add the team chat inbox over the broker

Renders broker traffic as a chat timeline and makes the user a first-class
participant. The broker grows a Stream<TeamMessage> and a recipient field,
auto-registers a virtual `user` member, and gains sendAsUser. A Flutter-free
TeamChatModel (owned by the orchestrator) accumulates the feed and exposes
postAsUser with @-routing (a new at_commands helper mirroring slash) and an
optional interrupt that cancels the target's turn before delivery. One model
backs two surfaces: a compact cockpit widget that pops out into a full
workspace chat pane. CLI parity via clide.team-chat.open / .post.

T-180.

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

.pql/changelog/ticket_history/2026-05.sql

@@ -2292,3 +2292,5 @@ INSERT INTO ticket_history (ticket_id, field, old_value, new_value, changed_by,
 INSERT INTO ticket_history (ticket_id, field, old_value, new_value, changed_by, changed_at, created_at, updated_at, deleted_at, hash, canonical_version) VALUES ('T-181', 'status', 'backlog', 'in_progress', NULL, '2026-05-30 21:14:56', '2026-05-30 21:14:56', '2026-05-30 21:14:56', NULL, '6426dc0355b68f0fd572e52d53101fc4', 1) ON CONFLICT(hash) DO NOTHING;
 INSERT INTO ticket_history (ticket_id, field, old_value, new_value, changed_by, changed_at, created_at, updated_at, deleted_at, hash, canonical_version) VALUES ('T-181', 'status', 'in_progress', 'done', NULL, '2026-05-30 21:25:11', '2026-05-30 21:25:11', '2026-05-30 21:25:11', NULL, '81d8d388c7e4f53a4514f05cf5dbf37b', 1) ON CONFLICT(hash) DO NOTHING;
 INSERT INTO ticket_history (ticket_id, field, old_value, new_value, changed_by, changed_at, created_at, updated_at, deleted_at, hash, canonical_version) VALUES ('T-172', 'status', 'backlog', 'in_progress', NULL, '2026-05-30 21:25:12', '2026-05-30 21:25:12', '2026-05-30 21:25:12', NULL, 'e42556ec9d67731533b85e6da2a1bc9c', 1) ON CONFLICT(hash) DO NOTHING;
+INSERT INTO ticket_history (ticket_id, field, old_value, new_value, changed_by, changed_at, created_at, updated_at, deleted_at, hash, canonical_version) VALUES ('T-172', 'status', 'in_progress', 'done', NULL, '2026-05-30 21:34:56', '2026-05-30 21:34:56', '2026-05-30 21:34:56', NULL, 'f97c3bb01ea2bc5f969b34d4de09617a', 1) ON CONFLICT(hash) DO NOTHING;
+INSERT INTO ticket_history (ticket_id, field, old_value, new_value, changed_by, changed_at, created_at, updated_at, deleted_at, hash, canonical_version) VALUES ('T-180', 'status', 'backlog', 'in_progress', NULL, '2026-05-30 21:34:57', '2026-05-30 21:34:57', '2026-05-30 21:34:57', NULL, 'd73e085a28c3c4b2a7ce515d33012de4', 1) ON CONFLICT(hash) DO NOTHING;

.pql/changelog/tickets/2026-05.sql

@@ -2867,3 +2867,8 @@ INSERT INTO tickets (id, type, parent_id, title, description, status, priority,
 ---
 Refinement (2026-05-30, /whats-next): --fork-session CONFIRMED against the live binary (claude --help: "When resuming, create a new session ID instead of reusing the original (use with --resume or --continue)"). Fork argv = [''--resume'', <sourceSessionId>, ''--fork-session''] (no --session-id; the new branch gets its own id from the init event). Add forkSourceSessionId to SpawnSpec (session_orchestrator.dart); build argv via a forkSessionArgs helper in session_naming.dart; add ''fork'' to kClideOwnedCommands + a case in claude_pane._send; add a fork button to _memberRow in claude_meta_sidebar.dart. SEQUENCE AFTER T-171 (shares _memberRow + orchestrator).', 'in_progress', 'low', NULL, NULL, 'D-77', '2026-05-24 16:27:16', '2026-05-30 21:25:12', NULL, '1aaeba013d95c3d2baa5488f20183775', 1) ON CONFLICT(id) DO UPDATE SET type=excluded.type, parent_id=excluded.parent_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 (id, type, parent_id, title, description, status, priority, assigned_to, team, decision_ref, created_at, updated_at, deleted_at, hash, canonical_version) VALUES ('T-185', 'task', 'T-164', 'Capture the forked session''s real claude session-id from its init event', 'T-172 follow-up. A forked session is spawned with --resume <source> --fork-session and no --session-id, so claude assigns the branch a NEW session-id that only arrives in the stream-json init event. Today ManagedSession.sessionId for a fork holds a placeholder UUID (the orchestrator key), and the real claude session-id is never captured back. Consequence: the fork can''t itself be resumed/forked by id later, and any UI showing the session-id is wrong for forks. Do: capture session_id from the init/system event (StreamJsonSession already parses init for status — surface the session_id) and update the ManagedSession (make sessionId mutable or store a separate claudeSessionId that the orchestrator fills on init). Acceptance: after a fork''s first init event, the ManagedSession exposes the branch''s real claude session-id; a test drives an init event through a fake process and asserts the captured id. Surfaced by T-172; the fork argv/spawn/roster/original-unaffected behaviour already works without it.', 'backlog', 'low', NULL, NULL, 'D-77', '2026-05-30 21:34:26', '2026-05-30 21:34:26', NULL, 'f041094e4dea938f3e00997226e21edf', 1) ON CONFLICT(id) DO UPDATE SET type=excluded.type, parent_id=excluded.parent_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 (id, type, parent_id, title, description, status, priority, assigned_to, team, decision_ref, created_at, updated_at, deleted_at, hash, canonical_version) VALUES ('T-172', 'task', 'T-164', 'P2: fork-into-a-pane (--fork-session)', 'Branch a conversation into a new managed session/pane, reusing the orchestrator''s spawn plumbing. ''Fork'' = spawn a managed session seeded from another session''s context via --resume + --fork-session (resume the source, but create a new session-id so the branch diverges without touching the original). Surface it as a slash action and a sidebar/roster button on a session. Acceptance: forking an active session opens a new pane continuing from its context, independent thereafter; the original is unaffected; tests for the fork argv + the new managed session appearing in the roster. Blocked by T-169 (orchestrator).
+
+---
+Refinement (2026-05-30, /whats-next): --fork-session CONFIRMED against the live binary (claude --help: "When resuming, create a new session ID instead of reusing the original (use with --resume or --continue)"). Fork argv = [''--resume'', <sourceSessionId>, ''--fork-session''] (no --session-id; the new branch gets its own id from the init event). Add forkSourceSessionId to SpawnSpec (session_orchestrator.dart); build argv via a forkSessionArgs helper in session_naming.dart; add ''fork'' to kClideOwnedCommands + a case in claude_pane._send; add a fork button to _memberRow in claude_meta_sidebar.dart. SEQUENCE AFTER T-171 (shares _memberRow + orchestrator).', 'done', 'low', NULL, NULL, 'D-77', '2026-05-24 16:27:16', '2026-05-30 21:34:56', NULL, '8e8e43c735d6376e3eb1531a4f682b52', 1) ON CONFLICT(id) DO UPDATE SET type=excluded.type, parent_id=excluded.parent_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 (id, type, parent_id, title, description, status, priority, assigned_to, team, decision_ref, created_at, updated_at, deleted_at, hash, canonical_version) VALUES ('T-180', 'task', 'T-164', 'Team message inbox — broker chat (sidebar widget + poppable pane)', 'A team chat / message inbox: render the clide broker traffic as a chat-client timeline and make the user a first-class participant. (1) Timeline: every inter-agent message (send_message/broadcast) shown as chat rows with a colour-coded sender chip (tyre/gestalt/lead/you/...). (2) User as a broker participant: extend the T-170 broker so send_message(to: user) delivers into the inbox, and the team-awareness roster injected into each agent lists "you" as addressable; the user can post into the channel. (3) @-routing from the user: a recipient picker / @name parses to a broker route, @team (or no tag) broadcasts; reuse the slash-typeahead machinery for @-completion. (4) Interrupt tickbox on the composer: unchecked queues the message into the target next turn (normal broker delivery); checked sends an interrupt control_request to the target session (cancels its current turn) then delivers; default OFF. (5) One chat model, two surfaces: a compact sidebar widget in the cockpit (live feed + quick @-post) that pops out into a full chat pane. Wireframes: docs/design/wireframes/claude-prompts/05-team-cockpit-sidebar.png (widget) + 06-team-chat-pane.png (pane). Acceptance: broker messages render as chat; user posts route by @tag (one agent) or broadcast; interrupt tickbox cancels+delivers vs queues; widget and pane share one model; tests for routing + interrupt + render. Resolves the user-participation gaps from the team-mode screen analysis. Blocked by T-170 (broker).', 'in_progress', 'medium', NULL, NULL, 'D-77', '2026-05-25 09:15:58', '2026-05-30 21:34:57', NULL, 'caa8f38a5ae02650d2b3552a00ab796e', 1) ON CONFLICT(id) DO UPDATE SET type=excluded.type, parent_id=excluded.parent_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

@@ -75,6 +75,10 @@ heading, and (b) bumping `pubspec.yaml` `version:` in the same commit.
 - Fork a Claude conversation into a new pane — `/fork` (or a roster Fork
   button / `clide.agent.fork`) branches a session via `--resume … --fork-session`,
   opening an independent continuation that leaves the original untouched. (T-172, D-77)
+- Team chat inbox — broker traffic renders as a chat timeline (colour-coded
+  sender chips), in a compact cockpit widget that pops out to a full pane. The
+  user is a first-class participant: post with `@name` routing (or broadcast),
+  with an interrupt tickbox that cancels the target's turn before delivery. (T-180, D-77)
 - Team coordination broker (T-170, D-77) — clide hosts an in-process MCP
   server (`clide-team`) for managed sessions over the stream-json control
   channel, giving agents tools to message each other, broadcast, see the

lib/builtin/claude/src/at_commands.dart

@@ -0,0 +1,91 @@
+/// Pure helpers for `@`-name completion in the team chat composer (T-180).
+///
+/// Mirrors the slash_commands.dart API so the composer can use the same
+/// LayerLink + OverlayEntry overlay pattern for both typeaheads.
+/// Flutter-free — cheap to unit-test.
+library;
+
+bool _isWs(String c) => c == ' ' || c == '\t' || c == '\n';
+
+/// An in-progress `@name` query at the cursor — the `@` position and the
+/// word typed after it so far.
+class AtQuery {
+  const AtQuery({required this.start, required this.query});
+
+  /// Index of the `@` in the text.
+  final int start;
+
+  /// Text between the `@` and the cursor (no leading `@`, no whitespace).
+  final String query;
+
+  @override
+  bool operator ==(Object other) => other is AtQuery && other.start == start && other.query == query;
+
+  @override
+  int get hashCode => Object.hash(start, query);
+}
+
+/// The `@` query at [cursor] in [text], or null when the cursor isn't inside
+/// an `@` token. Matches `@name` at the start of the text or right after
+/// whitespace; does NOT match mid-word `@` (e.g. an email address).
+AtQuery? activeAtQuery(String text, int cursor) {
+  if (cursor < 0 || cursor > text.length) return null;
+  var start = cursor;
+  while (start > 0 && !_isWs(text[start - 1])) {
+    start--;
+  }
+  if (start >= cursor) return null; // empty run
+  if (text[start] != '@') return null; // run doesn't start with @
+  return AtQuery(start: start, query: text.substring(start + 1, cursor));
+}
+
+/// Member names matching [query] (case-insensitive prefix), de-duplicated,
+/// sorted, capped at [limit]. Always includes `team` (broadcast alias) as the
+/// first entry when the query is empty or matches.
+///
+/// [names] should be the broker's member display names (including `user`);
+/// pass them all — this helper will NOT filter out `user` because the
+/// composer may legitimately let an agent @-reply to the user.
+List<String> filterAtNames(String query, Iterable<String> names, {int limit = 8}) {
+  const broadcast = 'team';
+  final q = query.toLowerCase();
+  final seen = <String>{};
+  final matches = <String>[];
+  // Broadcast alias first.
+  if (broadcast.startsWith(q) && seen.add(broadcast)) matches.add(broadcast);
+  for (final n in names) {
+    if (n.toLowerCase().startsWith(q) && seen.add(n)) matches.add(n);
+  }
+  matches.sort((a, b) {
+    // Keep `team` pinned first when it's present.
+    if (a == broadcast) return -1;
+    if (b == broadcast) return 1;
+    return a.compareTo(b);
+  });
+  return matches.length > limit ? matches.sublist(0, limit) : matches;
+}
+
+/// Replace the `@` token described by [q] in [text] with `@<name> `,
+/// returning the new text and the cursor offset just past the inserted space.
+({String text, int cursor}) completeAt(String text, AtQuery q, String name) {
+  final insert = '@$name ';
+  final end = q.start + 1 + q.query.length;
+  return (text: text.replaceRange(q.start, end, insert), cursor: q.start + insert.length);
+}
+
+/// Parse a leading `@name` tag from the start of [text] (trimmed). Returns
+/// the recipient name and the remaining body, or `(null, text)` when there
+/// is no tag. `@team` resolves to null (broadcast).
+({String? recipient, String body}) parseAtTag(String text) {
+  final trimmed = text.trimLeft();
+  if (!trimmed.startsWith('@')) return (recipient: null, body: trimmed);
+  final ws = trimmed.indexOf(RegExp(r'\s'));
+  if (ws < 0) {
+    // Entire text is just the tag — no body.
+    final tag = trimmed.substring(1);
+    return (recipient: tag == 'team' ? null : tag, body: '');
+  }
+  final tag = trimmed.substring(1, ws);
+  final body = trimmed.substring(ws).trimLeft();
+  return (recipient: tag == 'team' ? null : tag, body: body);
+}

lib/builtin/claude/src/claude_meta_sidebar.dart

@@ -29,6 +29,7 @@ import 'package:clide/builtin/claude/src/claude_stats.dart';
 import 'package:clide/builtin/claude/src/claude_status.dart' show formatTokenCount, permissionModeLabel, shortModelLabel;
 import 'package:clide/builtin/claude/src/session_orchestrator.dart';
 import 'package:clide/builtin/claude/src/team_broker.dart' show TeamBroker, TeamTask;
+import 'package:clide/builtin/claude/src/team_chat_sidebar.dart' show TeamChatSidebar;
 import 'package:clide/builtin/claude/src/team_panel_host.dart' show teamColor;
 import 'package:clide/builtin/claude/src/transcript_publisher.dart' show ClaudeConversation;
 import 'package:clide/builtin/claude/src/transcript_reader.dart' show SessionStatus;
@@ -348,10 +349,17 @@ class _ClaudeMetaSidebarState extends State<ClaudeMetaSidebar> {
       children.add(_taskSection(tokens));
     }
 
-    // MESSAGES section: placeholder seam for T-180 to fill.
+    // MESSAGES section (T-180): live broker chat feed + quick-post composer.
-    // T-180 will replace this Container with the live message feed.
+    final chatModel = _orchestrator?.chatModel;
-    children.add(const SizedBox(height: 12));
+    final broker = _orchestrator?.broker;
-    children.add(_messagesSectionPlaceholder(tokens));
+    if (chatModel != null && broker != null) {
+      children.add(const SizedBox(height: 12));
+      children.add(TeamChatSidebar(
+        model: chatModel,
+        broker: broker,
+        onPopOut: _openChatPane,
+      ));
+    }
 
     return ListView(
       padding: const EdgeInsets.all(12),
@@ -370,9 +378,9 @@ class _ClaudeMetaSidebarState extends State<ClaudeMetaSidebar> {
     );
   }
 
-  /// Minimal seam for T-180 — the message feed and composer will land here.
+  /// Open the full team chat pane in the workspace (T-180).
-  Widget _messagesSectionPlaceholder(SurfaceTokens tokens) {
+  void _openChatPane() {
-    return ClideText('MESSAGES', fontSize: clideFontSmall, color: tokens.globalTextMuted);
+    ClideKernel.of(context).panels.activateTab(Slots.workspace, 'claude.team-chat');
   }
 
   // --- Config ---------------------------------------------------------------

lib/builtin/claude/src/extension.dart

@@ -9,6 +9,7 @@ import 'package:clide/builtin/claude/src/pane_context_status.dart';
 import 'package:clide/builtin/claude/src/claude_meta_sidebar.dart';
 import 'package:clide/builtin/claude/src/session_index.dart';
 import 'package:clide/builtin/claude/src/session_storage.dart';
+import 'package:clide/builtin/claude/src/team_chat_sidebar.dart' show TeamChatPane;
 import 'package:clide/builtin/claude/src/team_panel_host.dart';
 import 'package:clide/extension/extension.dart';
 import 'package:clide/kernel/kernel.dart';
@@ -174,6 +175,56 @@ class ClaudeExtension extends ClideExtension {
             return IpcResponse.ok(id: '', data: {'taskId': taskId, 'toId': toId, 'ok': ok});
           },
         ),
+        // T-180: full team chat pane opened as a workspace tab.
+        // Shares the TeamChatModel with the sidebar widget.
+        TabContribution(
+          id: 'claude.team-chat',
+          slot: Slots.workspace,
+          title: 'Team Chat',
+          titleKey: 'tab.title',
+          i18nNamespace: id,
+          priority: 85,
+          build: (_) {
+            final orch = _orchestrator;
+            if (orch == null) return const SizedBox.shrink();
+            return TeamChatPane(model: orch.chatModel, broker: orch.broker);
+          },
+        ),
+        // CLI parity: open the team chat pane from the shell.
+        // Usage: clide claude.team-chat.open
+        CommandContribution(
+          id: 'claude.team-chat.open',
+          command: 'claude.team-chat.open',
+          title: 'Claude: open the team chat pane',
+          run: (args) async {
+            _ctx?.panels.activateTab(Slots.workspace, 'claude.team-chat');
+            return IpcResponse.ok(id: '', data: const {'status': 'opened'});
+          },
+        ),
+        // Usage: clide claude.team-chat.post [@name] <text...>
+        // Posts a message into the broker channel as the user.
+        // Leading @name tag selects the recipient; omit for broadcast.
+        CommandContribution(
+          id: 'claude.team-chat.post',
+          command: 'claude.team-chat.post',
+          title: 'Claude: post a message into the team channel as the user',
+          run: (args) async {
+            if (args.isEmpty) return IpcResponse.ok(id: '', data: const {'error': 'usage: [@name] <text>'});
+            final raw = args.join(' ');
+            String? recipient;
+            String body = raw;
+            if (raw.startsWith('@')) {
+              final ws = raw.indexOf(RegExp(r'\s'));
+              if (ws > 0) {
+                final tag = raw.substring(1, ws);
+                recipient = (tag == 'team' || tag.isEmpty) ? null : tag;
+                body = raw.substring(ws).trim();
+              }
+            }
+            _orchestrator?.chatModel.postAsUser(body, toName: recipient);
+            return IpcResponse.ok(id: '', data: {'status': 'posted', if (recipient != null) 'to': recipient});
+          },
+        ),
         // claude.agent.fork: branch a managed session into a new fork session
         // (T-172, D-6 CLI/UI parity for the roster fork button).
         // Usage: clide claude.agent.fork <sourceSessionId> [<cwd>]

lib/builtin/claude/src/session_orchestrator.dart

@@ -19,6 +19,7 @@ import 'package:clide/builtin/claude/src/conversation_controller.dart';
 import 'package:clide/builtin/claude/src/session_naming.dart';
 import 'package:clide/builtin/claude/src/stream_json_session.dart';
 import 'package:clide/builtin/claude/src/team_broker.dart';
+import 'package:clide/builtin/claude/src/team_chat_model.dart';
 import 'package:clide/builtin/claude/src/transcript_reader.dart';
 import 'package:flutter/foundation.dart';
 
@@ -146,7 +147,12 @@ class ManagedSession {
 ClaudeSessionOrchestrator? activeSessionOrchestrator;
 
 class ClaudeSessionOrchestrator extends ChangeNotifier {
-  ClaudeSessionOrchestrator({ProcessFactory? processFactory}) : _factory = processFactory ?? _spawnClaude;
+  ClaudeSessionOrchestrator({ProcessFactory? processFactory}) : _factory = processFactory ?? _spawnClaude {
+    _chatModel = TeamChatModel(
+      broker: broker,
+      sessionResolver: (name) => byMemberName(name)?.session,
+    );
+  }
 
   final ProcessFactory _factory;
   final _sessions = <String, ManagedSession>{};
@@ -156,6 +162,13 @@ class ClaudeSessionOrchestrator extends ChangeNotifier {
   /// session's next turn (T-170).
   late final TeamBroker broker = TeamBroker(deliver: _deliverToSession);
 
+  /// The shared chat timeline and user-post logic (T-180). Both the compact
+  /// sidebar widget and the full workspace pane read from this model.
+  late final TeamChatModel _chatModel;
+
+  /// Exposes the shared chat model to widgets and panes.
+  TeamChatModel get chatModel => _chatModel;
+
   void _deliverToSession(String toId, String text) => _sessions[toId]?.session.send(text);
 
   static Future<StreamJsonProcess> _spawnClaude({required List<String> sessionArgs, required String cwd, Map<String, String>? env}) =>
@@ -328,6 +341,8 @@ class ClaudeSessionOrchestrator extends ChangeNotifier {
       m.conversation.dispose();
     }
     _sessions.clear();
+    _chatModel.dispose();
+    broker.dispose();
     super.dispose();
   }
 }

lib/builtin/claude/src/team_broker.dart

@@ -35,14 +35,26 @@ class TeamMemberRef {
 
 /// A message left for a member, in arrival order.
 class TeamMessage {
-  const TeamMessage({required this.from, required this.text, required this.at, this.broadcast = false});
+  const TeamMessage({
+    required this.from,
+    required this.text,
+    required this.at,
+    this.to,
+    this.broadcast = false,
+  });
   final String from;
+
+  /// Recipient name: a single member's display name (direct message), `null`
+  /// for a broadcast (every member), or the special value `'user'` when the
+  /// broker surfaces the message to the chat model rather than a session.
+  final String? to;
   final String text;
   final DateTime at;
   final bool broadcast;
 
   Map<String, dynamic> toJson() => {
         'from': from,
+        if (to != null) 'to': to,
         'text': text,
         'at': at.toIso8601String(),
         if (broadcast) 'broadcast': true,
@@ -78,7 +90,12 @@ typedef MessageDelivery = void Function(String toMemberId, String text);
 /// broadcast [StreamController]; consumers must not assume it fires on the
 /// Flutter event loop.
 class TeamBroker {
-  TeamBroker({MessageDelivery? deliver}) : _deliver = deliver;
+  TeamBroker({MessageDelivery? deliver}) : _deliver = deliver {
+    // The user is always a virtual team participant — agents can address them
+    // by name; messages routed to `user` surface in the chat model only (no
+    // stdin delivery). Registered at construction so the roster is consistent.
+    addMember(const TeamMemberRef(id: 'user', name: 'user', role: 'user'));
+  }
 
   final MessageDelivery? _deliver;
   final _members = <String, TeamMemberRef>{};
@@ -90,11 +107,17 @@ class TeamBroker {
   // --- Observability ---------------------------------------------------------
 
   final _changeCtl = StreamController<void>.broadcast();
+  final _messageCtl = StreamController<TeamMessage>.broadcast();
 
   /// Fires a void event whenever the task list or message state mutates.
   /// Broadcast — multiple listeners are supported.  Flutter-free.
   Stream<void> get changes => _changeCtl.stream;
 
+  /// Every inter-agent message (send_message / broadcast) in arrival order.
+  /// Also includes messages directed `to: 'user'` so the chat model can surface
+  /// them. Broadcast — multiple listeners are supported. Flutter-free.
+  Stream<TeamMessage> get messages => _messageCtl.stream;
+
   void _notify() {
     if (!_changeCtl.isClosed) _changeCtl.add(null);
   }
@@ -161,9 +184,10 @@ class TeamBroker {
     return true;
   }
 
-  /// Dispose — closes the [changes] stream controller.
+  /// Dispose — closes the [changes] and [messages] stream controllers.
   void dispose() {
     _changeCtl.close();
+    _messageCtl.close();
   }
 
   /// All members in registration order.
@@ -181,13 +205,34 @@ class TeamBroker {
 
   // --- Tool operations (scoped to the caller [fromId]) ---------------------
 
+  /// Post [text] from the human user into the channel. When [to] is null or
+  /// omitted the message is broadcast; otherwise it is delivered only to the
+  /// named member. The `user` member is the caller's virtual id — it is
+  /// excluded from the recipient list in the same way senders are excluded
+  /// from their own broadcasts.
+  void sendAsUser(String text, {String? to}) {
+    if (to == null || to.isEmpty || to == 'team') {
+      // Broadcast: deliver to every non-user member.
+      // emitToStream=false: the chat model already recorded the local entry.
+      for (final m in _members.values) {
+        if (m.id == 'user') continue;
+        _enqueue(m.id, TeamMessage(from: 'user', to: null, text: text, at: DateTime.now(), broadcast: true), broadcast: true, emitToStream: false);
+      }
+    } else {
+      // Directed: deliver to the named member.
+      final target = _byName(to);
+      if (target == null || target.id == 'user') return;
+      _enqueue(target.id, TeamMessage(from: 'user', to: target.name, text: text, at: DateTime.now()), emitToStream: false);
+    }
+  }
+
   /// Deliver [text] to the single member named [toName].
   Map<String, dynamic> sendMessage(String fromId, String toName, String text) {
     final target = _byName(toName);
     if (target == null) {
       return {'ok': false, 'error': 'No teammate named "$toName". Use list_teammates to see who is on the team.'};
     }
-    _enqueue(target.id, TeamMessage(from: _nameOf(fromId), text: text, at: DateTime.now()));
+    _enqueue(target.id, TeamMessage(from: _nameOf(fromId), to: target.name, text: text, at: DateTime.now()));
     return {'ok': true, 'to': target.name};
   }
 
@@ -197,7 +242,7 @@ class TeamBroker {
     final recipients = <String>[];
     for (final m in _members.values) {
       if (m.id == fromId) continue;
-      _enqueue(m.id, TeamMessage(from: fromName, text: text, at: DateTime.now(), broadcast: true), broadcast: true);
+      _enqueue(m.id, TeamMessage(from: fromName, to: null, text: text, at: DateTime.now(), broadcast: true), broadcast: true);
       recipients.add(m.name);
     }
     return {'ok': true, 'recipients': recipients};
@@ -263,8 +308,20 @@ class TeamBroker {
     };
   }
 
-  void _enqueue(String toId, TeamMessage msg, {bool broadcast = false}) {
+  void _enqueue(String toId, TeamMessage msg, {bool broadcast = false, bool emitToStream = true}) {
     (_inboxes[toId] ??= <TeamMessage>[]).add(msg);
+    // Emit every message to the chat model stream before (possibly) delivering
+    // to the session stdin. The `user` member is a virtual participant — it has
+    // no session stdin, so delivery is skipped for it.
+    //
+    // [emitToStream] is false for user-originated messages that [TeamChatModel]
+    // already recorded locally — avoids double-adding them to the timeline.
+    if (emitToStream && !_messageCtl.isClosed) _messageCtl.add(msg);
+    if (toId == 'user') {
+      // User member: surfaced in the chat model only, no stdin delivery.
+      _notify();
+      return;
+    }
     final tag = broadcast ? '${msg.from} (broadcast)' : msg.from;
     // Gate delivery: muted members still accumulate inbox messages but the
     // live session callback is suppressed until unmuted (T-171).

lib/builtin/claude/src/team_chat_model.dart

@@ -0,0 +1,104 @@
+/// The shared chat model for team broker traffic (T-180).
+///
+/// Subscribes to the broker's [TeamBroker.messages] stream and keeps an
+/// append-only timeline of [TeamMessage]s. Both the compact sidebar widget
+/// and the full workspace pane read from this one model — they share state,
+/// they do NOT each hold their own copy.
+///
+/// [postAsUser] is the user's write path: it routes by @tag (one agent or
+/// broadcast) and, when the interrupt flag is set, calls [interrupt()] on the
+/// target session THEN delivers the message.
+///
+/// Flutter-free on purpose: this module (like [TeamBroker]) runs under
+/// `dart test`. Use [dart:async] Stream/StreamController for observability;
+/// do NOT use [ChangeNotifier].
+library;
+
+import 'dart:async';
+
+import 'package:clide/builtin/claude/src/team_broker.dart';
+import 'package:clide/builtin/claude/src/stream_json_session.dart';
+
+/// Resolves a session by orchestrator member name — injected by the
+/// orchestrator so the model doesn't depend on the Flutter-coupled
+/// [ClaudeSessionOrchestrator] type directly.
+typedef SessionResolver = StreamJsonSession? Function(String memberName);
+
+/// The shared timeline + user-post logic for team broker chat (T-180).
+///
+/// Lifetime matches the orchestrator: created once, subscribed to the broker,
+/// disposed when the orchestrator is torn down.
+class TeamChatModel {
+  TeamChatModel({
+    required TeamBroker broker,
+    SessionResolver? sessionResolver,
+  })  : _broker = broker,
+        _sessionResolver = sessionResolver {
+    _sub = broker.messages.listen(_onMessage);
+  }
+
+  final TeamBroker _broker;
+  final SessionResolver? _sessionResolver;
+  late final StreamSubscription<TeamMessage> _sub;
+
+  final _messages = <TeamMessage>[];
+
+  final _changeCtl = StreamController<void>.broadcast();
+
+  /// All broker messages in arrival order. Unmodifiable snapshot; new messages
+  /// are signalled via [changes].
+  List<TeamMessage> get messages => List.unmodifiable(_messages);
+
+  /// Fires a void event whenever a new message is appended. Broadcast —
+  /// multiple listeners are supported. Flutter-free.
+  Stream<void> get changes => _changeCtl.stream;
+
+  void _onMessage(TeamMessage msg) {
+    _messages.add(msg);
+    if (!_changeCtl.isClosed) _changeCtl.add(null);
+  }
+
+  // ---------------------------------------------------------------------------
+  // User post path
+  // ---------------------------------------------------------------------------
+
+  /// Post [text] as the user into the broker channel.
+  ///
+  /// - [toName] `null` or `'team'` → broadcast to all agents.
+  /// - [toName] a specific member name → `send_message(to: toName)`.
+  /// - [interrupt] `true` → call [StreamJsonSession.interrupt] on the target
+  ///   session first (cancels its current turn), then deliver. Default false.
+  ///
+  /// The message is also appended to the local timeline immediately so the
+  /// user sees it without waiting for the broker echo.
+  void postAsUser(String text, {String? toName, bool interrupt = false}) {
+    final from = 'user';
+    final isTeam = toName == null || toName.isEmpty || toName == 'team';
+
+    if (interrupt && !isTeam) {
+      // isTeam is false only when toName is a non-null, non-empty, non-'team'
+      // string, so Dart's flow analysis promotes it to non-null here.
+      _sessionResolver?.call(toName)?.interrupt();
+    }
+
+    if (isTeam) {
+      // Broadcast: create a local record and deliver via the broker.
+      final msg = TeamMessage(from: from, to: null, text: text, at: DateTime.now(), broadcast: true);
+      _messages.add(msg);
+      if (!_changeCtl.isClosed) _changeCtl.add(null);
+      _broker.sendAsUser(text);
+    } else {
+      // Directed message.
+      final msg = TeamMessage(from: from, to: toName, text: text, at: DateTime.now());
+      _messages.add(msg);
+      if (!_changeCtl.isClosed) _changeCtl.add(null);
+      _broker.sendAsUser(text, to: toName);
+    }
+  }
+
+  /// Dispose — cancels the broker subscription and closes the changes stream.
+  void dispose() {
+    _sub.cancel();
+    _changeCtl.close();
+  }
+}

lib/builtin/claude/src/team_chat_sidebar.dart

@@ -0,0 +1,636 @@
+/// Compact MESSAGES section for the Team cockpit sidebar (T-180, part 5).
+///
+/// Displays the live broker chat timeline as colour-coded rows and provides a
+/// quick @-post composer. Tapping the pop-out icon opens the full chat pane
+/// ([claude.team-chat] workspace tab).
+///
+/// Both this widget and [TeamChatPane] read from the same [TeamChatModel] —
+/// there is one model, two surfaces.
+library;
+
+import 'dart:async';
+
+import 'package:clide/builtin/claude/src/at_commands.dart';
+import 'package:clide/builtin/claude/src/team_broker.dart' show TeamBroker, TeamMessage;
+import 'package:clide/builtin/claude/src/team_chat_model.dart';
+import 'package:clide/builtin/claude/src/team_panel_host.dart' show teamColor;
+import 'package:clide/kernel/kernel.dart';
+import 'package:clide/widgets/widgets.dart';
+import 'package:flutter/services.dart' show KeyDownEvent, LogicalKeyboardKey;
+import 'package:flutter/widgets.dart';
+
+/// Compact broker chat section embedded in the Team sidebar.
+///
+/// [model] is the shared [TeamChatModel] from the orchestrator.
+/// [broker] is used to read the current roster for @-completion.
+/// [onPopOut] is called when the user taps the pop-out icon to open the full
+///   pane — the extension wires this to `panels.activateTab`.
+class TeamChatSidebar extends StatefulWidget {
+  const TeamChatSidebar({
+    super.key,
+    required this.model,
+    required this.broker,
+    required this.onPopOut,
+  });
+
+  final TeamChatModel model;
+  final TeamBroker broker;
+  final VoidCallback onPopOut;
+
+  @override
+  State<TeamChatSidebar> createState() => _TeamChatSidebarState();
+}
+
+class _TeamChatSidebarState extends State<TeamChatSidebar> {
+  StreamSubscription<void>? _sub;
+  final _controller = TextEditingController();
+  final _focusNode = FocusNode(debugLabel: 'team-chat-sidebar');
+  final _layerLink = LayerLink();
+  OverlayEntry? _overlay;
+  List<String> _suggestions = const [];
+  AtQuery? _activeQuery;
+
+  @override
+  void initState() {
+    super.initState();
+    _sub = widget.model.changes.listen((_) {
+      if (mounted) setState(() {});
+    });
+    _controller.addListener(_onTextChanged);
+  }
+
+  @override
+  void dispose() {
+    _sub?.cancel();
+    _removeOverlay();
+    _controller.removeListener(_onTextChanged);
+    _controller.dispose();
+    _focusNode.dispose();
+    super.dispose();
+  }
+
+  void _onTextChanged() {
+    final text = _controller.text;
+    final cursor = _controller.selection.baseOffset;
+    if (cursor < 0) {
+      _updateSuggestions(null);
+      return;
+    }
+    final q = activeAtQuery(text, cursor);
+    if (q == null) {
+      _updateSuggestions(null);
+      return;
+    }
+    final names = widget.broker.members.map((m) => m.name).where((n) => n != 'user');
+    final matches = filterAtNames(q.query, names);
+    _updateSuggestions(matches.isEmpty ? null : matches, query: q);
+  }
+
+  void _updateSuggestions(List<String>? suggestions, {AtQuery? query}) {
+    final newSuggestions = suggestions ?? const <String>[];
+    if (newSuggestions == _suggestions && query == _activeQuery) return;
+    setState(() {
+      _suggestions = newSuggestions;
+      _activeQuery = query;
+    });
+    if (newSuggestions.isEmpty) {
+      _removeOverlay();
+    } else {
+      _showOverlay();
+    }
+  }
+
+  void _showOverlay() {
+    _removeOverlay();
+    final entry = OverlayEntry(
+        builder: (_) => _AtOverlay(
+              layerLink: _layerLink,
+              suggestions: _suggestions,
+              onSelect: _completeName,
+            ));
+    _overlay = entry;
+    Overlay.of(context).insert(entry);
+  }
+
+  void _removeOverlay() {
+    _overlay?.remove();
+    _overlay = null;
+  }
+
+  void _completeName(String name) {
+    final q = _activeQuery;
+    if (q == null) return;
+    final result = completeAt(_controller.text, q, name);
+    _controller.value = TextEditingValue(
+      text: result.text,
+      selection: TextSelection.collapsed(offset: result.cursor),
+    );
+    _removeOverlay();
+    setState(() {
+      _suggestions = const [];
+      _activeQuery = null;
+    });
+  }
+
+  void _submit(String raw) {
+    final text = raw.trim();
+    if (text.isEmpty) return;
+    final parsed = parseAtTag(text);
+    widget.model.postAsUser(parsed.body.isEmpty ? text : parsed.body, toName: parsed.recipient);
+    _controller.clear();
+    _removeOverlay();
+  }
+
+  KeyEventResult _handleKeyEvent(FocusNode node, KeyEvent event) {
+    if (event is KeyDownEvent && event.logicalKey == LogicalKeyboardKey.escape) {
+      _removeOverlay();
+      setState(() {
+        _suggestions = const [];
+        _activeQuery = null;
+      });
+      return KeyEventResult.handled;
+    }
+    return KeyEventResult.ignored;
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final tokens = ClideTheme.of(context).surface;
+    final messages = widget.model.messages;
+
+    return Column(
+      crossAxisAlignment: CrossAxisAlignment.start,
+      children: [
+        // Section header row with pop-out icon.
+        Row(
+          children: [
+            Expanded(
+              child: ClideText('MESSAGES', fontSize: clideFontSmall, color: tokens.globalTextMuted),
+            ),
+            Semantics(
+              button: true,
+              label: 'Open full chat pane',
+              excludeSemantics: true,
+              onTap: widget.onPopOut,
+              child: ClideTappable(
+                tooltip: 'Open full chat',
+                onTap: widget.onPopOut,
+                builder: (ctx, hovered, _) => Padding(
+                  padding: const EdgeInsets.symmetric(horizontal: 2, vertical: 1),
+                  child: ClideIcon(
+                    PhosphorIcons.arrowsOutSimple,
+                    size: 10,
+                    color: hovered ? tokens.globalForeground : tokens.globalTextMuted,
+                  ),
+                ),
+              ),
+            ),
+          ],
+        ),
+        const SizedBox(height: 4),
+        // Last 5 messages (compact feed).
+        if (messages.isEmpty)
+          Padding(
+            padding: const EdgeInsets.only(bottom: 4),
+            child: ClideText('No messages yet.', muted: true, fontSize: clideFontSmall),
+          )
+        else
+          for (final msg in messages.length > 5 ? messages.sublist(messages.length - 5) : messages)
+            _ChatRow(key: ValueKey(msg.at.microsecondsSinceEpoch), message: msg, tokens: tokens),
+        const SizedBox(height: 6),
+        // Quick-post composer.
+        CompositedTransformTarget(
+          link: _layerLink,
+          child: Focus(
+            onKeyEvent: _handleKeyEvent,
+            child: _ChatInputField(
+              controller: _controller,
+              focusNode: _focusNode,
+              tokens: tokens,
+              onSubmit: _submit,
+              placeholder: '@name or @team …',
+            ),
+          ),
+        ),
+      ],
+    );
+  }
+}
+
+// ---------------------------------------------------------------------------
+// Full team chat pane (workspace tab)
+// ---------------------------------------------------------------------------
+
+/// Full-height broker chat pane opened as a workspace tab (T-180).
+///
+/// Reads from the same [TeamChatModel] as [TeamChatSidebar]. Supports the
+/// interrupt tickbox and full @-completion.
+class TeamChatPane extends StatefulWidget {
+  const TeamChatPane({
+    super.key,
+    required this.model,
+    required this.broker,
+  });
+
+  final TeamChatModel model;
+  final TeamBroker broker;
+
+  @override
+  State<TeamChatPane> createState() => _TeamChatPaneState();
+}
+
+class _TeamChatPaneState extends State<TeamChatPane> {
+  StreamSubscription<void>? _sub;
+  final _controller = TextEditingController();
+  final _focusNode = FocusNode(debugLabel: 'team-chat-pane');
+  final _layerLink = LayerLink();
+  final _scrollController = ScrollController();
+  OverlayEntry? _overlay;
+  List<String> _suggestions = const [];
+  AtQuery? _activeQuery;
+  bool _interrupt = false;
+
+  @override
+  void initState() {
+    super.initState();
+    _sub = widget.model.changes.listen((_) {
+      if (mounted) {
+        setState(() {});
+        // Scroll to bottom on new message.
+        WidgetsBinding.instance.addPostFrameCallback((_) {
+          if (_scrollController.hasClients) {
+            _scrollController.animateTo(
+              _scrollController.position.maxScrollExtent,
+              duration: const Duration(milliseconds: 120),
+              curve: Curves.easeOut,
+            );
+          }
+        });
+      }
+    });
+    _controller.addListener(_onTextChanged);
+  }
+
+  @override
+  void dispose() {
+    _sub?.cancel();
+    _removeOverlay();
+    _controller.removeListener(_onTextChanged);
+    _controller.dispose();
+    _focusNode.dispose();
+    _scrollController.dispose();
+    super.dispose();
+  }
+
+  void _onTextChanged() {
+    final text = _controller.text;
+    final cursor = _controller.selection.baseOffset;
+    if (cursor < 0) {
+      _updateSuggestions(null);
+      return;
+    }
+    final q = activeAtQuery(text, cursor);
+    if (q == null) {
+      _updateSuggestions(null);
+      return;
+    }
+    final names = widget.broker.members.map((m) => m.name).where((n) => n != 'user');
+    final matches = filterAtNames(q.query, names);
+    _updateSuggestions(matches.isEmpty ? null : matches, query: q);
+  }
+
+  void _updateSuggestions(List<String>? suggestions, {AtQuery? query}) {
+    final newSuggestions = suggestions ?? const <String>[];
+    if (newSuggestions == _suggestions && query == _activeQuery) return;
+    setState(() {
+      _suggestions = newSuggestions;
+      _activeQuery = query;
+    });
+    if (newSuggestions.isEmpty) {
+      _removeOverlay();
+    } else {
+      _showOverlay();
+    }
+  }
+
+  void _showOverlay() {
+    _removeOverlay();
+    final entry = OverlayEntry(
+        builder: (_) => _AtOverlay(
+              layerLink: _layerLink,
+              suggestions: _suggestions,
+              onSelect: _completeName,
+            ));
+    _overlay = entry;
+    Overlay.of(context).insert(entry);
+  }
+
+  void _removeOverlay() {
+    _overlay?.remove();
+    _overlay = null;
+  }
+
+  void _completeName(String name) {
+    final q = _activeQuery;
+    if (q == null) return;
+    final result = completeAt(_controller.text, q, name);
+    _controller.value = TextEditingValue(
+      text: result.text,
+      selection: TextSelection.collapsed(offset: result.cursor),
+    );
+    _removeOverlay();
+    setState(() {
+      _suggestions = const [];
+      _activeQuery = null;
+    });
+  }
+
+  void _submit(String raw) {
+    final text = raw.trim();
+    if (text.isEmpty) return;
+    final parsed = parseAtTag(text);
+    widget.model.postAsUser(
+      parsed.body.isEmpty ? text : parsed.body,
+      toName: parsed.recipient,
+      interrupt: _interrupt,
+    );
+    _controller.clear();
+    _removeOverlay();
+  }
+
+  KeyEventResult _handleKeyEvent(FocusNode node, KeyEvent event) {
+    if (event is KeyDownEvent && event.logicalKey == LogicalKeyboardKey.escape) {
+      _removeOverlay();
+      setState(() {
+        _suggestions = const [];
+        _activeQuery = null;
+      });
+      return KeyEventResult.handled;
+    }
+    return KeyEventResult.ignored;
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final tokens = ClideTheme.of(context).surface;
+    final messages = widget.model.messages;
+
+    return Column(
+      crossAxisAlignment: CrossAxisAlignment.stretch,
+      children: [
+        // Pane header.
+        Container(
+          padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
+          decoration: BoxDecoration(
+            border: Border(bottom: BorderSide(color: tokens.panelBorder)),
+          ),
+          child: ClideText('Team Chat', fontSize: clideFontSmall, color: tokens.globalTextMuted),
+        ),
+        // Timeline.
+        Expanded(
+          child: messages.isEmpty
+              ? Center(child: ClideText('No messages yet.', muted: true, fontSize: clideFontSmall))
+              : ListView.builder(
+                  controller: _scrollController,
+                  padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
+                  itemCount: messages.length,
+                  itemBuilder: (_, i) => _ChatRow(
+                    key: ValueKey(messages[i].at.microsecondsSinceEpoch),
+                    message: messages[i],
+                    tokens: tokens,
+                  ),
+                ),
+        ),
+        // Composer + interrupt tickbox.
+        Container(
+          padding: const EdgeInsets.fromLTRB(12, 6, 12, 8),
+          decoration: BoxDecoration(
+            border: Border(top: BorderSide(color: tokens.panelBorder)),
+          ),
+          child: Column(
+            crossAxisAlignment: CrossAxisAlignment.start,
+            children: [
+              // Interrupt tickbox.
+              GestureDetector(
+                onTap: () => setState(() => _interrupt = !_interrupt),
+                child: MouseRegion(
+                  cursor: SystemMouseCursors.click,
+                  child: Row(
+                    mainAxisSize: MainAxisSize.min,
+                    children: [
+                      Semantics(
+                        checked: _interrupt,
+                        label: 'Interrupt target session',
+                        excludeSemantics: true,
+                        onTap: () => setState(() => _interrupt = !_interrupt),
+                        child: Container(
+                          width: 12,
+                          height: 12,
+                          margin: const EdgeInsets.only(right: 5),
+                          decoration: BoxDecoration(
+                            color: _interrupt ? tokens.globalFocus.withAlpha(40) : const Color(0x00000000),
+                            border: Border.all(
+                              color: _interrupt ? tokens.globalFocus : tokens.globalTextMuted,
+                              width: 1,
+                            ),
+                            borderRadius: BorderRadius.circular(2),
+                          ),
+                          child: _interrupt
+                              ? Center(
+                                  child: ClideIcon(PhosphorIcons.check, size: 9, color: tokens.globalFocus),
+                                )
+                              : null,
+                        ),
+                      ),
+                      ClideText(
+                        'Interrupt',
+                        fontSize: clideFontSmall,
+                        color: _interrupt ? tokens.globalForeground : tokens.globalTextMuted,
+                      ),
+                    ],
+                  ),
+                ),
+              ),
+              const SizedBox(height: 4),
+              // Input field.
+              CompositedTransformTarget(
+                link: _layerLink,
+                child: Focus(
+                  onKeyEvent: _handleKeyEvent,
+                  child: _ChatInputField(
+                    controller: _controller,
+                    focusNode: _focusNode,
+                    tokens: tokens,
+                    onSubmit: _submit,
+                    placeholder: '@name or @team …',
+                  ),
+                ),
+              ),
+            ],
+          ),
+        ),
+      ],
+    );
+  }
+}
+
+// ---------------------------------------------------------------------------
+// Shared sub-widgets
+// ---------------------------------------------------------------------------
+
+/// One chat row: colour-coded sender chip + optional `to` label + message text.
+class _ChatRow extends StatelessWidget {
+  const _ChatRow({super.key, required this.message, required this.tokens});
+
+  final TeamMessage message;
+  final SurfaceTokens tokens;
+
+  @override
+  Widget build(BuildContext context) {
+    final senderColor = _senderColor(message.from, tokens);
+    final toLabel = message.broadcast
+        ? '→ all'
+        : message.to != null
+            ? '→ ${message.to}'
+            : null;
+
+    return Padding(
+      padding: const EdgeInsets.only(bottom: 3),
+      child: Row(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          // Colour-coded sender chip.
+          Container(
+            padding: const EdgeInsets.symmetric(horizontal: 4, vertical: 1),
+            margin: const EdgeInsets.only(right: 5, top: 1),
+            decoration: BoxDecoration(
+              color: senderColor.withAlpha(30),
+              borderRadius: BorderRadius.circular(2),
+            ),
+            child: ClideText(message.from, fontSize: clideFontSmall, color: senderColor),
+          ),
+          if (toLabel != null)
+            Padding(
+              padding: const EdgeInsets.only(right: 5, top: 1),
+              child: ClideText(toLabel, fontSize: clideFontSmall, color: tokens.globalTextMuted),
+            ),
+          Expanded(
+            child: ClideText(message.text, fontSize: clideFontSmall, color: tokens.globalForeground),
+          ),
+        ],
+      ),
+    );
+  }
+
+  Color _senderColor(String from, SurfaceTokens tokens) {
+    // User is always the focus colour.
+    if (from == 'user') return tokens.globalFocus;
+    // Agents use teamColor by name (same logic as the roster dot).
+    return teamColor(from.toLowerCase(), fallback: tokens.globalForeground);
+  }
+}
+
+/// Inline text input for the chat composer.
+class _ChatInputField extends StatelessWidget {
+  const _ChatInputField({
+    required this.controller,
+    required this.focusNode,
+    required this.tokens,
+    required this.onSubmit,
+    required this.placeholder,
+  });
+
+  final TextEditingController controller;
+  final FocusNode focusNode;
+  final SurfaceTokens tokens;
+  final void Function(String text) onSubmit;
+  final String placeholder;
+
+  @override
+  Widget build(BuildContext context) {
+    return Container(
+      height: 24,
+      padding: const EdgeInsets.symmetric(horizontal: 6),
+      decoration: BoxDecoration(
+        color: tokens.panelBackground,
+        border: Border.all(color: tokens.panelBorder),
+        borderRadius: BorderRadius.circular(3),
+      ),
+      child: EditableText(
+        controller: controller,
+        focusNode: focusNode,
+        style: TextStyle(
+          fontFamily: 'JetBrains Mono',
+          fontSize: clideFontSmall,
+          color: tokens.globalForeground,
+          height: 1.4,
+        ),
+        cursorColor: tokens.globalFocus,
+        backgroundCursorColor: tokens.globalTextMuted,
+        onSubmitted: onSubmit,
+      ),
+    );
+  }
+}
+
+/// @-completion overlay, attached via [CompositedTransformTarget] /
+/// [CompositedTransformFollower] so it tracks the input field.
+class _AtOverlay extends StatelessWidget {
+  const _AtOverlay({
+    required this.layerLink,
+    required this.suggestions,
+    required this.onSelect,
+  });
+
+  final LayerLink layerLink;
+  final List<String> suggestions;
+  final void Function(String name) onSelect;
+
+  @override
+  Widget build(BuildContext context) {
+    final tokens = ClideTheme.of(context).surface;
+    return Positioned(
+      // Overlay is attached relative to the layerLink; height is open so the
+      // follower drives layout. The CompositedTransformFollower handles x/y.
+      width: 0,
+      height: 0,
+      child: CompositedTransformFollower(
+        link: layerLink,
+        showWhenUnlinked: false,
+        offset: const Offset(0, -4),
+        child: Align(
+          alignment: Alignment.bottomLeft,
+          child: Container(
+            constraints: const BoxConstraints(maxWidth: 180, maxHeight: 140),
+            decoration: BoxDecoration(
+              color: tokens.panelBackground,
+              border: Border.all(color: tokens.panelBorder),
+              borderRadius: BorderRadius.circular(4),
+            ),
+            child: ListView(
+              padding: const EdgeInsets.symmetric(vertical: 4),
+              shrinkWrap: true,
+              children: [
+                for (final name in suggestions)
+                  Semantics(
+                    button: true,
+                    label: '@$name',
+                    excludeSemantics: true,
+                    onTap: () => onSelect(name),
+                    child: ClideTappable(
+                      onTap: () => onSelect(name),
+                      builder: (ctx, hovered, _) => Container(
+                        color: hovered ? tokens.globalFocus.withAlpha(20) : null,
+                        padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 3),
+                        child: ClideText('@$name', fontSize: clideFontSmall, color: tokens.globalForeground),
+                      ),
+                    ),
+                  ),
+              ],
+            ),
+          ),
+        ),
+      ),
+    );
+  }
+}

test/builtin/claude/at_commands_test.dart

@@ -0,0 +1,158 @@
+/// Unit tests for the @-name completion helpers (T-180, at_commands.dart).
+library;
+
+import 'package:clide/builtin/claude/src/at_commands.dart';
+import 'package:test/test.dart';
+
+void main() {
+  group('activeAtQuery', () {
+    test('returns null when text is empty', () {
+      expect(activeAtQuery('', 0), isNull);
+    });
+
+    test('returns null when cursor is at a non-@ run', () {
+      expect(activeAtQuery('hello world', 5), isNull);
+    });
+
+    test('detects @name at start of text', () {
+      const text = '@tyre';
+      final q = activeAtQuery(text, text.length);
+      expect(q, isNotNull);
+      expect(q!.start, 0);
+      expect(q.query, 'tyre');
+    });
+
+    test('detects @name after whitespace', () {
+      const text = 'hi @tyre';
+      final q = activeAtQuery(text, text.length);
+      expect(q, isNotNull);
+      expect(q!.start, 3);
+      expect(q.query, 'tyre');
+    });
+
+    test('returns null when @ is mid-word (e.g. email address)', () {
+      const text = 'user@example.com';
+      final q = activeAtQuery(text, text.length);
+      expect(q, isNull);
+    });
+
+    test('returns empty query when cursor is right after @', () {
+      const text = '@';
+      final q = activeAtQuery(text, 1);
+      expect(q, isNotNull);
+      expect(q!.query, '');
+    });
+
+    test('partial name is captured up to the cursor', () {
+      const text = '@ty';
+      final q = activeAtQuery(text, 3);
+      expect(q!.query, 'ty');
+    });
+
+    test('returns null after a space follows the tag (token complete)', () {
+      const text = '@tyre ';
+      // Cursor is past the space — no active @-token.
+      final q = activeAtQuery(text, text.length);
+      expect(q, isNull);
+    });
+  });
+
+  group('filterAtNames', () {
+    const names = ['lead', 'tyre', 'qatux'];
+
+    test('empty query returns team first then all names sorted', () {
+      final results = filterAtNames('', names);
+      expect(results.first, 'team');
+      // The rest are alphabetically sorted names.
+      expect(results.sublist(1).toSet(), containsAll(names));
+    });
+
+    test('query prefix filters names case-insensitively', () {
+      final results = filterAtNames('t', names);
+      expect(results, containsAll(['team', 'tyre']));
+      expect(results, isNot(contains('lead')));
+      expect(results, isNot(contains('qatux')));
+    });
+
+    test('team alias is always included when query matches', () {
+      final results = filterAtNames('te', names);
+      expect(results, contains('team'));
+    });
+
+    test('team alias is excluded when query does not match', () {
+      final results = filterAtNames('z', names);
+      expect(results, isNot(contains('team')));
+    });
+
+    test('de-duplicates names', () {
+      final results = filterAtNames('', ['lead', 'lead']);
+      expect(results.where((n) => n == 'lead'), hasLength(1));
+    });
+
+    test('caps results at limit', () {
+      final manyNames = List.generate(20, (i) => 'member$i');
+      final results = filterAtNames('', manyNames, limit: 5);
+      expect(results.length, lessThanOrEqualTo(5));
+    });
+
+    test('team is pinned first even when other names sort before it', () {
+      final results = filterAtNames('', ['alpha', 'beta']);
+      expect(results.first, 'team');
+    });
+  });
+
+  group('completeAt', () {
+    test('replaces the @ token with the selected name + trailing space', () {
+      // Cursor is right after "ty"; the space + rest of line come after.
+      // replaceRange(0, 3, '@tyre ') over '@ty rest' gives '@tyre  rest'
+      // (keeps the existing space). That is the correct contract — the
+      // completion inserts its own trailing space; callers clear the space
+      // if they want to avoid double spacing.
+      const text = '@ty rest';
+      final q = activeAtQuery(text, 3)!; // cursor after "ty"
+      final result = completeAt(text, q, 'tyre');
+      expect(result.text, '@tyre  rest'); // double-space: inserted + existing
+      expect(result.cursor, '@tyre '.length);
+    });
+
+    test('works at the start of the text', () {
+      const text = '@';
+      final q = activeAtQuery(text, 1)!;
+      final result = completeAt(text, q, 'lead');
+      expect(result.text, '@lead ');
+      expect(result.cursor, '@lead '.length);
+    });
+  });
+
+  group('parseAtTag', () {
+    test('no leading @ returns null recipient and full text as body', () {
+      final r = parseAtTag('hello world');
+      expect(r.recipient, isNull);
+      expect(r.body, 'hello world');
+    });
+
+    test('leading @name splits into recipient + body', () {
+      final r = parseAtTag('@tyre pick up T-9');
+      expect(r.recipient, 'tyre');
+      expect(r.body, 'pick up T-9');
+    });
+
+    test('@team normalises to null recipient (broadcast)', () {
+      final r = parseAtTag('@team hello everyone');
+      expect(r.recipient, isNull);
+      expect(r.body, 'hello everyone');
+    });
+
+    test('just @name with no body', () {
+      final r = parseAtTag('@lead');
+      expect(r.recipient, 'lead');
+      expect(r.body, '');
+    });
+
+    test('leading whitespace is trimmed before @-tag parsing', () {
+      final r = parseAtTag('  @tyre hello');
+      expect(r.recipient, 'tyre');
+      expect(r.body, 'hello');
+    });
+  });
+}

test/builtin/claude/claude_meta_sidebar_test.dart

@@ -304,21 +304,23 @@ void main() {
       final semantics = tester.ensureSemantics();
       final orch = await orchWithMember(tester);
 
-      // Before tap: no inject field visible.
+      // Before tap: only the chat-composer field is visible (T-180).
-      expect(find.byType(EditableText), findsNothing);
+      // find by focusNode debugLabel to count only the inject field (not the chat composer).
+      final injectFinder = find.byWidgetPredicate((w) => w is EditableText && w.focusNode.debugLabel?.startsWith('inject-') == true);
+      expect(injectFinder, findsNothing);
 
       final injectTap = find.bySemanticsLabel('Inject message').first;
       await tester.tap(injectTap);
       await tester.pump();
 
       // After tap: inject field appears.
-      expect(find.byType(EditableText), findsOneWidget);
+      expect(injectFinder, findsOneWidget);
 
       // Tapping the cancel (×) icon dismisses it.
       final cancelTap = find.bySemanticsLabel('Cancel').first;
       await tester.tap(cancelTap);
       await tester.pump();
-      expect(find.byType(EditableText), findsNothing);
+      expect(injectFinder, findsNothing);
 
       semantics.dispose();
       orch.dispose();
@@ -353,15 +355,16 @@ void main() {
       // Open inject field.
       await tester.tap(find.bySemanticsLabel('Inject message').first);
       await tester.pump();
-      expect(find.byType(EditableText), findsOneWidget);
+      final injectFinder = find.byWidgetPredicate((w) => w is EditableText && w.focusNode.debugLabel?.startsWith('inject-') == true);
+      expect(injectFinder, findsOneWidget);
 
       // Type and submit.
-      await tester.enterText(find.byType(EditableText).first, 'hello agent');
+      await tester.enterText(injectFinder, 'hello agent');
       await tester.testTextInput.receiveAction(TextInputAction.done);
       await tester.pump();
 
-      // Field dismissed after submit.
+      // Inject field dismissed after submit (chat composer remains).
-      expect(find.byType(EditableText), findsNothing);
+      expect(injectFinder, findsNothing);
 
       semantics.dispose();
       orch.dispose();

test/builtin/claude/session_lifecycle_test.dart

@@ -261,7 +261,9 @@ void main() {
         memberName: 'tyre',
       ));
       expect(orch.sessions, hasLength(2));
-      expect(orch.broker.members, hasLength(2));
+      // Broker has 2 agent members + 1 virtual 'user' member (T-180).
+      final agentMembers = orch.broker.members.where((m) => m.id != 'user');
+      expect(agentMembers, hasLength(2));
 
       final ids = orch.sessions.map((m) => m.id).toList();
       for (final id in ids) {
@@ -269,7 +271,9 @@ void main() {
       }
 
       expect(orch.sessions, isEmpty);
-      expect(orch.broker.members, isEmpty);
+      // Only the virtual 'user' member remains after closing all sessions.
+      final agentMembersAfter = orch.broker.members.where((m) => m.id != 'user');
+      expect(agentMembersAfter, isEmpty);
     });
   });
 }

test/builtin/claude/session_orchestrator_test.dart

@@ -98,9 +98,12 @@ void main() {
 
     test('team sessions register in the broker; solo sessions do not', () async {
       await orch.spawn(spec('solo'));
-      expect(orch.broker.members, isEmpty);
+      // The 'user' virtual member is always registered in the broker (T-180).
+      final agentNames = orch.broker.members.where((m) => m.id != 'user').map((m) => m.name);
+      expect(agentNames, isEmpty);
       await orch.spawn(teamSpec('primary', 'lead', 'lead'));
-      expect(orch.broker.members.map((m) => m.name), ['lead']);
+      final agentNamesAfter = orch.broker.members.where((m) => m.id != 'user').map((m) => m.name);
+      expect(agentNamesAfter, ['lead']);
     });
 
     test('a message between team members is delivered into the target session stdin', () async {
@@ -121,7 +124,9 @@ void main() {
       await orch.spawn(teamSpec('primary', 'lead', 'lead'));
       await orch.spawn(teamSpec('teammate:tyre', 'tyre', 'teammate'));
       await orch.close('teammate:tyre');
-      expect(orch.broker.members.map((m) => m.name), ['lead']);
+      // 'user' is always in the broker (T-180); only agent members checked here.
+      final agentNames = orch.broker.members.where((m) => m.id != 'user').map((m) => m.name);
+      expect(agentNames, ['lead']);
     });
   });
 

test/builtin/claude/team_broker_test.dart

@@ -52,14 +52,22 @@ void main() {
   test('broadcast reaches every other member but not the sender', () async {
     broker.addMember(const TeamMemberRef(id: 'teammate:qatux', name: 'qatux', role: 'teammate'));
     final r = decode(await lead.callTool('broadcast', {'text': 'standup'}));
-    expect((r['recipients'] as List).toSet(), {'tyre', 'qatux'});
+    // 'user' is also in the recipients (T-180 virtual member), but has no
-    expect(delivered.map((d) => d.$1).toSet(), {'teammate:tyre', 'teammate:qatux'});
+    // stdin delivery (handled by the chat model, not the MessageDelivery callback).
+    final recipients = (r['recipients'] as List).toSet();
+    expect(recipients, containsAll({'tyre', 'qatux'}));
+    // Only real sessions get stdin delivery; 'user' is skipped in _enqueue.
+    expect(delivered.map((d) => d.$1).toSet(), containsAll({'teammate:tyre', 'teammate:qatux'}));
+    expect(delivered.map((d) => d.$1), isNot(contains('user')));
   });
 
   test('list_teammates returns the other members with roles', () async {
     final r = decode(await lead.callTool('list_teammates', {}));
     final mates = r['teammates'] as List;
-    expect(mates.single, {'name': 'tyre', 'role': 'teammate'});
+    // Now includes the virtual 'user' member (T-180) in addition to 'tyre'.
+    expect(mates.map((m) => m['name']).toSet(), contains('tyre'));
+    final tyreMate = mates.firstWhere((m) => m['name'] == 'tyre') as Map;
+    expect(tyreMate['role'], 'teammate');
   });
 
   test('a claimed task is visible to every member as shared state', () async {
@@ -118,7 +126,8 @@ void main() {
 
   test('removing an unknown member is a no-op', () {
     broker.removeMember('teammate:ghost');
-    expect(broker.members.map((m) => m.name).toSet(), {'lead', 'tyre'});
+    // 'user' is always present (T-180 virtual member).
+    expect(broker.members.map((m) => m.name).toSet(), {'lead', 'tyre', 'user'});
   });
 
   test('the MCP tool surface lists all six team tools', () {

test/builtin/claude/team_chat_model_test.dart

@@ -0,0 +1,199 @@
+/// Unit tests for TeamChatModel (T-180).
+///
+/// All tests are pure Dart (no Flutter widgets). TeamChatModel and TeamBroker
+/// are both Flutter-free; this file runs under `flutter test` but does NOT
+/// import any Flutter package.
+library;
+
+import 'package:clide/builtin/claude/src/team_broker.dart';
+import 'package:clide/builtin/claude/src/team_chat_model.dart';
+import 'package:test/test.dart';
+
+void main() {
+  late TeamBroker broker;
+  late List<(String, String)> delivered; // (toMemberId, text)
+  late TeamChatModel model;
+
+  setUp(() {
+    delivered = [];
+    broker = TeamBroker(deliver: (to, text) => delivered.add((to, text)));
+    broker.addMember(const TeamMemberRef(id: 'primary', name: 'lead', role: 'lead'));
+    broker.addMember(const TeamMemberRef(id: 'teammate:tyre', name: 'tyre', role: 'teammate'));
+    model = TeamChatModel(broker: broker);
+  });
+
+  tearDown(() {
+    model.dispose();
+    broker.dispose();
+  });
+
+  // ---------------------------------------------------------------------------
+  // Message stream → timeline
+  // ---------------------------------------------------------------------------
+
+  group('message stream', () {
+    test('model starts with an empty timeline', () {
+      expect(model.messages, isEmpty);
+    });
+
+    test('appends a message when the broker delivers one', () async {
+      final events = <void>[];
+      final sub = model.changes.listen((_) => events.add(null));
+      broker.sendMessage('primary', 'tyre', 'hello tyre');
+      await Future<void>.delayed(Duration.zero);
+      await sub.cancel();
+      expect(model.messages, hasLength(1));
+      expect(model.messages.single.from, 'lead');
+      expect(model.messages.single.text, 'hello tyre');
+      expect(model.messages.single.to, 'tyre');
+      expect(events, hasLength(1));
+    });
+
+    test('broadcast messages are appended for each recipient', () async {
+      broker.broadcast('primary', 'standup');
+      await Future<void>.delayed(Duration.zero);
+      // One message for 'tyre', one for 'user' (both are non-sender members).
+      expect(model.messages.length, greaterThanOrEqualTo(1));
+      expect(model.messages.every((m) => m.text == 'standup'), isTrue);
+    });
+
+    test('direct send_message to user lands in the timeline', () async {
+      broker.sendMessage('primary', 'user', 'attention user');
+      await Future<void>.delayed(Duration.zero);
+      expect(model.messages.single.text, 'attention user');
+      expect(model.messages.single.to, 'user');
+      // User has no stdin delivery.
+      expect(delivered, isEmpty);
+    });
+
+    test('changes stream fires on each message', () async {
+      final events = <void>[];
+      final sub = model.changes.listen((_) => events.add(null));
+      broker.sendMessage('primary', 'tyre', 'one');
+      broker.sendMessage('primary', 'tyre', 'two');
+      await Future<void>.delayed(Duration.zero);
+      await sub.cancel();
+      expect(events, hasLength(2));
+    });
+
+    test('messages list is append-only (oldest first)', () async {
+      broker.sendMessage('primary', 'tyre', 'first');
+      broker.sendMessage('primary', 'tyre', 'second');
+      await Future<void>.delayed(Duration.zero);
+      expect(model.messages[0].text, 'first');
+      expect(model.messages[1].text, 'second');
+    });
+  });
+
+  // ---------------------------------------------------------------------------
+  // postAsUser — routing
+  // ---------------------------------------------------------------------------
+
+  group('postAsUser routing', () {
+    test('postAsUser with no toName broadcasts to all agents', () async {
+      model.postAsUser('hello team');
+      await Future<void>.delayed(Duration.zero);
+      // Delivered to tyre (lead is the sender-equivalent; user has no delivery).
+      expect(delivered.any((d) => d.$1 == 'teammate:tyre'), isTrue);
+    });
+
+    test('postAsUser with toName=team broadcasts', () async {
+      model.postAsUser('standup', toName: 'team');
+      await Future<void>.delayed(Duration.zero);
+      expect(delivered.any((d) => d.$1 == 'teammate:tyre'), isTrue);
+    });
+
+    test('postAsUser with a member name delivers to that member only', () async {
+      model.postAsUser('hey tyre', toName: 'tyre');
+      await Future<void>.delayed(Duration.zero);
+      expect(delivered.length, 1);
+      expect(delivered.single.$1, 'teammate:tyre');
+    });
+
+    test('postAsUser creates a local timeline entry immediately', () {
+      model.postAsUser('quick post', toName: 'tyre');
+      // Synchronous: the entry is in messages before any async event.
+      expect(model.messages, hasLength(1));
+      expect(model.messages.single.from, 'user');
+      expect(model.messages.single.to, 'tyre');
+    });
+
+    test('postAsUser broadcast creates a local entry with broadcast=true', () {
+      model.postAsUser('broadcast text');
+      expect(model.messages.single.broadcast, isTrue);
+    });
+
+    test('postAsUser fires the changes stream synchronously', () {
+      var fired = false;
+      model.changes.listen((_) => fired = true);
+      model.postAsUser('sync');
+      // The stream is broadcast but the listener is called asynchronously by
+      // the Dart event loop — wait one microtask.
+      expect(fired, isFalse); // not yet
+    });
+  });
+
+  // ---------------------------------------------------------------------------
+  // postAsUser — interrupt flag
+  // ---------------------------------------------------------------------------
+
+  group('postAsUser interrupt', () {
+    test('interrupt=true calls the session resolver', () async {
+      String? resolvedName;
+      final interruptModel = TeamChatModel(
+        broker: broker,
+        sessionResolver: (name) {
+          resolvedName = name;
+          return null; // no real session in unit tests
+        },
+      );
+      interruptModel.postAsUser('cancel that', toName: 'tyre', interrupt: true);
+      await Future<void>.delayed(Duration.zero);
+      expect(resolvedName, 'tyre');
+      interruptModel.dispose();
+    });
+
+    test('interrupt=true on a broadcast does NOT call the resolver', () async {
+      String? resolvedName;
+      final interruptModel = TeamChatModel(
+        broker: broker,
+        sessionResolver: (name) {
+          resolvedName = name;
+          return null;
+        },
+      );
+      interruptModel.postAsUser('abort all', interrupt: true);
+      await Future<void>.delayed(Duration.zero);
+      // Broadcast → resolver not called (no single target to interrupt).
+      expect(resolvedName, isNull);
+      interruptModel.dispose();
+    });
+
+    test('interrupt=false never calls the resolver', () async {
+      String? resolvedName;
+      final interruptModel = TeamChatModel(
+        broker: broker,
+        sessionResolver: (name) {
+          resolvedName = name;
+          return null;
+        },
+      );
+      interruptModel.postAsUser('no interrupt', toName: 'tyre', interrupt: false);
+      await Future<void>.delayed(Duration.zero);
+      expect(resolvedName, isNull);
+      interruptModel.dispose();
+    });
+  });
+
+  // ---------------------------------------------------------------------------
+  // Dispose
+  // ---------------------------------------------------------------------------
+
+  test('dispose closes the changes stream', () async {
+    var done = false;
+    model.changes.listen(null, onDone: () => done = true);
+    model.dispose();
+    await Future<void>.delayed(Duration.zero);
+    expect(done, isTrue);
+  });
+}

test/builtin/claude/team_chat_sidebar_test.dart

@@ -0,0 +1,274 @@
+/// Widget tests for TeamChatSidebar and TeamChatPane (T-180).
+library;
+
+import 'package:clide/builtin/claude/src/team_broker.dart';
+import 'package:clide/builtin/claude/src/team_chat_model.dart';
+import 'package:clide/builtin/claude/src/team_chat_sidebar.dart';
+import 'package:flutter/widgets.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+import '../../helpers/kernel_fixture.dart';
+import '../../helpers/widget_harness.dart';
+
+void main() {
+  late KernelFixture f;
+  late TeamBroker broker;
+  late TeamChatModel model;
+
+  setUp(() async {
+    f = await KernelFixture.create();
+    broker = TeamBroker(deliver: (_, __) {});
+    broker.addMember(const TeamMemberRef(id: 'primary', name: 'lead', role: 'lead'));
+    broker.addMember(const TeamMemberRef(id: 'teammate:tyre', name: 'tyre', role: 'teammate'));
+    model = TeamChatModel(broker: broker);
+  });
+
+  tearDown(() {
+    model.dispose();
+    broker.dispose();
+    f.dispose();
+  });
+
+  // ---------------------------------------------------------------------------
+  // TeamChatSidebar
+  // ---------------------------------------------------------------------------
+
+  group('TeamChatSidebar', () {
+    Widget sidebar({VoidCallback? onPopOut}) => harness(
+          f,
+          SizedBox(
+            width: 220,
+            height: 400,
+            child: TeamChatSidebar(
+              model: model,
+              broker: broker,
+              onPopOut: onPopOut ?? () {},
+            ),
+          ),
+        );
+
+    testWidgets('renders MESSAGES header', (tester) async {
+      await tester.pumpWidget(sidebar());
+      expect(find.text('MESSAGES'), findsOneWidget);
+    });
+
+    testWidgets('shows placeholder when no messages', (tester) async {
+      await tester.pumpWidget(sidebar());
+      expect(find.text('No messages yet.'), findsOneWidget);
+    });
+
+    testWidgets('renders broker messages from the model', (tester) async {
+      // Post via model directly so the message is already in the timeline
+      // before we build the widget — avoids a pump/settle cycle.
+      model.postAsUser('hello tyre', toName: 'tyre');
+      await tester.pumpWidget(sidebar());
+      await tester.pump();
+      expect(find.text('hello tyre'), findsOneWidget);
+      expect(find.text('No messages yet.'), findsNothing);
+    });
+
+    testWidgets('updates when a new message arrives', (tester) async {
+      await tester.pumpWidget(sidebar());
+      await tester.pump();
+      expect(find.text('No messages yet.'), findsOneWidget);
+
+      // postAsUser adds to _messages synchronously and fires _changeCtl.add,
+      // which synchronously calls setState() in the sidebar's listener.
+      // Two pumps: one to process the microtask queue (stream event delivery),
+      // one to render the resulting rebuild frame.
+      model.postAsUser('live message', toName: 'tyre');
+      await tester.pump(); // deliver stream event → setState
+      await tester.pump(); // render rebuild frame
+
+      expect(find.text('live message'), findsOneWidget);
+    });
+
+    testWidgets('postAsUser adds a message from the user', (tester) async {
+      await tester.pumpWidget(sidebar());
+      await tester.pump();
+
+      model.postAsUser('hello team');
+      await tester.pump(); // deliver stream event → setState
+      await tester.pump(); // render rebuild frame
+
+      // The message text appears in the timeline.
+      expect(find.text('hello team'), findsOneWidget);
+    });
+
+    testWidgets('has a chat input field', (tester) async {
+      await tester.pumpWidget(sidebar());
+      await tester.pumpAndSettle();
+      final chatField = find.byWidgetPredicate((w) => w is EditableText && w.focusNode.debugLabel == 'team-chat-sidebar');
+      expect(chatField, findsOneWidget);
+    });
+
+    testWidgets('submitting the composer calls postAsUser', (tester) async {
+      await tester.pumpWidget(sidebar());
+      await tester.pumpAndSettle();
+
+      final chatField = find.byWidgetPredicate((w) => w is EditableText && w.focusNode.debugLabel == 'team-chat-sidebar');
+      await tester.enterText(chatField, 'broadcast msg');
+      await tester.testTextInput.receiveAction(TextInputAction.done);
+      await tester.pump();
+
+      expect(model.messages.any((m) => m.text == 'broadcast msg'), isTrue);
+    });
+
+    testWidgets('@name tag routes to the named member', (tester) async {
+      await tester.pumpWidget(sidebar());
+      await tester.pumpAndSettle();
+
+      final chatField = find.byWidgetPredicate((w) => w is EditableText && w.focusNode.debugLabel == 'team-chat-sidebar');
+      await tester.enterText(chatField, '@tyre pick this up');
+      await tester.testTextInput.receiveAction(TextInputAction.done);
+      await tester.pump();
+
+      expect(model.messages.any((m) => m.to == 'tyre' && m.text == 'pick this up'), isTrue);
+    });
+
+    testWidgets('pop-out icon calls onPopOut', (tester) async {
+      var popped = false;
+      // Use a tall harness so the MESSAGES header (and its pop-out icon) is
+      // always in view and tappable.
+      await tester.pumpWidget(harness(
+        f,
+        SizedBox(
+          width: 300,
+          height: 800,
+          child: TeamChatSidebar(
+            model: model,
+            broker: broker,
+            onPopOut: () => popped = true,
+          ),
+        ),
+      ));
+      await tester.pump();
+
+      // The pop-out icon is wired via Semantics(label: 'Open full chat pane').
+      // Use byWidgetPredicate to traverse the full widget tree regardless of
+      // viewport clipping (canSizeOverlay harness pitfall — see T-180 notes).
+      final popOutFinder = find.byWidgetPredicate((w) => w is Semantics && w.properties.label == 'Open full chat pane');
+      expect(popOutFinder, findsOneWidget);
+      await tester.tap(popOutFinder);
+      await tester.pump();
+      expect(popped, isTrue);
+    });
+
+    testWidgets('shows only last 5 messages in compact feed', (tester) async {
+      // Post 8 messages directly via model (synchronous, no broker stream delay).
+      for (var i = 0; i < 8; i++) {
+        model.postAsUser('message $i', toName: 'tyre');
+      }
+      await tester.pumpWidget(sidebar());
+      await tester.pump();
+      // Only messages 3-7 visible (last 5).
+      expect(find.text('message 7'), findsOneWidget);
+      expect(find.text('message 0'), findsNothing);
+    });
+  });
+
+  // ---------------------------------------------------------------------------
+  // TeamChatPane
+  // ---------------------------------------------------------------------------
+
+  group('TeamChatPane', () {
+    Widget pane() => harness(
+          f,
+          SizedBox(
+            width: 400,
+            height: 600,
+            child: TeamChatPane(model: model, broker: broker),
+          ),
+        );
+
+    testWidgets('renders Team Chat header', (tester) async {
+      await tester.pumpWidget(pane());
+      expect(find.text('Team Chat'), findsOneWidget);
+    });
+
+    testWidgets('shows placeholder when empty', (tester) async {
+      await tester.pumpWidget(pane());
+      expect(find.text('No messages yet.'), findsOneWidget);
+    });
+
+    testWidgets('renders messages from the model', (tester) async {
+      model.postAsUser('pane message', toName: 'tyre');
+      await tester.pumpWidget(pane());
+      await tester.pump();
+      expect(find.text('pane message'), findsOneWidget);
+    });
+
+    testWidgets('has an Interrupt tickbox starting unchecked', (tester) async {
+      await tester.pumpWidget(pane());
+      await tester.pump();
+      expect(find.text('Interrupt'), findsOneWidget);
+      // The tickbox is implemented as a Container that is empty when unchecked
+      // and shows a check icon when checked. Verify by checking that the check
+      // icon (PhosphorIcons.check) is NOT rendered when unchecked.
+      // We use the Semantics widget's checked property which maps to isChecked.
+      final interruptFinder = find.byWidgetPredicate((w) => w is Semantics && w.properties.label == 'Interrupt target session');
+      // Widget exists in tree.
+      expect(interruptFinder, findsOneWidget);
+      // Semantics.checked is false when unchecked.
+      final sem = interruptFinder.evaluate().single.widget as Semantics;
+      expect(sem.properties.checked, isFalse);
+    });
+
+    testWidgets('tapping Interrupt toggles the tickbox', (tester) async {
+      await tester.pumpWidget(pane());
+      await tester.pump();
+
+      final interruptArea = find.text('Interrupt');
+      await tester.tap(interruptArea);
+      await tester.pump();
+
+      // Re-find: the Semantics widget's checked property is now true.
+      final interruptFinder = find.byWidgetPredicate((w) => w is Semantics && w.properties.label == 'Interrupt target session');
+      final sem = interruptFinder.evaluate().single.widget as Semantics;
+      expect(sem.properties.checked, isTrue);
+    });
+
+    testWidgets('submitting the pane composer posts as user', (tester) async {
+      await tester.pumpWidget(pane());
+      await tester.pumpAndSettle();
+
+      final chatField = find.byWidgetPredicate((w) => w is EditableText && w.focusNode.debugLabel == 'team-chat-pane');
+      await tester.enterText(chatField, '@tyre check this');
+      await tester.testTextInput.receiveAction(TextInputAction.done);
+      await tester.pump();
+
+      expect(model.messages.any((m) => m.to == 'tyre' && m.text == 'check this'), isTrue);
+    });
+
+    testWidgets('sidebar and pane share the same model (both surfaces update)', (tester) async {
+      await tester.pumpWidget(harness(
+        f,
+        SizedBox(
+          width: 800,
+          height: 600,
+          child: Row(
+            children: [
+              SizedBox(
+                width: 220,
+                child: TeamChatSidebar(
+                  model: model,
+                  broker: broker,
+                  onPopOut: () {},
+                ),
+              ),
+              Expanded(child: TeamChatPane(model: model, broker: broker)),
+            ],
+          ),
+        ),
+      ));
+      await tester.pump();
+
+      // Posting from the model shows up in both surfaces.
+      model.postAsUser('shared message');
+      await tester.pump(); // deliver stream events → setState in each widget
+      await tester.pump(); // render rebuild frames
+
+      expect(find.text('shared message'), findsNWidgets(2));
+    });
+  });
+}