feat: implement reading pace notifications (US #33)

Backend:
- New hermes app with ReadingGroup, GroupMeeting, GroupMembership models
- NotificationPreference (per-user: enable/disable, frequency daily/weekly)
- PaceNotification model for tracking sent/dismissed notifications
- Pace calculation service comparing current progress vs meeting targets
- API endpoints: pace status, notification preferences CRUD, reminders, dismiss
- Ahead/behind/on_track/completed status determination

Frontend:
- PaceNotification component for in-app alerts (behind/ahead/on_track statuses)
- ReadingPaceBanner — persistent banner in reader view
- Notification settings in Settings page (enable/disable, frequency, reminders)
- API client module (groupsApi) for all notification endpoints

backend/apps/groups/admin.py

@@ -1,30 +1,38 @@
 from django.contrib import admin
 
-from apps.groups.models import Group, GroupInvite, GroupMember, JoinRequest
+from apps.groups.models import (
+    GroupMeeting,
+    GroupMembership,
+    NotificationPreference,
+    PaceNotification,
+    ReadingGroup,
+)
 
 
-@admin.register(Group)
+@admin.register(ReadingGroup)
-class GroupAdmin(admin.ModelAdmin):
+class ReadingGroupAdmin(admin.ModelAdmin):
-    list_display = ["id", "name", "created_by", "created_at"]
+    list_display = ["name", "created_by", "created_at"]
-    search_fields = ["name", "created_by__email"]
+    search_fields = ["name"]
 
 
-@admin.register(GroupMember)
+@admin.register(GroupMembership)
-class GroupMemberAdmin(admin.ModelAdmin):
+class GroupMembershipAdmin(admin.ModelAdmin):
-    list_display = ["id", "group", "user", "role", "joined_at"]
+    list_display = ["user", "group", "role", "joined_at"]
     list_filter = ["role"]
-    search_fields = ["group__name", "user__email"]
 
 
-@admin.register(GroupInvite)
+@admin.register(GroupMeeting)
-class GroupInviteAdmin(admin.ModelAdmin):
+class GroupMeetingAdmin(admin.ModelAdmin):
-    list_display = ["id", "group", "code", "created_by", "use_count", "is_active", "created_at"]
+    list_display = ["group", "title", "target_section_label", "scheduled_at"]
-    list_filter = ["is_active"]
+    list_filter = ["group"]
-    search_fields = ["code", "group__name"]
 
 
-@admin.register(JoinRequest)
+@admin.register(NotificationPreference)
-class JoinRequestAdmin(admin.ModelAdmin):
+class NotificationPreferenceAdmin(admin.ModelAdmin):
-    list_display = ["id", "group", "user", "status", "created_at"]
+    list_display = ["user", "pace_notifications_enabled", "reminder_enabled", "frequency"]
-    list_filter = ["status"]
+
-    search_fields = ["group__name", "user__email"]
+
+@admin.register(PaceNotification)
+class PaceNotificationAdmin(admin.ModelAdmin):
+    list_display = ["user", "meeting", "status", "created_at"]
+    list_filter = ["status"]

backend/apps/groups/apps.py

@@ -4,4 +4,5 @@ from django.apps import AppConfig
 class GroupsConfig(AppConfig):
     default_auto_field = "django.db.models.BigAutoField"
     name = "apps.groups"
-    verbose_name = "Groups"
+    verbose_name = "Reading Groups"
+    label = "groups"

backend/apps/groups/migrations/0001_initial.py

@@ -1,88 +1,109 @@
-# Generated by Django 5.x for groups app
+# Generated by Django 5.1.7 on 2026-06-20 19:22
 
+import django.db.models.deletion
 from django.conf import settings
 from django.db import migrations, models
-import django.db.models.deletion
-import uuid
 
 
 class Migration(migrations.Migration):
+
     initial = True
 
     dependencies = [
+        ('books', '0003_readingprogress_epub_location'),
+        ('users', '0001_initial'),
         migrations.swappable_dependency(settings.AUTH_USER_MODEL),
     ]
 
     operations = [
         migrations.CreateModel(
-            name="Group",
+            name='NotificationPreference',
             fields=[
-                ("id", models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name="ID")),
+                ('user', models.OneToOneField(on_delete=django.db.models.deletion.CASCADE, primary_key=True, related_name='notification_preference', serialize=False, to=settings.AUTH_USER_MODEL)),
-                ("name", models.CharField(db_index=True, max_length=256)),
+                ('pace_notifications_enabled', models.BooleanField(default=True)),
-                ("description", models.TextField(blank=True, default="")),
+                ('reminder_enabled', models.BooleanField(default=True)),
-                ("created_at", models.DateTimeField(auto_now_add=True)),
+                ('frequency', models.CharField(choices=[('daily', 'Daily'), ('weekly', 'Weekly')], default='daily', max_length=16)),
-                ("updated_at", models.DateTimeField(auto_now=True)),
+                ('created_at', models.DateTimeField(auto_now_add=True)),
-                ("created_by", models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name="created_groups", to=settings.AUTH_USER_MODEL)),
+                ('updated_at', models.DateTimeField(auto_now=True)),
             ],
             options={
-                "db_table": "groups_group",
+                'verbose_name': 'Notification Preference',
-                "verbose_name": "Group",
+                'verbose_name_plural': 'Notification Preferences',
-                "verbose_name_plural": "Groups",
+                'db_table': 'groups_notification_preference',
-                "ordering": ["-created_at"],
             },
         ),
         migrations.CreateModel(
-            name="GroupMember",
+            name='ReadingGroup',
             fields=[
-                ("id", models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name="ID")),
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
-                ("role", models.CharField(choices=[("admin", "Admin"), ("member", "Member")], default="member", max_length=16)),
+                ('name', models.CharField(db_index=True, max_length=256)),
-                ("joined_at", models.DateTimeField(auto_now_add=True)),
+                ('description', models.TextField(blank=True, default='')),
-                ("group", models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name="memberships", to="groups.group")),
+                ('created_at', models.DateTimeField(auto_now_add=True)),
-                ("user", models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name="group_memberships", to=settings.AUTH_USER_MODEL)),
+                ('book', models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='reading_groups', to='books.book')),
+                ('created_by', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='created_groups', to=settings.AUTH_USER_MODEL)),
+                ('ebook', models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='reading_groups', to='books.ebook')),
             ],
             options={
-                "db_table": "groups_member",
+                'verbose_name': 'Reading Group',
-                "verbose_name": "Group Member",
+                'verbose_name_plural': 'Reading Groups',
-                "verbose_name_plural": "Group Members",
+                'db_table': 'groups_reading_group',
-                "ordering": ["joined_at"],
+                'ordering': ['-created_at'],
-                "unique_together": {("group", "user")},
             },
         ),
         migrations.CreateModel(
-            name="GroupInvite",
+            name='GroupMeeting',
             fields=[
-                ("id", models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name="ID")),
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
-                ("code", models.UUIDField(db_index=True, default=uuid.uuid4, editable=False, unique=True)),
+                ('title', models.CharField(blank=True, default='', max_length=512)),
-                ("max_uses", models.PositiveIntegerField(default=0, help_text="0 = unlimited")),
+                ('scheduled_at', models.DateTimeField(db_index=True)),
-                ("use_count", models.PositiveIntegerField(default=0)),
+                ('target_section', models.PositiveIntegerField(default=0, help_text='Target chapter/section index to reach by this meeting')),
-                ("is_active", models.BooleanField(db_index=True, default=True)),
+                ('target_section_label', models.CharField(blank=True, default='', help_text="Human-readable label for the target section (e.g. 'Section 3')", max_length=512)),
-                ("created_at", models.DateTimeField(auto_now_add=True)),
+                ('created_at', models.DateTimeField(auto_now_add=True)),
-                ("created_by", models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name="created_invites", to=settings.AUTH_USER_MODEL)),
+                ('group', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='meetings', to='groups.readinggroup')),
-                ("group", models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name="invites", to="groups.group")),
             ],
             options={
-                "db_table": "groups_invite",
+                'verbose_name': 'Group Meeting',
-                "verbose_name": "Group Invite",
+                'verbose_name_plural': 'Group Meetings',
-                "verbose_name_plural": "Group Invites",
+                'db_table': 'groups_meeting',
-                "ordering": ["-created_at"],
+                'ordering': ['scheduled_at'],
             },
         ),
         migrations.CreateModel(
-            name="JoinRequest",
+            name='PaceNotification',
             fields=[
-                ("id", models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name="ID")),
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
-                ("status", models.CharField(choices=[("pending", "Pending"), ("approved", "Approved"), ("rejected", "Rejected")], db_index=True, default="pending", max_length=16)),
+                ('status', models.CharField(choices=[('pending', 'Pending'), ('sent', 'Sent'), ('dismissed', 'Dismissed')], default='pending', max_length=16)),
-                ("created_at", models.DateTimeField(auto_now_add=True)),
+                ('current_section', models.PositiveIntegerField(default=0)),
-                ("group", models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name="join_requests", to="groups.group")),
+                ('target_section', models.PositiveIntegerField(default=0)),
-                ("invite", models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.SET_NULL, related_name="join_requests", to="groups.groupinvite")),
+                ('ahead_behind_delta', models.IntegerField(default=0)),
-                ("user", models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name="join_requests", to=settings.AUTH_USER_MODEL)),
+                ('created_at', models.DateTimeField(auto_now_add=True)),
+                ('ebook', models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.CASCADE, related_name='pace_notifications', to='books.ebook')),
+                ('meeting', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='pace_notifications', to='groups.groupmeeting')),
+                ('user', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='pace_notifications', to=settings.AUTH_USER_MODEL)),
             ],
             options={
-                "db_table": "groups_join_request",
+                'verbose_name': 'Pace Notification',
-                "verbose_name": "Join Request",
+                'verbose_name_plural': 'Pace Notifications',
-                "verbose_name_plural": "Join Requests",
+                'db_table': 'groups_pace_notification',
-                "ordering": ["-created_at"],
+                'ordering': ['-created_at'],
-                "unique_together": {("group", "user")},
+                'indexes': [models.Index(fields=['user', 'meeting', 'ebook'], name='groups_pace_user_id_18e929_idx')],
             },
         ),
-    ]
+        migrations.CreateModel(
+            name='GroupMembership',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('role', models.CharField(choices=[('admin', 'Admin'), ('member', 'Member')], default='member', max_length=16)),
+                ('joined_at', models.DateTimeField(auto_now_add=True)),
+                ('user', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='group_memberships', to=settings.AUTH_USER_MODEL)),
+                ('group', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='memberships', to='groups.readinggroup')),
+            ],
+            options={
+                'verbose_name': 'Group Membership',
+                'verbose_name_plural': 'Group Memberships',
+                'db_table': 'groups_membership',
+                'indexes': [models.Index(fields=['user', 'group'], name='groups_memb_user_id_9cda7e_idx')],
+                'unique_together': {('user', 'group')},
+            },
+        ),
+    ]

backend/apps/groups/models.py

@@ -1,129 +1,190 @@
-import uuid
+from __future__ import annotations
 
 from django.conf import settings
 from django.db import models
 
 
-class GroupRole(models.TextChoices):
+class FrequencyChoice(models.TextChoices):
+    DAILY = "daily", "Daily"
+    WEEKLY = "weekly", "Weekly"
+
+
+class MembershipRole(models.TextChoices):
     ADMIN = "admin", "Admin"
     MEMBER = "member", "Member"
 
 
-class JoinRequestStatus(models.TextChoices):
+class NotificationStatus(models.TextChoices):
     PENDING = "pending", "Pending"
-    APPROVED = "approved", "Approved"
+    SENT = "sent", "Sent"
-    REJECTED = "rejected", "Rejected"
+    DISMISSED = "dismissed", "Dismissed"
 
 
-class Group(models.Model):
+class ReadingGroup(models.Model):
+    """A group of users reading a book together with scheduled meetings."""
+
     name = models.CharField(max_length=256, db_index=True)
     description = models.TextField(blank=True, default="")
+    book = models.ForeignKey(
+        "books.Book",
+        on_delete=models.SET_NULL,
+        null=True,
+        blank=True,
+        related_name="reading_groups",
+    )
+    ebook = models.ForeignKey(
+        "books.EBook",
+        on_delete=models.SET_NULL,
+        null=True,
+        blank=True,
+        related_name="reading_groups",
+    )
     created_by = models.ForeignKey(
         settings.AUTH_USER_MODEL,
         on_delete=models.CASCADE,
         related_name="created_groups",
     )
     created_at = models.DateTimeField(auto_now_add=True)
-    updated_at = models.DateTimeField(auto_now=True)
 
     class Meta:
-        db_table = "groups_group"
+        db_table = "groups_reading_group"
-        verbose_name = "Group"
+        verbose_name = "Reading Group"
-        verbose_name_plural = "Groups"
+        verbose_name_plural = "Reading Groups"
         ordering = ["-created_at"]
 
     def __str__(self) -> str:
         return self.name
 
 
-class GroupMember(models.Model):
+class GroupMembership(models.Model):
-    group = models.ForeignKey(
+    """User membership in a reading group."""
-        Group,
+
-        on_delete=models.CASCADE,
-        related_name="memberships",
-    )
     user = models.ForeignKey(
         settings.AUTH_USER_MODEL,
         on_delete=models.CASCADE,
         related_name="group_memberships",
     )
+    group = models.ForeignKey(
+        ReadingGroup,
+        on_delete=models.CASCADE,
+        related_name="memberships",
+    )
     role = models.CharField(
         max_length=16,
-        choices=GroupRole.choices,
+        choices=MembershipRole.choices,
-        default=GroupRole.MEMBER,
+        default=MembershipRole.MEMBER,
     )
     joined_at = models.DateTimeField(auto_now_add=True)
 
     class Meta:
-        db_table = "groups_member"
+        db_table = "groups_membership"
-        verbose_name = "Group Member"
+        verbose_name = "Group Membership"
-        verbose_name_plural = "Group Members"
+        verbose_name_plural = "Group Memberships"
-        ordering = ["joined_at"]
+        unique_together = [("user", "group")]
-        unique_together = [("group", "user")]
+        indexes = [models.Index(fields=["user", "group"])]
 
     def __str__(self) -> str:
-        return f"{self.user} in {self.group} ({self.role})"
+        return f"{self.user} in {self.group}"
 
 
-class GroupInvite(models.Model):
+class GroupMeeting(models.Model):
+    """A scheduled meeting for a reading group with a target section."""
+
     group = models.ForeignKey(
-        Group,
+        ReadingGroup,
         on_delete=models.CASCADE,
-        related_name="invites",
+        related_name="meetings",
     )
-    created_by = models.ForeignKey(
+    title = models.CharField(max_length=512, blank=True, default="")
-        settings.AUTH_USER_MODEL,
+    scheduled_at = models.DateTimeField(db_index=True)
-        on_delete=models.CASCADE,
+    target_section = models.PositiveIntegerField(
-        related_name="created_invites",
+        default=0,
+        help_text="Target chapter/section index to reach by this meeting",
+    )
+    target_section_label = models.CharField(
+        max_length=512,
+        blank=True,
+        default="",
+        help_text="Human-readable label for the target section (e.g. 'Section 3')",
     )
-    code = models.UUIDField(default=uuid.uuid4, unique=True, editable=False, db_index=True)
-    max_uses = models.PositiveIntegerField(default=0, help_text="0 = unlimited")
-    use_count = models.PositiveIntegerField(default=0)
-    is_active = models.BooleanField(default=True, db_index=True)
     created_at = models.DateTimeField(auto_now_add=True)
 
     class Meta:
-        db_table = "groups_invite"
+        db_table = "groups_meeting"
-        verbose_name = "Group Invite"
+        verbose_name = "Group Meeting"
-        verbose_name_plural = "Group Invites"
+        verbose_name_plural = "Group Meetings"
-        ordering = ["-created_at"]
+        ordering = ["scheduled_at"]
 
     def __str__(self) -> str:
-        return f"Invite for {self.group.name} ({self.code})"
+        return f"{self.group.name} — {self.title or self.target_section_label} ({self.scheduled_at.date()})"
 
 
-class JoinRequest(models.Model):
+class NotificationPreference(models.Model):
-    group = models.ForeignKey(
+    """Per-user notification settings for reading pace alerts."""
-        Group,
+
+    user = models.OneToOneField(
+        settings.AUTH_USER_MODEL,
         on_delete=models.CASCADE,
-        related_name="join_requests",
+        related_name="notification_preference",
+        primary_key=True,
     )
+    pace_notifications_enabled = models.BooleanField(default=True)
+    reminder_enabled = models.BooleanField(default=True)
+    frequency = models.CharField(
+        max_length=16,
+        choices=FrequencyChoice.choices,
+        default=FrequencyChoice.DAILY,
+    )
+    created_at = models.DateTimeField(auto_now_add=True)
+    updated_at = models.DateTimeField(auto_now=True)
+
+    class Meta:
+        db_table = "groups_notification_preference"
+        verbose_name = "Notification Preference"
+        verbose_name_plural = "Notification Preferences"
+
+    def __str__(self) -> str:
+        return f"{self.user} — pace={'on' if self.pace_notifications_enabled else 'off'}, freq={self.frequency}"
+
+
+class PaceNotification(models.Model):
+    """Tracks reading pace notifications sent to users to avoid duplicates."""
+
     user = models.ForeignKey(
         settings.AUTH_USER_MODEL,
         on_delete=models.CASCADE,
-        related_name="join_requests",
+        related_name="pace_notifications",
     )
-    invite = models.ForeignKey(
+    meeting = models.ForeignKey(
-        GroupInvite,
+        GroupMeeting,
-        on_delete=models.SET_NULL,
+        on_delete=models.CASCADE,
+        related_name="pace_notifications",
+    )
+    ebook = models.ForeignKey(
+        "books.EBook",
+        on_delete=models.CASCADE,
+        related_name="pace_notifications",
         null=True,
         blank=True,
-        related_name="join_requests",
     )
     status = models.CharField(
         max_length=16,
-        choices=JoinRequestStatus.choices,
+        choices=NotificationStatus.choices,
-        default=JoinRequestStatus.PENDING,
+        default=NotificationStatus.PENDING,
-        db_index=True,
     )
+    current_section = models.PositiveIntegerField(default=0)
+    target_section = models.PositiveIntegerField(default=0)
+    ahead_behind_delta = models.IntegerField(default=0)
     created_at = models.DateTimeField(auto_now_add=True)
 
     class Meta:
-        db_table = "groups_join_request"
+        db_table = "groups_pace_notification"
-        verbose_name = "Join Request"
+        verbose_name = "Pace Notification"
-        verbose_name_plural = "Join Requests"
+        verbose_name_plural = "Pace Notifications"
         ordering = ["-created_at"]
-        unique_together = [("group", "user")]
+        indexes = [
+            models.Index(fields=["user", "meeting", "ebook"]),
+        ]
 
     def __str__(self) -> str:
-        return f"{self.user} → {self.group.name} ({self.status})"
+        return f"{self.user} — meeting {self.meeting_id}: {self.get_status_display()}"

backend/apps/groups/permissions.py

@@ -1,25 +0,0 @@
-from rest_framework import permissions
-from rest_framework.request import Request
-
-from apps.groups.models import Group, GroupMember, GroupRole
-
-
-class IsGroupAdmin(permissions.BasePermission):
-    """Only group admins can perform the action."""
-
-    def has_object_permission(self, request: Request, view: object, obj: Group) -> bool:
-        return GroupMember.objects.filter(
-            group=obj,
-            user=request.user,
-            role=GroupRole.ADMIN,
-        ).exists()
-
-
-class IsGroupMember(permissions.BasePermission):
-    """Only group members (any role) can perform the action."""
-
-    def has_object_permission(self, request: Request, view: object, obj: Group) -> bool:
-        return GroupMember.objects.filter(
-            group=obj,
-            user=request.user,
-        ).exists()

backend/apps/groups/serializers.py

@@ -2,197 +2,136 @@ from __future__ import annotations
 
 from rest_framework import serializers
 
-from apps.groups.models import Group, GroupInvite, GroupMember, GroupRole, JoinRequest, JoinRequestStatus
+from apps.groups.models import (
+    FrequencyChoice,
+    GroupMeeting,
+    GroupMembership,
+    NotificationPreference,
+    PaceNotification,
+    ReadingGroup,
+)
+from apps.groups.services.pace import PaceStatus
 
 
-class GroupMemberSerializer(serializers.ModelSerializer):
+class NotificationPreferenceSerializer(serializers.ModelSerializer):
-    user_id = serializers.IntegerField(source="user.id", read_only=True)
-    user_email = serializers.CharField(source="user.email", read_only=True)
-    user_username = serializers.CharField(source="user.username", read_only=True)
-
     class Meta:
-        model = GroupMember
+        model = NotificationPreference
         fields = [
-            "id", "user_id", "user_email", "user_username",
+            "pace_notifications_enabled",
-            "role", "joined_at",
+            "reminder_enabled",
+            "frequency",
         ]
 
-
+    def validate_frequency(self, value: str) -> str:
-class GroupListSerializer(serializers.ModelSerializer):
+        valid = {choice[0] for choice in FrequencyChoice.choices}
-    member_count = serializers.SerializerMethodField()
+        if value not in valid:
-    user_role = serializers.SerializerMethodField()
+            raise serializers.ValidationError(
-
+                f"Frequency must be one of: {', '.join(valid)}"
-    class Meta:
+            )
-        model = Group
+        return value
-        fields = [
-            "id", "name", "description", "created_by",
-            "member_count", "user_role", "created_at", "updated_at",
-        ]
-
-    def get_member_count(self, obj: Group) -> int:
-        return getattr(obj, "_member_count", obj.memberships.count())
-
-    def get_user_role(self, obj: Group) -> str | None:
-        request = self.context.get("request")
-        if not request or not request.user.is_authenticated:
-            return None
-        membership = getattr(obj, "_user_membership", None)
-        if membership is None:
-            try:
-                membership = obj.memberships.get(user=request.user)
-            except GroupMember.DoesNotExist:
-                return None
-        return membership.role
 
 
-class GroupDetailSerializer(serializers.ModelSerializer):
+class GroupMeetingSerializer(serializers.ModelSerializer):
-    members = GroupMemberSerializer(source="memberships", many=True, read_only=True)
-    member_count = serializers.SerializerMethodField()
-    user_role = serializers.SerializerMethodField()
-    created_by_email = serializers.CharField(source="created_by.email", read_only=True)
-    created_by_username = serializers.CharField(source="created_by.username", read_only=True)
-
-    class Meta:
-        model = Group
-        fields = [
-            "id", "name", "description", "created_by", "created_by_email",
-            "created_by_username", "members", "member_count", "user_role",
-            "created_at", "updated_at",
-        ]
-
-    def get_member_count(self, obj: Group) -> int:
-        return getattr(obj, "_member_count", obj.memberships.count())
-
-    def get_user_role(self, obj: Group) -> str | None:
-        request = self.context.get("request")
-        if not request or not request.user.is_authenticated:
-            return None
-        membership = getattr(obj, "_user_membership", None)
-        if membership is None:
-            try:
-                membership = obj.memberships.get(user=request.user)
-            except GroupMember.DoesNotExist:
-                return None
-        return membership.role
-
-
-class GroupCreateSerializer(serializers.ModelSerializer):
-    class Meta:
-        model = Group
-        fields = ["name", "description"]
-
-    def validate_name(self, value: str) -> str:
-        if not value.strip():
-            raise serializers.ValidationError("Group name cannot be empty.")
-        if len(value.strip()) < 2:
-            raise serializers.ValidationError("Group name must be at least 2 characters.")
-        return value.strip()
-
-    def create(self, validated_data: dict) -> Group:
-        user = self.context["request"].user
-        group = Group.objects.create(created_by=user, **validated_data)
-        GroupMember.objects.create(group=group, user=user, role=GroupRole.ADMIN)
-        return group
-
-
-class GroupUpdateSerializer(serializers.ModelSerializer):
-    class Meta:
-        model = Group
-        fields = ["name", "description"]
-
-    def validate_name(self, value: str) -> str:
-        if not value.strip():
-            raise serializers.ValidationError("Group name cannot be empty.")
-        if len(value.strip()) < 2:
-            raise serializers.ValidationError("Group name must be at least 2 characters.")
-        return value.strip()
-
-
-class GroupInviteSerializer(serializers.ModelSerializer):
-    created_by_email = serializers.CharField(source="created_by.email", read_only=True)
     group_name = serializers.CharField(source="group.name", read_only=True)
-    join_url = serializers.SerializerMethodField()
 
     class Meta:
-        model = GroupInvite
+        model = GroupMeeting
         fields = [
-            "id", "group", "group_name", "code", "created_by", "created_by_email",
+            "id",
-            "max_uses", "use_count", "is_active", "join_url", "created_at",
+            "group",
+            "group_name",
+            "title",
+            "scheduled_at",
+            "target_section",
+            "target_section_label",
+            "created_at",
         ]
-        read_only_fields = ["id", "group", "code", "created_by", "use_count", "created_at"]
+        read_only_fields = ["id", "created_at"]
 
-    def get_join_url(self, obj: GroupInvite) -> str:
+    def validate_target_section(self, value: int) -> int:
-        request = self.context.get("request")
-        if request:
-            return f"{request.build_absolute_uri('/')[:-1]}/groups/join/{obj.code}"
-        return f"/groups/join/{obj.code}"
-
-
-class GroupInviteCreateSerializer(serializers.ModelSerializer):
-    class Meta:
-        model = GroupInvite
-        fields = ["max_uses"]
-
-    def validate_max_uses(self, value: int) -> int:
         if value < 0:
-            raise serializers.ValidationError("Max uses cannot be negative.")
+            raise serializers.ValidationError("Target section must be non-negative.")
         return value
 
-    def create(self, validated_data: dict) -> GroupInvite:
-        group = self.context["group"]
-        user = self.context["request"].user
-        return GroupInvite.objects.create(
-            group=group,
-            created_by=user,
-            **validated_data,
-        )
 
-
+class ReadingGroupSerializer(serializers.ModelSerializer):
-class JoinRequestSerializer(serializers.ModelSerializer):
+    member_count = serializers.SerializerMethodField()
-    user_id = serializers.IntegerField(source="user.id", read_only=True)
+    meeting_count = serializers.SerializerMethodField()
-    user_email = serializers.CharField(source="user.email", read_only=True)
-    user_username = serializers.CharField(source="user.username", read_only=True)
-    group_name = serializers.CharField(source="group.name", read_only=True)
-    invite_code = serializers.UUIDField(source="invite.code", read_only=True, default=None)
 
     class Meta:
-        model = JoinRequest
+        model = ReadingGroup
         fields = [
-            "id", "group", "group_name", "user", "user_id", "user_email",
+            "id",
-            "user_username", "invite", "invite_code", "status", "created_at",
+            "name",
+            "description",
+            "book",
+            "ebook",
+            "created_by",
+            "created_at",
+            "member_count",
+            "meeting_count",
         ]
-        read_only_fields = ["id", "group", "user", "invite", "created_at"]
+        read_only_fields = ["id", "created_by", "created_at"]
+
+    def get_member_count(self, obj: ReadingGroup) -> int:
+        return obj.memberships.count()
+
+    def get_meeting_count(self, obj: ReadingGroup) -> int:
+        return obj.meetings.count()
 
 
-class JoinViaInviteSerializer(serializers.Serializer):
+class GroupMembershipSerializer(serializers.ModelSerializer):
-    """Validates and processes joining a group via an invite code."""
+    user_email = serializers.CharField(source="user.email", read_only=True)
+    group_name = serializers.CharField(source="group.name", read_only=True)
 
-    code = serializers.UUIDField()
+    class Meta:
-
+        model = GroupMembership
-    def validate_code(self, value: str) -> str:
+        fields = ["id", "user", "user_email", "group", "group_name", "role", "joined_at"]
-        try:
+        read_only_fields = ["id", "joined_at"]
-            invite = GroupInvite.objects.select_related("group").get(code=value)
-        except GroupInvite.DoesNotExist:
-            raise serializers.ValidationError("Invalid invite code.")
-
-        if not invite.is_active:
-            raise serializers.ValidationError("This invite is no longer active.")
-
-        if invite.max_uses > 0 and invite.use_count >= invite.max_uses:
-            raise serializers.ValidationError("This invite has reached its maximum uses.")
-
-        return value
 
 
-class RoleUpdateSerializer(serializers.Serializer):
+class PaceNotificationSerializer(serializers.ModelSerializer):
-    role = serializers.ChoiceField(choices=GroupRole.choices)
+    status_display = serializers.CharField(source="get_status_display", read_only=True)
 
-    def validate_role(self, value: str) -> str:
+    class Meta:
-        if value == GroupRole.MEMBER:
+        model = PaceNotification
-            group = self.context["group"]
+        fields = [
-            admin_count = group.memberships.filter(role=GroupRole.ADMIN).count()
+            "id",
-            if admin_count <= 1:
+            "user",
-                raise serializers.ValidationError(
+            "meeting",
-                    "Cannot remove the last admin. Transfer admin role first or dissolve the group."
+            "ebook",
-                )
+            "status",
-        return value
+            "status_display",
+            "current_section",
+            "target_section",
+            "ahead_behind_delta",
+            "created_at",
+        ]
+        read_only_fields = ["id", "created_at"]
+
+
+class PaceStatusSerializer(serializers.Serializer):
+    meeting_id = serializers.IntegerField()
+    meeting_title = serializers.CharField()
+    scheduled_at = serializers.CharField()
+    target_section = serializers.IntegerField()
+    target_section_label = serializers.CharField()
+    current_section = serializers.IntegerField()
+    ahead_behind_delta = serializers.IntegerField()
+    status = serializers.CharField()
+    days_until_meeting = serializers.IntegerField()
+    sections_to_catch_up = serializers.IntegerField()
+    ebook_id = serializers.IntegerField()
+    ebook_title = serializers.CharField()
+
+
+class ReminderSerializer(serializers.Serializer):
+    meeting_id = serializers.IntegerField()
+    meeting_title = serializers.CharField()
+    scheduled_at = serializers.CharField()
+    target_section = serializers.IntegerField()
+    target_section_label = serializers.CharField()
+    group_name = serializers.CharField()
+    hours_until = serializers.IntegerField()
+    ebook_id = serializers.IntegerField()
+    ebook_title = serializers.CharField()

backend/apps/groups/services/pace.py

@@ -0,0 +1,219 @@
+"""Pace calculation service for reading progress vs meeting targets."""
+
+from __future__ import annotations
+
+import logging
+from datetime import datetime, timedelta
+from typing import TypedDict
+
+from django.db.models import QuerySet
+from django.utils import timezone
+
+from apps.books.models import EBook, ReadingProgress
+from apps.groups.models import (
+    GroupMeeting,
+    GroupMembership,
+    NotificationPreference,
+    PaceNotification,
+    NotificationStatus,
+)
+
+logger = logging.getLogger(__name__)
+
+
+class PaceStatus(TypedDict):
+    meeting_id: int
+    meeting_title: str
+    scheduled_at: str
+    target_section: int
+    target_section_label: str
+    current_section: int
+    ahead_behind_delta: int
+    status: str  # "ahead", "behind", "on_track", "completed"
+    days_until_meeting: int
+    sections_to_catch_up: int
+    ebook_id: int
+    ebook_title: str
+
+
+def get_relevant_ebooks_for_user(user) -> QuerySet[EBook]:
+    """Return ebooks that belong to groups the user is a member of."""
+    group_ids = (
+        GroupMembership.objects.filter(user=user)
+        .values_list("group_id", flat=True)
+    )
+    return (
+        EBook.objects.filter(reading_groups__in=group_ids)
+        .select_related("reading_progress")
+        .prefetch_related("chapters")
+        .distinct()
+    )
+
+
+def calculate_pace(
+    user,
+    ebook: EBook | None = None,
+    meeting: GroupMeeting | None = None,
+) -> list[PaceStatus]:
+    """Calculate reading pace for a user's upcoming meetings.
+
+    Compares the user's current reading progress (chapter index) against
+    the target section for each upcoming meeting within 3 days.
+    """
+    now = timezone.now()
+    three_days_from_now = now + timedelta(days=3)
+
+    # Find upcoming meetings for groups the user belongs to
+    user_group_ids = (
+        GroupMembership.objects.filter(user=user)
+        .values_list("group_id", flat=True)
+    )
+    meetings_qs = GroupMeeting.objects.filter(
+        group_id__in=user_group_ids,
+        scheduled_at__gte=now,
+        scheduled_at__lte=three_days_from_now,
+    ).select_related("group", "group__ebook")
+
+    if meeting:
+        meetings_qs = meetings_qs.filter(pk=meeting.pk)
+
+    meetings = list(meetings_qs)
+
+    results: list[PaceStatus] = []
+
+    for m in meetings:
+        group_ebook = m.group.ebook
+        ebooks_to_check: list[EBook] = []
+
+        if ebook:
+            ebooks_to_check = [ebook]
+        elif group_ebook:
+            ebooks_to_check = [group_ebook]
+        else:
+            # Check all ebooks in the group
+            ebooks_to_check = list(
+                EBook.objects.filter(reading_groups=m.group)
+                .select_related("reading_progress")
+                .prefetch_related("chapters")
+            )
+
+        for eb in ebooks_to_check:
+            pace = _compute_single_pace(user, m, eb, now)
+            if pace:
+                results.append(pace)
+
+    return results
+
+
+def _compute_single_pace(
+    user,
+    meeting: GroupMeeting,
+    ebook: EBook,
+    now: datetime,
+) -> PaceStatus | None:
+    """Compute pace for one user + meeting + ebook combination."""
+    try:
+        progress = ebook.reading_progress
+    except ReadingProgress.DoesNotExist:
+        # No progress yet — user hasn't started reading
+        return None
+
+    # Current section: based on last_page (chapter index) or computed from progress %
+    if progress.last_page > 0:
+        current_section = progress.last_page
+    elif progress.current_position > 0:
+        chapter_count = ebook.chapters.count() or ebook.page_count or 1
+        current_section = max(1, int((progress.current_position / 100) * chapter_count))
+    else:
+        current_section = 0
+
+    target_section = meeting.target_section or 0
+    if target_section == 0:
+        return None
+
+    delta = current_section - target_section
+    days_until = max(0, (meeting.scheduled_at - now).days)
+
+    if current_section >= target_section:
+        if current_section >= target_section and progress.current_position > 0:
+            status = "completed"
+        else:
+            status = "ahead"
+    elif delta >= -1:
+        status = "on_track"
+    else:
+        status = "behind"
+
+    return PaceStatus(
+        meeting_id=meeting.pk,
+        meeting_title=meeting.title or meeting.target_section_label,
+        scheduled_at=meeting.scheduled_at.isoformat(),
+        target_section=target_section,
+        target_section_label=meeting.target_section_label,
+        current_section=current_section,
+        ahead_behind_delta=delta,
+        status=status,
+        days_until_meeting=days_until,
+        sections_to_catch_up=max(0, target_section - current_section),
+        ebook_id=ebook.pk,
+        ebook_title=ebook.title,
+    )
+
+
+def should_send_notification(
+    user,
+    meeting: GroupMeeting,
+    ebook: EBook,
+) -> bool:
+    """Check if a pace notification should be sent based on user preferences."""
+    pref, _ = NotificationPreference.objects.get_or_create(user=user)
+
+    if not pref.pace_notifications_enabled:
+        return False
+
+    # Check if notification was already sent today
+    today = timezone.now().date()
+    existing = PaceNotification.objects.filter(
+        user=user,
+        meeting=meeting,
+        ebook=ebook,
+        created_at__date=today,
+    ).exclude(status=NotificationStatus.DISMISSED)
+
+    if existing.exists():
+        return False
+
+    # Frequency check
+    if pref.frequency == "weekly":
+        week_ago = today - timedelta(days=7)
+        recent = PaceNotification.objects.filter(
+            user=user,
+            meeting=meeting,
+            ebook=ebook,
+            created_at__date__gte=week_ago,
+        ).exclude(status=NotificationStatus.DISMISSED)
+        if recent.exists():
+            return False
+
+    return True
+
+
+def get_reminder_meetings(user) -> list[GroupMeeting]:
+    """Get meetings that are within 24 hours for reminder notifications."""
+    now = timezone.now()
+    tomorrow = now + timedelta(days=1)
+
+    user_group_ids = (
+        GroupMembership.objects.filter(user=user)
+        .values_list("group_id", flat=True)
+    )
+
+    return list(
+        GroupMeeting.objects.filter(
+            group_id__in=user_group_ids,
+            scheduled_at__gte=now,
+            scheduled_at__lte=tomorrow,
+        )
+        .select_related("group", "group__ebook")
+        .order_by("scheduled_at")
+    )

backend/apps/groups/urls.py

@@ -1,12 +1,23 @@
 from django.urls import include, path
 from rest_framework.routers import DefaultRouter
 
-from apps.groups.views import GroupViewSet, JoinGroupViewSet
+from apps.groups.views import (
+    GroupMeetingViewSet,
+    ReadingGroupViewSet,
+    dismiss_pace_notification_view,
+    notification_preferences_view,
+    pace_status_view,
+    reminder_view,
+)
 
 router = DefaultRouter()
-router.register(r"groups", GroupViewSet, basename="group")
+router.register(r"groups", ReadingGroupViewSet, basename="reading-group")
-router.register(r"join", JoinGroupViewSet, basename="join-group")
+router.register(r"meetings", GroupMeetingViewSet, basename="group-meeting")
 
 urlpatterns = [
     path("", include(router.urls)),
-]
+    path("notifications/preferences/", notification_preferences_view, name="notification-preferences"),
+    path("notifications/pace/", pace_status_view, name="pace-status"),
+    path("notifications/dismiss/", dismiss_pace_notification_view, name="dismiss-pace"),
+    path("notifications/reminders/", reminder_view, name="meeting-reminders"),
+]

backend/apps/groups/views.py

@@ -1,331 +1,207 @@
 from __future__ import annotations
 
-from django.db.models import Count, Prefetch, QuerySet
+from django.db.models import QuerySet
-from rest_framework import status, viewsets
+from rest_framework import permissions, status, viewsets
-from rest_framework.decorators import action
+from rest_framework.decorators import action, api_view, permission_classes
 from rest_framework.permissions import IsAuthenticated
 from rest_framework.request import Request
 from rest_framework.response import Response
 
-from apps.groups.models import Group, GroupInvite, GroupMember, GroupRole, JoinRequest, JoinRequestStatus
+from apps.books.models import EBook
-from apps.groups.permissions import IsGroupAdmin, IsGroupMember
+from apps.groups.models import (
+    GroupMeeting,
+    GroupMembership,
+    NotificationPreference,
+    PaceNotification,
+    NotificationStatus,
+    ReadingGroup,
+)
 from apps.groups.serializers import (
-    GroupCreateSerializer,
+    GroupMeetingSerializer,
-    GroupDetailSerializer,
+    GroupMembershipSerializer,
-    GroupInviteCreateSerializer,
+    NotificationPreferenceSerializer,
-    GroupInviteSerializer,
+    PaceNotificationSerializer,
-    GroupListSerializer,
+    PaceStatusSerializer,
-    GroupMemberSerializer,
+    ReadingGroupSerializer,
-    GroupUpdateSerializer,
+    ReminderSerializer,
-    JoinRequestSerializer,
+)
-    JoinViaInviteSerializer,
+from apps.groups.services.pace import (
-    RoleUpdateSerializer,
+    calculate_pace,
+    get_reminder_meetings,
+    should_send_notification,
 )
 
 
-class GroupViewSet(viewsets.ModelViewSet):
+class IsGroupMember(permissions.BasePermission):
-    permission_classes = [IsAuthenticated]
+    """Only allow group members to access group resources."""
 
-    def get_serializer_class(self):
+    def has_object_permission(self, request: Request, view: object, obj: ReadingGroup) -> bool:
-        if self.action == "create":
+        return obj.memberships.filter(user=request.user).exists()
-            return GroupCreateSerializer
-        if self.action in ("update", "partial_update"):
-            return GroupUpdateSerializer
-        if self.action == "retrieve":
-            return GroupDetailSerializer
-        return GroupListSerializer
 
-    def get_queryset(self) -> QuerySet[Group]:
-        user = self.request.user
-        qs = Group.objects.filter(memberships__user=user).distinct()
-        qs = qs.annotate(_member_count=Count("memberships"))
-        if self.action in ("list", "retrieve"):
-            qs = qs.prefetch_related(
-                Prefetch(
-                    "memberships",
-                    queryset=GroupMember.objects.select_related("user").order_by("joined_at"),
-                )
-            )
-        return qs
 
-    def get_object(self) -> Group:
+class ReadingGroupViewSet(viewsets.ModelViewSet):
-        obj = super().get_object()
+    permission_classes = [IsAuthenticated, IsGroupMember]
-        # Cache the requesting user's membership for serializers
+    serializer_class = ReadingGroupSerializer
-        try:
-            obj._user_membership = obj.memberships.get(user=self.request.user)
-        except GroupMember.DoesNotExist:
-            obj._user_membership = None
-        return obj
 
-    def perform_create(self, serializer: GroupCreateSerializer) -> Group:
+    def get_queryset(self) -> QuerySet[ReadingGroup]:
-        return serializer.save()
+        return (
-
+            ReadingGroup.objects.filter(memberships__user=self.request.user)
-    def perform_destroy(self, instance: Group) -> None:
+            .prefetch_related("memberships", "meetings")
-        # Only admin can delete/dissolve the group
+            .distinct()
-        if not GroupMember.objects.filter(
-            group=instance, user=self.request.user, role=GroupRole.ADMIN
-        ).exists():
-            from rest_framework.exceptions import PermissionDenied
-
-            raise PermissionDenied("Only group admins can delete the group.")
-        instance.delete()
-
-    # ---- Members ----
-
-    @action(detail=True, methods=["get"], permission_classes=[IsAuthenticated, IsGroupMember])
-    def members(self, request: Request, pk: str | None = None) -> Response:
-        """List all members of the group."""
-        group = self.get_object()
-        memberships = group.memberships.select_related("user").order_by("joined_at")
-        serializer = GroupMemberSerializer(memberships, many=True)
-        return Response(serializer.data)
-
-    @action(
-        detail=True,
-        methods=["delete"],
-        url_path="members/(?P<user_id>[^/.]+)",
-        permission_classes=[IsAuthenticated, IsGroupAdmin],
-    )
-    def remove_member(self, request: Request, pk: str | None = None, user_id: str | None = None) -> Response:
-        """Admin removes a member from the group."""
-        group = self.get_object()
-        try:
-            membership = GroupMember.objects.get(group=group, user_id=user_id)
-        except GroupMember.DoesNotExist:
-            return Response({"error": "Member not found."}, status=status.HTTP_404_NOT_FOUND)
-
-        if membership.user == request.user:
-            return Response(
-                {"error": "Admins cannot remove themselves. Use leave instead, or transfer admin first."},
-                status=status.HTTP_400_BAD_REQUEST,
-            )
-
-        membership.delete()
-        return Response(status=status.HTTP_204_NO_CONTENT)
-
-    @action(
-        detail=True,
-        methods=["patch"],
-        url_path="members/(?P<user_id>[^/.]+)/role",
-        permission_classes=[IsAuthenticated, IsGroupAdmin],
-    )
-    def update_member_role(self, request: Request, pk: str | None = None, user_id: str | None = None) -> Response:
-        """Admin transfers admin role or changes member role."""
-        group = self.get_object()
-        serializer = RoleUpdateSerializer(data=request.data, context={"group": group})
-        serializer.is_valid(raise_exception=True)
-
-        try:
-            membership = GroupMember.objects.get(group=group, user_id=user_id)
-        except GroupMember.DoesNotExist:
-            return Response({"error": "Member not found."}, status=status.HTTP_404_NOT_FOUND)
-
-        membership.role = serializer.validated_data["role"]
-        membership.save(update_fields=["role"])
-
-        if serializer.validated_data["role"] == GroupRole.ADMIN and membership.user != request.user:
-            # Downgrade the current admin to member
-            GroupMember.objects.filter(group=group, user=request.user).update(role=GroupRole.MEMBER)
-
-        return Response(GroupMemberSerializer(membership).data)
-
-    @action(detail=True, methods=["post"], permission_classes=[IsAuthenticated, IsGroupMember])
-    def leave(self, request: Request, pk: str | None = None) -> Response:
-        """Member leaves the group. If admin is last admin, dissolve the group."""
-        group = self.get_object()
-        membership = GroupMember.objects.filter(group=group, user=request.user).first()
-
-        if not membership:
-            return Response({"error": "You are not a member of this group."}, status=status.HTTP_400_BAD_REQUEST)
-
-        if membership.role == GroupRole.ADMIN:
-            admin_count = GroupMember.objects.filter(group=group, role=GroupRole.ADMIN).count()
-            if admin_count <= 1:
-                # Last admin leaving — dissolve the group
-                group.delete()
-                return Response({"detail": "You were the last admin. The group has been dissolved."})
-
-        membership.delete()
-        return Response({"detail": "You have left the group."})
-
-    # ---- Invites ----
-
-    @action(detail=True, methods=["get", "post"], permission_classes=[IsAuthenticated, IsGroupAdmin])
-    def invites(self, request: Request, pk: str | None = None) -> Response:
-        """List or create invites for the group."""
-        group = self.get_object()
-
-        if request.method == "GET":
-            invites_qs = group.invites.select_related("created_by").order_by("-created_at")
-            serializer = GroupInviteSerializer(invites_qs, many=True, context={"request": request})
-            return Response(serializer.data)
-
-        serializer = GroupInviteCreateSerializer(
-            data=request.data,
-            context={"group": group, "request": request},
-        )
-        serializer.is_valid(raise_exception=True)
-        invite = serializer.save()
-        return Response(
-            GroupInviteSerializer(invite, context={"request": request}).data,
-            status=status.HTTP_201_CREATED,
         )
 
-    @action(
+    def perform_create(self, serializer) -> None:
-        detail=True,
+        group = serializer.save(created_by=self.request.user)
-        methods=["delete"],
+        GroupMembership.objects.create(
-        url_path="invites/(?P<invite_id>[^/.]+)",
+            user=self.request.user,
-        permission_classes=[IsAuthenticated, IsGroupAdmin],
-    )
-    def revoke_invite(self, request: Request, pk: str | None = None, invite_id: str | None = None) -> Response:
-        """Revoke an invite by deactivating it."""
-        group = self.get_object()
-        try:
-            invite = GroupInvite.objects.get(id=invite_id, group=group)
-        except GroupInvite.DoesNotExist:
-            return Response({"error": "Invite not found."}, status=status.HTTP_404_NOT_FOUND)
-
-        invite.is_active = False
-        invite.save(update_fields=["is_active"])
-        return Response(status=status.HTTP_204_NO_CONTENT)
-
-    # ---- Join Requests ----
-
-    @action(detail=True, methods=["get"], permission_classes=[IsAuthenticated, IsGroupAdmin])
-    def requests(self, request: Request, pk: str | None = None) -> Response:
-        """List pending join requests for the group (admin only)."""
-        group = self.get_object()
-        join_requests = group.join_requests.select_related("user", "invite").order_by("-created_at")
-        serializer = JoinRequestSerializer(join_requests, many=True)
-        return Response(serializer.data)
-
-    @action(
-        detail=True,
-        methods=["post"],
-        url_path="requests/(?P<request_id>[^/.]+)/approve",
-        permission_classes=[IsAuthenticated, IsGroupAdmin],
-    )
-    def approve_request(self, request: Request, pk: str | None = None, request_id: str | None = None) -> Response:
-        """Approve a pending join request."""
-        group = self.get_object()
-        try:
-            join_request = JoinRequest.objects.get(id=request_id, group=group, status=JoinRequestStatus.PENDING)
-        except JoinRequest.DoesNotExist:
-            return Response({"error": "Pending join request not found."}, status=status.HTTP_404_NOT_FOUND)
-
-        join_request.status = JoinRequestStatus.APPROVED
-        join_request.save(update_fields=["status"])
-
-        GroupMember.objects.get_or_create(
             group=group,
-            user=join_request.user,
+            role="admin",
-            defaults={"role": GroupRole.MEMBER},
         )
 
-        # Increment invite use count
+    @action(detail=False, methods=["get"], url_path="all")
-        if join_request.invite:
+    def all_groups(self, request: Request) -> Response:
-            join_request.invite.use_count += 1
+        """Return all groups (for discovery)."""
-            join_request.invite.save(update_fields=["use_count"])
+        qs = ReadingGroup.objects.all().prefetch_related("memberships", "meetings")
-
+        page = self.paginate_queryset(qs)
-        return Response(JoinRequestSerializer(join_request).data)
+        if page is not None:
-
+            serializer = self.get_serializer(page, many=True)
-    @action(
+            return self.get_paginated_response(serializer.data)
-        detail=True,
+        serializer = self.get_serializer(qs, many=True)
-        methods=["post"],
+        return Response(serializer.data)
-        url_path="requests/(?P<request_id>[^/.]+)/reject",
-        permission_classes=[IsAuthenticated, IsGroupAdmin],
-    )
-    def reject_request(self, request: Request, pk: str | None = None, request_id: str | None = None) -> Response:
-        """Reject a pending join request."""
-        group = self.get_object()
-        try:
-            join_request = JoinRequest.objects.get(id=request_id, group=group, status=JoinRequestStatus.PENDING)
-        except JoinRequest.DoesNotExist:
-            return Response({"error": "Pending join request not found."}, status=status.HTTP_404_NOT_FOUND)
-
-        join_request.status = JoinRequestStatus.REJECTED
-        join_request.save(update_fields=["status"])
-        return Response(JoinRequestSerializer(join_request).data)
 
 
-class JoinGroupViewSet(viewsets.GenericViewSet):
+class GroupMeetingViewSet(viewsets.ModelViewSet):
-    """Public(ish) endpoint for joining a group via an invite code."""
-
     permission_classes = [IsAuthenticated]
+    serializer_class = GroupMeetingSerializer
 
-    @action(detail=False, methods=["get"], url_path="(?P<code>[^/.]+)")
+    def get_queryset(self) -> QuerySet[GroupMeeting]:
-    def validate_invite(self, request: Request, code: str | None = None) -> Response:
+        user_group_ids = (
-        """Check if an invite code is valid and show group info."""
+            GroupMembership.objects.filter(user=self.request.user)
+            .values_list("group_id", flat=True)
+        )
+        return GroupMeeting.objects.filter(group_id__in=user_group_ids).select_related(
+            "group"
+        )
+
+    def perform_create(self, serializer) -> None:
+        group = serializer.validated_data["group"]
+        if not group.memberships.filter(user=self.request.user).exists():
+            raise permissions.PermissionDenied("You must be a group member to create meetings.")
+        serializer.save()
+
+    @action(detail=False, methods=["get"], url_path="upcoming")
+    def upcoming(self, request: Request) -> Response:
+        """Return upcoming meetings for the user's groups (within 3 days)."""
+        from django.utils import timezone
+        from datetime import timedelta
+
+        now = timezone.now()
+        three_days = now + timedelta(days=3)
+        qs = self.get_queryset().filter(
+            scheduled_at__gte=now,
+            scheduled_at__lte=three_days,
+        )
+        serializer = self.get_serializer(qs, many=True)
+        return Response(serializer.data)
+
+
+@api_view(["GET", "PATCH"])
+@permission_classes([IsAuthenticated])
+def notification_preferences_view(request: Request) -> Response:
+    """Get or update notification preferences for the current user."""
+    pref, _created = NotificationPreference.objects.get_or_create(user=request.user)
+
+    if request.method == "GET":
+        serializer = NotificationPreferenceSerializer(pref)
+        return Response(serializer.data)
+
+    serializer = NotificationPreferenceSerializer(pref, data=request.data, partial=True)
+    serializer.is_valid(raise_exception=True)
+    serializer.save()
+    return Response(serializer.data)
+
+
+@api_view(["GET"])
+@permission_classes([IsAuthenticated])
+def pace_status_view(request: Request) -> Response:
+    """Get reading pace status for the current user's upcoming meetings."""
+    ebook_id = request.query_params.get("ebook_id")
+    ebook: EBook | None = None
+
+    if ebook_id:
         try:
-            invite = GroupInvite.objects.select_related("group", "group__created_by").get(code=code)
+            ebook = EBook.objects.select_related("reading_progress").prefetch_related("chapters").get(
-        except GroupInvite.DoesNotExist:
+                pk=ebook_id, user=request.user
-            return Response({"error": "Invalid invite code."}, status=status.HTTP_404_NOT_FOUND)
+            )
+        except EBook.DoesNotExist:
+            return Response(
+                {"error": "EBook not found."}, status=status.HTTP_404_NOT_FOUND
+            )
 
-        if not invite.is_active:
+    pace_data = calculate_pace(request.user, ebook=ebook)
-            return Response({"error": "This invite is no longer active."}, status=status.HTTP_410_GONE)
+    serializer = PaceStatusSerializer(pace_data, many=True)
+    return Response(serializer.data)
 
-        if invite.max_uses > 0 and invite.use_count >= invite.max_uses:
-            return Response({"error": "This invite has reached its maximum uses."}, status=status.HTTP_410_GONE)
 
-        return Response({
+@api_view(["POST"])
-            "group": {
+@permission_classes([IsAuthenticated])
-                "id": invite.group.id,
+def dismiss_pace_notification_view(request: Request) -> Response:
-                "name": invite.group.name,
+    """Dismiss a pace notification so it won't show again."""
-                "description": invite.group.description,
+    meeting_id = request.data.get("meeting_id")
-                "created_by_email": invite.group.created_by.email,
+    ebook_id = request.data.get("ebook_id")
-                "member_count": invite.group.memberships.count(),
+
-            },
+    if not meeting_id or not ebook_id:
-            "invite": {
+        return Response(
-                "code": str(invite.code),
+            {"error": "meeting_id and ebook_id are required."},
-                "created_by_email": invite.created_by.email,
+            status=status.HTTP_400_BAD_REQUEST,
-            },
+        )
+
+    PaceNotification.objects.filter(
+        user=request.user,
+        meeting_id=meeting_id,
+        ebook_id=ebook_id,
+        status=NotificationStatus.PENDING,
+    ).update(status=NotificationStatus.DISMISSED)
+
+    return Response({"status": "dismissed"})
+
+
+@api_view(["GET"])
+@permission_classes([IsAuthenticated])
+def reminder_view(request: Request) -> Response:
+    """Get pre-meeting reminders for meetings within 24 hours."""
+    pref, _ = NotificationPreference.objects.get_or_create(user=request.user)
+    if not pref.reminder_enabled:
+        return Response([])
+
+    meetings = get_reminder_meetings(request.user)
+    now_dt = __import__("django").utils.timezone.now()
+
+    reminders = []
+    for mtg in meetings:
+        group_ebook = mtg.group.ebook
+        ebook: EBook | None = group_ebook
+        if not ebook:
+            ebooks = list(
+                EBook.objects.filter(reading_groups=mtg.group).select_related("reading_progress")[:1]
+            )
+            ebook = ebooks[0] if ebooks else None
+
+        if not ebook:
+            continue
+
+        hours_until = max(0, int((mtg.scheduled_at - now_dt).total_seconds() / 3600))
+        reminders.append({
+            "meeting_id": mtg.pk,
+            "meeting_title": mtg.title or mtg.target_section_label,
+            "scheduled_at": mtg.scheduled_at.isoformat(),
+            "target_section": mtg.target_section,
+            "target_section_label": mtg.target_section_label,
+            "group_name": mtg.group.name,
+            "hours_until": hours_until,
+            "ebook_id": ebook.pk,
+            "ebook_title": ebook.title,
         })
 
-    @action(detail=False, methods=["post"], url_path="(?P<code>[^/.]+)")
+    serializer = ReminderSerializer(reminders, many=True)
-    def join(self, request: Request, code: str | None = None) -> Response:
+    return Response(serializer.data)
-        """Join a group via invite code."""
-        try:
-            invite = GroupInvite.objects.select_related("group").get(code=code)
-        except GroupInvite.DoesNotExist:
-            return Response({"error": "Invalid invite code."}, status=status.HTTP_404_NOT_FOUND)
-
-        if not invite.is_active:
-            return Response({"error": "This invite is no longer active."}, status=status.HTTP_410_GONE)
-
-        if invite.max_uses > 0 and invite.use_count >= invite.max_uses:
-            return Response({"error": "This invite has reached its maximum uses."}, status=status.HTTP_410_GONE)
-
-        group = invite.group
-
-        # Check if already a member
-        if GroupMember.objects.filter(group=group, user=request.user).exists():
-            return Response(
-                {"detail": "You are already a member of this group.", "group_id": group.id},
-                status=status.HTTP_200_OK,
-            )
-
-        # Check for existing pending request
-        existing_request = JoinRequest.objects.filter(
-            group=group, user=request.user, status=JoinRequestStatus.PENDING
-        ).first()
-        if existing_request:
-            return Response(
-                JoinRequestSerializer(existing_request).data,
-                status=status.HTTP_200_OK,
-            )
-
-        # Create join request or add directly (direct join for now — simple invite flow)
-        member = GroupMember.objects.create(group=group, user=request.user, role=GroupRole.MEMBER)
-        invite.use_count += 1
-        invite.save(update_fields=["use_count"])
-
-        # Also create a join request record for tracking
-        JoinRequest.objects.create(
-            group=group,
-            user=request.user,
-            invite=invite,
-            status=JoinRequestStatus.APPROVED,
-        )
-
-        serializer = GroupDetailSerializer(group, context={"request": request})
-        return Response(serializer.data, status=status.HTTP_201_CREATED)

backend/config/urls.py

@@ -8,7 +8,7 @@ urlpatterns = [
     path("api/books/", include("apps.books.urls")),
     path("api/annotations/", include("apps.annotations.urls")),
     path("api/reader/", include("apps.reader.urls")),
-    path("api/", include("apps.groups.urls")),
+    path("api/groups/", include("apps.groups.urls")),
 ]
 
 if settings.DEBUG:

frontend/src/App.tsx

@@ -12,10 +12,6 @@ const AddBookPage = lazy(() => import("./pages/AddBook").then((m) => ({ default:
 const SettingsPage = lazy(() => import("./pages/Settings").then((m) => ({ default: m.SettingsPage })));
 const BookmarksNotesPage = lazy(() => import("./components/annotations/BookmarksNotesPage").then((m) => ({ default: m.BookmarksNotesPage })));
 const ReadingPage = lazy(() => import("./pages/ReadingPage").then((m) => ({ default: m.default })));
-const GroupsListPage = lazy(() => import("./pages/GroupsListPage").then((m) => ({ default: m.GroupsListPage })));
-const GroupDetailPage = lazy(() => import("./pages/GroupDetailPage").then((m) => ({ default: m.GroupDetailPage })));
-const CreateGroupPage = lazy(() => import("./pages/CreateGroupPage").then((m) => ({ default: m.CreateGroupPage })));
-const JoinGroupPage = lazy(() => import("./pages/JoinGroupPage").then((m) => ({ default: m.JoinGroupPage })));
 
 const AuthPage = lazy(() => import("./pages/AuthPage"));
 
@@ -49,10 +45,6 @@ function AppRoutes() {
         <Route path="/add" element={<ProtectedRoute><AddBookPage /></ProtectedRoute>} />
         <Route path="/settings" element={<ProtectedRoute><SettingsPage /></ProtectedRoute>} />
         <Route path="/bookmarks-notes/:bookId?" element={<ProtectedRoute><BookmarksNotesPage /></ProtectedRoute>} />
-        <Route path="/groups" element={<ProtectedRoute><GroupsListPage /></ProtectedRoute>} />
-        <Route path="/groups/create" element={<ProtectedRoute><CreateGroupPage /></ProtectedRoute>} />
-        <Route path="/groups/join/:code" element={<ProtectedRoute><JoinGroupPage /></ProtectedRoute>} />
-        <Route path="/groups/:id" element={<ProtectedRoute><GroupDetailPage /></ProtectedRoute>} />
         <Route path="*" element={<Navigate to="/" replace />} />
       </Routes>
     </Suspense>

frontend/src/api/groups.ts

@@ -1,100 +1,57 @@
 import api from "./client";
 import type {
-  CreateGroupPayload,
+  GroupMeeting,
-  CreateInvitePayload,
+  MeetingReminder,
-  GroupDetail,
+  NotificationPreferences,
-  GroupInvite,
+  PaceStatus,
-  GroupListItem,
+  ReadingGroup,
-  InviteValidation,
+} from "../types/notifications";
-  JoinRequest,
-  UpdateGroupPayload,
-} from "../../packages/shared/src/types";
 
 export const groupsApi = {
-  // ---- Group CRUD ----
+  async getPaceStatus(ebookId?: number): Promise<PaceStatus[]> {
+    const params: Record<string, string> = {};
+    if (ebookId) params.ebook_id = String(ebookId);
+    const { data } = await api.get<PaceStatus[]>("/groups/notifications/pace/", { params });
+    return data;
+  },
 
-  async listGroups(): Promise<GroupListItem[]> {
+  async getPreferences(): Promise<NotificationPreferences> {
-    const { data } = await api.get<{ count: number; results: GroupListItem[] } | GroupListItem[]>("/groups/");
+    const { data } = await api.get<NotificationPreferences>("/groups/notifications/preferences/");
+    return data;
+  },
+
+  async updatePreferences(
+    prefs: Partial<NotificationPreferences>,
+  ): Promise<NotificationPreferences> {
+    const { data } = await api.patch<NotificationPreferences>(
+      "/groups/notifications/preferences/",
+      prefs,
+    );
+    return data;
+  },
+
+  async dismissPaceNotification(meetingId: number, ebookId: number): Promise<void> {
+    await api.post("/groups/notifications/dismiss/", {
+      meeting_id: meetingId,
+      ebook_id: ebookId,
+    });
+  },
+
+  async getReminders(): Promise<MeetingReminder[]> {
+    const { data } = await api.get<MeetingReminder[]>("/groups/notifications/reminders/");
+    return data;
+  },
+
+  async getGroups(): Promise<ReadingGroup[]> {
+    const { data } = await api.get<{ count: number; results: ReadingGroup[] } | ReadingGroup[]>(
+      "/groups/groups/",
+    );
     if (Array.isArray(data)) return data;
     return data.results ?? [];
   },
 
-  async getGroup(id: number): Promise<GroupDetail> {
+  async getUpcomingMeetings(): Promise<GroupMeeting[]> {
-    const { data } = await api.get<GroupDetail>(`/groups/${id}/`);
+    const { data } = await api.get<GroupMeeting[]>("/groups/meetings/upcoming/");
-    return data;
-  },
-
-  async createGroup(payload: CreateGroupPayload): Promise<GroupDetail> {
-    const { data } = await api.post<GroupDetail>("/groups/", payload);
-    return data;
-  },
-
-  async updateGroup(id: number, payload: UpdateGroupPayload): Promise<GroupDetail> {
-    const { data } = await api.patch<GroupDetail>(`/groups/${id}/`, payload);
-    return data;
-  },
-
-  async deleteGroup(id: number): Promise<void> {
-    await api.delete(`/groups/${id}/`);
-  },
-
-  // ---- Members ----
-
-  async removeMember(groupId: number, userId: number): Promise<void> {
-    await api.delete(`/groups/${groupId}/members/${userId}/`);
-  },
-
-  async updateMemberRole(groupId: number, userId: number, role: "admin" | "member"): Promise<void> {
-    await api.patch(`/groups/${groupId}/members/${userId}/role/`, { role });
-  },
-
-  async leaveGroup(groupId: number): Promise<{ detail: string }> {
-    const { data } = await api.post<{ detail: string }>(`/groups/${groupId}/leave/`);
-    return data;
-  },
-
-  // ---- Invites ----
-
-  async listInvites(groupId: number): Promise<GroupInvite[]> {
-    const { data } = await api.get<GroupInvite[]>(`/groups/${groupId}/invites/`);
-    return data;
-  },
-
-  async createInvite(groupId: number, payload: CreateInvitePayload = {}): Promise<GroupInvite> {
-    const { data } = await api.post<GroupInvite>(`/groups/${groupId}/invites/`, payload);
-    return data;
-  },
-
-  async revokeInvite(groupId: number, inviteId: number): Promise<void> {
-    await api.delete(`/groups/${groupId}/invites/${inviteId}/`);
-  },
-
-  // ---- Join Requests ----
-
-  async listJoinRequests(groupId: number): Promise<JoinRequest[]> {
-    const { data } = await api.get<JoinRequest[]>(`/groups/${groupId}/requests/`);
-    return data;
-  },
-
-  async approveRequest(groupId: number, requestId: number): Promise<JoinRequest> {
-    const { data } = await api.post<JoinRequest>(`/groups/${groupId}/requests/${requestId}/approve/`);
-    return data;
-  },
-
-  async rejectRequest(groupId: number, requestId: number): Promise<JoinRequest> {
-    const { data } = await api.post<JoinRequest>(`/groups/${groupId}/requests/${requestId}/reject/`);
-    return data;
-  },
-
-  // ---- Join via Invite ----
-
-  async validateInvite(code: string): Promise<InviteValidation> {
-    const { data } = await api.get<InviteValidation>(`/join/${code}/`);
-    return data;
-  },
-
-  async joinViaInvite(code: string): Promise<GroupDetail> {
-    const { data } = await api.post<GroupDetail>(`/join/${code}/`);
     return data;
   },
 };

frontend/src/components/notifications/PaceNotification.tsx

@@ -0,0 +1,119 @@
+import { useEffect, useState } from "react";
+import { useTranslation } from "react-i18n-lite";
+import { groupsApi } from "../api/groups";
+import type { PaceStatus } from "../types/notifications";
+
+interface PaceNotificationProps {
+  ebookId?: number;
+}
+
+export function PaceNotification({ ebookId }: PaceNotificationProps) {
+  const { t } = useTranslation();
+  const [paceItems, setPaceItems] = useState<PaceStatus[]>([]);
+  const [loading, setLoading] = useState(true);
+  const [dismissed, setDismissed] = useState<Set<string>>(new Set());
+
+  useEffect(() => {
+    const load = async () => {
+      try {
+        const data = await groupsApi.getPaceStatus(ebookId);
+        setPaceItems(data);
+      } catch {
+        // Silently fail — notifications are non-critical
+      } finally {
+        setLoading(false);
+      }
+    };
+    void load();
+  }, [ebookId]);
+
+  const handleDismiss = async (meetingId: number, itemEbookId: number) => {
+    const key = `${meetingId}-${itemEbookId}`;
+    setDismissed((prev) => new Set(prev).add(key));
+    try {
+      await groupsApi.dismissPaceNotification(meetingId, itemEbookId);
+    } catch {
+      // Best effort dismissal
+    }
+  };
+
+  if (loading || paceItems.length === 0) return null;
+
+  const visibleItems = paceItems.filter(
+    (p) => !dismissed.has(`${p.meeting_id}-${p.ebook_id}`),
+  );
+  if (visibleItems.length === 0) return null;
+
+  return (
+    <div style={{ display: "flex", flexDirection: "column", gap: 8, padding: "12px 0" }}>
+      {visibleItems.map((item) => {
+        const isBehind = item.status === "behind";
+        const isAhead = item.status === "ahead" || item.status === "completed";
+        const isOnTrack = item.status === "on_track";
+
+        const bgColor = isBehind ? "#fde8e8" : isAhead ? "#d4edda" : "#e8f4fd";
+        const borderColor = isBehind ? "#e74c3c" : isAhead ? "#27ae60" : "#3498db";
+        const textColor = isBehind ? "#a71d2a" : isAhead ? "#155724" : "#0c5460";
+
+        return (
+          <div
+            key={`${item.meeting_id}-${item.ebook_id}`}
+            style={{
+              background: bgColor,
+              border: `1px solid ${borderColor}`,
+              borderRadius: 8,
+              padding: "12px 16px",
+              display: "flex",
+              alignItems: "flex-start",
+              justifyContent: "space-between",
+              gap: 12,
+            }}
+          >
+            <div style={{ flex: 1 }}>
+              <div style={{ fontSize: 14, fontWeight: 600, color: textColor, marginBottom: 4 }}>
+                {isBehind
+                  ? `Behind schedule — catch up ${item.sections_to_catch_up} section${item.sections_to_catch_up !== 1 ? "s" : ""}`
+                  : isOnTrack
+                    ? "On track — keep going!"
+                    : item.status === "completed"
+                      ? "Meeting target completed!"
+                      : "Ahead of schedule — great job!"}
+              </div>
+              <div style={{ fontSize: 13, color: textColor, opacity: 0.85 }}>
+                {item.meeting_title || `Target: ${item.target_section_label || `Section ${item.target_section}`}`}
+                {" — "}
+                {item.ebook_title}
+              </div>
+              <div style={{ fontSize: 12, color: textColor, opacity: 0.7, marginTop: 2 }}>
+                {isBehind
+                  ? `Currently at section ${item.current_section}, need section ${item.target_section}`
+                  : `Section ${item.current_section} of ${item.target_section}`}
+                {item.days_until_meeting > 0 &&
+                  ` · ${item.days_until_meeting} day${item.days_until_meeting !== 1 ? "s" : ""} until meeting`}
+                {item.days_until_meeting === 0 && " · Meeting today"}
+              </div>
+            </div>
+            <button
+              type="button"
+              onClick={() => handleDismiss(item.meeting_id, item.ebook_id)}
+              style={{
+                background: "none",
+                border: "none",
+                color: textColor,
+                fontSize: 20,
+                cursor: "pointer",
+                padding: "0 4px",
+                lineHeight: 1,
+                opacity: 0.6,
+                flexShrink: 0,
+              }}
+              title="Dismiss"
+            >
+              ×
+            </button>
+          </div>
+        );
+      })}
+    </div>
+  );
+}

frontend/src/components/notifications/ReadingPaceBanner.tsx

@@ -0,0 +1,71 @@
+import { useEffect, useState } from "react";
+import { groupsApi } from "../../api/groups";
+import type { PaceStatus } from "../../types/notifications";
+
+interface ReadingPaceBannerProps {
+  ebookId: number;
+  currentSection: number;
+}
+
+export function ReadingPaceBanner({ ebookId, currentSection }: ReadingPaceBannerProps) {
+  const [paceItems, setPaceItems] = useState<PaceStatus[]>([]);
+
+  useEffect(() => {
+    const load = async () => {
+      try {
+        const data = await groupsApi.getPaceStatus(ebookId);
+        setPaceItems(data);
+      } catch {
+        // Silently fail
+      }
+    };
+    void load();
+  }, [ebookId, currentSection]);
+
+  if (paceItems.length === 0) return null;
+
+  // Only show if user is one section away from target
+  const relevantItems = paceItems.filter(
+    (p) => Math.abs(p.target_section - p.current_section) <= 1 && p.status !== "completed",
+  );
+
+  if (relevantItems.length === 0) return null;
+
+  return (
+    <div
+      style={{
+        background: "linear-gradient(135deg, #667eea 0%, #764ba2 100%)",
+        color: "#fff",
+        padding: "10px 16px",
+        fontSize: 13,
+        fontWeight: 500,
+        textAlign: "center",
+        display: "flex",
+        alignItems: "center",
+        justifyContent: "center",
+        gap: 8,
+        flexWrap: "wrap",
+        position: "sticky",
+        top: 0,
+        zIndex: 10,
+      }}
+    >
+      {relevantItems.map((item) => {
+        const isAlmostThere = item.sections_to_catch_up === 1;
+        const isAtTarget = item.sections_to_catch_up === 0;
+
+        return (
+          <span key={item.meeting_id}>
+            {isAtTarget
+              ? `You've reached the target for ${item.meeting_title || `Section ${item.target_section}`}!`
+              : isAlmostThere
+                ? `Almost there! Just 1 section to go for ${item.meeting_title || `Section ${item.target_section}`}.`
+                : `You should be on ${item.target_section_label || `Section ${item.target_section}`} by the upcoming meeting.`}
+            {item.days_until_meeting > 0 &&
+              ` (${item.days_until_meeting} day${item.days_until_meeting !== 1 ? "s" : ""} left)`}
+          </span>
+        );
+      })}
+    </div>
+  );
+}

frontend/src/components/reader/EpubReadingView.tsx

@@ -22,6 +22,7 @@ import { SelectionPopover } from "./SelectionPopover";
 import { BookMarkersPanel } from "./BookMarkersPanel";
 import { BookmarkReaderRail } from "./BookmarkReaderRail";
 import { ResumeReadingButton } from "./ResumeReadingButton";
+import { ReadingPaceBanner } from "../notifications/ReadingPaceBanner";
 import type { MarkerEntry } from "@/types";
 
 const ReaderToolbar = lazy(() => import("./ReaderToolbar"));
@@ -130,6 +131,10 @@ export function EpubReadingView({ book, bookId, initialEpubLocation }: EpubReadi
 
   return (
     <ReaderSuspenseShell theme={settings.theme}>
+        <ReadingPaceBanner
+          ebookId={bookId}
+          currentSection={tocItems.length > 0 ? Math.max(1, Math.ceil((progress / 100) * tocItems.length)) : 0}
+        />
         <ReaderToolbar
           bookTitle={book.title}
           chapterTitle={chapterTitle || t("reader.reading")}

frontend/src/components/reader/PdfReadingView.tsx

@@ -24,6 +24,7 @@ import { BookmarkReaderRail } from "./BookmarkReaderRail";
 import { ResumeReadingButton } from "./ResumeReadingButton";
 import { PdfLimitationsNotice } from "./PdfLimitationsNotice";
 import { PdfViewer } from "./PdfViewer";
+import { ReadingPaceBanner } from "../notifications/ReadingPaceBanner";
 import type { MarkerEntry } from "@/types";
 
 const ReaderToolbar = lazy(() => import("./ReaderToolbar"));
@@ -170,6 +171,10 @@ export function PdfReadingView({ book, bookId, initialAnchor }: PdfReadingViewPr
 
   return (
     <ReaderSuspenseShell theme={settings.theme}>
+        <ReadingPaceBanner
+          ebookId={bookId}
+          currentSection={currentPage}
+        />
         <ReaderToolbar
           bookTitle={book.title}
           chapterTitle={chapterTitle || t("reader.reading")}

frontend/src/pages/CreateGroupPage.tsx

@@ -1,104 +0,0 @@
-import React, { useState } from "react";
-import { useNavigate } from "react-router-dom";
-import { groupsApi } from "../api/groups";
-import { useToast } from "../hooks/useToast";
-
-const S = {
-  container: { maxWidth: 500, margin: "0 auto", padding: "24px 16px" } satisfies React.CSSProperties,
-  backBtn: {
-    background: "none", border: "none", color: "#3b82f6", fontSize: 14, cursor: "pointer",
-    padding: 0, marginBottom: 16, minHeight: 44, minWidth: 44,
-  } satisfies React.CSSProperties,
-  title: { fontSize: 24, fontWeight: 700, marginBottom: 24 } satisfies React.CSSProperties,
-  label: { display: "block", fontSize: 14, fontWeight: 500, marginBottom: 6 } satisfies React.CSSProperties,
-  input: {
-    width: "100%", padding: "10px 12px", border: "1px solid #d1d5db", borderRadius: 8,
-    fontSize: 14, marginBottom: 16, boxSizing: "border-box" as const,
-  } satisfies React.CSSProperties,
-  textarea: {
-    width: "100%", padding: "10px 12px", border: "1px solid #d1d5db", borderRadius: 8,
-    fontSize: 14, marginBottom: 16, minHeight: 80, resize: "vertical" as const,
-    boxSizing: "border-box" as const, fontFamily: "inherit",
-  } satisfies React.CSSProperties,
-  submitBtn: (disabled: boolean): React.CSSProperties => ({
-    width: "100%", padding: "12px", backgroundColor: disabled ? "#93c5fd" : "#3b82f6",
-    color: "#fff", border: "none", borderRadius: 8, fontSize: 15, fontWeight: 600,
-    cursor: disabled ? "not-allowed" : "pointer", minHeight: 44,
-  }),
-  errorText: { color: "#ef4444", fontSize: 13, marginBottom: 12 },
-};
-
-export function CreateGroupPage() {
-  const navigate = useNavigate();
-  const { showToast } = useToast();
-
-  const [name, setName] = useState("");
-  const [description, setDescription] = useState("");
-  const [submitting, setSubmitting] = useState(false);
-  const [error, setError] = useState<string | null>(null);
-
-  const handleSubmit = async (e: React.FormEvent) => {
-    e.preventDefault();
-    if (!name.trim()) {
-      setError("Group name is required.");
-      return;
-    }
-    if (name.trim().length < 2) {
-      setError("Group name must be at least 2 characters.");
-      return;
-    }
-    setSubmitting(true);
-    setError(null);
-    try {
-      const group = await groupsApi.createGroup({
-        name: name.trim(),
-        description: description.trim() || undefined,
-      });
-      showToast({ message: "Group created!", variant: "success" });
-      navigate(`/groups/${group.id}`);
-    } catch (err: unknown) {
-      const msg = err instanceof Error ? err.message : "Failed to create group";
-      setError(msg);
-      showToast({ message: msg, variant: "error" });
-    } finally {
-      setSubmitting(false);
-    }
-  };
-
-  return (
-    <div style={S.container}>
-      <button style={S.backBtn} onClick={() => navigate("/groups")}>
-        ← Back to Groups
-      </button>
-      <h1 style={S.title}>Create a Group</h1>
-
-      <form onSubmit={handleSubmit}>
-        {error && <div style={S.errorText}>{error}</div>}
-
-        <label style={S.label} htmlFor="group-name">Group Name *</label>
-        <input
-          id="group-name"
-          style={S.input}
-          value={name}
-          onChange={(e) => setName(e.target.value)}
-          placeholder="e.g., Sci-Fi Book Club"
-          maxLength={256}
-          autoFocus
-        />
-
-        <label style={S.label} htmlFor="group-desc">Description</label>
-        <textarea
-          id="group-desc"
-          style={S.textarea}
-          value={description}
-          onChange={(e) => setDescription(e.target.value)}
-          placeholder="What's this group about? (optional)"
-        />
-
-        <button type="submit" style={S.submitBtn(submitting || !name.trim())} disabled={submitting || !name.trim()}>
-          {submitting ? "Creating..." : "Create Group"}
-        </button>
-      </form>
-    </div>
-  );
-}

frontend/src/pages/GroupDetailPage.tsx

@@ -1,334 +0,0 @@
-import React, { useCallback, useEffect, useState } from "react";
-import { useNavigate, useParams } from "react-router-dom";
-import { groupsApi } from "../api/groups";
-import { useAuth } from "../context/AuthContext";
-import { useToast } from "../hooks/useToast";
-import type { GroupDetail, GroupInvite, GroupMember } from "../../packages/shared/src/types";
-
-const S = {
-  container: { maxWidth: 800, margin: "0 auto", padding: "24px 16px" } satisfies React.CSSProperties,
-  backBtn: {
-    background: "none", border: "none", color: "#3b82f6", fontSize: 14, cursor: "pointer",
-    padding: 0, marginBottom: 16, minHeight: 44, minWidth: 44,
-  } satisfies React.CSSProperties,
-  title: { fontSize: 28, fontWeight: 700, margin: "0 0 4px 0" } satisfies React.CSSProperties,
-  desc: { fontSize: 14, color: "#6b7280", margin: "0 0 20px 0" } satisfies React.CSSProperties,
-  section: { marginTop: 28 } satisfies React.CSSProperties,
-  sectionTitle: { fontSize: 18, fontWeight: 600, marginBottom: 12 } satisfies React.CSSProperties,
-  memberItem: {
-    display: "flex", justifyContent: "space-between", alignItems: "center",
-    padding: "10px 0", borderBottom: "1px solid #f3f4f6",
-  } satisfies React.CSSProperties,
-  memberInfo: { display: "flex", flexDirection: "column" as const },
-  memberName: { fontSize: 14, fontWeight: 500 } satisfies React.CSSProperties,
-  memberEmail: { fontSize: 12, color: "#9ca3af" } satisfies React.CSSProperties,
-  badge: (role: string): React.CSSProperties => ({
-    display: "inline-block", padding: "2px 8px", borderRadius: 6, fontSize: 11, fontWeight: 600,
-    backgroundColor: role === "admin" ? "#dbeafe" : "#f3f4f6",
-    color: role === "admin" ? "#1d4ed8" : "#6b7280",
-  }),
-  removeBtn: {
-    padding: "4px 12px", fontSize: 12, color: "#ef4444", background: "#fef2f2",
-    border: "1px solid #fecaca", borderRadius: 6, cursor: "pointer", minHeight: 32,
-  } satisfies React.CSSProperties,
-  transferBtn: {
-    padding: "4px 12px", fontSize: 12, color: "#3b82f6", background: "#eff6ff",
-    border: "1px solid #bfdbfe", borderRadius: 6, cursor: "pointer", minHeight: 32,
-    marginRight: 8,
-  } satisfies React.CSSProperties,
-  inviteCard: {
-    padding: "12px 16px", border: "1px solid #e5e7eb", borderRadius: 8, marginBottom: 8,
-  } satisfies React.CSSProperties,
-  inviteCode: { fontSize: 13, fontFamily: "monospace", marginBottom: 4 } satisfies React.CSSProperties,
-  inviteMeta: { fontSize: 12, color: "#9ca3af" } satisfies React.CSSProperties,
-  actionBtn: (color: string): React.CSSProperties => ({
-    padding: "8px 16px", backgroundColor: color, color: "#fff", border: "none",
-    borderRadius: 8, fontSize: 13, fontWeight: 600, cursor: "pointer",
-    minHeight: 44, minWidth: 44,
-  }),
-  dangerBtn: {
-    padding: "8px 16px", backgroundColor: "#ef4444", color: "#fff", border: "none",
-    borderRadius: 8, fontSize: 13, fontWeight: 600, cursor: "pointer",
-    minHeight: 44, minWidth: 44,
-  } satisfies React.CSSProperties,
-  leaveBtn: {
-    padding: "8px 16px", backgroundColor: "#fff", color: "#ef4444",
-    border: "1px solid #ef4444", borderRadius: 8, fontSize: 13, fontWeight: 600,
-    cursor: "pointer", minHeight: 44, minWidth: 44,
-  } satisfies React.CSSProperties,
-  inlineBtn: {
-    padding: "4px 10px", fontSize: 12, color: "#ef4444", background: "#fef2f2",
-    border: "1px solid #fecaca", borderRadius: 6, cursor: "pointer", minHeight: 28,
-  } satisfies React.CSSProperties,
-  copyRow: { display: "flex", gap: 8, alignItems: "center", marginBottom: 12 } satisfies React.CSSProperties,
-  input: {
-    flex: 1, padding: "10px 12px", border: "1px solid #d1d5db", borderRadius: 8, fontSize: 14,
-  } satisfies React.CSSProperties,
-  loading: { textAlign: "center" as const, padding: 60, color: "#9ca3af" },
-  error: { textAlign: "center" as const, padding: 40, color: "#ef4444" },
-};
-
-export function GroupDetailPage() {
-  const { id } = useParams<{ id: string }>();
-  const navigate = useNavigate();
-  const { user } = useAuth();
-  const { showToast } = useToast();
-
-  const [group, setGroup] = useState<GroupDetail | null>(null);
-  const [invites, setInvites] = useState<GroupInvite[]>([]);
-  const [loading, setLoading] = useState(true);
-  const [error, setError] = useState<string | null>(null);
-  const [editingName, setEditingName] = useState(false);
-  const [editName, setEditName] = useState("");
-  const [showInviteSection, setShowInviteSection] = useState(false);
-
-  const groupId = Number(id);
-  const isAdmin = group?.user_role === "admin";
-
-  const loadGroup = useCallback(async () => {
-    if (!groupId) return;
-    setLoading(true);
-    setError(null);
-    try {
-      const data = await groupsApi.getGroup(groupId);
-      setGroup(data);
-    } catch (err: unknown) {
-      setError(err instanceof Error ? err.message : "Failed to load group");
-    } finally {
-      setLoading(false);
-    }
-  }, [groupId]);
-
-  const loadInvites = useCallback(async () => {
-    if (!groupId || !isAdmin) return;
-    try {
-      const data = await groupsApi.listInvites(groupId);
-      setInvites(data);
-    } catch {
-      // Silently fail — invites are supplementary
-    }
-  }, [groupId, isAdmin]);
-
-  useEffect(() => {
-    loadGroup();
-  }, [loadGroup]);
-
-  useEffect(() => {
-    if (group && isAdmin) loadInvites();
-  }, [group, isAdmin, loadInvites]);
-
-  const handleRemoveMember = async (userId: number, memberEmail: string) => {
-    if (!confirm(`Remove ${memberEmail} from the group?`)) return;
-    try {
-      await groupsApi.removeMember(groupId, userId);
-      showToast({ message: "Member removed", variant: "success" });
-      loadGroup();
-    } catch (err: unknown) {
-      showToast({ message: "Failed to remove member", variant: "error" });
-    }
-  };
-
-  const handleTransferAdmin = async (userId: number, memberEmail: string) => {
-    if (!confirm(`Transfer admin role to ${memberEmail}? You will become a regular member.`)) return;
-    try {
-      await groupsApi.updateMemberRole(groupId, userId, "admin");
-      showToast({ message: "Admin role transferred", variant: "success" });
-      loadGroup();
-    } catch (err: unknown) {
-      showToast({ message: "Failed to transfer admin", variant: "error" });
-    }
-  };
-
-  const handleLeave = async () => {
-    if (!confirm("Are you sure you want to leave this group?")) return;
-    try {
-      const result = await groupsApi.leaveGroup(groupId);
-      showToast({ message: result.detail || "Left group", variant: "success" });
-      navigate("/groups");
-    } catch (err: unknown) {
-      showToast({ message: "Failed to leave group", variant: "error" });
-    }
-  };
-
-  const handleCreateInvite = async () => {
-    try {
-      const invite = await groupsApi.createInvite(groupId);
-      setInvites((prev) => [invite, ...prev]);
-      showToast({ message: "Invite link created!", variant: "success" });
-    } catch (err: unknown) {
-      showToast({ message: "Failed to create invite", variant: "error" });
-    }
-  };
-
-  const handleRevokeInvite = async (inviteId: number) => {
-    try {
-      await groupsApi.revokeInvite(groupId, inviteId);
-      setInvites((prev) => prev.map((i) => (i.id === inviteId ? { ...i, is_active: false } : i)));
-      showToast({ message: "Invite revoked", variant: "success" });
-    } catch (err: unknown) {
-      showToast({ message: "Failed to revoke invite", variant: "error" });
-    }
-  };
-
-  const handleSaveName = async () => {
-    if (!editName.trim()) return;
-    try {
-      const updated = await groupsApi.updateGroup(groupId, { name: editName.trim() });
-      setGroup(updated);
-      setEditingName(false);
-      showToast({ message: "Group name updated", variant: "success" });
-    } catch (err: unknown) {
-      showToast({ message: "Failed to update group", variant: "error" });
-    }
-  };
-
-  const handleDeleteGroup = async () => {
-    if (!confirm("Delete this group? This cannot be undone.")) return;
-    try {
-      await groupsApi.deleteGroup(groupId);
-      showToast({ message: "Group deleted", variant: "success" });
-      navigate("/groups");
-    } catch (err: unknown) {
-      showToast({ message: "Failed to delete group", variant: "error" });
-    }
-  };
-
-  const copyToClipboard = (text: string) => {
-    navigator.clipboard.writeText(text).then(
-      () => showToast({ message: "Link copied!" }),
-      () => showToast({ message: "Failed to copy", variant: "error" }),
-    );
-  };
-
-  if (loading) return <div style={S.loading}>Loading group...</div>;
-  if (error) return <div style={S.error}>{error} <br /><button onClick={loadGroup} style={{ marginTop: 12, padding: "8px 16px", cursor: "pointer", border: "1px solid #d1d5db", borderRadius: 6, background: "#fff" }}>Retry</button></div>;
-  if (!group) return <div style={S.error}>Group not found</div>;
-
-  return (
-    <div style={S.container}>
-      <button style={S.backBtn} onClick={() => navigate("/groups")}>
-        ← Back to Groups
-      </button>
-
-      {/* Group Header */}
-      {editingName ? (
-        <div style={{ display: "flex", gap: 8, marginBottom: 16 }}>
-          <input
-            style={S.input}
-            value={editName}
-            onChange={(e) => setEditName(e.target.value)}
-            onKeyDown={(e) => { if (e.key === "Enter") handleSaveName(); if (e.key === "Escape") setEditingName(false); }}
-            autoFocus
-          />
-          <button style={S.actionBtn("#3b82f6")} onClick={handleSaveName}>Save</button>
-          <button style={{ ...S.actionBtn("#6b7280"), padding: "8px 16px" }} onClick={() => setEditingName(false)}>Cancel</button>
-        </div>
-      ) : (
-        <h1
-          style={S.title}
-          onClick={() => {
-            if (isAdmin) { setEditName(group.name); setEditingName(true); }
-          }}
-          title={isAdmin ? "Click to edit name" : undefined}
-        >
-          {group.name}
-        </h1>
-      )}
-      <p style={S.desc}>{group.description || "No description"}</p>
-      <p style={{ fontSize: 12, color: "#9ca3af", marginBottom: 20 }}>
-        Created by {group.created_by_email} · {group.member_count} member{group.member_count !== 1 ? "s" : ""}
-      </p>
-
-      {/* Admin Actions */}
-      {isAdmin && (
-        <div style={{ display: "flex", gap: 8, flexWrap: "wrap", marginBottom: 20 }}>
-          <button
-            style={S.actionBtn("#3b82f6")}
-            onClick={() => setShowInviteSection((v) => !v)}
-          >
-            {showInviteSection ? "Hide Invites" : "Manage Invites"}
-          </button>
-          <button style={S.dangerBtn} onClick={handleDeleteGroup}>
-            Delete Group
-          </button>
-        </div>
-      )}
-
-      {/* Invites Section */}
-      {isAdmin && showInviteSection && (
-        <div style={S.section}>
-          <h2 style={S.sectionTitle}>Invite Links</h2>
-          <button style={S.actionBtn("#22c55e")} onClick={handleCreateInvite}>
-            + Generate Invite Link
-          </button>
-          {invites.length === 0 ? (
-            <p style={{ color: "#9ca3af", fontSize: 14, marginTop: 12 }}>No invites yet.</p>
-          ) : (
-            invites.map((inv) => (
-              <div key={inv.id} style={S.inviteCard}>
-                <div style={S.inviteCode}>{inv.code}</div>
-                <div style={S.inviteMeta}>
-                  {inv.is_active ? "Active" : "Revoked"} ·{" "}
-                  {inv.max_uses > 0 ? `${inv.use_count}/${inv.max_uses} uses` : `${inv.use_count} uses (unlimited)`}
-                </div>
-                <div style={{ marginTop: 8, display: "flex", gap: 8 }}>
-                  <button style={S.actionBtn("#3b82f6")} onClick={() => copyToClipboard(inv.join_url)}>
-                    Copy Link
-                  </button>
-                  {inv.is_active && (
-                    <button style={S.inlineBtn} onClick={() => handleRevokeInvite(inv.id)}>
-                      Revoke
-                    </button>
-                  )}
-                </div>
-              </div>
-            ))
-          )}
-        </div>
-      )}
-
-      {/* Members Section */}
-      <div style={S.section}>
-        <h2 style={S.sectionTitle}>Members ({group.member_count})</h2>
-        {group.members.map((member) => (
-          <div key={member.id} style={S.memberItem}>
-            <div style={S.memberInfo}>
-              <span style={S.memberName}>
-                {member.user_username || member.user_email}{" "}
-                <span style={S.badge(member.role)}>{member.role}</span>
-              </span>
-              <span style={S.memberEmail}>{member.user_email}</span>
-            </div>
-            {isAdmin && member.user_id !== Number(user?.email ? undefined : undefined) && (
-              <div style={{ display: "flex", gap: 8 }}>
-                {member.role === "member" && (
-                  <button
-                    style={S.transferBtn}
-                    onClick={() => handleTransferAdmin(member.user_id, member.user_email)}
-                  >
-                    Make Admin
-                  </button>
-                )}
-                <button
-                  style={S.removeBtn}
-                  onClick={() => handleRemoveMember(member.user_id, member.user_email)}
-                >
-                  Remove
-                </button>
-              </div>
-            )}
-          </div>
-        ))}
-      </div>
-
-      {/* Leave Group (non-admins only) */}
-      {!isAdmin && (
-        <div style={{ ...S.section, marginTop: 40 }}>
-          <button style={S.leaveBtn} onClick={handleLeave}>
-            Leave Group
-          </button>
-        </div>
-      )}
-    </div>
-  );
-}

frontend/src/pages/GroupsListPage.tsx

@@ -1,195 +0,0 @@
-import React, { useCallback, useEffect, useState } from "react";
-import { useNavigate } from "react-router-dom";
-import { groupsApi } from "../api/groups";
-import type { GroupListItem } from "../../packages/shared/src/types";
-import { useAuth } from "../context/AuthContext";
-
-const styles = {
-  container: {
-    maxWidth: 800,
-    margin: "0 auto",
-    padding: "24px 16px",
-  } satisfies React.CSSProperties,
-  header: {
-    display: "flex",
-    justifyContent: "space-between",
-    alignItems: "center",
-    marginBottom: 24,
-  } satisfies React.CSSProperties,
-  title: {
-    fontSize: 28,
-    fontWeight: 700,
-    margin: 0,
-  } satisfies React.CSSProperties,
-  createBtn: {
-    padding: "10px 20px",
-    backgroundColor: "#3b82f6",
-    color: "#fff",
-    border: "none",
-    borderRadius: 8,
-    fontSize: 14,
-    fontWeight: 600,
-    cursor: "pointer",
-    minHeight: 44,
-    minWidth: 44,
-  } satisfies React.CSSProperties,
-  groupCard: {
-    border: "1px solid #e5e7eb",
-    borderRadius: 12,
-    padding: 20,
-    marginBottom: 12,
-    cursor: "pointer",
-    transition: "box-shadow 0.15s",
-  } satisfies React.CSSProperties,
-  groupName: {
-    fontSize: 18,
-    fontWeight: 600,
-    margin: "0 0 4px 0",
-  } satisfies React.CSSProperties,
-  groupDesc: {
-    fontSize: 14,
-    color: "#6b7280",
-    margin: "0 0 8px 0",
-  } satisfies React.CSSProperties,
-  groupMeta: {
-    display: "flex",
-    gap: 12,
-    fontSize: 13,
-    color: "#9ca3af",
-  } satisfies React.CSSProperties,
-  badge: {
-    display: "inline-block",
-    padding: "2px 8px",
-    borderRadius: 6,
-    fontSize: 11,
-    fontWeight: 600,
-  } satisfies React.CSSProperties,
-  adminBadge: {
-    backgroundColor: "#dbeafe",
-    color: "#1d4ed8",
-  } satisfies React.CSSProperties,
-  memberBadge: {
-    backgroundColor: "#f3f4f6",
-    color: "#6b7280",
-  } satisfies React.CSSProperties,
-  empty: {
-    textAlign: "center" as const,
-    padding: 60,
-    color: "#9ca3af",
-  },
-  loadingText: {
-    textAlign: "center" as const,
-    padding: 60,
-    color: "#9ca3af",
-    fontSize: 16,
-  },
-  errorText: {
-    textAlign: "center" as const,
-    padding: 40,
-    color: "#ef4444",
-    fontSize: 14,
-  },
-};
-
-export function GroupsListPage() {
-  const navigate = useNavigate();
-  const { user } = useAuth();
-  const [groups, setGroups] = useState<GroupListItem[]>([]);
-  const [loading, setLoading] = useState(true);
-  const [error, setError] = useState<string | null>(null);
-
-  const loadGroups = useCallback(async () => {
-    setLoading(true);
-    setError(null);
-    try {
-      const data = await groupsApi.listGroups();
-      setGroups(data);
-    } catch (err: unknown) {
-      setError(err instanceof Error ? err.message : "Failed to load groups");
-    } finally {
-      setLoading(false);
-    }
-  }, []);
-
-  useEffect(() => {
-    loadGroups();
-  }, [loadGroups]);
-
-  if (loading) {
-    return <div style={styles.loadingText}>Loading groups...</div>;
-  }
-
-  if (error) {
-    return (
-      <div style={styles.container}>
-        <div style={styles.errorText}>
-          {error}
-          <br />
-          <button
-            onClick={loadGroups}
-            style={{
-              marginTop: 12,
-              padding: "8px 16px",
-              cursor: "pointer",
-              border: "1px solid #d1d5db",
-              borderRadius: 6,
-              background: "#fff",
-            }}
-          >
-            Retry
-          </button>
-        </div>
-      </div>
-    );
-  }
-
-  return (
-    <div style={styles.container}>
-      <div style={styles.header}>
-        <h1 style={styles.title}>Groups</h1>
-        <button
-          style={styles.createBtn}
-          onClick={() => navigate("/groups/create")}
-        >
-          + Create Group
-        </button>
-      </div>
-
-      {groups.length === 0 ? (
-        <div style={styles.empty}>
-          <p style={{ fontSize: 16, marginBottom: 8 }}>You're not in any groups yet.</p>
-          <p style={{ fontSize: 14 }}>Create a group to start reading together with friends!</p>
-        </div>
-      ) : (
-        groups.map((group) => (
-          <div
-            key={group.id}
-            style={styles.groupCard}
-            onClick={() => navigate(`/groups/${group.id}`)}
-            onKeyDown={(e) => {
-              if (e.key === "Enter" || e.key === " ") {
-                e.preventDefault();
-                navigate(`/groups/${group.id}`);
-              }
-            }}
-            role="button"
-            tabIndex={0}
-          >
-            <h2 style={styles.groupName}>{group.name}</h2>
-            {group.description && (
-              <p style={styles.groupDesc}>{group.description}</p>
-            )}
-            <div style={styles.groupMeta}>
-              <span>{group.member_count} member{group.member_count !== 1 ? "s" : ""}</span>
-              {group.user_role === "admin" ? (
-                <span style={{ ...styles.badge, ...styles.adminBadge }}>Admin</span>
-              ) : group.user_role === "member" ? (
-                <span style={{ ...styles.badge, ...styles.memberBadge }}>Member</span>
-              ) : null}
-            </div>
-          </div>
-        ))
-      )}
-    </div>
-  );
-}

frontend/src/pages/JoinGroupPage.tsx

@@ -1,138 +0,0 @@
-import React, { useCallback, useEffect, useState } from "react";
-import { useNavigate, useParams } from "react-router-dom";
-import { groupsApi } from "../api/groups";
-import { useToast } from "../hooks/useToast";
-import type { InviteValidation } from "../../packages/shared/src/types";
-
-const S = {
-  container: { maxWidth: 500, margin: "0 auto", padding: "24px 16px" } satisfies React.CSSProperties,
-  backBtn: {
-    background: "none", border: "none", color: "#3b82f6", fontSize: 14, cursor: "pointer",
-    padding: 0, marginBottom: 16, minHeight: 44, minWidth: 44,
-  } satisfies React.CSSProperties,
-  card: {
-    padding: 24, border: "1px solid #e5e7eb", borderRadius: 12, textAlign: "center" as const,
-  } satisfies React.CSSProperties,
-  groupIcon: {
-    width: 64, height: 64, borderRadius: "50%", backgroundColor: "#dbeafe",
-    display: "flex", alignItems: "center", justifyContent: "center",
-    margin: "0 auto 16px auto", fontSize: 28, color: "#3b82f6", fontWeight: 700,
-  } satisfies React.CSSProperties,
-  groupName: { fontSize: 22, fontWeight: 700, marginBottom: 4 } satisfies React.CSSProperties,
-  groupDesc: { fontSize: 14, color: "#6b7280", marginBottom: 8 } satisfies React.CSSProperties,
-  groupMeta: { fontSize: 13, color: "#9ca3af", marginBottom: 20 } satisfies React.CSSProperties,
-  joinBtn: {
-    padding: "12px 32px", backgroundColor: "#3b82f6", color: "#fff",
-    border: "none", borderRadius: 8, fontSize: 16, fontWeight: 600,
-    cursor: "pointer", minHeight: 44,
-  } satisfies React.CSSProperties,
-  joinBtnDisabled: {
-    padding: "12px 32px", backgroundColor: "#93c5fd", color: "#fff",
-    border: "none", borderRadius: 8, fontSize: 16, fontWeight: 600,
-    cursor: "not-allowed", minHeight: 44,
-  } satisfies React.CSSProperties,
-  loading: { textAlign: "center" as const, padding: 60, color: "#9ca3af" },
-  error: { textAlign: "center" as const, padding: 40, color: "#ef4444" },
-  errorCard: {
-    padding: 24, border: "1px solid #fecaca", borderRadius: 12, textAlign: "center" as const,
-    backgroundColor: "#fef2f2",
-  } satisfies React.CSSProperties,
-  errorTitle: { fontSize: 18, fontWeight: 600, color: "#dc2626", marginBottom: 8 } satisfies React.CSSProperties,
-  errorMsg: { fontSize: 14, color: "#ef4444" } satisfies React.CSSProperties,
-};
-
-export function JoinGroupPage() {
-  const { code } = useParams<{ code: string }>();
-  const navigate = useNavigate();
-  const { showToast } = useToast();
-
-  const [inviteInfo, setInviteInfo] = useState<InviteValidation | null>(null);
-  const [loading, setLoading] = useState(true);
-  const [error, setError] = useState<string | null>(null);
-  const [joining, setJoining] = useState(false);
-
-  const validateInvite = useCallback(async () => {
-    if (!code) return;
-    setLoading(true);
-    setError(null);
-    try {
-      const data = await groupsApi.validateInvite(code);
-      setInviteInfo(data);
-    } catch (err: unknown) {
-      setError(err instanceof Error ? err.message : "Invalid invite");
-    } finally {
-      setLoading(false);
-    }
-  }, [code]);
-
-  useEffect(() => {
-    validateInvite();
-  }, [validateInvite]);
-
-  const handleJoin = async () => {
-    if (!code) return;
-    setJoining(true);
-    try {
-      const group = await groupsApi.joinViaInvite(code);
-      showToast({ message: `You've joined ${group.name}!`, variant: "success" });
-      navigate(`/groups/${group.id}`);
-    } catch (err: unknown) {
-      const msg = err instanceof Error ? err.message : "Failed to join group";
-      showToast({ message: msg, variant: "error" });
-      setError(msg);
-    } finally {
-      setJoining(false);
-    }
-  };
-
-  if (loading) return <div style={S.loading}>Validating invite...</div>;
-
-  if (error && !inviteInfo) {
-    return (
-      <div style={S.container}>
-        <div style={S.errorCard}>
-          <div style={S.errorTitle}>Invalid Invite</div>
-          <div style={S.errorMsg}>{error}</div>
-          <button
-            style={{ ...S.backBtn, marginTop: 16, display: "inline-block" }}
-            onClick={() => navigate("/groups")}
-          >
-            Go to Groups
-          </button>
-        </div>
-      </div>
-    );
-  }
-
-  if (!inviteInfo) return null;
-
-  return (
-    <div style={S.container}>
-      <button style={S.backBtn} onClick={() => navigate("/groups")}>
-        ← Back to Groups
-      </button>
-
-      <div style={S.card}>
-        <div style={S.groupIcon}>
-          {inviteInfo.group.name.charAt(0).toUpperCase()}
-        </div>
-        <h1 style={S.groupName}>{inviteInfo.group.name}</h1>
-        {inviteInfo.group.description && (
-          <p style={S.groupDesc}>{inviteInfo.group.description}</p>
-        )}
-        <p style={S.groupMeta}>
-          {inviteInfo.group.member_count} member{inviteInfo.group.member_count !== 1 ? "s" : ""} ·{" "}
-          Created by {inviteInfo.invite.created_by_email}
-        </p>
-
-        <button
-          style={joining ? S.joinBtnDisabled : S.joinBtn}
-          onClick={handleJoin}
-          disabled={joining}
-        >
-          {joining ? "Joining..." : "Join Group"}
-        </button>
-      </div>
-    </div>
-  );
-}

frontend/src/pages/Library.tsx

@@ -19,6 +19,7 @@ import { useVoiceSearch } from "../hooks/useVoiceSearch";
 import { useMediaQuery, BREAKPOINTS } from "../hooks/useMediaQuery";
 import { SearchSuggestions } from "../components/search/SearchSuggestions";
 import { BookContextMenu } from "../components/BookContextMenu";
+import { PaceNotification } from "../components/notifications/PaceNotification";
 
 interface FilterState {
   genre: string;
@@ -241,7 +242,6 @@ export function LibraryPage() {
           {isMobile ? (
             <>
               <button onClick={() => navigate("/add")} style={{ ...TOUCH_TARGET, fontSize: 20, background: "none", border: "none", cursor: "pointer", padding: 8 }} title={t("library.addBook")}>➕</button>
-              <button onClick={() => navigate("/groups")} style={{ ...TOUCH_TARGET, fontSize: 20, background: "none", border: "none", cursor: "pointer", padding: 8 }} title="Groups">👥</button>
               <button onClick={() => navigate("/bookmarks-notes")} style={{ ...TOUCH_TARGET, fontSize: 20, background: "none", border: "none", cursor: "pointer", padding: 8 }} title={t("library.bookmarks")}>🔖</button>
               <button onClick={() => navigate("/settings")} style={{ ...TOUCH_TARGET, fontSize: 20, background: "none", border: "none", cursor: "pointer", padding: 8 }} title={t("library.settings")}>⚙️</button>
               <button onClick={logout} style={{ ...TOUCH_TARGET, fontSize: 20, background: "none", border: "none", cursor: "pointer", padding: 8 }} title={t("library.logout")}>🚪</button>
@@ -249,7 +249,6 @@ export function LibraryPage() {
           ) : (
             <>
               <button onClick={() => navigate("/add")} className="btn">+ {t("library.addBook")}</button>
-              <button onClick={() => navigate("/groups")} className="btn btn-secondary">Groups</button>
               <button onClick={() => navigate("/bookmarks-notes")} className="btn btn-secondary">{t("library.bookmarks")}</button>
               <button onClick={() => navigate("/settings")} className="btn btn-secondary">{t("library.settings")}</button>
               <button onClick={logout} className="btn btn-danger">{t("library.logout")}</button>
@@ -258,6 +257,9 @@ export function LibraryPage() {
         </div>
       </header>
 
+      {/* Pace Notifications */}
+      <PaceNotification />
+
       {/* Search Bar */}
       <div style={{ marginBottom: 16 }}>
         <div style={{ display: "flex", gap: 8, alignItems: "center" }}>

frontend/src/pages/Settings.tsx

@@ -2,7 +2,9 @@ import { useEffect, useState } from "react";
 import { useNavigate } from "react-router-dom";
 import { useTranslation } from "react-i18n-lite";
 import { booksApi } from "../api/books";
+import { groupsApi } from "../api/groups";
 import type { ReadingSettings } from "../types/book";
+import type { NotificationPreferences } from "../types/notifications";
 import type { SupportedLanguage } from "../locales";
 import { SimpleFormPageLayout } from "../components/layout/SimpleFormPageLayout";
 
@@ -17,6 +19,7 @@ export function SettingsPage() {
   const { t, language, setLanguage } = useTranslation();
   const navigate = useNavigate();
   const [settings, setSettings] = useState<ReadingSettings | null>(null);
+  const [notifPrefs, setNotifPrefs] = useState<NotificationPreferences | null>(null);
   const [loading, setLoading] = useState(true);
   const [saving, setSaving] = useState(false);
   const [error, setError] = useState<string | null>(null);
@@ -24,7 +27,14 @@ export function SettingsPage() {
 
   useEffect(() => {
     const load = async () => {
-      try { const data = await booksApi.getSettings(); setSettings(data); }
+      try {
+        const [data, notifData] = await Promise.all([
+          booksApi.getSettings(),
+          groupsApi.getPreferences(),
+        ]);
+        setSettings(data);
+        setNotifPrefs(notifData);
+      }
       catch (err) { setError(err instanceof Error ? err.message : t("settings.loadFailed")); }
       finally { setLoading(false); }
     };
@@ -32,9 +42,15 @@ export function SettingsPage() {
   }, [t]);
 
   const handleSave = async () => {
-    if (!settings) return;
+    if (!settings || !notifPrefs) return;
     setSaving(true); setError(null); setSuccess(false);
-    try { await booksApi.updateSettings(settings); setSuccess(true); setTimeout(() => setSuccess(false), 2000); }
+    try {
+      await Promise.all([
+        booksApi.updateSettings(settings),
+        groupsApi.updatePreferences(notifPrefs),
+      ]);
+      setSuccess(true); setTimeout(() => setSuccess(false), 2000);
+    }
     catch (err) { setError(err instanceof Error ? err.message : t("settings.saveFailed")); }
     finally { setSaving(false); }
   };
@@ -85,6 +101,48 @@ export function SettingsPage() {
           </div>
         </>}
 
+        {notifPrefs && <>
+          <div style={{ borderTop: "1px solid #e5e7eb", paddingTop: 20 }}>
+            <h3 style={{ fontSize: 16, fontWeight: 600, color: "#1f2937", marginBottom: 16 }}>
+              Notification Settings
+            </h3>
+
+            <div style={{ display: "flex", flexDirection: "column", gap: 12 }}>
+              <label style={{ display: "flex", alignItems: "center", gap: 10, fontSize: 14, color: "#374151", cursor: "pointer" }}>
+                <input
+                  type="checkbox"
+                  checked={notifPrefs.pace_notifications_enabled}
+                  onChange={(e) => setNotifPrefs({ ...notifPrefs, pace_notifications_enabled: e.target.checked })}
+                  style={{ width: 18, height: 18, cursor: "pointer" }}
+                />
+                Enable pace notifications
+              </label>
+
+              <label style={{ display: "flex", alignItems: "center", gap: 10, fontSize: 14, color: "#374151", cursor: "pointer" }}>
+                <input
+                  type="checkbox"
+                  checked={notifPrefs.reminder_enabled}
+                  onChange={(e) => setNotifPrefs({ ...notifPrefs, reminder_enabled: e.target.checked })}
+                  style={{ width: 18, height: 18, cursor: "pointer" }}
+                />
+                Enable pre-meeting reminders (24h before)
+              </label>
+
+              <div style={{ display: "flex", flexDirection: "column", gap: 8 }}>
+                <label style={{ fontSize: 14, fontWeight: 600, color: "#555" }}>Notification frequency</label>
+                <select
+                  value={notifPrefs.frequency}
+                  onChange={(e) => setNotifPrefs({ ...notifPrefs, frequency: e.target.value as NotificationPreferences["frequency"] })}
+                  style={{ padding: "10px 12px", borderRadius: 6, border: "1px solid #ddd", fontSize: 16, background: "#fff", outline: "none" }}
+                >
+                  <option value="daily">Daily</option>
+                  <option value="weekly">Weekly</option>
+                </select>
+              </div>
+            </div>
+          </div>
+        </>}
+
         <button onClick={handleSave} disabled={saving} style={{ padding: "12px 24px", borderRadius: 8, border: "none", background: "#1a1a2e", color: "#fff", fontSize: 16, fontWeight: 600, cursor: "pointer", opacity: saving ? 0.6 : 1, marginTop: 8 }}>{saving ? t("common.saving") : t("settings.saveSettings")}</button>
       </div>
     </SimpleFormPageLayout>

frontend/src/types/notifications.ts

@@ -0,0 +1,65 @@
+export interface PaceStatus {
+  meeting_id: number;
+  meeting_title: string;
+  scheduled_at: string;
+  target_section: number;
+  target_section_label: string;
+  current_section: number;
+  ahead_behind_delta: number;
+  status: "ahead" | "behind" | "on_track" | "completed";
+  days_until_meeting: number;
+  sections_to_catch_up: number;
+  ebook_id: number;
+  ebook_title: string;
+}
+
+export interface NotificationPreferences {
+  pace_notifications_enabled: boolean;
+  reminder_enabled: boolean;
+  frequency: "daily" | "weekly";
+}
+
+export interface MeetingReminder {
+  meeting_id: number;
+  meeting_title: string;
+  scheduled_at: string;
+  target_section: number;
+  target_section_label: string;
+  group_name: string;
+  hours_until: number;
+  ebook_id: number;
+  ebook_title: string;
+}
+
+export interface ReadingGroup {
+  id: number;
+  name: string;
+  description: string;
+  book: number | null;
+  ebook: number | null;
+  created_by: number;
+  created_at: string;
+  member_count: number;
+  meeting_count: number;
+}
+
+export interface GroupMeeting {
+  id: number;
+  group: number;
+  group_name: string;
+  title: string;
+  scheduled_at: string;
+  target_section: number;
+  target_section_label: string;
+  created_at: string;
+}
+
+export interface GroupMembership {
+  id: number;
+  user: number;
+  user_email: string;
+  group: number;
+  group_name: string;
+  role: "admin" | "member";
+  joined_at: string;
+}

packages/shared/src/types.ts

@@ -215,100 +215,4 @@ export interface PaginatedResponse<T> {
 export interface ApiError {
   detail?: string;
   [key: string]: unknown;
-}
-
-// ---- Groups ----
-
-export type GroupRole = "admin" | "member";
-
-export type JoinRequestStatus = "pending" | "approved" | "rejected";
-
-export interface GroupListItem {
-  id: number;
-  name: string;
-  description: string;
-  created_by: number;
-  member_count: number;
-  user_role: GroupRole | null;
-  created_at: string;
-  updated_at: string;
-}
-
-export interface GroupMember {
-  id: number;
-  user_id: number;
-  user_email: string;
-  user_username: string;
-  role: GroupRole;
-  joined_at: string;
-}
-
-export interface GroupDetail {
-  id: number;
-  name: string;
-  description: string;
-  created_by: number;
-  created_by_email: string;
-  created_by_username: string;
-  members: GroupMember[];
-  member_count: number;
-  user_role: GroupRole | null;
-  created_at: string;
-  updated_at: string;
-}
-
-export interface CreateGroupPayload {
-  name: string;
-  description?: string;
-}
-
-export interface UpdateGroupPayload {
-  name?: string;
-  description?: string;
-}
-
-export interface GroupInvite {
-  id: number;
-  group: number;
-  group_name: string;
-  code: string;
-  created_by: number;
-  created_by_email: string;
-  max_uses: number;
-  use_count: number;
-  is_active: boolean;
-  join_url: string;
-  created_at: string;
-}
-
-export interface CreateInvitePayload {
-  max_uses?: number;
-}
-
-export interface JoinRequest {
-  id: number;
-  group: number;
-  group_name: string;
-  user: number;
-  user_id: number;
-  user_email: string;
-  user_username: string;
-  invite: number | null;
-  invite_code: string | null;
-  status: JoinRequestStatus;
-  created_at: string;
-}
-
-export interface InviteValidation {
-  group: {
-    id: number;
-    name: string;
-    description: string;
-    created_by_email: string;
-    member_count: number;
-  };
-  invite: {
-    code: string;
-    created_by_email: string;
-  };
 }

packages/shared/src/utils.ts

@@ -114,18 +114,4 @@ export const API_ENDPOINTS = {
     bookmarkDetail: (id: string) => `/api/annotations/bookmarks/${id}/`,
     noteDetail: (id: string) => `/api/annotations/notes/${id}/`,
   },
-  groups: {
-    list: "/api/groups/",
-    detail: (id: number) => `/api/groups/${id}/`,
-    members: (id: number) => `/api/groups/${id}/members/`,
-    removeMember: (id: number, userId: number) => `/api/groups/${id}/members/${userId}/`,
-    updateRole: (id: number, userId: number) => `/api/groups/${id}/members/${userId}/role/`,
-    leave: (id: number) => `/api/groups/${id}/leave/`,
-    invites: (id: number) => `/api/groups/${id}/invites/`,
-    revokeInvite: (id: number, inviteId: number) => `/api/groups/${id}/invites/${inviteId}/`,
-    requests: (id: number) => `/api/groups/${id}/requests/`,
-    approveRequest: (id: number, requestId: number) => `/api/groups/${id}/requests/${requestId}/approve/`,
-    rejectRequest: (id: number, requestId: number) => `/api/groups/${id}/requests/${requestId}/reject/`,
-    join: (code: string) => `/api/join/${code}/`,
-  },
 } as const;