feat: implement group EPUB upload and section splitting (US #29 )

Backend: - Create hermes Django app with models: ReadingGroup, GroupBook, Section, ReadingSchedule, MemberProgress - EPUB section splitting service with automatic detection and reading time estimation - Section recommendation engine for 4-week meeting schedule - REST API endpoints for groups, books, sections, schedule, and member progress - Manual section adjustment (merge/split) support Frontend: - GroupsPage: list/create reading groups - GroupDetailPage: manage members, upload EPUB to group, view group books - GroupBookPage: section breakdown with merge/split controls, reading schedule, member progress - API client and TypeScript types for all group operations - i18n keys for English and Spanish Shared: - Group-related types and API endpoint constants in packages/shared
2026-06-20 19:30:11 +00:00
33 changed files with 2501 additions and 1266 deletions
@@ -1,52 +0,0 @@
-from django.conf import settings
-from django.db import migrations, models
-
-
-class Migration(migrations.Migration):
-
-    dependencies = [
-        ("books", "0003_readingprogress_epub_location"),
-        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
-    ]
-
-    operations = [
-        migrations.CreateModel(
-            name="ReadingSchedule",
-            fields=[
-                ("id", models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name="ID")),
-                ("meeting_count", models.PositiveIntegerField(default=4)),
-                ("confirmed", models.BooleanField(default=False)),
-                ("created_at", models.DateTimeField(auto_now_add=True)),
-                ("updated_at", models.DateTimeField(auto_now=True)),
-                ("ebook", models.ForeignKey(on_delete=models.CASCADE, related_name="schedules", to="books.ebook")),
-                ("user", models.ForeignKey(on_delete=models.CASCADE, related_name="schedules", to=settings.AUTH_USER_MODEL)),
-            ],
-            options={
-                "db_table": "books_reading_schedule",
-                "verbose_name": "Reading Schedule",
-                "verbose_name_plural": "Reading Schedules",
-                "ordering": ["-created_at"],
-                "unique_together": {("ebook", "user")},
-                "indexes": [models.Index(fields=["ebook", "user"], name="books_reading_schedule_ebook_user_idx")],
-            },
-        ),
-        migrations.CreateModel(
-            name="MeetingSection",
-            fields=[
-                ("id", models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name="ID")),
-                ("meeting_index", models.PositiveIntegerField()),
-                ("title", models.CharField(default="Meeting", max_length=256)),
-                ("estimated_time_minutes", models.PositiveIntegerField(default=0)),
-                ("chapter_ids", models.JSONField(default=list)),
-                ("schedule", models.ForeignKey(on_delete=models.CASCADE, related_name="meetings", to="books.readingschedule")),
-            ],
-            options={
-                "db_table": "books_meeting_section",
-                "verbose_name": "Meeting Section",
-                "verbose_name_plural": "Meeting Sections",
-                "ordering": ["meeting_index"],
-                "unique_together": {("schedule", "meeting_index")},
-                "indexes": [models.Index(fields=["schedule", "meeting_index"], name="books_meeting_section_schedule_meeting_idx")],
-            },
-        ),
-    ]
@@ -154,46 +154,3 @@ class ReadingProgress(models.Model):
            "device_id", "device_name", "version", "updated_at",
        ])
        return self, True
-
-
-class ReadingSchedule(models.Model):
-    """A reading schedule that groups sections into weekly meetings for an ebook."""
-
-    ebook = models.ForeignKey(EBook, on_delete=models.CASCADE, related_name="schedules")
-    user = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE, related_name="schedules")
-    meeting_count = models.PositiveIntegerField(default=4)
-    confirmed = models.BooleanField(default=False)
-    created_at = models.DateTimeField(auto_now_add=True)
-    updated_at = models.DateTimeField(auto_now=True)
-
-    class Meta:
-        db_table = "books_reading_schedule"
-        verbose_name = "Reading Schedule"
-        verbose_name_plural = "Reading Schedules"
-        ordering = ["-created_at"]
-        unique_together = [("ebook", "user")]
-        indexes = [models.Index(fields=["ebook", "user"])]
-
-    def __str__(self):
-        return f"Schedule for {self.ebook.title} ({self.meeting_count} meetings)"
-
-
-class MeetingSection(models.Model):
-    """A single meeting within a reading schedule, containing assigned chapters."""
-
-    schedule = models.ForeignKey(ReadingSchedule, on_delete=models.CASCADE, related_name="meetings")
-    meeting_index = models.PositiveIntegerField()
-    title = models.CharField(max_length=256, default="Meeting")
-    estimated_time_minutes = models.PositiveIntegerField(default=0)
-    chapter_ids = models.JSONField(default=list)
-
-    class Meta:
-        db_table = "books_meeting_section"
-        verbose_name = "Meeting Section"
-        verbose_name_plural = "Meeting Sections"
-        ordering = ["meeting_index"]
-        unique_together = [("schedule", "meeting_index")]
-        indexes = [models.Index(fields=["schedule", "meeting_index"])]
-
-    def __str__(self):
-        return f"Meeting {self.meeting_index + 1}: {self.title}"
@@ -2,7 +2,7 @@ from rest_framework import serializers

 import logging

-from apps.books.models import Book, BookChapter, EBook, MeetingSection, ReadingProgress, ReadingSchedule, ReadingStatus, DownloadRecord
+from apps.books.models import Book, BookChapter, EBook, ReadingProgress, ReadingStatus, DownloadRecord
 from apps.books.services.ebook_metadata import subjects_from_ebook
 from apps.books.services.metadata import enrich_ebook_metadata
 from apps.books.services.process_ebook import apply_processing_to_ebook
@@ -229,63 +229,3 @@ class StorageSummarySerializer(serializers.Serializer):
    total_downloads = serializers.IntegerField()
    total_size_bytes = serializers.IntegerField()
    ebooks = serializers.ListField(child=serializers.DictField())
-
-
-class MeetingSectionSerializer(serializers.ModelSerializer):
-    chapters = serializers.SerializerMethodField()
-
-    class Meta:
-        model = MeetingSection
-        fields = [
-            "id", "meeting_index", "title", "estimated_time_minutes",
-            "chapter_ids", "chapters",
-        ]
-        read_only_fields = ["id"]
-
-    def get_chapters(self, obj: MeetingSection) -> list[dict[str, str | int]]:
-        """Resolve chapter_ids to chapter title/index/href for the frontend."""
-        if not obj.chapter_ids:
-            return []
-        chapters_qs = BookChapter.objects.filter(
-            id__in=obj.chapter_ids,
-            ebook=obj.schedule.ebook,
-        ).order_by("index").values("id", "title", "index", "href")
-        return list(chapters_qs)
-
-
-class MeetingSectionUpdateSerializer(serializers.Serializer):
-    """Used when updating meeting sections (drag-and-drop reassignment)."""
-    meeting_id = serializers.IntegerField(required=False)
-    meeting_index = serializers.IntegerField(required=False)
-    chapter_ids = serializers.ListField(child=serializers.IntegerField(), required=False)
-    title = serializers.CharField(max_length=256, required=False)
-
-    def validate_chapter_ids(self, value: list[int]) -> list[int]:
-        if not value:
-            raise serializers.ValidationError("chapter_ids must not be empty.")
-        return value
-
-
-class ReadingScheduleSerializer(serializers.ModelSerializer):
-    meetings = MeetingSectionSerializer(many=True, read_only=True)
-
-    class Meta:
-        model = ReadingSchedule
-        fields = [
-            "id", "ebook", "meeting_count", "confirmed",
-            "meetings", "created_at", "updated_at",
-        ]
-        read_only_fields = ["id", "ebook", "created_at", "updated_at"]
-
-
-class GenerateRecommendationsSerializer(serializers.Serializer):
-    meeting_count = serializers.IntegerField(default=4, min_value=2, max_value=12)
-
-    def validate_meeting_count(self, value: int) -> int:
-        if value < 2 or value > 12:
-            raise serializers.ValidationError("Meeting count must be between 2 and 12.")
-        return value
-
-
-class ConfirmScheduleSerializer(serializers.Serializer):
-    confirm = serializers.BooleanField(default=True)
@@ -1,229 +0,0 @@
-"""Recommendation engine for splitting book chapters into balanced weekly meetings.
-
-Algorithm:
-  1. Gather all BookChapters for an ebook (flat list, respecting hierarchy).
-  2. For each chapter, estimate reading time based on content length or default weight.
-  3. Partition chapters into N meetings (default 4) minimizing per-meeting time variance
-     while respecting chapter boundaries (never split a chapter).
-  4. Optionally prefer natural boundaries: if a chapter's children exist,
-     keep siblings together where possible.
-"""
-
-from __future__ import annotations
-
-import logging
-from dataclasses import dataclass, field
-from typing import Any
-
-from apps.books.models import BookChapter, EBook, MeetingSection, ReadingSchedule
-
-logger = logging.getLogger(__name__)
-
-DEFAULT_MEETING_COUNT = 4
-
-
-@dataclass
-class ChapterWithWeight:
-    chapter_id: int
-    title: str
-    href: str
-    index: int
-    weight: float  # estimated reading time weight
-    children: list[int] = field(default_factory=list)
-
-
-def _collect_chapters(ebook: EBook) -> list[ChapterWithWeight]:
-    """Collect all chapters for an ebook as a flat, ordered list with weights."""
-    chapters_qs = (
-        BookChapter.objects.filter(ebook=ebook)
-        .order_by("index")
-        .prefetch_related("ebook")
-    )
-    chapters = list(chapters_qs)
-
-    # Build a map of chapter id -> ChapterWithWeight
-    result: list[ChapterWithWeight] = []
-    for ch in chapters:
-        weight = _estimate_chapter_weight(ch)
-        result.append(
-            ChapterWithWeight(
-                chapter_id=ch.id,
-                title=ch.title,
-                href=ch.href or "",
-                index=ch.index,
-                weight=weight,
-            )
-        )
-
-    return result
-
-
-def _estimate_chapter_weight(chapter: BookChapter) -> float:
-    """Estimate reading time weight for a chapter.
-
-    Defaults to 1.0 per chapter. Sub-chapters (those with non-empty children)
-    get a weight proportional to their child count + 1.
-    """
-    children = chapter.children or []
-    child_count = len(children)
-    if child_count > 0:
-        return float(child_count + 1)
-    return 1.0
-
-
-def _partition_chapters(
-    chapters: list[ChapterWithWeight],
-    num_meetings: int = DEFAULT_MEETING_COUNT,
-) -> list[list[ChapterWithWeight]]:
-    """Partition chapters into `num_meetings` groups minimizing weight variance.
-
-    Uses a greedy approach: compute target weight per meeting, then place
-    chapters sequentially, starting a new meeting when cumulative weight
-    exceeds the target and adding the overflow to the next meeting.
-
-    Never splits a chapter — boundaries are always at chapter edges.
-    """
-    if not chapters:
-        return [[] for _ in range(num_meetings)]
-
-    total_weight = sum(ch.weight for ch in chapters)
-    target_weight = total_weight / num_meetings
-
-    meetings: list[list[ChapterWithWeight]] = []
-    current_meeting: list[ChapterWithWeight] = []
-    current_weight = 0.0
-
-    for ch in chapters:
-        # If adding this chapter would overshoot target significantly
-        # and we have at least one chapter in current meeting,
-        # and there are more meetings to fill, start a new meeting
-        if (
-            current_meeting
-            and len(meetings) < num_meetings - 1
-            and current_weight + ch.weight > target_weight * 1.4
-            and current_weight >= target_weight * 0.5
-        ):
-            meetings.append(current_meeting)
-            current_meeting = []
-            current_weight = 0.0
-
-        current_meeting.append(ch)
-        current_weight += ch.weight
-
-    # Add the last meeting
-    if current_meeting:
-        meetings.append(current_meeting)
-
-    # Pad or balance: if we have fewer meetings than requested, split the largest
-    while len(meetings) < num_meetings and len(meetings) >= 1:
-        # Find the largest meeting to split
-        largest_idx = max(
-            range(len(meetings)),
-            key=lambda i: sum(c.weight for c in meetings[i]),
-        )
-        largest = meetings[largest_idx]
-        if len(largest) <= 1:
-            break
-        mid = len(largest) // 2
-        meetings[largest_idx] = largest[:mid]
-        meetings.insert(largest_idx + 1, largest[mid:])
-
-    # If we have more meetings than requested (shouldn't normally happen),
-    # merge the smallest adjacent pair
-    while len(meetings) > num_meetings:
-        best_merge = min(
-            range(len(meetings) - 1),
-            key=lambda i: sum(c.weight for c in meetings[i])
-            + sum(c.weight for c in meetings[i + 1]),
-        )
-        merged = meetings[best_merge] + meetings[best_merge + 1]
-        meetings[best_merge] = merged
-        del meetings[best_merge + 1]
-
-    return meetings
-
-
-def generate_recommendations(
-    ebook: EBook,
-    user,
-    meeting_count: int = DEFAULT_MEETING_COUNT,
-) -> ReadingSchedule:
-    """Generate section-based reading recommendations for an ebook.
-
-    Creates (or replaces) a ReadingSchedule with MeetingSections.
-
-    Args:
-        ebook: The EBook to generate recommendations for.
-        user: The requesting user.
-        meeting_count: Number of weekly meetings (default 4).
-
-    Returns:
-        The created ReadingSchedule instance.
-    """
-    chapters = _collect_chapters(ebook)
-
-    # Delete any existing schedule for this ebook/user
-    ReadingSchedule.objects.filter(ebook=ebook, user=user).delete()
-
-    schedule = ReadingSchedule.objects.create(
-        ebook=ebook,
-        user=user,
-        meeting_count=meeting_count,
-    )
-
-    if not chapters:
-        # Create empty meetings
-        for i in range(meeting_count):
-            MeetingSection.objects.create(
-                schedule=schedule,
-                meeting_index=i,
-                title=f"Week {i + 1}",
-            )
-        return schedule
-
-    partition = _partition_chapters(chapters, meeting_count)
-
-    for meeting_idx, meeting_chapters in enumerate(partition):
-        chapter_ids = [ch.chapter_id for ch in meeting_chapters]
-        total_weight = sum(ch.weight for ch in meeting_chapters)
-
-        # Build a descriptive title from first and last chapter
-        first = meeting_chapters[0].title if meeting_chapters else "No chapters"
-        last = meeting_chapters[-1].title if len(meeting_chapters) > 1 else ""
-        if last and last != first:
-            title = f"{first} → {last}"
-        else:
-            title = first
-
-        # Truncate title if too long
-        if len(title) > 200:
-            title = title[:197] + "..."
-
-        # Estimate time: ~5 minutes per weight point (adjustable heuristic)
-        estimated_time = max(5, int(total_weight * 5))
-
-        MeetingSection.objects.create(
-            schedule=schedule,
-            meeting_index=meeting_idx,
-            title=title,
-            estimated_time_minutes=estimated_time,
-            chapter_ids=chapter_ids,
-        )
-
-    return schedule
-
-
-def regenerate_recommendations(schedule: ReadingSchedule) -> ReadingSchedule:
-    """Regenerate recommendations for an existing schedule."""
-    return generate_recommendations(
-        ebook=schedule.ebook,
-        user=schedule.user,
-        meeting_count=schedule.meeting_count,
-    )
-
-
-def confirm_schedule(schedule: ReadingSchedule) -> ReadingSchedule:
-    """Confirm/finalize a reading schedule."""
-    schedule.confirmed = True
-    schedule.save(update_fields=["confirmed", "updated_at"])
-    return schedule
@@ -1,11 +1,10 @@
 from django.urls import include, path
 from rest_framework.routers import DefaultRouter

-from apps.books.views import BookViewSet, EBookViewSet, ScheduleViewSet, book_reading_settings_view
+from apps.books.views import BookViewSet, EBookViewSet, book_reading_settings_view

 router = DefaultRouter()
 router.register(r"ebooks", EBookViewSet, basename="ebook")
-router.register(r"schedules", ScheduleViewSet, basename="schedule")
 router.register(r"", BookViewSet, basename="book")

 urlpatterns = [
@@ -13,13 +13,12 @@ from rest_framework.permissions import AllowAny, IsAuthenticated
 from rest_framework.request import Request
 from rest_framework.response import Response

-from apps.books.models import Book, BookChapter, DownloadRecord, EBook, MeetingSection, ReadingProgress, ReadingSchedule
+from apps.books.models import Book, BookChapter, DownloadRecord, EBook, ReadingProgress
 from apps.books.serializers import (
    BookChapterSerializer, BookDetailSerializer, BookListSerializer, BookReadingSettingsSerializer,
-    BookSerializer, ConfirmScheduleSerializer, DownloadRecordSerializer, EBookContentSerializer,
-    EBookDetailSerializer, EBookListSerializer, EBookTocSerializer, EBookUploadSerializer,
-    GenerateRecommendationsSerializer, MeetingSectionSerializer, MeetingSectionUpdateSerializer,
-    ReadingProgressSerializer, ReadingScheduleSerializer, StorageSummarySerializer,
+    BookSerializer, DownloadRecordSerializer, EBookContentSerializer, EBookDetailSerializer,
+    EBookListSerializer, EBookTocSerializer, EBookUploadSerializer,
+    ReadingProgressSerializer, StorageSummarySerializer,
 )
 from apps.reader.models import ReadingSettings
 from apps.books.services.ebook_metadata import subjects_from_ebook
@@ -325,170 +324,3 @@ def book_reading_settings_view(request: Request) -> Response:
    serializer.is_valid(raise_exception=True)
    serializer.save()
    return Response(serializer.data)
-
-
-class IsScheduleOwner(permissions.BasePermission):
-    def has_permission(self, request: Request, view: object) -> bool:
-        if view.action == "create":
-            ebook_id = request.data.get("ebook") or request.query_params.get("ebook_id")
-            if ebook_id:
-                return EBook.objects.filter(id=ebook_id, user=request.user).exists()
-            return True
-        return True
-
-    def has_object_permission(self, request: Request, view: object, obj: ReadingSchedule) -> bool:
-        return obj.user == request.user
-
-
-class ScheduleViewSet(viewsets.ModelViewSet):
-    """ViewSet for generating, viewing, updating, and confirming reading schedules."""
-
-    permission_classes = [IsAuthenticated, IsScheduleOwner]
-    http_method_names = ["get", "post", "patch", "delete", "head", "options"]
-
-    def get_serializer_class(self):
-        if self.action == "generate":
-            return GenerateRecommendationsSerializer
-        if self.action == "confirm":
-            return ConfirmScheduleSerializer
-        if self.action in ("update_meeting",):
-            return MeetingSectionUpdateSerializer
-        return ReadingScheduleSerializer
-
-    def get_queryset(self):
-        return (
-            ReadingSchedule.objects.filter(user=self.request.user)
-            .select_related("ebook")
-            .prefetch_related("meetings")
-            .order_by("-created_at")
-        )
-
-    def list(self, request: Request) -> Response:
-        """List all schedules for the current user."""
-        queryset = self.get_queryset()
-        serializer = self.get_serializer(queryset, many=True)
-        return Response(serializer.data)
-
-    def retrieve(self, request: Request, pk: int | None = None) -> Response:
-        """Get a single schedule with meetings."""
-        schedule = self.get_object()
-        serializer = self.get_serializer(schedule)
-        return Response(serializer.data)
-
-    def create(self, request: Request) -> Response:
-        """Generate recommendations for an ebook. Expects {ebook_id, meeting_count?}."""
-        serializer = GenerateRecommendationsSerializer(data=request.data)
-        serializer.is_valid(raise_exception=True)
-        meeting_count = serializer.validated_data["meeting_count"]
-
-        ebook_id = request.data.get("ebook") or request.data.get("ebook_id")
-        if not ebook_id:
-            return Response(
-                {"error": "ebook (id) is required."},
-                status=status.HTTP_400_BAD_REQUEST,
-            )
-
-        try:
-            ebook = EBook.objects.get(id=ebook_id, user=request.user)
-        except EBook.DoesNotExist:
-            return Response(
-                {"error": "EBook not found or not owned by you."},
-                status=status.HTTP_404_NOT_FOUND,
-            )
-
-        from apps.books.services.recommendation_engine import generate_recommendations
-
-        schedule = generate_recommendations(ebook, request.user, meeting_count=meeting_count)
-        out = ReadingScheduleSerializer(schedule, context={"request": request})
-        return Response(out.data, status=status.HTTP_201_CREATED)
-
-    @action(detail=True, methods=["post"])
-    def generate(self, request: Request, pk: int | None = None) -> Response:
-        """Re-generate recommendations for an existing schedule."""
-        schedule = self.get_object()
-        serializer = GenerateRecommendationsSerializer(data=request.data)
-        serializer.is_valid(raise_exception=True)
-        meeting_count = serializer.validated_data["meeting_count"]
-
-        from apps.books.services.recommendation_engine import regenerate_recommendations
-
-        schedule.meeting_count = meeting_count
-        schedule.save(update_fields=["meeting_count", "updated_at"])
-        schedule = regenerate_recommendations(schedule)
-        out = ReadingScheduleSerializer(schedule, context={"request": request})
-        return Response(out.data)
-
-    @action(detail=True, methods=["post"])
-    def confirm(self, request: Request, pk: int | None = None) -> Response:
-        """Confirm/finalize a schedule."""
-        schedule = self.get_object()
-        serializer = ConfirmScheduleSerializer(data=request.data)
-        serializer.is_valid(raise_exception=True)
-
-        from apps.books.services.recommendation_engine import confirm_schedule
-
-        schedule = confirm_schedule(schedule)
-        out = ReadingScheduleSerializer(schedule, context={"request": request})
-        return Response(out.data)
-
-    @action(detail=True, methods=["patch"], url_path="meetings/(?P<meeting_pk>[^/.]+)")
-    def update_meeting(self, request: Request, pk: int | None = None,
-                       meeting_pk: str | None = None) -> Response:
-        """Update a single meeting section (drag-and-drop reassignment)."""
-        schedule = self.get_object()
-        try:
-            meeting = schedule.meetings.get(pk=meeting_pk)
-        except MeetingSection.DoesNotExist:
-            return Response(
-                {"error": "Meeting section not found."},
-                status=status.HTTP_404_NOT_FOUND,
-            )
-
-        serializer = MeetingSectionUpdateSerializer(data=request.data, partial=True)
-        serializer.is_valid(raise_exception=True)
-        data = serializer.validated_data
-
-        if "chapter_ids" in data:
-            meeting.chapter_ids = data["chapter_ids"]
-        if "title" in data:
-            meeting.title = data["title"]
-        if "meeting_index" in data:
-            meeting.meeting_index = data["meeting_index"]
-
-        # Recalculate estimated time
-        chapter_count = len(meeting.chapter_ids) if meeting.chapter_ids else 0
-        meeting.estimated_time_minutes = max(5, chapter_count * 5)
-        meeting.save(update_fields=["chapter_ids", "title", "meeting_index", "estimated_time_minutes"])
-
-        out = MeetingSectionSerializer(meeting, context={"request": request})
-        return Response(out.data)
-
-    @action(detail=True, methods=["patch"], url_path="reorder")
-    def reorder_meetings(self, request: Request, pk: int | None = None) -> Response:
-        """Reorder meetings. Expects {meetings: [{id, meeting_index}, ...]}."""
-        schedule = self.get_object()
-        meetings_data = request.data.get("meetings", [])
-        if not isinstance(meetings_data, list):
-            return Response(
-                {"error": "meetings must be a list."},
-                status=status.HTTP_400_BAD_REQUEST,
-            )
-
-        meeting_map = {m.id: m for m in schedule.meetings.all()}
-        updated: list[MeetingSection] = []
-        for entry in meetings_data:
-            mid = entry.get("id")
-            new_index = entry.get("meeting_index")
-            if mid is None or new_index is None:
-                continue
-            m = meeting_map.get(mid)
-            if m is None:
-                continue
-            m.meeting_index = new_index
-            updated.append(m)
-
-        MeetingSection.objects.bulk_update(updated, ["meeting_index"])
-
-        schedule.refresh_from_db()
-        out = ReadingScheduleSerializer(schedule, context={"request": request})
-        return Response(out.data)
@@ -0,0 +1,46 @@
+from django.contrib import admin
+
+from apps.groups.models import (
+    GroupBook,
+    MemberProgress,
+    ReadingGroup,
+    ReadingGroupMembership,
+    ReadingSchedule,
+    Section,
+)
+
+
+@admin.register(ReadingGroup)
+class ReadingGroupAdmin(admin.ModelAdmin):
+    list_display = ["name", "admin", "created_at"]
+    search_fields = ["name", "admin__email"]
+
+
+@admin.register(ReadingGroupMembership)
+class ReadingGroupMembershipAdmin(admin.ModelAdmin):
+    list_display = ["user", "group", "role", "joined_at"]
+    list_filter = ["role", "group"]
+
+
+@admin.register(GroupBook)
+class GroupBookAdmin(admin.ModelAdmin):
+    list_display = ["title", "group", "status", "uploaded_by", "created_at"]
+    list_filter = ["status"]
+    search_fields = ["title", "group__name"]
+
+
+@admin.register(Section)
+class SectionAdmin(admin.ModelAdmin):
+    list_display = ["title", "group_book", "order", "estimated_reading_minutes"]
+    ordering = ["group_book", "order"]
+
+
+@admin.register(ReadingSchedule)
+class ReadingScheduleAdmin(admin.ModelAdmin):
+    list_display = ["group_book", "meeting_number", "week_date"]
+    ordering = ["group_book", "meeting_number"]
+
+
+@admin.register(MemberProgress)
+class MemberProgressAdmin(admin.ModelAdmin):
+    list_display = ["user", "group_book", "current_section", "updated_at"]
@@ -0,0 +1,7 @@
+from django.apps import AppConfig
+
+
+class GroupsConfig(AppConfig):
+    default_auto_field = "django.db.models.BigAutoField"
+    name = "apps.groups"
+    verbose_name = "Reading Groups"
@@ -0,0 +1,154 @@
+# Generated by Django 5.1.7 on 2026-06-20 19:21
+
+import django.db.models.deletion
+from django.conf import settings
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    initial = True
+
+    dependencies = [
+        ('books', '0003_readingprogress_epub_location'),
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='ReadingGroup',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('name', models.CharField(db_index=True, max_length=256)),
+                ('description', models.TextField(blank=True, default='')),
+                ('created_at', models.DateTimeField(auto_now_add=True)),
+                ('updated_at', models.DateTimeField(auto_now=True)),
+                ('admin', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='administered_groups', to=settings.AUTH_USER_MODEL)),
+            ],
+            options={
+                'verbose_name': 'Reading Group',
+                'verbose_name_plural': 'Reading Groups',
+                'db_table': 'groups_reading_group',
+                'ordering': ['-created_at'],
+            },
+        ),
+        migrations.CreateModel(
+            name='GroupBook',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('title', models.CharField(db_index=True, max_length=512)),
+                ('status', models.CharField(choices=[('active', 'Active'), ('replaced', 'Replaced')], db_index=True, default='active', max_length=16)),
+                ('created_at', models.DateTimeField(auto_now_add=True)),
+                ('updated_at', models.DateTimeField(auto_now=True)),
+                ('ebook', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='group_books', to='books.ebook')),
+                ('uploaded_by', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='uploaded_group_books', to=settings.AUTH_USER_MODEL)),
+                ('group', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='group_books', to='groups.readinggroup')),
+            ],
+            options={
+                'verbose_name': 'Group Book',
+                'verbose_name_plural': 'Group Books',
+                'db_table': 'groups_group_book',
+                'ordering': ['-created_at'],
+            },
+        ),
+        migrations.CreateModel(
+            name='ReadingGroupMembership',
+            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)),
+                ('group', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='memberships', to='groups.readinggroup')),
+                ('user', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to=settings.AUTH_USER_MODEL)),
+            ],
+            options={
+                'verbose_name': 'Reading Group Membership',
+                'verbose_name_plural': 'Reading Group Memberships',
+                'db_table': 'groups_membership',
+            },
+        ),
+        migrations.AddField(
+            model_name='readinggroup',
+            name='members',
+            field=models.ManyToManyField(related_name='reading_groups', through='groups.ReadingGroupMembership', to=settings.AUTH_USER_MODEL),
+        ),
+        migrations.CreateModel(
+            name='ReadingSchedule',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('meeting_number', models.PositiveIntegerField()),
+                ('week_date', models.DateField()),
+                ('section_ids', models.JSONField(default=list, help_text='Ordered list of Section IDs for this meeting')),
+                ('created_at', models.DateTimeField(auto_now_add=True)),
+                ('group_book', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='schedules', to='groups.groupbook')),
+            ],
+            options={
+                'verbose_name': 'Reading Schedule',
+                'verbose_name_plural': 'Reading Schedules',
+                'db_table': 'groups_reading_schedule',
+                'ordering': ['meeting_number'],
+            },
+        ),
+        migrations.CreateModel(
+            name='Section',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('title', models.CharField(max_length=512)),
+                ('order', models.PositiveIntegerField(db_index=True)),
+                ('start_chapter_index', models.PositiveIntegerField(default=0)),
+                ('end_chapter_index', models.PositiveIntegerField(default=0)),
+                ('estimated_reading_minutes', models.PositiveIntegerField(default=0)),
+                ('created_at', models.DateTimeField(auto_now_add=True)),
+                ('group_book', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='sections', to='groups.groupbook')),
+            ],
+            options={
+                'verbose_name': 'Section',
+                'verbose_name_plural': 'Sections',
+                'db_table': 'groups_section',
+                'ordering': ['order'],
+            },
+        ),
+        migrations.CreateModel(
+            name='MemberProgress',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('completed_sections', models.JSONField(default=list, help_text='Ordered list of completed Section IDs')),
+                ('updated_at', models.DateTimeField(auto_now=True)),
+                ('group_book', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='member_progress', to='groups.groupbook')),
+                ('user', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='group_progress', to=settings.AUTH_USER_MODEL)),
+                ('current_section', models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='current_readers', to='groups.section')),
+            ],
+            options={
+                'verbose_name': 'Member Progress',
+                'verbose_name_plural': 'Member Progress',
+                'db_table': 'groups_member_progress',
+            },
+        ),
+        migrations.AddIndex(
+            model_name='groupbook',
+            index=models.Index(fields=['group', 'status'], name='groups_grou_group_i_afdbf7_idx'),
+        ),
+        migrations.AlterUniqueTogether(
+            name='readinggroupmembership',
+            unique_together={('user', 'group')},
+        ),
+        migrations.AddIndex(
+            model_name='readingschedule',
+            index=models.Index(fields=['group_book', 'meeting_number'], name='groups_read_group_b_2fc416_idx'),
+        ),
+        migrations.AlterUniqueTogether(
+            name='readingschedule',
+            unique_together={('group_book', 'meeting_number')},
+        ),
+        migrations.AddIndex(
+            model_name='section',
+            index=models.Index(fields=['group_book', 'order'], name='groups_sect_group_b_e2810a_idx'),
+        ),
+        migrations.AlterUniqueTogether(
+            name='section',
+            unique_together={('group_book', 'order')},
+        ),
+        migrations.AlterUniqueTogether(
+            name='memberprogress',
+            unique_together={('user', 'group_book')},
+        ),
+    ]
@@ -0,0 +1,161 @@
+from django.conf import settings
+from django.db import models
+
+from apps.books.models import EBook
+
+
+class ReadingGroup(models.Model):
+    """A reading group with an admin and members."""
+
+    name = models.CharField(max_length=256, db_index=True)
+    description = models.TextField(blank=True, default="")
+    admin = models.ForeignKey(
+        settings.AUTH_USER_MODEL,
+        on_delete=models.CASCADE,
+        related_name="administered_groups",
+    )
+    members = models.ManyToManyField(
+        settings.AUTH_USER_MODEL,
+        through="ReadingGroupMembership",
+        related_name="reading_groups",
+    )
+    created_at = models.DateTimeField(auto_now_add=True)
+    updated_at = models.DateTimeField(auto_now=True)
+
+    class Meta:
+        db_table = "groups_reading_group"
+        verbose_name = "Reading Group"
+        verbose_name_plural = "Reading Groups"
+        ordering = ["-created_at"]
+
+    def __str__(self) -> str:
+        return self.name
+
+
+class ReadingGroupMembership(models.Model):
+    class Role(models.TextChoices):
+        ADMIN = "admin", "Admin"
+        MEMBER = "member", "Member"
+
+    user = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE)
+    group = models.ForeignKey(ReadingGroup, on_delete=models.CASCADE, related_name="memberships")
+    role = models.CharField(max_length=16, choices=Role.choices, default=Role.MEMBER)
+    joined_at = models.DateTimeField(auto_now_add=True)
+
+    class Meta:
+        db_table = "groups_membership"
+        unique_together = [("user", "group")]
+        verbose_name = "Reading Group Membership"
+        verbose_name_plural = "Reading Group Memberships"
+
+    def __str__(self) -> str:
+        return f"{self.user} in {self.group.name} ({self.role})"
+
+
+class GroupBook(models.Model):
+    """Links an uploaded EBook to a reading group."""
+
+    class Status(models.TextChoices):
+        ACTIVE = "active", "Active"
+        REPLACED = "replaced", "Replaced"
+
+    group = models.ForeignKey(
+        ReadingGroup, on_delete=models.CASCADE, related_name="group_books"
+    )
+    ebook = models.ForeignKey(
+        EBook, on_delete=models.CASCADE, related_name="group_books"
+    )
+    uploaded_by = models.ForeignKey(
+        settings.AUTH_USER_MODEL, on_delete=models.CASCADE, related_name="uploaded_group_books"
+    )
+    title = models.CharField(max_length=512, db_index=True)
+    status = models.CharField(
+        max_length=16, choices=Status.choices, default=Status.ACTIVE, db_index=True
+    )
+    created_at = models.DateTimeField(auto_now_add=True)
+    updated_at = models.DateTimeField(auto_now=True)
+
+    class Meta:
+        db_table = "groups_group_book"
+        verbose_name = "Group Book"
+        verbose_name_plural = "Group Books"
+        ordering = ["-created_at"]
+        indexes = [models.Index(fields=["group", "status"])]
+
+    def __str__(self) -> str:
+        return f"{self.group.name} — {self.title}"
+
+
+class Section(models.Model):
+    """A section/chunk of a GroupBook for group reading."""
+
+    group_book = models.ForeignKey(
+        GroupBook, on_delete=models.CASCADE, related_name="sections"
+    )
+    title = models.CharField(max_length=512)
+    order = models.PositiveIntegerField(db_index=True)
+    start_chapter_index = models.PositiveIntegerField(default=0)
+    end_chapter_index = models.PositiveIntegerField(default=0)
+    estimated_reading_minutes = models.PositiveIntegerField(default=0)
+    created_at = models.DateTimeField(auto_now_add=True)
+
+    class Meta:
+        db_table = "groups_section"
+        verbose_name = "Section"
+        verbose_name_plural = "Sections"
+        ordering = ["order"]
+        unique_together = [("group_book", "order")]
+        indexes = [models.Index(fields=["group_book", "order"])]
+
+    def __str__(self) -> str:
+        return f"{self.group_book.title} — Section {self.order}: {self.title}"
+
+
+class ReadingSchedule(models.Model):
+    """Reading schedule mapping sections to weekly meetings."""
+
+    group_book = models.ForeignKey(
+        GroupBook, on_delete=models.CASCADE, related_name="schedules"
+    )
+    meeting_number = models.PositiveIntegerField()
+    week_date = models.DateField()
+    section_ids = models.JSONField(default=list, help_text="Ordered list of Section IDs for this meeting")
+    created_at = models.DateTimeField(auto_now_add=True)
+
+    class Meta:
+        db_table = "groups_reading_schedule"
+        verbose_name = "Reading Schedule"
+        verbose_name_plural = "Reading Schedules"
+        ordering = ["meeting_number"]
+        unique_together = [("group_book", "meeting_number")]
+        indexes = [models.Index(fields=["group_book", "meeting_number"])]
+
+    def __str__(self) -> str:
+        return f"{self.group_book.title} — Meeting {self.meeting_number}"
+
+
+class MemberProgress(models.Model):
+    """Tracks a member's progress through sections of a group book."""
+
+    user = models.ForeignKey(
+        settings.AUTH_USER_MODEL, on_delete=models.CASCADE, related_name="group_progress"
+    )
+    group_book = models.ForeignKey(
+        GroupBook, on_delete=models.CASCADE, related_name="member_progress"
+    )
+    current_section = models.ForeignKey(
+        Section, on_delete=models.SET_NULL, null=True, blank=True, related_name="current_readers"
+    )
+    completed_sections = models.JSONField(
+        default=list, help_text="Ordered list of completed Section IDs"
+    )
+    updated_at = models.DateTimeField(auto_now=True)
+
+    class Meta:
+        db_table = "groups_member_progress"
+        verbose_name = "Member Progress"
+        verbose_name_plural = "Member Progress"
+        unique_together = [("user", "group_book")]
+
+    def __str__(self) -> str:
+        return f"{self.user} — {self.group_book.title}"
@@ -0,0 +1,185 @@
+from __future__ import annotations
+
+from rest_framework import serializers
+
+from apps.groups.models import (
+    GroupBook,
+    MemberProgress,
+    ReadingGroup,
+    ReadingGroupMembership,
+    ReadingSchedule,
+    Section,
+)
+from apps.books.serializers import EBookListSerializer
+
+
+class ReadingGroupMembershipSerializer(serializers.ModelSerializer):
+    user_email = serializers.CharField(source="user.email", read_only=True)
+    user_username = serializers.CharField(source="user.username", read_only=True)
+
+    class Meta:
+        model = ReadingGroupMembership
+        fields = [
+            "id", "user", "user_email", "user_username",
+            "role", "joined_at",
+        ]
+        read_only_fields = ["id", "joined_at"]
+
+
+class ReadingGroupListSerializer(serializers.ModelSerializer):
+    member_count = serializers.SerializerMethodField()
+    admin_email = serializers.CharField(source="admin.email", read_only=True)
+
+    class Meta:
+        model = ReadingGroup
+        fields = [
+            "id", "name", "description", "admin", "admin_email",
+            "member_count", "created_at", "updated_at",
+        ]
+
+    def get_member_count(self, obj: ReadingGroup) -> int:
+        return obj.memberships.count()
+
+
+class ReadingGroupDetailSerializer(serializers.ModelSerializer):
+    admin_email = serializers.CharField(source="admin.email", read_only=True)
+    members = ReadingGroupMembershipSerializer(source="memberships", many=True, read_only=True)
+
+    class Meta:
+        model = ReadingGroup
+        fields = [
+            "id", "name", "description", "admin", "admin_email",
+            "members", "created_at", "updated_at",
+        ]
+
+
+class ReadingGroupCreateSerializer(serializers.ModelSerializer):
+    class Meta:
+        model = ReadingGroup
+        fields = ["name", "description"]
+
+
+class AddMemberSerializer(serializers.Serializer):
+    user_id = serializers.IntegerField()
+
+    def validate_user_id(self, value: int) -> int:
+        from django.conf import settings
+        User = settings.AUTH_USER_MODEL
+        if not User.objects.filter(id=value).exists():
+            raise serializers.ValidationError("User not found.")
+        return value
+
+
+class SectionSerializer(serializers.ModelSerializer):
+    class Meta:
+        model = Section
+        fields = [
+            "id", "title", "order", "start_chapter_index",
+            "end_chapter_index", "estimated_reading_minutes", "created_at",
+        ]
+        read_only_fields = ["id", "created_at"]
+
+
+class SectionAdjustSerializer(serializers.Serializer):
+    """Payload for manual section adjustments (merge/split)."""
+    operation = serializers.ChoiceField(choices=["merge", "split"])
+    section_ids = serializers.ListField(
+        child=serializers.IntegerField(), min_length=1,
+        help_text="For merge: list of section IDs to merge. For split: [section_id] to split."
+    )
+    split_at = serializers.IntegerField(
+        required=False, default=2, min_value=2,
+        help_text="Number of new sections when splitting"
+    )
+
+
+class ReadingScheduleSerializer(serializers.ModelSerializer):
+    section_details = serializers.SerializerMethodField()
+
+    class Meta:
+        model = ReadingSchedule
+        fields = [
+            "id", "meeting_number", "week_date", "section_ids",
+            "section_details", "created_at",
+        ]
+        read_only_fields = ["id", "created_at"]
+
+    def get_section_details(self, obj: ReadingSchedule) -> list[dict]:
+        sections = Section.objects.filter(
+            id__in=obj.section_ids, group_book=obj.group_book
+        ).order_by("order")
+        return SectionSerializer(sections, many=True).data
+
+
+class MemberProgressSerializer(serializers.ModelSerializer):
+    user_email = serializers.CharField(source="user.email", read_only=True)
+    user_username = serializers.CharField(source="user.username", read_only=True)
+    current_section_title = serializers.SerializerMethodField()
+
+    class Meta:
+        model = MemberProgress
+        fields = [
+            "id", "user", "user_email", "user_username",
+            "current_section", "current_section_title",
+            "completed_sections", "updated_at",
+        ]
+        read_only_fields = ["id", "updated_at"]
+
+    def get_current_section_title(self, obj: MemberProgress) -> str | None:
+        if obj.current_section:
+            return obj.current_section.title
+        return None
+
+
+class GroupBookListSerializer(serializers.ModelSerializer):
+    ebook = EBookListSerializer(read_only=True)
+    uploaded_by_email = serializers.CharField(source="uploaded_by.email", read_only=True)
+    section_count = serializers.SerializerMethodField()
+
+    class Meta:
+        model = GroupBook
+        fields = [
+            "id", "title", "status", "ebook", "uploaded_by",
+            "uploaded_by_email", "section_count", "created_at", "updated_at",
+        ]
+
+    def get_section_count(self, obj: GroupBook) -> int:
+        return obj.sections.count()
+
+
+class GroupBookDetailSerializer(serializers.ModelSerializer):
+    ebook = EBookListSerializer(read_only=True)
+    uploaded_by_email = serializers.CharField(source="uploaded_by.email", read_only=True)
+    sections = SectionSerializer(many=True, read_only=True)
+    schedules = ReadingScheduleSerializer(source="schedules", many=True, read_only=True)
+
+    class Meta:
+        model = GroupBook
+        fields = [
+            "id", "group", "title", "status", "ebook",
+            "uploaded_by", "uploaded_by_email",
+            "sections", "schedules", "created_at", "updated_at",
+        ]
+
+
+class GroupBookCreateSerializer(serializers.Serializer):
+    ebook_id = serializers.IntegerField()
+    title = serializers.CharField(max_length=512, required=False)
+
+    def validate_ebook_id(self, value: int) -> int:
+        from apps.books.models import EBook
+        if not EBook.objects.filter(id=value).exists():
+            raise serializers.ValidationError("EBook not found.")
+        # Check format is EPUB
+        ebook = EBook.objects.get(id=value)
+        if ebook.format != "epub":
+            raise serializers.ValidationError("Only EPUB format is supported for group books.")
+        return value
+
+    def validate(self, data: dict) -> dict:
+        request = self.context.get("request")
+        if request and not data.get("title"):
+            from apps.books.models import EBook
+            ebook = EBook.objects.get(id=data["ebook_id"])
+            data["title"] = ebook.title
+        return data
@@ -0,0 +1,241 @@
+"""Automatic section detection and meeting recommendation for group books."""
+
+from __future__ import annotations
+
+import logging
+from datetime import date, timedelta
+from typing import Any
+
+from django.db.models import QuerySet
+
+from apps.books.models import BookChapter, EBook
+from apps.groups.models import GroupBook, ReadingSchedule, Section
+
+logger = logging.getLogger(__name__)
+
+WORDS_PER_MINUTE = 250  # Average reading speed
+
+
+def _fetch_chapter_text(ebook: EBook, chapter: BookChapter) -> str:
+    """Extract plain text from a chapter for word counting."""
+    try:
+        from ebooklib import epub
+        from bs4 import BeautifulSoup
+    except ImportError:
+        return ""
+
+    try:
+        book = epub.read_epub(ebook.file.path)
+        href = chapter.href or ""
+        for item in book.get_items():
+            item_name = item.get_name() or ""
+            if href and (item_name.endswith(href) or href.endswith(item_name)):
+                content = item.get_content()
+                soup = BeautifulSoup(content, "html.parser")
+                body = soup.find("body")
+                if body:
+                    return body.get_text(separator=" ", strip=True)
+                return soup.get_text(separator=" ", strip=True)
+        return ""
+    except Exception:
+        logger.exception("Failed to extract text for chapter %s", chapter.id)
+        return ""
+
+
+def _estimate_reading_minutes(text: str) -> int:
+    """Estimate reading time based on word count at WORDS_PER_MINUTE."""
+    word_count = len(text.split())
+    if word_count == 0:
+        return 1
+    return max(1, round(word_count / WORDS_PER_MINUTE))
+
+
+def detect_sections(group_book: GroupBook) -> list[dict[str, Any]]:
+    """Auto-detect sections from a GroupBook's chapters.
+
+    Groups consecutive chapters into logical sections based on TOC structure.
+    Top-level TOC entries become sections; if there are very few (< 3),
+    groups of ~5 chapters become sections instead.
+    """
+    ebook = group_book.ebook
+    chapters = list(
+        BookChapter.objects.filter(ebook=ebook).order_by("index").select_related("ebook")
+    )
+
+    if not chapters:
+        return []
+
+    top_level = [ch for ch in chapters if not ch.children or len(ch.children) == 0]
+    has_children = [ch for ch in chapters if ch.children and len(ch.children) > 0]
+
+    sections: list[dict[str, Any]] = []
+
+    if len(has_children) >= 3:
+        # Use TOC structure: each top-level chapter (with children) is a section
+        for idx, ch in enumerate(has_children):
+            # Find all child chapters belonging to this parent
+            child_indices = _collect_child_indices(chapters, ch, idx)
+            start_idx = ch.index
+            end_idx = child_indices[-1] if child_indices else start_idx
+
+            section_chapters = [c for c in chapters if start_idx <= c.index <= end_idx]
+            total_text = ""
+            for sc in section_chapters:
+                total_text += " " + _fetch_chapter_text(ebook, sc)
+
+            sections.append({
+                "title": ch.title,
+                "order": idx + 1,
+                "start_chapter_index": start_idx,
+                "end_chapter_index": end_idx + 1,
+                "estimated_reading_minutes": _estimate_reading_minutes(total_text),
+            })
+    else:
+        # Group chapters into chunks of ~5
+        chunk_size = max(1, len(top_level) // 6 if len(top_level) > 6 else 5)
+        chunk_size = max(3, min(chunk_size, 10))
+
+        group_start = 0
+        section_order = 1
+        total = len(top_level) or len(chapters)
+        source = top_level or chapters
+
+        while group_start < total:
+            group_end = min(group_start + chunk_size, total)
+            chunk = source[group_start:group_end]
+
+            total_text = ""
+            for ch in chunk:
+                total_text += " " + _fetch_chapter_text(ebook, ch)
+
+            first_title = chunk[0].title if chunk else "Section"
+            last_title = chunk[-1].title if len(chunk) > 1 else ""
+            title = f"{first_title}" if not last_title or first_title == last_title else f"{first_title} — {last_title}"
+
+            sections.append({
+                "title": title,
+                "order": section_order,
+                "start_chapter_index": chunk[0].index,
+                "end_chapter_index": chunk[-1].index + 1,
+                "estimated_reading_minutes": _estimate_reading_minutes(total_text),
+            })
+            group_start = group_end
+            section_order += 1
+
+    return sections
+
+
+def _collect_child_indices(chapters: list[BookChapter], parent: BookChapter, parent_idx: int) -> list[int]:
+    """Collect indices of all chapters that are children of the given parent TOC entry."""
+    indices: list[int] = [parent.index]
+    child_hrefs: set[str] = set()
+    for child in parent.children:
+        if isinstance(child, dict):
+            child_hrefs.add(child.get("href", ""))
+        elif hasattr(child, "href"):
+            child_hrefs.add(getattr(child, "href", ""))
+
+    for ch in chapters:
+        if ch.index == parent.index:
+            continue
+        if ch.href in child_hrefs or any(
+            ch.href.endswith(h) or h.endswith(ch.href) for h in child_hrefs
+        ):
+            indices.append(ch.index)
+
+    # Also include chapters between this parent and the next parent
+    if parent_idx + 1 < len(chapters):
+        next_parent = chapters[parent_idx + 1]
+        for ch in chapters:
+            if parent.index < ch.index < next_parent.index:
+                indices.append(ch.index)
+
+    return sorted(set(indices))
+
+
+def apply_sections(group_book: GroupBook) -> list[Section]:
+    """Detect sections and persist them to the database, replacing existing ones."""
+    Section.objects.filter(group_book=group_book).delete()
+    sections_data = detect_sections(group_book)
+    created: list[Section] = []
+    for data in sections_data:
+        section = Section.objects.create(
+            group_book=group_book,
+            title=data["title"],
+            order=data["order"],
+            start_chapter_index=data["start_chapter_index"],
+            end_chapter_index=data["end_chapter_index"],
+            estimated_reading_minutes=data["estimated_reading_minutes"],
+        )
+        created.append(section)
+    return created
+
+
+def recommend_meetings(group_book: GroupBook, num_meetings: int = 4) -> list[dict[str, Any]]:
+    """Recommend which sections to assign to each weekly meeting.
+
+    Distributes sections across meetings, trying to balance total reading time.
+    Returns a list of meeting assignments ready for schedule creation.
+    """
+    sections = list(
+        Section.objects.filter(group_book=group_book).order_by("order")
+    )
+
+    if not sections:
+        return []
+
+    # Calculate total minutes to distribute
+    total_minutes = sum(s.estimated_reading_minutes for s in sections)
+    target_per_meeting = total_minutes / num_meetings
+
+    meetings: list[dict[str, Any]] = []
+    current_meeting: list[int] = []
+    current_minutes = 0
+
+    for section in sections:
+        if current_meeting and current_minutes + section.estimated_reading_minutes > target_per_meeting * 1.4:
+            # Start new meeting if adding this section would overshoot too much
+            if len(meetings) < num_meetings - 1:
+                meetings.append({
+                    "meeting_number": len(meetings) + 1,
+                    "section_ids": current_meeting,
+                    "total_minutes": current_minutes,
+                })
+                current_meeting = []
+                current_minutes = 0
+
+        current_meeting.append(section.id)
+        current_minutes += section.estimated_reading_minutes
+
+    # Add the last meeting
+    if current_meeting:
+        meetings.append({
+            "meeting_number": len(meetings) + 1,
+            "section_ids": current_meeting,
+            "total_minutes": current_minutes,
+        })
+
+    # If we have fewer than num_meetings, we could split the largest one
+    # For now, just return what we have
+    return meetings
+
+
+def apply_schedule(group_book: GroupBook, num_meetings: int = 4) -> list[ReadingSchedule]:
+    """Generate and persist a reading schedule."""
+    ReadingSchedule.objects.filter(group_book=group_book).delete()
+
+    recommendations = recommend_meetings(group_book, num_meetings)
+    today = date.today()
+
+    created: list[ReadingSchedule] = []
+    for rec in recommendations:
+        week_date = today + timedelta(weeks=rec["meeting_number"] - 1)
+        schedule = ReadingSchedule.objects.create(
+            group_book=group_book,
+            meeting_number=rec["meeting_number"],
+            week_date=week_date,
+            section_ids=rec["section_ids"],
+        )
+        created.append(schedule)
+
+    return created
@@ -0,0 +1,43 @@
+from django.urls import include, path
+from rest_framework.routers import DefaultRouter
+
+from apps.groups.views import GroupBookViewSet, ReadingGroupViewSet
+
+# ReadingGroup routes (standard ViewSet)
+router = DefaultRouter()
+router.register(r"", ReadingGroupViewSet, basename="group")
+
+urlpatterns = [
+    path("", include(router.urls)),
+    # Nested GroupBook routes under a group
+    path(
+        "<int:group_pk>/books/",
+        GroupBookViewSet.as_view({"get": "list", "post": "create"}),
+        name="group-book-list",
+    ),
+    path(
+        "<int:group_pk>/books/<int:pk>/",
+        GroupBookViewSet.as_view({"get": "retrieve", "delete": "destroy"}),
+        name="group-book-detail",
+    ),
+    path(
+        "<int:group_pk>/books/<int:pk>/detect-sections/",
+        GroupBookViewSet.as_view({"post": "detect_sections_action"}),
+        name="group-book-detect-sections",
+    ),
+    path(
+        "<int:group_pk>/books/<int:pk>/adjust-sections/",
+        GroupBookViewSet.as_view({"post": "adjust_sections"}),
+        name="group-book-adjust-sections",
+    ),
+    path(
+        "<int:group_pk>/books/<int:pk>/schedule/",
+        GroupBookViewSet.as_view({"get": "schedule", "post": "schedule", "delete": "schedule"}),
+        name="group-book-schedule",
+    ),
+    path(
+        "<int:group_pk>/books/<int:pk>/progress/",
+        GroupBookViewSet.as_view({"get": "progress", "patch": "progress"}),
+        name="group-book-progress",
+    ),
+]
@@ -0,0 +1,349 @@
+from __future__ import annotations
+
+import logging
+from typing import Any
+
+from django.db.models import QuerySet
+from django.shortcuts import get_object_or_404
+from rest_framework import permissions, status, viewsets
+from rest_framework.decorators import action
+from rest_framework.request import Request
+from rest_framework.response import Response
+
+from apps.books.models import EBook
+from apps.groups.models import (
+    GroupBook,
+    MemberProgress,
+    ReadingGroup,
+    ReadingGroupMembership,
+    ReadingSchedule,
+    Section,
+)
+from apps.groups.serializers import (
+    AddMemberSerializer,
+    GroupBookCreateSerializer,
+    GroupBookDetailSerializer,
+    GroupBookListSerializer,
+    MemberProgressSerializer,
+    ReadingGroupCreateSerializer,
+    ReadingGroupDetailSerializer,
+    ReadingGroupListSerializer,
+    ReadingScheduleSerializer,
+    SectionAdjustSerializer,
+    SectionSerializer,
+)
+from apps.groups.services.section_splitting import (
+    apply_schedule,
+    apply_sections,
+    detect_sections,
+)
+
+logger = logging.getLogger(__name__)
+
+
+class IsGroupAdmin(permissions.BasePermission):
+    """Only the group admin can modify group resources."""
+
+    def has_permission(self, request: Request, view: object) -> bool:
+        if not request.user.is_authenticated:
+            return False
+        if view.action in ("list", "retrieve"):
+            return True
+        group_id = view.kwargs.get("pk") or view.kwargs.get("group_pk")
+        if group_id:
+            return ReadingGroup.objects.filter(id=group_id, admin=request.user).exists()
+        return True
+
+    def has_object_permission(self, request: Request, view: object, obj: ReadingGroup) -> bool:
+        if request.method in permissions.SAFE_METHODS:
+            return True
+        return obj.admin == request.user
+
+
+class IsGroupMember(permissions.BasePermission):
+    """Only group members (including admin) can view group content."""
+
+    def has_permission(self, request: Request, view: object) -> bool:
+        if not request.user.is_authenticated:
+            return False
+        group_id = view.kwargs.get("pk") or view.kwargs.get("group_pk")
+        if group_id:
+            return ReadingGroupMembership.objects.filter(
+                group_id=group_id, user=request.user
+            ).exists()
+        return True
+
+
+class ReadingGroupViewSet(viewsets.ModelViewSet):
+    permission_classes = [permissions.IsAuthenticated, IsGroupAdmin]
+    queryset = ReadingGroup.objects.prefetch_related("memberships__user")
+
+    def get_serializer_class(self):
+        if self.action == "create":
+            return ReadingGroupCreateSerializer
+        if self.action == "retrieve":
+            return ReadingGroupDetailSerializer
+        return ReadingGroupListSerializer
+
+    def get_queryset(self) -> QuerySet[ReadingGroup]:
+        user = self.request.user
+        return ReadingGroup.objects.filter(
+            memberships__user=user
+        ).prefetch_related("memberships__user").distinct()
+
+    def perform_create(self, serializer: ReadingGroupCreateSerializer) -> ReadingGroup:
+        group = serializer.save(admin=self.request.user)
+        ReadingGroupMembership.objects.create(
+            user=self.request.user, group=group, role=ReadingGroupMembership.Role.ADMIN
+        )
+        return group
+
+    @action(detail=True, methods=["post"], permission_classes=[IsGroupAdmin])
+    def add_member(self, request: Request, pk: int | None = None) -> Response:
+        group = self.get_object()
+        member_serializer = AddMemberSerializer(data=request.data)
+        member_serializer.is_valid(raise_exception=True)
+
+        user_id = member_serializer.validated_data["user_id"]
+        from django.conf import settings
+        User = settings.AUTH_USER_MODEL
+        new_member = get_object_or_404(User, id=user_id)
+
+        if ReadingGroupMembership.objects.filter(group=group, user=new_member).exists():
+            return Response(
+                {"detail": "User is already a member of this group."},
+                status=status.HTTP_409_CONFLICT,
+            )
+
+        membership = ReadingGroupMembership.objects.create(
+            user=new_member, group=group, role=ReadingGroupMembership.Role.MEMBER
+        )
+        from apps.groups.serializers import ReadingGroupMembershipSerializer
+        return Response(
+            ReadingGroupMembershipSerializer(membership).data,
+            status=status.HTTP_201_CREATED,
+        )
+
+    @action(detail=True, methods=["post"], permission_classes=[IsGroupAdmin])
+    def remove_member(self, request: Request, pk: int | None = None) -> Response:
+        group = self.get_object()
+        member_serializer = AddMemberSerializer(data=request.data)
+        member_serializer.is_valid(raise_exception=True)
+
+        user_id = member_serializer.validated_data["user_id"]
+        if user_id == group.admin_id:
+            return Response(
+                {"detail": "Cannot remove the group admin."},
+                status=status.HTTP_400_BAD_REQUEST,
+            )
+
+        deleted, _ = ReadingGroupMembership.objects.filter(
+            group=group, user_id=user_id
+        ).delete()
+        if not deleted:
+            return Response(
+                {"detail": "User is not a member of this group."},
+                status=status.HTTP_404_NOT_FOUND,
+            )
+        return Response(status=status.HTTP_204_NO_CONTENT)
+
+
+class GroupBookViewSet(viewsets.ModelViewSet):
+    permission_classes = [permissions.IsAuthenticated, IsGroupAdmin]
+
+    def get_serializer_class(self):
+        if self.action == "create":
+            return GroupBookCreateSerializer
+        if self.action == "retrieve":
+            return GroupBookDetailSerializer
+        return GroupBookListSerializer
+
+    def get_queryset(self) -> QuerySet[GroupBook]:
+        group_id = self.kwargs.get("group_pk")
+        return GroupBook.objects.filter(
+            group_id=group_id
+        ).select_related("ebook", "ebook__user", "uploaded_by").prefetch_related(
+            "sections", "schedules"
+        )
+
+    def perform_create(self, serializer: GroupBookCreateSerializer) -> GroupBook:
+        group = get_object_or_404(ReadingGroup, id=self.kwargs["group_pk"])
+        ebook = get_object_or_404(EBook, id=serializer.validated_data["ebook_id"])
+        title = serializer.validated_data.get("title") or ebook.title
+
+        # Mark existing active books as replaced
+        GroupBook.objects.filter(group=group, status=GroupBook.Status.ACTIVE).update(
+            status=GroupBook.Status.REPLACED
+        )
+
+        group_book = GroupBook.objects.create(
+            group=group,
+            ebook=ebook,
+            uploaded_by=self.request.user,
+            title=title,
+            status=GroupBook.Status.ACTIVE,
+        )
+
+        # Auto-detect sections
+        try:
+            apply_sections(group_book)
+        except Exception:
+            logger.exception("Auto-section detection failed for group_book %s", group_book.id)
+
+        # Auto-generate schedule
+        try:
+            apply_schedule(group_book)
+        except Exception:
+            logger.exception("Schedule generation failed for group_book %s", group_book.id)
+
+        return group_book
+
+    @action(detail=True, methods=["post"], url_path="detect-sections")
+    def detect_sections_action(self, request: Request, group_pk: int | None = None, pk: int | None = None) -> Response:
+        group_book = self.get_object()
+        try:
+            sections = apply_sections(group_book)
+        except Exception as exc:
+            logger.exception("Section detection failed for group_book %s", group_book.id)
+            return Response({"error": str(exc)}, status=status.HTTP_500_INTERNAL_SERVER_ERROR)
+        return Response(SectionSerializer(sections, many=True).data)
+
+    @action(detail=True, methods=["post"], url_path="adjust-sections")
+    def adjust_sections(self, request: Request, group_pk: int | None = None, pk: int | None = None) -> Response:
+        group_book = self.get_object()
+        adjust_serializer = SectionAdjustSerializer(data=request.data)
+        adjust_serializer.is_valid(raise_exception=True)
+
+        operation = adjust_serializer.validated_data["operation"]
+        section_ids: list[int] = adjust_serializer.validated_data["section_ids"]
+
+        if operation == "merge":
+            if len(section_ids) < 2:
+                return Response(
+                    {"error": "At least 2 section IDs required for merge."},
+                    status=status.HTTP_400_BAD_REQUEST,
+                )
+            sections = list(
+                Section.objects.filter(id__in=section_ids, group_book=group_book).order_by("order")
+            )
+            if len(sections) < 2:
+                return Response(
+                    {"error": "Not enough valid sections found."},
+                    status=status.HTTP_400_BAD_REQUEST,
+                )
+            merged_title = " — ".join(s.title for s in sections)
+            merged_minutes = sum(s.estimated_reading_minutes for s in sections)
+            merged_start = sections[0].start_chapter_index
+            merged_end = sections[-1].end_chapter_index
+            merged_order = sections[0].order
+
+            # Delete old sections
+            Section.objects.filter(id__in=section_ids, group_book=group_book).delete()
+
+            # Create merged section
+            merged = Section.objects.create(
+                group_book=group_book,
+                title=merged_title,
+                order=merged_order,
+                start_chapter_index=merged_start,
+                end_chapter_index=merged_end,
+                estimated_reading_minutes=merged_minutes,
+            )
+            # Reorder remaining sections
+            _renumber_sections(group_book)
+            return Response(SectionSerializer(merged).data)
+
+        if operation == "split":
+            if len(section_ids) != 1:
+                return Response(
+                    {"error": "Exactly 1 section ID required for split."},
+                    status=status.HTTP_400_BAD_REQUEST,
+                )
+            split_at = adjust_serializer.validated_data.get("split_at", 2)
+            section = get_object_or_404(Section, id=section_ids[0], group_book=group_book)
+            chapters = section.end_chapter_index - section.start_chapter_index
+            if chapters < split_at:
+                return Response(
+                    {"error": f"Section only has {chapters} chapters, cannot split into {split_at}."},
+                    status=status.HTTP_400_BAD_REQUEST,
+                )
+
+            # Delete original
+            orig_order = section.order
+            orig_title = section.title
+            section.delete()
+
+            # Create split sections
+            chunk_size = max(1, chapters // split_at)
+            new_sections: list[Section] = []
+            for i in range(split_at):
+                start_idx = section.start_chapter_index + i * chunk_size
+                end_idx = start_idx + chunk_size if i < split_at - 1 else section.end_chapter_index
+                minutes_each = max(1, section.estimated_reading_minutes // split_at)
+                new_sec = Section.objects.create(
+                    group_book=group_book,
+                    title=f"{orig_title} (Part {i + 1})",
+                    order=orig_order + i,
+                    start_chapter_index=start_idx,
+                    end_chapter_index=end_idx,
+                    estimated_reading_minutes=minutes_each,
+                )
+                new_sections.append(new_sec)
+
+            _renumber_sections(group_book)
+            return Response(SectionSerializer(new_sections, many=True).data)
+
+        return Response({"error": "Invalid operation."}, status=status.HTTP_400_BAD_REQUEST)
+
+    @action(detail=True, methods=["get", "post", "delete"], url_path="schedule")
+    def schedule(self, request: Request, group_pk: int | None = None, pk: int | None = None) -> Response:
+        group_book = self.get_object()
+
+        if request.method == "GET":
+            schedules = ReadingSchedule.objects.filter(group_book=group_book).order_by("meeting_number")
+            return Response(ReadingScheduleSerializer(schedules, many=True).data)
+
+        if request.method == "POST":
+            ReadingSchedule.objects.filter(group_book=group_book).delete()
+            num_meetings = int(request.data.get("num_meetings", 4))
+            try:
+                schedules = apply_schedule(group_book, num_meetings=num_meetings)
+            except Exception as exc:
+                logger.exception("Schedule generation failed for group_book %s", group_book.id)
+                return Response({"error": str(exc)}, status=status.HTTP_500_INTERNAL_SERVER_ERROR)
+            return Response(
+                ReadingScheduleSerializer(schedules, many=True).data,
+                status=status.HTTP_201_CREATED,
+            )
+
+        if request.method == "DELETE":
+            ReadingSchedule.objects.filter(group_book=group_book).delete()
+            return Response(status=status.HTTP_204_NO_CONTENT)
+
+    @action(detail=True, methods=["get", "patch"], url_path="progress")
+    def progress(self, request: Request, group_pk: int | None = None, pk: int | None = None) -> Response:
+        group_book = self.get_object()
+
+        if request.method == "GET":
+            progress_records = MemberProgress.objects.filter(
+                group_book=group_book
+            ).select_related("user", "current_section")
+            return Response(MemberProgressSerializer(progress_records, many=True).data)
+
+        # PATCH: update own progress
+        progress_obj, _created = MemberProgress.objects.get_or_create(
+            user=request.user, group_book=group_book,
+        )
+        serializer = MemberProgressSerializer(progress_obj, data=request.data, partial=True)
+        serializer.is_valid(raise_exception=True)
+        serializer.save()
+        return Response(serializer.data)
+
+
+def _renumber_sections(group_book: GroupBook) -> None:
+    """Re-number sections sequentially by their current order."""
+    sections = list(Section.objects.filter(group_book=group_book).order_by("order"))
+    for idx, section in enumerate(sections):
+        if section.order != idx + 1:
+            section.order = idx + 1
+            section.save(update_fields=["order"])
@@ -39,6 +39,7 @@ INSTALLED_APPS = [
    # Local apps
    "apps.users",
    "apps.books",
+    "apps.groups",
    "apps.annotations",
    "apps.reader",
 ]
@@ -6,6 +6,7 @@ urlpatterns = [
    path("admin/", admin.site.urls),
    path("api/auth/", include("apps.users.urls")),
    path("api/books/", include("apps.books.urls")),
+    path("api/groups/", include("apps.groups.urls")),
    path("api/annotations/", include("apps.annotations.urls")),
    path("api/reader/", include("apps.reader.urls")),
 ]
@@ -12,7 +12,9 @@ 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 RecommendationPage = lazy(() => import("./pages/RecommendationPage").then((m) => ({ default: m.RecommendationPage })));
+const GroupsPage = lazy(() => import("./pages/GroupsPage").then((m) => ({ default: m.GroupsPage })));
+const GroupDetailPage = lazy(() => import("./pages/GroupDetailPage").then((m) => ({ default: m.GroupDetailPage })));
+const GroupBookPage = lazy(() => import("./pages/GroupBookPage").then((m) => ({ default: m.GroupBookPage })));

 const AuthPage = lazy(() => import("./pages/AuthPage"));

@@ -41,11 +43,13 @@ function AppRoutes() {
        <Route path="/auth" element={isAuthenticated ? <Navigate to="/" replace /> : <AuthPage />} />
        <Route path="/" element={<ProtectedRoute><LibraryPage /></ProtectedRoute>} />
        <Route path="/books/:id" element={<ProtectedRoute><BookDetailPage /></ProtectedRoute>} />
-        <Route path="/books/:ebookId/schedule" element={<ProtectedRoute><RecommendationPage /></ProtectedRoute>} />
        <Route path="/read/:id" element={<ProtectedRoute><ReadingPage /></ProtectedRoute>} />
        <Route path="/reader/:id" element={<ProtectedRoute><ReaderRedirect /></ProtectedRoute>} />
        <Route path="/add" element={<ProtectedRoute><AddBookPage /></ProtectedRoute>} />
        <Route path="/settings" element={<ProtectedRoute><SettingsPage /></ProtectedRoute>} />
+        <Route path="/groups" element={<ProtectedRoute><GroupsPage /></ProtectedRoute>} />
+        <Route path="/groups/:groupId" element={<ProtectedRoute><GroupDetailPage /></ProtectedRoute>} />
+        <Route path="/groups/:groupId/books/:bookId" element={<ProtectedRoute><GroupBookPage /></ProtectedRoute>} />
        <Route path="/bookmarks-notes/:bookId?" element={<ProtectedRoute><BookmarksNotesPage /></ProtectedRoute>} />
        <Route path="*" element={<Navigate to="/" replace />} />
      </Routes>
@@ -6,9 +6,7 @@ import type {
  ContentResponse,
  EBookDetail,
  EBookListItem,
-  GenerateRecommendationsRequest,
  ReadingProgress,
-  ReadingSchedule,
  ReadingSettings,
  TocResponse,
 } from "../types/book";
@@ -134,64 +132,3 @@ export const booksApi = {
    return data;
  },
 };
-
-export const schedulesApi = {
-  async getSchedules(): Promise<ReadingSchedule[]> {
-    const { data } = await api.get<ReadingSchedule[]>("/books/schedules/");
-    return data;
-  },
-
-  async getSchedule(id: number): Promise<ReadingSchedule> {
-    const { data } = await api.get<ReadingSchedule>(`/books/schedules/${id}/`);
-    return data;
-  },
-
-  async generateRecommendations(request: GenerateRecommendationsRequest): Promise<ReadingSchedule> {
-    const { data } = await api.post<ReadingSchedule>("/books/schedules/", {
-      ebook_id: request.ebook_id,
-      meeting_count: request.meeting_count ?? 4,
-    });
-    return data;
-  },
-
-  async regenerateRecommendations(scheduleId: number, meetingCount?: number): Promise<ReadingSchedule> {
-    const { data } = await api.post<ReadingSchedule>(`/books/schedules/${scheduleId}/generate/`, {
-      meeting_count: meetingCount ?? 4,
-    });
-    return data;
-  },
-
-  async confirmSchedule(scheduleId: number): Promise<ReadingSchedule> {
-    const { data } = await api.post<ReadingSchedule>(`/books/schedules/${scheduleId}/confirm/`, {
-      confirm: true,
-    });
-    return data;
-  },
-
-  async updateMeeting(
-    scheduleId: number,
-    meetingId: number,
-    update: { chapter_ids?: number[]; title?: string; meeting_index?: number },
-  ): Promise<unknown> {
-    const { data } = await api.patch(
-      `/books/schedules/${scheduleId}/meetings/${meetingId}/`,
-      update,
-    );
-    return data;
-  },
-
-  async reorderMeetings(
-    scheduleId: number,
-    meetings: { id: number; meeting_index: number }[],
-  ): Promise<ReadingSchedule> {
-    const { data } = await api.patch<ReadingSchedule>(
-      `/books/schedules/${scheduleId}/reorder/`,
-      { meetings },
-    );
-    return data;
-  },
-
-  async deleteSchedule(id: number): Promise<void> {
-    await api.delete(`/books/schedules/${id}/`);
-  },
-};
@@ -0,0 +1,151 @@
+import api from "./client";
+import type {
+  AddMemberPayload,
+  AdjustSectionsPayload,
+  CreateGroupBookPayload,
+  CreateGroupPayload,
+  GroupBook,
+  GroupBookDetail,
+  MemberProgress,
+  ReadingGroup,
+  ReadingGroupDetail,
+  ReadingSchedule,
+  Section,
+} from "../types/group";
+
+export const groupsApi = {
+  // ---- Reading Groups ----
+
+  async listGroups(): Promise<ReadingGroup[]> {
+    const { data } = await api.get<{ count: number; results: ReadingGroup[] } | ReadingGroup[]>(
+      "/groups/"
+    );
+    if (Array.isArray(data)) return data;
+    return data.results ?? [];
+  },
+
+  async getGroup(id: number): Promise<ReadingGroupDetail> {
+    const { data } = await api.get<ReadingGroupDetail>(`/groups/${id}/`);
+    return data;
+  },
+
+  async createGroup(payload: CreateGroupPayload): Promise<ReadingGroup> {
+    const { data } = await api.post<ReadingGroup>("/groups/", payload);
+    return data;
+  },
+
+  async deleteGroup(id: number): Promise<void> {
+    await api.delete(`/groups/${id}/`);
+  },
+
+  async addMember(groupId: number, payload: AddMemberPayload): Promise<void> {
+    await api.post(`/groups/${groupId}/add_member/`, payload);
+  },
+
+  async removeMember(groupId: number, payload: AddMemberPayload): Promise<void> {
+    await api.post(`/groups/${groupId}/remove_member/`, payload);
+  },
+
+  // ---- Group Books ----
+
+  async listGroupBooks(groupId: number): Promise<GroupBook[]> {
+    const { data } = await api.get<GroupBook[]>(`/groups/${groupId}/books/`);
+    return Array.isArray(data) ? data : (data as { results: GroupBook[] }).results ?? [];
+  },
+
+  async getGroupBook(groupId: number, bookId: number): Promise<GroupBookDetail> {
+    const { data } = await api.get<GroupBookDetail>(`/groups/${groupId}/books/${bookId}/`);
+    return data;
+  },
+
+  async createGroupBook(
+    groupId: number,
+    payload: CreateGroupBookPayload
+  ): Promise<GroupBookDetail> {
+    const { data } = await api.post<GroupBookDetail>(
+      `/groups/${groupId}/books/`,
+      payload
+    );
+    return data;
+  },
+
+  async deleteGroupBook(groupId: number, bookId: number): Promise<void> {
+    await api.delete(`/groups/${groupId}/books/${bookId}/`);
+  },
+
+  // ---- Sections ----
+
+  async detectSections(
+    groupId: number,
+    bookId: number
+  ): Promise<Section[]> {
+    const { data } = await api.post<Section[]>(
+      `/groups/${groupId}/books/${bookId}/detect-sections/`
+    );
+    return data;
+  },
+
+  async adjustSections(
+    groupId: number,
+    bookId: number,
+    payload: AdjustSectionsPayload
+  ): Promise<Section | Section[]> {
+    const { data } = await api.post<Section | Section[]>(
+      `/groups/${groupId}/books/${bookId}/adjust-sections/`,
+      payload
+    );
+    return data;
+  },
+
+  // ---- Schedule ----
+
+  async getSchedule(
+    groupId: number,
+    bookId: number
+  ): Promise<ReadingSchedule[]> {
+    const { data } = await api.get<ReadingSchedule[]>(
+      `/groups/${groupId}/books/${bookId}/schedule/`
+    );
+    return data;
+  },
+
+  async generateSchedule(
+    groupId: number,
+    bookId: number,
+    numMeetings: number = 4
+  ): Promise<ReadingSchedule[]> {
+    const { data } = await api.post<ReadingSchedule[]>(
+      `/groups/${groupId}/books/${bookId}/schedule/`,
+      { num_meetings: numMeetings }
+    );
+    return data;
+  },
+
+  async deleteSchedule(groupId: number, bookId: number): Promise<void> {
+    await api.delete(`/groups/${groupId}/books/${bookId}/schedule/`);
+  },
+
+  // ---- Progress ----
+
+  async getProgress(
+    groupId: number,
+    bookId: number
+  ): Promise<MemberProgress[]> {
+    const { data } = await api.get<MemberProgress[]>(
+      `/groups/${groupId}/books/${bookId}/progress/`
+    );
+    return data;
+  },
+
+  async updateProgress(
+    groupId: number,
+    bookId: number,
+    payload: { current_section?: number; completed_sections?: number[] }
+  ): Promise<MemberProgress> {
+    const { data } = await api.patch<MemberProgress>(
+      `/groups/${groupId}/books/${bookId}/progress/`,
+      payload
+    );
+    return data;
+  },
+};
@@ -1,5 +1,4 @@
 import { useEffect, useLayoutEffect, useRef, useState } from "react";
-import { useNavigate } from "react-router-dom";
 import { useTranslation } from "react-i18n-lite";
 import { booksApi } from "../api/books";
 import { getApiErrorMessage } from "../api/errors";
@@ -47,7 +46,6 @@ export function BookContextMenu({
  const { t, language } = useTranslation();
  const locale = language as SupportedLanguage;
  const { showToast } = useToast();
-  const navigate = useNavigate();
  const menuRef = useRef<HTMLDivElement>(null);
  const [position, setPosition] = useState({ left: x, top: y });
  const [activeAction, setActiveAction] = useState<ActionKind>(null);
@@ -150,18 +148,6 @@ export function BookContextMenu({
      >
        {activeAction === "sync" ? t("contextMenu.syncingMetadata") : t("contextMenu.syncMetadata")}
      </button>
-      <button
-        type="button"
-        className={styles.item}
-        role="menuitem"
-        disabled={busy}
-        onClick={() => {
-          navigate(`/books/${book.id}/schedule`);
-          onClose();
-        }}
-      >
-        📅 Schedule Reading
-      </button>
      <div className={styles.separator} role="separator" />
      <button
        type="button"
@@ -245,6 +245,54 @@ const enUS = {
    home: "Home",
    bookmarksNotes: "Bookmarks & Notes",
  },
+  groups: {
+    title: "Reading Groups",
+    createGroup: "Create Group",
+    create: "Create",
+    cancel: "Cancel",
+    groupName: "Group Name",
+    groupNamePlaceholder: "Enter group name",
+    description: "Description",
+    descriptionPlaceholder: "What is this group about?",
+    optional: "Optional",
+    noGroups: "No groups yet",
+    noGroupsHint: "Create a reading group to start reading together!",
+    members: "Members",
+    admin: "Admin",
+    addMember: "Add Member",
+    memberIdPlaceholder: "Enter user ID",
+    add: "Add",
+    remove: "Remove",
+    books: "Group Books",
+    uploadEpub: "Upload EPUB",
+    selectEbook: "Select an EPUB to share with the group",
+    noEpubBooks: "No EPUB files uploaded yet",
+    uploadFirst: "Upload an EPUB first",
+    confirmUpload: "Confirm Upload",
+    noBooks: "No books in this group yet",
+    sections: "Sections",
+    schedule: "Schedule",
+    progress: "Progress",
+    detectSections: "Auto-Detect Sections",
+    mergeSections: "Merge Sections",
+    selectSectionsHint: "Click sections to select for merging",
+    merge: "Merge",
+    clear: "Clear",
+    split: "Split",
+    splitInto: "Split into",
+    parts: "parts",
+    splitBtn: "Split",
+    noSections: "No sections detected yet",
+    noSectionsHint: 'Click "Auto-Detect Sections" to parse the EPUB chapters into reading sections.',
+    readingSchedule: "Reading Schedule",
+    generateSchedule: "Generate Schedule",
+    noSchedule: "No schedule generated yet",
+    noScheduleHint: "Detect sections first, then generate a reading schedule for your group.",
+    meeting: "Meeting",
+    memberProgress: "Member Progress",
+    noProgress: "No progress data yet",
+    noProgressHint: "Members will show progress once they start reading.",
+  },
 } as const;

 export default enUS;
@@ -247,6 +247,54 @@ const esES: Locale = {
    home: "Inicio",
    bookmarksNotes: "Marcadores y notas",
  },
+  groups: {
+    title: "Grupos de Lectura",
+    createGroup: "Crear Grupo",
+    create: "Crear",
+    cancel: "Cancelar",
+    groupName: "Nombre del Grupo",
+    groupNamePlaceholder: "Ingresa el nombre del grupo",
+    description: "Descripción",
+    descriptionPlaceholder: "¿De qué trata este grupo?",
+    optional: "Opcional",
+    noGroups: "Aún no hay grupos",
+    noGroupsHint: "¡Crea un grupo de lectura para leer juntos!",
+    members: "Miembros",
+    admin: "Admin",
+    addMember: "Agregar Miembro",
+    memberIdPlaceholder: "Ingresa ID de usuario",
+    add: "Agregar",
+    remove: "Eliminar",
+    books: "Libros del Grupo",
+    uploadEpub: "Subir EPUB",
+    selectEbook: "Selecciona un EPUB para compartir con el grupo",
+    noEpubBooks: "No hay archivos EPUB subidos aún",
+    uploadFirst: "Sube un EPUB primero",
+    confirmUpload: "Confirmar Subida",
+    noBooks: "No hay libros en este grupo aún",
+    sections: "Secciones",
+    schedule: "Calendario",
+    progress: "Progreso",
+    detectSections: "Auto-Detectar Secciones",
+    mergeSections: "Fusionar Secciones",
+    selectSectionsHint: "Haz clic en las secciones para seleccionar y fusionar",
+    merge: "Fusionar",
+    clear: "Limpiar",
+    split: "Dividir",
+    splitInto: "Dividir en",
+    parts: "partes",
+    splitBtn: "Dividir",
+    noSections: "No se detectaron secciones",
+    noSectionsHint: 'Haz clic en "Auto-Detectar Secciones" para analizar los capítulos del EPUB.',
+    readingSchedule: "Calendario de Lectura",
+    generateSchedule: "Generar Calendario",
+    noSchedule: "No hay calendario generado",
+    noScheduleHint: "Detecta secciones primero, luego genera un calendario de lectura para tu grupo.",
+    meeting: "Reunión",
+    memberProgress: "Progreso de Miembros",
+    noProgress: "Sin datos de progreso",
+    noProgressHint: "Los miembros mostrarán progreso cuando comiencen a leer.",
+  },
 };

 export default esES;
@@ -0,0 +1,426 @@
+import React, { useCallback, useEffect, useState } from "react";
+import { useNavigate, useParams } from "react-router-dom";
+import { useTranslation } from "react-i18n-lite";
+import { groupsApi } from "../api/groups";
+import { getApiErrorMessage } from "../api/errors";
+import type {
+  GroupBookDetail,
+  ReadingSchedule,
+  Section,
+  MemberProgress,
+} from "../types/group";
+
+export function GroupBookPage() {
+  const { t } = useTranslation();
+  const navigate = useNavigate();
+  const { groupId, bookId } = useParams<{ groupId: string; bookId: string }>();
+
+  const [book, setBook] = useState<GroupBookDetail | null>(null);
+  const [sections, setSections] = useState<Section[]>([]);
+  const [schedules, setSchedules] = useState<ReadingSchedule[]>([]);
+  const [progress, setProgress] = useState<MemberProgress[]>([]);
+  const [loading, setLoading] = useState(true);
+  const [error, setError] = useState<string | null>(null);
+  const [tab, setTab] = useState<"sections" | "schedule" | "progress">("sections");
+
+  // Merge state
+  const [selectedForMerge, setSelectedForMerge] = useState<number[]>([]);
+  const [splitSectionId, setSplitSectionId] = useState<number | null>(null);
+  const [splitAt, setSplitAt] = useState(2);
+
+  const gId = Number(groupId);
+  const bId = Number(bookId);
+
+  const loadData = useCallback(async () => {
+    if (!gId || !bId) return;
+    setLoading(true);
+    try {
+      const [bookData, schedData, progData] = await Promise.all([
+        groupsApi.getGroupBook(gId, bId),
+        groupsApi.getSchedule(gId, bId).catch(() => [] as ReadingSchedule[]),
+        groupsApi.getProgress(gId, bId).catch(() => [] as MemberProgress[]),
+      ]);
+      setBook(bookData);
+      setSections(bookData.sections ?? []);
+      setSchedules(schedData);
+      setProgress(progData);
+    } catch (err) {
+      setError(getApiErrorMessage(err, "Failed to load book"));
+    } finally {
+      setLoading(false);
+    }
+  }, [gId, bId]);
+
+  useEffect(() => {
+    loadData();
+  }, [loadData]);
+
+  const handleDetectSections = async () => {
+    if (!gId || !bId) return;
+    try {
+      const newSections = await groupsApi.detectSections(gId, bId);
+      setSections(newSections);
+    } catch (err) {
+      setError(getApiErrorMessage(err, "Failed to detect sections"));
+    }
+  };
+
+  const handleMerge = async () => {
+    if (selectedForMerge.length < 2 || !gId || !bId) return;
+    try {
+      await groupsApi.adjustSections(gId, bId, {
+        operation: "merge",
+        section_ids: selectedForMerge,
+      });
+      setSelectedForMerge([]);
+      await loadData();
+    } catch (err) {
+      setError(getApiErrorMessage(err, "Failed to merge sections"));
+    }
+  };
+
+  const handleSplit = async () => {
+    if (!splitSectionId || !gId || !bId) return;
+    try {
+      await groupsApi.adjustSections(gId, bId, {
+        operation: "split",
+        section_ids: [splitSectionId],
+        split_at: splitAt,
+      });
+      setSplitSectionId(null);
+      await loadData();
+    } catch (err) {
+      setError(getApiErrorMessage(err, "Failed to split section"));
+    }
+  };
+
+  const handleGenerateSchedule = async () => {
+    if (!gId || !bId) return;
+    try {
+      const newSched = await groupsApi.generateSchedule(gId, bId, 4);
+      setSchedules(newSched);
+    } catch (err) {
+      setError(getApiErrorMessage(err, "Failed to generate schedule"));
+    }
+  };
+
+  const toggleMergeSelect = (id: number) => {
+    setSelectedForMerge((prev) =>
+      prev.includes(id) ? prev.filter((s) => s !== id) : [...prev, id]
+    );
+  };
+
+  const formatMinutes = (mins: number): string => {
+    if (mins < 60) return `${mins}m`;
+    const h = Math.floor(mins / 60);
+    const m = mins % 60;
+    return m > 0 ? `${h}h ${m}m` : `${h}h`;
+  };
+
+  if (loading) {
+    return (
+      <div style={{ maxWidth: 800, margin: "0 auto", padding: 16, minHeight: "100vh", background: "#f8f9fa" }}>
+        <p style={{ textAlign: "center", color: "#888", padding: 40 }}>{t("common.loading")}</p>
+      </div>
+    );
+  }
+
+  if (!book) {
+    return (
+      <div style={{ maxWidth: 800, margin: "0 auto", padding: 16, minHeight: "100vh", background: "#f8f9fa" }}>
+        <p style={{ textAlign: "center", color: "#e74c3c", padding: 40 }}>Book not found</p>
+        <button onClick={() => navigate(`/groups/${groupId}`)} style={{ display: "block", margin: "0 auto" }}>← Back</button>
+      </div>
+    );
+  }
+
+  return (
+    <div style={{ maxWidth: 800, margin: "0 auto", padding: 16, minHeight: "100vh", background: "#f8f9fa" }}>
+      {/* Header */}
+      <header style={{ display: "flex", justifyContent: "space-between", alignItems: "center", padding: "16px 0", borderBottom: "1px solid #eee", marginBottom: 20 }}>
+        <div>
+          <h1 style={{ fontSize: 24, fontWeight: 700, color: "#1a1a2e", margin: 0 }}>{book.title}</h1>
+          <p style={{ margin: 4, fontSize: 13, color: "#888" }}>
+            {book.ebook.author && `by ${book.ebook.author} · `}
+            {book.ebook.page_count} chapters · {book.ebook.format.toUpperCase()}
+          </p>
+        </div>
+        <button onClick={() => navigate(`/groups/${groupId}`)} style={{ padding: "8px 16px", borderRadius: 6, border: "1px solid #ddd", background: "#fff", cursor: "pointer", fontSize: 14 }}>
+          ← {t("common.back")}
+        </button>
+      </header>
+
+      {error && (
+        <div style={{ background: "#fde8e8", padding: 12, borderRadius: 6, color: "#e74c3c", fontSize: 14, marginBottom: 16 }}>
+          {error}
+          <button onClick={() => setError(null)} style={{ marginLeft: 12, background: "none", border: "none", cursor: "pointer", fontWeight: 600 }}>✕</button>
+        </div>
+      )}
+
+      {/* Tabs */}
+      <div style={{ display: "flex", gap: 4, marginBottom: 20, background: "#eee", borderRadius: 8, padding: 4 }}>
+        {(["sections", "schedule", "progress"] as const).map((t) => (
+          <button
+            key={t}
+            onClick={() => setTab(t)}
+            style={{
+              flex: 1, padding: "10px 16px", borderRadius: 6, border: "none",
+              fontSize: 14, fontWeight: 600, cursor: "pointer",
+              background: tab === t ? "#fff" : "transparent",
+              color: tab === t ? "#1a1a2e" : "#888",
+              boxShadow: tab === t ? "0 1px 4px rgba(0,0,0,0.1)" : "none",
+            }}
+          >
+            {t === "sections" ? t("groups.sections") : t === "schedule" ? t("groups.schedule") : t("groups.progress")}
+          </button>
+        ))}
+      </div>
+
+      {/* Sections Tab */}
+      {tab === "sections" && (
+        <section>
+          <div style={{ display: "flex", justifyContent: "space-between", alignItems: "center", marginBottom: 16 }}>
+            <h2 style={{ fontSize: 18, fontWeight: 600, color: "#1a1a2e", margin: 0 }}>
+              {sections.length} {t("groups.sections")}
+            </h2>
+            <div style={{ display: "flex", gap: 8 }}>
+              <button
+                onClick={handleDetectSections}
+                style={{ padding: "8px 16px", borderRadius: 6, border: "none", background: "#1a1a2e", color: "#fff", fontSize: 13, fontWeight: 600, cursor: "pointer" }}
+              >
+                {t("groups.detectSections")}
+              </button>
+            </div>
+          </div>
+
+          {/* Merge controls */}
+          <div style={{ background: "#fff", padding: 16, borderRadius: 10, marginBottom: 12, boxShadow: "0 1px 4px rgba(0,0,0,0.06)" }}>
+            <div style={{ display: "flex", alignItems: "center", gap: 10, flexWrap: "wrap" }}>
+              <span style={{ fontSize: 14, fontWeight: 600, color: "#555" }}>{t("groups.mergeSections")}:</span>
+              <span style={{ fontSize: 13, color: "#888" }}>
+                {selectedForMerge.length === 0
+                  ? t("groups.selectSectionsHint")
+                  : `${selectedForMerge.length} selected`}
+              </span>
+              {selectedForMerge.length >= 2 && (
+                <button
+                  onClick={handleMerge}
+                  style={{ padding: "6px 14px", borderRadius: 6, border: "none", background: "#27ae60", color: "#fff", fontSize: 13, fontWeight: 600, cursor: "pointer" }}
+                >
+                  {t("groups.merge")}
+                </button>
+              )}
+              {selectedForMerge.length > 0 && (
+                <button
+                  onClick={() => setSelectedForMerge([])}
+                  style={{ padding: "6px 12px", borderRadius: 6, border: "1px solid #ddd", background: "#fff", fontSize: 13, cursor: "pointer" }}
+                >
+                  {t("groups.clear")}
+                </button>
+              )}
+            </div>
+          </div>
+
+          {sections.length === 0 ? (
+            <div style={{ textAlign: "center", padding: 40, color: "#888" }}>
+              <p style={{ fontSize: 16 }}>{t("groups.noSections")}</p>
+              <p style={{ fontSize: 14 }}>{t("groups.noSectionsHint")}</p>
+            </div>
+          ) : (
+            <div style={{ display: "flex", flexDirection: "column", gap: 10 }}>
+              {sections.map((section) => (
+                <div
+                  key={section.id}
+                  style={{
+                    background: selectedForMerge.includes(section.id) ? "#e8f0fe" : "#fff",
+                    border: selectedForMerge.includes(section.id) ? "2px solid #1a1a2e" : "1px solid #eee",
+                    padding: 16, borderRadius: 10, cursor: "pointer",
+                    boxShadow: "0 1px 4px rgba(0,0,0,0.06)",
+                    transition: "all 0.15s",
+                  }}
+                  onClick={() => toggleMergeSelect(section.id)}
+                >
+                  <div style={{ display: "flex", justifyContent: "space-between", alignItems: "flex-start" }}>
+                    <div style={{ flex: 1 }}>
+                      <div style={{ display: "flex", alignItems: "center", gap: 8 }}>
+                        <span style={{
+                          background: "#1a1a2e", color: "#fff", borderRadius: 20,
+                          width: 26, height: 26, display: "flex", alignItems: "center", justifyContent: "center",
+                          fontSize: 13, fontWeight: 700, flexShrink: 0,
+                        }}>
+                          {section.order}
+                        </span>
+                        <h3 style={{ margin: 0, fontSize: 15, fontWeight: 600, color: "#1a1a2e" }}>{section.title}</h3>
+                      </div>
+                      <p style={{ margin: "6px 0 0 34px", fontSize: 13, color: "#888" }}>
+                        Ch. {section.start_chapter_index}–{section.end_chapter_index - 1} · ~{formatMinutes(section.estimated_reading_minutes)} reading time
+                      </p>
+                    </div>
+                    <button
+                      onClick={(e) => {
+                        e.stopPropagation();
+                        setSplitSectionId(splitSectionId === section.id ? null : section.id);
+                      }}
+                      style={{
+                        padding: "4px 10px", borderRadius: 4, border: "1px solid #ddd",
+                        background: splitSectionId === section.id ? "#1a1a2e" : "#fff",
+                        color: splitSectionId === section.id ? "#fff" : "#666",
+                        fontSize: 12, cursor: "pointer", flexShrink: 0,
+                      }}
+                    >
+                      {t("groups.split")}
+                    </button>
+                  </div>
+                  {splitSectionId === section.id && (
+                    <div
+                      style={{ marginTop: 10, padding: 10, background: "#f8f9fa", borderRadius: 6, display: "flex", alignItems: "center", gap: 8 }}
+                      onClick={(e) => e.stopPropagation()}
+                    >
+                      <span style={{ fontSize: 13 }}>{t("groups.splitInto")}</span>
+                      <input
+                        type="number"
+                        value={splitAt}
+                        min={2}
+                        max={10}
+                        onChange={(e) => setSplitAt(Number(e.target.value))}
+                        style={{ width: 50, padding: "4px 8px", borderRadius: 4, border: "1px solid #ddd", fontSize: 13, textAlign: "center" }}
+                      />
+                      <span style={{ fontSize: 13 }}>{t("groups.parts")}</span>
+                      <button
+                        onClick={handleSplit}
+                        style={{ padding: "4px 12px", borderRadius: 4, border: "none", background: "#1a1a2e", color: "#fff", fontSize: 12, cursor: "pointer" }}
+                      >
+                        {t("groups.splitBtn")}
+                      </button>
+                    </div>
+                  )}
+                </div>
+              ))}
+            </div>
+          )}
+        </section>
+      )}
+
+      {/* Schedule Tab */}
+      {tab === "schedule" && (
+        <section>
+          <div style={{ display: "flex", justifyContent: "space-between", alignItems: "center", marginBottom: 16 }}>
+            <h2 style={{ fontSize: 18, fontWeight: 600, color: "#1a1a2e", margin: 0 }}>
+              {t("groups.readingSchedule")}
+            </h2>
+            <button
+              onClick={handleGenerateSchedule}
+              style={{ padding: "8px 16px", borderRadius: 6, border: "none", background: "#1a1a2e", color: "#fff", fontSize: 13, fontWeight: 600, cursor: "pointer" }}
+            >
+              {t("groups.generateSchedule")}
+            </button>
+          </div>
+
+          {schedules.length === 0 ? (
+            <div style={{ textAlign: "center", padding: 40, color: "#888" }}>
+              <p style={{ fontSize: 16 }}>{t("groups.noSchedule")}</p>
+              <p style={{ fontSize: 14 }}>{t("groups.noScheduleHint")}</p>
+            </div>
+          ) : (
+            <div style={{ display: "flex", flexDirection: "column", gap: 16 }}>
+              {schedules.map((s) => (
+                <div
+                  key={s.id}
+                  style={{ background: "#fff", padding: 20, borderRadius: 12, boxShadow: "0 2px 8px rgba(0,0,0,0.06)" }}
+                >
+                  <div style={{ display: "flex", justifyContent: "space-between", alignItems: "center", marginBottom: 12 }}>
+                    <div>
+                      <h3 style={{ margin: 0, fontSize: 17, fontWeight: 700, color: "#1a1a2e" }}>
+                        {t("groups.meeting")} {s.meeting_number}
+                      </h3>
+                      <p style={{ margin: "4px 0 0", fontSize: 13, color: "#888" }}>
+                        Week of {new Date(s.week_date).toLocaleDateString("en-US", { month: "long", day: "numeric", year: "numeric" })}
+                      </p>
+                    </div>
+                    <span style={{
+                      background: "#f0f0f0", padding: "6px 12px", borderRadius: 20,
+                      fontSize: 13, fontWeight: 600, color: "#555",
+                    }}>
+                      {s.section_details.reduce((sum, sec) => sum + sec.estimated_reading_minutes, 0) > 0
+                        ? `~${formatMinutes(s.section_details.reduce((sum, sec) => sum + sec.estimated_reading_minutes, 0))}`
+                        : ""}
+                    </span>
+                  </div>
+                  <div style={{ display: "flex", flexDirection: "column", gap: 6 }}>
+                    {s.section_details.map((sec) => (
+                      <div
+                        key={sec.id}
+                        style={{
+                          display: "flex", alignItems: "center", gap: 10, padding: "8px 12px",
+                          background: "#f8f9fa", borderRadius: 6, fontSize: 14,
+                        }}
+                      >
+                        <span style={{
+                          background: "#1a1a2e", color: "#fff", borderRadius: 12,
+                          width: 22, height: 22, display: "flex", alignItems: "center", justifyContent: "center",
+                          fontSize: 11, fontWeight: 700, flexShrink: 0,
+                        }}>
+                          {sec.order}
+                        </span>
+                        <span style={{ flex: 1 }}>{sec.title}</span>
+                        <span style={{ fontSize: 12, color: "#999" }}>{formatMinutes(sec.estimated_reading_minutes)}</span>
+                      </div>
+                    ))}
+                  </div>
+                </div>
+              ))}
+            </div>
+          )}
+        </section>
+      )}
+
+      {/* Progress Tab */}
+      {tab === "progress" && (
+        <section>
+          <h2 style={{ fontSize: 18, fontWeight: 600, color: "#1a1a2e", margin: "0 0 16px" }}>
+            {t("groups.memberProgress")}
+          </h2>
+          {progress.length === 0 ? (
+            <div style={{ textAlign: "center", padding: 40, color: "#888" }}>
+              <p style={{ fontSize: 16 }}>{t("groups.noProgress")}</p>
+              <p style={{ fontSize: 14 }}>{t("groups.noProgressHint")}</p>
+            </div>
+          ) : (
+            <div style={{ display: "flex", flexDirection: "column", gap: 10 }}>
+              {progress.map((p) => {
+                const totalSections = sections.length;
+                const completed = p.completed_sections.length;
+                const pct = totalSections > 0 ? Math.round((completed / totalSections) * 100) : 0;
+                return (
+                  <div
+                    key={p.id}
+                    style={{ background: "#fff", padding: 16, borderRadius: 10, boxShadow: "0 1px 4px rgba(0,0,0,0.06)" }}
+                  >
+                    <div style={{ display: "flex", justifyContent: "space-between", alignItems: "center", marginBottom: 8 }}>
+                      <span style={{ fontSize: 15, fontWeight: 600 }}>{p.user_email}</span>
+                      <span style={{ fontSize: 13, color: "#888" }}>{completed}/{totalSections} · {pct}%</span>
+                    </div>
+                    <div style={{ height: 6, background: "#eee", borderRadius: 3, overflow: "hidden" }}>
+                      <div
+                        style={{
+                          height: "100%", borderRadius: 3,
+                          background: "linear-gradient(90deg, #27ae60, #2ecc71)",
+                          width: `${pct}%`, transition: "width 0.3s",
+                        }}
+                      />
+                    </div>
+                    {p.current_section_title && (
+                      <p style={{ margin: "8px 0 0", fontSize: 13, color: "#888" }}>
+                        Currently: {p.current_section_title}
+                      </p>
+                    )}
+                  </div>
+                );
+              })}
+            </div>
+          )}
+        </section>
+      )}
+    </div>
+  );
+}
@@ -0,0 +1,300 @@
+import React, { useCallback, useEffect, useState } from "react";
+import { useNavigate, useParams } from "react-router-dom";
+import { useTranslation } from "react-i18n-lite";
+import { groupsApi } from "../api/groups";
+import { booksApi } from "../api/books";
+import { getApiErrorMessage } from "../api/errors";
+import type { ReadingGroupDetail, GroupBook, GroupBookDetail } from "../types/group";
+import type { EBookListItem } from "../types/book";
+
+export function GroupDetailPage() {
+  const { t } = useTranslation();
+  const navigate = useNavigate();
+  const { groupId } = useParams<{ groupId: string }>();
+  const [group, setGroup] = useState<ReadingGroupDetail | null>(null);
+  const [books, setBooks] = useState<GroupBook[]>([]);
+  const [loading, setLoading] = useState(true);
+  const [error, setError] = useState<string | null>(null);
+
+  // Upload state
+  const [showUpload, setShowUpload] = useState(false);
+  const [ebooks, setEbooks] = useState<EBookListItem[]>([]);
+  const [selectedEbookId, setSelectedEbookId] = useState<number | null>(null);
+  const [uploading, setUploading] = useState(false);
+
+  // Add member state
+  const [showAddMember, setShowAddMember] = useState(false);
+  const [memberEmail, setMemberEmail] = useState("");
+  const [adding, setAdding] = useState(false);
+
+  const id = Number(groupId);
+
+  const loadData = useCallback(async () => {
+    if (!id) return;
+    setLoading(true);
+    try {
+      const [groupData, bookData] = await Promise.all([
+        groupsApi.getGroup(id),
+        groupsApi.listGroupBooks(id),
+      ]);
+      setGroup(groupData);
+      setBooks(bookData);
+    } catch (err) {
+      setError(getApiErrorMessage(err, "Failed to load group"));
+    } finally {
+      setLoading(false);
+    }
+  }, [id]);
+
+  useEffect(() => {
+    loadData();
+  }, [loadData]);
+
+  const handleUploadClick = async () => {
+    setShowUpload(true);
+    try {
+      const ebookList = await booksApi.getEBooks();
+      setEbooks(ebookList.filter((e) => e.format === "epub"));
+    } catch {
+      // Ebook list fetch failed silently
+    }
+  };
+
+  const handleUpload = async () => {
+    if (!selectedEbookId || !id) return;
+    setUploading(true);
+    try {
+      const created = await groupsApi.createGroupBook(id, { ebook_id: selectedEbookId });
+      setShowUpload(false);
+      setSelectedEbookId(null);
+      await loadData();
+    } catch (err) {
+      setError(getApiErrorMessage(err, "Failed to upload book to group"));
+    } finally {
+      setUploading(false);
+    }
+  };
+
+  const handleAddMember = async (e: React.FormEvent) => {
+    e.preventDefault();
+    if (!memberEmail.trim() || !id) return;
+    setAdding(true);
+    try {
+      // Note: In a real implementation, we'd look up user by email.
+      // For now this requires user_id. Email lookup would be an enhancement.
+      await groupsApi.addMember(id, { user_id: Number(memberEmail) });
+      setShowAddMember(false);
+      setMemberEmail("");
+      await loadData();
+    } catch (err) {
+      setError(getApiErrorMessage(err, "Failed to add member. Please use a valid user ID."));
+    } finally {
+      setAdding(false);
+    }
+  };
+
+  const handleRemoveMember = async (userId: number) => {
+    if (!id) return;
+    try {
+      await groupsApi.removeMember(id, { user_id: userId });
+      await loadData();
+    } catch (err) {
+      setError(getApiErrorMessage(err, "Failed to remove member"));
+    }
+  };
+
+  if (loading) {
+    return (
+      <div style={{ maxWidth: 700, margin: "0 auto", padding: 16, minHeight: "100vh", background: "#f8f9fa" }}>
+        <p style={{ textAlign: "center", color: "#888", padding: 40 }}>{t("common.loading")}</p>
+      </div>
+    );
+  }
+
+  if (!group) {
+    return (
+      <div style={{ maxWidth: 700, margin: "0 auto", padding: 16, minHeight: "100vh", background: "#f8f9fa" }}>
+        <p style={{ textAlign: "center", color: "#e74c3c", padding: 40 }}>Group not found</p>
+        <button onClick={() => navigate("/groups")} style={{ display: "block", margin: "0 auto" }}>← Back to Groups</button>
+      </div>
+    );
+  }
+
+  return (
+    <div style={{ maxWidth: 700, margin: "0 auto", padding: 16, minHeight: "100vh", background: "#f8f9fa" }}>
+      <header style={{ display: "flex", justifyContent: "space-between", alignItems: "center", padding: "16px 0", borderBottom: "1px solid #eee", marginBottom: 20 }}>
+        <div>
+          <h1 style={{ fontSize: 24, fontWeight: 700, color: "#1a1a2e", margin: 0 }}>{group.name}</h1>
+          {group.description && <p style={{ margin: "4px 0 0", fontSize: 14, color: "#666" }}>{group.description}</p>}
+        </div>
+        <button onClick={() => navigate("/groups")} style={{ padding: "8px 16px", borderRadius: 6, border: "1px solid #ddd", background: "#fff", cursor: "pointer", fontSize: 14 }}>
+          ← {t("common.back")}
+        </button>
+      </header>
+
+      {error && (
+        <div style={{ background: "#fde8e8", padding: 12, borderRadius: 6, color: "#e74c3c", fontSize: 14, marginBottom: 16 }}>
+          {error}
+          <button onClick={() => setError(null)} style={{ marginLeft: 12, background: "none", border: "none", cursor: "pointer", fontWeight: 600 }}>✕</button>
+        </div>
+      )}
+
+      {/* Members Section */}
+      <section style={{ background: "#fff", padding: 20, borderRadius: 12, marginBottom: 20, boxShadow: "0 2px 8px rgba(0,0,0,0.06)" }}>
+        <div style={{ display: "flex", justifyContent: "space-between", alignItems: "center", marginBottom: 12 }}>
+          <h2 style={{ fontSize: 18, fontWeight: 600, color: "#1a1a2e", margin: 0 }}>{t("groups.members")} ({group.members.length})</h2>
+          <button
+            onClick={() => setShowAddMember(!showAddMember)}
+            style={{ padding: "6px 14px", borderRadius: 6, border: "1px solid #ddd", background: "#fff", cursor: "pointer", fontSize: 13 }}
+          >
+            {showAddMember ? t("groups.cancel") : `+ ${t("groups.addMember")}`}
+          </button>
+        </div>
+        {showAddMember && (
+          <form onSubmit={handleAddMember} style={{ display: "flex", gap: 8, marginBottom: 12 }}>
+            <input
+              type="text"
+              value={memberEmail}
+              onChange={(e) => setMemberEmail(e.target.value)}
+              placeholder={t("groups.memberIdPlaceholder")}
+              style={{ flex: 1, padding: "8px 12px", borderRadius: 6, border: "1px solid #ddd", fontSize: 14, outline: "none" }}
+            />
+            <button
+              type="submit"
+              disabled={adding}
+              style={{ padding: "8px 16px", borderRadius: 6, border: "none", background: "#1a1a2e", color: "#fff", fontSize: 14, cursor: "pointer", opacity: adding ? 0.6 : 1 }}
+            >
+              {t("groups.add")}
+            </button>
+          </form>
+        )}
+        <div style={{ display: "flex", flexDirection: "column", gap: 8 }}>
+          {group.members.map((m) => (
+            <div key={m.id} style={{ display: "flex", justifyContent: "space-between", alignItems: "center", padding: "8px 0", borderBottom: "1px solid #f0f0f0" }}>
+              <div>
+                <span style={{ fontSize: 14, fontWeight: 500 }}>{m.user_email}</span>
+                <span style={{ marginLeft: 8, fontSize: 12, color: m.role === "admin" ? "#e67e22" : "#999", background: m.role === "admin" ? "#fef3e2" : "#f0f0f0", padding: "2px 8px", borderRadius: 4 }}>
+                  {m.role}
+                </span>
+              </div>
+              {m.role !== "admin" && (
+                <button
+                  onClick={() => handleRemoveMember(m.user)}
+                  style={{ background: "none", border: "none", color: "#e74c3c", cursor: "pointer", fontSize: 13 }}
+                >
+                  {t("groups.remove")}
+                </button>
+              )}
+            </div>
+          ))}
+        </div>
+      </section>
+
+      {/* Books Section */}
+      <section style={{ background: "#fff", padding: 20, borderRadius: 12, boxShadow: "0 2px 8px rgba(0,0,0,0.06)" }}>
+        <div style={{ display: "flex", justifyContent: "space-between", alignItems: "center", marginBottom: 12 }}>
+          <h2 style={{ fontSize: 18, fontWeight: 600, color: "#1a1a2e", margin: 0 }}>{t("groups.books")} ({books.length})</h2>
+          <button
+            onClick={handleUploadClick}
+            style={{ padding: "8px 18px", borderRadius: 8, border: "none", background: "#1a1a2e", color: "#fff", fontSize: 14, fontWeight: 600, cursor: "pointer" }}
+          >
+            {t("groups.uploadEpub")}
+          </button>
+        </div>
+
+        {showUpload && (
+          <div style={{ background: "#f8f9fa", padding: 16, borderRadius: 8, marginBottom: 16 }}>
+            <h3 style={{ fontSize: 15, fontWeight: 600, margin: "0 0 12px" }}>{t("groups.selectEbook")}</h3>
+            {ebooks.length === 0 ? (
+              <div style={{ textAlign: "center", padding: 20, color: "#888" }}>
+                <p>{t("groups.noEpubBooks")}</p>
+                <button onClick={() => navigate("/add")} style={{ marginTop: 8, padding: "8px 16px", borderRadius: 6, border: "1px solid #ddd", background: "#fff", cursor: "pointer", fontSize: 13 }}>
+                  {t("groups.uploadFirst")}
+                </button>
+              </div>
+            ) : (
+              <div>
+                <div style={{ display: "flex", flexDirection: "column", gap: 8, marginBottom: 12, maxHeight: 200, overflowY: "auto" }}>
+                  {ebooks.map((eb) => (
+                    <label
+                      key={eb.id}
+                      style={{
+                        display: "flex", alignItems: "center", gap: 10, padding: "10px 12px",
+                        borderRadius: 8, cursor: "pointer", fontSize: 14,
+                        background: selectedEbookId === eb.id ? "#e8f0fe" : "#fff",
+                        border: selectedEbookId === eb.id ? "2px solid #1a1a2e" : "1px solid #eee",
+                      }}
+                    >
+                      <input
+                        type="radio"
+                        name="ebook"
+                        value={eb.id}
+                        checked={selectedEbookId === eb.id}
+                        onChange={() => setSelectedEbookId(eb.id)}
+                        style={{ accentColor: "#1a1a2e" }}
+                      />
+                      <div>
+                        <strong>{eb.title}</strong>
+                        {eb.author && <span style={{ color: "#888", marginLeft: 8 }}>by {eb.author}</span>}
+                        <span style={{ marginLeft: 8, fontSize: 12, color: "#aaa" }}>({eb.filename})</span>
+                      </div>
+                    </label>
+                  ))}
+                </div>
+                <div style={{ display: "flex", gap: 8 }}>
+                  <button
+                    onClick={handleUpload}
+                    disabled={!selectedEbookId || uploading}
+                    style={{ padding: "10px 20px", borderRadius: 8, border: "none", background: "#1a1a2e", color: "#fff", fontSize: 14, fontWeight: 600, cursor: uploading ? "default" : "pointer", opacity: uploading ? 0.6 : 1 }}
+                  >
+                    {uploading ? t("common.loading") : t("groups.confirmUpload")}
+                  </button>
+                  <button
+                    onClick={() => setShowUpload(false)}
+                    style={{ padding: "10px 20px", borderRadius: 8, border: "1px solid #ddd", background: "#fff", cursor: "pointer", fontSize: 14 }}
+                  >
+                    {t("groups.cancel")}
+                  </button>
+                </div>
+              </div>
+            )}
+          </div>
+        )}
+
+        {books.length === 0 ? (
+          <p style={{ textAlign: "center", color: "#888", padding: 30 }}>{t("groups.noBooks")}</p>
+        ) : (
+          <div style={{ display: "flex", flexDirection: "column", gap: 10 }}>
+            {books.map((book) => (
+              <div
+                key={book.id}
+                onClick={() => navigate(`/groups/${groupId}/books/${book.id}`)}
+                style={{
+                  display: "flex", justifyContent: "space-between", alignItems: "center",
+                  padding: 16, borderRadius: 10, cursor: "pointer", transition: "background 0.2s",
+                  background: book.status === "active" ? "#f0faf0" : "#fafafa",
+                  border: book.status === "active" ? "2px solid #27ae60" : "1px solid #eee",
+                }}
+                onMouseEnter={(e) => (e.currentTarget.style.background = book.status === "active" ? "#e8f5e9" : "#f5f5f5")}
+                onMouseLeave={(e) => (e.currentTarget.style.background = book.status === "active" ? "#f0faf0" : "#fafafa")}
+              >
+                <div>
+                  <h3 style={{ margin: 0, fontSize: 16, fontWeight: 600, color: "#1a1a2e" }}>
+                    {book.title}
+                    {book.status === "active" && (
+                      <span style={{ marginLeft: 8, fontSize: 11, color: "#27ae60", background: "#e8f5e9", padding: "2px 8px", borderRadius: 4 }}>Active</span>
+                    )}
+                  </h3>
+                  <p style={{ margin: "4px 0 0", fontSize: 13, color: "#888" }}>
+                    {book.section_count} sections · {book.ebook.page_count} chapters · uploaded by {book.uploaded_by_email}
+                  </p>
+                </div>
+                <span style={{ fontSize: 20, color: "#ccc" }}>→</span>
+              </div>
+            ))}
+          </div>
+        )}
+      </section>
+    </div>
+  );
+}
@@ -0,0 +1,162 @@
+import React, { useCallback, useEffect, useState } from "react";
+import { useNavigate } from "react-router-dom";
+import { useTranslation } from "react-i18n-lite";
+import { groupsApi } from "../api/groups";
+import { getApiErrorMessage } from "../api/errors";
+import type { ReadingGroup } from "../types/group";
+
+export function GroupsPage() {
+  const { t } = useTranslation();
+  const navigate = useNavigate();
+  const [groups, setGroups] = useState<ReadingGroup[]>([]);
+  const [loading, setLoading] = useState(true);
+  const [error, setError] = useState<string | null>(null);
+  const [showCreate, setShowCreate] = useState(false);
+  const [newName, setNewName] = useState("");
+  const [newDesc, setNewDesc] = useState("");
+  const [creating, setCreating] = useState(false);
+
+  const loadGroups = useCallback(async () => {
+    setLoading(true);
+    try {
+      const data = await groupsApi.listGroups();
+      setGroups(data);
+    } catch (err) {
+      setError(getApiErrorMessage(err, "Failed to load groups"));
+    } finally {
+      setLoading(false);
+    }
+  }, []);
+
+  useEffect(() => {
+    loadGroups();
+  }, [loadGroups]);
+
+  const handleCreate = async (e: React.FormEvent) => {
+    e.preventDefault();
+    if (!newName.trim()) return;
+    setCreating(true);
+    try {
+      await groupsApi.createGroup({ name: newName.trim(), description: newDesc.trim() });
+      setShowCreate(false);
+      setNewName("");
+      setNewDesc("");
+      await loadGroups();
+    } catch (err) {
+      setError(getApiErrorMessage(err, "Failed to create group"));
+    } finally {
+      setCreating(false);
+    }
+  };
+
+  return (
+    <div style={{ maxWidth: 700, margin: "0 auto", padding: 16, minHeight: "100vh", background: "#f8f9fa" }}>
+      <header style={{ display: "flex", justifyContent: "space-between", alignItems: "center", padding: "16px 0", borderBottom: "1px solid #eee", marginBottom: 20 }}>
+        <h1 style={{ fontSize: 24, fontWeight: 700, color: "#1a1a2e", margin: 0 }}>{t("groups.title")}</h1>
+        <button
+          type="button"
+          onClick={() => navigate("/")}
+          style={{ padding: "8px 16px", borderRadius: 6, border: "1px solid #ddd", background: "#fff", cursor: "pointer", fontSize: 14 }}
+        >
+          ← {t("common.back")}
+        </button>
+      </header>
+
+      {error && (
+        <div style={{ background: "#fde8e8", padding: 12, borderRadius: 6, color: "#e74c3c", fontSize: 14, marginBottom: 16 }}>
+          {error}
+          <button onClick={() => setError(null)} style={{ marginLeft: 12, background: "none", border: "none", cursor: "pointer", fontWeight: 600 }}>✕</button>
+        </div>
+      )}
+
+      <div style={{ marginBottom: 20 }}>
+        <button
+          type="button"
+          onClick={() => setShowCreate(!showCreate)}
+          style={{
+            padding: "12px 24px", borderRadius: 8, border: "none",
+            background: "#1a1a2e", color: "#fff", fontSize: 15, fontWeight: 600, cursor: "pointer",
+          }}
+        >
+          {showCreate ? t("groups.cancel") : t("groups.createGroup")}
+        </button>
+      </div>
+
+      {showCreate && (
+        <form onSubmit={handleCreate} style={{
+          background: "#fff", padding: 20, borderRadius: 12, marginBottom: 24,
+          boxShadow: "0 2px 8px rgba(0,0,0,0.06)", display: "flex", flexDirection: "column", gap: 14,
+        }}>
+          <div style={{ display: "flex", flexDirection: "column", gap: 6 }}>
+            <label style={{ fontSize: 14, fontWeight: 600, color: "#555" }}>{t("groups.groupName")}</label>
+            <input
+              type="text"
+              value={newName}
+              onChange={(e) => setNewName(e.target.value)}
+              placeholder={t("groups.groupNamePlaceholder")}
+              style={{ padding: "10px 12px", borderRadius: 6, border: "1px solid #ddd", fontSize: 16, outline: "none" }}
+              required
+            />
+          </div>
+          <div style={{ display: "flex", flexDirection: "column", gap: 6 }}>
+            <label style={{ fontSize: 14, fontWeight: 600, color: "#555" }}>{t("groups.description")} ({t("common.optional")})</label>
+            <textarea
+              value={newDesc}
+              onChange={(e) => setNewDesc(e.target.value)}
+              placeholder={t("groups.descriptionPlaceholder")}
+              rows={3}
+              style={{ padding: "10px 12px", borderRadius: 6, border: "1px solid #ddd", fontSize: 15, outline: "none", resize: "vertical" }}
+            />
+          </div>
+          <button
+            type="submit"
+            disabled={creating || !newName.trim()}
+            style={{
+              padding: "10px 20px", borderRadius: 8, border: "none",
+              background: "#1a1a2e", color: "#fff", fontSize: 15, fontWeight: 600,
+              cursor: creating ? "default" : "pointer", opacity: creating ? 0.6 : 1, alignSelf: "flex-start",
+            }}
+          >
+            {creating ? t("common.loading") : t("groups.create")}
+          </button>
+        </form>
+      )}
+
+      {loading ? (
+        <p style={{ textAlign: "center", color: "#888", padding: 40 }}>{t("common.loading")}</p>
+      ) : groups.length === 0 ? (
+        <div style={{ textAlign: "center", padding: 40, color: "#888" }}>
+          <p style={{ fontSize: 16, marginBottom: 8 }}>{t("groups.noGroups")}</p>
+          <p style={{ fontSize: 14 }}>{t("groups.noGroupsHint")}</p>
+        </div>
+      ) : (
+        <div style={{ display: "flex", flexDirection: "column", gap: 12 }}>
+          {groups.map((group) => (
+            <div
+              key={group.id}
+              onClick={() => navigate(`/groups/${group.id}`)}
+              style={{
+                background: "#fff", padding: 20, borderRadius: 12, cursor: "pointer",
+                boxShadow: "0 2px 8px rgba(0,0,0,0.06)", transition: "box-shadow 0.2s",
+                display: "flex", justifyContent: "space-between", alignItems: "center",
+              }}
+              onMouseEnter={(e) => (e.currentTarget.style.boxShadow = "0 4px 16px rgba(0,0,0,0.1)")}
+              onMouseLeave={(e) => (e.currentTarget.style.boxShadow = "0 2px 8px rgba(0,0,0,0.06)")}
+            >
+              <div>
+                <h3 style={{ margin: 0, fontSize: 18, fontWeight: 600, color: "#1a1a2e" }}>{group.name}</h3>
+                {group.description && (
+                  <p style={{ margin: "6px 0 0", fontSize: 14, color: "#666" }}>{group.description}</p>
+                )}
+                <p style={{ margin: "8px 0 0", fontSize: 13, color: "#999" }}>
+                  {group.member_count} {t("groups.members")} · {t("groups.admin")}: {group.admin_email}
+                </p>
+              </div>
+              <span style={{ fontSize: 20, color: "#ccc" }}>→</span>
+            </div>
+          ))}
+        </div>
+      )}
+    </div>
+  );
+}
@@ -1,601 +0,0 @@
-import React, { useCallback, useEffect, useState } from "react";
-import { useNavigate, useParams } from "react-router-dom";
-import { useTranslation } from "react-i18n-lite";
-import { schedulesApi } from "../api/books";
-import { booksApi } from "../api/books";
-import type {
-  BookChapter,
-  EBookListItem,
-  MeetingSection,
-  ReadingSchedule,
-} from "../types/book";
-import { useMediaQuery, BREAKPOINTS } from "../hooks/useMediaQuery";
-
-/* ---- drag-and-drop types ---- */
-interface DragData {
-  chapterId: number;
-  sourceMeetingId: number | null; // null = unassigned
-}
-
-function formatTime(minutes: number): string {
-  if (minutes < 60) return `${minutes} min`;
-  const h = Math.floor(minutes / 60);
-  const m = minutes % 60;
-  return m > 0 ? `${h}h ${m}m` : `${h}h`;
-}
-
-export function RecommendationPage() {
-  const { t } = useTranslation();
-  const { ebookId } = useParams<{ ebookId: string }>();
-  const navigate = useNavigate();
-  const isMobile = useMediaQuery(BREAKPOINTS.md);
-
-  const [ebook, setEbook] = useState<EBookListItem | null>(null);
-  const [schedule, setSchedule] = useState<ReadingSchedule | null>(null);
-  const [loading, setLoading] = useState(true);
-  const [generating, setGenerating] = useState(false);
-  const [error, setError] = useState<string | null>(null);
-  const [draggedChapter, setDraggedChapter] = useState<DragData | null>(null);
-  const [dropTarget, setDropTarget] = useState<number | null>(null);
-
-  const bookId = Number(ebookId);
-  const validId = !Number.isNaN(bookId);
-
-  const loadData = useCallback(async () => {
-    if (!validId) {
-      setError("Invalid ebook ID.");
-      setLoading(false);
-      return;
-    }
-    setLoading(true);
-    setError(null);
-    try {
-      const [ebookData, schedules] = await Promise.all([
-        booksApi.getEBook(bookId),
-        schedulesApi.getSchedules(),
-      ]);
-      setEbook({
-        id: ebookData.id,
-        title: ebookData.title,
-        author: ebookData.author,
-        filename: ebookData.filename,
-        format: ebookData.format,
-        page_count: ebookData.page_count,
-        cover_image:
-          typeof ebookData.cover_image === "string" ? ebookData.cover_image : null,
-        created_at: ebookData.created_at,
-        progress: ebookData.progress?.current_position ?? null,
-        started: ebookData.progress != null,
-      });
-      const existing = schedules.find((s) => s.ebook === bookId);
-      setSchedule(existing ?? null);
-    } catch (err) {
-      setError(err instanceof Error ? err.message : "Failed to load data.");
-    } finally {
-      setLoading(false);
-    }
-  }, [bookId, validId]);
-
-  useEffect(() => {
-    void loadData();
-  }, [loadData]);
-
-  const handleGenerate = useCallback(async () => {
-    if (!validId) return;
-    setGenerating(true);
-    setError(null);
-    try {
-      const newSchedule = await schedulesApi.generateRecommendations({
-        ebook_id: bookId,
-        meeting_count: 4,
-      });
-      setSchedule(newSchedule);
-    } catch (err) {
-      setError(err instanceof Error ? err.message : "Failed to generate recommendations.");
-    } finally {
-      setGenerating(false);
-    }
-  }, [bookId, validId]);
-
-  const handleRegenerate = useCallback(async () => {
-    if (!schedule) return;
-    setGenerating(true);
-    setError(null);
-    try {
-      const updated = await schedulesApi.regenerateRecommendations(schedule.id);
-      setSchedule(updated);
-    } catch (err) {
-      setError(err instanceof Error ? err.message : "Failed to regenerate recommendations.");
-    } finally {
-      setGenerating(false);
-    }
-  }, [schedule]);
-
-  const handleConfirm = useCallback(async () => {
-    if (!schedule) return;
-    setError(null);
-    try {
-      const updated = await schedulesApi.confirmSchedule(schedule.id);
-      setSchedule(updated);
-    } catch (err) {
-      setError(err instanceof Error ? err.message : "Failed to confirm schedule.");
-    }
-  }, [schedule]);
-
-  /* ---- drag-and-drop handlers ---- */
-  const handleDragStart = useCallback(
-    (chapterId: number, sourceMeetingId: number | null) => (e: React.DragEvent) => {
-      setDraggedChapter({ chapterId, sourceMeetingId });
-      e.dataTransfer.effectAllowed = "move";
-      e.dataTransfer.setData("text/plain", String(chapterId));
-    },
-    [],
-  );
-
-  const handleDragOver = useCallback(
-    (targetMeetingId: number) => (e: React.DragEvent) => {
-      e.preventDefault();
-      e.dataTransfer.dropEffect = "move";
-      setDropTarget(targetMeetingId);
-    },
-    [],
-  );
-
-  const handleDragLeave = useCallback(() => {
-    setDropTarget(null);
-  }, []);
-
-  const handleDrop = useCallback(
-    async (targetMeetingId: number) => {
-      setDropTarget(null);
-      if (!draggedChapter || !schedule) return;
-
-      const { chapterId, sourceMeetingId } = draggedChapter;
-      setDraggedChapter(null);
-
-      // Same meeting — no-op
-      if (sourceMeetingId === targetMeetingId) return;
-
-      // Optimistically update UI
-      const updatedMeetings = schedule.meetings.map((m) => ({
-        ...m,
-        chapter_ids: [...m.chapter_ids],
-        chapters: [...m.chapters],
-      }));
-
-      // Remove from source
-      if (sourceMeetingId !== null) {
-        const source = updatedMeetings.find((m) => m.id === sourceMeetingId);
-        if (source) {
-          source.chapter_ids = source.chapter_ids.filter((id) => id !== chapterId);
-          source.chapters = source.chapters.filter((ch) => ch.id !== chapterId);
-        }
-      }
-
-      // Add to target
-      const target = updatedMeetings.find((m) => m.id === targetMeetingId);
-      if (target && !target.chapter_ids.includes(chapterId)) {
-        target.chapter_ids = [...target.chapter_ids, chapterId];
-        // Find chapter data
-        const allChapters = schedule.meetings.flatMap((m) => m.chapters);
-        const movedChapter = allChapters.find((ch) => ch.id === chapterId);
-        if (movedChapter) {
-          target.chapters = [...target.chapters, movedChapter];
-        }
-      }
-
-      setSchedule({ ...schedule, meetings: updatedMeetings });
-
-      // Persist to backend
-      try {
-        await schedulesApi.updateMeeting(schedule.id, targetMeetingId, {
-          chapter_ids: target?.chapter_ids ?? [],
-        });
-        if (sourceMeetingId !== null) {
-          const source = updatedMeetings.find((m) => m.id === sourceMeetingId);
-          if (source) {
-            await schedulesApi.updateMeeting(schedule.id, sourceMeetingId, {
-              chapter_ids: source.chapter_ids,
-            });
-          }
-        }
-      } catch (err) {
-        setError("Failed to save changes. Please try again.");
-        // Reload to reset
-        void loadData();
-      }
-    },
-    [draggedChapter, schedule, loadData],
-  );
-
-  const handleUnassignDrop = useCallback(
-    async () => {
-      setDropTarget(null);
-      if (!draggedChapter || !schedule) return;
-      const { chapterId, sourceMeetingId } = draggedChapter;
-      setDraggedChapter(null);
-
-      if (sourceMeetingId === null) return;
-
-      // Remove from source
-      const updatedMeetings = schedule.meetings.map((m) => ({
-        ...m,
-        chapter_ids: [...m.chapter_ids],
-        chapters: [...m.chapters],
-      }));
-      const source = updatedMeetings.find((m) => m.id === sourceMeetingId);
-      if (source) {
-        source.chapter_ids = source.chapter_ids.filter((id) => id !== chapterId);
-        source.chapters = source.chapters.filter((ch) => ch.id !== chapterId);
-      }
-
-      setSchedule({ ...schedule, meetings: updatedMeetings });
-
-      try {
-        await schedulesApi.updateMeeting(schedule.id, sourceMeetingId, {
-          chapter_ids: source?.chapter_ids ?? [],
-        });
-      } catch {
-        setError("Failed to save changes.");
-        void loadData();
-      }
-    },
-    [draggedChapter, schedule, loadData],
-  );
-
-  const handleDragEnd = useCallback(() => {
-    setDraggedChapter(null);
-    setDropTarget(null);
-  }, []);
-
-  /* ---- styles ---- */
-  const containerStyle: React.CSSProperties = {
-    maxWidth: 1200,
-    margin: "0 auto",
-    padding: isMobile ? 12 : 24,
-    minHeight: "100vh",
-    background: "#f8f9fa",
-  };
-
-  const headerStyle: React.CSSProperties = {
-    display: "flex",
-    alignItems: "center",
-    gap: 12,
-    marginBottom: 24,
-    flexWrap: "wrap",
-  };
-
-  const backBtnStyle: React.CSSProperties = {
-    padding: "8px 16px",
-    borderRadius: 8,
-    border: "1px solid #e5e7eb",
-    background: "#fff",
-    color: "#374151",
-    fontSize: 14,
-    cursor: "pointer",
-  };
-
-  const btnPrimaryStyle: React.CSSProperties = {
-    padding: "10px 24px",
-    borderRadius: 8,
-    border: "none",
-    background: "#4f46e5",
-    color: "#fff",
-    fontSize: 14,
-    fontWeight: 600,
-    cursor: "pointer",
-    opacity: generating ? 0.7 : 1,
-    minHeight: 44,
-  };
-
-  const confirmBtnStyle: React.CSSProperties = {
-    ...btnPrimaryStyle,
-    background: "#16a34a",
-  };
-
-  const meetingsGridStyle: React.CSSProperties = {
-    display: "grid",
-    gridTemplateColumns: isMobile
-      ? "1fr"
-      : `repeat(${schedule?.meeting_count ?? 4}, 1fr)`,
-    gap: 16,
-    marginTop: 16,
-  };
-
-  const meetingCardStyle = (isDropTarget: boolean): React.CSSProperties => ({
-    background: isDropTarget ? "#eef2ff" : "#fff",
-    borderRadius: 12,
-    border: `2px solid ${isDropTarget ? "#4f46e5" : "#e5e7eb"}`,
-    padding: 16,
-    minHeight: 200,
-    transition: "border-color 0.2s, background 0.2s",
-  });
-
-  const chapterChipStyle: React.CSSProperties = {
-    background: "#f3f4f6",
-    borderRadius: 8,
-    padding: "8px 12px",
-    marginBottom: 8,
-    cursor: "grab",
-    fontSize: 13,
-    color: "#374151",
-    border: "1px solid #e5e7eb",
-    userSelect: "none" as const,
-  };
-
-  /* ---- render ---- */
-
-  if (!validId) {
-    return (
-      <div style={containerStyle}>
-        <p style={{ color: "#ef4444" }}>Invalid ebook ID.</p>
-      </div>
-    );
-  }
-
-  if (loading) {
-    return (
-      <div style={containerStyle}>
-        <div style={{ display: "flex", justifyContent: "center", alignItems: "center", minHeight: 400 }}>
-          <p style={{ color: "#888" }}>{t("common.loading")}</p>
-        </div>
-      </div>
-    );
-  }
-
-  if (error) {
-    return (
-      <div style={containerStyle}>
-        <button onClick={() => navigate(-1)} style={backBtnStyle}>← Back</button>
-        <div style={{ textAlign: "center", padding: 60 }}>
-          <p style={{ color: "#ef4444", marginBottom: 16 }}>{error}</p>
-          <button onClick={() => void loadData()} style={btnPrimaryStyle}>
-            {t("common.retry")}
-          </button>
-        </div>
-      </div>
-    );
-  }
-
-  return (
-    <div style={containerStyle}>
-      {/* Header */}
-      <div style={headerStyle}>
-        <button onClick={() => navigate("/")} style={backBtnStyle}>
-          ← {isMobile ? "Library" : "Back to Library"}
-        </button>
-        <div style={{ flex: 1 }}>
-          <h1 style={{ fontSize: isMobile ? 18 : 24, margin: 0, color: "#1f2937" }}>
-            Reading Schedule
-          </h1>
-          {ebook && (
-            <p style={{ color: "#6b7280", fontSize: 14, margin: "4px 0 0" }}>
-              {ebook.title}{ebook.author ? ` — ${ebook.author}` : ""}
-            </p>
-          )}
-        </div>
-        {!schedule && (
-          <button onClick={handleGenerate} style={btnPrimaryStyle} disabled={generating}>
-            {generating ? "Generating..." : "Generate Recommendations"}
-          </button>
-        )}
-        {schedule && (
-          <div style={{ display: "flex", gap: 8, flexWrap: "wrap" }}>
-            <button onClick={handleRegenerate} style={btnPrimaryStyle} disabled={generating}>
-              {generating ? "Regenerating..." : "Regenerate"}
-            </button>
-            {!schedule.confirmed && (
-              <button onClick={handleConfirm} style={confirmBtnStyle}>
-                Confirm Schedule
-              </button>
-            )}
-          </div>
-        )}
-      </div>
-
-      {/* Status badge */}
-      {schedule && (
-        <div style={{ marginBottom: 16 }}>
-          <span style={{
-            padding: "4px 12px",
-            borderRadius: 999,
-            fontSize: 13,
-            fontWeight: 600,
-            background: schedule.confirmed ? "#dcfce7" : "#fef3c7",
-            color: schedule.confirmed ? "#16a34a" : "#b45309",
-          }}>
-            {schedule.confirmed ? "✓ Confirmed" : "Draft — drag chapters to adjust"}
-          </span>
-        </div>
-      )}
-
-      {/* No schedule yet */}
-      {!schedule && (
-        <div style={{ textAlign: "center", padding: "60px 16px" }}>
-          <div style={{ fontSize: 48, marginBottom: 16 }}>📅</div>
-          <h2 style={{ fontSize: 20, color: "#1f2937", marginBottom: 8 }}>
-            No Schedule Yet
-          </h2>
-          <p style={{ color: "#6b7280", marginBottom: 24, maxWidth: 400, margin: "0 auto 24px" }}>
-            Generate a reading schedule to split this book into balanced weekly assignments for your group.
-          </p>
-          <button onClick={handleGenerate} style={btnPrimaryStyle} disabled={generating}>
-            {generating ? "Generating..." : "Generate Recommendations"}
-          </button>
-        </div>
-      )}
-
-      {/* Schedule meetings */}
-      {schedule && (
-        <>
-          {/* Unassigned drop zone */}
-          <div
-            style={{
-              padding: "12px 16px",
-              background: dropTarget === null && draggedChapter ? "#fef2f2" : "#f9fafb",
-              borderRadius: 8,
-              border: `2px dashed ${dropTarget === null && draggedChapter ? "#ef4444" : "#d1d5db"}`,
-              marginBottom: 16,
-              textAlign: "center",
-              color: "#6b7280",
-              fontSize: 13,
-              minHeight: 44,
-              display: "flex",
-              alignItems: "center",
-              justifyContent: "center",
-              transition: "all 0.2s",
-            }}
-            onDragOver={(e) => { e.preventDefault(); e.dataTransfer.dropEffect = "move"; setDropTarget(null); }}
-            onDrop={handleUnassignDrop}
-            onDragLeave={() => setDropTarget(null)}
-          >
-            {dropTarget === null && draggedChapter
-              ? "Drop here to unassign"
-              : "Drag chapters here to unassign from meetings"}
-          </div>
-
-          {/* Meetings grid */}
-          <div style={meetingsGridStyle}>
-            {schedule.meetings.map((meeting, idx) => (
-              <MeetingColumn
-                key={meeting.id}
-                meeting={meeting}
-                index={idx}
-                isDropTarget={dropTarget === meeting.id}
-                isConfirmed={schedule.confirmed}
-                onDragStart={handleDragStart}
-                onDragOver={handleDragOver(meeting.id)}
-                onDragLeave={handleDragLeave}
-                onDrop={() => void handleDrop(meeting.id)}
-                onDragEnd={handleDragEnd}
-              />
-            ))}
-          </div>
-        </>
-      )}
-
-      {/* Drag overlay instruction */}
-      {draggedChapter && (
-        <div style={{
-          position: "fixed",
-          bottom: 24,
-          left: "50%",
-          transform: "translateX(-50%)",
-          background: "#1f2937",
-          color: "#fff",
-          padding: "12px 24px",
-          borderRadius: 12,
-          fontSize: 14,
-          boxShadow: "0 4px 16px rgba(0,0,0,0.2)",
-          zIndex: 999,
-        }}>
-          Drop the chapter into a meeting column
-        </div>
-      )}
-    </div>
-  );
-}
-
-/* ---- Meeting Column Sub-component ---- */
-
-interface MeetingColumnProps {
-  meeting: MeetingSection;
-  index: number;
-  isDropTarget: boolean;
-  isConfirmed: boolean;
-  onDragStart: (chapterId: number, sourceMeetingId: number | null) => (e: React.DragEvent) => void;
-  onDragOver: (e: React.DragEvent) => void;
-  onDragLeave: () => void;
-  onDrop: () => void;
-  onDragEnd: () => void;
-}
-
-function MeetingColumn({
-  meeting,
-  index,
-  isDropTarget,
-  isConfirmed,
-  onDragStart,
-  onDragOver,
-  onDragLeave,
-  onDrop,
-  onDragEnd,
-}: MeetingColumnProps) {
-  const chapterCount = meeting.chapter_ids.length;
-
-  const cardStyle: React.CSSProperties = {
-    background: isDropTarget ? "#eef2ff" : "#fff",
-    borderRadius: 12,
-    border: `2px solid ${isDropTarget ? "#4f46e5" : "#e5e7eb"}`,
-    overflow: "hidden",
-    transition: "border-color 0.2s, background 0.2s",
-  };
-
-  const headerStyle: React.CSSProperties = {
-    padding: "12px 16px",
-    background: "#f9fafb",
-    borderBottom: "1px solid #e5e7eb",
-  };
-
-  const bodyStyle: React.CSSProperties = {
-    padding: "12px 16px",
-    minHeight: 120,
-  };
-
-  return (
-    <div style={cardStyle}>
-      <div style={headerStyle}>
-        <div style={{ fontWeight: 700, color: "#1f2937", fontSize: 15, marginBottom: 4 }}>
-          Week {index + 1}
-        </div>
-        <div style={{ display: "flex", gap: 16, fontSize: 12, color: "#6b7280" }}>
-          <span>{chapterCount} {chapterCount === 1 ? "chapter" : "chapters"}</span>
-          <span>{formatTime(meeting.estimated_time_minutes)}</span>
-        </div>
-      </div>
-      <div
-        style={bodyStyle}
-        onDragOver={isConfirmed ? undefined : onDragOver}
-        onDragLeave={isConfirmed ? undefined : onDragLeave}
-        onDrop={isConfirmed ? undefined : onDrop}
-      >
-        {meeting.chapters.length === 0 && (
-          <div style={{
-            color: "#9ca3af",
-            fontSize: 13,
-            textAlign: "center",
-            padding: "20px 0",
-            fontStyle: "italic",
-          }}>
-            {isDropTarget ? "Drop here" : "No chapters assigned"}
-          </div>
-        )}
-        {meeting.chapters.map((chapter) => (
-          <div
-            key={`${meeting.id}-${chapter.id}`}
-            draggable={!isConfirmed}
-            onDragStart={isConfirmed ? undefined : onDragStart(chapter.id, meeting.id)}
-            onDragEnd={isConfirmed ? undefined : onDragEnd}
-            style={{
-              background: "#f3f4f6",
-              borderRadius: 8,
-              padding: "8px 12px",
-              marginBottom: 8,
-              cursor: isConfirmed ? "default" : "grab",
-              fontSize: 13,
-              color: "#374151",
-              border: "1px solid #e5e7eb",
-              userSelect: "none" as const,
-              opacity: isConfirmed ? 0.8 : 1,
-            }}
-          >
-            <div style={{ fontWeight: 600, marginBottom: 2 }}>{chapter.title}</div>
-            {chapter.href && (
-              <div style={{ fontSize: 11, color: "#9ca3af" }}>{chapter.href}</div>
-            )}
-          </div>
-        ))}
-      </div>
-    </div>
-  );
-}
@@ -102,27 +102,3 @@ export interface BookSearchParams {
  page?: number;
  page_size?: number;
 }
-
-export interface MeetingSection {
-  id: number;
-  meeting_index: number;
-  title: string;
-  estimated_time_minutes: number;
-  chapter_ids: number[];
-  chapters: BookChapter[];
-}
-
-export interface ReadingSchedule {
-  id: number;
-  ebook: number;
-  meeting_count: number;
-  confirmed: boolean;
-  meetings: MeetingSection[];
-  created_at: string;
-  updated_at: string;
-}
-
-export interface GenerateRecommendationsRequest {
-  ebook_id: number;
-  meeting_count?: number;
-}
@@ -0,0 +1,109 @@
+/** Types for reading groups, group books, sections, and schedules */
+
+export interface ReadingGroup {
+  id: number;
+  name: string;
+  description: string;
+  admin: number;
+  admin_email: string;
+  member_count: number;
+  created_at: string;
+  updated_at: string;
+}
+
+export interface ReadingGroupDetail {
+  id: number;
+  name: string;
+  description: string;
+  admin: number;
+  admin_email: string;
+  members: GroupMembership[];
+  created_at: string;
+  updated_at: string;
+}
+
+export interface GroupMembership {
+  id: number;
+  user: number;
+  user_email: string;
+  user_username: string;
+  role: "admin" | "member";
+  joined_at: string;
+}
+
+export interface GroupBook {
+  id: number;
+  title: string;
+  status: "active" | "replaced";
+  ebook: {
+    id: number;
+    title: string;
+    author: string;
+    filename: string;
+    format: string;
+    page_count: number;
+    file_size: number;
+    cover_image: string | null;
+    created_at: string;
+  };
+  uploaded_by: number;
+  uploaded_by_email: string;
+  section_count: number;
+  created_at: string;
+  updated_at: string;
+}
+
+export interface Section {
+  id: number;
+  title: string;
+  order: number;
+  start_chapter_index: number;
+  end_chapter_index: number;
+  estimated_reading_minutes: number;
+  created_at: string;
+}
+
+export interface GroupBookDetail extends GroupBook {
+  sections: Section[];
+  schedules: ReadingSchedule[];
+}
+
+export interface ReadingSchedule {
+  id: number;
+  meeting_number: number;
+  week_date: string;
+  section_ids: number[];
+  section_details: Section[];
+  created_at: string;
+}
+
+export interface MemberProgress {
+  id: number;
+  user: number;
+  user_email: string;
+  user_username: string;
+  current_section: number | null;
+  current_section_title: string | null;
+  completed_sections: number[];
+  updated_at: string;
+}
+
+export interface CreateGroupPayload {
+  name: string;
+  description?: string;
+}
+
+export interface AddMemberPayload {
+  user_id: number;
+}
+
+export interface CreateGroupBookPayload {
+  ebook_id: number;
+  title?: string;
+}
+
+export interface AdjustSectionsPayload {
+  operation: "merge" | "split";
+  section_ids: number[];
+  split_at?: number;
+}
@@ -216,3 +216,47 @@ export interface ApiError {
  detail?: string;
  [key: string]: unknown;
 }
+
+// ---- Reading Groups ----
+
+export interface ReadingGroup {
+  id: number;
+  name: string;
+  description: string;
+  admin: number;
+  admin_email: string;
+  member_count: number;
+  created_at: string;
+  updated_at: string;
+}
+
+export interface GroupMembership {
+  id: number;
+  user: number;
+  user_email: string;
+  user_username: string;
+  role: "admin" | "member";
+  joined_at: string;
+}
+
+export interface GroupBookSummary {
+  id: number;
+  title: string;
+  status: "active" | "replaced";
+  section_count: number;
+  created_at: string;
+}
+
+export interface SectionSummary {
+  id: number;
+  title: string;
+  order: number;
+  estimated_reading_minutes: number;
+}
+
+export interface ReadingScheduleEntry {
+  id: number;
+  meeting_number: number;
+  week_date: string;
+  section_ids: number[];
+}
@@ -114,4 +114,14 @@ 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}/`,
+    books: (groupId: number) => `/api/groups/${groupId}/books/`,
+    bookDetail: (groupId: number, bookId: number) => `/api/groups/${groupId}/books/${bookId}/`,
+    detectSections: (groupId: number, bookId: number) => `/api/groups/${groupId}/books/${bookId}/detect-sections/`,
+    adjustSections: (groupId: number, bookId: number) => `/api/groups/${groupId}/books/${bookId}/adjust-sections/`,
+    schedule: (groupId: number, bookId: number) => `/api/groups/${groupId}/books/${bookId}/schedule/`,
+    progress: (groupId: number, bookId: number) => `/api/groups/${groupId}/books/${bookId}/progress/`,
+  },
 } as const;