adding chat features, admin features and bug fixes

2026-03-12 08:16:34 +01:00
parent 7b14e3d5ba
commit 31f1414e06
43 changed files with 2610 additions and 16 deletions
--- a/backend/src/app.ts
+++ b/backend/src/app.ts
@@ -83,6 +83,8 @@ import bookingRoutes     from './routes/booking.routes';
 import notificationRoutes from './routes/notification.routes';
 import bookstackRoutes   from './routes/bookstack.routes';
 import vikunjaRoutes     from './routes/vikunja.routes';
+import configRoutes      from './routes/config.routes';
+import serviceMonitorRoutes from './routes/serviceMonitor.routes';

 app.use('/api/auth',        authRoutes);
 app.use('/api/user',        userRoutes);
@@ -99,6 +101,8 @@ app.use('/api/bookings',    bookingRoutes);
 app.use('/api/notifications', notificationRoutes);
 app.use('/api/bookstack',   bookstackRoutes);
 app.use('/api/vikunja',    vikunjaRoutes);
+app.use('/api/config',     configRoutes);
+app.use('/api/admin',      serviceMonitorRoutes);

 // 404 handler
 app.use(notFoundHandler);
--- a/backend/src/controllers/bookstack.controller.ts
+++ b/backend/src/controllers/bookstack.controller.ts
@@ -40,6 +40,24 @@ class BookStackController {
      res.status(500).json({ success: false, message: 'BookStack-Suche fehlgeschlagen' });
    }
  }
+  async getPage(req: Request, res: Response): Promise<void> {
+    if (!environment.bookstack.url) {
+      res.status(200).json({ success: true, data: null, configured: false });
+      return;
+    }
+    const id = parseInt(String(req.params.id), 10);
+    if (isNaN(id) || id <= 0) {
+      res.status(400).json({ success: false, message: 'Ungültige Seiten-ID' });
+      return;
+    }
+    try {
+      const page = await bookstackService.getPageById(id);
+      res.status(200).json({ success: true, data: page, configured: true });
+    } catch (error) {
+      logger.error('BookStackController.getPage error', { error });
+      res.status(500).json({ success: false, message: 'BookStack-Seite konnte nicht geladen werden' });
+    }
+  }
 }

 export default new BookStackController();
--- a/backend/src/controllers/config.controller.ts
+++ b/backend/src/controllers/config.controller.ts
@@ -0,0 +1,14 @@
+import { Request, Response } from 'express';
+import environment from '../config/environment';
+
+class ConfigController {
+  async getExternalLinks(_req: Request, res: Response): Promise<void> {
+    const links: Record<string, string> = {};
+    if (environment.nextcloudUrl) links.nextcloud = environment.nextcloudUrl;
+    if (environment.bookstack.url) links.bookstack = environment.bookstack.url;
+    if (environment.vikunja.url) links.vikunja = environment.vikunja.url;
+    res.status(200).json({ success: true, data: links });
+  }
+}
+
+export default new ConfigController();
--- a/backend/src/controllers/nextcloud.controller.ts
+++ b/backend/src/controllers/nextcloud.controller.ts
@@ -80,6 +80,91 @@ class NextcloudController {
      res.status(500).json({ success: false, message: 'Nextcloud-Trennung fehlgeschlagen' });
    }
  }
+
+  async getRooms(req: Request, res: Response): Promise<void> {
+    try {
+      const credentials = await userService.getNextcloudCredentials(req.user!.id);
+      if (!credentials) {
+        res.status(200).json({ success: true, data: { connected: false, rooms: [] } });
+        return;
+      }
+      const rooms = await nextcloudService.getAllConversations(credentials.loginName, credentials.appPassword);
+      res.status(200).json({ success: true, data: { connected: true, rooms, loginName: credentials.loginName } });
+    } catch (error: any) {
+      if (error?.code === 'NEXTCLOUD_AUTH_INVALID') {
+        await userService.clearNextcloudCredentials(req.user!.id);
+        res.status(200).json({ success: true, data: { connected: false, rooms: [] } });
+        return;
+      }
+      logger.error('getRooms error', { error });
+      res.status(500).json({ success: false, message: 'Nextcloud-Räume konnten nicht geladen werden' });
+    }
+  }
+
+  async getMessages(req: Request, res: Response): Promise<void> {
+    try {
+      const credentials = await userService.getNextcloudCredentials(req.user!.id);
+      if (!credentials) {
+        res.status(401).json({ success: false, message: 'Nextcloud nicht verbunden' });
+        return;
+      }
+      const token = req.params.token as string;
+      if (!token) {
+        res.status(400).json({ success: false, message: 'Room token fehlt' });
+        return;
+      }
+      const messages = await nextcloudService.getMessages(token, credentials.loginName, credentials.appPassword);
+      res.status(200).json({ success: true, data: messages });
+    } catch (error) {
+      logger.error('getMessages error', { error });
+      res.status(500).json({ success: false, message: 'Nachrichten konnten nicht geladen werden' });
+    }
+  }
+
+  async sendMessage(req: Request, res: Response): Promise<void> {
+    try {
+      const credentials = await userService.getNextcloudCredentials(req.user!.id);
+      if (!credentials) {
+        res.status(401).json({ success: false, message: 'Nextcloud nicht verbunden' });
+        return;
+      }
+      const token = req.params.token as string;
+      const { message } = req.body;
+      if (!token || !message || typeof message !== 'string' || message.trim().length === 0) {
+        res.status(400).json({ success: false, message: 'Token und Nachricht erforderlich' });
+        return;
+      }
+      if (message.length > 32000) {
+        res.status(400).json({ success: false, message: 'Nachricht zu lang' });
+        return;
+      }
+      await nextcloudService.sendMessage(token, message.trim(), credentials.loginName, credentials.appPassword);
+      res.status(200).json({ success: true, data: null });
+    } catch (error) {
+      logger.error('sendMessage error', { error });
+      res.status(500).json({ success: false, message: 'Nachricht konnte nicht gesendet werden' });
+    }
+  }
+
+  async markRoomAsRead(req: Request, res: Response): Promise<void> {
+    try {
+      const credentials = await userService.getNextcloudCredentials(req.user!.id);
+      if (!credentials) {
+        res.status(401).json({ success: false, message: 'Nextcloud nicht verbunden' });
+        return;
+      }
+      const token = req.params.token as string;
+      if (!token) {
+        res.status(400).json({ success: false, message: 'Room token fehlt' });
+        return;
+      }
+      await nextcloudService.markAsRead(token, credentials.loginName, credentials.appPassword);
+      res.status(200).json({ success: true, data: null });
+    } catch (error) {
+      logger.error('markRoomAsRead error', { error });
+      res.status(500).json({ success: false, message: 'Raum konnte nicht als gelesen markiert werden' });
+    }
+  }
 }

 export default new NextcloudController();
--- a/backend/src/controllers/serviceMonitor.controller.ts
+++ b/backend/src/controllers/serviceMonitor.controller.ts
@@ -0,0 +1,192 @@
+import { Request, Response } from 'express';
+import { z } from 'zod';
+import serviceMonitorService from '../services/serviceMonitor.service';
+import notificationService from '../services/notification.service';
+import pool from '../config/database';
+import logger from '../utils/logger';
+
+const createServiceSchema = z.object({
+  name: z.string().min(1).max(200),
+  url: z.string().url().max(500),
+});
+
+const updateServiceSchema = z.object({
+  name: z.string().min(1).max(200).optional(),
+  url: z.string().url().max(500).optional(),
+  is_active: z.boolean().optional(),
+});
+
+const broadcastSchema = z.object({
+  titel: z.string().min(1).max(200),
+  nachricht: z.string().min(1).max(2000),
+  schwere: z.enum(['info', 'warnung', 'fehler']).default('info'),
+  targetGroup: z.string().optional(),
+});
+
+class ServiceMonitorController {
+  async getAll(_req: Request, res: Response): Promise<void> {
+    try {
+      const services = await serviceMonitorService.getAllServices();
+      res.json({ success: true, data: services });
+    } catch (error) {
+      logger.error('Failed to get services', { error });
+      res.status(500).json({ success: false, message: 'Failed to get services' });
+    }
+  }
+
+  async create(req: Request, res: Response): Promise<void> {
+    try {
+      const { name, url } = createServiceSchema.parse(req.body);
+      const service = await serviceMonitorService.createService(name, url);
+      res.status(201).json({ success: true, data: service });
+    } catch (error) {
+      if (error instanceof z.ZodError) {
+        res.status(400).json({ success: false, message: 'Invalid input', errors: error.issues });
+        return;
+      }
+      logger.error('Failed to create service', { error });
+      res.status(500).json({ success: false, message: 'Failed to create service' });
+    }
+  }
+
+  async update(req: Request, res: Response): Promise<void> {
+    try {
+      const data = updateServiceSchema.parse(req.body);
+      const service = await serviceMonitorService.updateService(req.params.id as string, data);
+      res.json({ success: true, data: service });
+    } catch (error) {
+      if (error instanceof z.ZodError) {
+        res.status(400).json({ success: false, message: 'Invalid input', errors: error.issues });
+        return;
+      }
+      logger.error('Failed to update service', { error });
+      res.status(500).json({ success: false, message: 'Failed to update service' });
+    }
+  }
+
+  async delete(req: Request, res: Response): Promise<void> {
+    try {
+      const deleted = await serviceMonitorService.deleteService(req.params.id as string);
+      if (!deleted) {
+        res.status(404).json({ success: false, message: 'Service not found or is internal' });
+        return;
+      }
+      res.json({ success: true });
+    } catch (error) {
+      logger.error('Failed to delete service', { error });
+      res.status(500).json({ success: false, message: 'Failed to delete service' });
+    }
+  }
+
+  async pingAll(_req: Request, res: Response): Promise<void> {
+    try {
+      const results = await serviceMonitorService.pingAll();
+      res.json({ success: true, data: results });
+    } catch (error) {
+      logger.error('Failed to ping services', { error });
+      res.status(500).json({ success: false, message: 'Failed to ping services' });
+    }
+  }
+
+  async getStatusSummary(_req: Request, res: Response): Promise<void> {
+    try {
+      const summary = await serviceMonitorService.getStatusSummary();
+      res.json({ success: true, data: summary });
+    } catch (error) {
+      logger.error('Failed to get status summary', { error });
+      res.status(500).json({ success: false, message: 'Failed to get status summary' });
+    }
+  }
+
+  async getSystemHealth(_req: Request, res: Response): Promise<void> {
+    try {
+      let dbStatus = false;
+      let dbSize = '0';
+
+      try {
+        await pool.query('SELECT 1');
+        dbStatus = true;
+        const sizeResult = await pool.query('SELECT pg_database_size(current_database()) as size');
+        dbSize = sizeResult.rows[0].size;
+      } catch {
+        // DB is down
+      }
+
+      const mem = process.memoryUsage();
+      res.json({
+        success: true,
+        data: {
+          nodeVersion: process.version,
+          uptime: process.uptime(),
+          memoryUsage: {
+            heapUsed: mem.heapUsed,
+            heapTotal: mem.heapTotal,
+            rss: mem.rss,
+            external: mem.external,
+          },
+          dbStatus,
+          dbSize,
+        },
+      });
+    } catch (error) {
+      logger.error('Failed to get system health', { error });
+      res.status(500).json({ success: false, message: 'Failed to get system health' });
+    }
+  }
+
+  async getUsers(_req: Request, res: Response): Promise<void> {
+    try {
+      const result = await pool.query(
+        `SELECT id, email, name, role, authentik_groups as groups, is_active, last_login_at
+         FROM users ORDER BY name`
+      );
+      res.json({ success: true, data: result.rows });
+    } catch (error) {
+      logger.error('Failed to get users', { error });
+      res.status(500).json({ success: false, message: 'Failed to get users' });
+    }
+  }
+
+  async broadcastNotification(req: Request, res: Response): Promise<void> {
+    try {
+      const { titel, nachricht, schwere, targetGroup } = broadcastSchema.parse(req.body);
+
+      let users;
+      if (targetGroup) {
+        const result = await pool.query(
+          `SELECT id FROM users WHERE is_active = TRUE AND $1 = ANY(authentik_groups)`,
+          [targetGroup]
+        );
+        users = result.rows;
+      } else {
+        const result = await pool.query(
+          `SELECT id FROM users WHERE is_active = TRUE`
+        );
+        users = result.rows;
+      }
+
+      let sent = 0;
+      for (const user of users) {
+        await notificationService.createNotification({
+          user_id: user.id,
+          typ: 'broadcast',
+          titel,
+          nachricht,
+          schwere,
+        });
+        sent++;
+      }
+
+      res.json({ success: true, data: { sent } });
+    } catch (error) {
+      if (error instanceof z.ZodError) {
+        res.status(400).json({ success: false, message: 'Invalid input', errors: error.issues });
+        return;
+      }
+      logger.error('Failed to broadcast notification', { error });
+      res.status(500).json({ success: false, message: 'Failed to broadcast notification' });
+    }
+  }
+}
+
+export default new ServiceMonitorController();
--- a/backend/src/database/migrations/023_create_monitored_services.sql
+++ b/backend/src/database/migrations/023_create_monitored_services.sql
@@ -0,0 +1,13 @@
+CREATE TABLE IF NOT EXISTS monitored_services (
+    id         UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
+    name       VARCHAR(200) NOT NULL,
+    url        VARCHAR(500) NOT NULL,
+    type       VARCHAR(20) NOT NULL DEFAULT 'custom' CHECK (type IN ('internal','custom')),
+    is_active  BOOLEAN NOT NULL DEFAULT TRUE,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+CREATE OR REPLACE TRIGGER update_monitored_services_updated_at
+    BEFORE UPDATE ON monitored_services
+    FOR EACH ROW EXECUTE FUNCTION update_updated_at_column();
--- a/backend/src/routes/bookstack.routes.ts
+++ b/backend/src/routes/bookstack.routes.ts
@@ -6,5 +6,6 @@ const router = Router();

 router.get('/recent', authenticate, bookstackController.getRecent.bind(bookstackController));
 router.get('/search', authenticate, bookstackController.search.bind(bookstackController));
+router.get('/pages/:id', authenticate, bookstackController.getPage.bind(bookstackController));

 export default router;
--- a/backend/src/routes/config.routes.ts
+++ b/backend/src/routes/config.routes.ts
@@ -0,0 +1,8 @@
+import { Router } from 'express';
+import configController from '../controllers/config.controller';
+import { authenticate } from '../middleware/auth.middleware';
+
+const router = Router();
+router.get('/external-links', authenticate, configController.getExternalLinks.bind(configController));
+
+export default router;
--- a/backend/src/routes/nextcloud.routes.ts
+++ b/backend/src/routes/nextcloud.routes.ts
@@ -9,4 +9,9 @@ router.post('/connect', authenticate, nextcloudController.initiateConnect.bind(n
 router.post('/poll', authenticate, nextcloudController.pollConnect.bind(nextcloudController));
 router.delete('/connect', authenticate, nextcloudController.disconnect.bind(nextcloudController));

+router.get('/rooms', authenticate, nextcloudController.getRooms.bind(nextcloudController));
+router.get('/rooms/:token/messages', authenticate, nextcloudController.getMessages.bind(nextcloudController));
+router.post('/rooms/:token/messages', authenticate, nextcloudController.sendMessage.bind(nextcloudController));
+router.post('/rooms/:token/read', authenticate, nextcloudController.markRoomAsRead.bind(nextcloudController));
+
 export default router;
--- a/backend/src/routes/serviceMonitor.routes.ts
+++ b/backend/src/routes/serviceMonitor.routes.ts
@@ -0,0 +1,20 @@
+import { Router } from 'express';
+import serviceMonitorController from '../controllers/serviceMonitor.controller';
+import { authenticate } from '../middleware/auth.middleware';
+import { requirePermission } from '../middleware/rbac.middleware';
+
+const router = Router();
+const auth = [authenticate, requirePermission('admin:access')] as const;
+
+// Static routes first (before parameterized :id routes)
+router.get('/services/ping', ...auth, serviceMonitorController.pingAll.bind(serviceMonitorController));
+router.get('/services/status-summary', ...auth, serviceMonitorController.getStatusSummary.bind(serviceMonitorController));
+router.get('/services', ...auth, serviceMonitorController.getAll.bind(serviceMonitorController));
+router.post('/services', ...auth, serviceMonitorController.create.bind(serviceMonitorController));
+router.put('/services/:id', ...auth, serviceMonitorController.update.bind(serviceMonitorController));
+router.delete('/services/:id', ...auth, serviceMonitorController.delete.bind(serviceMonitorController));
+router.get('/system/health', ...auth, serviceMonitorController.getSystemHealth.bind(serviceMonitorController));
+router.get('/users', ...auth, serviceMonitorController.getUsers.bind(serviceMonitorController));
+router.post('/notifications/broadcast', ...auth, serviceMonitorController.broadcastNotification.bind(serviceMonitorController));
+
+export default router;
--- a/backend/src/services/bookstack.service.ts
+++ b/backend/src/services/bookstack.service.ts
@@ -151,4 +151,59 @@ async function searchPages(query: string): Promise<BookStackSearchResult[]> {
  }
 }

-export default { getRecentPages, searchPages };
+export interface BookStackPageDetail {
+  id: number;
+  name: string;
+  slug: string;
+  book_id: number;
+  book_slug: string;
+  chapter_id: number;
+  html: string;
+  created_at: string;
+  updated_at: string;
+  url: string;
+  book?: { name: string };
+  createdBy?: { name: string };
+  updatedBy?: { name: string };
+}
+
+async function getPageById(id: number): Promise<BookStackPageDetail> {
+  const { bookstack } = environment;
+  if (!bookstack.url || !isValidServiceUrl(bookstack.url)) {
+    throw new Error('BOOKSTACK_URL is not configured or is not a valid service URL');
+  }
+
+  try {
+    const response = await axios.get(
+      `${bookstack.url}/api/pages/${id}`,
+      { headers: buildHeaders() },
+    );
+    const page = response.data;
+    return {
+      id: page.id,
+      name: page.name,
+      slug: page.slug,
+      book_id: page.book_id,
+      book_slug: page.book_slug ?? '',
+      chapter_id: page.chapter_id ?? 0,
+      html: page.html ?? '',
+      created_at: page.created_at,
+      updated_at: page.updated_at,
+      url: `${bookstack.url}/books/${page.book_slug}/page/${page.slug}`,
+      book: page.book,
+      createdBy: page.created_by,
+      updatedBy: page.updated_by,
+    };
+  } catch (error) {
+    if (axios.isAxiosError(error)) {
+      logger.error('BookStack getPageById failed', {
+        status: error.response?.status,
+        statusText: error.response?.statusText,
+      });
+    }
+    logger.error('BookStackService.getPageById failed', { error });
+    throw new Error('Failed to fetch BookStack page');
+  }
+}
+
+export default { getRecentPages, searchPages, getPageById };
--- a/backend/src/services/nextcloud.service.ts
+++ b/backend/src/services/nextcloud.service.ts
@@ -127,6 +127,143 @@ async function pollLoginFlow(pollEndpoint: string, pollToken: string): Promise<L
  }
 }

+interface NextcloudChatMessage {
+  id: number;
+  token: string;
+  actorType: string;
+  actorId: string;
+  actorDisplayName: string;
+  message: string;
+  timestamp: number;
+  messageType: string;
+  systemMessage: string;
+}
+
+async function getAllConversations(loginName: string, appPassword: string): Promise<NextcloudConversation[]> {
+  const baseUrl = environment.nextcloudUrl;
+  if (!baseUrl || !isValidServiceUrl(baseUrl)) {
+    throw new Error('NEXTCLOUD_URL is not configured or is not a valid service URL');
+  }
+
+  try {
+    const response = await axios.get(
+      `${baseUrl}/ocs/v2.php/apps/spreed/api/v4/room?format=json`,
+      {
+        headers: {
+          'Authorization': `Basic ${Buffer.from(loginName + ':' + appPassword).toString('base64')}`,
+          'OCS-APIRequest': 'true',
+          'Accept': 'application/json',
+        },
+      },
+    );
+
+    const rooms: any[] = response.data?.ocs?.data ?? [];
+    return rooms
+      .filter((r: any) => r.type !== 4)
+      .sort((a: any, b: any) => (b.lastActivity ?? 0) - (a.lastActivity ?? 0))
+      .map((r: any) => ({
+        token: r.token,
+        displayName: r.displayName,
+        unreadMessages: r.unreadMessages ?? 0,
+        lastActivity: r.lastActivity ?? 0,
+        lastMessage: r.lastMessage
+          ? {
+              text: r.lastMessage.message ?? '',
+              author: r.lastMessage.actorDisplayName ?? '',
+              timestamp: r.lastMessage.timestamp ?? 0,
+            }
+          : null,
+        type: r.type,
+        url: `${baseUrl}/call/${r.token}`,
+      }));
+  } catch (error) {
+    if (axios.isAxiosError(error) && error.response?.status === 401) {
+      const err = new Error('Nextcloud app password is invalid');
+      (err as any).code = 'NEXTCLOUD_AUTH_INVALID';
+      throw err;
+    }
+    if (axios.isAxiosError(error)) {
+      logger.error('Nextcloud getAllConversations failed', {
+        status: error.response?.status,
+        statusText: error.response?.statusText,
+      });
+      throw new Error(`Nextcloud API error: ${error.response?.status ?? 'unknown'}`);
+    }
+    logger.error('NextcloudService.getAllConversations failed', { error });
+    throw new Error('Failed to fetch Nextcloud conversations');
+  }
+}
+
+async function getMessages(token: string, loginName: string, appPassword: string): Promise<NextcloudChatMessage[]> {
+  const baseUrl = environment.nextcloudUrl;
+  if (!baseUrl || !isValidServiceUrl(baseUrl)) {
+    throw new Error('NEXTCLOUD_URL is not configured or is not a valid service URL');
+  }
+
+  const response = await axios.get(
+    `${baseUrl}/ocs/v2.php/apps/spreed/api/v4/chat/${encodeURIComponent(token)}`,
+    {
+      params: { lookIntoFuture: 0, limit: 50, setReadMarker: 0 },
+      headers: {
+        'Authorization': `Basic ${Buffer.from(loginName + ':' + appPassword).toString('base64')}`,
+        'OCS-APIRequest': 'true',
+        'Accept': 'application/json',
+      },
+    },
+  );
+
+  const messages: any[] = response.data?.ocs?.data ?? [];
+  return messages.map((m: any) => ({
+    id: m.id,
+    token: m.token,
+    actorType: m.actorType,
+    actorId: m.actorId,
+    actorDisplayName: m.actorDisplayName,
+    message: m.message,
+    timestamp: m.timestamp,
+    messageType: m.messageType ?? '',
+    systemMessage: m.systemMessage ?? '',
+  }));
+}
+
+async function sendMessage(token: string, message: string, loginName: string, appPassword: string): Promise<void> {
+  const baseUrl = environment.nextcloudUrl;
+  if (!baseUrl || !isValidServiceUrl(baseUrl)) {
+    throw new Error('NEXTCLOUD_URL is not configured or is not a valid service URL');
+  }
+
+  await axios.post(
+    `${baseUrl}/ocs/v2.php/apps/spreed/api/v4/chat/${encodeURIComponent(token)}`,
+    { message },
+    {
+      headers: {
+        'Authorization': `Basic ${Buffer.from(loginName + ':' + appPassword).toString('base64')}`,
+        'OCS-APIRequest': 'true',
+        'Accept': 'application/json',
+        'Content-Type': 'application/json',
+      },
+    },
+  );
+}
+
+async function markAsRead(token: string, loginName: string, appPassword: string): Promise<void> {
+  const baseUrl = environment.nextcloudUrl;
+  if (!baseUrl || !isValidServiceUrl(baseUrl)) {
+    throw new Error('NEXTCLOUD_URL is not configured or is not a valid service URL');
+  }
+
+  await axios.delete(
+    `${baseUrl}/ocs/v2.php/apps/spreed/api/v4/chat/${encodeURIComponent(token)}/read`,
+    {
+      headers: {
+        'Authorization': `Basic ${Buffer.from(loginName + ':' + appPassword).toString('base64')}`,
+        'OCS-APIRequest': 'true',
+        'Accept': 'application/json',
+      },
+    },
+  );
+}
+
 async function getConversations(loginName: string, appPassword: string): Promise<ConversationsResult> {
  const baseUrl = environment.nextcloudUrl;
  if (!baseUrl || !isValidServiceUrl(baseUrl)) {
@@ -193,4 +330,5 @@ async function getConversations(loginName: string, appPassword: string): Promise
  }
 }

-export default { initiateLoginFlow, pollLoginFlow, getConversations };
+export type { NextcloudChatMessage };
+export default { initiateLoginFlow, pollLoginFlow, getConversations, getAllConversations, getMessages, sendMessage, markAsRead };
--- a/backend/src/services/serviceMonitor.service.ts
+++ b/backend/src/services/serviceMonitor.service.ts
@@ -0,0 +1,193 @@
+import axios from 'axios';
+import pool from '../config/database';
+import environment from '../config/environment';
+
+export interface MonitoredService {
+  id: string;
+  name: string;
+  url: string;
+  type: 'internal' | 'custom';
+  is_active: boolean;
+  created_at: string;
+  updated_at: string;
+}
+
+export interface PingResult {
+  name: string;
+  url: string;
+  status: 'up' | 'down';
+  latencyMs: number;
+  error?: string;
+}
+
+export interface StatusSummary {
+  up: number;
+  total: number;
+}
+
+class ServiceMonitorService {
+  async getAllServices(): Promise<MonitoredService[]> {
+    const result = await pool.query(
+      'SELECT * FROM monitored_services ORDER BY created_at'
+    );
+    return result.rows;
+  }
+
+  async createService(name: string, url: string, type: string = 'custom'): Promise<MonitoredService> {
+    const result = await pool.query(
+      `INSERT INTO monitored_services (name, url, type) VALUES ($1, $2, $3) RETURNING *`,
+      [name, url, type]
+    );
+    return result.rows[0];
+  }
+
+  async updateService(id: string, data: Partial<Pick<MonitoredService, 'name' | 'url' | 'is_active'>>): Promise<MonitoredService> {
+    const fields: string[] = [];
+    const values: unknown[] = [];
+    let idx = 1;
+
+    if (data.name !== undefined) {
+      fields.push(`name = $${idx++}`);
+      values.push(data.name);
+    }
+    if (data.url !== undefined) {
+      fields.push(`url = $${idx++}`);
+      values.push(data.url);
+    }
+    if (data.is_active !== undefined) {
+      fields.push(`is_active = $${idx++}`);
+      values.push(data.is_active);
+    }
+
+    if (fields.length === 0) {
+      throw new Error('No fields to update');
+    }
+
+    values.push(id);
+    const result = await pool.query(
+      `UPDATE monitored_services SET ${fields.join(', ')} WHERE id = $${idx} RETURNING *`,
+      values
+    );
+
+    if (result.rowCount === 0) {
+      throw new Error('Service not found');
+    }
+    return result.rows[0];
+  }
+
+  async deleteService(id: string): Promise<boolean> {
+    const result = await pool.query(
+      `DELETE FROM monitored_services WHERE id = $1 AND type = 'custom'`,
+      [id]
+    );
+    return (result.rowCount ?? 0) > 0;
+  }
+
+  async pingService(url: string, headers?: Record<string, string>): Promise<PingResult> {
+    const start = Date.now();
+    try {
+      await axios.get(url, { timeout: 5000, headers });
+      return {
+        name: '',
+        url,
+        status: 'up',
+        latencyMs: Date.now() - start,
+      };
+    } catch (error) {
+      // Treat any HTTP response (even 4xx) as "service is reachable" only for status.php-type endpoints
+      // For API endpoints requiring auth, a 401/403 still means the service is up
+      if (axios.isAxiosError(error) && error.response) {
+        const status = error.response.status;
+        // If we got a response, the service is running (auth errors = service is up)
+        if (headers && (status === 401 || status === 403)) {
+          return {
+            name: '',
+            url,
+            status: 'up',
+            latencyMs: Date.now() - start,
+          };
+        }
+      }
+      return {
+        name: '',
+        url,
+        status: 'down',
+        latencyMs: Date.now() - start,
+        error: axios.isAxiosError(error)
+          ? `${error.code ?? 'ERROR'}: ${error.message}`
+          : String(error),
+      };
+    }
+  }
+
+  async pingAll(): Promise<PingResult[]> {
+    const services = await this.getAllServices();
+    const activeServices = services.filter((s) => s.is_active);
+
+    const internalServices = this.getInternalServices();
+
+    const allTargets = [
+      ...activeServices.map((s) => ({ name: s.name, url: s.url, pingUrl: s.url, headers: undefined as Record<string, string> | undefined })),
+      ...internalServices,
+    ];
+
+    const results = await Promise.all(
+      allTargets.map(async (target) => {
+        const result = await this.pingService(target.pingUrl, target.headers);
+        result.name = target.name;
+        result.url = target.url;
+        return result;
+      })
+    );
+
+    return results;
+  }
+
+  async getStatusSummary(): Promise<StatusSummary> {
+    const results = await this.pingAll();
+    return {
+      up: results.filter((r) => r.status === 'up').length,
+      total: results.length,
+    };
+  }
+
+  private getInternalServices(): Array<{ name: string; url: string; pingUrl: string; headers?: Record<string, string> }> {
+    const internal: Array<{ name: string; url: string; pingUrl: string; headers?: Record<string, string> }> = [];
+
+    const { bookstack, vikunja, nextcloudUrl } = environment;
+
+    if (nextcloudUrl) {
+      internal.push({
+        name: 'Nextcloud',
+        url: nextcloudUrl,
+        pingUrl: `${nextcloudUrl}/status.php`,
+      });
+    }
+
+    if (bookstack.url) {
+      internal.push({
+        name: 'BookStack',
+        url: bookstack.url,
+        pingUrl: `${bookstack.url}/api/pages?count=1`,
+        headers: {
+          'Authorization': `Token ${bookstack.tokenId}:${bookstack.tokenSecret}`,
+        },
+      });
+    }
+
+    if (vikunja.url) {
+      internal.push({
+        name: 'Vikunja',
+        url: vikunja.url,
+        pingUrl: `${vikunja.url}/api/v1/tasks/all?per_page=1`,
+        headers: {
+          'Authorization': `Bearer ${vikunja.apiToken}`,
+        },
+      });
+    }
+
+    return internal;
+  }
+}
+
+export default new ServiceMonitorService();
--- a/frontend/package.json
+++ b/frontend/package.json
@@ -23,6 +23,7 @@
    "react": "^18.2.0",
    "react-dom": "^18.2.0",
    "react-router-dom": "^6.20.0",
+    "dompurify": "^2.5.8",
    "recharts": "^2.12.7"
  },
  "devDependencies": {
--- a/frontend/src/App.tsx
+++ b/frontend/src/App.tsx
@@ -24,6 +24,8 @@ import Kalender from './pages/Kalender';
 import UebungDetail from './pages/UebungDetail';
 import Veranstaltungen from './pages/Veranstaltungen';
 import VeranstaltungKategorien from './pages/VeranstaltungKategorien';
+import Wissen from './pages/Wissen';
+import AdminDashboard from './pages/AdminDashboard';
 import NotFound from './pages/NotFound';

 function App() {
@@ -203,6 +205,22 @@ function App() {
                </ProtectedRoute>
              }
            />
+            <Route
+              path="/wissen"
+              element={
+                <ProtectedRoute>
+                  <Wissen />
+                </ProtectedRoute>
+              }
+            />
+            <Route
+              path="/admin"
+              element={
+                <ProtectedRoute>
+                  <AdminDashboard />
+                </ProtectedRoute>
+              }
+            />
            <Route path="*" element={<NotFound />} />
          </Routes>
        </AuthProvider>
--- a/frontend/src/components/admin/NotificationBroadcastTab.tsx
+++ b/frontend/src/components/admin/NotificationBroadcastTab.tsx
@@ -0,0 +1,131 @@
+import { useState } from 'react';
+import {
+  Box,
+  TextField,
+  Button,
+  MenuItem,
+  Typography,
+  Dialog,
+  DialogTitle,
+  DialogContent,
+  DialogContentText,
+  DialogActions,
+  CircularProgress,
+} from '@mui/material';
+import SendIcon from '@mui/icons-material/Send';
+import { useMutation } from '@tanstack/react-query';
+import { adminApi } from '../../services/admin';
+import { useNotification } from '../../contexts/NotificationContext';
+import type { BroadcastPayload } from '../../types/admin.types';
+
+function NotificationBroadcastTab() {
+  const { showSuccess, showError } = useNotification();
+  const [titel, setTitel] = useState('');
+  const [nachricht, setNachricht] = useState('');
+  const [schwere, setSchwere] = useState<'info' | 'warnung' | 'fehler'>('info');
+  const [targetGroup, setTargetGroup] = useState('');
+  const [confirmOpen, setConfirmOpen] = useState(false);
+
+  const broadcastMutation = useMutation({
+    mutationFn: (data: BroadcastPayload) => adminApi.broadcast(data),
+    onSuccess: (result) => {
+      showSuccess(`Benachrichtigung an ${result.sent} Benutzer gesendet`);
+      setTitel('');
+      setNachricht('');
+      setSchwere('info');
+      setTargetGroup('');
+    },
+    onError: () => {
+      showError('Fehler beim Senden der Benachrichtigung');
+    },
+  });
+
+  const handleSubmit = () => {
+    setConfirmOpen(true);
+  };
+
+  const handleConfirm = () => {
+    setConfirmOpen(false);
+    broadcastMutation.mutate({
+      titel,
+      nachricht,
+      schwere,
+      ...(targetGroup.trim() ? { targetGroup: targetGroup.trim() } : {}),
+    });
+  };
+
+  return (
+    <Box sx={{ maxWidth: 600 }}>
+      <Typography variant="h6" sx={{ mb: 2 }}>Benachrichtigung senden</Typography>
+
+      <TextField
+        label="Titel"
+        fullWidth
+        value={titel}
+        onChange={(e) => setTitel(e.target.value)}
+        sx={{ mb: 2 }}
+        inputProps={{ maxLength: 200 }}
+      />
+
+      <TextField
+        label="Nachricht"
+        fullWidth
+        multiline
+        rows={4}
+        value={nachricht}
+        onChange={(e) => setNachricht(e.target.value)}
+        sx={{ mb: 2 }}
+        inputProps={{ maxLength: 2000 }}
+      />
+
+      <TextField
+        select
+        label="Schwere"
+        fullWidth
+        value={schwere}
+        onChange={(e) => setSchwere(e.target.value as 'info' | 'warnung' | 'fehler')}
+        sx={{ mb: 2 }}
+      >
+        <MenuItem value="info">Info</MenuItem>
+        <MenuItem value="warnung">Warnung</MenuItem>
+        <MenuItem value="fehler">Fehler</MenuItem>
+      </TextField>
+
+      <TextField
+        label="Zielgruppe (optional)"
+        fullWidth
+        value={targetGroup}
+        onChange={(e) => setTargetGroup(e.target.value)}
+        helperText="Leer lassen um an alle aktiven Benutzer zu senden"
+        sx={{ mb: 3 }}
+      />
+
+      <Button
+        variant="contained"
+        startIcon={broadcastMutation.isPending ? <CircularProgress size={18} color="inherit" /> : <SendIcon />}
+        onClick={handleSubmit}
+        disabled={!titel.trim() || !nachricht.trim() || broadcastMutation.isPending}
+      >
+        Senden
+      </Button>
+
+      <Dialog open={confirmOpen} onClose={() => setConfirmOpen(false)}>
+        <DialogTitle>Benachrichtigung senden?</DialogTitle>
+        <DialogContent>
+          <DialogContentText>
+            Sind Sie sicher, dass Sie diese Benachrichtigung
+            {targetGroup.trim() ? ` an die Gruppe "${targetGroup.trim()}"` : ' an alle aktiven Benutzer'} senden moechten?
+          </DialogContentText>
+        </DialogContent>
+        <DialogActions>
+          <Button onClick={() => setConfirmOpen(false)}>Abbrechen</Button>
+          <Button onClick={handleConfirm} variant="contained" color="primary">
+            Bestaetigen
+          </Button>
+        </DialogActions>
+      </Dialog>
+    </Box>
+  );
+}
+
+export default NotificationBroadcastTab;
--- a/frontend/src/components/admin/ServiceManagerTab.tsx
+++ b/frontend/src/components/admin/ServiceManagerTab.tsx
@@ -0,0 +1,205 @@
+import { useState } from 'react';
+import {
+  Box,
+  Table,
+  TableBody,
+  TableCell,
+  TableContainer,
+  TableHead,
+  TableRow,
+  Paper,
+  Button,
+  Dialog,
+  DialogTitle,
+  DialogContent,
+  DialogActions,
+  TextField,
+  IconButton,
+  Typography,
+  CircularProgress,
+} from '@mui/material';
+import DeleteIcon from '@mui/icons-material/Delete';
+import AddIcon from '@mui/icons-material/Add';
+import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query';
+import { adminApi } from '../../services/admin';
+import type { PingResult } from '../../types/admin.types';
+
+function ServiceManagerTab() {
+  const queryClient = useQueryClient();
+  const [dialogOpen, setDialogOpen] = useState(false);
+  const [newName, setNewName] = useState('');
+  const [newUrl, setNewUrl] = useState('');
+
+  const { data: services, isLoading: servicesLoading } = useQuery({
+    queryKey: ['admin', 'services'],
+    queryFn: adminApi.getServices,
+    refetchInterval: 15000,
+  });
+
+  const { data: pingResults, isLoading: pingLoading } = useQuery({
+    queryKey: ['admin', 'services', 'ping'],
+    queryFn: adminApi.pingAll,
+    refetchInterval: 15000,
+  });
+
+  const createMutation = useMutation({
+    mutationFn: (data: { name: string; url: string }) => adminApi.createService(data),
+    onSuccess: () => {
+      queryClient.invalidateQueries({ queryKey: ['admin', 'services'] });
+      setDialogOpen(false);
+      setNewName('');
+      setNewUrl('');
+    },
+  });
+
+  const deleteMutation = useMutation({
+    mutationFn: (id: string) => adminApi.deleteService(id),
+    onSuccess: () => {
+      queryClient.invalidateQueries({ queryKey: ['admin', 'services'] });
+    },
+  });
+
+  const getPingForUrl = (url: string): PingResult | undefined => {
+    return pingResults?.find((p) => p.url === url);
+  };
+
+  const handleCreate = () => {
+    if (newName.trim() && newUrl.trim()) {
+      createMutation.mutate({ name: newName.trim(), url: newUrl.trim() });
+    }
+  };
+
+  if (servicesLoading) {
+    return <Box sx={{ display: 'flex', justifyContent: 'center', p: 4 }}><CircularProgress /></Box>;
+  }
+
+  const allItems = [
+    ...(services ?? []).map((s) => ({
+      id: s.id,
+      name: s.name,
+      url: s.url,
+      type: s.type,
+      isCustom: s.type === 'custom',
+    })),
+  ];
+
+  // Also include internal services from ping results that aren't in the DB
+  if (pingResults) {
+    for (const pr of pingResults) {
+      if (!allItems.find((item) => item.url === pr.url)) {
+        allItems.push({
+          id: pr.url,
+          name: pr.name,
+          url: pr.url,
+          type: 'internal' as const,
+          isCustom: false,
+        });
+      }
+    }
+  }
+
+  return (
+    <Box>
+      <Box sx={{ display: 'flex', justifyContent: 'space-between', alignItems: 'center', mb: 2 }}>
+        <Typography variant="h6">Service Monitor</Typography>
+        <Button startIcon={<AddIcon />} variant="contained" onClick={() => setDialogOpen(true)}>
+          Service hinzufuegen
+        </Button>
+      </Box>
+
+      <TableContainer component={Paper}>
+        <Table>
+          <TableHead>
+            <TableRow>
+              <TableCell>Status</TableCell>
+              <TableCell>Name</TableCell>
+              <TableCell>URL</TableCell>
+              <TableCell>Typ</TableCell>
+              <TableCell>Latenz</TableCell>
+              <TableCell>Aktionen</TableCell>
+            </TableRow>
+          </TableHead>
+          <TableBody>
+            {allItems.map((item) => {
+              const ping = getPingForUrl(item.url);
+              return (
+                <TableRow key={item.id}>
+                  <TableCell>
+                    {pingLoading ? (
+                      <CircularProgress size={16} />
+                    ) : (
+                      <Box
+                        sx={{
+                          width: 12,
+                          height: 12,
+                          borderRadius: '50%',
+                          bgcolor: ping?.status === 'up' ? 'success.main' : ping ? 'error.main' : 'grey.400',
+                        }}
+                      />
+                    )}
+                  </TableCell>
+                  <TableCell>{item.name}</TableCell>
+                  <TableCell sx={{ maxWidth: 300, overflow: 'hidden', textOverflow: 'ellipsis' }}>
+                    {item.url}
+                  </TableCell>
+                  <TableCell>{item.type}</TableCell>
+                  <TableCell>{ping ? `${ping.latencyMs}ms` : '-'}</TableCell>
+                  <TableCell>
+                    {item.isCustom && (
+                      <IconButton
+                        size="small"
+                        color="error"
+                        onClick={() => deleteMutation.mutate(item.id)}
+                        disabled={deleteMutation.isPending}
+                      >
+                        <DeleteIcon fontSize="small" />
+                      </IconButton>
+                    )}
+                  </TableCell>
+                </TableRow>
+              );
+            })}
+            {allItems.length === 0 && (
+              <TableRow>
+                <TableCell colSpan={6} align="center">Keine Services konfiguriert</TableCell>
+              </TableRow>
+            )}
+          </TableBody>
+        </Table>
+      </TableContainer>
+
+      <Dialog open={dialogOpen} onClose={() => setDialogOpen(false)} maxWidth="sm" fullWidth>
+        <DialogTitle>Neuen Service hinzufuegen</DialogTitle>
+        <DialogContent>
+          <TextField
+            autoFocus
+            margin="dense"
+            label="Name"
+            fullWidth
+            value={newName}
+            onChange={(e) => setNewName(e.target.value)}
+          />
+          <TextField
+            margin="dense"
+            label="URL"
+            fullWidth
+            value={newUrl}
+            onChange={(e) => setNewUrl(e.target.value)}
+          />
+        </DialogContent>
+        <DialogActions>
+          <Button onClick={() => setDialogOpen(false)}>Abbrechen</Button>
+          <Button
+            onClick={handleCreate}
+            variant="contained"
+            disabled={createMutation.isPending || !newName.trim() || !newUrl.trim()}
+          >
+            Erstellen
+          </Button>
+        </DialogActions>
+      </Dialog>
+    </Box>
+  );
+}
+
+export default ServiceManagerTab;
--- a/frontend/src/components/admin/SystemHealthTab.tsx
+++ b/frontend/src/components/admin/SystemHealthTab.tsx
@@ -0,0 +1,117 @@
+import { Box, Card, CardContent, Typography, Chip, LinearProgress, CircularProgress, Grid } from '@mui/material';
+import { useQuery } from '@tanstack/react-query';
+import { adminApi } from '../../services/admin';
+
+function formatUptime(seconds: number): string {
+  const days = Math.floor(seconds / 86400);
+  const hours = Math.floor((seconds % 86400) / 3600);
+  const mins = Math.floor((seconds % 3600) / 60);
+  const parts: string[] = [];
+  if (days > 0) parts.push(`${days}d`);
+  if (hours > 0) parts.push(`${hours}h`);
+  parts.push(`${mins}m`);
+  return parts.join(' ');
+}
+
+function formatBytes(bytes: number): string {
+  const mb = bytes / (1024 * 1024);
+  return `${mb.toFixed(1)} MB`;
+}
+
+function SystemHealthTab() {
+  const { data: health, isLoading } = useQuery({
+    queryKey: ['admin', 'system', 'health'],
+    queryFn: adminApi.getSystemHealth,
+    refetchInterval: 30000,
+  });
+
+  if (isLoading || !health) {
+    return <Box sx={{ display: 'flex', justifyContent: 'center', p: 4 }}><CircularProgress /></Box>;
+  }
+
+  const heapPercent = (health.memoryUsage.heapUsed / health.memoryUsage.heapTotal) * 100;
+
+  return (
+    <Box>
+      <Typography variant="h6" sx={{ mb: 2 }}>Systemstatus</Typography>
+      <Grid container spacing={2}>
+        <Grid item xs={12} sm={6} md={4}>
+          <Card>
+            <CardContent>
+              <Typography color="text.secondary" gutterBottom>Node.js Version</Typography>
+              <Chip label={health.nodeVersion} color="primary" />
+            </CardContent>
+          </Card>
+        </Grid>
+
+        <Grid item xs={12} sm={6} md={4}>
+          <Card>
+            <CardContent>
+              <Typography color="text.secondary" gutterBottom>Uptime</Typography>
+              <Typography variant="h5">{formatUptime(health.uptime)}</Typography>
+            </CardContent>
+          </Card>
+        </Grid>
+
+        <Grid item xs={12} sm={6} md={4}>
+          <Card>
+            <CardContent>
+              <Typography color="text.secondary" gutterBottom>Datenbank</Typography>
+              <Box sx={{ display: 'flex', alignItems: 'center', gap: 1 }}>
+                <Box
+                  sx={{
+                    width: 12,
+                    height: 12,
+                    borderRadius: '50%',
+                    bgcolor: health.dbStatus ? 'success.main' : 'error.main',
+                  }}
+                />
+                <Typography>{health.dbStatus ? 'Verbunden' : 'Nicht erreichbar'}</Typography>
+              </Box>
+              <Typography variant="body2" color="text.secondary" sx={{ mt: 1 }}>
+                Groesse: {formatBytes(Number(health.dbSize))}
+              </Typography>
+            </CardContent>
+          </Card>
+        </Grid>
+
+        <Grid item xs={12} sm={6} md={4}>
+          <Card>
+            <CardContent>
+              <Typography color="text.secondary" gutterBottom>Heap Speicher</Typography>
+              <Typography variant="body2">
+                {formatBytes(health.memoryUsage.heapUsed)} / {formatBytes(health.memoryUsage.heapTotal)}
+              </Typography>
+              <LinearProgress
+                variant="determinate"
+                value={heapPercent}
+                sx={{ mt: 1, height: 8, borderRadius: 4 }}
+                color={heapPercent > 85 ? 'error' : heapPercent > 70 ? 'warning' : 'primary'}
+              />
+            </CardContent>
+          </Card>
+        </Grid>
+
+        <Grid item xs={12} sm={6} md={4}>
+          <Card>
+            <CardContent>
+              <Typography color="text.secondary" gutterBottom>RSS Speicher</Typography>
+              <Typography variant="h5">{formatBytes(health.memoryUsage.rss)}</Typography>
+            </CardContent>
+          </Card>
+        </Grid>
+
+        <Grid item xs={12} sm={6} md={4}>
+          <Card>
+            <CardContent>
+              <Typography color="text.secondary" gutterBottom>External Speicher</Typography>
+              <Typography variant="h5">{formatBytes(health.memoryUsage.external)}</Typography>
+            </CardContent>
+          </Card>
+        </Grid>
+      </Grid>
+    </Box>
+  );
+}
+
+export default SystemHealthTab;
--- a/frontend/src/components/admin/UserOverviewTab.tsx
+++ b/frontend/src/components/admin/UserOverviewTab.tsx
@@ -0,0 +1,166 @@
+import { useState, useMemo } from 'react';
+import {
+  Box,
+  Table,
+  TableBody,
+  TableCell,
+  TableContainer,
+  TableHead,
+  TableRow,
+  TableSortLabel,
+  Paper,
+  TextField,
+  Chip,
+  Typography,
+  CircularProgress,
+} from '@mui/material';
+import { useQuery } from '@tanstack/react-query';
+import { adminApi } from '../../services/admin';
+import type { UserOverview } from '../../types/admin.types';
+
+type SortKey = 'name' | 'email' | 'role' | 'is_active' | 'last_login_at';
+type SortDir = 'asc' | 'desc';
+
+function formatRelativeTime(dateStr: string | null): string {
+  if (!dateStr) return 'Nie';
+  const date = new Date(dateStr);
+  const now = new Date();
+  const diffMs = now.getTime() - date.getTime();
+  const diffMins = Math.floor(diffMs / 60000);
+  if (diffMins < 1) return 'Gerade eben';
+  if (diffMins < 60) return `vor ${diffMins}m`;
+  const diffHours = Math.floor(diffMins / 60);
+  if (diffHours < 24) return `vor ${diffHours}h`;
+  const diffDays = Math.floor(diffHours / 24);
+  return `vor ${diffDays}d`;
+}
+
+function UserOverviewTab() {
+  const [search, setSearch] = useState('');
+  const [sortKey, setSortKey] = useState<SortKey>('name');
+  const [sortDir, setSortDir] = useState<SortDir>('asc');
+
+  const { data: users, isLoading } = useQuery({
+    queryKey: ['admin', 'users'],
+    queryFn: adminApi.getUsers,
+  });
+
+  const handleSort = (key: SortKey) => {
+    if (sortKey === key) {
+      setSortDir(sortDir === 'asc' ? 'desc' : 'asc');
+    } else {
+      setSortKey(key);
+      setSortDir('asc');
+    }
+  };
+
+  const filtered = useMemo(() => {
+    if (!users) return [];
+    const q = search.toLowerCase();
+    let result = users.filter(
+      (u) => u.name?.toLowerCase().includes(q) || u.email?.toLowerCase().includes(q)
+    );
+
+    result.sort((a, b) => {
+      const valA = a[sortKey];
+      const valB = b[sortKey];
+      let cmp = 0;
+      if (valA == null && valB == null) cmp = 0;
+      else if (valA == null) cmp = -1;
+      else if (valB == null) cmp = 1;
+      else if (typeof valA === 'string' && typeof valB === 'string') {
+        cmp = valA.localeCompare(valB);
+      } else if (typeof valA === 'boolean' && typeof valB === 'boolean') {
+        cmp = valA === valB ? 0 : valA ? 1 : -1;
+      }
+      return sortDir === 'asc' ? cmp : -cmp;
+    });
+    return result;
+  }, [users, search, sortKey, sortDir]);
+
+  if (isLoading) {
+    return <Box sx={{ display: 'flex', justifyContent: 'center', p: 4 }}><CircularProgress /></Box>;
+  }
+
+  return (
+    <Box>
+      <Box sx={{ display: 'flex', justifyContent: 'space-between', alignItems: 'center', mb: 2 }}>
+        <Typography variant="h6">Benutzer ({filtered.length})</Typography>
+        <TextField
+          size="small"
+          placeholder="Suche nach Name oder E-Mail..."
+          value={search}
+          onChange={(e) => setSearch(e.target.value)}
+          sx={{ minWidth: 280 }}
+        />
+      </Box>
+
+      <TableContainer component={Paper}>
+        <Table>
+          <TableHead>
+            <TableRow>
+              <TableCell>
+                <TableSortLabel active={sortKey === 'name'} direction={sortKey === 'name' ? sortDir : 'asc'} onClick={() => handleSort('name')}>
+                  Name
+                </TableSortLabel>
+              </TableCell>
+              <TableCell>
+                <TableSortLabel active={sortKey === 'email'} direction={sortKey === 'email' ? sortDir : 'asc'} onClick={() => handleSort('email')}>
+                  E-Mail
+                </TableSortLabel>
+              </TableCell>
+              <TableCell>
+                <TableSortLabel active={sortKey === 'role'} direction={sortKey === 'role' ? sortDir : 'asc'} onClick={() => handleSort('role')}>
+                  Rolle
+                </TableSortLabel>
+              </TableCell>
+              <TableCell>Gruppen</TableCell>
+              <TableCell>
+                <TableSortLabel active={sortKey === 'is_active'} direction={sortKey === 'is_active' ? sortDir : 'asc'} onClick={() => handleSort('is_active')}>
+                  Status
+                </TableSortLabel>
+              </TableCell>
+              <TableCell>
+                <TableSortLabel active={sortKey === 'last_login_at'} direction={sortKey === 'last_login_at' ? sortDir : 'asc'} onClick={() => handleSort('last_login_at')}>
+                  Letzter Login
+                </TableSortLabel>
+              </TableCell>
+            </TableRow>
+          </TableHead>
+          <TableBody>
+            {filtered.map((user: UserOverview) => (
+              <TableRow key={user.id}>
+                <TableCell>{user.name}</TableCell>
+                <TableCell>{user.email}</TableCell>
+                <TableCell>
+                  <Chip
+                    label={user.role}
+                    size="small"
+                    color={user.role === 'admin' ? 'error' : 'default'}
+                  />
+                </TableCell>
+                <TableCell>
+                  <Box sx={{ display: 'flex', gap: 0.5, flexWrap: 'wrap' }}>
+                    {(user.groups ?? []).map((g) => (
+                      <Chip key={g} label={g} size="small" variant="outlined" />
+                    ))}
+                  </Box>
+                </TableCell>
+                <TableCell>
+                  <Chip
+                    label={user.is_active ? 'Aktiv' : 'Inaktiv'}
+                    size="small"
+                    color={user.is_active ? 'success' : 'default'}
+                  />
+                </TableCell>
+                <TableCell>{formatRelativeTime(user.last_login_at)}</TableCell>
+              </TableRow>
+            ))}
+          </TableBody>
+        </Table>
+      </TableContainer>
+    </Box>
+  );
+}
+
+export default UserOverviewTab;
--- a/frontend/src/components/chat/ChatMessage.tsx
+++ b/frontend/src/components/chat/ChatMessage.tsx
@@ -0,0 +1,72 @@
+import React from 'react';
+import Box from '@mui/material/Box';
+import Typography from '@mui/material/Typography';
+import Paper from '@mui/material/Paper';
+import type { NextcloudMessage } from '../../types/nextcloud.types';
+
+interface ChatMessageProps {
+  message: NextcloudMessage;
+  isOwnMessage: boolean;
+}
+
+const ChatMessage: React.FC<ChatMessageProps> = ({ message, isOwnMessage }) => {
+  const time = new Date(message.timestamp * 1000).toLocaleTimeString('de-DE', {
+    hour: '2-digit',
+    minute: '2-digit',
+  });
+
+  if (message.systemMessage) {
+    return (
+      <Box sx={{ display: 'flex', justifyContent: 'center', my: 0.5 }}>
+        <Typography variant="caption" sx={{ fontStyle: 'italic', color: 'text.secondary' }}>
+          {message.message} - {time}
+        </Typography>
+      </Box>
+    );
+  }
+
+  return (
+    <Box
+      sx={{
+        display: 'flex',
+        justifyContent: isOwnMessage ? 'flex-end' : 'flex-start',
+        my: 0.5,
+        px: 1,
+      }}
+    >
+      <Paper
+        elevation={0}
+        sx={{
+          px: 1.5,
+          py: 0.75,
+          maxWidth: '80%',
+          bgcolor: isOwnMessage ? 'primary.main' : (theme) => theme.palette.mode === 'dark' ? 'grey.800' : 'grey.200',
+          color: isOwnMessage ? 'primary.contrastText' : 'text.primary',
+          borderRadius: 2,
+        }}
+      >
+        {!isOwnMessage && (
+          <Typography variant="caption" sx={{ fontWeight: 600, display: 'block' }}>
+            {message.actorDisplayName}
+          </Typography>
+        )}
+        <Typography variant="body2" sx={{ whiteSpace: 'pre-wrap', wordBreak: 'break-word' }}>
+          {message.message}
+        </Typography>
+        <Typography
+          variant="caption"
+          sx={{
+            display: 'block',
+            textAlign: 'right',
+            mt: 0.25,
+            opacity: 0.7,
+          }}
+        >
+          {time}
+        </Typography>
+      </Paper>
+    </Box>
+  );
+};
+
+export default ChatMessage;
--- a/frontend/src/components/chat/ChatMessageView.tsx
+++ b/frontend/src/components/chat/ChatMessageView.tsx
@@ -0,0 +1,119 @@
+import React, { useEffect, useRef, useState } from 'react';
+import Box from '@mui/material/Box';
+import TextField from '@mui/material/TextField';
+import IconButton from '@mui/material/IconButton';
+import Typography from '@mui/material/Typography';
+import SendIcon from '@mui/icons-material/Send';
+import ArrowBackIcon from '@mui/icons-material/ArrowBack';
+import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query';
+import { nextcloudApi } from '../../services/nextcloud';
+import { useChat } from '../../contexts/ChatContext';
+import { useLayout } from '../../contexts/LayoutContext';
+import ChatMessage from './ChatMessage';
+
+const ChatMessageView: React.FC = () => {
+  const { selectedRoomToken, selectRoom, rooms, loginName } = useChat();
+  const { chatPanelOpen } = useLayout();
+  const queryClient = useQueryClient();
+  const messagesEndRef = useRef<HTMLDivElement>(null);
+  const [input, setInput] = useState('');
+
+  const room = rooms.find((r) => r.token === selectedRoomToken);
+
+  const { data: messages } = useQuery({
+    queryKey: ['nextcloud', 'messages', selectedRoomToken],
+    queryFn: () => nextcloudApi.getMessages(selectedRoomToken!),
+    enabled: !!selectedRoomToken && chatPanelOpen,
+    refetchInterval: 5000,
+  });
+
+  const sendMutation = useMutation({
+    mutationFn: (message: string) => nextcloudApi.sendMessage(selectedRoomToken!, message),
+    onSuccess: () => {
+      queryClient.invalidateQueries({ queryKey: ['nextcloud', 'messages', selectedRoomToken] });
+      queryClient.invalidateQueries({ queryKey: ['nextcloud', 'rooms'] });
+    },
+  });
+
+  useEffect(() => {
+    if (selectedRoomToken && chatPanelOpen) {
+      nextcloudApi.markAsRead(selectedRoomToken).then(() => {
+        queryClient.invalidateQueries({ queryKey: ['nextcloud', 'rooms'] });
+      }).catch(() => {});
+    }
+  }, [selectedRoomToken, chatPanelOpen, queryClient]);
+
+  useEffect(() => {
+    messagesEndRef.current?.scrollIntoView({ behavior: 'smooth' });
+  }, [messages]);
+
+  const handleSend = () => {
+    const trimmed = input.trim();
+    if (!trimmed || !selectedRoomToken) return;
+    sendMutation.mutate(trimmed);
+    setInput('');
+  };
+
+  const handleKeyDown = (e: React.KeyboardEvent) => {
+    if (e.key === 'Enter' && !e.shiftKey) {
+      e.preventDefault();
+      handleSend();
+    }
+  };
+
+  if (!selectedRoomToken) {
+    return (
+      <Box sx={{ display: 'flex', alignItems: 'center', justifyContent: 'center', flex: 1 }}>
+        <Typography color="text.secondary" variant="body2">
+          Raum auswählen
+        </Typography>
+      </Box>
+    );
+  }
+
+  return (
+    <Box sx={{ display: 'flex', flexDirection: 'column', flex: 1, minHeight: 0 }}>
+      <Box sx={{ px: 1.5, py: 1, borderBottom: 1, borderColor: 'divider', display: 'flex', alignItems: 'center', gap: 1 }}>
+        <IconButton size="small" onClick={() => selectRoom(null)}>
+          <ArrowBackIcon fontSize="small" />
+        </IconButton>
+        <Typography variant="subtitle2" noWrap>
+          {room?.displayName ?? selectedRoomToken}
+        </Typography>
+      </Box>
+
+      <Box sx={{ flex: 1, overflow: 'auto', py: 1 }}>
+        {messages?.map((msg) => (
+          <ChatMessage
+            key={msg.id}
+            message={msg}
+            isOwnMessage={msg.actorType === 'users' && msg.actorId === loginName}
+          />
+        ))}
+        <div ref={messagesEndRef} />
+      </Box>
+
+      <Box sx={{ p: 1, borderTop: 1, borderColor: 'divider', display: 'flex', gap: 0.5 }}>
+        <TextField
+          size="small"
+          fullWidth
+          placeholder="Nachricht..."
+          value={input}
+          onChange={(e) => setInput(e.target.value)}
+          onKeyDown={handleKeyDown}
+          multiline
+          maxRows={3}
+        />
+        <IconButton
+          color="primary"
+          onClick={handleSend}
+          disabled={!input.trim() || sendMutation.isPending}
+        >
+          <SendIcon />
+        </IconButton>
+      </Box>
+    </Box>
+  );
+};
+
+export default ChatMessageView;
--- a/frontend/src/components/chat/ChatPanel.tsx
+++ b/frontend/src/components/chat/ChatPanel.tsx
@@ -0,0 +1,93 @@
+import React from 'react';
+import Box from '@mui/material/Box';
+import Paper from '@mui/material/Paper';
+import IconButton from '@mui/material/IconButton';
+import ChatIcon from '@mui/icons-material/Chat';
+import Typography from '@mui/material/Typography';
+import { useLayout } from '../../contexts/LayoutContext';
+import { ChatProvider, useChat } from '../../contexts/ChatContext';
+import ChatRoomList from './ChatRoomList';
+import ChatMessageView from './ChatMessageView';
+
+const ChatPanelInner: React.FC = () => {
+  const { chatPanelOpen, setChatPanelOpen } = useLayout();
+  const { selectedRoomToken, connected } = useChat();
+
+  if (!chatPanelOpen) {
+    return (
+      <Paper
+        elevation={2}
+        sx={{
+          width: 60,
+          height: '100%',
+          display: 'flex',
+          flexDirection: 'column',
+          alignItems: 'center',
+          pt: 1,
+          flexShrink: 0,
+          transition: 'width 0.2s ease',
+        }}
+      >
+        <IconButton onClick={() => setChatPanelOpen(true)}>
+          <ChatIcon />
+        </IconButton>
+      </Paper>
+    );
+  }
+
+  return (
+    <Paper
+      elevation={2}
+      sx={{
+        width: 360,
+        height: '100%',
+        display: 'flex',
+        flexDirection: 'column',
+        flexShrink: 0,
+        transition: 'width 0.2s ease',
+        overflow: 'hidden',
+      }}
+    >
+      <Box
+        sx={{
+          px: 1.5,
+          py: 1,
+          borderBottom: 1,
+          borderColor: 'divider',
+          display: 'flex',
+          alignItems: 'center',
+          justifyContent: 'space-between',
+        }}
+      >
+        <Typography variant="subtitle1" fontWeight={600}>
+          Chat
+        </Typography>
+        <IconButton size="small" onClick={() => setChatPanelOpen(false)}>
+          <ChatIcon fontSize="small" />
+        </IconButton>
+      </Box>
+
+      {!connected ? (
+        <Box sx={{ p: 2 }}>
+          <Typography variant="body2" color="text.secondary">
+            Nextcloud nicht verbunden. Bitte verbinden Sie sich in den Einstellungen.
+          </Typography>
+        </Box>
+      ) : selectedRoomToken ? (
+        <ChatMessageView />
+      ) : (
+        <ChatRoomList />
+      )}
+    </Paper>
+  );
+};
+
+const ChatPanel: React.FC = () => {
+  return (
+    <ChatProvider>
+      <ChatPanelInner />
+    </ChatProvider>
+  );
+};
+
+export default ChatPanel;
--- a/frontend/src/components/chat/ChatRoomList.tsx
+++ b/frontend/src/components/chat/ChatRoomList.tsx
@@ -0,0 +1,48 @@
+import React from 'react';
+import Box from '@mui/material/Box';
+import List from '@mui/material/List';
+import ListItemButton from '@mui/material/ListItemButton';
+import Badge from '@mui/material/Badge';
+import Typography from '@mui/material/Typography';
+import { useChat } from '../../contexts/ChatContext';
+
+const ChatRoomList: React.FC = () => {
+  const { rooms, selectedRoomToken, selectRoom } = useChat();
+
+  return (
+    <Box sx={{ overflow: 'auto', flex: 1 }}>
+      <List disablePadding>
+        {rooms.map((room) => (
+          <ListItemButton
+            key={room.token}
+            selected={room.token === selectedRoomToken}
+            onClick={() => selectRoom(room.token)}
+            sx={{ py: 1, px: 1.5 }}
+          >
+            <Box sx={{ flex: 1, minWidth: 0 }}>
+              <Box sx={{ display: 'flex', alignItems: 'center', justifyContent: 'space-between' }}>
+                <Typography variant="subtitle2" noWrap sx={{ flex: 1 }}>
+                  {room.displayName}
+                </Typography>
+                {room.unreadMessages > 0 && (
+                  <Badge
+                    badgeContent={room.unreadMessages}
+                    color="primary"
+                    sx={{ ml: 1 }}
+                  />
+                )}
+              </Box>
+              {room.lastMessage && (
+                <Typography variant="caption" color="text.secondary" noWrap>
+                  {room.lastMessage.author}: {room.lastMessage.text}
+                </Typography>
+              )}
+            </Box>
+          </ListItemButton>
+        ))}
+      </List>
+    </Box>
+  );
+};
+
+export default ChatRoomList;
--- a/frontend/src/components/dashboard/AdminStatusWidget.tsx
+++ b/frontend/src/components/dashboard/AdminStatusWidget.tsx
@@ -0,0 +1,67 @@
+import { Card, CardContent, Typography, Box, Chip } from '@mui/material';
+import { useQuery } from '@tanstack/react-query';
+import { useNavigate } from 'react-router-dom';
+import { MonitorHeartOutlined } from '@mui/icons-material';
+import { adminApi } from '../../services/admin';
+import { useCountUp } from '../../hooks/useCountUp';
+import { useAuth } from '../../contexts/AuthContext';
+
+function AdminStatusWidget() {
+  const { user } = useAuth();
+  const navigate = useNavigate();
+
+  const isAdmin = user?.groups?.includes('dashboard_admin') ?? false;
+
+  const { data } = useQuery({
+    queryKey: ['admin-status-summary'],
+    queryFn: () => adminApi.getStatusSummary(),
+    refetchInterval: 30_000,
+    enabled: isAdmin,
+  });
+
+  const up = useCountUp(data?.up ?? 0);
+  const total = useCountUp(data?.total ?? 0);
+
+  if (!isAdmin) return null;
+
+  const allUp = data && data.up === data.total;
+  const majorityDown = data && data.total > 0 && data.up < data.total / 2;
+  const color = allUp ? 'success' : majorityDown ? 'error' : 'warning';
+
+  return (
+    <Card
+      sx={{ cursor: 'pointer', '&:hover': { boxShadow: 4 } }}
+      onClick={() => navigate('/admin')}
+    >
+      <CardContent>
+        <Box sx={{ display: 'flex', alignItems: 'center', gap: 1, mb: 1 }}>
+          <MonitorHeartOutlined color={color} />
+          <Typography variant="h6" component="div">
+            Service Status
+          </Typography>
+        </Box>
+
+        <Box sx={{ display: 'flex', alignItems: 'baseline', gap: 0.5, mb: 1 }}>
+          <Typography variant="h3" component="span" sx={{ fontWeight: 700 }}>
+            {up}
+          </Typography>
+          <Typography variant="h5" component="span" color="text.secondary">
+            / {total}
+          </Typography>
+          <Typography variant="body2" color="text.secondary" sx={{ ml: 0.5 }}>
+            Services online
+          </Typography>
+        </Box>
+
+        <Chip
+          label={allUp ? 'Alle aktiv' : majorityDown ? 'Kritisch' : 'Teilweise gestört'}
+          color={color}
+          size="small"
+          variant="outlined"
+        />
+      </CardContent>
+    </Card>
+  );
+}
+
+export default AdminStatusWidget;
--- a/frontend/src/components/dashboard/DashboardLayout.tsx
+++ b/frontend/src/components/dashboard/DashboardLayout.tsx
@@ -4,14 +4,17 @@ import Header from '../shared/Header';
 import Sidebar from '../shared/Sidebar';
 import { useAuth } from '../../contexts/AuthContext';
 import Loading from '../shared/Loading';
+import { LayoutProvider, useLayout, DRAWER_WIDTH, DRAWER_WIDTH_COLLAPSED } from '../../contexts/LayoutContext';
+import ChatPanel from '../chat/ChatPanel';

 interface DashboardLayoutProps {
  children: ReactNode;
 }

-function DashboardLayout({ children }: DashboardLayoutProps) {
+function DashboardLayoutInner({ children }: DashboardLayoutProps) {
  const [mobileOpen, setMobileOpen] = useState(false);
  const { isLoading } = useAuth();
+  const { sidebarCollapsed, chatPanelOpen } = useLayout();

  const handleDrawerToggle = () => {
    setMobileOpen(!mobileOpen);
@@ -21,6 +24,9 @@ function DashboardLayout({ children }: DashboardLayoutProps) {
    return <Loading message="Lade Dashboard..." />;
  }

+  const sidebarWidth = sidebarCollapsed ? DRAWER_WIDTH_COLLAPSED : DRAWER_WIDTH;
+  const chatWidth = chatPanelOpen ? 360 : 60;
+
  return (
    <Box sx={{ display: 'flex' }}>
      <Header onMenuClick={handleDrawerToggle} />
@@ -31,16 +37,27 @@ function DashboardLayout({ children }: DashboardLayoutProps) {
        sx={{
          flexGrow: 1,
          p: 3,
-          width: { sm: `calc(100% - 240px)` },
+          width: { sm: `calc(100% - ${sidebarWidth}px - ${chatWidth}px)` },
          minHeight: '100vh',
          backgroundColor: 'background.default',
+          transition: 'width 225ms cubic-bezier(0.4, 0, 0.6, 1)',
        }}
      >
        <Toolbar />
        {children}
      </Box>
+
+      <ChatPanel />
    </Box>
  );
 }

+function DashboardLayout({ children }: DashboardLayoutProps) {
+  return (
+    <LayoutProvider>
+      <DashboardLayoutInner>{children}</DashboardLayoutInner>
+    </LayoutProvider>
+  );
+}
+
 export default DashboardLayout;
--- a/frontend/src/components/dashboard/index.ts
+++ b/frontend/src/components/dashboard/index.ts
@@ -9,3 +9,4 @@ export { default as BookStackSearchWidget } from './BookStackSearchWidget';
 export { default as VikunjaMyTasksWidget } from './VikunjaMyTasksWidget';
 export { default as VikunjaQuickAddWidget } from './VikunjaQuickAddWidget';
 export { default as VikunjaOverdueNotifier } from './VikunjaOverdueNotifier';
+export { default as AdminStatusWidget } from './AdminStatusWidget';
--- a/frontend/src/components/shared/Header.tsx
+++ b/frontend/src/components/shared/Header.tsx
@@ -10,6 +10,7 @@ import {
  ListItemIcon,
  Divider,
  Box,
+  Tooltip,
 } from '@mui/material';
 import {
  LocalFireDepartment,
@@ -17,10 +18,15 @@ import {
  Settings,
  Logout,
  Menu as MenuIcon,
+  Launch,
+  Chat,
 } from '@mui/icons-material';
+import { useQuery } from '@tanstack/react-query';
 import { useAuth } from '../../contexts/AuthContext';
 import { useNavigate } from 'react-router-dom';
 import NotificationBell from './NotificationBell';
+import { configApi } from '../../services/config';
+import { useLayout } from '../../contexts/LayoutContext';

 interface HeaderProps {
  onMenuClick: () => void;
@@ -29,7 +35,16 @@ interface HeaderProps {
 function Header({ onMenuClick }: HeaderProps) {
  const { user, logout } = useAuth();
  const navigate = useNavigate();
+  const { toggleChatPanel } = useLayout();
  const [anchorEl, setAnchorEl] = useState<null | HTMLElement>(null);
+  const [toolsAnchorEl, setToolsAnchorEl] = useState<null | HTMLElement>(null);
+
+  const { data: externalLinks } = useQuery({
+    queryKey: ['external-links'],
+    queryFn: () => configApi.getExternalLinks(),
+    staleTime: 10 * 60 * 1000,
+    enabled: !!user,
+  });

  const handleMenuOpen = (event: React.MouseEvent<HTMLElement>) => {
    setAnchorEl(event.currentTarget);
@@ -39,6 +54,14 @@ function Header({ onMenuClick }: HeaderProps) {
    setAnchorEl(null);
  };

+  const handleToolsOpen = (event: React.MouseEvent<HTMLElement>) => {
+    setToolsAnchorEl(event.currentTarget);
+  };
+
+  const handleToolsClose = () => {
+    setToolsAnchorEl(null);
+  };
+
  const handleProfile = () => {
    handleMenuClose();
    navigate('/profile');
@@ -54,6 +77,11 @@ function Header({ onMenuClick }: HeaderProps) {
    logout();
  };

+  const handleOpenExternal = (url: string) => {
+    handleToolsClose();
+    window.open(url, '_blank', 'noopener,noreferrer');
+  };
+
  // Get initials for avatar
  const getInitials = () => {
    if (!user) return '?';
@@ -61,6 +89,16 @@ function Header({ onMenuClick }: HeaderProps) {
    return initials || user.name?.[0] || '?';
  };

+  const linkEntries = externalLinks
+    ? Object.entries(externalLinks).filter(([, url]) => !!url)
+    : [];
+
+  const linkLabels: Record<string, string> = {
+    nextcloud: 'Nextcloud',
+    bookstack: 'BookStack',
+    vikunja: 'Vikunja',
+  };
+
  return (
    <AppBar
      position="fixed"
@@ -71,7 +109,7 @@ function Header({ onMenuClick }: HeaderProps) {
      <Toolbar>
        <IconButton
          color="inherit"
-          aria-label="Menï¿½ ï¿½ffnen"
+          aria-label="Menü öffnen"
          edge="start"
          onClick={onMenuClick}
          sx={{ mr: 2, display: { sm: 'none' } }}
@@ -86,6 +124,63 @@ function Header({ onMenuClick }: HeaderProps) {

        {user && (
          <>
+            {linkEntries.length > 0 && (
+              <>
+                <Tooltip title="Externe Tools">
+                  <IconButton
+                    color="inherit"
+                    onClick={handleToolsOpen}
+                    size="small"
+                    aria-label="Externe Tools"
+                    aria-controls="tools-menu"
+                    aria-haspopup="true"
+                  >
+                    <Launch />
+                  </IconButton>
+                </Tooltip>
+
+                <Menu
+                  id="tools-menu"
+                  anchorEl={toolsAnchorEl}
+                  open={Boolean(toolsAnchorEl)}
+                  onClose={handleToolsClose}
+                  anchorOrigin={{
+                    vertical: 'bottom',
+                    horizontal: 'right',
+                  }}
+                  transformOrigin={{
+                    vertical: 'top',
+                    horizontal: 'right',
+                  }}
+                  PaperProps={{
+                    elevation: 3,
+                    sx: { minWidth: 180, mt: 1 },
+                  }}
+                >
+                  {linkEntries.map(([key, url]) => (
+                    <MenuItem key={key} onClick={() => handleOpenExternal(url)}>
+                      <ListItemIcon>
+                        <Launch fontSize="small" />
+                      </ListItemIcon>
+                      {linkLabels[key] || key}
+                    </MenuItem>
+                  ))}
+                </Menu>
+              </>
+            )}
+
+            <Tooltip title="Chat">
+              <IconButton
+                color="inherit"
+                onClick={toggleChatPanel}
+                size="small"
+                aria-label="Chat öffnen"
+                sx={{ ml: 0.5 }}
+              >
+                <Chat />
+              </IconButton>
+            </Tooltip>
+
            <NotificationBell />

            <IconButton
--- a/frontend/src/components/shared/Sidebar.tsx
+++ b/frontend/src/components/shared/Sidebar.tsx
@@ -1,5 +1,8 @@
+import { useMemo } from 'react';
 import {
+  Box,
  Drawer,
+  IconButton,
  List,
  ListItem,
  ListItemButton,
@@ -15,10 +18,16 @@ import {
  People,
  Air,
  CalendarMonth,
+  MenuBook,
+  AdminPanelSettings,
+  ChevronLeft,
+  ChevronRight,
 } from '@mui/icons-material';
 import { useNavigate, useLocation } from 'react-router-dom';
+import { useLayout, DRAWER_WIDTH, DRAWER_WIDTH_COLLAPSED } from '../../contexts/LayoutContext';
+import { useAuth } from '../../contexts/AuthContext';

-const DRAWER_WIDTH = 240;
+export { DRAWER_WIDTH, DRAWER_WIDTH_COLLAPSED };

 interface NavigationItem {
  text: string;
@@ -26,7 +35,7 @@ interface NavigationItem {
  path: string;
 }

-const navigationItems: NavigationItem[] = [
+const baseNavigationItems: NavigationItem[] = [
  {
    text: 'Dashboard',
    icon: <DashboardIcon />,
@@ -57,8 +66,19 @@ const navigationItems: NavigationItem[] = [
    icon: <Air />,
    path: '/atemschutz',
  },
+  {
+    text: 'Wissen',
+    icon: <MenuBook />,
+    path: '/wissen',
+  },
 ];

+const adminItem: NavigationItem = {
+  text: 'Admin',
+  icon: <AdminPanelSettings />,
+  path: '/admin',
+};
+
 interface SidebarProps {
  mobileOpen: boolean;
  onMobileClose: () => void;
@@ -67,6 +87,14 @@ interface SidebarProps {
 function Sidebar({ mobileOpen, onMobileClose }: SidebarProps) {
  const navigate = useNavigate();
  const location = useLocation();
+  const { sidebarCollapsed, toggleSidebar } = useLayout();
+  const { user } = useAuth();
+
+  const isAdmin = user?.groups?.includes('dashboard_admin') ?? false;
+
+  const navigationItems = useMemo(() => {
+    return isAdmin ? [...baseNavigationItems, adminItem] : baseNavigationItems;
+  }, [isAdmin]);

  const handleNavigation = (path: string) => {
    navigate(path);
@@ -74,19 +102,25 @@ function Sidebar({ mobileOpen, onMobileClose }: SidebarProps) {
  };

  const drawerContent = (
-    <>
+    <Box sx={{ display: 'flex', flexDirection: 'column', height: '100%' }}>
      <Toolbar />
-      <List>
+      <List sx={{ flex: 1 }}>
        {navigationItems.map((item) => {
          const isActive = location.pathname === item.path;
          return (
            <ListItem key={item.text} disablePadding>
-              <Tooltip title={item.text} placement="right" arrow>
+              <Tooltip
+                title={item.text}
+                placement="right"
+                arrow
+                disableHoverListener={!sidebarCollapsed}
+              >
                <ListItemButton
                  selected={isActive}
                  onClick={() => handleNavigation(item.path)}
                  aria-label={`Zu ${item.text} navigieren`}
                  sx={{
+                    justifyContent: sidebarCollapsed ? 'center' : 'initial',
                    '&.Mui-selected': {
                      backgroundColor: 'primary.light',
                      color: 'primary.contrastText',
@@ -102,18 +136,30 @@ function Sidebar({ mobileOpen, onMobileClose }: SidebarProps) {
                  <ListItemIcon
                    sx={{
                      color: isActive ? 'inherit' : 'text.secondary',
+                      minWidth: sidebarCollapsed ? 0 : undefined,
+                      justifyContent: 'center',
                    }}
                  >
                    {item.icon}
                  </ListItemIcon>
-                  <ListItemText primary={item.text} />
+                  <ListItemText
+                    primary={item.text}
+                    sx={{
+                      display: sidebarCollapsed ? 'none' : 'block',
+                    }}
+                  />
                </ListItemButton>
              </Tooltip>
            </ListItem>
          );
        })}
      </List>
-    </>
+      <Box sx={{ display: 'flex', justifyContent: 'center', mb: 1 }}>
+        <IconButton onClick={toggleSidebar} aria-label="Sidebar umschalten">
+          {sidebarCollapsed ? <ChevronRight /> : <ChevronLeft />}
+        </IconButton>
+      </Box>
+    </Box>
  );

  return (
@@ -143,11 +189,13 @@ function Sidebar({ mobileOpen, onMobileClose }: SidebarProps) {
        variant="permanent"
        sx={{
          display: { xs: 'none', sm: 'block' },
-          width: DRAWER_WIDTH,
+          width: sidebarCollapsed ? DRAWER_WIDTH_COLLAPSED : DRAWER_WIDTH,
          flexShrink: 0,
          '& .MuiDrawer-paper': {
-            width: DRAWER_WIDTH,
+            width: sidebarCollapsed ? DRAWER_WIDTH_COLLAPSED : DRAWER_WIDTH,
            boxSizing: 'border-box',
+            transition: 'width 225ms cubic-bezier(0.4, 0, 0.6, 1)',
+            overflowX: 'hidden',
          },
        }}
        open
--- a/frontend/src/contexts/ChatContext.tsx
+++ b/frontend/src/contexts/ChatContext.tsx
@@ -0,0 +1,57 @@
+import React, { createContext, useContext, useState, useCallback, ReactNode } from 'react';
+import { useQuery } from '@tanstack/react-query';
+import { nextcloudApi } from '../services/nextcloud';
+import { useLayout } from './LayoutContext';
+import type { NextcloudConversation } from '../types/nextcloud.types';
+
+interface ChatContextType {
+  rooms: NextcloudConversation[];
+  selectedRoomToken: string | null;
+  selectRoom: (token: string | null) => void;
+  connected: boolean;
+  loginName: string | null;
+}
+
+const ChatContext = createContext<ChatContextType | undefined>(undefined);
+
+interface ChatProviderProps {
+  children: ReactNode;
+}
+
+export const ChatProvider: React.FC<ChatProviderProps> = ({ children }) => {
+  const [selectedRoomToken, setSelectedRoomToken] = useState<string | null>(null);
+  const { chatPanelOpen } = useLayout();
+
+  const { data } = useQuery({
+    queryKey: ['nextcloud', 'rooms'],
+    queryFn: () => nextcloudApi.getRooms(),
+    refetchInterval: chatPanelOpen ? 30000 : false,
+    enabled: chatPanelOpen,
+  });
+
+  const rooms = data?.rooms ?? [];
+  const connected = data?.connected ?? false;
+  const loginName = data?.loginName ?? null;
+
+  const selectRoom = useCallback((token: string | null) => {
+    setSelectedRoomToken(token);
+  }, []);
+
+  const value: ChatContextType = {
+    rooms,
+    selectedRoomToken,
+    selectRoom,
+    connected,
+    loginName,
+  };
+
+  return <ChatContext.Provider value={value}>{children}</ChatContext.Provider>;
+};
+
+export const useChat = (): ChatContextType => {
+  const context = useContext(ChatContext);
+  if (context === undefined) {
+    throw new Error('useChat must be used within a ChatProvider');
+  }
+  return context;
+};
--- a/frontend/src/contexts/LayoutContext.tsx
+++ b/frontend/src/contexts/LayoutContext.tsx
@@ -0,0 +1,70 @@
+import React, { createContext, useContext, useState, useCallback, ReactNode } from 'react';
+
+export const DRAWER_WIDTH = 240;
+export const DRAWER_WIDTH_COLLAPSED = 64;
+
+interface LayoutContextType {
+  sidebarCollapsed: boolean;
+  chatPanelOpen: boolean;
+  toggleSidebar: () => void;
+  toggleChatPanel: () => void;
+  setChatPanelOpen: (open: boolean) => void;
+}
+
+const LayoutContext = createContext<LayoutContextType | undefined>(undefined);
+
+function getInitialCollapsed(): boolean {
+  try {
+    const stored = localStorage.getItem('sidebar-collapsed');
+    return stored === 'true';
+  } catch {
+    return false;
+  }
+}
+
+interface LayoutProviderProps {
+  children: ReactNode;
+}
+
+export const LayoutProvider: React.FC<LayoutProviderProps> = ({ children }) => {
+  const [sidebarCollapsed, setSidebarCollapsed] = useState(getInitialCollapsed);
+  const [chatPanelOpen, setChatPanelOpenState] = useState(false);
+
+  const toggleSidebar = useCallback(() => {
+    setSidebarCollapsed((prev) => {
+      const next = !prev;
+      try {
+        localStorage.setItem('sidebar-collapsed', String(next));
+      } catch {
+        // ignore storage errors
+      }
+      return next;
+    });
+  }, []);
+
+  const toggleChatPanel = useCallback(() => {
+    setChatPanelOpenState((prev) => !prev);
+  }, []);
+
+  const setChatPanelOpen = useCallback((open: boolean) => {
+    setChatPanelOpenState(open);
+  }, []);
+
+  const value: LayoutContextType = {
+    sidebarCollapsed,
+    chatPanelOpen,
+    toggleSidebar,
+    toggleChatPanel,
+    setChatPanelOpen,
+  };
+
+  return <LayoutContext.Provider value={value}>{children}</LayoutContext.Provider>;
+};
+
+export const useLayout = (): LayoutContextType => {
+  const context = useContext(LayoutContext);
+  if (context === undefined) {
+    throw new Error('useLayout must be used within a LayoutProvider');
+  }
+  return context;
+};
--- a/frontend/src/dompurify.d.ts
+++ b/frontend/src/dompurify.d.ts
@@ -0,0 +1,7 @@
+declare module 'dompurify' {
+  interface DOMPurifyI {
+    sanitize(source: string | Node, config?: Record<string, unknown>): string;
+  }
+  const DOMPurify: DOMPurifyI;
+  export default DOMPurify;
+}
--- a/frontend/src/hooks/useCountUp.ts
+++ b/frontend/src/hooks/useCountUp.ts
@@ -0,0 +1,42 @@
+import { useState, useEffect, useRef } from 'react';
+
+export function useCountUp(target: number, duration: number = 1000): number {
+  const [current, setCurrent] = useState(0);
+  const rafRef = useRef<number>(0);
+  const currentRef = useRef<number>(0);
+
+  useEffect(() => {
+    if (target === 0) {
+      setCurrent(0);
+      currentRef.current = 0;
+      return;
+    }
+
+    const startTime = performance.now();
+    const startValue = currentRef.current;
+
+    const animate = (now: number) => {
+      const elapsed = now - startTime;
+      const t = Math.min(elapsed / duration, 1);
+      // ease-out cubic: 1 - (1-t)^3
+      const eased = 1 - Math.pow(1 - t, 3);
+      const value = Math.round(startValue + (target - startValue) * eased);
+      setCurrent(value);
+      currentRef.current = value;
+
+      if (t < 1) {
+        rafRef.current = requestAnimationFrame(animate);
+      }
+    };
+
+    rafRef.current = requestAnimationFrame(animate);
+
+    return () => {
+      if (rafRef.current) {
+        cancelAnimationFrame(rafRef.current);
+      }
+    };
+  }, [target, duration]);
+
+  return current;
+}
--- a/frontend/src/pages/AdminDashboard.tsx
+++ b/frontend/src/pages/AdminDashboard.tsx
@@ -0,0 +1,61 @@
+import { useState } from 'react';
+import { Box, Tabs, Tab, Typography } from '@mui/material';
+import { Navigate } from 'react-router-dom';
+import DashboardLayout from '../components/dashboard/DashboardLayout';
+import ServiceManagerTab from '../components/admin/ServiceManagerTab';
+import SystemHealthTab from '../components/admin/SystemHealthTab';
+import UserOverviewTab from '../components/admin/UserOverviewTab';
+import NotificationBroadcastTab from '../components/admin/NotificationBroadcastTab';
+import { useAuth } from '../contexts/AuthContext';
+
+interface TabPanelProps {
+  children: React.ReactNode;
+  index: number;
+  value: number;
+}
+
+function TabPanel({ children, value, index }: TabPanelProps) {
+  if (value !== index) return null;
+  return <Box sx={{ pt: 3 }}>{children}</Box>;
+}
+
+function AdminDashboard() {
+  const [tab, setTab] = useState(0);
+  const { user } = useAuth();
+
+  const isAdmin = user?.groups?.includes('dashboard_admin') ?? false;
+
+  if (!isAdmin) {
+    return <Navigate to="/dashboard" replace />;
+  }
+
+  return (
+    <DashboardLayout>
+      <Typography variant="h4" sx={{ mb: 3 }}>Administration</Typography>
+
+      <Box sx={{ borderBottom: 1, borderColor: 'divider' }}>
+        <Tabs value={tab} onChange={(_e, v) => setTab(v)}>
+          <Tab label="Services" />
+          <Tab label="System" />
+          <Tab label="Benutzer" />
+          <Tab label="Broadcast" />
+        </Tabs>
+      </Box>
+
+      <TabPanel value={tab} index={0}>
+        <ServiceManagerTab />
+      </TabPanel>
+      <TabPanel value={tab} index={1}>
+        <SystemHealthTab />
+      </TabPanel>
+      <TabPanel value={tab} index={2}>
+        <UserOverviewTab />
+      </TabPanel>
+      <TabPanel value={tab} index={3}>
+        <NotificationBroadcastTab />
+      </TabPanel>
+    </DashboardLayout>
+  );
+}
+
+export default AdminDashboard;
--- a/frontend/src/pages/Dashboard.tsx
+++ b/frontend/src/pages/Dashboard.tsx
@@ -18,8 +18,10 @@ import BookStackSearchWidget from '../components/dashboard/BookStackSearchWidget
 import VikunjaMyTasksWidget from '../components/dashboard/VikunjaMyTasksWidget';
 import VikunjaQuickAddWidget from '../components/dashboard/VikunjaQuickAddWidget';
 import VikunjaOverdueNotifier from '../components/dashboard/VikunjaOverdueNotifier';
+import AdminStatusWidget from '../components/dashboard/AdminStatusWidget';
 function Dashboard() {
  const { user } = useAuth();
+  const isAdmin = user?.groups?.includes('dashboard_admin') ?? false;
  const canViewAtemschutz = user?.groups?.some(g =>
    ['dashboard_admin', 'dashboard_kommando', 'dashboard_atemschutz', 'dashboard_moderator'].includes(g)
  ) ?? false;
@@ -148,6 +150,17 @@ function Dashboard() {

          {/* Vikunja — Overdue Notifier (invisible, polling component) */}
          <VikunjaOverdueNotifier />
+
+          {/* Admin Status Widget — only for admins */}
+          {isAdmin && (
+          <Box>
+            <Fade in={!dataLoading} timeout={600} style={{ transitionDelay: '680ms' }}>
+              <Box>
+                <AdminStatusWidget />
+              </Box>
+            </Fade>
+          </Box>
+          )}
        </Box>
      </Container>
    </DashboardLayout>
--- a/frontend/src/pages/Wissen.tsx
+++ b/frontend/src/pages/Wissen.tsx
@@ -0,0 +1,240 @@
+import { useState, useEffect, useRef, useCallback } from 'react';
+import {
+  Box,
+  TextField,
+  Typography,
+  Paper,
+  List,
+  ListItem,
+  ListItemButton,
+  ListItemText,
+  CircularProgress,
+  InputAdornment,
+  Divider,
+} from '@mui/material';
+import { Search as SearchIcon } from '@mui/icons-material';
+import { useQuery } from '@tanstack/react-query';
+import DOMPurify from 'dompurify';
+import DashboardLayout from '../components/dashboard/DashboardLayout';
+import { bookstackApi } from '../services/bookstack';
+import type { BookStackPage, BookStackSearchResult } from '../types/bookstack.types';
+
+export default function Wissen() {
+  const [searchTerm, setSearchTerm] = useState('');
+  const [debouncedSearch, setDebouncedSearch] = useState('');
+  const [selectedPageId, setSelectedPageId] = useState<number | null>(null);
+  const debounceRef = useRef<ReturnType<typeof setTimeout> | null>(null);
+
+  useEffect(() => {
+    if (debounceRef.current) clearTimeout(debounceRef.current);
+    debounceRef.current = setTimeout(() => {
+      setDebouncedSearch(searchTerm.trim());
+    }, 400);
+    return () => {
+      if (debounceRef.current) clearTimeout(debounceRef.current);
+    };
+  }, [searchTerm]);
+
+  const recentQuery = useQuery({
+    queryKey: ['bookstack', 'recent'],
+    queryFn: () => bookstackApi.getRecent(),
+  });
+
+  const searchQuery = useQuery({
+    queryKey: ['bookstack', 'search', debouncedSearch],
+    queryFn: () => bookstackApi.search(debouncedSearch),
+    enabled: debouncedSearch.length > 0,
+  });
+
+  const pageQuery = useQuery({
+    queryKey: ['bookstack', 'page', selectedPageId],
+    queryFn: () => bookstackApi.getPage(selectedPageId!),
+    enabled: selectedPageId !== null,
+  });
+
+  const handleSelectPage = useCallback((id: number) => {
+    setSelectedPageId(id);
+  }, []);
+
+  const isNotConfigured =
+    recentQuery.data && !recentQuery.data.configured;
+
+  if (isNotConfigured) {
+    return (
+      <DashboardLayout>
+        <Box sx={{ p: 3 }}>
+          <Typography variant="h5" gutterBottom>
+            Wissen
+          </Typography>
+          <Typography color="text.secondary">
+            BookStack ist nicht konfiguriert. Bitte BOOKSTACK_URL, BOOKSTACK_TOKEN_ID und
+            BOOKSTACK_TOKEN_SECRET in der .env-Datei setzen.
+          </Typography>
+        </Box>
+      </DashboardLayout>
+    );
+  }
+
+  const isSearching = debouncedSearch.length > 0;
+  const listItems: (BookStackSearchResult | BookStackPage)[] = isSearching
+    ? searchQuery.data?.data ?? []
+    : recentQuery.data?.data ?? [];
+  const listLoading = isSearching ? searchQuery.isLoading : recentQuery.isLoading;
+
+  return (
+    <DashboardLayout>
+      <Box sx={{ display: 'flex', height: 'calc(100vh - 120px)', gap: 2, p: 2 }}>
+        {/* Left panel: search + list */}
+        <Paper sx={{ width: '40%', display: 'flex', flexDirection: 'column', overflow: 'hidden' }}>
+          <Box sx={{ p: 2 }}>
+            <TextField
+              fullWidth
+              size="small"
+              placeholder="Seiten durchsuchen..."
+              value={searchTerm}
+              onChange={(e) => setSearchTerm(e.target.value)}
+              InputProps={{
+                startAdornment: (
+                  <InputAdornment position="start">
+                    <SearchIcon />
+                  </InputAdornment>
+                ),
+              }}
+            />
+          </Box>
+          <Divider />
+          <Box sx={{ flex: 1, overflow: 'auto' }}>
+            {listLoading ? (
+              <Box sx={{ display: 'flex', justifyContent: 'center', py: 4 }}>
+                <CircularProgress size={28} />
+              </Box>
+            ) : listItems.length === 0 ? (
+              <Typography sx={{ p: 2 }} color="text.secondary">
+                {isSearching ? 'Keine Ergebnisse gefunden.' : 'Keine Seiten vorhanden.'}
+              </Typography>
+            ) : (
+              <List disablePadding>
+                {listItems.map((item) => (
+                  <ListItem key={item.id} disablePadding>
+                    <ListItemButton
+                      selected={selectedPageId === item.id}
+                      onClick={() => handleSelectPage(item.id)}
+                    >
+                      <ListItemText
+                        primary={item.name}
+                        secondary={
+                          'book' in item && item.book
+                            ? item.book.name
+                            : undefined
+                        }
+                        primaryTypographyProps={{ noWrap: true }}
+                        secondaryTypographyProps={{ noWrap: true }}
+                      />
+                    </ListItemButton>
+                  </ListItem>
+                ))}
+              </List>
+            )}
+          </Box>
+        </Paper>
+
+        {/* Right panel: page content */}
+        <Paper sx={{ width: '60%', overflow: 'auto', p: 3 }}>
+          {!selectedPageId ? (
+            <Typography color="text.secondary">
+              Seite aus der Liste auswaehlen, um den Inhalt anzuzeigen.
+            </Typography>
+          ) : pageQuery.isLoading ? (
+            <Box sx={{ display: 'flex', justifyContent: 'center', py: 4 }}>
+              <CircularProgress />
+            </Box>
+          ) : pageQuery.isError ? (
+            <Typography color="error">
+              Fehler beim Laden der Seite.
+            </Typography>
+          ) : pageQuery.data?.data ? (
+            <Box>
+              <Typography variant="h5" gutterBottom>
+                {pageQuery.data.data.name}
+              </Typography>
+              {pageQuery.data.data.book && (
+                <Typography variant="body2" color="text.secondary" gutterBottom>
+                  Buch: {pageQuery.data.data.book.name}
+                </Typography>
+              )}
+              <Divider sx={{ my: 2 }} />
+              <Box
+                className="bookstack-content"
+                sx={(theme) => ({
+                  '& h1, & h2, & h3, & h4, & h5, & h6': {
+                    color: theme.palette.text.primary,
+                    mt: 2,
+                    mb: 1,
+                  },
+                  '& p': {
+                    color: theme.palette.text.primary,
+                    lineHeight: 1.7,
+                    mb: 1,
+                  },
+                  '& a': {
+                    color: theme.palette.primary.main,
+                    textDecoration: 'none',
+                    '&:hover': { textDecoration: 'underline' },
+                  },
+                  '& table': {
+                    borderCollapse: 'collapse',
+                    width: '100%',
+                    mb: 2,
+                  },
+                  '& th, & td': {
+                    border: `1px solid ${theme.palette.divider}`,
+                    padding: theme.spacing(1),
+                    textAlign: 'left',
+                  },
+                  '& th': {
+                    backgroundColor: theme.palette.action.hover,
+                    fontWeight: 600,
+                  },
+                  '& img': {
+                    maxWidth: '100%',
+                    height: 'auto',
+                    borderRadius: 1,
+                  },
+                  '& code': {
+                    backgroundColor: theme.palette.action.hover,
+                    padding: '2px 6px',
+                    borderRadius: 1,
+                    fontSize: '0.875em',
+                  },
+                  '& pre': {
+                    backgroundColor: theme.palette.action.hover,
+                    padding: theme.spacing(2),
+                    borderRadius: 1,
+                    overflow: 'auto',
+                  },
+                  '& ul, & ol': {
+                    pl: 3,
+                    mb: 1,
+                  },
+                  '& blockquote': {
+                    borderLeft: `4px solid ${theme.palette.primary.main}`,
+                    pl: 2,
+                    ml: 0,
+                    color: theme.palette.text.secondary,
+                  },
+                })}
+                dangerouslySetInnerHTML={{
+                  __html: DOMPurify.sanitize(pageQuery.data.data.html),
+                }}
+              />
+            </Box>
+          ) : (
+            <Typography color="text.secondary">
+              Seite nicht gefunden.
+            </Typography>
+          )}
+        </Paper>
+      </Box>
+    </DashboardLayout>
+  );
+}
--- a/frontend/src/services/admin.ts
+++ b/frontend/src/services/admin.ts
@@ -0,0 +1,19 @@
+import { api } from './api';
+import type { MonitoredService, PingResult, StatusSummary, SystemHealth, UserOverview, BroadcastPayload } from '../types/admin.types';
+
+interface ApiResponse<T> {
+  success: boolean;
+  data: T;
+}
+
+export const adminApi = {
+  getServices: () => api.get<ApiResponse<MonitoredService[]>>('/api/admin/services').then(r => r.data.data),
+  createService: (data: { name: string; url: string }) => api.post<ApiResponse<MonitoredService>>('/api/admin/services', data).then(r => r.data.data),
+  updateService: (id: string, data: Partial<MonitoredService>) => api.put<ApiResponse<MonitoredService>>(`/api/admin/services/${id}`, data).then(r => r.data.data),
+  deleteService: (id: string) => api.delete(`/api/admin/services/${id}`).then(() => undefined),
+  pingAll: () => api.get<ApiResponse<PingResult[]>>('/api/admin/services/ping').then(r => r.data.data),
+  getStatusSummary: () => api.get<ApiResponse<StatusSummary>>('/api/admin/services/status-summary').then(r => r.data.data),
+  getSystemHealth: () => api.get<ApiResponse<SystemHealth>>('/api/admin/system/health').then(r => r.data.data),
+  getUsers: () => api.get<ApiResponse<UserOverview[]>>('/api/admin/users').then(r => r.data.data),
+  broadcast: (data: BroadcastPayload) => api.post<ApiResponse<{ sent: number }>>('/api/admin/notifications/broadcast', data).then(r => r.data.data),
+};
--- a/frontend/src/services/bookstack.ts
+++ b/frontend/src/services/bookstack.ts
@@ -1,5 +1,5 @@
 import { api } from './api';
-import type { BookStackRecentResponse, BookStackSearchResponse } from '../types/bookstack.types';
+import type { BookStackRecentResponse, BookStackSearchResponse, BookStackPageDetail } from '../types/bookstack.types';

 interface ApiResponse<T> {
  success: boolean;
@@ -14,6 +14,12 @@ export const bookstackApi = {
      .then((r) => ({ configured: r.data.configured, data: r.data.data }));
  },

+  getPage(id: number): Promise<{ configured: boolean; data: BookStackPageDetail | null }> {
+    return api
+      .get<ApiResponse<BookStackPageDetail | null>>(`/api/bookstack/pages/${id}`)
+      .then((r) => ({ configured: r.data.configured, data: r.data.data }));
+  },
+
  search(query: string): Promise<BookStackSearchResponse> {
    return api
      .get<ApiResponse<BookStackSearchResponse['data']>>('/api/bookstack/search', {
--- a/frontend/src/services/config.ts
+++ b/frontend/src/services/config.ts
@@ -0,0 +1,15 @@
+import { api } from './api';
+import type { ExternalLinks } from '../types/config.types';
+
+interface ApiResponse<T> {
+  success: boolean;
+  data: T;
+}
+
+export const configApi = {
+  getExternalLinks(): Promise<ExternalLinks> {
+    return api
+      .get<ApiResponse<ExternalLinks>>('/api/config/external-links')
+      .then((r) => r.data.data);
+  },
+};
--- a/frontend/src/services/nextcloud.ts
+++ b/frontend/src/services/nextcloud.ts
@@ -1,5 +1,5 @@
 import { api } from './api';
-import type { NextcloudTalkData, NextcloudConnectData, NextcloudPollData } from '../types/nextcloud.types';
+import type { NextcloudTalkData, NextcloudConnectData, NextcloudPollData, NextcloudMessage, NextcloudRoomListData } from '../types/nextcloud.types';

 interface ApiResponse<T> {
  success: boolean;
@@ -30,4 +30,28 @@ export const nextcloudApi = {
      .delete('/api/nextcloud/talk/connect')
      .then(() => undefined);
  },
+
+  getRooms(): Promise<NextcloudRoomListData> {
+    return api
+      .get<ApiResponse<NextcloudRoomListData>>('/api/nextcloud/talk/rooms')
+      .then((r) => r.data.data);
+  },
+
+  getMessages(token: string): Promise<NextcloudMessage[]> {
+    return api
+      .get<ApiResponse<NextcloudMessage[]>>(`/api/nextcloud/talk/rooms/${encodeURIComponent(token)}/messages`)
+      .then((r) => r.data.data);
+  },
+
+  sendMessage(token: string, message: string): Promise<void> {
+    return api
+      .post(`/api/nextcloud/talk/rooms/${encodeURIComponent(token)}/messages`, { message })
+      .then(() => undefined);
+  },
+
+  markAsRead(token: string): Promise<void> {
+    return api
+      .post(`/api/nextcloud/talk/rooms/${encodeURIComponent(token)}/read`)
+      .then(() => undefined);
+  },
 };
--- a/frontend/src/types/admin.types.ts
+++ b/frontend/src/types/admin.types.ts
@@ -0,0 +1,52 @@
+export interface MonitoredService {
+  id: string;
+  name: string;
+  url: string;
+  type: 'internal' | 'custom';
+  is_active: boolean;
+  created_at: string;
+  updated_at: string;
+}
+
+export interface PingResult {
+  name: string;
+  url: string;
+  status: 'up' | 'down';
+  latencyMs: number;
+  error?: string;
+}
+
+export interface StatusSummary {
+  up: number;
+  total: number;
+}
+
+export interface SystemHealth {
+  nodeVersion: string;
+  uptime: number;
+  memoryUsage: {
+    heapUsed: number;
+    heapTotal: number;
+    rss: number;
+    external: number;
+  };
+  dbStatus: boolean;
+  dbSize: string;
+}
+
+export interface UserOverview {
+  id: string;
+  email: string;
+  name: string;
+  role: string;
+  groups: string[];
+  is_active: boolean;
+  last_login_at: string | null;
+}
+
+export interface BroadcastPayload {
+  titel: string;
+  nachricht: string;
+  schwere?: 'info' | 'warnung' | 'fehler';
+  targetGroup?: string;
+}
--- a/frontend/src/types/bookstack.types.ts
+++ b/frontend/src/types/bookstack.types.ts
@@ -34,3 +34,24 @@ export interface BookStackSearchResponse {
  configured: boolean;
  data: BookStackSearchResult[];
 }
+
+export interface BookStackPageDetail {
+  id: number;
+  name: string;
+  slug: string;
+  book_id: number;
+  book_slug: string;
+  chapter_id: number;
+  html: string;
+  created_at: string;
+  updated_at: string;
+  url: string;
+  book?: { name: string };
+  createdBy?: { name: string };
+  updatedBy?: { name: string };
+}
+
+export interface BookStackPageDetailResponse {
+  configured: boolean;
+  data: BookStackPageDetail | null;
+}
--- a/frontend/src/types/config.types.ts
+++ b/frontend/src/types/config.types.ts
@@ -0,0 +1,5 @@
+export interface ExternalLinks {
+  nextcloud?: string;
+  bookstack?: string;
+  vikunja?: string;
+}
--- a/frontend/src/types/nextcloud.types.ts
+++ b/frontend/src/types/nextcloud.types.ts
@@ -27,3 +27,21 @@ export interface NextcloudConnectData {
 export interface NextcloudPollData {
  completed: boolean;
 }
+
+export interface NextcloudMessage {
+  id: number;
+  token: string;
+  actorType: string;
+  actorId: string;
+  actorDisplayName: string;
+  message: string;
+  timestamp: number;
+  messageType: string;
+  systemMessage: string;
+}
+
+export interface NextcloudRoomListData {
+  connected: boolean;
+  rooms: NextcloudConversation[];
+  loginName?: string;
+}