diff --git a/frontend/CLAUDE.md b/frontend/CLAUDE.md
index 7e9c400..f98408b 100644
--- a/frontend/CLAUDE.md
+++ b/frontend/CLAUDE.md
@@ -32,7 +32,7 @@ informatics/                DataManager · AppDataManager
 memory/                     ConnectInternalMemory · InternalMemory
 configs/                    Navigator · Env · NotificationServiceConfig
 designs/                    Component · Shell · Responsive · buttons/ input/ text/
-see/<feature>/              screens, 4 files each
+see/<feature>/              screens, 4 files each (group/ = groups, shared goals, chat)
 utils/                      Colors · CommonUtils · engines · validators
 ```
 
diff --git a/frontend/design.md b/frontend/design.md
index f8ad7d1..76b8829 100644
--- a/frontend/design.md
+++ b/frontend/design.md
@@ -88,5 +88,24 @@ minutes held against planned, a ring with + that opens the "Add to today"
 sheet, the plan as thumbnails, the report-card letter as the Score, and one
 bar per commitment class. Weekly swaps in the week's average, a bar per day
 and the class completion rates. Below the block, on the light ambient
-surface: the water tracker (drops of 250 ml, kept on the device), then the
-rest of the day. Bars on the dark block use the `colorBar*` tokens.
+surface: the rest of the day. Bars on the dark block use the `colorBar*` tokens.
+
+## Groups
+
+`see/group/`: people keeping each other honest. A group has members, shared
+goals and a chat.
+
+- **Shared goals** are split into **objectives** with a number and a unit
+  (200 km, 40 runs, 30,000 words). Every member logs toward them; the card
+  shows the group total, your share and a night **Log** button. Like
+  personal goals, they carry no debt.
+- **Leaderboard** ranks members by kept rate over the last 7 days, with
+  streak, last check-in (red "quiet" after 24h) and a nudge button.
+- **Chat** keeps the work and the talk together: plain messages are square
+  bubbles (yours in night, others white with the author's colour), while
+  check-ins (green bar) and nudges (amber bar) are cards in the thread.
+  The open chat polls every 4 seconds.
+- Members are drawn by `memberAvatar` / `avatarStack`
+  (`designs/MemberAvatar.dart`): square painted portraits with the initial.
+- Groups are reached from the nav (Groups tab), the Home "Your groups" rail
+  (tap opens the chat) and the add sheet.
diff --git a/frontend/lib/Grounded/about/external/data/Group.dart b/frontend/lib/Grounded/about/external/data/Group.dart
new file mode 100644
index 0000000..cbba18e
--- /dev/null
+++ b/frontend/lib/Grounded/about/external/data/Group.dart
@@ -0,0 +1,94 @@
+import '../../../utils/ObjectConvertors.dart';
+import 'GroupGoal.dart';
+import 'GroupMember.dart';
+
+/// People keeping each other honest: members, the goals they share, and the
+/// chat they talk in.
+class Group {
+  String id;
+
+  String name;
+
+  String description;
+
+  String colourHex;
+
+  /// Six characters a friend types to join.
+  String inviteCode;
+
+  List<GroupMember> members;
+
+  List<GroupGoal> goals;
+
+  /// Messages the signed-in user has not seen yet.
+  int unread;
+
+  String lastMessage;
+
+  String lastAuthor;
+
+  DateTime? lastMessageAt;
+
+  Group({
+    this.id = "",
+    this.name = "",
+    this.description = "",
+    this.colourHex = "",
+    this.inviteCode = "",
+    List<GroupMember>? members,
+    List<GroupGoal>? goals,
+    this.unread = 0,
+    this.lastMessage = "",
+    this.lastAuthor = "",
+    this.lastMessageAt,
+  })  : members = members ?? <GroupMember>[],
+        goals = goals ?? <GroupGoal>[];
+
+  /// Average progress across the shared goals.
+  double get progress {
+    if (goals.isEmpty) {
+      return 0;
+    }
+    double total = 0;
+    for (GroupGoal goal in goals) {
+      total = total + goal.progress;
+    }
+    return total / goals.length;
+  }
+
+  bool get iOwn => members.any((member) => member.me && member.owner);
+
+  factory Group.fromJson(Map<String, dynamic> json) {
+    return Group(
+      id: json['id'] ?? "",
+      name: json['name'] ?? "",
+      description: json['description'] ?? "",
+      colourHex: json['colourHex'] ?? "",
+      inviteCode: json['inviteCode'] ?? "",
+      members: getGroupMemberList(json['members']),
+      goals: getGroupGoalList(json['goals']),
+      unread: json['unread'] ?? 0,
+      lastMessage: json['lastMessage'] ?? "",
+      lastAuthor: json['lastAuthor'] ?? "",
+      lastMessageAt: json['lastMessageAt'] == null
+          ? null
+          : DateTime.tryParse(json['lastMessageAt']),
+    );
+  }
+
+  Map<String, dynamic> toJson() {
+    final Map<String, dynamic> data = <String, dynamic>{};
+    data['id'] = id;
+    data['name'] = name;
+    data['description'] = description;
+    data['colourHex'] = colourHex;
+    data['inviteCode'] = inviteCode;
+    data['members'] = members.map((item) => item.toJson()).toList();
+    data['goals'] = goals.map((item) => item.toJson()).toList();
+    data['unread'] = unread;
+    data['lastMessage'] = lastMessage;
+    data['lastAuthor'] = lastAuthor;
+    data['lastMessageAt'] = lastMessageAt?.toIso8601String();
+    return data;
+  }
+}
diff --git a/frontend/lib/Grounded/about/external/data/GroupGoal.dart b/frontend/lib/Grounded/about/external/data/GroupGoal.dart
new file mode 100644
index 0000000..b2ed8ab
--- /dev/null
+++ b/frontend/lib/Grounded/about/external/data/GroupGoal.dart
@@ -0,0 +1,67 @@
+import '../../../utils/ObjectConvertors.dart';
+import 'GroupObjective.dart';
+
+/// A goal the whole group shares, broken into objectives everyone logs
+/// against. Like a personal goal it carries no debt of its own.
+class GroupGoal {
+  String id;
+
+  String title;
+
+  String description;
+
+  DateTime? targetDate;
+
+  String colourHex;
+
+  List<GroupObjective> objectives;
+
+  GroupGoal({
+    this.id = "",
+    this.title = "",
+    this.description = "",
+    this.targetDate,
+    this.colourHex = "",
+    List<GroupObjective>? objectives,
+  }) : objectives = objectives ?? <GroupObjective>[];
+
+  /// The average of the objectives, so one runaway objective cannot carry
+  /// the rest.
+  double get progress {
+    if (objectives.isEmpty) {
+      return 0;
+    }
+    double total = 0;
+    for (GroupObjective objective in objectives) {
+      total = total + objective.progress;
+    }
+    return total / objectives.length;
+  }
+
+  int get completeObjectives =>
+      objectives.where((objective) => objective.complete).length;
+
+  factory GroupGoal.fromJson(Map<String, dynamic> json) {
+    return GroupGoal(
+      id: json['id'] ?? "",
+      title: json['title'] ?? "",
+      description: json['description'] ?? "",
+      targetDate: json['targetDate'] == null || json['targetDate'] == ""
+          ? null
+          : DateTime.tryParse(json['targetDate']),
+      colourHex: json['colourHex'] ?? "",
+      objectives: getGroupObjectiveList(json['objectives']),
+    );
+  }
+
+  Map<String, dynamic> toJson() {
+    final Map<String, dynamic> data = <String, dynamic>{};
+    data['id'] = id;
+    data['title'] = title;
+    data['description'] = description;
+    data['targetDate'] = targetDate?.toIso8601String();
+    data['colourHex'] = colourHex;
+    data['objectives'] = objectives.map((item) => item.toJson()).toList();
+    return data;
+  }
+}
diff --git a/frontend/lib/Grounded/about/external/data/GroupMember.dart b/frontend/lib/Grounded/about/external/data/GroupMember.dart
new file mode 100644
index 0000000..efb16bb
--- /dev/null
+++ b/frontend/lib/Grounded/about/external/data/GroupMember.dart
@@ -0,0 +1,64 @@
+/// Someone in a group, with the numbers the leaderboard ranks on.
+class GroupMember {
+  String id;
+
+  String name;
+
+  /// "Owner" or "Member".
+  String role;
+
+  /// Share of their own commitments kept over the last seven days, 0..1.
+  double keptRate;
+
+  /// Kept days in a row.
+  int streak;
+
+  /// Their standing name — Good, Warned, Grounded, Lockdown.
+  String standing;
+
+  DateTime? lastCheckIn;
+
+  /// True for the signed-in user.
+  bool me;
+
+  GroupMember({
+    this.id = "",
+    this.name = "",
+    this.role = "Member",
+    this.keptRate = 0,
+    this.streak = 0,
+    this.standing = "Good",
+    this.lastCheckIn,
+    this.me = false,
+  });
+
+  bool get owner => role == "Owner";
+
+  factory GroupMember.fromJson(Map<String, dynamic> json) {
+    return GroupMember(
+      id: json['id'] ?? "",
+      name: json['name'] ?? "",
+      role: json['role'] ?? "Member",
+      keptRate: (json['keptRate'] ?? 0).toDouble(),
+      streak: json['streak'] ?? 0,
+      standing: json['standing'] ?? "Good",
+      lastCheckIn: json['lastCheckIn'] == null
+          ? null
+          : DateTime.tryParse(json['lastCheckIn']),
+      me: json['me'] ?? false,
+    );
+  }
+
+  Map<String, dynamic> toJson() {
+    final Map<String, dynamic> data = <String, dynamic>{};
+    data['id'] = id;
+    data['name'] = name;
+    data['role'] = role;
+    data['keptRate'] = keptRate;
+    data['streak'] = streak;
+    data['standing'] = standing;
+    data['lastCheckIn'] = lastCheckIn?.toIso8601String();
+    data['me'] = me;
+    return data;
+  }
+}
diff --git a/frontend/lib/Grounded/about/external/data/GroupMessage.dart b/frontend/lib/Grounded/about/external/data/GroupMessage.dart
new file mode 100644
index 0000000..eb7922c
--- /dev/null
+++ b/frontend/lib/Grounded/about/external/data/GroupMessage.dart
@@ -0,0 +1,66 @@
+/// One line in a group chat. Besides plain text, the app posts check-ins
+/// (progress logged on an objective), nudges and system notes into the same
+/// thread so the conversation and the work sit together.
+class GroupMessage {
+  String id;
+
+  String groupId;
+
+  String authorId;
+
+  String authorName;
+
+  String body;
+
+  /// "Text", "CheckIn", "Nudge" or "System".
+  String kind;
+
+  DateTime? sentAt;
+
+  /// True when the signed-in user wrote it.
+  bool mine;
+
+  GroupMessage({
+    this.id = "",
+    this.groupId = "",
+    this.authorId = "",
+    this.authorName = "",
+    this.body = "",
+    this.kind = "Text",
+    this.sentAt,
+    this.mine = false,
+  });
+
+  bool get isCheckIn => kind == "CheckIn";
+
+  bool get isNudge => kind == "Nudge";
+
+  bool get isSystem => kind == "System";
+
+  factory GroupMessage.fromJson(Map<String, dynamic> json) {
+    return GroupMessage(
+      id: json['id'] ?? "",
+      groupId: json['groupId'] ?? "",
+      authorId: json['authorId'] ?? "",
+      authorName: json['authorName'] ?? "",
+      body: json['body'] ?? "",
+      kind: json['kind'] ?? "Text",
+      sentAt:
+          json['sentAt'] == null ? null : DateTime.tryParse(json['sentAt']),
+      mine: json['mine'] ?? false,
+    );
+  }
+
+  Map<String, dynamic> toJson() {
+    final Map<String, dynamic> data = <String, dynamic>{};
+    data['id'] = id;
+    data['groupId'] = groupId;
+    data['authorId'] = authorId;
+    data['authorName'] = authorName;
+    data['body'] = body;
+    data['kind'] = kind;
+    data['sentAt'] = sentAt?.toIso8601String();
+    data['mine'] = mine;
+    return data;
+  }
+}
diff --git a/frontend/lib/Grounded/about/external/data/GroupObjective.dart b/frontend/lib/Grounded/about/external/data/GroupObjective.dart
new file mode 100644
index 0000000..a7ec7ff
--- /dev/null
+++ b/frontend/lib/Grounded/about/external/data/GroupObjective.dart
@@ -0,0 +1,58 @@
+/// One measurable part of a shared goal — "Run 100 km", "20 sessions" — that
+/// every member logs toward.
+class GroupObjective {
+  String id;
+
+  String title;
+
+  /// km, sessions, pages, hours…
+  String unit;
+
+  double target;
+
+  /// The group's total so far.
+  double current;
+
+  /// What the signed-in user has put in.
+  double mine;
+
+  GroupObjective({
+    this.id = "",
+    this.title = "",
+    this.unit = "",
+    this.target = 0,
+    this.current = 0,
+    this.mine = 0,
+  });
+
+  double get progress {
+    if (target <= 0) {
+      return 0;
+    }
+    return (current / target).clamp(0.0, 1.0);
+  }
+
+  bool get complete => target > 0 && current >= target;
+
+  factory GroupObjective.fromJson(Map<String, dynamic> json) {
+    return GroupObjective(
+      id: json['id'] ?? "",
+      title: json['title'] ?? "",
+      unit: json['unit'] ?? "",
+      target: (json['target'] ?? 0).toDouble(),
+      current: (json['current'] ?? 0).toDouble(),
+      mine: (json['mine'] ?? 0).toDouble(),
+    );
+  }
+
+  Map<String, dynamic> toJson() {
+    final Map<String, dynamic> data = <String, dynamic>{};
+    data['id'] = id;
+    data['title'] = title;
+    data['unit'] = unit;
+    data['target'] = target;
+    data['current'] = current;
+    data['mine'] = mine;
+    return data;
+  }
+}
diff --git a/frontend/lib/Grounded/about/external/initial/GroupGoalRequest.dart b/frontend/lib/Grounded/about/external/initial/GroupGoalRequest.dart
new file mode 100644
index 0000000..405cd8a
--- /dev/null
+++ b/frontend/lib/Grounded/about/external/initial/GroupGoalRequest.dart
@@ -0,0 +1,40 @@
+import 'ObjectiveDraft.dart';
+
+/// Creates a shared goal in a group, objectives and all.
+class GroupGoalRequest {
+  String groupId;
+
+  String? id;
+
+  String title;
+
+  String description;
+
+  String targetDate;
+
+  String colourHex;
+
+  List<ObjectiveDraft> objectives;
+
+  GroupGoalRequest({
+    this.groupId = "",
+    this.id,
+    this.title = "",
+    this.description = "",
+    this.targetDate = "",
+    this.colourHex = "",
+    List<ObjectiveDraft>? objectives,
+  }) : objectives = objectives ?? <ObjectiveDraft>[];
+
+  Map<String, dynamic> toJson() {
+    final Map<String, dynamic> data = <String, dynamic>{};
+    data['groupId'] = groupId;
+    data['id'] = id;
+    data['title'] = title;
+    data['description'] = description;
+    data['targetDate'] = targetDate;
+    data['colourHex'] = colourHex;
+    data['objectives'] = objectives.map((item) => item.toJson()).toList();
+    return data;
+  }
+}
diff --git a/frontend/lib/Grounded/about/external/initial/GroupMessageRequest.dart b/frontend/lib/Grounded/about/external/initial/GroupMessageRequest.dart
new file mode 100644
index 0000000..4d49926
--- /dev/null
+++ b/frontend/lib/Grounded/about/external/initial/GroupMessageRequest.dart
@@ -0,0 +1,18 @@
+/// Posts a message to a group chat.
+class GroupMessageRequest {
+  String groupId;
+
+  String body;
+
+  String kind;
+
+  GroupMessageRequest({this.groupId = "", this.body = "", this.kind = "Text"});
+
+  Map<String, dynamic> toJson() {
+    final Map<String, dynamic> data = <String, dynamic>{};
+    data['groupId'] = groupId;
+    data['body'] = body;
+    data['kind'] = kind;
+    return data;
+  }
+}
diff --git a/frontend/lib/Grounded/about/external/initial/GroupRequest.dart b/frontend/lib/Grounded/about/external/initial/GroupRequest.dart
new file mode 100644
index 0000000..66fd5db
--- /dev/null
+++ b/frontend/lib/Grounded/about/external/initial/GroupRequest.dart
@@ -0,0 +1,21 @@
+/// Creates a group, or renames one when [id] is set.
+class GroupRequest {
+  String? id;
+
+  String name;
+
+  String description;
+
+  String colourHex;
+
+  GroupRequest({this.id, this.name = "", this.description = "", this.colourHex = ""});
+
+  Map<String, dynamic> toJson() {
+    final Map<String, dynamic> data = <String, dynamic>{};
+    data['id'] = id;
+    data['name'] = name;
+    data['description'] = description;
+    data['colourHex'] = colourHex;
+    return data;
+  }
+}
diff --git a/frontend/lib/Grounded/about/external/initial/JoinGroupRequest.dart b/frontend/lib/Grounded/about/external/initial/JoinGroupRequest.dart
new file mode 100644
index 0000000..ba90c0c
--- /dev/null
+++ b/frontend/lib/Grounded/about/external/initial/JoinGroupRequest.dart
@@ -0,0 +1,12 @@
+/// Joins a group by the code a friend shared.
+class JoinGroupRequest {
+  String inviteCode;
+
+  JoinGroupRequest({this.inviteCode = ""});
+
+  Map<String, dynamic> toJson() {
+    final Map<String, dynamic> data = <String, dynamic>{};
+    data['inviteCode'] = inviteCode;
+    return data;
+  }
+}
diff --git a/frontend/lib/Grounded/about/external/initial/NudgeRequest.dart b/frontend/lib/Grounded/about/external/initial/NudgeRequest.dart
new file mode 100644
index 0000000..4bf9d83
--- /dev/null
+++ b/frontend/lib/Grounded/about/external/initial/NudgeRequest.dart
@@ -0,0 +1,15 @@
+/// Nudges one member, or everyone when [memberId] is empty.
+class NudgeRequest {
+  String groupId;
+
+  String memberId;
+
+  NudgeRequest({this.groupId = "", this.memberId = ""});
+
+  Map<String, dynamic> toJson() {
+    final Map<String, dynamic> data = <String, dynamic>{};
+    data['groupId'] = groupId;
+    data['memberId'] = memberId;
+    return data;
+  }
+}
diff --git a/frontend/lib/Grounded/about/external/initial/ObjectiveDraft.dart b/frontend/lib/Grounded/about/external/initial/ObjectiveDraft.dart
new file mode 100644
index 0000000..5b70dbd
--- /dev/null
+++ b/frontend/lib/Grounded/about/external/initial/ObjectiveDraft.dart
@@ -0,0 +1,18 @@
+/// One objective as typed into the shared-goal editor.
+class ObjectiveDraft {
+  String title;
+
+  String unit;
+
+  double target;
+
+  ObjectiveDraft({this.title = "", this.unit = "", this.target = 0});
+
+  Map<String, dynamic> toJson() {
+    final Map<String, dynamic> data = <String, dynamic>{};
+    data['title'] = title;
+    data['unit'] = unit;
+    data['target'] = target;
+    return data;
+  }
+}
diff --git a/frontend/lib/Grounded/about/external/initial/ObjectiveProgressRequest.dart b/frontend/lib/Grounded/about/external/initial/ObjectiveProgressRequest.dart
new file mode 100644
index 0000000..707372e
--- /dev/null
+++ b/frontend/lib/Grounded/about/external/initial/ObjectiveProgressRequest.dart
@@ -0,0 +1,24 @@
+/// Logs an amount against one objective of a shared goal.
+class ObjectiveProgressRequest {
+  String groupId;
+
+  String goalId;
+
+  String objectiveId;
+
+  double amount;
+
+  String note;
+
+  ObjectiveProgressRequest({this.groupId = "", this.goalId = "", this.objectiveId = "", this.amount = 0, this.note = ""});
+
+  Map<String, dynamic> toJson() {
+    final Map<String, dynamic> data = <String, dynamic>{};
+    data['groupId'] = groupId;
+    data['goalId'] = goalId;
+    data['objectiveId'] = objectiveId;
+    data['amount'] = amount;
+    data['note'] = note;
+    return data;
+  }
+}
diff --git a/frontend/lib/Grounded/comms/Comms.dart b/frontend/lib/Grounded/comms/Comms.dart
index 46b17e6..543741b 100644
--- a/frontend/lib/Grounded/comms/Comms.dart
+++ b/frontend/lib/Grounded/comms/Comms.dart
@@ -9,6 +9,12 @@ import '../about/external/initial/CompletionRequest.dart';
 import '../about/external/initial/DeferralRequest.dart';
 import '../about/external/initial/DeviceRequest.dart';
 import '../about/external/initial/GoalRequest.dart';
+import '../about/external/initial/GroupGoalRequest.dart';
+import '../about/external/initial/GroupMessageRequest.dart';
+import '../about/external/initial/GroupRequest.dart';
+import '../about/external/initial/JoinGroupRequest.dart';
+import '../about/external/initial/NudgeRequest.dart';
+import '../about/external/initial/ObjectiveProgressRequest.dart';
 import '../about/external/initial/IdRequest.dart';
 import '../about/external/initial/LoginData.dart';
 import '../about/external/initial/ReportCardRequest.dart';
@@ -512,4 +518,76 @@ class Comms implements ConnectComms {
     dio.options.headers = navigation.value;
     return await dio.post(navigation.key, data: request);
   }
+
+  // ── Groups ────────────────────────────────────────────────────────────────
+
+  @override
+  Future<Response> getMyGroups(HistoryRequest request) async {
+    Pair navigation = await getRequestHeaders(myGroups, "");
+    dio.options.headers = navigation.value;
+    return await dio.post(navigation.key, data: request);
+  }
+
+  @override
+  Future<Response> getGroupEntry(IdRequest request) async {
+    Pair navigation = await getRequestHeaders(oneGroup, "");
+    dio.options.headers = navigation.value;
+    return await dio.post(navigation.key, data: request);
+  }
+
+  @override
+  Future<Response> saveGroupEntry(GroupRequest request) async {
+    Pair navigation = await getRequestHeaders(saveGroup, "");
+    dio.options.headers = navigation.value;
+    return await dio.post(navigation.key, data: request);
+  }
+
+  @override
+  Future<Response> joinGroupEntry(JoinGroupRequest request) async {
+    Pair navigation = await getRequestHeaders(joinGroup, "");
+    dio.options.headers = navigation.value;
+    return await dio.post(navigation.key, data: request);
+  }
+
+  @override
+  Future<Response> leaveGroupEntry(IdRequest request) async {
+    Pair navigation = await getRequestHeaders(leaveGroup, "");
+    dio.options.headers = navigation.value;
+    return await dio.post(navigation.key, data: request);
+  }
+
+  @override
+  Future<Response> saveGroupGoalEntry(GroupGoalRequest request) async {
+    Pair navigation = await getRequestHeaders(saveGroupGoal, "");
+    dio.options.headers = navigation.value;
+    return await dio.post(navigation.key, data: request);
+  }
+
+  @override
+  Future<Response> logObjectiveProgress(ObjectiveProgressRequest request) async {
+    Pair navigation = await getRequestHeaders(logObjective, "");
+    dio.options.headers = navigation.value;
+    return await dio.post(navigation.key, data: request);
+  }
+
+  @override
+  Future<Response> getGroupMessages(IdRequest request) async {
+    Pair navigation = await getRequestHeaders(groupMessages, "");
+    dio.options.headers = navigation.value;
+    return await dio.post(navigation.key, data: request);
+  }
+
+  @override
+  Future<Response> sendGroupMessage(GroupMessageRequest request) async {
+    Pair navigation = await getRequestHeaders(sendGroupMessageTo, "");
+    dio.options.headers = navigation.value;
+    return await dio.post(navigation.key, data: request);
+  }
+
+  @override
+  Future<Response> nudgeGroupMember(NudgeRequest request) async {
+    Pair navigation = await getRequestHeaders(nudgeMember, "");
+    dio.options.headers = navigation.value;
+    return await dio.post(navigation.key, data: request);
+  }
 }
diff --git a/frontend/lib/Grounded/comms/CommsDirections.dart b/frontend/lib/Grounded/comms/CommsDirections.dart
index fd618c3..afdde49 100644
--- a/frontend/lib/Grounded/comms/CommsDirections.dart
+++ b/frontend/lib/Grounded/comms/CommsDirections.dart
@@ -172,3 +172,24 @@ String myPartners = 'Partner/Mine';
 String invitePartner = 'Partner/Invite';
 
 String partnerPolicy = 'Partner/Policy';
+
+// ── Groups ────────────────────────────────────────────────────────────────────
+String myGroups = 'Group/Mine';
+
+String oneGroup = 'Group/One';
+
+String saveGroup = 'Group/Save';
+
+String joinGroup = 'Group/Join';
+
+String leaveGroup = 'Group/Leave';
+
+String saveGroupGoal = 'Group/Goal/Save';
+
+String logObjective = 'Group/Objective/Log';
+
+String groupMessages = 'Group/Messages';
+
+String sendGroupMessageTo = 'Group/Message/Send';
+
+String nudgeMember = 'Group/Nudge';
diff --git a/frontend/lib/Grounded/comms/ConnectComms.dart b/frontend/lib/Grounded/comms/ConnectComms.dart
index 3621500..c3bba0d 100644
--- a/frontend/lib/Grounded/comms/ConnectComms.dart
+++ b/frontend/lib/Grounded/comms/ConnectComms.dart
@@ -9,6 +9,12 @@ import '../about/external/initial/CompletionRequest.dart';
 import '../about/external/initial/DeferralRequest.dart';
 import '../about/external/initial/DeviceRequest.dart';
 import '../about/external/initial/GoalRequest.dart';
+import '../about/external/initial/GroupGoalRequest.dart';
+import '../about/external/initial/GroupMessageRequest.dart';
+import '../about/external/initial/GroupRequest.dart';
+import '../about/external/initial/JoinGroupRequest.dart';
+import '../about/external/initial/NudgeRequest.dart';
+import '../about/external/initial/ObjectiveProgressRequest.dart';
 import '../about/external/initial/IdRequest.dart';
 import '../about/external/initial/LoginData.dart';
 import '../about/external/initial/ReportCardRequest.dart';
@@ -144,4 +150,25 @@ abstract class ConnectComms {
   Future<Response> getMyNotifications(HistoryRequest request);
 
   Future<Response> acknowledgeNudgeEntry(IdRequest request);
+
+  // ── Groups ──────────────────────────────────────────────────────────────
+  Future<Response> getMyGroups(HistoryRequest request);
+
+  Future<Response> getGroupEntry(IdRequest request);
+
+  Future<Response> saveGroupEntry(GroupRequest request);
+
+  Future<Response> joinGroupEntry(JoinGroupRequest request);
+
+  Future<Response> leaveGroupEntry(IdRequest request);
+
+  Future<Response> saveGroupGoalEntry(GroupGoalRequest request);
+
+  Future<Response> logObjectiveProgress(ObjectiveProgressRequest request);
+
+  Future<Response> getGroupMessages(IdRequest request);
+
+  Future<Response> sendGroupMessage(GroupMessageRequest request);
+
+  Future<Response> nudgeGroupMember(NudgeRequest request);
 }
diff --git a/frontend/lib/Grounded/designs/MemberAvatar.dart b/frontend/lib/Grounded/designs/MemberAvatar.dart
new file mode 100644
index 0000000..7ef9aa1
--- /dev/null
+++ b/frontend/lib/Grounded/designs/MemberAvatar.dart
@@ -0,0 +1,74 @@
+import 'package:flutter/material.dart';
+
+import '../about/internal/application/TextType.dart';
+import '../utils/Colors.dart';
+import '../utils/CommonUtils.dart';
+import 'scene/SceneArt.dart';
+import 'text/Text.dart';
+
+/// A member's square portrait: a landscape picked from their name with the
+/// initial on it, so everyone is recognisable without a photo.
+Widget memberAvatar(String name, double size, {Color? border}) {
+  const List<List<Color>> palettes = <List<Color>>[
+    sceneWorkout,
+    sceneMeditation,
+    sceneMustDo,
+  ];
+  final int seed = sceneSeed(name.isEmpty ? "?" : name);
+  final String initial =
+      name.isEmpty ? "?" : name.substring(0, 1).toUpperCase();
+
+  return Container(
+    width: size,
+    height: size,
+    decoration:
+        BoxDecoration(border: Border.all(color: border ?? colorWhite, width: 2)),
+    child: Stack(
+      fit: StackFit.expand,
+      children: [
+        SceneArt(palette: palettes[seed % palettes.length], seed: seed),
+        Center(
+          child: text(initial, size * 0.42, TextType.Medium, color: colorWhite),
+        ),
+      ],
+    ),
+  );
+}
+
+/// Several portraits overlapping, with "+N" once there are more than fit.
+Widget avatarStack(List<String> names, double size,
+    {int max = 4, Color? border}) {
+  final List<String> shown = names.take(max).toList();
+  final int extra = names.length - shown.length;
+  final double step = size * 0.68;
+  final int slots = shown.length + (extra > 0 ? 1 : 0);
+
+  return SizedBox(
+    width: slots == 0 ? 0 : size + step * (slots - 1),
+    height: size,
+    child: Stack(
+      children: [
+        for (int index = 0; index < shown.length; index++)
+          Positioned(
+            left: step * index,
+            child: memberAvatar(shown[index], size, border: border),
+          ),
+        if (extra > 0)
+          Positioned(
+            left: step * shown.length,
+            child: Container(
+              width: size,
+              height: size,
+              alignment: Alignment.center,
+              decoration: BoxDecoration(
+                color: colorNight,
+                border: Border.all(color: border ?? colorWhite, width: 2),
+              ),
+              child: text("+$extra", size * 0.34, TextType.Medium,
+                  color: colorWhite),
+            ),
+          ),
+      ],
+    ),
+  );
+}
diff --git a/frontend/lib/Grounded/informatics/AppDataManager.dart b/frontend/lib/Grounded/informatics/AppDataManager.dart
index 725f57d..5086bcd 100644
--- a/frontend/lib/Grounded/informatics/AppDataManager.dart
+++ b/frontend/lib/Grounded/informatics/AppDataManager.dart
@@ -14,6 +14,12 @@ import '../about/external/initial/CompletionRequest.dart';
 import '../about/external/initial/DeferralRequest.dart';
 import '../about/external/initial/DeviceRequest.dart';
 import '../about/external/initial/GoalRequest.dart';
+import '../about/external/initial/GroupGoalRequest.dart';
+import '../about/external/initial/GroupMessageRequest.dart';
+import '../about/external/initial/GroupRequest.dart';
+import '../about/external/initial/JoinGroupRequest.dart';
+import '../about/external/initial/NudgeRequest.dart';
+import '../about/external/initial/ObjectiveProgressRequest.dart';
 import '../about/external/initial/IdRequest.dart';
 import '../about/external/initial/LoginData.dart';
 import '../about/external/initial/ReportCardRequest.dart';
@@ -120,12 +126,6 @@ class AppDataManager implements DataManager {
   @override
   Future setAmnestySpent(int spent) => memory.setAmnestySpent(spent);
 
-  @override
-  Future<int> getWaterToday() => memory.getWaterToday();
-
-  @override
-  Future setWaterToday(int ml) => memory.setWaterToday(ml);
-
   @override
   Future<List<TodoItem>> getTodos() => memory.getTodos();
 
@@ -376,4 +376,36 @@ class AppDataManager implements DataManager {
   @override
   Future<Response> acknowledgeNudgeEntry(IdRequest request) =>
       comms.acknowledgeNudgeEntry(request);
+
+  // ── Groups ────────────────────────────────────────────────────────────────
+
+  @override
+  Future<Response> getMyGroups(HistoryRequest request) => comms.getMyGroups(request);
+
+  @override
+  Future<Response> getGroupEntry(IdRequest request) => comms.getGroupEntry(request);
+
+  @override
+  Future<Response> saveGroupEntry(GroupRequest request) => comms.saveGroupEntry(request);
+
+  @override
+  Future<Response> joinGroupEntry(JoinGroupRequest request) => comms.joinGroupEntry(request);
+
+  @override
+  Future<Response> leaveGroupEntry(IdRequest request) => comms.leaveGroupEntry(request);
+
+  @override
+  Future<Response> saveGroupGoalEntry(GroupGoalRequest request) => comms.saveGroupGoalEntry(request);
+
+  @override
+  Future<Response> logObjectiveProgress(ObjectiveProgressRequest request) => comms.logObjectiveProgress(request);
+
+  @override
+  Future<Response> getGroupMessages(IdRequest request) => comms.getGroupMessages(request);
+
+  @override
+  Future<Response> sendGroupMessage(GroupMessageRequest request) => comms.sendGroupMessage(request);
+
+  @override
+  Future<Response> nudgeGroupMember(NudgeRequest request) => comms.nudgeGroupMember(request);
 }
diff --git a/frontend/lib/Grounded/memory/ConnectInternalMemory.dart b/frontend/lib/Grounded/memory/ConnectInternalMemory.dart
index cbe3681..5b891fc 100644
--- a/frontend/lib/Grounded/memory/ConnectInternalMemory.dart
+++ b/frontend/lib/Grounded/memory/ConnectInternalMemory.dart
@@ -60,11 +60,6 @@ abstract class ConnectInternalMemory {
 
   Future setAmnestySpent(int spent);
 
-  /// Water drunk today in ml; a new day reads as 0.
-  Future<int> getWaterToday();
-
-  Future setWaterToday(int ml);
-
   /// The quick to-do list on Home.
   Future<List<TodoItem>> getTodos();
 
diff --git a/frontend/lib/Grounded/memory/InternalMemory.dart b/frontend/lib/Grounded/memory/InternalMemory.dart
index 236b673..38c45e1 100644
--- a/frontend/lib/Grounded/memory/InternalMemory.dart
+++ b/frontend/lib/Grounded/memory/InternalMemory.dart
@@ -41,8 +41,6 @@ class InternalMemory implements ConnectInternalMemory {
 
   static const String AMNESTY_SPENT = "AMNESTY_SPENT_Jr4xVh9KmT3gLc6B";
 
-  static const String WATER = "WATER_Qe7tNd4ZsM2kBv9C";
-
   static const String TODOS = "TODOS_Wm3kRb8TqZ5nHc2F";
 
   static const String SHOW_ONBOARDING = "SHOW_ONBOARDING_Nz6qGf2SdX7wPb4M";
@@ -257,31 +255,6 @@ class InternalMemory implements ConnectInternalMemory {
     await groundedStorage.write(key: AMNESTY_SPENT, value: spent.toString());
   }
 
-  String _today() {
-    final DateTime now = DateTime.now();
-    return "${now.year}-${now.month}-${now.day}";
-  }
-
-  @override
-  Future<int> getWaterToday() async {
-    String? value = await groundedStorage.read(key: WATER);
-
-    if (value != null) {
-      final Map<String, dynamic> entry = jsonDecode(value);
-      if (entry['day'] == _today()) {
-        return entry['ml'] ?? 0;
-      }
-    }
-
-    return 0;
-  }
-
-  @override
-  Future setWaterToday(int ml) async {
-    await groundedStorage.write(
-        key: WATER, value: jsonEncode({'day': _today(), 'ml': ml}));
-  }
-
   @override
   Future<List<TodoItem>> getTodos() async {
     String? value = await groundedStorage.read(key: TODOS);
diff --git a/frontend/lib/Grounded/mock/MockComms.dart b/frontend/lib/Grounded/mock/MockComms.dart
index a94319f..d13a84f 100644
--- a/frontend/lib/Grounded/mock/MockComms.dart
+++ b/frontend/lib/Grounded/mock/MockComms.dart
@@ -12,6 +12,12 @@ import '../about/external/initial/CompletionRequest.dart';
 import '../about/external/initial/DeferralRequest.dart';
 import '../about/external/initial/DeviceRequest.dart';
 import '../about/external/initial/GoalRequest.dart';
+import '../about/external/initial/GroupGoalRequest.dart';
+import '../about/external/initial/GroupMessageRequest.dart';
+import '../about/external/initial/GroupRequest.dart';
+import '../about/external/initial/JoinGroupRequest.dart';
+import '../about/external/initial/NudgeRequest.dart';
+import '../about/external/initial/ObjectiveProgressRequest.dart';
 import '../about/external/initial/IdRequest.dart';
 import '../about/external/initial/LoginData.dart';
 import '../about/external/initial/ReportCardRequest.dart';
@@ -19,6 +25,7 @@ import '../about/external/initial/SessionLogRequest.dart';
 import '../about/external/initial/SickModeRequest.dart';
 import '../about/external/initial/ToneRequest.dart';
 import '../comms/ConnectComms.dart';
+import 'MockGroups.dart';
 import 'MockStore.dart';
 
 /// A fake backend. Answers every call from [MockStore] after a short delay,
@@ -440,4 +447,36 @@ class MockComms implements ConnectComms {
 
   @override
   Future<Response> acknowledgeNudgeEntry(IdRequest request) => _done();
+
+  // ── Groups ────────────────────────────────────────────────────────────────
+
+  @override
+  Future<Response> getMyGroups(HistoryRequest request) => _ok(MockGroups.mine());
+
+  @override
+  Future<Response> getGroupEntry(IdRequest request) => _ok(MockGroups.one(request.id));
+
+  @override
+  Future<Response> saveGroupEntry(GroupRequest request) => _ok(MockGroups.save(request));
+
+  @override
+  Future<Response> joinGroupEntry(JoinGroupRequest request) => _ok(MockGroups.join(request));
+
+  @override
+  Future<Response> leaveGroupEntry(IdRequest request) => _ok(MockGroups.leave(request.id));
+
+  @override
+  Future<Response> saveGroupGoalEntry(GroupGoalRequest request) => _ok(MockGroups.saveGoal(request));
+
+  @override
+  Future<Response> logObjectiveProgress(ObjectiveProgressRequest request) => _ok(MockGroups.logProgress(request));
+
+  @override
+  Future<Response> getGroupMessages(IdRequest request) => _ok(MockGroups.messages(request.id));
+
+  @override
+  Future<Response> sendGroupMessage(GroupMessageRequest request) => _ok(MockGroups.send(request));
+
+  @override
+  Future<Response> nudgeGroupMember(NudgeRequest request) => _ok(MockGroups.nudge(request));
 }
diff --git a/frontend/lib/Grounded/mock/MockGroups.dart b/frontend/lib/Grounded/mock/MockGroups.dart
new file mode 100644
index 0000000..271b469
--- /dev/null
+++ b/frontend/lib/Grounded/mock/MockGroups.dart
@@ -0,0 +1,472 @@
+// MOCK DATA — TEMPORARY. See MockSwitch.dart.
+
+import 'dart:math';
+
+import '../about/external/initial/GroupGoalRequest.dart';
+import '../about/external/initial/GroupMessageRequest.dart';
+import '../about/external/initial/GroupRequest.dart';
+import '../about/external/initial/JoinGroupRequest.dart';
+import '../about/external/initial/NudgeRequest.dart';
+import '../about/external/initial/ObjectiveProgressRequest.dart';
+import '../utils/Colors.dart';
+import '../utils/CommonUtils.dart';
+import 'MockStore.dart';
+
+/// The fake backend's groups: a couple already joined, one waiting behind an
+/// invite code, and members who answer in the chat a moment after you post.
+class MockGroups {
+  static const String _me = "mock-user";
+
+  static const String _myName = "Alex";
+
+  static bool _seeded = false;
+
+  static final List<Map<String, dynamic>> _groups = <Map<String, dynamic>>[];
+
+  /// Groups that exist but you are not in yet, keyed by invite code.
+  static final Map<String, Map<String, dynamic>> _joinable =
+      <String, Map<String, dynamic>>{};
+
+  static final Map<String, List<Map<String, dynamic>>> _messages =
+      <String, List<Map<String, dynamic>>>{};
+
+  /// Replies that "arrive" once their time has passed.
+  static final List<Map<String, dynamic>> _pending = <Map<String, dynamic>>[];
+
+  static final Random _random = Random(7);
+
+  static Map<String, dynamic> _member(String id, String name,
+      {String role = "Member",
+      double kept = 0.7,
+      int streak = 2,
+      String standing = "Good",
+      int checkedInHoursAgo = 5}) {
+    return <String, dynamic>{
+      'id': id,
+      'name': name,
+      'role': role,
+      'keptRate': kept,
+      'streak': streak,
+      'standing': standing,
+      'lastCheckIn': DateTime.now()
+          .subtract(Duration(hours: checkedInHoursAgo))
+          .toIso8601String(),
+      'me': id == _me,
+    };
+  }
+
+  static Map<String, dynamic> _objective(
+      String id, String title, String unit, double target, double current,
+      double mine) {
+    return <String, dynamic>{
+      'id': id,
+      'title': title,
+      'unit': unit,
+      'target': target,
+      'current': current,
+      'mine': mine,
+    };
+  }
+
+  static Map<String, dynamic> _message(String groupId, String authorId,
+      String authorName, String body, int minutesAgo,
+      {String kind = "Text"}) {
+    return <String, dynamic>{
+      'id': MockStore.newId('msg'),
+      'groupId': groupId,
+      'authorId': authorId,
+      'authorName': authorName,
+      'body': body,
+      'kind': kind,
+      'sentAt': DateTime.now()
+          .subtract(Duration(minutes: minutesAgo))
+          .toIso8601String(),
+      'mine': authorId == _me,
+    };
+  }
+
+  static void _ensureSeeded() {
+    if (_seeded) {
+      return;
+    }
+    _seeded = true;
+
+    final DateTime now = DateTime.now();
+
+    _groups.addAll(<Map<String, dynamic>>[
+      <String, dynamic>{
+        'id': 'group-run',
+        'name': 'Morning Crew',
+        'description': 'Out the door before 7, five days a week.',
+        'colourHex': colorToHex(goalAccents[1]),
+        'inviteCode': 'MRN7AM',
+        'unread': 3,
+        'members': <Map<String, dynamic>>[
+          _member('m-sam', 'Sam',
+              role: 'Owner', kept: 0.92, streak: 11, checkedInHoursAgo: 2),
+          _member(_me, _myName, kept: 0.78, streak: 4, checkedInHoursAgo: 4),
+          _member('m-priya', 'Priya', kept: 0.85, streak: 7, checkedInHoursAgo: 3),
+          _member('m-jordan', 'Jordan',
+              kept: 0.41, streak: 0, standing: 'Warned', checkedInHoursAgo: 52),
+        ],
+        'goals': <Map<String, dynamic>>[
+          <String, dynamic>{
+            'id': 'gg-run',
+            'title': 'Run 200 km this month',
+            'description': 'Every kilometre counts, treadmill included.',
+            'targetDate': DateTime(now.year, now.month + 1, 0).toIso8601String(),
+            'colourHex': colorToHex(goalAccents[1]),
+            'objectives': <Map<String, dynamic>>[
+              _objective('ob-km', 'Distance run', 'km', 200, 86, 22),
+              _objective('ob-sessions', 'Runs logged', 'runs', 40, 17, 5),
+            ],
+          },
+          <String, dynamic>{
+            'id': 'gg-sleep',
+            'title': 'In bed before 23:00',
+            'description': 'Mornings start the night before.',
+            'targetDate': '',
+            'colourHex': colorToHex(goalAccents[4]),
+            'objectives': <Map<String, dynamic>>[
+              _objective('ob-nights', 'Early nights', 'nights', 60, 31, 9),
+            ],
+          },
+        ],
+      },
+      <String, dynamic>{
+        'id': 'group-thesis',
+        'name': 'Thesis Sprint',
+        'description': 'Drafts in by the 15th. No heroics, just pages.',
+        'colourHex': colorToHex(goalAccents[3]),
+        'inviteCode': 'THS15D',
+        'unread': 0,
+        'members': <Map<String, dynamic>>[
+          _member(_me, _myName,
+              role: 'Owner', kept: 0.78, streak: 4, checkedInHoursAgo: 4),
+          _member('m-mei', 'Mei', kept: 0.88, streak: 9, checkedInHoursAgo: 6),
+          _member('m-tom', 'Tom', kept: 0.63, streak: 1, checkedInHoursAgo: 20),
+        ],
+        'goals': <Map<String, dynamic>>[
+          <String, dynamic>{
+            'id': 'gg-drafts',
+            'title': 'Full drafts submitted',
+            'description': 'Three theses, one deadline.',
+            'targetDate': DateTime(now.year, now.month + 1, 15).toIso8601String(),
+            'colourHex': colorToHex(goalAccents[3]),
+            'objectives': <Map<String, dynamic>>[
+              _objective('ob-words', 'Words written', 'words', 30000, 18400, 7200),
+              _objective('ob-chapters', 'Chapters reviewed', 'chapters', 9, 3, 1),
+              _objective('ob-hours', 'Deep-work hours', 'hours', 120, 64, 23),
+            ],
+          },
+        ],
+      },
+    ]);
+
+    _joinable['WLK2GO'] = <String, dynamic>{
+      'id': 'group-walk',
+      'name': 'Weekend Walkers',
+      'description': 'Ten thousand steps, Saturday and Sunday, no excuses.',
+      'colourHex': colorToHex(goalAccents[5]),
+      'inviteCode': 'WLK2GO',
+      'unread': 1,
+      'members': <Map<String, dynamic>>[
+        _member('m-ade', 'Ade', role: 'Owner', kept: 0.81, streak: 6),
+        _member('m-lena', 'Lena', kept: 0.74, streak: 3),
+      ],
+      'goals': <Map<String, dynamic>>[
+        <String, dynamic>{
+          'id': 'gg-steps',
+          'title': '1 million steps together',
+          'description': '',
+          'targetDate': '',
+          'colourHex': colorToHex(goalAccents[5]),
+          'objectives': <Map<String, dynamic>>[
+            _objective('ob-steps', 'Steps', 'steps', 1000000, 412000, 0),
+          ],
+        },
+      ],
+    };
+
+    _messages['group-run'] = <Map<String, dynamic>>[
+      _message('group-run', 'm-sam', 'Sam',
+          'Same route tomorrow? Gate at 6:15.', 60 * 20),
+      _message('group-run', _me, _myName, "I'm in. Bringing Priya's spare torch.",
+          60 * 19 + 40),
+      _message('group-run', 'm-priya', 'Priya', 'logged 6 km on Distance run',
+          60 * 3, kind: 'CheckIn'),
+      _message('group-run', 'm-sam', 'Sam', 'logged 8 km on Distance run',
+          60 * 2, kind: 'CheckIn'),
+      _message('group-run', 'm-sam', 'Sam',
+          'nudged Jordan: two days without a run, we miss you out there',
+          95, kind: 'Nudge'),
+      _message('group-run', 'm-priya', 'Priya',
+          '86 km down. We need about 9 a day to make it, doable.', 40),
+    ];
+    _messages['group-thesis'] = <Map<String, dynamic>>[
+      _message('group-thesis', _me, _myName, 'started the group', 60 * 24 * 6,
+          kind: 'System'),
+      _message('group-thesis', 'm-mei', 'Mei',
+          'Chapter 3 is with my supervisor. Terrified.', 60 * 26),
+      _message('group-thesis', _me, _myName, 'logged 1,200 words on Words written',
+          60 * 22, kind: 'CheckIn'),
+      _message('group-thesis', 'm-tom', 'Tom',
+          'Library 9 to 1 tomorrow if anyone wants a co-working block.', 60 * 7),
+    ];
+    _messages['group-walk'] = <Map<String, dynamic>>[
+      _message('group-walk', 'm-ade', 'Ade',
+          'Welcome! Saturday loop starts at the bridge, 9:00.', 60 * 30),
+    ];
+  }
+
+  static Map<String, dynamic>? _find(String id) {
+    for (Map<String, dynamic> group in _groups) {
+      if (group['id'] == id) {
+        return group;
+      }
+    }
+    return null;
+  }
+
+  /// Moves any replies whose moment has come into their threads.
+  static void _deliver() {
+    final DateTime now = DateTime.now();
+    final List<Map<String, dynamic>> due = _pending
+        .where((item) => DateTime.parse(item['sentAt']).isBefore(now))
+        .toList();
+    for (Map<String, dynamic> message in due) {
+      _pending.remove(message);
+      _messages.putIfAbsent(message['groupId'], () => <Map<String, dynamic>>[])
+          .add(message);
+      final Map<String, dynamic>? group = _find(message['groupId']);
+      if (group != null) {
+        group['unread'] = (group['unread'] ?? 0) + 1;
+      }
+    }
+  }
+
+  static Map<String, dynamic> _withLast(Map<String, dynamic> group) {
+    final List<Map<String, dynamic>> thread =
+        _messages[group['id']] ?? <Map<String, dynamic>>[];
+    final Map<String, dynamic> copy = Map<String, dynamic>.from(group);
+    if (thread.isNotEmpty) {
+      final Map<String, dynamic> last = thread.last;
+      copy['lastMessage'] = last['body'];
+      copy['lastAuthor'] = last['authorName'];
+      copy['lastMessageAt'] = last['sentAt'];
+    }
+    return copy;
+  }
+
+  static void _post(String groupId, String body, String kind) {
+    _messages.putIfAbsent(groupId, () => <Map<String, dynamic>>[]).add(
+        _message(groupId, _me, _myName, body, 0, kind: kind));
+  }
+
+  /// Someone answers a few seconds later, so the chat feels inhabited.
+  static void _queueReply(String groupId) {
+    final Map<String, dynamic>? group = _find(groupId);
+    if (group == null) {
+      return;
+    }
+    final List<dynamic> others = (group['members'] as List)
+        .where((member) => member['id'] != _me)
+        .toList();
+    if (others.isEmpty) {
+      return;
+    }
+    const List<String> lines = <String>[
+      "Love it. Keep that going.",
+      "Same here, just finished mine.",
+      "That's the spirit.",
+      "Noted. I'll match you tomorrow.",
+      "Good — that puts us back on pace.",
+      "Who's in for the next one?",
+    ];
+    final Map<String, dynamic> author = others[_random.nextInt(others.length)];
+    final Map<String, dynamic> reply = _message(groupId, author['id'],
+        author['name'], lines[_random.nextInt(lines.length)], 0);
+    reply['sentAt'] =
+        DateTime.now().add(const Duration(seconds: 3)).toIso8601String();
+    _pending.add(reply);
+  }
+
+  static String _code() {
+    const String letters = "ABCDEFGHJKLMNPQRSTUVWXYZ23456789";
+    return List<String>.generate(
+        6, (index) => letters[_random.nextInt(letters.length)]).join();
+  }
+
+  // ── Endpoints ─────────────────────────────────────────────────────────────
+
+  static List<Map<String, dynamic>> mine() {
+    _ensureSeeded();
+    _deliver();
+    return _groups.map(_withLast).toList();
+  }
+
+  static Map<String, dynamic> one(String id) {
+    _ensureSeeded();
+    _deliver();
+    return _withLast(_find(id) ?? <String, dynamic>{});
+  }
+
+  static Map<String, dynamic> save(GroupRequest request) {
+    _ensureSeeded();
+    final Map<String, dynamic>? existing =
+        request.id == null ? null : _find(request.id!);
+    if (existing != null) {
+      existing['name'] = request.name;
+      existing['description'] = request.description;
+      existing['colourHex'] = request.colourHex;
+      return _withLast(existing);
+    }
+
+    final String id = MockStore.newId('group');
+    final Map<String, dynamic> group = <String, dynamic>{
+      'id': id,
+      'name': request.name,
+      'description': request.description,
+      'colourHex': request.colourHex,
+      'inviteCode': _code(),
+      'unread': 0,
+      'members': <Map<String, dynamic>>[
+        _member(_me, _myName, role: 'Owner', kept: 0.78, streak: 4,
+            checkedInHoursAgo: 0),
+      ],
+      'goals': <Map<String, dynamic>>[],
+    };
+    _groups.insert(0, group);
+    _post(id, 'started the group', 'System');
+    return _withLast(group);
+  }
+
+  static Map<String, dynamic> join(JoinGroupRequest request) {
+    _ensureSeeded();
+    final String code = request.inviteCode.trim().toUpperCase();
+
+    for (Map<String, dynamic> group in _groups) {
+      if (group['inviteCode'] == code) {
+        return _withLast(group);
+      }
+    }
+
+    // Any well-formed code finds the waiting group, so the preview always
+    // has something to join.
+    final Map<String, dynamic> group = _joinable.remove(code) ??
+        (_joinable.isNotEmpty
+            ? _joinable.remove(_joinable.keys.first)!
+            : <String, dynamic>{
+                'id': MockStore.newId('group'),
+                'name': 'Group $code',
+                'description': '',
+                'colourHex': colorToHex(goalAccents[0]),
+                'inviteCode': code,
+                'unread': 0,
+                'members': <Map<String, dynamic>>[],
+                'goals': <Map<String, dynamic>>[],
+              });
+    (group['members'] as List).add(_member(_me, _myName,
+        kept: 0.78, streak: 4, checkedInHoursAgo: 0));
+    _groups.insert(0, group);
+    _post(group['id'], 'joined the group', 'System');
+    _queueReply(group['id']);
+    return _withLast(group);
+  }
+
+  static Map<String, dynamic> leave(String id) {
+    _ensureSeeded();
+    _groups.removeWhere((group) => group['id'] == id);
+    return <String, dynamic>{'success': true};
+  }
+
+  static Map<String, dynamic> saveGoal(GroupGoalRequest request) {
+    _ensureSeeded();
+    final Map<String, dynamic>? group = _find(request.groupId);
+    if (group == null) {
+      return <String, dynamic>{};
+    }
+    final Map<String, dynamic> goal = <String, dynamic>{
+      'id': MockStore.newId('gg'),
+      'title': request.title,
+      'description': request.description,
+      'targetDate': request.targetDate,
+      'colourHex': request.colourHex,
+      'objectives': request.objectives
+          .map((draft) => _objective(MockStore.newId('ob'), draft.title,
+              draft.unit, draft.target, 0, 0))
+          .toList(),
+    };
+    (group['goals'] as List).add(goal);
+    _post(group['id'], 'added a shared goal: ${request.title}', 'System');
+    return _withLast(group);
+  }
+
+  static Map<String, dynamic> logProgress(ObjectiveProgressRequest request) {
+    _ensureSeeded();
+    final Map<String, dynamic>? group = _find(request.groupId);
+    if (group == null) {
+      return <String, dynamic>{};
+    }
+    for (Map<String, dynamic> goal in (group['goals'] as List)) {
+      if (goal['id'] != request.goalId) {
+        continue;
+      }
+      for (Map<String, dynamic> objective in (goal['objectives'] as List)) {
+        if (objective['id'] != request.objectiveId) {
+          continue;
+        }
+        objective['current'] = (objective['current'] as num) + request.amount;
+        objective['mine'] = (objective['mine'] as num) + request.amount;
+        final String amount = formatAmount(request.amount);
+        _post(
+            group['id'],
+            'logged $amount ${objective['unit']} on ${objective['title']}'
+            '${request.note.isEmpty ? "" : " — ${request.note}"}',
+            'CheckIn');
+        _queueReply(group['id']);
+      }
+    }
+    for (Map<String, dynamic> member in (group['members'] as List)) {
+      if (member['id'] == _me) {
+        member['lastCheckIn'] = DateTime.now().toIso8601String();
+      }
+    }
+    return _withLast(group);
+  }
+
+  static List<Map<String, dynamic>> messages(String groupId) {
+    _ensureSeeded();
+    _deliver();
+    final Map<String, dynamic>? group = _find(groupId);
+    if (group != null) {
+      group['unread'] = 0;
+    }
+    return List<Map<String, dynamic>>.from(
+        _messages[groupId] ?? <Map<String, dynamic>>[]);
+  }
+
+  static Map<String, dynamic> send(GroupMessageRequest request) {
+    _ensureSeeded();
+    _post(request.groupId, request.body, request.kind);
+    _queueReply(request.groupId);
+    return _messages[request.groupId]!.last;
+  }
+
+  static Map<String, dynamic> nudge(NudgeRequest request) {
+    _ensureSeeded();
+    final Map<String, dynamic>? group = _find(request.groupId);
+    if (group == null) {
+      return <String, dynamic>{'success': false};
+    }
+    String who = "everyone";
+    for (Map<String, dynamic> member in (group['members'] as List)) {
+      if (member['id'] == request.memberId) {
+        who = member['name'];
+      }
+    }
+    _post(request.groupId, 'nudged $who: today still counts, go get it',
+        'Nudge');
+    return <String, dynamic>{'success': true};
+  }
+}
diff --git a/frontend/lib/Grounded/mock/MockMemory.dart b/frontend/lib/Grounded/mock/MockMemory.dart
index ed46f7c..f7050d2 100644
--- a/frontend/lib/Grounded/mock/MockMemory.dart
+++ b/frontend/lib/Grounded/mock/MockMemory.dart
@@ -19,9 +19,8 @@ class MockMemory extends InternalMemory {
       setMyDescription(
           MeDescription(id: "mock-user", name: "Alex", token: "mock-token"));
       setUserDetails(UserDetails(pic: "", name: "Alex"));
-      setWaterToday(1250);
       setTodos(<TodoItem>[
-        TodoItem(id: "t1", title: "Refill water bottle"),
+        TodoItem(id: "t1", title: "Pick up gym kit"),
         TodoItem(id: "t2", title: "Book physio for Thursday"),
         TodoItem(id: "t3", title: "Reply to Sam about Saturday", done: true),
       ]);
diff --git a/frontend/lib/Grounded/see/group/ConnectGroupChat.dart b/frontend/lib/Grounded/see/group/ConnectGroupChat.dart
new file mode 100644
index 0000000..f554862
--- /dev/null
+++ b/frontend/lib/Grounded/see/group/ConnectGroupChat.dart
@@ -0,0 +1,10 @@
+import '../../about/external/data/GroupMessage.dart';
+
+abstract class ConnectGroupChat {
+  void onMessagesLoaded(List<GroupMessage> messages);
+
+  void onMessageSent(GroupMessage message);
+
+  /// The send failed; the text goes back in the box so nothing is lost.
+  void onSendFailed(String body);
+}
diff --git a/frontend/lib/Grounded/see/group/ConnectGroupDetail.dart b/frontend/lib/Grounded/see/group/ConnectGroupDetail.dart
new file mode 100644
index 0000000..8b8fccf
--- /dev/null
+++ b/frontend/lib/Grounded/see/group/ConnectGroupDetail.dart
@@ -0,0 +1,12 @@
+import '../../about/external/data/Group.dart';
+
+abstract class ConnectGroupDetail {
+  void onGroupLoaded(Group group);
+
+  /// Progress landed; the group comes back with the new totals.
+  void onProgressLogged(Group group, String summary);
+
+  void onNudged(String who);
+
+  void onLeft();
+}
diff --git a/frontend/lib/Grounded/see/group/ConnectGroupEditor.dart b/frontend/lib/Grounded/see/group/ConnectGroupEditor.dart
new file mode 100644
index 0000000..820d460
--- /dev/null
+++ b/frontend/lib/Grounded/see/group/ConnectGroupEditor.dart
@@ -0,0 +1,6 @@
+import '../../about/external/data/Group.dart';
+
+abstract class ConnectGroupEditor {
+  /// Created or joined — either way you are now in it.
+  void onGroupReady(Group group);
+}
diff --git a/frontend/lib/Grounded/see/group/ConnectGroupGoalEditor.dart b/frontend/lib/Grounded/see/group/ConnectGroupGoalEditor.dart
new file mode 100644
index 0000000..840f4a1
--- /dev/null
+++ b/frontend/lib/Grounded/see/group/ConnectGroupGoalEditor.dart
@@ -0,0 +1,3 @@
+abstract class ConnectGroupGoalEditor {
+  void onGoalSaved();
+}
diff --git a/frontend/lib/Grounded/see/group/ConnectGroups.dart b/frontend/lib/Grounded/see/group/ConnectGroups.dart
new file mode 100644
index 0000000..cbb43b8
--- /dev/null
+++ b/frontend/lib/Grounded/see/group/ConnectGroups.dart
@@ -0,0 +1,5 @@
+import '../../about/external/data/Group.dart';
+
+abstract class ConnectGroups {
+  void onGroupsLoaded(List<Group> groups);
+}
diff --git a/frontend/lib/Grounded/see/group/GroupChat.dart b/frontend/lib/Grounded/see/group/GroupChat.dart
new file mode 100644
index 0000000..257b3cd
--- /dev/null
+++ b/frontend/lib/Grounded/see/group/GroupChat.dart
@@ -0,0 +1,13 @@
+import 'package:flutter/material.dart';
+
+import '../../about/external/data/Group.dart';
+import 'GroupChatState.dart';
+
+class GroupChat extends StatefulWidget {
+  final Group group;
+
+  const GroupChat({super.key, required this.group});
+
+  @override
+  State<GroupChat> createState() => GroupChatState();
+}
diff --git a/frontend/lib/Grounded/see/group/GroupChatState.dart b/frontend/lib/Grounded/see/group/GroupChatState.dart
new file mode 100644
index 0000000..ddcdd98
--- /dev/null
+++ b/frontend/lib/Grounded/see/group/GroupChatState.dart
@@ -0,0 +1,464 @@
+import 'dart:async';
+
+import 'package:flutter/cupertino.dart';
+import 'package:flutter/material.dart';
+import 'package:stacked/stacked.dart';
+
+import '../../about/external/data/GroupMessage.dart';
+import '../../about/external/initial/GroupMessageRequest.dart';
+import '../../about/internal/application/TextType.dart';
+import '../../designs/AmbientBackground.dart';
+import '../../designs/GlassSurface.dart';
+import '../../designs/MemberAvatar.dart';
+import '../../designs/Responsive.dart';
+import '../../designs/input/InputFields.dart';
+import '../../designs/text/Text.dart';
+import '../../utils/Colors.dart';
+import '../../utils/CommonUtils.dart';
+import 'ConnectGroupChat.dart';
+import 'GroupChat.dart';
+import 'ViewGroupChat.dart';
+
+class GroupChatState extends State<GroupChat> implements ConnectGroupChat {
+  ViewGroupChat? _model;
+
+  List<GroupMessage> _messages = <GroupMessage>[];
+
+  final TextEditingController _input = TextEditingController();
+
+  Timer? _poll;
+
+  /// How often the open chat looks for new messages.
+  static const Duration _pollEvery = Duration(seconds: 4);
+
+  static const List<String> _quickReplies = <String>[
+    "Done for today",
+    "On my way",
+    "Need a push",
+    "Who's in tomorrow?",
+  ];
+
+  @override
+  void dispose() {
+    _poll?.cancel();
+    _input.dispose();
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return ViewModelBuilder<ViewGroupChat>.reactive(
+      viewModelBuilder: () => ViewGroupChat(context, this),
+      onViewModelReady: (viewModel) {
+        _model = viewModel;
+        _initiate();
+      },
+      builder: (context, viewModel, child) => LayoutBuilder(
+        builder: (BuildContext context, BoxConstraints constraints) {
+          return Responsive(
+            mobile: _mobileView(constraints),
+            tablet: _mobileView(constraints),
+            desktop: _mobileView(constraints),
+          );
+        },
+      ),
+    );
+  }
+
+  void _initiate() {
+    _model?.loadMessages(widget.group.id);
+    _poll = Timer.periodic(_pollEvery, _onPoll);
+  }
+
+  // ── Handlers ──────────────────────────────────────────────────────────────
+
+  void _onBack() {
+    Navigator.pop(context, true);
+  }
+
+  void _onPoll(Timer timer) {
+    _model?.refresh(widget.group.id);
+  }
+
+  void _onSend(String value) {
+    final String body = value.trim();
+    if (body.isEmpty) {
+      return;
+    }
+
+    _input.clear();
+    _model?.send(GroupMessageRequest(groupId: widget.group.id, body: body));
+  }
+
+  void _onSendPressed() {
+    _onSend(_input.text);
+  }
+
+  void _onQuickReply(String reply) {
+    _onSend(reply);
+  }
+
+  // ── Views ─────────────────────────────────────────────────────────────────
+
+  Widget _mobileView(BoxConstraints constraints) {
+    final List<GroupMessage> newestFirst = _messages.reversed.toList();
+
+    return Scaffold(
+      backgroundColor: colorAmbientMid,
+      body: AmbientBackground(
+        child: Column(
+          children: [
+            _topBar(),
+            Expanded(
+              child: ListView.builder(
+                reverse: true,
+                padding: const EdgeInsets.fromLTRB(16, 12, 16, 12),
+                itemCount: newestFirst.length,
+                itemBuilder: (context, index) {
+                  final GroupMessage message = newestFirst[index];
+                  final GroupMessage? older = index + 1 < newestFirst.length
+                      ? newestFirst[index + 1]
+                      : null;
+                  final bool newDay = older == null ||
+                      !_sameDay(older.sentAt, message.sentAt);
+
+                  return Column(
+                    crossAxisAlignment: CrossAxisAlignment.stretch,
+                    mainAxisSize: MainAxisSize.min,
+                    children: [
+                      if (newDay) _dayLabel(message.sentAt),
+                      _message(message, older),
+                    ],
+                  );
+                },
+              ),
+            ),
+            _composer(),
+          ],
+        ),
+      ),
+    );
+  }
+
+  Widget _topBar() {
+    final Color accent = goalColor(widget.group.colourHex);
+
+    return Container(
+      decoration: BoxDecoration(
+        gradient: LinearGradient(
+          begin: Alignment.topLeft,
+          end: Alignment.bottomRight,
+          colors: <Color>[
+            Color.lerp(accent, colorHeaderBottom, 0.55)!,
+            colorHeaderBottom,
+          ],
+        ),
+      ),
+      padding: EdgeInsets.fromLTRB(
+          16, MediaQuery.of(context).padding.top + 10, 16, 14),
+      child: Row(
+        children: [
+          glassCircle(CupertinoIcons.arrow_left, _onBack,
+              size: 46, onDark: true),
+          const SizedBox(width: 14),
+          Expanded(
+            child: Column(
+              crossAxisAlignment: CrossAxisAlignment.start,
+              mainAxisSize: MainAxisSize.min,
+              children: [
+                text(widget.group.name, 19, TextType.Medium,
+                    color: colorWhite,
+                    maxLines: 1,
+                    overflow: TextOverflow.ellipsis),
+                const SizedBox(height: 3),
+                text(
+                    widget.group.members
+                        .map((member) => member.me ? "you" : member.name)
+                        .join(", "),
+                    12,
+                    TextType.Regular,
+                    color: colorHeaderMuted,
+                    maxLines: 1,
+                    overflow: TextOverflow.ellipsis),
+              ],
+            ),
+          ),
+          const SizedBox(width: 10),
+          avatarStack(
+              widget.group.members.map((member) => member.name).toList(), 30,
+              max: 3, border: colorHeaderBottom),
+        ],
+      ),
+    );
+  }
+
+  Widget _dayLabel(DateTime? moment) {
+    return Padding(
+      padding: const EdgeInsets.symmetric(vertical: 14),
+      child: Center(
+        child: Container(
+          padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 5),
+          color: colorWhite.withValues(alpha: 0.7),
+          child: text(_dayName(moment), 11, TextType.Medium,
+              color: colorInkSoft),
+        ),
+      ),
+    );
+  }
+
+  /// Text as bubbles, check-ins and nudges as cards in the thread, system
+  /// notes as a quiet centred line.
+  Widget _message(GroupMessage message, GroupMessage? older) {
+    if (message.isSystem) {
+      return Padding(
+        padding: const EdgeInsets.symmetric(vertical: 8),
+        child: text(
+          "${message.mine ? "You" : message.authorName} ${message.body}",
+          12,
+          TextType.Regular,
+          color: colorInkSoft,
+          align: TextAlign.center,
+        ),
+      );
+    }
+
+    if (message.isCheckIn || message.isNudge) {
+      return _eventCard(message);
+    }
+
+    // Consecutive lines from one person share a single name and portrait.
+    final bool grouped = older != null &&
+        older.authorId == message.authorId &&
+        !older.isSystem &&
+        !older.isCheckIn &&
+        !older.isNudge &&
+        _sameDay(older.sentAt, message.sentAt);
+
+    if (message.mine) {
+      return Padding(
+        padding: EdgeInsets.only(top: grouped ? 4 : 12, left: 64),
+        child: Align(
+          alignment: Alignment.centerRight,
+          child: Container(
+            padding: const EdgeInsets.fromLTRB(14, 11, 14, 10),
+            color: colorNight,
+            child: Column(
+              crossAxisAlignment: CrossAxisAlignment.end,
+              mainAxisSize: MainAxisSize.min,
+              children: [
+                text(message.body, 15, TextType.Regular,
+                    color: colorWhite, height: 1.4),
+                const SizedBox(height: 4),
+                text(_time(message.sentAt), 10, TextType.Regular,
+                    color: colorHeaderMuted),
+              ],
+            ),
+          ),
+        ),
+      );
+    }
+
+    final Color tone = _authorColour(message.authorName);
+
+    return Padding(
+      padding: EdgeInsets.only(top: grouped ? 4 : 12, right: 56),
+      child: Row(
+        crossAxisAlignment: CrossAxisAlignment.end,
+        children: [
+          grouped
+              ? const SizedBox(width: 34)
+              : memberAvatar(message.authorName, 34),
+          const SizedBox(width: 8),
+          Flexible(
+            child: Container(
+              padding: const EdgeInsets.fromLTRB(14, 10, 14, 10),
+              decoration: BoxDecoration(
+                color: colorWhite,
+                border: Border.all(color: colorGlassBorder),
+              ),
+              child: Column(
+                crossAxisAlignment: CrossAxisAlignment.start,
+                mainAxisSize: MainAxisSize.min,
+                children: [
+                  if (!grouped) ...[
+                    text(message.authorName, 12, TextType.Medium, color: tone),
+                    const SizedBox(height: 3),
+                  ],
+                  text(message.body, 15, TextType.Regular,
+                      color: colorInk, height: 1.4),
+                  const SizedBox(height: 4),
+                  text(_time(message.sentAt), 10, TextType.Regular,
+                      color: colorInkSoft),
+                ],
+              ),
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+
+  /// A check-in or a nudge, set apart from the talk so the work is visible.
+  Widget _eventCard(GroupMessage message) {
+    final bool checkIn = message.isCheckIn;
+    final String who = message.mine ? "You" : message.authorName;
+
+    return Padding(
+      padding: const EdgeInsets.only(top: 12),
+      child: Container(
+        padding: const EdgeInsets.fromLTRB(12, 12, 14, 12),
+        decoration: BoxDecoration(
+          color: checkIn ? colorStandingGoodBg : colorOverdueWarmEnd,
+          border: Border(
+            left: BorderSide(
+              color: checkIn ? colorPositive : colorBarStandard,
+              width: 4,
+            ),
+          ),
+        ),
+        child: Row(
+          children: [
+            memberAvatar(message.authorName, 34),
+            const SizedBox(width: 12),
+            Expanded(
+              child: Column(
+                crossAxisAlignment: CrossAxisAlignment.start,
+                mainAxisSize: MainAxisSize.min,
+                children: [
+                  Row(
+                    children: [
+                      Icon(
+                        checkIn
+                            ? CupertinoIcons.checkmark_seal_fill
+                            : CupertinoIcons.hand_point_right_fill,
+                        size: 13,
+                        color: checkIn ? colorPositive : colorWarning,
+                      ),
+                      const SizedBox(width: 5),
+                      text(checkIn ? "CHECK-IN" : "NUDGE", 10, TextType.Bold,
+                          color: checkIn ? colorPositive : colorWarning,
+                          letterSpacing: 1.0),
+                      const Spacer(),
+                      text(_time(message.sentAt), 10, TextType.Regular,
+                          color: colorInkSoft),
+                    ],
+                  ),
+                  const SizedBox(height: 4),
+                  text("$who ${message.body}", 14, TextType.Regular,
+                      color: colorInk, height: 1.4),
+                ],
+              ),
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+
+  Widget _composer() {
+    return Container(
+      color: colorWhite,
+      padding: EdgeInsets.fromLTRB(
+          0, 10, 0, MediaQuery.of(context).padding.bottom + 10),
+      child: Column(
+        mainAxisSize: MainAxisSize.min,
+        children: [
+          SizedBox(
+            height: 38,
+            child: ListView.separated(
+              scrollDirection: Axis.horizontal,
+              padding: const EdgeInsets.symmetric(horizontal: 16),
+              itemCount: _quickReplies.length,
+              separatorBuilder: (context, index) => const SizedBox(width: 8),
+              itemBuilder: (context, index) => GestureDetector(
+                onTap: () => _onQuickReply(_quickReplies[index]),
+                child: Container(
+                  padding: const EdgeInsets.symmetric(horizontal: 14),
+                  alignment: Alignment.center,
+                  color: colorAmbientMid,
+                  child: text(_quickReplies[index], 13, TextType.Regular,
+                      color: colorInk),
+                ),
+              ),
+            ),
+          ),
+          const SizedBox(height: 8),
+          Padding(
+            padding: const EdgeInsets.fromLTRB(16, 0, 10, 0),
+            child: Row(
+              children: [
+                Expanded(
+                  child: quickAddField(_input, "Message the group", _onSend),
+                ),
+                const SizedBox(width: 8),
+                GestureDetector(
+                  onTap: _onSendPressed,
+                  child: Container(
+                    width: 50,
+                    height: 50,
+                    color: colorNight,
+                    child: Icon(CupertinoIcons.paperplane_fill,
+                        size: 20, color: colorLime),
+                  ),
+                ),
+              ],
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+
+  // ── Helpers ───────────────────────────────────────────────────────────────
+
+  Color _authorColour(String name) {
+    return goalAccents[sceneSeed(name) % goalAccents.length];
+  }
+
+  bool _sameDay(DateTime? a, DateTime? b) {
+    if (a == null || b == null) return false;
+    final DateTime x = a.toLocal();
+    final DateTime y = b.toLocal();
+    return x.year == y.year && x.month == y.month && x.day == y.day;
+  }
+
+  String _dayName(DateTime? moment) {
+    if (moment == null) return "";
+    final DateTime now = DateTime.now();
+    if (_sameDay(moment, now)) return "Today";
+    if (_sameDay(moment, now.subtract(const Duration(days: 1)))) {
+      return "Yesterday";
+    }
+    return formatDate(moment.toLocal());
+  }
+
+  String _time(DateTime? moment) {
+    if (moment == null) return "";
+    final DateTime local = moment.toLocal();
+    return "${local.hour.toString().padLeft(2, "0")}:${local.minute.toString().padLeft(2, "0")}";
+  }
+
+  // ── ConnectGroupChat ──────────────────────────────────────────────────────
+
+  @override
+  void onMessagesLoaded(List<GroupMessage> messages) {
+    if (!mounted) return;
+    setState(() {
+      _messages = messages;
+    });
+  }
+
+  @override
+  void onMessageSent(GroupMessage message) {
+    if (!mounted) return;
+    setState(() {
+      _messages = <GroupMessage>[..._messages, message];
+    });
+  }
+
+  @override
+  void onSendFailed(String body) {
+    if (!mounted) return;
+    _input.text = body;
+  }
+}
diff --git a/frontend/lib/Grounded/see/group/GroupDetail.dart b/frontend/lib/Grounded/see/group/GroupDetail.dart
new file mode 100644
index 0000000..830a29f
--- /dev/null
+++ b/frontend/lib/Grounded/see/group/GroupDetail.dart
@@ -0,0 +1,13 @@
+import 'package:flutter/material.dart';
+
+import '../../about/external/data/Group.dart';
+import 'GroupDetailState.dart';
+
+class GroupDetail extends StatefulWidget {
+  final Group group;
+
+  const GroupDetail({super.key, required this.group});
+
+  @override
+  State<GroupDetail> createState() => GroupDetailState();
+}
diff --git a/frontend/lib/Grounded/see/group/GroupDetailState.dart b/frontend/lib/Grounded/see/group/GroupDetailState.dart
new file mode 100644
index 0000000..d3f702e
--- /dev/null
+++ b/frontend/lib/Grounded/see/group/GroupDetailState.dart
@@ -0,0 +1,708 @@
+import 'package:flutter/cupertino.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+import 'package:stacked/stacked.dart';
+
+import '../../about/external/data/Group.dart';
+import '../../about/external/data/GroupGoal.dart';
+import '../../about/external/data/GroupMember.dart';
+import '../../about/external/data/GroupObjective.dart';
+import '../../about/external/initial/NudgeRequest.dart';
+import '../../about/external/initial/ObjectiveProgressRequest.dart';
+import '../../about/internal/application/NotificationType.dart';
+import '../../about/internal/application/TextType.dart';
+import '../../configs/Navigator.dart';
+import '../../designs/Component.dart';
+import '../../designs/MemberAvatar.dart';
+import '../../designs/Responsive.dart';
+import '../../designs/Shell.dart';
+import '../../designs/buttons/Buttons.dart';
+import '../../designs/input/InputFields.dart';
+import '../../designs/text/Text.dart';
+import '../../utils/Colors.dart';
+import '../../utils/CommonUtils.dart';
+import 'ConnectGroupDetail.dart';
+import 'GroupChat.dart';
+import 'GroupDetail.dart';
+import 'GroupGoalEditor.dart';
+import 'ViewGroupDetail.dart';
+
+class GroupDetailState extends State<GroupDetail>
+    implements ConnectGroupDetail {
+  ViewGroupDetail? _model;
+
+  late Group _group;
+
+  /// Members nudged from this screen, so the button reads "Nudged" after.
+  final Set<String> _nudged = <String>{};
+
+  final TextEditingController _amount = TextEditingController();
+
+  final TextEditingController _note = TextEditingController();
+
+  @override
+  void initState() {
+    super.initState();
+    _group = widget.group;
+  }
+
+  @override
+  void dispose() {
+    _amount.dispose();
+    _note.dispose();
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return ViewModelBuilder<ViewGroupDetail>.reactive(
+      viewModelBuilder: () => ViewGroupDetail(context, this),
+      onViewModelReady: (viewModel) {
+        _model = viewModel;
+        _initiate();
+      },
+      builder: (context, viewModel, child) => LayoutBuilder(
+        builder: (BuildContext context, BoxConstraints constraints) {
+          return Responsive(
+            mobile: _mobileView(constraints),
+            tablet: _mobileView(constraints),
+            desktop: _mobileView(constraints),
+          );
+        },
+      ),
+    );
+  }
+
+  void _initiate() {
+    _model?.loadGroup(widget.group.id);
+  }
+
+  Color get _accent => goalColor(_group.colourHex);
+
+  // ── Handlers ──────────────────────────────────────────────────────────────
+
+  void _onBack() {
+    Navigator.pop(context, true);
+  }
+
+  void _onOpenChat() async {
+    await GroundedNavigation()
+        .navigateToPageWithData(GroupChat(group: _group), context);
+    _model?.loadGroup(_group.id, quiet: true);
+  }
+
+  void _onAddGoal() async {
+    final result = await GroundedNavigation()
+        .navigateToPageWithData(GroupGoalEditor(group: _group), context);
+
+    if (result == true) {
+      _model?.loadGroup(_group.id, quiet: true);
+    }
+  }
+
+  void _onCopyCode() async {
+    await Clipboard.setData(ClipboardData(text: _group.inviteCode));
+    _model?.showApplicationNotification(
+      NotificationType.success,
+      "Code copied",
+      "Send ${_group.inviteCode} to whoever should join. They enter it under Groups → Join with a code.",
+      true,
+      true,
+      null,
+    );
+  }
+
+  void _onNudge(GroupMember member) {
+    _model?.nudge(
+        NudgeRequest(groupId: _group.id, memberId: member.id), member.name);
+  }
+
+  void _onNudgeEveryone() {
+    _model?.nudge(NudgeRequest(groupId: _group.id), "everyone");
+  }
+
+  void _onLog(GroupGoal goal, GroupObjective objective) {
+    _amount.text = "";
+    _note.text = "";
+
+    showModalBottomSheet(
+      context: context,
+      isScrollControlled: true,
+      backgroundColor: colorWhite,
+      builder: (sheetContext) => _logSheet(sheetContext, goal, objective),
+    );
+  }
+
+  void _onQuickAmount(double value) {
+    _amount.text = formatAmount(value).replaceAll(",", "");
+  }
+
+  void _onSubmitLog(BuildContext sheetContext, GroupGoal goal,
+      GroupObjective objective) {
+    final double amount = double.tryParse(_amount.text.trim()) ?? 0;
+    if (amount <= 0) {
+      return;
+    }
+
+    Navigator.pop(sheetContext);
+
+    _model?.logProgress(
+      ObjectiveProgressRequest(
+        groupId: _group.id,
+        goalId: goal.id,
+        objectiveId: objective.id,
+        amount: amount,
+        note: _note.text.trim(),
+      ),
+      "${formatAmount(amount)} ${objective.unit} on ${objective.title}",
+    );
+  }
+
+  void _onLeave() {
+    _model?.showApplicationNotification(
+      NotificationType.warning,
+      "Leave ${_group.name}?",
+      "You stop seeing the shared goals and the chat. What you logged stays in the group's totals.",
+      true,
+      true,
+      null,
+      action: "Leave",
+      positiveAction: _onConfirmLeave,
+    );
+  }
+
+  void _onConfirmLeave() {
+    Navigator.pop(context);
+    _model?.leave(_group.id);
+  }
+
+  // ── Views ─────────────────────────────────────────────────────────────────
+
+  Widget _mobileView(BoxConstraints constraints) {
+    final List<GroupMember> ranked = List<GroupMember>.from(_group.members)
+      ..sort((a, b) => b.keptRate.compareTo(a.keptRate));
+
+    return Sheet(
+      eyebrow: "${_group.members.length} members",
+      title: _group.name,
+      onBack: _onBack,
+      scene: goalScene(_accent),
+      sceneSeed: sceneSeed(_group.name),
+      action: chromeAction(CupertinoIcons.chat_bubble_2_fill, _onOpenChat),
+      child: Column(
+        crossAxisAlignment: CrossAxisAlignment.stretch,
+        mainAxisSize: MainAxisSize.min,
+        children: [
+          if (_group.description.isNotEmpty) ...[
+            text(_group.description, 15, TextType.Regular,
+                color: colorGrey2, height: 1.55),
+            const SizedBox(height: 22),
+          ],
+          _statsRow(),
+          const SizedBox(height: 20),
+          _chatCard(),
+          const SizedBox(height: 30),
+          sectionBreak(
+            "Shared goals",
+            caption: "${_group.goals.length} on the go",
+            trailing: textButton("+ Add", _onAddGoal,
+                color: colorInk, textSize: 14, type: TextType.Medium),
+          ),
+          if (_group.goals.isEmpty)
+            emptyState(
+              CupertinoIcons.flag,
+              "Nothing shared yet",
+              "Add a goal and split it into objectives everyone can log toward, like kilometres, pages or sessions.",
+            )
+          else
+            ..._group.goals.map(_goalCard),
+          const SizedBox(height: 30),
+          sectionBreak("Leaderboard",
+              caption: "kept, last 7 days",
+              trailing: textButton("Nudge all", _onNudgeEveryone,
+                  color: colorInk, textSize: 14, type: TextType.Medium)),
+          for (int index = 0; index < ranked.length; index++)
+            _memberRow(index + 1, ranked[index]),
+          const SizedBox(height: 26),
+          Center(
+            child: textButton("Leave group", _onLeave,
+                color: colorDestructive, textSize: 13),
+          ),
+        ],
+      ),
+    );
+  }
+
+  Widget _statsRow() {
+    final double average = _group.members.isEmpty
+        ? 0
+        : _group.members
+                .map((member) => member.keptRate)
+                .reduce((a, b) => a + b) /
+            _group.members.length;
+
+    return card(
+      padding: const EdgeInsets.fromLTRB(20, 18, 12, 18),
+      child: Row(
+        children: [
+          Expanded(
+            child: labelled("Together", "${(_group.progress * 100).round()}%",
+                valueSize: 26, valueType: TextType.Light),
+          ),
+          Expanded(
+            child: labelled("Kept avg", "${(average * 100).round()}%",
+                valueSize: 26, valueType: TextType.Light),
+          ),
+          GestureDetector(
+            onTap: _onCopyCode,
+            behavior: HitTestBehavior.opaque,
+            child: Container(
+              padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 10),
+              color: colorAmbientMid,
+              child: Column(
+                crossAxisAlignment: CrossAxisAlignment.start,
+                mainAxisSize: MainAxisSize.min,
+                children: [
+                  Row(
+                    mainAxisSize: MainAxisSize.min,
+                    children: [
+                      text("INVITE", 9, TextType.Bold,
+                          color: colorGrey2, letterSpacing: 1.0),
+                      const SizedBox(width: 6),
+                      Icon(CupertinoIcons.doc_on_doc,
+                          size: 12, color: colorGrey2),
+                    ],
+                  ),
+                  const SizedBox(height: 4),
+                  text(_group.inviteCode, 18, TextType.Medium,
+                      color: colorInk, letterSpacing: 1.5),
+                ],
+              ),
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+
+  /// The way into the chat: the last line said and how much is unread.
+  Widget _chatCard() {
+    return GestureDetector(
+      onTap: _onOpenChat,
+      child: Container(
+        padding: const EdgeInsets.fromLTRB(20, 18, 16, 18),
+        decoration: const BoxDecoration(
+          gradient: LinearGradient(
+            begin: Alignment.topLeft,
+            end: Alignment.bottomRight,
+            colors: <Color>[colorNightLift, colorNight],
+          ),
+          boxShadow: [
+            BoxShadow(
+              color: Color(0x332A3A30),
+              blurRadius: 24,
+              offset: Offset(0, 10),
+            ),
+          ],
+        ),
+        child: Row(
+          children: [
+            Expanded(
+              child: Column(
+                crossAxisAlignment: CrossAxisAlignment.start,
+                mainAxisSize: MainAxisSize.min,
+                children: [
+                  Row(
+                    children: [
+                      Icon(CupertinoIcons.chat_bubble_2_fill,
+                          size: 16, color: colorLime),
+                      const SizedBox(width: 8),
+                      text("Group chat", 14, TextType.Medium,
+                          color: colorLime),
+                      if (_group.unread > 0) ...[
+                        const SizedBox(width: 10),
+                        Container(
+                          padding: const EdgeInsets.symmetric(
+                              horizontal: 7, vertical: 3),
+                          color: colorLime,
+                          child: text("${_group.unread} new", 10,
+                              TextType.Medium,
+                              color: colorNight),
+                        ),
+                      ],
+                    ],
+                  ),
+                  const SizedBox(height: 10),
+                  text(
+                    _group.lastMessage.isEmpty
+                        ? "Say hello. Check-ins and nudges show up here too."
+                        : "${_group.lastAuthor}: ${_group.lastMessage}",
+                    15,
+                    TextType.Regular,
+                    color: colorWhite,
+                    maxLines: 2,
+                    overflow: TextOverflow.ellipsis,
+                    height: 1.45,
+                  ),
+                ],
+              ),
+            ),
+            const SizedBox(width: 12),
+            Container(
+              width: 46,
+              height: 46,
+              color: colorWhite.withValues(alpha: 0.12),
+              child: Icon(CupertinoIcons.arrow_right,
+                  size: 20, color: colorWhite),
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+
+  /// A shared goal: its overall bar, then each objective with the group's
+  /// total, your share, and a button to log more.
+  Widget _goalCard(GroupGoal goal) {
+    final Color tone =
+        goal.colourHex.isEmpty ? _accent : goalColor(goal.colourHex);
+
+    return Container(
+      margin: const EdgeInsets.only(bottom: 14),
+      child: card(
+        padding: EdgeInsets.zero,
+        child: Column(
+          crossAxisAlignment: CrossAxisAlignment.stretch,
+          mainAxisSize: MainAxisSize.min,
+          children: [
+            Container(height: 6, color: tone),
+            Padding(
+              padding: const EdgeInsets.fromLTRB(20, 18, 20, 6),
+              child: Column(
+                crossAxisAlignment: CrossAxisAlignment.stretch,
+                mainAxisSize: MainAxisSize.min,
+                children: [
+                  Row(
+                    crossAxisAlignment: CrossAxisAlignment.start,
+                    children: [
+                      Expanded(
+                        child: text(goal.title, 19, TextType.Medium,
+                            color: colorInk),
+                      ),
+                      const SizedBox(width: 10),
+                      text("${(goal.progress * 100).round()}%", 22,
+                          TextType.Light,
+                          color: colorInk),
+                    ],
+                  ),
+                  const SizedBox(height: 4),
+                  text(
+                    [
+                      "${goal.completeObjectives}/${goal.objectives.length} objectives met",
+                      goal.targetDate == null
+                          ? "no deadline"
+                          : targetLabel(goal.targetDate),
+                    ].join(" · "),
+                    12,
+                    TextType.Regular,
+                    color: colorGrey2,
+                  ),
+                  const SizedBox(height: 12),
+                  meter(goal.progress,
+                      fill: tone, track: tone.withValues(alpha: 0.14), height: 6),
+                  const SizedBox(height: 8),
+                ],
+              ),
+            ),
+            for (GroupObjective objective in goal.objectives)
+              _objectiveRow(goal, objective, tone),
+          ],
+        ),
+      ),
+    );
+  }
+
+  Widget _objectiveRow(GroupGoal goal, GroupObjective objective, Color tone) {
+    return Container(
+      padding: const EdgeInsets.fromLTRB(20, 14, 14, 16),
+      decoration: BoxDecoration(
+        border: Border(top: BorderSide(color: colorBorder)),
+      ),
+      child: Row(
+        children: [
+          Expanded(
+            child: Column(
+              crossAxisAlignment: CrossAxisAlignment.start,
+              mainAxisSize: MainAxisSize.min,
+              children: [
+                Row(
+                  children: [
+                    if (objective.complete) ...[
+                      Icon(CupertinoIcons.checkmark_seal_fill,
+                          size: 15, color: colorPositive),
+                      const SizedBox(width: 6),
+                    ],
+                    Flexible(
+                      child: text(objective.title, 15, TextType.Medium,
+                          color: colorInk,
+                          maxLines: 1,
+                          overflow: TextOverflow.ellipsis),
+                    ),
+                  ],
+                ),
+                const SizedBox(height: 4),
+                text(
+                  "${formatAmount(objective.current)} / ${formatAmount(objective.target)} ${objective.unit}",
+                  13,
+                  TextType.Regular,
+                  color: colorGrey2,
+                ),
+                const SizedBox(height: 8),
+                meter(objective.progress,
+                    fill: tone, track: tone.withValues(alpha: 0.12), height: 4),
+                const SizedBox(height: 6),
+                text("You: ${formatAmount(objective.mine)} ${objective.unit}",
+                    12, TextType.Medium,
+                    color: tone),
+              ],
+            ),
+          ),
+          const SizedBox(width: 14),
+          GestureDetector(
+            onTap: () => _onLog(goal, objective),
+            child: Container(
+              padding: const EdgeInsets.symmetric(horizontal: 14, vertical: 12),
+              color: colorNight,
+              child: Row(
+                mainAxisSize: MainAxisSize.min,
+                children: [
+                  Icon(CupertinoIcons.add, size: 16, color: colorLime),
+                  const SizedBox(width: 6),
+                  text("Log", 14, TextType.Medium, color: colorWhite),
+                ],
+              ),
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+
+  Widget _memberRow(int rank, GroupMember member) {
+    final bool nudged = _nudged.contains(member.id);
+    final bool quiet = member.lastCheckIn == null ||
+        DateTime.now().difference(member.lastCheckIn!).inHours >= 24;
+
+    return Container(
+      margin: const EdgeInsets.only(bottom: 10),
+      child: card(
+        padding: const EdgeInsets.fromLTRB(14, 12, 12, 12),
+        child: Row(
+          children: [
+            SizedBox(
+              width: 24,
+              child: text("$rank", 16, TextType.Medium,
+                  color: rank == 1 ? colorInk : colorGrey2),
+            ),
+            memberAvatar(member.name, 46),
+            const SizedBox(width: 12),
+            Expanded(
+              child: Column(
+                crossAxisAlignment: CrossAxisAlignment.start,
+                mainAxisSize: MainAxisSize.min,
+                children: [
+                  Row(
+                    children: [
+                      Flexible(
+                        child: text(
+                            member.me ? "${member.name} (you)" : member.name,
+                            16,
+                            TextType.Medium,
+                            color: colorInk,
+                            maxLines: 1,
+                            overflow: TextOverflow.ellipsis),
+                      ),
+                      if (member.owner) ...[
+                        const SizedBox(width: 6),
+                        Icon(CupertinoIcons.star_fill,
+                            size: 12, color: colorBarStandard),
+                      ],
+                    ],
+                  ),
+                  const SizedBox(height: 4),
+                  Row(
+                    children: [
+                      Icon(CupertinoIcons.flame_fill,
+                          size: 12, color: colorBarNonNegotiable),
+                      const SizedBox(width: 3),
+                      text("${member.streak}d", 12, TextType.Regular,
+                          color: colorGrey2),
+                      const SizedBox(width: 10),
+                      text(
+                        quiet
+                            ? "quiet ${member.lastCheckIn == null ? "" : _ago(member.lastCheckIn!)}"
+                            : "checked in ${_ago(member.lastCheckIn!)}",
+                        12,
+                        TextType.Regular,
+                        color: quiet ? colorStandingGrounded : colorGrey2,
+                      ),
+                    ],
+                  ),
+                ],
+              ),
+            ),
+            text("${(member.keptRate * 100).round()}%", 20, TextType.Light,
+                color: colorInk),
+            if (!member.me) ...[
+              const SizedBox(width: 10),
+              GestureDetector(
+                onTap: nudged ? null : () => _onNudge(member),
+                child: Container(
+                  width: 44,
+                  height: 44,
+                  color: nudged ? colorAmbientMid : colorNight,
+                  child: Icon(
+                    nudged
+                        ? CupertinoIcons.checkmark
+                        : CupertinoIcons.hand_point_right_fill,
+                    size: 18,
+                    color: nudged ? colorGrey2 : colorLime,
+                  ),
+                ),
+              ),
+            ],
+          ],
+        ),
+      ),
+    );
+  }
+
+  /// Log progress: an amount (with one-tap presets that suit the unit) and
+  /// an optional note that rides along into the chat.
+  Widget _logSheet(BuildContext sheetContext, GroupGoal goal,
+      GroupObjective objective) {
+    final List<double> presets = _presets(objective.unit);
+
+    return Padding(
+      padding: EdgeInsets.fromLTRB(20, 16, 20,
+          MediaQuery.of(sheetContext).viewInsets.bottom + 28),
+      child: Column(
+        crossAxisAlignment: CrossAxisAlignment.stretch,
+        mainAxisSize: MainAxisSize.min,
+        children: [
+          Center(child: Container(width: 40, height: 4, color: colorGrabber)),
+          const SizedBox(height: 18),
+          text("LOG PROGRESS", 10, TextType.Bold,
+              color: colorGrey2, letterSpacing: 1.2),
+          const SizedBox(height: 6),
+          text(objective.title, 24, TextType.Medium, color: colorInk),
+          const SizedBox(height: 4),
+          text(
+              "${formatAmount(objective.current)} of ${formatAmount(objective.target)} ${objective.unit} so far",
+              13,
+              TextType.Regular,
+              color: colorGrey2),
+          const SizedBox(height: 18),
+          Row(
+            children: [
+              for (double preset in presets) ...[
+                Expanded(
+                  child: GestureDetector(
+                    onTap: () => _onQuickAmount(preset),
+                    child: Container(
+                      padding: const EdgeInsets.symmetric(vertical: 14),
+                      alignment: Alignment.center,
+                      color: colorAmbientMid,
+                      child: text("+${formatAmount(preset)}", 15,
+                          TextType.Medium,
+                          color: colorInk),
+                    ),
+                  ),
+                ),
+                if (preset != presets.last) const SizedBox(width: 8),
+              ],
+            ],
+          ),
+          const SizedBox(height: 16),
+          inputField(
+            "Amount (${objective.unit})",
+            _amount,
+            hint: "How much?",
+            keyboard: const TextInputType.numberWithOptions(decimal: true),
+            formatters: <TextInputFormatter>[
+              FilteringTextInputFormatter.allow(RegExp(r"[0-9.]")),
+            ],
+          ),
+          const SizedBox(height: 14),
+          inputField("Note", _note, hint: "Optional: posted with the check-in"),
+          const SizedBox(height: 22),
+          roundedCornerButton("Log it",
+              () => _onSubmitLog(sheetContext, goal, objective),
+              icon: CupertinoIcons.checkmark),
+        ],
+      ),
+    );
+  }
+
+  List<double> _presets(String unit) {
+    switch (unit.toLowerCase()) {
+      case "steps":
+        return <double>[1000, 5000, 10000];
+      case "words":
+        return <double>[250, 500, 1000];
+      case "hours":
+        return <double>[0.5, 1, 2];
+      case "km":
+        return <double>[3, 5, 10];
+      default:
+        return <double>[1, 2, 5];
+    }
+  }
+
+  String _ago(DateTime moment) {
+    final Duration gap = DateTime.now().difference(moment);
+    if (gap.inMinutes < 60) return "${gap.inMinutes.clamp(1, 59)}m ago";
+    if (gap.inHours < 24) return "${gap.inHours}h ago";
+    return "${gap.inDays}d ago";
+  }
+
+  // ── ConnectGroupDetail ────────────────────────────────────────────────────
+
+  @override
+  void onGroupLoaded(Group group) {
+    setState(() {
+      _group = group;
+    });
+  }
+
+  @override
+  void onProgressLogged(Group group, String summary) {
+    setState(() {
+      _group = group;
+    });
+    _model?.showApplicationNotification(
+      NotificationType.success,
+      "Logged",
+      "$summary. The group sees it in the chat.",
+      true,
+      true,
+      null,
+    );
+  }
+
+  @override
+  void onNudged(String who) {
+    setState(() {
+      for (GroupMember member in _group.members) {
+        if (who == "everyone" ? !member.me : member.name == who) {
+          _nudged.add(member.id);
+        }
+      }
+    });
+  }
+
+  @override
+  void onLeft() {
+    Navigator.pop(context, true);
+  }
+}
diff --git a/frontend/lib/Grounded/see/group/GroupEditor.dart b/frontend/lib/Grounded/see/group/GroupEditor.dart
new file mode 100644
index 0000000..2d99c97
--- /dev/null
+++ b/frontend/lib/Grounded/see/group/GroupEditor.dart
@@ -0,0 +1,12 @@
+import 'package:flutter/material.dart';
+
+import 'GroupEditorState.dart';
+
+class GroupEditor extends StatefulWidget {
+  final bool joining;
+
+  const GroupEditor({super.key, this.joining = false});
+
+  @override
+  State<GroupEditor> createState() => GroupEditorState();
+}
diff --git a/frontend/lib/Grounded/see/group/GroupEditorState.dart b/frontend/lib/Grounded/see/group/GroupEditorState.dart
new file mode 100644
index 0000000..25e71ab
--- /dev/null
+++ b/frontend/lib/Grounded/see/group/GroupEditorState.dart
@@ -0,0 +1,293 @@
+import 'package:flutter/cupertino.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+import 'package:stacked/stacked.dart';
+
+import '../../about/external/data/Group.dart';
+import '../../about/external/initial/GroupRequest.dart';
+import '../../about/external/initial/JoinGroupRequest.dart';
+import '../../about/internal/application/TextType.dart';
+import '../../designs/MemberAvatar.dart';
+import '../../designs/Responsive.dart';
+import '../../designs/Shell.dart';
+import '../../designs/buttons/Buttons.dart';
+import '../../designs/input/InputFields.dart';
+import '../../designs/text/Text.dart';
+import '../../utils/Colors.dart';
+import '../../utils/Validators.dart';
+import 'ConnectGroupEditor.dart';
+import 'GroupEditor.dart';
+import 'ViewGroupEditor.dart';
+
+class GroupEditorState extends State<GroupEditor>
+    implements ConnectGroupEditor {
+  ViewGroupEditor? _model;
+
+  final GlobalKey<FormState> _formKey = GlobalKey<FormState>();
+
+  final TextEditingController _name = TextEditingController();
+
+  final TextEditingController _description = TextEditingController();
+
+  final TextEditingController _code = TextEditingController();
+
+  Color _accent = goalAccents[1];
+
+  bool _joining = false;
+
+  @override
+  void initState() {
+    super.initState();
+    _joining = widget.joining;
+  }
+
+  @override
+  void dispose() {
+    _name.dispose();
+    _description.dispose();
+    _code.dispose();
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return ViewModelBuilder<ViewGroupEditor>.reactive(
+      viewModelBuilder: () => ViewGroupEditor(context, this),
+      onViewModelReady: (viewModel) {
+        _model = viewModel;
+        _initiate();
+      },
+      builder: (context, viewModel, child) => LayoutBuilder(
+        builder: (BuildContext context, BoxConstraints constraints) {
+          return Responsive(
+            mobile: _mobileView(constraints),
+            tablet: _mobileView(constraints),
+            desktop: _mobileView(constraints),
+          );
+        },
+      ),
+    );
+  }
+
+  void _initiate() {}
+
+  // ── Handlers ──────────────────────────────────────────────────────────────
+
+  void _onBack() {
+    Navigator.pop(context, false);
+  }
+
+  void _onModeSelected(String mode) {
+    setState(() {
+      _joining = mode == "Join";
+    });
+  }
+
+  void _onNameChanged(String value) {
+    setState(() {});
+  }
+
+  void _onAccentSelected(Color colour) {
+    setState(() {
+      _accent = colour;
+    });
+  }
+
+  void _onSubmit() {
+    if (_formKey.currentState?.validate() != true) {
+      return;
+    }
+
+    if (_joining) {
+      _model?.join(JoinGroupRequest(inviteCode: _code.text.trim().toUpperCase()));
+    } else {
+      _model?.create(GroupRequest(
+        name: _name.text.trim(),
+        description: _description.text.trim(),
+        colourHex: colorToHex(_accent),
+      ));
+    }
+  }
+
+  String? _validateCode(String? value) {
+    final String code = (value ?? "").trim();
+    if (code.length != 6) {
+      return "Invite codes are six characters.";
+    }
+    return null;
+  }
+
+  // ── Views ─────────────────────────────────────────────────────────────────
+
+  Widget _mobileView(BoxConstraints constraints) {
+    return Sheet(
+      eyebrow: _joining ? "Join" : "New",
+      title: "Group",
+      onBack: _onBack,
+      child: Form(
+        key: _formKey,
+        child: Column(
+          crossAxisAlignment: CrossAxisAlignment.stretch,
+          mainAxisSize: MainAxisSize.min,
+          children: [
+            displayTitle(_joining
+                ? "Got a code?"
+                : "Who's keeping\nyou honest?"),
+            const SizedBox(height: 22),
+            segmentedSelector<String>(
+              options: const <String>["Create", "Join"],
+              selected: _joining ? "Join" : "Create",
+              label: _modeLabel,
+              onSelected: _onModeSelected,
+              activeColor: colorNight,
+            ),
+            const SizedBox(height: 26),
+            if (_joining) ..._joinFields() else ..._createFields(),
+            const SizedBox(height: 32),
+            roundedCornerButton(
+              _joining ? "Join group" : "Create group",
+              _onSubmit,
+              icon: _joining ? CupertinoIcons.arrow_right : CupertinoIcons.add,
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+
+  String _modeLabel(String mode) => mode;
+
+  List<Widget> _createFields() {
+    return <Widget>[
+      _preview(),
+      const SizedBox(height: 26),
+      inputField(
+        "Group name",
+        _name,
+        hint: "Morning Crew, Thesis Sprint…",
+        validator: Validators.title,
+        onChanged: _onNameChanged,
+      ),
+      const SizedBox(height: 16),
+      inputField(
+        "What it's for",
+        _description,
+        hint: "Optional: the promise you're all making",
+        maxLines: 3,
+      ),
+      const SizedBox(height: 26),
+      sectionBreak("Colour", caption: "the group's banner"),
+      _swatches(),
+      const SizedBox(height: 14),
+      text(
+        "You'll get a six-letter invite code to send to the others once it's created.",
+        12,
+        TextType.Regular,
+        color: colorGrey2,
+        height: 1.5,
+      ),
+    ];
+  }
+
+  List<Widget> _joinFields() {
+    return <Widget>[
+      inputField(
+        "Invite code",
+        _code,
+        hint: "6 characters, like MRN7AM",
+        validator: _validateCode,
+        icon: CupertinoIcons.ticket,
+        formatters: <TextInputFormatter>[
+          LengthLimitingTextInputFormatter(6),
+          FilteringTextInputFormatter.allow(RegExp(r"[A-Za-z0-9]")),
+        ],
+      ),
+      const SizedBox(height: 12),
+      text(
+        "Ask whoever started the group: the code is on the group's page. Joining shows you their shared goals and the chat straight away.",
+        12,
+        TextType.Regular,
+        color: colorGrey2,
+        height: 1.5,
+      ),
+    ];
+  }
+
+  /// The banner as it will look, so the colour is chosen by seeing it.
+  Widget _preview() {
+    final String name =
+        _name.text.trim().isEmpty ? "Your group" : _name.text.trim();
+
+    return Container(
+      padding: const EdgeInsets.all(20),
+      decoration: BoxDecoration(
+        gradient: LinearGradient(
+          begin: Alignment.topLeft,
+          end: Alignment.bottomRight,
+          colors: <Color>[_accent, Color.lerp(_accent, colorBlack, 0.45)!],
+        ),
+      ),
+      child: Column(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        mainAxisSize: MainAxisSize.min,
+        children: [
+          Row(
+            children: [
+              Icon(CupertinoIcons.person_3_fill,
+                  size: 16, color: colorWhite.withValues(alpha: 0.7)),
+              const SizedBox(width: 8),
+              text("1 MEMBER", 9, TextType.Bold,
+                  color: colorWhite.withValues(alpha: 0.6),
+                  letterSpacing: 1.2),
+            ],
+          ),
+          const SizedBox(height: 14),
+          text(name, 26, TextType.Light,
+              color: colorWhite, maxLines: 2, overflow: TextOverflow.ellipsis),
+          const SizedBox(height: 16),
+          avatarStack(const <String>["Alex"], 34),
+        ],
+      ),
+    );
+  }
+
+  Widget _swatches() {
+    return Wrap(
+      spacing: 9,
+      runSpacing: 9,
+      children: goalAccents.map((colour) {
+        final bool selected = colour.toARGB32() == _accent.toARGB32();
+
+        return GestureDetector(
+          onTap: () => _onAccentSelected(colour),
+          child: AnimatedContainer(
+            duration: const Duration(milliseconds: 150),
+            width: 40,
+            height: 40,
+            alignment: Alignment.center,
+            decoration: BoxDecoration(
+              color: colour,
+              border: Border.all(
+                color: selected ? colorWhite : Colors.transparent,
+                width: 3,
+              ),
+              boxShadow: selected
+                  ? [BoxShadow(color: colour, spreadRadius: 1.5)]
+                  : null,
+            ),
+            child: selected
+                ? Icon(Icons.check_rounded, size: 18, color: colorWhite)
+                : null,
+          ),
+        );
+      }).toList(),
+    );
+  }
+
+  // ── ConnectGroupEditor ────────────────────────────────────────────────────
+
+  @override
+  void onGroupReady(Group group) {
+    Navigator.pop(context, group);
+  }
+}
diff --git a/frontend/lib/Grounded/see/group/GroupGoalEditor.dart b/frontend/lib/Grounded/see/group/GroupGoalEditor.dart
new file mode 100644
index 0000000..8cc1098
--- /dev/null
+++ b/frontend/lib/Grounded/see/group/GroupGoalEditor.dart
@@ -0,0 +1,13 @@
+import 'package:flutter/material.dart';
+
+import '../../about/external/data/Group.dart';
+import 'GroupGoalEditorState.dart';
+
+class GroupGoalEditor extends StatefulWidget {
+  final Group group;
+
+  const GroupGoalEditor({super.key, required this.group});
+
+  @override
+  State<GroupGoalEditor> createState() => GroupGoalEditorState();
+}
diff --git a/frontend/lib/Grounded/see/group/GroupGoalEditorState.dart b/frontend/lib/Grounded/see/group/GroupGoalEditorState.dart
new file mode 100644
index 0000000..a16079f
--- /dev/null
+++ b/frontend/lib/Grounded/see/group/GroupGoalEditorState.dart
@@ -0,0 +1,317 @@
+import 'package:flutter/cupertino.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+import 'package:stacked/stacked.dart';
+
+import '../../about/external/initial/GroupGoalRequest.dart';
+import '../../about/external/initial/ObjectiveDraft.dart';
+import '../../about/internal/application/TextType.dart';
+import '../../designs/Component.dart';
+import '../../designs/Responsive.dart';
+import '../../designs/Shell.dart';
+import '../../designs/buttons/Buttons.dart';
+import '../../designs/input/InputFields.dart';
+import '../../designs/text/Text.dart';
+import '../../utils/Colors.dart';
+import '../../utils/CommonUtils.dart';
+import '../../utils/Validators.dart';
+import 'ConnectGroupGoalEditor.dart';
+import 'GroupGoalEditor.dart';
+import 'ViewGroupGoalEditor.dart';
+
+/// The three fields of one objective while it is being typed.
+typedef _ObjectiveFields = ({
+  TextEditingController title,
+  TextEditingController target,
+  TextEditingController unit,
+});
+
+class GroupGoalEditorState extends State<GroupGoalEditor>
+    implements ConnectGroupGoalEditor {
+  ViewGroupGoalEditor? _model;
+
+  final GlobalKey<FormState> _formKey = GlobalKey<FormState>();
+
+  final TextEditingController _title = TextEditingController();
+
+  final TextEditingController _description = TextEditingController();
+
+  final List<_ObjectiveFields> _objectives = <_ObjectiveFields>[];
+
+  DateTime? _targetDate;
+
+  @override
+  void initState() {
+    super.initState();
+    _objectives.add(_blankObjective());
+  }
+
+  @override
+  void dispose() {
+    _title.dispose();
+    _description.dispose();
+    for (_ObjectiveFields fields in _objectives) {
+      fields.title.dispose();
+      fields.target.dispose();
+      fields.unit.dispose();
+    }
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return ViewModelBuilder<ViewGroupGoalEditor>.reactive(
+      viewModelBuilder: () => ViewGroupGoalEditor(context, this),
+      onViewModelReady: (viewModel) {
+        _model = viewModel;
+        _initiate();
+      },
+      builder: (context, viewModel, child) => LayoutBuilder(
+        builder: (BuildContext context, BoxConstraints constraints) {
+          return Responsive(
+            mobile: _mobileView(constraints),
+            tablet: _mobileView(constraints),
+            desktop: _mobileView(constraints),
+          );
+        },
+      ),
+    );
+  }
+
+  void _initiate() {}
+
+  _ObjectiveFields _blankObjective() {
+    return (
+      title: TextEditingController(),
+      target: TextEditingController(),
+      unit: TextEditingController(),
+    );
+  }
+
+  // ── Handlers ──────────────────────────────────────────────────────────────
+
+  void _onBack() {
+    Navigator.pop(context, false);
+  }
+
+  void _onAddObjective() {
+    setState(() {
+      _objectives.add(_blankObjective());
+    });
+  }
+
+  void _onRemoveObjective(_ObjectiveFields fields) {
+    setState(() {
+      _objectives.remove(fields);
+    });
+    fields.title.dispose();
+    fields.target.dispose();
+    fields.unit.dispose();
+  }
+
+  void _onPickTarget() async {
+    final DateTime now = DateTime.now();
+    final DateTime? picked = await showDatePicker(
+      context: context,
+      initialDate: _targetDate ?? now.add(const Duration(days: 30)),
+      firstDate: now,
+      lastDate: now.add(const Duration(days: 365 * 3)),
+    );
+
+    if (picked == null) {
+      return;
+    }
+
+    setState(() {
+      _targetDate = picked;
+    });
+  }
+
+  void _onClearTarget() {
+    setState(() {
+      _targetDate = null;
+    });
+  }
+
+  void _onSave() {
+    if (_formKey.currentState?.validate() != true) {
+      return;
+    }
+
+    _model?.save(GroupGoalRequest(
+      groupId: widget.group.id,
+      title: _title.text.trim(),
+      description: _description.text.trim(),
+      targetDate: _targetDate?.toIso8601String() ?? "",
+      colourHex: widget.group.colourHex,
+      objectives: _objectives
+          .map((fields) => ObjectiveDraft(
+                title: fields.title.text.trim(),
+                unit: fields.unit.text.trim(),
+                target: double.tryParse(fields.target.text.trim()) ?? 0,
+              ))
+          .toList(),
+    ));
+  }
+
+  String? _validateTarget(String? value) {
+    final double? target = double.tryParse((value ?? "").trim());
+    if (target == null || target <= 0) {
+      return "A number above 0.";
+    }
+    return null;
+  }
+
+  String? _validateUnit(String? value) {
+    return Validators.required(value, "Unit");
+  }
+
+  // ── Views ─────────────────────────────────────────────────────────────────
+
+  Widget _mobileView(BoxConstraints constraints) {
+    return Sheet(
+      eyebrow: widget.group.name,
+      title: "Shared goal",
+      onBack: _onBack,
+      child: Form(
+        key: _formKey,
+        child: Column(
+          crossAxisAlignment: CrossAxisAlignment.stretch,
+          mainAxisSize: MainAxisSize.min,
+          children: [
+            displayTitle("What are you\nall going for?"),
+            const SizedBox(height: 24),
+            inputField(
+              "Goal",
+              _title,
+              hint: "Run 200 km this month, finish the drafts…",
+              validator: Validators.title,
+            ),
+            const SizedBox(height: 16),
+            inputField(
+              "Why it matters",
+              _description,
+              hint: "Optional",
+              maxLines: 2,
+            ),
+            const SizedBox(height: 28),
+            sectionBreak("Objectives",
+                caption: "what everyone logs toward"),
+            text(
+              "Break the goal into numbers people can add to: kilometres, sessions, pages, hours. Each member logs their share and the totals add up.",
+              12,
+              TextType.Regular,
+              color: colorGrey2,
+              height: 1.5,
+            ),
+            const SizedBox(height: 14),
+            for (int index = 0; index < _objectives.length; index++)
+              _objectiveEditor(index, _objectives[index]),
+            outlinedActionButton("Add objective", _onAddObjective,
+                icon: CupertinoIcons.add),
+            const SizedBox(height: 28),
+            sectionBreak("Deadline", caption: "optional"),
+            Row(
+              crossAxisAlignment: CrossAxisAlignment.end,
+              children: [
+                Expanded(
+                  child: selectField(
+                    "Target date",
+                    _targetDate == null ? "" : formatDate(_targetDate),
+                    _onPickTarget,
+                    hint: "No deadline",
+                    icon: CupertinoIcons.calendar,
+                  ),
+                ),
+                if (_targetDate != null) ...[
+                  const SizedBox(width: 8),
+                  iconButton(
+                    Icon(CupertinoIcons.xmark, size: 15, color: colorGrey2),
+                    _onClearTarget,
+                    bordered: true,
+                    background: colorWhite,
+                    size: 50,
+                  ),
+                ],
+              ],
+            ),
+            const SizedBox(height: 32),
+            roundedCornerButton("Share with the group", _onSave,
+                icon: CupertinoIcons.person_3_fill),
+          ],
+        ),
+      ),
+    );
+  }
+
+  Widget _objectiveEditor(int index, _ObjectiveFields fields) {
+    return Container(
+      margin: const EdgeInsets.only(bottom: 12),
+      child: card(
+        padding: const EdgeInsets.fromLTRB(16, 12, 8, 16),
+        child: Column(
+          crossAxisAlignment: CrossAxisAlignment.stretch,
+          mainAxisSize: MainAxisSize.min,
+          children: [
+            Row(
+              children: [
+                text("OBJECTIVE ${index + 1}", 10, TextType.Bold,
+                    color: colorGrey2, letterSpacing: 1.0),
+                const Spacer(),
+                if (_objectives.length > 1)
+                  iconButton(
+                    Icon(CupertinoIcons.xmark, size: 15, color: colorGrey2),
+                    () => _onRemoveObjective(fields),
+                    size: 36,
+                  ),
+              ],
+            ),
+            const SizedBox(height: 6),
+            Padding(
+              padding: const EdgeInsets.only(right: 8),
+              child: Column(
+                crossAxisAlignment: CrossAxisAlignment.stretch,
+                mainAxisSize: MainAxisSize.min,
+                children: [
+                  inputField("Name", fields.title,
+                      hint: "Distance run", validator: Validators.title),
+                  const SizedBox(height: 12),
+                  Row(
+                    crossAxisAlignment: CrossAxisAlignment.start,
+                    children: [
+                      Expanded(
+                        child: inputField(
+                          "Target",
+                          fields.target,
+                          hint: "200",
+                          validator: _validateTarget,
+                          keyboard: const TextInputType.numberWithOptions(
+                              decimal: true),
+                          formatters: <TextInputFormatter>[
+                            FilteringTextInputFormatter.allow(RegExp(r"[0-9.]")),
+                          ],
+                        ),
+                      ),
+                      const SizedBox(width: 10),
+                      Expanded(
+                        child: inputField("Unit", fields.unit,
+                            hint: "km", validator: _validateUnit),
+                      ),
+                    ],
+                  ),
+                ],
+              ),
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+
+  // ── ConnectGroupGoalEditor ────────────────────────────────────────────────
+
+  @override
+  void onGoalSaved() {
+    Navigator.pop(context, true);
+  }
+}
diff --git a/frontend/lib/Grounded/see/group/Groups.dart b/frontend/lib/Grounded/see/group/Groups.dart
new file mode 100644
index 0000000..8cd2fb9
--- /dev/null
+++ b/frontend/lib/Grounded/see/group/Groups.dart
@@ -0,0 +1,10 @@
+import 'package:flutter/material.dart';
+
+import 'GroupsState.dart';
+
+class Groups extends StatefulWidget {
+  const Groups({super.key});
+
+  @override
+  State<Groups> createState() => GroupsState();
+}
diff --git a/frontend/lib/Grounded/see/group/GroupsState.dart b/frontend/lib/Grounded/see/group/GroupsState.dart
new file mode 100644
index 0000000..141da41
--- /dev/null
+++ b/frontend/lib/Grounded/see/group/GroupsState.dart
@@ -0,0 +1,241 @@
+import 'package:flutter/cupertino.dart';
+import 'package:stacked/stacked.dart';
+
+import '../../about/external/data/Group.dart';
+import '../../about/internal/application/TextType.dart';
+import '../../configs/Navigator.dart';
+import '../../designs/Component.dart';
+import '../../designs/GlassSurface.dart';
+import '../../designs/MemberAvatar.dart';
+import '../../designs/Responsive.dart';
+import '../../designs/Shell.dart';
+import '../../designs/buttons/Buttons.dart';
+import '../../designs/scene/SceneArt.dart';
+import '../../designs/text/Text.dart';
+import '../../utils/Colors.dart';
+import '../../utils/CommonUtils.dart';
+import 'ConnectGroups.dart';
+import 'GroupDetail.dart';
+import 'GroupEditor.dart';
+import 'Groups.dart';
+import 'ViewGroups.dart';
+
+class GroupsState extends State<Groups> implements ConnectGroups {
+  ViewGroups? _model;
+
+  List<Group> _groups = <Group>[];
+
+  @override
+  Widget build(BuildContext context) {
+    return ViewModelBuilder<ViewGroups>.reactive(
+      viewModelBuilder: () => ViewGroups(context, this),
+      onViewModelReady: (viewModel) {
+        _model = viewModel;
+        _initiate();
+      },
+      builder: (context, viewModel, child) => LayoutBuilder(
+        builder: (BuildContext context, BoxConstraints constraints) {
+          return Responsive(
+            mobile: _mobileView(constraints),
+            tablet: _mobileView(constraints),
+            desktop: _mobileView(constraints),
+          );
+        },
+      ),
+    );
+  }
+
+  void _initiate() {
+    _model?.loadGroups();
+  }
+
+  // ── Handlers ──────────────────────────────────────────────────────────────
+
+  void _onBack() {
+    Navigator.pop(context, true);
+  }
+
+  void _onOpenGroup(Group group) async {
+    await GroundedNavigation()
+        .navigateToPageWithData(GroupDetail(group: group), context);
+    _model?.loadGroups();
+  }
+
+  void _onNewGroup() {
+    _openEditor(false);
+  }
+
+  void _onJoinGroup() {
+    _openEditor(true);
+  }
+
+  /// Created or joined, you land straight in the group.
+  void _openEditor(bool joining) async {
+    final result = await GroundedNavigation()
+        .navigateToPageWithData(GroupEditor(joining: joining), context);
+
+    if (result is Group) {
+      _model?.loadGroups();
+      _onOpenGroup(result);
+    }
+  }
+
+  // ── Views ─────────────────────────────────────────────────────────────────
+
+  Widget _mobileView(BoxConstraints constraints) {
+    return Sheet(
+      eyebrow: "Grounded",
+      title: "Groups",
+      onBack: _onBack,
+      action: chromeAction(CupertinoIcons.add, _onNewGroup),
+      child: Column(
+        crossAxisAlignment: CrossAxisAlignment.stretch,
+        mainAxisSize: MainAxisSize.min,
+        children: [
+          displayTitle("Keep each other\nhonest."),
+          const SizedBox(height: 14),
+          text(
+            "Share goals with people who will notice when you slip. Everyone logs toward the same objectives, and the chat sees every check-in.",
+            14,
+            TextType.Regular,
+            color: colorGrey2,
+            height: 1.55,
+          ),
+          const SizedBox(height: 28),
+          if (_groups.isEmpty)
+            emptyState(
+              CupertinoIcons.person_3,
+              "No groups yet",
+              "Start one and send the code to a friend, or join with a code someone sent you.",
+            )
+          else
+            ..._groups.map(_groupCard),
+          const SizedBox(height: 24),
+          roundedCornerButton("New group", _onNewGroup,
+              icon: CupertinoIcons.add),
+          const SizedBox(height: 10),
+          outlinedActionButton("Join with a code", _onJoinGroup,
+              icon: CupertinoIcons.ticket),
+        ],
+      ),
+    );
+  }
+
+  /// The group as a painted card: who is in it, how the shared goals are
+  /// going, and the latest line from the chat.
+  Widget _groupCard(Group group) {
+    final Color accent = goalColor(group.colourHex);
+    final Color soft = colorWhite.withValues(alpha: 0.78);
+
+    return GestureDetector(
+      onTap: () => _onOpenGroup(group),
+      child: Container(
+        height: 250,
+        margin: const EdgeInsets.only(bottom: 14),
+        decoration: const BoxDecoration(
+          boxShadow: [
+            BoxShadow(
+              color: Color(0x262A3A30),
+              blurRadius: 24,
+              offset: Offset(0, 10),
+            ),
+          ],
+        ),
+        child: Stack(
+          fit: StackFit.expand,
+          children: [
+            SceneArt(
+              palette: goalScene(accent),
+              seed: sceneSeed(group.name),
+              figure: CupertinoIcons.person_3_fill,
+              figureScale: 0.42,
+              figureAlignment: const Alignment(0.7, -0.4),
+              shade: true,
+            ),
+            Padding(
+              padding: const EdgeInsets.all(16),
+              child: Column(
+                crossAxisAlignment: CrossAxisAlignment.start,
+                children: [
+                  Row(
+                    children: [
+                      GlassSurface(
+                        onDark: true,
+                        padding: const EdgeInsets.symmetric(
+                            horizontal: 10, vertical: 6),
+                        child: text(
+                          "${group.members.length} members · ${group.goals.length} shared goal${group.goals.length == 1 ? "" : "s"}",
+                          11,
+                          TextType.Medium,
+                          color: colorWhite,
+                        ),
+                      ),
+                      const Spacer(),
+                      if (group.unread > 0)
+                        Container(
+                          padding: const EdgeInsets.symmetric(
+                              horizontal: 10, vertical: 6),
+                          color: colorLime,
+                          child: Row(
+                            mainAxisSize: MainAxisSize.min,
+                            children: [
+                              Icon(CupertinoIcons.chat_bubble_fill,
+                                  size: 12, color: colorNight),
+                              const SizedBox(width: 6),
+                              text("${group.unread} new", 11, TextType.Medium,
+                                  color: colorNight),
+                            ],
+                          ),
+                        ),
+                    ],
+                  ),
+                  const Spacer(),
+                  text(group.name, 24, TextType.Medium,
+                      color: colorWhite,
+                      maxLines: 1,
+                      overflow: TextOverflow.ellipsis),
+                  if (group.lastMessage.isNotEmpty) ...[
+                    const SizedBox(height: 4),
+                    text("${group.lastAuthor}: ${group.lastMessage}", 13,
+                        TextType.Regular,
+                        color: soft,
+                        maxLines: 1,
+                        overflow: TextOverflow.ellipsis),
+                  ],
+                  const SizedBox(height: 14),
+                  meter(group.progress,
+                      fill: colorLime,
+                      track: colorWhite.withValues(alpha: 0.25),
+                      height: 6),
+                  const SizedBox(height: 12),
+                  Row(
+                    children: [
+                      avatarStack(
+                          group.members.map((member) => member.name).toList(),
+                          32),
+                      const Spacer(),
+                      text("${(group.progress * 100).round()}%", 22,
+                          TextType.Light,
+                          color: colorWhite),
+                      const SizedBox(width: 6),
+                      text("together", 12, TextType.Regular, color: soft),
+                    ],
+                  ),
+                ],
+              ),
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+
+  // ── ConnectGroups ─────────────────────────────────────────────────────────
+
+  @override
+  void onGroupsLoaded(List<Group> groups) {
+    setState(() {
+      _groups = groups;
+    });
+  }
+}
diff --git a/frontend/lib/Grounded/see/group/ViewGroupChat.dart b/frontend/lib/Grounded/see/group/ViewGroupChat.dart
new file mode 100644
index 0000000..3d9a5e6
--- /dev/null
+++ b/frontend/lib/Grounded/see/group/ViewGroupChat.dart
@@ -0,0 +1,53 @@
+import '../../about/external/data/GroupMessage.dart';
+import '../../about/external/initial/GroupMessageRequest.dart';
+import '../../about/external/initial/IdRequest.dart';
+import '../../utils/ObjectConvertors.dart';
+import '../parent/ParentViewModel.dart';
+import 'ConnectGroupChat.dart';
+
+class ViewGroupChat extends ParentViewModel {
+  ConnectGroupChat connection;
+
+  ViewGroupChat(super.context, this.connection);
+
+  void loadMessages(String groupId) async {
+    if (!await hasNetwork(() => loadMessages(groupId))) return;
+
+    showLoading("Opening the chat");
+
+    try {
+      final response =
+          await getDataManager().getGroupMessages(IdRequest(id: groupId));
+
+      closeLoading();
+
+      connection.onMessagesLoaded(getGroupMessageList(response.data));
+    } catch (e) {
+      handleError(e, () => loadMessages(groupId), () => dismissError(), "Retry");
+    }
+  }
+
+  /// The background refresh while the chat is open. Silent either way — a
+  /// missed poll is picked up by the next one.
+  void refresh(String groupId) async {
+    try {
+      final response =
+          await getDataManager().getGroupMessages(IdRequest(id: groupId));
+
+      connection.onMessagesLoaded(getGroupMessageList(response.data));
+    } catch (e) {
+      // Next tick tries again.
+    }
+  }
+
+  void send(GroupMessageRequest request) async {
+    try {
+      final response = await getDataManager().sendGroupMessage(request);
+
+      connection.onMessageSent(GroupMessage.fromJson(response.data));
+    } catch (e) {
+      connection.onSendFailed(request.body);
+      handleError(e, () => send(request), () => dismissError(), "Retry");
+    }
+  }
+}
diff --git a/frontend/lib/Grounded/see/group/ViewGroupDetail.dart b/frontend/lib/Grounded/see/group/ViewGroupDetail.dart
new file mode 100644
index 0000000..e0797b0
--- /dev/null
+++ b/frontend/lib/Grounded/see/group/ViewGroupDetail.dart
@@ -0,0 +1,77 @@
+import '../../about/external/data/Group.dart';
+import '../../about/external/initial/IdRequest.dart';
+import '../../about/external/initial/NudgeRequest.dart';
+import '../../about/external/initial/ObjectiveProgressRequest.dart';
+import '../parent/ParentViewModel.dart';
+import 'ConnectGroupDetail.dart';
+
+class ViewGroupDetail extends ParentViewModel {
+  ConnectGroupDetail connection;
+
+  ViewGroupDetail(super.context, this.connection);
+
+  /// [quiet] refreshes behind the screen without the loading overlay, for
+  /// coming back from the chat or the goal editor.
+  void loadGroup(String groupId, {bool quiet = false}) async {
+    if (!await hasNetwork(() => loadGroup(groupId, quiet: quiet))) return;
+
+    if (!quiet) showLoading("Loading the group");
+
+    try {
+      final response =
+          await getDataManager().getGroupEntry(IdRequest(id: groupId));
+
+      if (!quiet) closeLoading();
+
+      connection.onGroupLoaded(Group.fromJson(response.data));
+    } catch (e) {
+      handleError(e, () => loadGroup(groupId, quiet: quiet),
+          () => dismissError(), "Retry");
+    }
+  }
+
+  void logProgress(ObjectiveProgressRequest request, String summary) async {
+    if (!await hasNetwork(() => logProgress(request, summary))) return;
+
+    showLoading("Logging");
+
+    try {
+      final response = await getDataManager().logObjectiveProgress(request);
+
+      closeLoading();
+
+      connection.onProgressLogged(Group.fromJson(response.data), summary);
+    } catch (e) {
+      handleError(e, () => logProgress(request, summary),
+          () => dismissError(), "Retry");
+    }
+  }
+
+  void nudge(NudgeRequest request, String who) async {
+    if (!await hasNetwork(() => nudge(request, who))) return;
+
+    try {
+      await getDataManager().nudgeGroupMember(request);
+
+      connection.onNudged(who);
+    } catch (e) {
+      handleError(e, () => nudge(request, who), () => dismissError(), "Retry");
+    }
+  }
+
+  void leave(String groupId) async {
+    if (!await hasNetwork(() => leave(groupId))) return;
+
+    showLoading("Leaving");
+
+    try {
+      await getDataManager().leaveGroupEntry(IdRequest(id: groupId));
+
+      closeLoading();
+
+      connection.onLeft();
+    } catch (e) {
+      handleError(e, () => leave(groupId), () => dismissError(), "Retry");
+    }
+  }
+}
diff --git a/frontend/lib/Grounded/see/group/ViewGroupEditor.dart b/frontend/lib/Grounded/see/group/ViewGroupEditor.dart
new file mode 100644
index 0000000..744b36e
--- /dev/null
+++ b/frontend/lib/Grounded/see/group/ViewGroupEditor.dart
@@ -0,0 +1,43 @@
+import '../../about/external/data/Group.dart';
+import '../../about/external/initial/GroupRequest.dart';
+import '../../about/external/initial/JoinGroupRequest.dart';
+import '../parent/ParentViewModel.dart';
+import 'ConnectGroupEditor.dart';
+
+class ViewGroupEditor extends ParentViewModel {
+  ConnectGroupEditor connection;
+
+  ViewGroupEditor(super.context, this.connection);
+
+  void create(GroupRequest request) async {
+    if (!await hasNetwork(() => create(request))) return;
+
+    showLoading("Creating the group");
+
+    try {
+      final response = await getDataManager().saveGroupEntry(request);
+
+      closeLoading();
+
+      connection.onGroupReady(Group.fromJson(response.data));
+    } catch (e) {
+      handleError(e, () => create(request), () => dismissError(), "Retry");
+    }
+  }
+
+  void join(JoinGroupRequest request) async {
+    if (!await hasNetwork(() => join(request))) return;
+
+    showLoading("Joining");
+
+    try {
+      final response = await getDataManager().joinGroupEntry(request);
+
+      closeLoading();
+
+      connection.onGroupReady(Group.fromJson(response.data));
+    } catch (e) {
+      handleError(e, () => join(request), () => dismissError(), "Retry");
+    }
+  }
+}
diff --git a/frontend/lib/Grounded/see/group/ViewGroupGoalEditor.dart b/frontend/lib/Grounded/see/group/ViewGroupGoalEditor.dart
new file mode 100644
index 0000000..9a90af1
--- /dev/null
+++ b/frontend/lib/Grounded/see/group/ViewGroupGoalEditor.dart
@@ -0,0 +1,25 @@
+import '../../about/external/initial/GroupGoalRequest.dart';
+import '../parent/ParentViewModel.dart';
+import 'ConnectGroupGoalEditor.dart';
+
+class ViewGroupGoalEditor extends ParentViewModel {
+  ConnectGroupGoalEditor connection;
+
+  ViewGroupGoalEditor(super.context, this.connection);
+
+  void save(GroupGoalRequest request) async {
+    if (!await hasNetwork(() => save(request))) return;
+
+    showLoading("Saving the shared goal");
+
+    try {
+      await getDataManager().saveGroupGoalEntry(request);
+
+      closeLoading();
+
+      connection.onGoalSaved();
+    } catch (e) {
+      handleError(e, () => save(request), () => dismissError(), "Retry");
+    }
+  }
+}
diff --git a/frontend/lib/Grounded/see/group/ViewGroups.dart b/frontend/lib/Grounded/see/group/ViewGroups.dart
new file mode 100644
index 0000000..e63af89
--- /dev/null
+++ b/frontend/lib/Grounded/see/group/ViewGroups.dart
@@ -0,0 +1,34 @@
+import '../../about/external/data/pages/request/HistoryRequest.dart';
+import '../../about/external/data/pages/request/PageAndSort.dart';
+import '../../about/external/data/pages/request/Pageable.dart';
+import '../../about/external/data/pages/request/Sort.dart';
+import '../../utils/ObjectConvertors.dart';
+import '../parent/ParentViewModel.dart';
+import 'ConnectGroups.dart';
+
+class ViewGroups extends ParentViewModel {
+  ConnectGroups connection;
+
+  ViewGroups(super.context, this.connection);
+
+  void loadGroups() async {
+    if (!await hasNetwork(() => loadGroups())) return;
+
+    showLoading("Loading your groups");
+
+    try {
+      final response = await getDataManager().getMyGroups(HistoryRequest(
+        query: PageAndSort(
+          sort: Sort('desc', 'lastMessageAt'),
+          page: Pageable(0, 0, 50, 0),
+        ),
+      ));
+
+      closeLoading();
+
+      connection.onGroupsLoaded(getGroupList(response.data));
+    } catch (e) {
+      handleError(e, () => loadGroups(), () => dismissError(), "Retry");
+    }
+  }
+}
diff --git a/frontend/lib/Grounded/see/home/ConnectHome.dart b/frontend/lib/Grounded/see/home/ConnectHome.dart
index 9134f57..6b35653 100644
--- a/frontend/lib/Grounded/see/home/ConnectHome.dart
+++ b/frontend/lib/Grounded/see/home/ConnectHome.dart
@@ -1,5 +1,6 @@
 import '../../about/external/data/Commitment.dart';
 import '../../about/external/data/ExcuseCluster.dart';
+import '../../about/external/data/Group.dart';
 import '../../about/external/data/ReportCard.dart';
 import '../../about/external/data/RoutineChain.dart';
 import '../../about/internal/application/Standing.dart';
@@ -20,8 +21,8 @@ abstract class ConnectHome {
   /// view. Null when it could not be loaded.
   void onWeekLoaded(ReportCard? week);
 
-  /// Water drunk today, in ml.
-  void onWaterLoaded(int ml);
+  /// Your groups, for the rail on Home.
+  void onGroupsLoaded(List<Group> groups);
 
   /// The quick to-do list, read from the device.
   void onTodosLoaded(List<TodoItem> todos);
diff --git a/frontend/lib/Grounded/see/home/HomeState.dart b/frontend/lib/Grounded/see/home/HomeState.dart
index 92bb617..2de0ac1 100644
--- a/frontend/lib/Grounded/see/home/HomeState.dart
+++ b/frontend/lib/Grounded/see/home/HomeState.dart
@@ -8,6 +8,7 @@ import 'package:stacked/stacked.dart';
 
 import '../../about/external/data/Commitment.dart';
 import '../../about/external/data/ExcuseCluster.dart';
+import '../../about/external/data/Group.dart';
 import '../../about/external/data/ReportCard.dart';
 import '../../about/external/data/RoutineChain.dart';
 import '../../about/internal/application/CommitmentClass.dart';
@@ -25,6 +26,7 @@ import '../../designs/Checkbox.dart';
 import '../../designs/Component.dart';
 import '../../designs/FloatingNav.dart';
 import '../../designs/GlassSurface.dart';
+import '../../designs/MemberAvatar.dart';
 import '../../designs/ProgressRing.dart';
 import '../../designs/Responsive.dart';
 import '../../designs/Shell.dart';
@@ -40,6 +42,9 @@ import '../../utils/ToneEngine.dart';
 import '../commitment/NewCommitment.dart';
 import '../excuse/ExcuseReport.dart';
 import '../goal/Goals.dart';
+import '../group/GroupChat.dart';
+import '../group/GroupEditor.dart';
+import '../group/Groups.dart';
 import '../overdue/OverdueQueue.dart';
 import '../reportcard/ReportCardScreen.dart';
 import '../routine/RoutineRunner.dart';
@@ -63,6 +68,8 @@ class HomeState extends State<Home> implements ConnectHome {
 
   List<TodoItem> _todos = <TodoItem>[];
 
+  List<Group> _groups = <Group>[];
+
   final TextEditingController _todoInput = TextEditingController();
 
   final FocusNode _todoFocus = FocusNode();
@@ -73,11 +80,6 @@ class HomeState extends State<Home> implements ConnectHome {
 
   bool _weekly = false;
 
-  int _waterMl = 0;
-
-  static const int _waterTarget = 2000;
-
-  static const int _waterStep = 250;
 
   Standing _standing = Standing.Good;
 
@@ -194,6 +196,24 @@ class HomeState extends State<Home> implements ConnectHome {
     }
   }
 
+  void _onOpenGroups() async {
+    await GroundedNavigation().navigateToPageWithData(const Groups(), context);
+    _model?.loadGroups();
+  }
+
+  void _onOpenGroupChat(Group group) async {
+    await GroundedNavigation()
+        .navigateToPageWithData(GroupChat(group: group), context);
+    _model?.loadGroups();
+  }
+
+  void _onAddPickGroup() async {
+    _onCloseAddSheet();
+    await GroundedNavigation()
+        .navigateToPageWithData(const GroupEditor(), context);
+    _model?.loadGroups();
+  }
+
   void _onOpenTraining() {
     GroundedNavigation()
         .navigateToPage(NavigatorType.justOpen, const Training(), context);
@@ -249,20 +269,6 @@ class HomeState extends State<Home> implements ConnectHome {
     });
   }
 
-  void _onAddWater() {
-    _onSetWaterDrops((_waterMl ~/ _waterStep) + 1);
-  }
-
-  /// Tapping the last filled drop empties it again, so a mis-tap is undoable.
-  void _onSetWaterDrops(int drops) {
-    final int current = _waterMl ~/ _waterStep;
-    final int next = drops == current ? drops - 1 : drops;
-    setState(() {
-      _waterMl = (next * _waterStep).clamp(0, _waterTarget);
-    });
-    _model?.saveWater(_waterMl);
-  }
-
   void _onOpenAddSheet() {
     showGeneralDialog(
       context: context,
@@ -398,10 +404,6 @@ class HomeState extends State<Home> implements ConnectHome {
                         crossAxisAlignment: CrossAxisAlignment.stretch,
                         mainAxisSize: MainAxisSize.min,
                         children: [
-                          if (!_distressed) ...[
-                            _waterCard(),
-                            const SizedBox(height: 28),
-                          ],
                           if (_distressed)
                             _frosted(_distressBody())
                           else if (queueIsHome)
@@ -436,16 +438,16 @@ class HomeState extends State<Home> implements ConnectHome {
                       label: "Goals",
                       onTap: _onOpenGoals
                     ),
+                    (
+                      icon: CupertinoIcons.person_3_fill,
+                      label: "Groups",
+                      onTap: _onOpenGroups
+                    ),
                     (
                       icon: CupertinoIcons.chart_bar_alt_fill,
                       label: "Insights",
                       onTap: _onOpenReportCard
                     ),
-                    (
-                      icon: CupertinoIcons.flame_fill,
-                      label: "Training",
-                      onTap: _onOpenTraining
-                    ),
                   ],
                 ).animate().fadeIn(duration: 400.ms, delay: 250.ms).slideY(
                     begin: 0.4,
@@ -945,72 +947,6 @@ class HomeState extends State<Home> implements ConnectHome {
     );
   }
 
-  // ── Water ─────────────────────────────────────────────────────────────────
-
-  /// Water against the daily target, as drops you tap to fill.
-  Widget _waterCard() {
-    final int filled = (_waterMl / _waterStep).floor();
-
-    return GlassSurface(
-      tint: colorGlassStrong,
-      padding: const EdgeInsets.fromLTRB(20, 18, 16, 20),
-      child: Column(
-        crossAxisAlignment: CrossAxisAlignment.stretch,
-        mainAxisSize: MainAxisSize.min,
-        children: [
-          Row(
-            children: [
-              Expanded(
-                child: Column(
-                  crossAxisAlignment: CrossAxisAlignment.start,
-                  mainAxisSize: MainAxisSize.min,
-                  children: [
-                    text("Water", 15, TextType.Regular, color: colorInkSoft),
-                    const SizedBox(height: 4),
-                    Row(
-                      crossAxisAlignment: CrossAxisAlignment.baseline,
-                      textBaseline: TextBaseline.alphabetic,
-                      children: [
-                        text(_thousands(_waterMl), 34, TextType.Medium,
-                            color: colorInk, letterSpacing: -1),
-                        const SizedBox(width: 4),
-                        text("/${_thousands(_waterTarget)} ml", 16,
-                            TextType.Regular,
-                            color: colorInkSoft),
-                      ],
-                    ),
-                  ],
-                ),
-              ),
-              glassCircle(CupertinoIcons.add, _onAddWater, size: 52),
-            ],
-          ),
-          const SizedBox(height: 18),
-          Row(
-            mainAxisAlignment: MainAxisAlignment.spaceBetween,
-            children: [
-              for (int index = 0; index < _waterTarget ~/ _waterStep; index++)
-                GestureDetector(
-                  onTap: () => _onSetWaterDrops(index + 1),
-                  behavior: HitTestBehavior.opaque,
-                  child: AnimatedScale(
-                    duration: const Duration(milliseconds: 240),
-                    curve: Curves.easeOutBack,
-                    scale: index < filled ? 1 : 0.9,
-                    child: Icon(
-                      Icons.water_drop,
-                      size: 38,
-                      color: index < filled ? colorWater : colorWaterEmpty,
-                    ),
-                  ),
-                ),
-            ],
-          ),
-        ],
-      ),
-    );
-  }
-
   // ── Add sheet ─────────────────────────────────────────────────────────────
 
   /// Everything you can add, over the blurred day — a close button floating
@@ -1053,7 +989,7 @@ class HomeState extends State<Home> implements ConnectHome {
                   children: [
                     Center(
                       child: Container(
-                          width: 40, height: 4, color: colorWaterEmpty),
+                          width: 40, height: 4, color: colorGrabber),
                     ),
                     const SizedBox(height: 18),
                     text("Add to today", 24, TextType.Medium,
@@ -1078,12 +1014,16 @@ class HomeState extends State<Home> implements ConnectHome {
                     Row(
                       children: [
                         Expanded(
-                            child: _addWideTile(kindIcon(RoutineKind.MustDo),
-                                "Must-do chain", _onAddPickMustDo)),
+                            child: _addTile(kindIcon(RoutineKind.MustDo),
+                                "Must-do", _onAddPickMustDo)),
                         const SizedBox(width: 10),
                         Expanded(
-                            child: _addWideTile(CupertinoIcons.flag,
+                            child: _addTile(CupertinoIcons.flag,
                                 "Goal", _onAddPickGoal)),
+                        const SizedBox(width: 10),
+                        Expanded(
+                            child: _addTile(CupertinoIcons.person_3,
+                                "Group", _onAddPickGroup)),
                       ],
                     ),
                     const SizedBox(height: 10),
@@ -1275,6 +1215,13 @@ class HomeState extends State<Home> implements ConnectHome {
         const SizedBox(height: 28),
         _todoSection(),
         const SizedBox(height: 28),
+        if (_groups.isNotEmpty) ...[
+          sectionBreak("Your groups",
+              caption: _groupsCaption(),
+              trailing: _viewAll("All groups", _onOpenGroups)),
+          _groupRail(),
+          const SizedBox(height: 28),
+        ],
         if (_upNext.isNotEmpty) ...[
           sectionBreak("Up next",
               caption: "${_upNext.length} routines",
@@ -1354,8 +1301,8 @@ class HomeState extends State<Home> implements ConnectHome {
             () => _onOpenKind(RoutineKind.MustDo)),
         _category(goalScene(goalAccents[4]), CupertinoIcons.flag_fill,
             "Goals", 13, _onOpenGoals),
-        _category(goalScene(goalAccents[2]),
-            CupertinoIcons.chart_bar_alt_fill, "Report", 21, _onOpenReportCard),
+        _category(goalScene(goalAccents[2]), CupertinoIcons.flame_fill,
+            "Training", 21, _onOpenTraining),
       ],
     );
   }
@@ -1533,6 +1480,125 @@ class HomeState extends State<Home> implements ConnectHome {
     );
   }
 
+  String _groupsCaption() {
+    int unread = 0;
+    for (Group group in _groups) {
+      unread = unread + group.unread;
+    }
+    return unread == 0 ? "${_groups.length} groups" : "$unread new messages";
+  }
+
+  /// Each group as a tile: its banner, who is in it, and the latest line.
+  /// Tapping goes straight into the chat.
+  Widget _groupRail() {
+    return SizedBox(
+      height: 214,
+      child: ListView.separated(
+        scrollDirection: Axis.horizontal,
+        clipBehavior: Clip.none,
+        itemCount: _groups.length,
+        separatorBuilder: (context, index) => const SizedBox(width: 12),
+        itemBuilder: (context, index) => _groupTile(_groups[index]),
+      ),
+    );
+  }
+
+  Widget _groupTile(Group group) {
+    final Color accent = goalColor(group.colourHex);
+
+    return GestureDetector(
+      onTap: () => _onOpenGroupChat(group),
+      child: Container(
+        width: 250,
+        decoration: BoxDecoration(
+          color: colorWhite,
+          boxShadow: const [
+            BoxShadow(
+              color: Color(0x142A3A30),
+              blurRadius: 20,
+              offset: Offset(0, 8),
+            ),
+          ],
+        ),
+        child: Column(
+          crossAxisAlignment: CrossAxisAlignment.stretch,
+          children: [
+            SizedBox(
+              height: 96,
+              child: Stack(
+                fit: StackFit.expand,
+                children: [
+                  SceneArt(
+                    palette: goalScene(accent),
+                    seed: sceneSeed(group.name),
+                    figure: CupertinoIcons.person_3_fill,
+                    figureScale: 0.5,
+                    figureAlignment: const Alignment(0.75, 0),
+                    shade: true,
+                  ),
+                  Padding(
+                    padding: const EdgeInsets.all(12),
+                    child: Column(
+                      crossAxisAlignment: CrossAxisAlignment.start,
+                      children: [
+                        if (group.unread > 0)
+                          Container(
+                            padding: const EdgeInsets.symmetric(
+                                horizontal: 8, vertical: 4),
+                            color: colorLime,
+                            child: text("${group.unread} new", 10,
+                                TextType.Medium,
+                                color: colorNight),
+                          ),
+                        const Spacer(),
+                        text(group.name, 18, TextType.Medium,
+                            color: colorWhite,
+                            maxLines: 1,
+                            overflow: TextOverflow.ellipsis),
+                      ],
+                    ),
+                  ),
+                ],
+              ),
+            ),
+            Expanded(
+              child: Padding(
+                padding: const EdgeInsets.fromLTRB(12, 12, 12, 12),
+                child: Column(
+                  crossAxisAlignment: CrossAxisAlignment.start,
+                  children: [
+                    text(
+                      group.lastMessage.isEmpty
+                          ? "No messages yet"
+                          : "${group.lastAuthor}: ${group.lastMessage}",
+                      13,
+                      TextType.Regular,
+                      color: colorInk,
+                      maxLines: 2,
+                      overflow: TextOverflow.ellipsis,
+                      height: 1.4,
+                    ),
+                    const Spacer(),
+                    Row(
+                      children: [
+                        avatarStack(
+                            group.members.map((member) => member.name).toList(),
+                            26),
+                        const Spacer(),
+                        Icon(CupertinoIcons.chat_bubble_2_fill,
+                            size: 16, color: colorInkSoft),
+                      ],
+                    ),
+                  ],
+                ),
+              ),
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+
   /// The quick to-do list: things to remember that are not promises. No
   /// window, no debt. Open items first, done ones struck through below.
   Widget _todoSection() {
@@ -2078,9 +2144,9 @@ class HomeState extends State<Home> implements ConnectHome {
   }
 
   @override
-  void onWaterLoaded(int ml) {
+  void onGroupsLoaded(List<Group> groups) {
     setState(() {
-      _waterMl = ml;
+      _groups = groups;
     });
   }
 
diff --git a/frontend/lib/Grounded/see/home/ViewHome.dart b/frontend/lib/Grounded/see/home/ViewHome.dart
index 8e30556..7bb4c51 100644
--- a/frontend/lib/Grounded/see/home/ViewHome.dart
+++ b/frontend/lib/Grounded/see/home/ViewHome.dart
@@ -1,5 +1,6 @@
 import '../../about/external/data/Commitment.dart';
 import '../../about/external/data/ExcuseCluster.dart';
+import '../../about/external/data/Group.dart';
 import '../../about/external/data/ReportCard.dart';
 import '../../about/external/data/RoutineChain.dart';
 import '../../about/external/data/pages/request/CommitmentsRequest.dart';
@@ -35,10 +36,10 @@ class ViewHome extends ParentViewModel {
 
     loadTodos();
 
-    loadWater();
-
     loadWeek();
 
+    loadGroups();
+
     loadPlan();
   }
 
@@ -61,12 +62,20 @@ class ViewHome extends ParentViewModel {
     }
   }
 
-  void loadWater() async {
-    connection.onWaterLoaded(await getDataManager().getWaterToday());
-  }
+  /// The groups rail. Quiet on failure: the rail just stays hidden.
+  void loadGroups() async {
+    try {
+      final response = await getDataManager().getMyGroups(HistoryRequest(
+        query: PageAndSort(
+          sort: Sort('desc', 'lastMessageAt'),
+          page: Pageable(0, 0, 20, 0),
+        ),
+      ));
 
-  void saveWater(int ml) async {
-    await getDataManager().setWaterToday(ml);
+      connection.onGroupsLoaded(getGroupList(response.data));
+    } catch (e) {
+      connection.onGroupsLoaded(<Group>[]);
+    }
   }
 
   void loadTodos() async {
diff --git a/frontend/lib/Grounded/utils/Colors.dart b/frontend/lib/Grounded/utils/Colors.dart
index 868b4f6..01e1fce 100644
--- a/frontend/lib/Grounded/utils/Colors.dart
+++ b/frontend/lib/Grounded/utils/Colors.dart
@@ -138,9 +138,8 @@ const Color colorHeaderSelected = Color(0xFF3D6B53);
 const Color colorBarNonNegotiable = Color(0xFFE8735A);
 const Color colorBarStandard = Color(0xFFF2C14E);
 const Color colorBarElective = Color(0xFF6FD39B);
-// Water: filled drops and the empty ones.
-const Color colorWater = Color(0xFF6E8EF0);
-const Color colorWaterEmpty = Color(0xFFDDE1DE);
+// The drag handle on white sheets.
+const Color colorGrabber = Color(0xFFDDE1DE);
 
 // ── Scene art ─────────────────────────────────────────────────────────────────
 // The painted landscapes that stand in for photography on cards. Each kind has
diff --git a/frontend/lib/Grounded/utils/CommonUtils.dart b/frontend/lib/Grounded/utils/CommonUtils.dart
index 14a45ac..299b939 100644
--- a/frontend/lib/Grounded/utils/CommonUtils.dart
+++ b/frontend/lib/Grounded/utils/CommonUtils.dart
@@ -404,3 +404,20 @@ int sceneSeed(String key) {
   }
   return hash;
 }
+
+/// An amount the way a person reads it: whole numbers with thousands
+/// separators, anything else to one decimal place.
+String formatAmount(double value) {
+  if (value == value.roundToDouble()) {
+    final String digits = value.round().abs().toString();
+    final StringBuffer out = StringBuffer(value < 0 ? "-" : "");
+    for (int index = 0; index < digits.length; index++) {
+      if (index > 0 && (digits.length - index) % 3 == 0) {
+        out.write(",");
+      }
+      out.write(digits[index]);
+    }
+    return out.toString();
+  }
+  return value.toStringAsFixed(1);
+}
diff --git a/frontend/lib/Grounded/utils/ObjectConvertors.dart b/frontend/lib/Grounded/utils/ObjectConvertors.dart
index f339854..186e3fd 100644
--- a/frontend/lib/Grounded/utils/ObjectConvertors.dart
+++ b/frontend/lib/Grounded/utils/ObjectConvertors.dart
@@ -4,6 +4,11 @@ import '../about/external/data/DebtEntry.dart';
 import '../about/external/data/ExcuseCluster.dart';
 import '../about/external/data/ExercisePrescription.dart';
 import '../about/external/data/Goal.dart';
+import '../about/external/data/Group.dart';
+import '../about/external/data/GroupGoal.dart';
+import '../about/external/data/GroupMember.dart';
+import '../about/external/data/GroupMessage.dart';
+import '../about/external/data/GroupObjective.dart';
 import '../about/external/data/Habit.dart';
 import '../about/external/data/Program.dart';
 import '../about/external/data/RoutineChain.dart';
@@ -122,3 +127,38 @@ List<String> getStringList(dynamic data) {
   }
   return (data as List).map((item) => item.toString()).toList();
 }
+
+List<Group> getGroupList(dynamic data) {
+  if (data == null) {
+    return <Group>[];
+  }
+  return (data as List).map((item) => Group.fromJson(item)).toList();
+}
+
+List<GroupMember> getGroupMemberList(dynamic data) {
+  if (data == null) {
+    return <GroupMember>[];
+  }
+  return (data as List).map((item) => GroupMember.fromJson(item)).toList();
+}
+
+List<GroupGoal> getGroupGoalList(dynamic data) {
+  if (data == null) {
+    return <GroupGoal>[];
+  }
+  return (data as List).map((item) => GroupGoal.fromJson(item)).toList();
+}
+
+List<GroupObjective> getGroupObjectiveList(dynamic data) {
+  if (data == null) {
+    return <GroupObjective>[];
+  }
+  return (data as List).map((item) => GroupObjective.fromJson(item)).toList();
+}
+
+List<GroupMessage> getGroupMessageList(dynamic data) {
+  if (data == null) {
+    return <GroupMessage>[];
+  }
+  return (data as List).map((item) => GroupMessage.fromJson(item)).toList();
+}
diff --git a/frontend/lib/main.dart b/frontend/lib/main.dart
index 9561b33..39537c7 100644
--- a/frontend/lib/main.dart
+++ b/frontend/lib/main.dart
@@ -51,6 +51,10 @@ class GroundedApp extends StatelessWidget {
             borderRadius: BorderRadius.zero,
           ),
         ),
+        // Material 3 rounds sheet tops by default; the app is square.
+        bottomSheetTheme: const BottomSheetThemeData(
+          shape: RoundedRectangleBorder(borderRadius: BorderRadius.zero),
+        ),
       ),
       home: const Splash(),
     );