Add watches: follow pages and ponds with auto-watch preferences (#93)

New watches table (polymorphic target, unique per user+target; page purge
removes its rows via the trash service, and the list endpoint drops
targets the user can no longer read). Endpoints: idempotent PUT/DELETE
/watches/{page|pond}/:id gated by read access (404 hides the target),
GET state for the header toggles, and GET /users/me/watches resolving
names and links. Auto-watch hooks: creating a page and commenting
subscribe the actor, each behind a new user preference
(autoWatchOwnPages / autoWatchOnComment, default on) editable via the
profile PATCH and surfaced as checkboxes in the settings. UI: watch
toggle on the page header and the pond settings header, watch list with
unwatch in the account settings; new watches i18n namespace (de+en).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EwZ4jR4KFAPvpjWevfUGX1

apps/api/prisma/migrations/20260711230000_watches/migration.sql

@@ -0,0 +1,23 @@
+-- Watches + auto-watch preferences (issue #93).
+
+ALTER TABLE "users" ADD COLUMN "auto_watch_own_pages" BOOLEAN NOT NULL DEFAULT true;
+ALTER TABLE "users" ADD COLUMN "auto_watch_on_comment" BOOLEAN NOT NULL DEFAULT true;
+
+CREATE TYPE "WatchTargetType" AS ENUM ('PAGE', 'POND');
+
+CREATE TABLE "watches" (
+    "id" TEXT NOT NULL,
+    "user_id" TEXT NOT NULL,
+    "target_type" "WatchTargetType" NOT NULL,
+    "target_id" TEXT NOT NULL,
+    "created_at" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+
+    CONSTRAINT "watches_pkey" PRIMARY KEY ("id")
+);
+
+CREATE UNIQUE INDEX "watches_user_id_target_type_target_id_key"
+    ON "watches"("user_id", "target_type", "target_id");
+CREATE INDEX "watches_target_type_target_id_idx" ON "watches"("target_type", "target_id");
+
+ALTER TABLE "watches" ADD CONSTRAINT "watches_user_id_fkey"
+    FOREIGN KEY ("user_id") REFERENCES "users"("id") ON DELETE CASCADE ON UPDATE CASCADE;

apps/api/prisma/schema.prisma

@@ -37,6 +37,9 @@ model User {
   displayName     String     @map("display_name")
   locale          String     @default("en")
   isSiteAdmin     Boolean    @default(false) @map("is_site_admin")
+  /// Auto-watch preferences (issue #93): watch pages I create / comment on.
+  autoWatchOwnPages  Boolean @default(true) @map("auto_watch_own_pages")
+  autoWatchOnComment Boolean @default(true) @map("auto_watch_on_comment")
   status          UserStatus @default(PENDING_VERIFICATION)
   emailVerifiedAt DateTime?  @map("email_verified_at")
   createdAt       DateTime   @default(now()) @map("created_at")
@@ -51,6 +54,7 @@ model User {
   conversionJobs  ConversionJob[]
   auditEntries    AuditEntry[]
   comments        Comment[]
+  watches         Watch[]
 
   @@map("users")
 }
@@ -110,6 +114,29 @@ model Comment {
   @@map("comments")
 }
 
+enum WatchTargetType {
+  PAGE
+  POND
+}
+
+/// Explicit subscription (issue #93, data-model.md §watches): the target is
+/// polymorphic (no FK) — page purge removes its watches via the trash
+/// service, and the list endpoint filters targets the user can no longer
+/// read, so stale rows are invisible and harmless.
+model Watch {
+  id         String          @id @default(uuid())
+  userId     String          @map("user_id")
+  targetType WatchTargetType @map("target_type")
+  targetId   String          @map("target_id")
+  createdAt  DateTime        @default(now()) @map("created_at")
+
+  user User @relation(fields: [userId], references: [id], onDelete: Cascade)
+
+  @@unique([userId, targetType, targetId])
+  @@index([targetType, targetId])
+  @@map("watches")
+}
+
 enum PondType {
   PERSONAL
   SHARED

apps/api/src/app.module.ts

@@ -31,6 +31,7 @@ import { SettingsModule } from './settings/settings.module';
 import { SetupModule } from './setup/setup.module';
 import { TrashModule } from './trash/trash.module';
 import { UsersModule } from './users/users.module';
+import { WatchesModule } from './watches/watches.module';
 import { VersionsModule } from './versions/versions.module';
 
 @Module({
@@ -49,6 +50,7 @@ import { VersionsModule } from './versions/versions.module';
     PondsModule,
     PagesModule,
     CommentsModule,
+    WatchesModule,
     FilesModule,
     TrashModule,
     CompactionModule,

apps/api/src/auth/auth.guard.ts

@@ -40,6 +40,8 @@ export function toCurrentUser(user: User): CurrentUserShape {
     displayName: user.displayName,
     locale: user.locale === 'de' ? 'de' : 'en',
     isSiteAdmin: user.isSiteAdmin,
+    autoWatchOwnPages: user.autoWatchOwnPages,
+    autoWatchOnComment: user.autoWatchOnComment,
   };
 }
 

apps/api/src/comments/comments.module.ts

@@ -1,12 +1,13 @@
 import { Module } from '@nestjs/common';
 
 import { PermissionsModule } from '../permissions/permissions.module';
+import { WatchesModule } from '../watches/watches.module';
 
 import { CommentsController } from './comments.controller';
 import { CommentsService } from './comments.service';
 
 @Module({
-  imports: [PermissionsModule],
+  imports: [PermissionsModule, WatchesModule],
   controllers: [CommentsController],
   providers: [CommentsService],
   exports: [CommentsService],

apps/api/src/comments/comments.service.ts

@@ -19,6 +19,7 @@ import { Comment, Page, User } from '@prisma/client';
 
 import { PermissionService } from '../permissions/permission.service';
 import { PrismaService } from '../prisma/prisma.service';
+import { WatchesService } from '../watches/watches.service';
 
 type CommentWithAuthor = Comment & {
   author: { id: string; username: string; displayName: string } | null;
@@ -36,6 +37,7 @@ export class CommentsService {
   constructor(
     private readonly prisma: PrismaService,
     private readonly permissions: PermissionService,
+    private readonly watches: WatchesService,
   ) {}
 
   /** Comments live on live pages only — trash hides them (ADR 0013). */
@@ -141,6 +143,9 @@ export class CommentsService {
       },
       include: { author: { select: { id: true, username: true, displayName: true } } },
     });
+    // Commenting subscribes the author to the page (issue #93) —
+    // preference-gated, never fatal for the comment itself.
+    await this.watches.autoWatchPage(user, pageId, 'comment').catch(() => {});
     return CommentsService.viewOf(created as CommentWithAuthor);
   }
 

apps/api/src/pages/pages.module.ts

@@ -1,6 +1,7 @@
 import { Module } from '@nestjs/common';
 
 import { PondsModule } from '../ponds/ponds.module';
+import { WatchesModule } from '../watches/watches.module';
 import { SearchModule } from '../search/search.module';
 
 import { PagesController } from './pages.controller';
@@ -8,7 +9,7 @@ import { PagesService } from './pages.service';
 import { PluginApiController } from './plugin-api.controller';
 
 @Module({
-  imports: [PondsModule, SearchModule],
+  imports: [PondsModule, SearchModule, WatchesModule],
   controllers: [PagesController, PluginApiController],
   providers: [PagesService],
   exports: [PagesService],

apps/api/src/pages/pages.service.ts

@@ -21,6 +21,7 @@ import { PinoLogger } from 'nestjs-pino';
 import { AppConfig } from '../config/app-config.service';
 import { PermissionService } from '../permissions/permission.service';
 import { PrismaService } from '../prisma/prisma.service';
+import { WatchesService } from '../watches/watches.service';
 import { SearchProvider } from '../search/search.provider';
 import { evenlySpacedKeys, nextKeyOrRebalance } from './sort-key';
 import { deriveContent, DerivedPageContent, emptyPageState } from './yjs-content';
@@ -49,6 +50,7 @@ export class PagesService {
     private readonly logger: PinoLogger,
     private readonly config: AppConfig,
     private readonly search: SearchProvider,
+    private readonly watches: WatchesService,
   ) {
     this.logger.setContext(PagesService.name);
   }
@@ -153,6 +155,8 @@ export class PagesService {
 
   async create(user: User, pondId: string, input: CreatePageInput): Promise<PageView> {
     const page = await this.insertPage(user, pondId, input.title, emptyPageState());
+    // Auto-watch own pages (issue #93) — preference-gated, never fatal.
+    await this.watches.autoWatchPage(user, page.id, 'ownPage').catch(() => {});
     return this.viewOf(page);
   }
 

apps/api/src/trash/trash.module.ts

@@ -5,6 +5,7 @@ import { FilesModule } from '../files/files.module';
 import { PagesModule } from '../pages/pages.module';
 import { PondsModule } from '../ponds/ponds.module';
 import { QuotasModule } from '../quotas/quotas.module';
+import { WatchesModule } from '../watches/watches.module';
 import { SchedulerModule } from '../scheduler/scheduler.module';
 import { SchedulerService } from '../scheduler/scheduler.service';
 
@@ -15,7 +16,15 @@ import { TrashService } from './trash.service';
 const TRASH_PURGE_CADENCE_SECONDS = 24 * 60 * 60;
 
 @Module({
-  imports: [CommonModule, PondsModule, QuotasModule, FilesModule, PagesModule, SchedulerModule],
+  imports: [
+    CommonModule,
+    PondsModule,
+    QuotasModule,
+    FilesModule,
+    PagesModule,
+    SchedulerModule,
+    WatchesModule,
+  ],
   controllers: [TrashController],
   providers: [TrashService],
 })

apps/api/src/trash/trash.service.ts

@@ -7,6 +7,7 @@ import { ClockService } from '../common/clock.service';
 import { PagesService } from '../pages/pages.service';
 import { PermissionService } from '../permissions/permission.service';
 import { PrismaService } from '../prisma/prisma.service';
+import { WatchesService } from '../watches/watches.service';
 import { QuotaService } from '../quotas/quota.service';
 import { InstanceSettingsService } from '../settings/instance-settings.service';
 import { FileStorageService } from '../files/file-storage.service';
@@ -30,6 +31,7 @@ export class TrashService {
     private readonly quotas: QuotaService,
     private readonly storage: FileStorageService,
     private readonly clock: ClockService,
+    private readonly watches: WatchesService,
     private readonly logger: PinoLogger,
   ) {
     this.logger.setContext(TrashService.name);
@@ -102,6 +104,7 @@ export class TrashService {
     await this.prisma.attachment.deleteMany({ where: { pageId } });
     await this.prisma.pageContentCache.deleteMany({ where: { pageId } });
     await this.prisma.pageUpdate.deleteMany({ where: { pageId } });
+    await this.watches.removeForPage(pageId);
     await this.prisma.page.delete({ where: { id: pageId } });
     this.logger.info({ pageId }, 'audit: page purged (retention)');
   }

apps/api/src/users/users.controller.ts

@@ -44,7 +44,12 @@ export class UsersController {
   @Patch()
   async updateProfile(
     @Body(new ZodValidationPipe(updateProfileInputSchema))
-    input: { displayName?: string; locale?: 'de' | 'en' },
+    input: {
+      displayName?: string;
+      locale?: 'de' | 'en';
+      autoWatchOwnPages?: boolean;
+      autoWatchOnComment?: boolean;
+    },
     @Req() request: AuthedRequest,
   ): Promise<CurrentUserShape> {
     const updated = await this.users.updateProfile(request.user!.id, input);

apps/api/src/users/users.service.ts

@@ -94,7 +94,12 @@ export class UsersService {
 
   async updateProfile(
     userId: string,
-    data: { displayName?: string; locale?: string },
+    data: {
+      displayName?: string;
+      locale?: string;
+      autoWatchOwnPages?: boolean;
+      autoWatchOnComment?: boolean;
+    },
   ): Promise<User> {
     return this.prisma.user.update({ where: { id: userId }, data });
   }

apps/api/src/watches/watches.controller.ts

@@ -0,0 +1,59 @@
+import { Controller, Delete, Get, Param, Put, Req } from '@nestjs/common';
+import {
+  WATCH_TARGET_TYPES,
+  type WatchListView,
+  type WatchStateView,
+  type WatchTargetType,
+} from '@dorfteich/shared';
+import { NotFoundException } from '@nestjs/common';
+
+import { AuthedRequest } from '../auth/auth.guard';
+import { AuthenticatedOnly } from '../permissions/permission.decorators';
+import { WatchesService } from './watches.service';
+
+function asTargetType(value: string): WatchTargetType {
+  if (!(WATCH_TARGET_TYPES as readonly string[]).includes(value)) throw new NotFoundException();
+  return value as WatchTargetType;
+}
+
+/** Watch/unwatch pages and ponds + the account's watch list (issue #93). */
+@Controller()
+export class WatchesController {
+  constructor(private readonly watches: WatchesService) {}
+
+  @Get('users/me/watches')
+  @AuthenticatedOnly()
+  async list(@Req() request: AuthedRequest): Promise<WatchListView> {
+    return this.watches.listOwn(request.user!);
+  }
+
+  @Get('watches/:targetType/:id')
+  @AuthenticatedOnly()
+  async state(
+    @Param('targetType') targetType: string,
+    @Param('id') id: string,
+    @Req() request: AuthedRequest,
+  ): Promise<WatchStateView> {
+    return this.watches.state(request.user!, asTargetType(targetType), id);
+  }
+
+  @Put('watches/:targetType/:id')
+  @AuthenticatedOnly()
+  async watch(
+    @Param('targetType') targetType: string,
+    @Param('id') id: string,
+    @Req() request: AuthedRequest,
+  ): Promise<WatchStateView> {
+    return this.watches.watch(request.user!, asTargetType(targetType), id);
+  }
+
+  @Delete('watches/:targetType/:id')
+  @AuthenticatedOnly()
+  async unwatch(
+    @Param('targetType') targetType: string,
+    @Param('id') id: string,
+    @Req() request: AuthedRequest,
+  ): Promise<WatchStateView> {
+    return this.watches.unwatch(request.user!, asTargetType(targetType), id);
+  }
+}

apps/api/src/watches/watches.e2e.db.test.ts

@@ -0,0 +1,226 @@
+import { INestApplication } from '@nestjs/common';
+import type { WatchListView, WatchStateView } from '@dorfteich/shared';
+import { PrismaClient, User } from '@prisma/client';
+import request from 'supertest';
+import { afterAll, beforeAll, describe, expect, it } from 'vitest';
+
+import { createTestApp, sessionCookieOf } from '../testing/test-app';
+import { createTestPrisma, hasTestDb, uniqueSuffix } from '../testing/test-db';
+import { UsersService } from '../users/users.service';
+
+/**
+ * Watches end to end (issue #93): per-user round-trip, read-gated targets,
+ * preference-gated auto-watch for own pages and comments, the settings
+ * list with unwatch for both target types, and purge cleanup.
+ */
+describe.skipIf(!hasTestDb)('watches (e2e, issue #93)', () => {
+  let app: INestApplication;
+  let prisma: PrismaClient;
+  const suffix = uniqueSuffix();
+  const password = 'beobachten heisst kuemmern 1';
+  const users: Record<string, User> = {};
+  const cookies: Record<string, string> = {};
+  let pondId: string;
+
+  const api = () => request(app.getHttpServer());
+
+  async function makeUser(handle: string): Promise<void> {
+    const service = app.get(UsersService);
+    const username = `wa-${handle}-${suffix}`;
+    const user = await service.createUser({
+      username,
+      email: `${username}@example.org`,
+      displayName: `Wa ${handle}`,
+      password,
+      locale: 'en',
+    });
+    await service.markEmailVerified(user.id);
+    users[handle] = user;
+    cookies[handle] = sessionCookieOf(
+      await api()
+        .post('/api/v1/auth/login')
+        .send({ usernameOrEmail: username, password })
+        .expect(200),
+    );
+  }
+
+  async function createPage(cookie: string, title: string): Promise<string> {
+    const res = await api()
+      .post(`/api/v1/ponds/${pondId}/pages`)
+      .set('Cookie', cookie)
+      .send({ title })
+      .expect(201);
+    return (res.body as { id: string }).id;
+  }
+
+  beforeAll(async () => {
+    prisma = createTestPrisma();
+    await prisma.rateLimit.deleteMany({});
+    app = await createTestApp();
+    for (const handle of ['owner', 'member', 'outsider']) await makeUser(handle);
+
+    const pond = await prisma.pond.create({
+      data: {
+        slug: `wa-pond-${suffix}`,
+        name: 'Watch Pond',
+        type: 'SHARED',
+        ownerId: users.owner!.id,
+      },
+    });
+    pondId = pond.id;
+    for (const [handle, role] of [
+      ['owner', 'POND_ADMIN'],
+      ['member', 'EDITOR'],
+    ] as const) {
+      await prisma.roleGrant.create({
+        data: {
+          pondId,
+          subjectType: 'USER',
+          subjectId: users[handle]!.id,
+          role,
+          scopeType: 'POND',
+          effect: 'ALLOW',
+          createdBy: users.owner!.id,
+        },
+      });
+    }
+  });
+
+  afterAll(async () => {
+    const ids = Object.values(users).map((u) => u.id);
+    await prisma.watch.deleteMany({ where: { userId: { in: ids } } });
+    await prisma.comment.deleteMany({ where: { page: { pondId } } });
+    await prisma.roleGrant.deleteMany({ where: { pondId } });
+    await prisma.page.deleteMany({ where: { pondId } });
+    await prisma.pond.deleteMany({ where: { id: pondId } });
+    await prisma.auditEntry.deleteMany({ where: { actorId: { in: ids } } });
+    await prisma.session.deleteMany({ where: { userId: { in: ids } } });
+    await prisma.userIdentity.deleteMany({ where: { userId: { in: ids } } });
+    await prisma.user.deleteMany({ where: { id: { in: ids } } });
+    await prisma.$disconnect();
+    await app.close();
+  });
+
+  it('round-trips watch state per user for pages and ponds', async () => {
+    const pageId = await createPage(cookies.owner!, 'Watched page');
+    // Page creation auto-watched it for the owner; drop that to test manually.
+    await api().delete(`/api/v1/watches/page/${pageId}`).set('Cookie', cookies.owner!).expect(200);
+
+    await api().put(`/api/v1/watches/page/${pageId}`).set('Cookie', cookies.member!).expect(200);
+    await api().put(`/api/v1/watches/pond/${pondId}`).set('Cookie', cookies.member!).expect(200);
+
+    const memberState = (
+      await api().get(`/api/v1/watches/page/${pageId}`).set('Cookie', cookies.member!).expect(200)
+    ).body as WatchStateView;
+    expect(memberState.watched).toBe(true);
+    // Per-user: the owner is not subscribed just because the member is.
+    const ownerState = (
+      await api().get(`/api/v1/watches/page/${pageId}`).set('Cookie', cookies.owner!).expect(200)
+    ).body as WatchStateView;
+    expect(ownerState.watched).toBe(false);
+
+    // Watching needs read access: the outsider gets a 404, never a row.
+    await api().put(`/api/v1/watches/page/${pageId}`).set('Cookie', cookies.outsider!).expect(404);
+    await api().put(`/api/v1/watches/pond/${pondId}`).set('Cookie', cookies.outsider!).expect(404);
+  });
+
+  it('auto-watches own pages and commented pages, gated by the preferences', async () => {
+    // Default preferences: creating a page subscribes its author …
+    const created = await createPage(cookies.member!, 'Auto watched');
+    expect(
+      (
+        (await api()
+          .get(`/api/v1/watches/page/${created}`)
+          .set('Cookie', cookies.member!)
+          .expect(200)) as { body: WatchStateView }
+      ).body.watched,
+    ).toBe(true);
+
+    // … and commenting subscribes the commenter.
+    await api()
+      .post(`/api/v1/pages/${created}/comments`)
+      .set('Cookie', cookies.owner!)
+      .send({ body: 'watching this now' })
+      .expect(201);
+    expect(
+      (
+        (await api()
+          .get(`/api/v1/watches/page/${created}`)
+          .set('Cookie', cookies.owner!)
+          .expect(200)) as { body: WatchStateView }
+      ).body.watched,
+    ).toBe(true);
+
+    // Disabling the preferences stops both behaviors.
+    await api()
+      .patch('/api/v1/users/me')
+      .set('Cookie', cookies.member!)
+      .send({ autoWatchOwnPages: false, autoWatchOnComment: false })
+      .expect(200);
+    const second = await createPage(cookies.member!, 'Not auto watched');
+    expect(
+      (
+        (await api()
+          .get(`/api/v1/watches/page/${second}`)
+          .set('Cookie', cookies.member!)
+          .expect(200)) as { body: WatchStateView }
+      ).body.watched,
+    ).toBe(false);
+    await api()
+      .post(`/api/v1/pages/${second}/comments`)
+      .set('Cookie', cookies.member!)
+      .send({ body: 'no subscription please' })
+      .expect(201);
+    expect(
+      (
+        (await api()
+          .get(`/api/v1/watches/page/${second}`)
+          .set('Cookie', cookies.member!)
+          .expect(200)) as { body: WatchStateView }
+      ).body.watched,
+    ).toBe(false);
+  });
+
+  it('lists own watches with names and unwatches both types from settings', async () => {
+    const pageId = await createPage(cookies.owner!, 'Listed page');
+    await api().put(`/api/v1/watches/page/${pageId}`).set('Cookie', cookies.member!).expect(200);
+    await api().put(`/api/v1/watches/pond/${pondId}`).set('Cookie', cookies.member!).expect(200);
+
+    const list = (
+      await api().get('/api/v1/users/me/watches').set('Cookie', cookies.member!).expect(200)
+    ).body as WatchListView;
+    const pageEntry = list.watches.find((w) => w.targetId === pageId);
+    const pondEntry = list.watches.find((w) => w.targetId === pondId);
+    expect(pageEntry).toMatchObject({ targetType: 'page', name: 'Listed page' });
+    expect(pageEntry?.slug).toBeTruthy();
+    expect(pondEntry).toMatchObject({ targetType: 'pond', name: 'Watch Pond', slug: null });
+
+    // Unwatch both types (the settings list's action).
+    await api().delete(`/api/v1/watches/page/${pageId}`).set('Cookie', cookies.member!).expect(200);
+    await api().delete(`/api/v1/watches/pond/${pondId}`).set('Cookie', cookies.member!).expect(200);
+    const after = (
+      await api().get('/api/v1/users/me/watches').set('Cookie', cookies.member!).expect(200)
+    ).body as WatchListView;
+    expect(after.watches.find((w) => w.targetId === pageId)).toBeUndefined();
+    expect(after.watches.find((w) => w.targetId === pondId)).toBeUndefined();
+  });
+
+  it('drops unreadable targets from the list and cleans up on purge', async () => {
+    const pageId = await createPage(cookies.owner!, 'Vanishing page');
+    await api().put(`/api/v1/watches/page/${pageId}`).set('Cookie', cookies.member!).expect(200);
+
+    // Trash hides it from the list (target no longer live) …
+    await prisma.page.update({
+      where: { id: pageId },
+      data: { deletedAt: new Date(), deletedBy: users.owner!.id },
+    });
+    const list = (
+      await api().get('/api/v1/users/me/watches').set('Cookie', cookies.member!).expect(200)
+    ).body as WatchListView;
+    expect(list.watches.find((w) => w.targetId === pageId)).toBeUndefined();
+
+    // … and purge removes the rows entirely (trash service hook).
+    await api().delete(`/api/v1/pages/${pageId}/purge`).set('Cookie', cookies.owner!).expect(204);
+    expect(await prisma.watch.count({ where: { targetId: pageId } })).toBe(0);
+  });
+});

apps/api/src/watches/watches.module.ts

@@ -0,0 +1,14 @@
+import { Module } from '@nestjs/common';
+
+import { PermissionsModule } from '../permissions/permissions.module';
+
+import { WatchesController } from './watches.controller';
+import { WatchesService } from './watches.service';
+
+@Module({
+  imports: [PermissionsModule],
+  controllers: [WatchesController],
+  providers: [WatchesService],
+  exports: [WatchesService],
+})
+export class WatchesModule {}

apps/api/src/watches/watches.service.ts

@@ -0,0 +1,149 @@
+import { Injectable, NotFoundException } from '@nestjs/common';
+import type { WatchListView, WatchStateView, WatchTargetType, WatchView } from '@dorfteich/shared';
+import { User, WatchTargetType as DbTargetType } from '@prisma/client';
+
+import { PermissionService } from '../permissions/permission.service';
+import { PrismaService } from '../prisma/prisma.service';
+
+const dbType = (targetType: WatchTargetType): DbTargetType =>
+  targetType === 'page' ? 'PAGE' : 'POND';
+
+/**
+ * Explicit page/pond subscriptions (issue #93) — the input side of the
+ * notification model (#94). Watching needs read access to the target (404
+ * hides what the user cannot see, issue #60); both watch and unwatch are
+ * idempotent. The list resolves current names and silently drops targets
+ * that vanished or became unreadable — stale rows are harmless.
+ */
+@Injectable()
+export class WatchesService {
+  constructor(
+    private readonly prisma: PrismaService,
+    private readonly permissions: PermissionService,
+  ) {}
+
+  /** Read access to the (live) target, or 404. */
+  private async assertReadable(
+    user: User,
+    targetType: WatchTargetType,
+    targetId: string,
+  ): Promise<void> {
+    if (targetType === 'page') {
+      const page = await this.prisma.page.findFirst({
+        where: { id: targetId, deletedAt: null },
+        select: { id: true, pondId: true },
+      });
+      if (!page || !(await this.permissions.canAccessPage(user, page, 'read'))) {
+        throw new NotFoundException();
+      }
+      return;
+    }
+    const pond = await this.prisma.pond.findFirst({ where: { id: targetId, deletedAt: null } });
+    if (!pond || !(await this.permissions.canSeePond(user, targetId))) {
+      throw new NotFoundException();
+    }
+  }
+
+  async watch(user: User, targetType: WatchTargetType, targetId: string): Promise<WatchStateView> {
+    await this.assertReadable(user, targetType, targetId);
+    await this.upsert(user.id, targetType, targetId);
+    return { watched: true };
+  }
+
+  async unwatch(
+    user: User,
+    targetType: WatchTargetType,
+    targetId: string,
+  ): Promise<WatchStateView> {
+    await this.prisma.watch.deleteMany({
+      where: { userId: user.id, targetType: dbType(targetType), targetId },
+    });
+    return { watched: false };
+  }
+
+  async state(user: User, targetType: WatchTargetType, targetId: string): Promise<WatchStateView> {
+    const existing = await this.prisma.watch.findFirst({
+      where: { userId: user.id, targetType: dbType(targetType), targetId },
+    });
+    return { watched: existing !== null };
+  }
+
+  /**
+   * Auto-watch hook (issue #93): creating a page or commenting subscribes
+   * the actor — each behind its user preference. Fire-and-forget semantics:
+   * a failure here must never break the page/comment write.
+   */
+  async autoWatchPage(user: User, pageId: string, kind: 'ownPage' | 'comment'): Promise<void> {
+    const enabled = kind === 'ownPage' ? user.autoWatchOwnPages : user.autoWatchOnComment;
+    if (!enabled) return;
+    await this.upsert(user.id, 'page', pageId);
+  }
+
+  private async upsert(
+    userId: string,
+    targetType: WatchTargetType,
+    targetId: string,
+  ): Promise<void> {
+    await this.prisma.watch.upsert({
+      where: {
+        userId_targetType_targetId: { userId, targetType: dbType(targetType), targetId },
+      },
+      create: { userId, targetType: dbType(targetType), targetId },
+      update: {},
+    });
+  }
+
+  /** The account-settings list: resolved names, unreadable targets dropped. */
+  async listOwn(user: User): Promise<WatchListView> {
+    const rows = await this.prisma.watch.findMany({
+      where: { userId: user.id },
+      orderBy: { createdAt: 'desc' },
+    });
+
+    const watches: WatchView[] = [];
+    for (const row of rows) {
+      if (row.targetType === 'PAGE') {
+        const page = await this.prisma.page.findFirst({
+          where: { id: row.targetId, deletedAt: null },
+          select: { id: true, pondId: true, title: true, slug: true },
+        });
+        if (!page || !(await this.permissions.canAccessPage(user, page, 'read'))) continue;
+        const pond = await this.prisma.pond.findFirst({
+          where: { id: page.pondId, deletedAt: null },
+          select: { slug: true },
+        });
+        if (!pond) continue;
+        watches.push({
+          id: row.id,
+          targetType: 'page',
+          targetId: row.targetId,
+          name: page.title,
+          pondSlug: pond.slug,
+          slug: page.slug,
+          createdAt: row.createdAt.toISOString(),
+        });
+      } else {
+        const pond = await this.prisma.pond.findFirst({
+          where: { id: row.targetId, deletedAt: null },
+          select: { name: true, slug: true },
+        });
+        if (!pond || !(await this.permissions.canSeePond(user, row.targetId))) continue;
+        watches.push({
+          id: row.id,
+          targetType: 'pond',
+          targetId: row.targetId,
+          name: pond.name,
+          pondSlug: pond.slug,
+          slug: null,
+          createdAt: row.createdAt.toISOString(),
+        });
+      }
+    }
+    return { watches };
+  }
+
+  /** Page purge (trash retention or manual) removes its watches. */
+  async removeForPage(pageId: string): Promise<void> {
+    await this.prisma.watch.deleteMany({ where: { targetType: 'PAGE', targetId: pageId } });
+  }
+}

apps/web/src/i18n/index.ts

@@ -19,6 +19,7 @@ import deSearch from '@dorfteich/shared/i18n/de/search.json';
 import deSetup from '@dorfteich/shared/i18n/de/setup.json';
 import deSystem from '@dorfteich/shared/i18n/de/system.json';
 import deUsers from '@dorfteich/shared/i18n/de/users.json';
+import deWatches from '@dorfteich/shared/i18n/de/watches.json';
 import deSettings from '@dorfteich/shared/i18n/de/settings.json';
 import enAccess from '@dorfteich/shared/i18n/en/access.json';
 import enAuth from '@dorfteich/shared/i18n/en/auth.json';
@@ -41,6 +42,7 @@ import enSearch from '@dorfteich/shared/i18n/en/search.json';
 import enSetup from '@dorfteich/shared/i18n/en/setup.json';
 import enSystem from '@dorfteich/shared/i18n/en/system.json';
 import enUsers from '@dorfteich/shared/i18n/en/users.json';
+import enWatches from '@dorfteich/shared/i18n/en/watches.json';
 import enSettings from '@dorfteich/shared/i18n/en/settings.json';
 import i18n from 'i18next';
 import LanguageDetector from 'i18next-browser-languagedetector';
@@ -80,6 +82,7 @@ void i18n
         setup: enSetup,
         system: enSystem,
         users: enUsers,
+        watches: enWatches,
       },
       de: {
         common: deCommon,
@@ -104,6 +107,7 @@ void i18n
         setup: deSetup,
         system: deSystem,
         users: deUsers,
+        watches: deWatches,
       },
     },
     defaultNS: 'common',

apps/web/src/pages/PageEditorPage.tsx

@@ -28,6 +28,7 @@ import { useCollabProvider } from '../editor/use-collab-provider';
 import { WikilinkAutocomplete } from '../editor/WikilinkAutocomplete';
 import { WikilinkContext, makeWikilinkResolver } from '../editor/wikilink-context';
 import { useForceSidebarHidden } from '../layout/sidebar-chrome';
+import { WatchToggle } from '../watches/WatchToggle';
 import { ApiError, apiDelete, apiGet, apiGetText, apiPatch } from '../lib/api';
 import { recallPage, rememberPage } from '../offline/page-cache';
 import { PluginBlockContext } from '../editor/plugin-block-context';
@@ -429,6 +430,7 @@ export function PageEditorPage(): React.JSX.Element {
             onChange={(event) => setTitle(event.target.value)}
             onBlur={() => void saveTitle()}
           />
+          <WatchToggle targetType="page" targetId={resolved.id} />
           <button
             type="button"
             className="button editor-page__mode-toggle"

apps/web/src/pages/PondSettingsPage.tsx

@@ -5,6 +5,7 @@ import { useParams } from 'react-router-dom';
 
 import { useAuth } from '../auth/auth-context';
 import { CommentPolicySetting } from '../comments/CommentPolicySetting';
+import { WatchToggle } from '../watches/WatchToggle';
 import { FormError } from '../components/forms';
 import { AppearanceManager } from '../fonts/AppearanceManager';
 import { LabelManager } from '../labels/LabelManager';
@@ -48,7 +49,10 @@ export function PondSettingsPage(): React.JSX.Element {
 
   return (
     <div className="pond-settings-page">
-      <h1>{pond.data.name}</h1>
+      <div className="pond-settings-page__header">
+        <h1>{pond.data.name}</h1>
+        <WatchToggle targetType="pond" targetId={pond.data.id} />
+      </div>
       <section>
         <h2>{tMembers('title')}</h2>
         <MemberManager pondId={pond.data.id} />

apps/web/src/pages/SettingsPage.tsx

@@ -9,6 +9,7 @@ import { useAuth } from '../auth/auth-context';
 import { Field, FormError, FormSuccess, applyFieldErrors } from '../components/forms';
 import { useDataExport } from '../export/use-data-export';
 import { apiDelete, apiGet, apiPatch, apiPost } from '../lib/api';
+import { WatchesSection } from '../watches/WatchesSection';
 
 interface SessionView {
   id: string;
@@ -26,6 +27,7 @@ export function SettingsPage(): React.JSX.Element {
       <ProfileSection />
       <PasswordSection />
       <SessionsSection />
+      <WatchesSection />
       <DataExportSection />
     </>
   );
@@ -83,9 +85,19 @@ function ProfileSection(): React.JSX.Element {
   const [error, setError] = useState<unknown>(null);
   const [saved, setSaved] = useState(false);
 
-  const form = useForm<{ displayName?: string; locale?: 'de' | 'en' }>({
+  const form = useForm<{
+    displayName?: string;
+    locale?: 'de' | 'en';
+    autoWatchOwnPages?: boolean;
+    autoWatchOnComment?: boolean;
+  }>({
     resolver: zodResolver(updateProfileInputSchema),
-    values: { displayName: user?.displayName, locale: user?.locale },
+    values: {
+      displayName: user?.displayName,
+      locale: user?.locale,
+      autoWatchOwnPages: user?.autoWatchOwnPages,
+      autoWatchOnComment: user?.autoWatchOnComment,
+    },
   });
 
   const onSubmit = form.handleSubmit(async (input) => {
@@ -123,6 +135,14 @@ function ProfileSection(): React.JSX.Element {
             <option value="en">{t('settings:profile.locales.en')}</option>
           </select>
         </Field>
+        <label className="settings-checkbox">
+          <input type="checkbox" {...form.register('autoWatchOwnPages')} />
+          {t('watches:prefs.autoWatchOwnPages')}
+        </label>
+        <label className="settings-checkbox">
+          <input type="checkbox" {...form.register('autoWatchOnComment')} />
+          {t('watches:prefs.autoWatchOnComment')}
+        </label>
         <button type="submit" className="button" disabled={form.formState.isSubmitting}>
           {t('settings:profile.save')}
         </button>

apps/web/src/styles/base.css

@@ -2495,3 +2495,42 @@ button {
   color: var(--color-text-muted);
   font-size: 0.8125rem;
 }
+
+/* Watches (issue #93) */
+.watch-toggle--active {
+  background: var(--color-primary, #2f6f4f);
+  color: #fff;
+}
+
+.watches-list {
+  list-style: none;
+  margin: 0;
+  padding: 0;
+  display: flex;
+  flex-direction: column;
+  gap: var(--space-2);
+}
+
+.watches-list li {
+  display: flex;
+  align-items: center;
+  gap: var(--space-3);
+}
+
+.watches-list__type {
+  color: var(--color-text-muted);
+  font-size: 0.8125rem;
+}
+
+.settings-checkbox {
+  display: flex;
+  align-items: center;
+  gap: var(--space-2);
+  margin: var(--space-2) 0;
+}
+
+.pond-settings-page__header {
+  display: flex;
+  align-items: center;
+  gap: var(--space-3);
+}

apps/web/src/watches/WatchToggle.tsx

@@ -0,0 +1,47 @@
+import type { WatchStateView, WatchTargetType } from '@dorfteich/shared';
+import { useQuery, useQueryClient } from '@tanstack/react-query';
+import { useTranslation } from 'react-i18next';
+
+import { apiDelete, apiGet, apiPut } from '../lib/api';
+
+/**
+ * Watch/unwatch button for page and pond headers (issue #93). The state is
+ * per-user (server-side); toggling updates optimistically via refetch.
+ */
+export function WatchToggle({
+  targetType,
+  targetId,
+}: {
+  targetType: WatchTargetType;
+  targetId: string;
+}): React.JSX.Element {
+  const { t } = useTranslation('watches');
+  const queryClient = useQueryClient();
+  const key = ['watch', targetType, targetId];
+
+  const state = useQuery({
+    queryKey: key,
+    queryFn: () => apiGet<WatchStateView>(`/watches/${targetType}/${targetId}`),
+  });
+
+  const toggle = async (): Promise<void> => {
+    const watched = state.data?.watched ?? false;
+    if (watched) await apiDelete(`/watches/${targetType}/${targetId}`);
+    else await apiPut(`/watches/${targetType}/${targetId}`, {});
+    await queryClient.invalidateQueries({ queryKey: key });
+    await queryClient.invalidateQueries({ queryKey: ['watches'] });
+  };
+
+  const watched = state.data?.watched ?? false;
+  return (
+    <button
+      type="button"
+      className={`button watch-toggle${watched ? ' watch-toggle--active' : ''}`}
+      aria-pressed={watched}
+      disabled={state.isLoading}
+      onClick={() => void toggle()}
+    >
+      {watched ? t('watching') : t('watch')}
+    </button>
+  );
+}

apps/web/src/watches/WatchesSection.tsx

@@ -0,0 +1,57 @@
+import type { WatchListView } from '@dorfteich/shared';
+import { useQuery, useQueryClient } from '@tanstack/react-query';
+import { useTranslation } from 'react-i18next';
+import { Link } from 'react-router-dom';
+
+import { apiDelete, apiGet } from '../lib/api';
+
+/**
+ * The account's watch list (issue #93): everything the user follows, with
+ * links to the targets and an unwatch action per entry.
+ */
+export function WatchesSection(): React.JSX.Element {
+  const { t } = useTranslation('watches');
+  const queryClient = useQueryClient();
+  const list = useQuery({
+    queryKey: ['watches'],
+    queryFn: () => apiGet<WatchListView>('/users/me/watches'),
+  });
+
+  const unwatch = async (targetType: string, targetId: string): Promise<void> => {
+    await apiDelete(`/watches/${targetType}/${targetId}`);
+    await queryClient.invalidateQueries({ queryKey: ['watches'] });
+    await queryClient.invalidateQueries({ queryKey: ['watch', targetType, targetId] });
+  };
+
+  return (
+    <section className="settings-section">
+      <h2>{t('settings.title')}</h2>
+      {list.data && list.data.watches.length === 0 && <p>{t('settings.empty')}</p>}
+      {list.data && list.data.watches.length > 0 && (
+        <ul className="watches-list">
+          {list.data.watches.map((watch) => (
+            <li key={watch.id}>
+              <Link
+                to={
+                  watch.targetType === 'pond'
+                    ? `/p/${watch.pondSlug}`
+                    : `/p/${watch.pondSlug}/${watch.slug}`
+                }
+              >
+                {watch.name}
+              </Link>
+              <span className="watches-list__type">{t(`settings.types.${watch.targetType}`)}</span>
+              <button
+                type="button"
+                className="button"
+                onClick={() => void unwatch(watch.targetType, watch.targetId)}
+              >
+                {t('settings.unwatch')}
+              </button>
+            </li>
+          ))}
+        </ul>
+      )}
+    </section>
+  );
+}

packages/shared/i18n/de/watches.json

@@ -0,0 +1,17 @@
+{
+  "watch": "Beobachten",
+  "watching": "Beobachtet",
+  "settings": {
+    "title": "Beobachtete Seiten und Teiche",
+    "empty": "Du beobachtest noch nichts — nutze den Beobachten-Button auf einer Seite oder einem Teich.",
+    "unwatch": "Nicht mehr beobachten",
+    "types": {
+      "page": "Seite",
+      "pond": "Teich"
+    }
+  },
+  "prefs": {
+    "autoWatchOwnPages": "Seiten, die ich anlege, automatisch beobachten",
+    "autoWatchOnComment": "Seiten, die ich kommentiere, automatisch beobachten"
+  }
+}

packages/shared/i18n/en/watches.json

@@ -0,0 +1,17 @@
+{
+  "watch": "Watch",
+  "watching": "Watching",
+  "settings": {
+    "title": "Watched pages and ponds",
+    "empty": "You are not watching anything yet — use the Watch button on a page or pond.",
+    "unwatch": "Unwatch",
+    "types": {
+      "page": "Page",
+      "pond": "Pond"
+    }
+  },
+  "prefs": {
+    "autoWatchOwnPages": "Automatically watch pages I create",
+    "autoWatchOnComment": "Automatically watch pages I comment on"
+  }
+}

packages/shared/src/auth.ts

@@ -71,6 +71,9 @@ export const resetPasswordFormSchema = z.object({ password: passwordSchema });
 export const updateProfileInputSchema = z.object({
   displayName: z.string().trim().min(1, 'validation.displayName.required').max(80).optional(),
   locale: z.enum(['de', 'en']).optional(),
+  /** Auto-watch preferences (issue #93). */
+  autoWatchOwnPages: z.boolean().optional(),
+  autoWatchOnComment: z.boolean().optional(),
 });
 export const changePasswordInputSchema = z.object({
   currentPassword: z.string().min(1, 'validation.required'),
@@ -85,4 +88,6 @@ export interface CurrentUser {
   displayName: string;
   locale: 'de' | 'en';
   isSiteAdmin: boolean;
+  autoWatchOwnPages: boolean;
+  autoWatchOnComment: boolean;
 }

packages/shared/src/index.ts

@@ -25,3 +25,4 @@ export * from './system';
 export * from './ponds';
 export * from './quotas';
 export * from './text-diff';
+export * from './watches';

packages/shared/src/watches.ts

@@ -0,0 +1,29 @@
+/**
+ * Watches (issue #93, data-model.md §watches): explicit per-user
+ * subscriptions to pages or whole ponds — the input side of the
+ * notification model (#94).
+ */
+
+export const WATCH_TARGET_TYPES = ['page', 'pond'] as const;
+export type WatchTargetType = (typeof WATCH_TARGET_TYPES)[number];
+
+export interface WatchView {
+  id: string;
+  targetType: WatchTargetType;
+  targetId: string;
+  /** Page title or pond name. */
+  name: string;
+  /** Link target: `/p/<pondSlug>` for ponds, `/p/<pondSlug>/<slug>` for pages. */
+  pondSlug: string;
+  slug: string | null;
+  createdAt: string;
+}
+
+export interface WatchListView {
+  watches: WatchView[];
+}
+
+/** The toggle state the page/pond headers need. */
+export interface WatchStateView {
+  watched: boolean;
+}