replay-latest ValueStream for session state streams (T-386, T-274)

Broadcast streams drop the current value for late subscribers — the
shape behind T-274: the init event fires while spawn() is still
awaiting the transcript-tail read, before the pane subscribes, so the
status bar stayed blank. New pure-Dart ValueStream<T> (no rxdart —
prefer-zero-deps) replays the latest value to each new subscriber;
statusStream, busyStream, and pendingPromptStream in the claude
builtin now use it. busyStream subscribers see the current state
first (seeded false), which the busy test now asserts.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

.pql/changelog/ticket_history/2026-06.sql

@@ -3994,3 +3994,6 @@ UPDATE 2026-06-08: the active hang did NOT reproduce — clide is running fine i
 T-361 (done, 2026-06-12) added the session-level building blocks this ticket can reuse: StreamJsonSession now watches the process exit code (SessionEnd with stderr tail, replay-latest via session.end) and the pane surfaces ''claude exited (code N) — /clear to restart''. A resume that dies at spawn now surfaces instead of hanging silently; what remains here is the timeout/fallback for a resume that starts but never produces the init event, and resume-decided-by-content.', NULL, '2026-06-11 22:53:52', '2026-06-11 22:53:52', '2026-06-11 22:53:52', NULL, '5a99913696126412ccc7b18f75d3ec15', 2) ON CONFLICT(hash) DO NOTHING;
 INSERT INTO ticket_history (ticket_record_id, field, old_value, new_value, changed_by, changed_at, created_at, updated_at, deleted_at, hash, canonical_version) VALUES ('06FBHBN5F0F8SDF15P21DNKT1W', 'status', 'backlog', 'in_progress', NULL, '2026-06-11 22:54:18', '2026-06-11 22:54:18', '2026-06-11 22:54:18', NULL, '2cadeabff0a0a89bbcc06db35dfa2f15', 2) ON CONFLICT(hash) DO NOTHING;
 INSERT INTO ticket_history (ticket_record_id, field, old_value, new_value, changed_by, changed_at, created_at, updated_at, deleted_at, hash, canonical_version) VALUES ('06FBHBN5F0F8SDF15P21DNKT1W', 'status', 'in_progress', 'done', NULL, '2026-06-11 22:57:42', '2026-06-11 22:57:42', '2026-06-11 22:57:42', NULL, 'cb060646e7e967d607dc013a75ec0a28', 2) ON CONFLICT(hash) DO NOTHING;
+INSERT INTO ticket_history (ticket_record_id, field, old_value, new_value, changed_by, changed_at, created_at, updated_at, deleted_at, hash, canonical_version) VALUES ('06FBHD098CV2N73823KX4Z99P4', 'status', 'backlog', 'in_progress', NULL, '2026-06-11 23:01:24', '2026-06-11 23:01:24', '2026-06-11 23:01:24', NULL, '33ef6141e9af3e6957def829e635b138', 2) ON CONFLICT(hash) DO NOTHING;
+INSERT INTO ticket_history (ticket_record_id, field, old_value, new_value, changed_by, changed_at, created_at, updated_at, deleted_at, hash, canonical_version) VALUES ('06FB0TNQM5W6VN98RQM6S22X28', 'status', 'backlog', 'done', NULL, '2026-06-11 23:04:46', '2026-06-11 23:04:46', '2026-06-11 23:04:46', NULL, '5b0e12802a8f9c0b90f8b08e97f85e29', 2) ON CONFLICT(hash) DO NOTHING;
+INSERT INTO ticket_history (ticket_record_id, field, old_value, new_value, changed_by, changed_at, created_at, updated_at, deleted_at, hash, canonical_version) VALUES ('06FBHD098CV2N73823KX4Z99P4', 'status', 'in_progress', 'done', NULL, '2026-06-11 23:04:46', '2026-06-11 23:04:46', '2026-06-11 23:04:46', NULL, '5d8d8c7a17da4894510db957e7af3c3f', 2) ON CONFLICT(hash) DO NOTHING;

.pql/changelog/tickets/2026-06.sql

@@ -4066,3 +4066,26 @@ Fix: generate a token in the lock file (Claude Code /ide lock format has a slot
 INSERT INTO tickets (record_id, type, parent_record_id, title, description, status, priority, assigned_to, team, decision_ref, created_at, updated_at, deleted_at, hash, canonical_version) VALUES ('06FBHBN5F0F8SDF15P21DNKT1W', 'bug', '06FBHBGHNEQTAEPGNJKN42C1E8', 'MCP HTTP server exposes the full dispatcher with zero auth', 'lib/src/ipc/mcp_server.dart:138-195, started unconditionally at boot (lib/main.dart:174-180). D-71 threat model (another user on the same host must not drive my IDE) is enforced with 0600 on the unix socket — then bypassed wholesale by an unauthenticated localhost HTTP port that, since D-86, serves every clide verb as a tool.
 
 Fix: generate a token in the lock file (Claude Code /ide lock format has a slot for it) and require the auth header on every request. Tests: request without token is rejected; token round-trips via the lock file.', 'done', 'critical', NULL, NULL, NULL, '2026-06-11 21:55:13', '2026-06-11 22:57:42', NULL, '14de71ed19e921a370001097887a7e6f', 2) ON CONFLICT(record_id) DO UPDATE SET type=excluded.type, parent_record_id=excluded.parent_record_id, title=excluded.title, description=excluded.description, status=excluded.status, priority=excluded.priority, assigned_to=excluded.assigned_to, team=excluded.team, decision_ref=excluded.decision_ref, updated_at=excluded.updated_at, deleted_at=excluded.deleted_at, hash=excluded.hash, canonical_version=excluded.canonical_version WHERE excluded.updated_at > tickets.updated_at OR (excluded.updated_at = tickets.updated_at AND excluded.hash > tickets.hash);
+INSERT INTO tickets (record_id, type, parent_record_id, title, description, status, priority, assigned_to, team, decision_ref, created_at, updated_at, deleted_at, hash, canonical_version) VALUES ('06FBHD098CV2N73823KX4Z99P4', 'task', '06FBHBGHNEQTAEPGNJKN42C1E8', 'ValueStream (replay-latest) wrapper; retrofit statusStream, busyStream, pendingPromptStream', 'Broadcast streams that carry STATE (not events) drop the current value for late subscribers. This one shape caused T-274 (status bar blank — root cause appended there), the meta sidebar''s manual compensation, and the prompt-stream''s initialData workaround.
+
+Fix: write one small ValueStream<T> wrapper (a broadcast stream that replays the latest value to each new subscriber, plus a .value getter) in the kernel; retrofit statusStream, busyStream, and pendingPromptStream in the claude builtin; delete the per-site workarounds it obsoletes. No third-party dep (rxdart) — prefer-zero-deps; the wrapper is ~30 LOC.
+
+Acceptance: unit tests for the wrapper (late subscriber gets latest value; no value yet = no synthetic emit unless seeded); T-274 repro covered: subscribing after the init event still yields the status. Closing this should make T-274 fixable in one line at the call site.', 'in_progress', 'high', NULL, NULL, NULL, '2026-06-11 22:01:07', '2026-06-11 23:01:24', NULL, '490fa0773537afc3ec2be0756960dc05', 2) ON CONFLICT(record_id) DO UPDATE SET type=excluded.type, parent_record_id=excluded.parent_record_id, title=excluded.title, description=excluded.description, status=excluded.status, priority=excluded.priority, assigned_to=excluded.assigned_to, team=excluded.team, decision_ref=excluded.decision_ref, updated_at=excluded.updated_at, deleted_at=excluded.deleted_at, hash=excluded.hash, canonical_version=excluded.canonical_version WHERE excluded.updated_at > tickets.updated_at OR (excluded.updated_at = tickets.updated_at AND excluded.hash > tickets.hash);
+INSERT INTO tickets (record_id, type, parent_record_id, title, description, status, priority, assigned_to, team, decision_ref, created_at, updated_at, deleted_at, hash, canonical_version) VALUES ('06FB0TNQM5W6VN98RQM6S22X28', 'bug', '06FB0TNQM5TWC00GW0P3X02HZW', 'Claude bottom status bar often stays empty / doesn''t update', 'The bottom status-bar context slot for the Claude pane (model · permission-mode · context, T-145/T-150) frequently renders empty and doesn''t update. The slot is fed by the active pane''s status widget via the focus service (PaneContextStatusItem -> ClidePane.statusWidget in claude_pane.dart), sourced from StreamJsonSession.statusStream (model/permissionMode from the ''system/init'' event; cost/contextWindow from ''result'' events in stream_json_session.dart).
+
+Repro: open clide; the status line is often blank and stays blank until/unless a turn completes (or never populates).
+
+Likely suspects to investigate:
+- status only published while the pane is the focused contribution (active==true) — if focus isn''t on the Claude pane, the slot clears.
+- statusStream may not emit until the first ''result''/''init'' event; a resumed session (--resume) may not re-emit init, so model/mode never arrive.
+- _statusWidget returns null when _status.isEmpty AND no skills, so an unstarted/!init session shows nothing.
+- focus-slot wiring (FocusTracker) may not re-publish on pane (re)build / session rebind.
+
+Acceptance: the Claude status line shows model · mode · context promptly after a session starts/resumes and stays current across turns and focus changes; add a test covering the resumed-session (no fresh init) case.
+
+Root cause found and verified by the 2026-06-11 Fable review (fable-ous.md, epic T-359): statusStream is a plain broadcast controller — the system/init event fires while spawn() is still awaiting a 256KB transcript-tail read, before the pane ever subscribes (lib/builtin/claude/src/claude_pane.dart:322, lib/builtin/claude/src/session_orchestrator.dart:222-225). Fix: seed from session.status on bind, or make the stream replay-latest (see the ValueStream systemic ticket under T-359).', 'done', 'medium', NULL, NULL, NULL, '2026-06-08 07:26:13', '2026-06-11 23:04:46', NULL, '97024e51051e9ac66e65376e953a5faf', 2) ON CONFLICT(record_id) DO UPDATE SET type=excluded.type, parent_record_id=excluded.parent_record_id, title=excluded.title, description=excluded.description, status=excluded.status, priority=excluded.priority, assigned_to=excluded.assigned_to, team=excluded.team, decision_ref=excluded.decision_ref, updated_at=excluded.updated_at, deleted_at=excluded.deleted_at, hash=excluded.hash, canonical_version=excluded.canonical_version WHERE excluded.updated_at > tickets.updated_at OR (excluded.updated_at = tickets.updated_at AND excluded.hash > tickets.hash);
+INSERT INTO tickets (record_id, type, parent_record_id, title, description, status, priority, assigned_to, team, decision_ref, created_at, updated_at, deleted_at, hash, canonical_version) VALUES ('06FBHD098CV2N73823KX4Z99P4', 'task', '06FBHBGHNEQTAEPGNJKN42C1E8', 'ValueStream (replay-latest) wrapper; retrofit statusStream, busyStream, pendingPromptStream', 'Broadcast streams that carry STATE (not events) drop the current value for late subscribers. This one shape caused T-274 (status bar blank — root cause appended there), the meta sidebar''s manual compensation, and the prompt-stream''s initialData workaround.
+
+Fix: write one small ValueStream<T> wrapper (a broadcast stream that replays the latest value to each new subscriber, plus a .value getter) in the kernel; retrofit statusStream, busyStream, and pendingPromptStream in the claude builtin; delete the per-site workarounds it obsoletes. No third-party dep (rxdart) — prefer-zero-deps; the wrapper is ~30 LOC.
+
+Acceptance: unit tests for the wrapper (late subscriber gets latest value; no value yet = no synthetic emit unless seeded); T-274 repro covered: subscribing after the init event still yields the status. Closing this should make T-274 fixable in one line at the call site.', 'done', 'high', NULL, NULL, NULL, '2026-06-11 22:01:07', '2026-06-11 23:04:46', NULL, '9cd3d1777cfbe56c117a91aa3f303855', 2) ON CONFLICT(record_id) DO UPDATE SET type=excluded.type, parent_record_id=excluded.parent_record_id, title=excluded.title, description=excluded.description, status=excluded.status, priority=excluded.priority, assigned_to=excluded.assigned_to, team=excluded.team, decision_ref=excluded.decision_ref, updated_at=excluded.updated_at, deleted_at=excluded.deleted_at, hash=excluded.hash, canonical_version=excluded.canonical_version WHERE excluded.updated_at > tickets.updated_at OR (excluded.updated_at = tickets.updated_at AND excluded.hash > tickets.hash);

CHANGELOG.md

@@ -84,6 +84,12 @@ heading, and (b) bumping `pubspec.yaml` `version:` in the same commit.
   pane stops spinning, clears any unanswerable permission prompt, reports
   the exit in the status line, and logs the stderr tail. (T-361)
 
+- **The Claude status bar populates reliably after a session starts.** The
+  session's init event often fired before the pane subscribed and the plain
+  broadcast stream dropped it, leaving the model/mode/context line blank;
+  session state streams now replay their latest value to late subscribers.
+  (T-274, T-386)
+
 - **Accepting ExitPlanMode now leaves plan mode in the conversation panel.**
   Approving Claude's plan (the ExitPlanMode tool) transitioned the underlying
   session out of plan mode, but clide's tracked permission mode didn't follow,

lib/builtin/claude/src/stream_json_session.dart

@@ -19,6 +19,7 @@ import 'dart:convert';
 import 'dart:io';
 
 import 'package:clide/builtin/claude/src/transcript_reader.dart';
+import 'package:clide/src/util/value_stream.dart';
 
 /// The claude subprocess, abstracted so tests drive it without spawning.
 /// Fakes `extend` this and override what they drive; the defaults below
@@ -251,7 +252,9 @@ class StreamJsonSession {
   /// round-trips are answered by [_handleMcpMessage].
   final List<McpServer> _mcpServers;
   final _items = StreamController<ConversationItem>.broadcast();
-  final _statusCtl = StreamController<SessionStatus>.broadcast();
+  // State, not events — replay-latest so a subscriber that binds after the
+  // init event still sees the current status (T-386; root cause of T-274).
+  final _statusCtl = ValueStream<SessionStatus>();
   final _sessionIdCtl = StreamController<String>.broadcast();
   StreamSubscription<String>? _sub;
   SessionStatus _status = const SessionStatus();
@@ -284,7 +287,7 @@ class StreamJsonSession {
   /// Prompts awaiting a [resolvePrompt] decision, in arrival order. The head
   /// is the one currently shown in the composer zone.
   final _queue = <ToolPrompt>[];
-  final _pendingCtl = StreamController<ToolPrompt?>.broadcast();
+  final _pendingCtl = ValueStream<ToolPrompt?>.seeded(null);
 
   /// tool_use_ids that surfaced as a prompt — the view hides their raw
   /// tool-use card while pending (it shows as a prompt) but keeps the result.
@@ -309,7 +312,7 @@ class StreamJsonSession {
   /// Whether a turn is in flight (between a send and claude's `result`). Drives
   /// the composer's Stop affordance.
   bool _busy = false;
-  final _busyCtl = StreamController<bool>.broadcast();
+  final _busyCtl = ValueStream<bool>.seeded(false);
   bool get busy => _busy;
   Stream<bool> get busyStream => _busyCtl.stream;
 

lib/clide.dart

@@ -26,6 +26,7 @@ export 'src/ipc/paths.dart';
 export 'src/ipc/schema_v1.dart';
 export 'src/panes/event_sink.dart';
 export 'src/panes/pane.dart' show Pane, PaneKind;
+export 'src/util/value_stream.dart' show ValueStream;
 
 // clideName, clideTagline, clideVersion, clideRepository, clideCommit,
 // clideDate live in lib/src/build_info.g.dart, regenerated by every

lib/src/util/value_stream.dart

@@ -0,0 +1,70 @@
+/// Replay-latest broadcast value holder (T-386).
+///
+/// Broadcast streams drop the current value for late subscribers — the
+/// recurring bug factory behind T-274 (status bar blank because the
+/// `system/init` event fired before the pane subscribed) and the
+/// per-site `initialData` workarounds. A [ValueStream] carries STATE,
+/// not events: every new subscriber immediately receives the latest
+/// value (when one exists), then live updates.
+///
+/// Pure Dart — usable from the IPC/daemon layer and under `dart test`.
+library;
+
+import 'dart:async';
+
+class ValueStream<T> {
+  ValueStream();
+
+  ValueStream.seeded(T value) : _value = value, _hasValue = true;
+
+  final StreamController<T> _ctl = StreamController<T>.broadcast();
+  T? _value;
+  bool _hasValue = false;
+
+  /// Whether a value has been added (or seeded) yet. A fresh, unseeded
+  /// holder replays nothing — subscribers wait for the first [add].
+  bool get hasValue => _hasValue;
+
+  /// The latest value, or null before the first [add]. For a nullable
+  /// [T], disambiguate with [hasValue].
+  T? get valueOrNull => _value;
+
+  /// The latest value. Throws [StateError] before the first [add] —
+  /// callers that can race the first value should use [valueOrNull].
+  T get value {
+    if (!_hasValue) throw StateError('ValueStream has no value yet');
+    return _value as T;
+  }
+
+  void add(T value) {
+    _value = value;
+    _hasValue = true;
+    if (!_ctl.isClosed) _ctl.add(value);
+  }
+
+  /// A stream that replays the latest value (if any) to its subscriber,
+  /// then follows live updates. Each access returns a fresh
+  /// single-subscription stream, so every listener gets its own replay.
+  Stream<T> get stream {
+    late StreamController<T> out;
+    StreamSubscription<T>? sub;
+    out = StreamController<T>(
+      onListen: () {
+        if (_hasValue) out.add(_value as T);
+        if (_ctl.isClosed) {
+          out.close();
+          return;
+        }
+        sub = _ctl.stream.listen(out.add, onError: out.addError, onDone: out.close);
+      },
+      onPause: () => sub?.pause(),
+      onResume: () => sub?.resume(),
+      onCancel: () => sub?.cancel(),
+    );
+    return out.stream;
+  }
+
+  bool get isClosed => _ctl.isClosed;
+
+  Future<void> close() => _ctl.close();
+}

test/builtin/claude/stream_json_session_test.dart

@@ -201,6 +201,21 @@ void main() {
     expect(statuses, hasLength(1));
   });
 
+  // T-274 root cause: the init event fired before the pane subscribed and
+  // the plain broadcast stream dropped it — the status bar stayed blank.
+  test('subscribing AFTER the init event still yields the status (T-274/T-386)', () async {
+    proc.emit(initEvent());
+    await Future<void>.delayed(Duration.zero);
+
+    final late = <SessionStatus>[];
+    session.statusStream.listen(late.add);
+    await Future<void>.delayed(Duration.zero);
+
+    expect(late, hasLength(1), reason: 'replay-latest delivers the current status to late binders');
+    expect(late.single.model, 'claude-opus-4-7');
+    expect(late.single.permissionMode, 'default');
+  });
+
   test('captures the claude session id from the first event carrying it (T-185)', () async {
     final ids = <String>[];
     session.sessionIdResolved.listen(ids.add);
@@ -647,7 +662,9 @@ void main() {
     proc.emit(jsonEncode({'type': 'result', 'subtype': 'success'}));
     await Future<void>.delayed(Duration.zero);
     expect(session.busy, isFalse);
-    expect(busy, [true, false]);
+    // Leading false is the replayed seed — busyStream tells a new
+    // subscriber the CURRENT state before the live updates (T-386).
+    expect(busy, [false, true, false]);
   });
 
   test('dispose kills the process', () async {

test/util/value_stream_test.dart

@@ -0,0 +1,117 @@
+/// Tests for [ValueStream] — the replay-latest state holder (T-386).
+library;
+
+import 'package:clide/src/util/value_stream.dart';
+import 'package:test/test.dart';
+
+void main() {
+  test('a late subscriber receives the latest value immediately', () async {
+    final v = ValueStream<int>();
+    v.add(1);
+    v.add(2);
+    final got = <int>[];
+    v.stream.listen(got.add);
+    await Future<void>.delayed(Duration.zero);
+    expect(got, [2]);
+  });
+
+  test('an unseeded holder replays nothing until the first add', () async {
+    final v = ValueStream<int>();
+    final got = <int>[];
+    v.stream.listen(got.add);
+    await Future<void>.delayed(Duration.zero);
+    expect(got, isEmpty);
+    v.add(7);
+    await Future<void>.delayed(Duration.zero);
+    expect(got, [7]);
+  });
+
+  test('seeded constructor provides the initial value', () async {
+    final v = ValueStream<bool>.seeded(false);
+    expect(v.hasValue, isTrue);
+    expect(v.value, isFalse);
+    final got = <bool>[];
+    v.stream.listen(got.add);
+    await Future<void>.delayed(Duration.zero);
+    expect(got, [false]);
+  });
+
+  test('live updates flow to existing subscribers', () async {
+    final v = ValueStream<String>();
+    final got = <String>[];
+    v.stream.listen(got.add);
+    v.add('a');
+    v.add('b');
+    await Future<void>.delayed(Duration.zero);
+    expect(got, ['a', 'b']);
+  });
+
+  test('each stream access gives every subscriber its own replay', () async {
+    final v = ValueStream<int>.seeded(5);
+    final a = <int>[];
+    final b = <int>[];
+    v.stream.listen(a.add);
+    v.stream.listen(b.add);
+    v.add(6);
+    await Future<void>.delayed(Duration.zero);
+    expect(a, [5, 6]);
+    expect(b, [5, 6]);
+  });
+
+  test('value throws before the first add; valueOrNull is null', () {
+    final v = ValueStream<int>();
+    expect(() => v.value, throwsStateError);
+    expect(v.valueOrNull, isNull);
+    expect(v.hasValue, isFalse);
+  });
+
+  test('a nullable type can hold null as a real value', () async {
+    final v = ValueStream<String?>.seeded(null);
+    expect(v.hasValue, isTrue);
+    expect(v.valueOrNull, isNull);
+    final got = <String?>[];
+    v.stream.listen(got.add);
+    await Future<void>.delayed(Duration.zero);
+    expect(got, [null]);
+  });
+
+  test('close ends derived streams; a post-close subscriber still gets the replay', () async {
+    final v = ValueStream<int>();
+    v.add(3);
+    final done = <String>[];
+    v.stream.listen((_) {}, onDone: () => done.add('a'));
+    await v.close();
+    await Future<void>.delayed(Duration.zero);
+    expect(done, ['a']);
+    expect(v.isClosed, isTrue);
+
+    final got = <int>[];
+    var closed = false;
+    v.stream.listen(got.add, onDone: () => closed = true);
+    await Future<void>.delayed(Duration.zero);
+    expect(got, [3], reason: 'the last value survives close for late readers');
+    expect(closed, isTrue);
+  });
+
+  test('add after close updates the value without throwing', () {
+    final v = ValueStream<int>.seeded(1);
+    v.close();
+    v.add(2);
+    expect(v.value, 2);
+  });
+
+  test('pause/resume on a derived stream buffers updates', () async {
+    final v = ValueStream<int>();
+    final got = <int>[];
+    final sub = v.stream.listen(got.add);
+    v.add(1);
+    await Future<void>.delayed(Duration.zero);
+    sub.pause();
+    v.add(2);
+    await Future<void>.delayed(Duration.zero);
+    expect(got, [1]);
+    sub.resume();
+    await Future<void>.delayed(Duration.zero);
+    expect(got, [1, 2]);
+  });
+}