todo/data/note_query.dart';
@@ -114,9 +115,32 @@ class NoteRepository {
   /// character-by-character autosave: it is cheap and idempotent. All fields
   /// share one fresh monotonic clock (they are written together).
   Future<void> upsert(Note note) async {
-    await _store.upsert(
-      Record(id: note.id, fields: noteFields(note, _store.nextHlc())),
+    await _put(Record(id: note.id, fields: noteFields(note, _store.nextHlc())));
+  }
+
+  Future<void> _put(Record record) =>
+      _store.upsert(keepCreatedBy(record, _store.get(record.id)));
+
+  /// Sets `created_by` on every live note that has none, from the node that
+  /// wrote its `created_at` (see [classifyCreatedBy]); returns id -> value.
+  ///
+  /// Writes only that field, at a fresh clock, so no other field's clock
+  /// moves (a rewrite of `created_at` would erase the signal itself). With
+  /// [dryRun] nothing is written.
+  Future<Map<String, String>> backfillCreatedBy(
+    Set<String> claudeNodes, {
+    bool dryRun = false,
+  }) async {
+    final plan = planCreatedByBackfill(_store.snapshot(), claudeNodes);
+    if (dryRun || plan.isEmpty) return plan;
+    final hlc = _store.nextHlc();
+    await _store.replaceAll(
+      mergeLogs(_store.snapshot(), {
+        for (final e in plan.entries)
+          e.key: Record(id: e.key, fields: {kCreatedByField: (e.value, hlc)}),
+      }),
     );
+    return plan;
   }
 
   /// Soft-deletes a note. The log keeps a sticky tombstone so the deletion
@@ -142,10 +166,10 @@ class NoteRepository {
       // the import wins locally; the clock decides whether it wins on *other*
       // devices, and an import must not win there simply by being recent.
       if (local == null) {
-        await _store.upsert(recordAtNoteTime(note, _nodeId));
+        await _put(recordAtNoteTime(note, _nodeId));
         added++;
       } else if (note.updatedAt.isAfter(local.updatedAt)) {
-        await _store.upsert(recordAtNoteTime(note, _nodeId));
+        await _put(recordAtNoteTime(note, _nodeId));
         updated++;
       } else {
         skipped++;
diff --git a/lib/data/repo_note.dart b/lib/data/repo_note.dart
index 2271542..5987f77 100644
--- a/lib/data/repo_note.dart
+++ b/lib/data/repo_note.dart
@@ -71,6 +71,7 @@ Future<RepoAdd> addRepoTask(
   String? doneCheck,
   Priority priority = Priority.medium,
   String? by,
+  String? createdBy,
 }) async {
   final section = repoSection(title, body);
   final open = (await repository.listNotes(
@@ -99,6 +100,7 @@ Future<RepoAdd> addRepoTask(
       repo: repo,
       doneCheck: composeDoneCheck(null, doneCheck),
       by: by,
+      createdBy: createdBy,
     ),
     appended: false,
   );
diff --git a/lib/data/repo_note_split.dart b/lib/data/repo_note_split.dart
index f45b13e..4aa03be 100644
--- a/lib/data/repo_note_split.dart
+++ b/lib/data/repo_note_split.dart
@@ -77,6 +77,7 @@ Future<SplitAdd> addSeparateTask(
   String? doneCheck,
   Priority priority = Priority.medium,
   String? by,
+  String? createdBy,
   Future<bool> Function(Note note)? busy,
 }) async {
   final section = repoSection(title, body);
@@ -113,6 +114,7 @@ Future<SplitAdd> addSeparateTask(
       repo: repo,
       doneCheck: composeDoneCheck(null, doneCheck),
       by: by,
+      createdBy: createdBy,
     ),
     kind: why == null ? SplitKind.added : SplitKind.fellBack,
     why: why,
diff --git a/lib/mcp/task_service.dart b/lib/mcp/task_service.dart
index 8f23e0f..68292f7 100644
--- a/lib/mcp/task_service.dart
+++ b/lib/mcp/task_service.dart
@@ -76,6 +76,7 @@ class TaskService {
       doneCheck: a.optional('done_check'),
       priority: a.priority() ?? Priority.medium,
       by: 'claude',
+      createdBy: 'claude',
     );
     final verb = added.appended ? 'appended to' : 'added';
     return (reply: await _save(added.note, verb), start: null);
diff --git a/lib/mcp/task_split.dart b/lib/mcp/task_split.dart
index 9cfef54..d7a14f5 100644
--- a/lib/mcp/task_split.dart
+++ b/lib/mcp/task_split.dart
@@ -35,6 +35,7 @@ Future<SplitReply> addSplit(
     doneCheck: doneCheck,
     priority: priority,
     by: 'claude',
+    createdBy: 'claude',
     busy: board == null ? null : (n) => board.running(n.id),
   );
   if (added.kind != SplitKind.merged) {
diff --git a/lib/mcp/todo_mcp_server.dart b/lib/mcp/todo_mcp_server.dart
index 6101fa5..6e9a6d5 100644
--- a/lib/mcp/todo_mcp_server.dart
+++ b/lib/mcp/todo_mcp_server.dart
@@ -116,7 +116,8 @@ McpServer _server(TaskService tasks) {
   tool(
     'list_tasks',
     'List repo tasks, one line each: 8-char id, status, priority, repo, '
-        'title. Default status "open" (todo + in_progress).',
+        'title, created_by (kuhy|claude). Default status "open" '
+        '(todo + in_progress).',
     {
       'repo': repo,
       'status': JsonSchema.string(
diff --git a/lib/sync/notes_markdown.dart b/lib/sync/notes_markdown.dart
index 76d4a65..5f27265 100644
--- a/lib/sync/notes_markdown.dart
+++ b/lib/sync/notes_markdown.dart
@@ -92,6 +92,7 @@ class NotesMarkdown {
           doneCheck: attrs['done_check'],
           by: attrs['by'],
           evidence: attrs['evidence'],
+          createdBy: attrs['created_by'],
         ),
       );
     }
@@ -113,6 +114,7 @@ class NotesMarkdown {
       ('done_check', note.doneCheck),
       ('by', note.by),
       ('evidence', note.evidence),
+      ('created_by', note.createdBy),
     ])
       if (value != null) ' $name="${_escape(value)}"',
   ].join();
diff --git a/lib/ui/capture_draft.dart b/lib/ui/capture_draft.dart
index 7b30262..b381d2a 100644
--- a/lib/ui/capture_draft.dart
+++ b/lib/ui/capture_draft.dart
@@ -102,6 +102,7 @@ class CaptureDraft {
         status: status,
         createdAt: _createdAt!,
         updatedAt: now,
+        createdBy: 'kuhy',
       ),
     );
     if (live()) lastSavedAt.value = now;
diff --git a/lib/ui/notes_list_screen.dart b/lib/ui/notes_list_screen.dart
index e22318c..4565629 100644
--- a/lib/ui/notes_list_screen.dart
+++ b/lib/ui/notes_list_screen.dart
@@ -56,7 +56,7 @@ class _NotesListScreenState extends State<NotesListScreen> {
   @override
   void initState() {
     super.initState();
-    _stream = widget.repository.watchNotes(sort: _sort, filter: _filter);
+    _stream = _watch();
   }
 
   @override
@@ -69,9 +69,26 @@ class _NotesListScreenState extends State<NotesListScreen> {
   /// Rebuilds the watch stream for the current sort + filter. Call only
   /// from handlers that change those, never from [build].
   void _applyState() {
-    setState(() {
-      _stream = widget.repository.watchNotes(sort: _sort, filter: _filter);
-    });
+    setState(() => _stream = _watch());
+  }
+
+  /// The query for the current sort + filter, minus Claude-made notes unless
+  /// this device's eye toggle is on.
+  Stream<List<Note>> _watch() => widget.repository.watchNotes(
+    sort: _sort,
+    filter: _filter.copyWith(
+      hideClaude: !widget.appSettings.value.showClaudeNotes,
+    ),
+  );
+
+  Future<void> _toggleClaudeNotes() async {
+    final settings = widget.appSettings.value;
+    final next = await settings.withShowClaudeNotes(
+      value: !settings.showClaudeNotes,
+    );
+    if (!mounted) return;
+    widget.appSettings.value = next;
+    _applyState();
   }
 
   void _onSearchChanged(String value) {
@@ -110,6 +127,16 @@ class _NotesListScreenState extends State<NotesListScreen> {
       appBar: AppBar(
         title: const Text('Notes'),
         actions: [
+          // Eye, no label: open = Claude-made notes shown, slashed = hidden.
+          IconButton(
+            icon: Icon(
+              widget.appSettings.value.showClaudeNotes
+                  ? Icons.visibility
+                  : Icons.visibility_off,
+              semanticLabel: 'Claude notes',
+            ),
+            onPressed: _toggleClaudeNotes,
+          ),
           PopupMenuButton<NoteSort>(
             tooltip: 'Sort',
             icon: const Icon(Icons.sort),
diff --git a/mcp/README.md b/mcp/README.md
index 58bd20a..f409016 100644
--- a/mcp/README.md
+++ b/mcp/README.md
@@ -10,6 +10,12 @@ The server is one more sync node: it reuses `lib/cli` (`CliSession`,
 `todo-sync/notes/<node id>.json` plus `todo-sync/revs/<node id>`.
 Code: `lib/mcp/`, entrypoint `mcp/todo_mcp.dart`, tests `test/mcp/`.
 
+Output shapes: `list_tasks` and `search_tasks` print one tab-separated line per
+task (`id8 status priority repo title created_by`); `get_task` prints
+`key: value` lines (including `created_by`) then `---` and the text.
+`created_by` is `claude` for notes filed through `add_task` or the CLI and
+`kuhy` for everything else (a missing value reads as `kuhy`).
+
 | What | Where |
 |---|---|
 | Firebase seed (read once) | `~/.config/todo-mcp/firebase_auth.json` |
diff --git a/pubspec.yaml b/pubspec.yaml
index 2838e2e..0122543 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -16,7 +16,7 @@ publish_to: 'none' # Remove this line if you wish to publish to pub.dev
 # https://developer.apple.com/library/archive/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html
 # In Windows, build-name is used as the major, minor, and patch parts
 # of the product and file versions while build-number is used as the build suffix.
-version: 1.0.65+1
+version: 1.0.66+1
 
 environment:
   sdk: ^3.12.2
diff --git a/test/capture_screen_created_by_test.dart b/test/capture_screen_created_by_test.dart
new file mode 100644
index 0000000..0b6a286
--- /dev/null
+++ b/test/capture_screen_created_by_test.dart
@@ -0,0 +1,21 @@
+// A note typed into the app is stamped created_by kuhy.
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+import 'capture_screen_harness.dart';
+
+void main() {
+  testWidgets('a captured note is stamped kuhy and keeps it on edit', (
+    tester,
+  ) async {
+    final repo = await pumpCapture(tester);
+    await tester.enterText(find.byType(TextField).first, 'First line');
+    await tester.pump();
+    await tester.enterText(find.byType(TextField).first, 'First line, more');
+    await tester.pump();
+
+    final saved = (await repo.listNotes()).single;
+    expect(saved.text, 'First line, more');
+    expect(saved.createdBy, 'kuhy');
+  });
+}
diff --git a/test/cli/cli_created_by_test.dart b/test/cli/cli_created_by_test.dart
new file mode 100644
index 0000000..9e36406
--- /dev/null
+++ b/test/cli/cli_created_by_test.dart
@@ -0,0 +1,85 @@
+// created_by through the CLI: stamping, output, and the backfill command.
+import 'dart:io';
+
+import 'package:flutter_test/flutter_test.dart';
+
+import 'cli_harness.dart';
+
+void main() {
+  late CliHarness h;
+  setUp(() => h = CliHarness());
+  tearDown(() => h.dispose());
+
+  test('a CLI add is stamped claude, repo task or idea', () async {
+    final idea = await h.add('Plain idea');
+    final task = await h.add('Fix gate', ['--repo', 'kuhyx/todo']);
+    for (final id in [idea, task]) {
+      expect(await h.run(['--get', id, '--data-dir', h.dir('b')]), 0);
+      expect(h.out.toString(), contains('created_by: claude'));
+    }
+    expect(await h.run(['--list']), 0);
+    expect(
+      h.out.toString().trim().split('\n'),
+      everyElement(endsWith('\tclaude')),
+    );
+  });
+
+  test('a --new-note add is stamped claude', () async {
+    final id = await h.add('Own note', ['--repo', 'kuhyx/todo', '--new-note']);
+    expect(await h.run(['--get', id, '--data-dir', h.dir('b')]), 0);
+    expect(h.out.toString(), contains('created_by: claude'));
+  });
+
+  test('a peer note without created_by reads as kuhy', () async {
+    h.seedPeer([fixtureNote('peer-note-1', 'From the phone')]);
+    expect(await h.run(['--get', 'peer-note-1']), 0);
+    expect(h.out.toString(), contains('created_by: kuhy'));
+    expect(await h.run(['--list']), 0);
+    expect(h.out.toString(), endsWith('From the phone\tkuhy\n'));
+  });
+
+  group('--backfill-created-by', () {
+    void seed() {
+      final mcp = Directory('${h.env['XDG_DATA_HOME']}/todo-mcp')
+        ..createSync(recursive: true);
+      File('${mcp.path}/node_id').writeAsStringSync('mcp-node\n');
+      h.seedPeer([
+        fixtureNote('mcp-note-0001', 'Make a text-free', repo: 'kuhyx/a'),
+      ], node: 'mcp-node');
+      h.seedPeer([fixtureNote('idea-note-0001', 'My idea')], node: 'phone');
+    }
+
+    test('--dry-run lists the plan and writes nothing', () async {
+      seed();
+      expect(await h.run(['--backfill-created-by', '--dry-run']), 0);
+      final lines = h.out.toString().trim().split('\n');
+      expect(lines, contains('mcp-note\tclaude\tMake a text-free'));
+      expect(lines, contains('idea-not\tkuhy\tMy idea'));
+      expect(lines.last, 'dry run: claude 1, kuhy 1');
+      expect(h.db.methods, isNot(contains('PUT')), reason: 'nothing pushed');
+    });
+
+    test('a real run sets it once, pushes it, and is then a no-op', () async {
+      seed();
+      expect(await h.run(['--backfill-created-by']), 0);
+      expect(h.out.toString().trim().split('\n').last, 'set: claude 1, kuhy 1');
+      expect(
+        await h.run(['--get', 'mcp-note-0001', '--data-dir', h.dir('b')]),
+        0,
+      );
+      expect(h.out.toString(), contains('created_by: claude'));
+      expect(
+        await h.run(['--get', 'idea-note-0001', '--data-dir', h.dir('b')]),
+        0,
+      );
+      expect(h.out.toString(), contains('created_by: kuhy'));
+      expect(await h.run(['--backfill-created-by']), 0);
+      expect(h.out.toString().trim(), 'set: claude 0, kuhy 0');
+    });
+
+    test('--dry-run is refused without the backfill flag', () async {
+      expect(await h.run(['--dry-run']), 2);
+      expect(h.err.toString(), contains('--dry-run only applies'));
+    });
+  });
+}
diff --git a/test/cli/cli_harness.dart b/test/cli/cli_harness.dart
index 1a47e2b..aa9d1c2 100644
--- a/test/cli/cli_harness.dart
+++ b/test/cli/cli_harness.dart
@@ -60,10 +60,10 @@ class CliHarness {
     return out.toString().trim();
   }
 
-  /// Publishes [notes] as another device's log.
-  void seedPeer(List<Note> notes) {
-    db.files['todo-sync/notes/peer~2Ejson'] = logToJson({
-      for (final n in notes) n.id: NoteRepository.recordAtNoteTime(n, 'peer'),
+  /// Publishes [notes] as device [node]'s log.
+  void seedPeer(List<Note> notes, {String node = 'peer'}) {
+    db.files['todo-sync/notes/$node~2Ejson'] = logToJson({
+      for (final n in notes) n.id: NoteRepository.recordAtNoteTime(n, node),
     });
   }
 }
diff --git a/test/cli/cli_runner_test.dart b/test/cli/cli_runner_test.dart
index 410d84f..b5bce38 100644
--- a/test/cli/cli_runner_test.dart
+++ b/test/cli/cli_runner_test.dart
@@ -121,7 +121,7 @@ void main() {
       expect(await run(['--list', '--data-dir', dir('b')]), 0);
       expect(
         out.toString().trim(),
-        '${id.substring(0, 8)}\tin_progress\thigh\t-\tTitle',
+        '${id.substring(0, 8)}\tin_progress\thigh\t-\tTitle\tclaude',
       );
 
       expect(await run(['--get', id, '--data-dir', dir('b')]), 0);
diff --git a/test/cli/cli_tasks_test.dart b/test/cli/cli_tasks_test.dart
index 7b7d3cb..f6c74eb 100644
--- a/test/cli/cli_tasks_test.dart
+++ b/test/cli/cli_tasks_test.dart
@@ -41,7 +41,7 @@ void main() {
     expect(await h.run(['--list', '--repo', 'kuhyx/todo']), 0);
     expect(
       h.out.toString(),
-      '${todo.substring(0, 8)}\ttodo\tmedium\tkuhyx/todo\ttodo todos\n',
+      '${todo.substring(0, 8)}\ttodo\tmedium\tkuhyx/todo\ttodo todos\tclaude\n',
     );
     expect(await h.run(['--list', '--status', 'done']), 0);
     expect(h.out.toString(), isEmpty);
diff --git a/test/cli/note_lookup_test.dart b/test/cli/note_lookup_test.dart
index 72cbcaf..7a46f70 100644
--- a/test/cli/note_lookup_test.dart
+++ b/test/cli/note_lookup_test.dart
@@ -65,12 +65,15 @@ void main() {
     );
   });
 
-  test('listLine: 8-char id, status, priority, repo, title', () {
+  test('listLine: 8-char id, status, priority, repo, title, author', () {
     expect(
       listLine(notes[2].copyWith(status: Status.inProgress)),
-      '12345678\tin_progress\tmedium\t-\tFirst',
+      '12345678\tin_progress\tmedium\t-\tFirst\tkuhy',
+    );
+    expect(
+      listLine(notes[4]),
+      '99999999\ttodo\tmedium\tkuhyx/todo\tOnly\tkuhy',
     );
-    expect(listLine(notes[4]), '99999999\ttodo\tmedium\tkuhyx/todo\tOnly');
     expect(listLine(fixtureNote('abc', 'Short')), startsWith('abc\t'));
   });
 }
diff --git a/test/fake_note_repository.dart b/test/fake_note_repository.dart
index 0b902e9..20b27ce 100644
--- a/test/fake_note_repository.dart
+++ b/test/fake_note_repository.dart
@@ -104,6 +104,12 @@ class FakeNoteRepository implements NoteRepository {
   @override
   Stream<int> watchCount() => _snapshots().map((n) => n.length);
 
+  @override
+  Future<Map<String, String>> backfillCreatedBy(
+    Set<String> claudeNodes, {
+    bool dryRun = false,
+  }) async => {};
+
   @override
   String get nodeId => 'fake-node';
 
diff --git a/test/mcp/mcp_created_by_test.dart b/test/mcp/mcp_created_by_test.dart
new file mode 100644
index 0000000..037e5cb
--- /dev/null
+++ b/test/mcp/mcp_created_by_test.dart
@@ -0,0 +1,88 @@
+// add_task stamps created_by claude; every read tool reports it.
+import 'package:flutter_test/flutter_test.dart';
+import 'package:mcp_dart/mcp_dart.dart';
+import 'package:todo/data/note.dart';
+
+import 'mcp_harness.dart';
+
+void main() {
+  late McpHarness h;
+  late McpClient c;
+  setUp(() async {
+    h = McpHarness();
+    await h.start();
+    c = await h.connect();
+  });
+  tearDown(() => h.dispose());
+
+  test('add_task is stamped claude and list/get/search show it', () async {
+    final added = await h.call(c, 'add_task', {
+      'repo': 'kuhyx/todo',
+      'title': 'Fix gate',
+    });
+    final id = idIn(added);
+    final stored = (await h.session.repository.listNotes()).single;
+    expect(stored.createdBy, 'claude');
+
+    expect(
+      await h.call(c, 'get_task', {'id': id}),
+      contains('created_by: claude'),
+    );
+    for (final listed in [
+      await h.call(c, 'list_tasks', {}),
+      await h.call(c, 'search_tasks', {'query': 'gate'}),
+    ]) {
+      expect(listed.trim(), endsWith('\tclaude'));
+    }
+  });
+
+  test('a separate new_note task is stamped claude too', () async {
+    await h.call(c, 'add_task', {
+      'repo': 'kuhyx/todo',
+      'title': 'Own note',
+      'new_note': true,
+    });
+    expect((await h.session.repository.listNotes()).single.createdBy, 'claude');
+  });
+
+  test('a record without created_by reads as kuhy', () async {
+    final at = DateTime.utc(2026, 11);
+    await h.session.repository.upsert(
+      Note(
+        id: 'human-task-0001',
+        text: 'Human task',
+        priority: Priority.medium,
+        status: Status.todo,
+        createdAt: at,
+        updatedAt: at,
+        repo: 'kuhyx/todo',
+      ),
+    );
+    expect(
+      await h.call(c, 'get_task', {'id': 'human-task-0001'}),
+      contains('created_by: kuhy'),
+    );
+    expect(
+      (await h.call(c, 'list_tasks', {})).trim(),
+      endsWith('Human task\tkuhy'),
+    );
+  });
+
+  test('joining a human-made repo note keeps its author', () async {
+    final at = DateTime.utc(2026, 11);
+    await h.session.repository.upsert(
+      Note(
+        id: 'human-task-0001',
+        text: 'todo todos',
+        priority: Priority.medium,
+        status: Status.todo,
+        createdAt: at,
+        updatedAt: at,
+        repo: 'kuhyx/todo',
+        createdBy: 'kuhy',
+      ),
+    );
+    await h.call(c, 'add_task', {'repo': 'kuhyx/todo', 'title': 'More'});
+    expect((await h.session.repository.listNotes()).single.createdBy, 'kuhy');
+  });
+}
diff --git a/test/note_created_by_test.dart b/test/note_created_by_test.dart
new file mode 100644
index 0000000..e0d92b2
--- /dev/null
+++ b/test/note_created_by_test.dart
@@ -0,0 +1,181 @@
+// created_by: record mapping, merge safety against older builds, list order,
+// the hide filter and backfill classification.
+import 'package:crdt_sync/crdt_sync.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:todo/data/created_by_backfill.dart';
+import 'package:todo/data/note.dart';
+import 'package:todo/data/note_repository.dart';
+
+Note _note(
+  String id, {
+  String? createdBy,
+  Priority priority = Priority.medium,
+  DateTime? updated,
+}) {
+  final at = updated ?? DateTime.utc(2026, 11);
+  return Note(
+    id: id,
+    text: 'note $id',
+    priority: priority,
+    status: Status.todo,
+    createdAt: at,
+    updatedAt: at,
+    createdBy: createdBy,
+  );
+}
+
+/// What an older build writes: no created_by, replacing the record locally.
+Map<String, Field> _oldFields(Note n, Hlc hlc) => {
+  'text': (n.text, hlc),
+  'priority': (n.priority.value, hlc),
+  'status': (n.status.value, hlc),
+  'created_at': (n.createdAt.toIso8601String(), hlc),
+  'updated_at': (n.updatedAt.toIso8601String(), hlc),
+};
+
+Log _overTheWire(Log log) => logFromJson(logToJson(log));
+
+void main() {
+  group('record mapping', () {
+    test('created_by is written only when set and read back', () {
+      final hlc = Hlc(wallTimeMs: 1, counter: 0, nodeId: 'n');
+      expect(
+        noteFields(_note('a'), hlc).containsKey('created_by'),
+        isFalse,
+        reason: 'an unset field keeps the record wire-identical',
+      );
+      final fields = noteFields(_note('a', createdBy: 'claude'), hlc);
+      expect(fields['created_by']!.$1, 'claude');
+      final back = noteFromRecord(Record(id: 'a', fields: fields));
+      expect(back.createdBy, 'claude');
+      expect(back.isClaudeMade, isTrue);
+      expect(_note('b', createdBy: 'kuhy').isClaudeMade, isFalse);
+      expect(_note('c').isClaudeMade, isFalse);
+    });
+
+    test('copyWith keeps createdBy unless replaced', () {
+      final n = _note('a', createdBy: 'claude');
+      expect(n.copyWith(text: 'x').createdBy, 'claude');
+      expect(n.copyWith(createdBy: 'kuhy').createdBy, 'kuhy');
+    });
+  });
+
+  group('merge safety', () {
+    test(
+      'an older build upsert (no created_by) does not wipe a peer value',
+      () async {
+        final current = await NoteRepository.openInMemory(nodeId: 'new');
+        await current.upsert(_note('a', createdBy: 'claude'));
+
+        final old = LogStore(persistence: MemoryPersistence(), nodeId: 'old');
+        await old.load();
+        await old.replaceAll(
+          mergeLogs(old.snapshot(), _overTheWire(current.exportLog())),
+        );
+        final edited = _note('a', updated: DateTime.utc(2026, 11, 2));
+        await old.upsert(
+          Record(id: 'a', fields: _oldFields(edited, old.nextHlc())),
+        );
+        expect(old.snapshot()['a']!.fields.containsKey('created_by'), isFalse);
+
+        await current.importLog(_overTheWire(old.snapshot()));
+        expect((await current.listNotes()).single.createdBy, 'claude');
+
+        // Pulling the other way restores it on the older device too.
+        await old.replaceAll(
+          mergeLogs(old.snapshot(), _overTheWire(current.exportLog())),
+        );
+        expect(old.snapshot()['a']!.fields['created_by']!.$1, 'claude');
+      },
+    );
+
+    test('upserting a note without createdBy keeps the stored value', () async {
+      final repo = await NoteRepository.openInMemory();
+      await repo.upsert(_note('a', createdBy: 'claude'));
+      await repo.upsert(_note('a', updated: DateTime.utc(2026, 11, 3)));
+      expect((await repo.listNotes()).single.createdBy, 'claude');
+      await repo.importNotes([_note('a', updated: DateTime.utc(2027))]);
+      expect((await repo.listNotes()).single.createdBy, 'claude');
+    });
+  });
+
+  group('order and hiding', () {
+    final claudeHigh = _note('c', createdBy: 'claude', priority: Priority.high);
+    final humanLow = _note('h', createdBy: 'kuhy', priority: Priority.low);
+    final legacy = _note('l', priority: Priority.medium);
+
+    test(
+      'human notes come first under every sort, then the old order',
+      () async {
+        final repo = await NoteRepository.openInMemory();
+        for (final n in [claudeHigh, humanLow, legacy]) {
+          await repo.upsert(n);
+        }
+        for (final sort in NoteSort.values) {
+          final ids = [for (final n in await repo.listNotes(sort: sort)) n.id];
+          expect(ids.last, 'c', reason: '$sort');
+        }
+        final byPriority = await repo.listNotes();
+        expect([for (final n in byPriority) n.id], ['l', 'h', 'c']);
+      },
+    );
+
+    test('hideClaude drops Claude-made notes and is not a user facet', () {
+      const filter = NoteFilter(hideClaude: true);
+      expect(matchesFilter(claudeHigh, filter), isFalse);
+      expect(matchesFilter(humanLow, filter), isTrue);
+      expect(matchesFilter(legacy, filter), isTrue);
+      expect(matchesFilter(claudeHigh, const NoteFilter()), isTrue);
+      expect(filter.isEmpty, isTrue);
+      expect(filter.activeCount, 0);
+      expect(filter.copyWith(query: 'x').hideClaude, isTrue);
+      expect(filter.copyWith(hideClaude: false).hideClaude, isFalse);
+    });
+  });
+
+  group('backfill', () {
+    Record rec(String id, String node, {String? createdBy, bool dead = false}) {
+      final hlc = Hlc(wallTimeMs: 5, counter: 0, nodeId: node);
+      return Record(
+        id: id,
+        fields: {...noteFields(_note(id, createdBy: createdBy), hlc)},
+        deleted: dead,
+        deletedHlc: dead ? hlc : null,
+      );
+    }
+
+    test('classifies by the node that wrote created_at', () {
+      const claude = {'mcp', 'cli'};
+      expect(classifyCreatedBy(rec('a', 'mcp'), claude), 'claude');
+      expect(classifyCreatedBy(rec('a', 'cli'), claude), 'claude');
+      expect(classifyCreatedBy(rec('a', 'phone'), claude), 'kuhy');
+      const bare = Record(id: 'x', fields: {});
+      expect(classifyCreatedBy(bare, claude), 'kuhy');
+    });
+
+    test('writes only unset, live records, and only that field', () async {
+      final repo = await NoteRepository.openInMemory(nodeId: 'cli');
+      await repo.importLog({
+        'a': rec('a', 'mcp'),
+        'b': rec('b', 'phone'),
+        'c': rec('c', 'phone', createdBy: 'claude'),
+        'd': rec('d', 'mcp', dead: true),
+      });
+      const claude = {'mcp', 'cli'};
+      final dry = await repo.backfillCreatedBy(claude, dryRun: true);
+      expect(dry, {'a': 'claude', 'b': 'kuhy'});
+      expect(repo.exportLog()['a']!.fields.containsKey('created_by'), isFalse);
+
+      final done = await repo.backfillCreatedBy(claude);
+      expect(done, dry);
+      final log = repo.exportLog();
+      expect(log['a']!.fields['created_by']!.$1, 'claude');
+      expect(log['b']!.fields['created_by']!.$1, 'kuhy');
+      expect(log['c']!.fields['created_by']!.$1, 'claude');
+      expect(log['d']!.fields.containsKey('created_by'), isFalse);
+      // created_at keeps its original clock: the signal is not destroyed.
+      expect(log['b']!.fields['created_at']!.$2.nodeId, 'phone');
+      expect(await repo.backfillCreatedBy(claude), isEmpty);
+    });
+  });
+}
diff --git a/test/notes_list_claude_toggle_test.dart b/test/notes_list_claude_toggle_test.dart
new file mode 100644
index 0000000..351f327
--- /dev/null
+++ b/test/notes_list_claude_toggle_test.dart
@@ -0,0 +1,100 @@
+// Claude-made notes: hidden by default, an eye toggle shows them, the choice
+// is remembered per device, and human notes always sort first.
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+import 'package:todo/data/app_settings.dart';
+import 'package:todo/data/note.dart';
+import 'package:todo/ui/notes_list_screen.dart';
+
+import 'fake_note_repository.dart';
+import 'notes_list_harness.dart';
+
+final _seed = [
+  note(
+    'c',
+    'Claude chore',
+    priority: Priority.high,
+  ).copyWith(createdBy: 'claude'),
+  note('h', 'Human idea', priority: Priority.low).copyWith(createdBy: 'kuhy'),
+  note('l', 'Legacy idea'),
+];
+
+Future<ValueNotifier<AppSettings>> _pump(
+  WidgetTester tester, {
+  AppSettings settings = const AppSettings(advancedMode: true),
+}) async {
+  final repo = FakeNoteRepository(_seed, true);
+  addTearDown(repo.close);
+  final notifier = ValueNotifier(settings);
+  addTearDown(notifier.dispose);
+  await tester.pumpWidget(
+    MaterialApp(
+      home: NotesListScreen(repository: repo, appSettings: notifier),
+    ),
+  );
+  await tester.pump();
+  return notifier;
+}
+
+Future<void> _tap(WidgetTester tester, IconData icon) async {
+  await tester.tap(find.byIcon(icon));
+  await tester.pump();
+  await tester.pump();
+}
+
+void main() {
+  setUp(() => SharedPreferences.setMockInitialValues({}));
+
+  testWidgets('Claude-made notes are hidden until the eye is tapped', (
+    tester,
+  ) async {
+    await _pump(tester);
+    expect(find.text('Claude chore'), findsNothing);
+    expect(find.text('Human idea'), findsOneWidget);
+    expect(find.text('Legacy idea'), findsOneWidget);
+    expect(find.byIcon(Icons.visibility_off), findsOneWidget);
+
+    await _tap(tester, Icons.visibility_off);
+    expect(find.text('Claude chore'), findsOneWidget);
+    expect(find.byIcon(Icons.visibility), findsOneWidget);
+
+    await _tap(tester, Icons.visibility);
+    expect(find.text('Claude chore'), findsNothing);
+  });
+
+  testWidgets('shown, Claude notes sort below every human note', (
+    tester,
+  ) async {
+    await _pump(
+      tester,
+      settings: const AppSettings(advancedMode: true, showClaudeNotes: true),
+    );
+    double y(String t) => tester.getTopLeft(find.text(t)).dy;
+    // The default 800x600 view lists one note per row, in display order; the
+    // high-priority Claude note still comes last.
+    expect(y('Claude chore'), greaterThan(y('Human idea')));
+    expect(y('Claude chore'), greaterThan(y('Legacy idea')));
+  });
+
+  testWidgets('the choice is persisted per device and reloaded', (
+    tester,
+  ) async {
+    final notifier = await _pump(tester);
+    await _tap(tester, Icons.visibility_off);
+    expect(notifier.value.showClaudeNotes, isTrue);
+    final prefs = await SharedPreferences.getInstance();
+    expect(prefs.getBool('app.showClaudeNotes'), isTrue);
+    expect((await AppSettings.load()).showClaudeNotes, isTrue);
+  });
+
+  test('advancedMode and the toggle do not overwrite each other', () async {
+    final shown = await const AppSettings(
+      advancedMode: false,
+    ).withShowClaudeNotes(value: true);
+    expect(shown.advancedMode, isFalse);
+    final both = await shown.withAdvancedMode(value: true);
+    expect(both.showClaudeNotes, isTrue);
+    expect(both.advancedMode, isTrue);
+  });
+}