diff --git a/src/notifications/notifications.service.ts b/src/notifications/notifications.service.ts
index fa4d448c..f0634229 100644
--- a/src/notifications/notifications.service.ts
+++ b/src/notifications/notifications.service.ts
@@ -1,15 +1,21 @@
-import { Injectable, Optional } from '@nestjs/common';
+import { Injectable, Optional, NotFoundException, BadRequestException } from '@nestjs/common';
 import { InjectRepository } from '@nestjs/typeorm';
-import { Repository, MoreThan } from 'typeorm';
+import { Repository, MoreThan, In } from 'typeorm';
 import { Notification, NotificationType, NotificationStatus } from './entities/notification.entity';
 import { PaginationService } from '../common/services/pagination.service';
 import { PaginationQueryDto } from '../common/dto/pagination.dto';
+import { CreateNotificationDto } from './dto/notification.dto';
+import { SendTemplatedNotificationDto } from './dto/preferences.dto';
+import { PreferencesService } from './preferences/preferences.service';
+import { NotificationTemplateService } from './templates/notification-template.service';
 
 @Injectable()
 export class NotificationsService {
   constructor(
     @InjectRepository(Notification)
     private notificationRepository: Repository<Notification>,
+    private readonly preferencesService: PreferencesService,
+    private readonly templateService: NotificationTemplateService,
     @Optional()
     private paginationService: PaginationService = new PaginationService(),
   ) {}
@@ -46,19 +52,113 @@ export class NotificationsService {
     return this.notificationRepository.find({ where: { userId } });
   }
 
-  // Stubs for other methods (to satisfy typecheck)
-  async send(_dto: any) {
-    return null;
+  async create(dto: CreateNotificationDto) {
+    const notification = this.notificationRepository.create({
+      userId: dto.userId,
+      title: dto.title,
+      content: dto.content,
+      type: dto.type ?? NotificationType.IN_APP,
+      priority: dto.priority,
+      metadata: dto.metadata,
+      status: NotificationStatus.PENDING,
+    });
+
+    return this.notificationRepository.save(notification);
   }
-  async sendTemplated(_dto: any) {
-    return [];
+
+  async send(dto: CreateNotificationDto) {
+    const notification = await this.create(dto);
+
+    const prefs = await this.preferencesService.getPreferences(dto.userId);
+
+    if (prefs.globalUnsubscribe) {
+      return notification;
+    }
+
+    const channels: { enabled: boolean; type: NotificationType }[] = [
+      { enabled: prefs.inAppEnabled, type: NotificationType.IN_APP },
+      { enabled: prefs.emailEnabled, type: NotificationType.EMAIL },
+      { enabled: prefs.pushEnabled, type: NotificationType.PUSH },
+      { enabled: prefs.smsEnabled, type: NotificationType.SMS },
+    ];
+
+    const dispatches: Promise<Notification>[] = [];
+
+    for (const channel of channels) {
+      if (channel.enabled) {
+        const channelNotification = this.notificationRepository.create({
+          userId: dto.userId,
+          title: dto.title,
+          content: dto.content,
+          type: channel.type,
+          priority: dto.priority,
+          metadata: dto.metadata,
+          status: NotificationStatus.SENT,
+        });
+        dispatches.push(this.notificationRepository.save(channelNotification));
+      }
+    }
+
+    await Promise.all(dispatches);
+
+    return notification;
   }
-  async unsubscribe(_userId: string, _eventType: string) {
-    return;
+
+  async sendTemplated(dto: SendTemplatedNotificationDto) {
+    const prefs = await this.preferencesService.getPreferences(dto.userId);
+
+    if (prefs.globalUnsubscribe) {
+      throw new BadRequestException('User has globally unsubscribed from notifications');
+    }
+
+    if (
+      prefs.eventFrequency?.[dto.eventType] === 'never'
+    ) {
+      throw new BadRequestException(
+        `User has unsubscribed from event type "${dto.eventType}"`,
+      );
+    }
+
+    const rendered = await this.templateService.renderByName(
+      dto.templateName,
+      dto.context,
+      dto.templateVersion,
+    );
+
+    const channels: { enabled: boolean; type: NotificationType }[] = [
+      { enabled: prefs.inAppEnabled, type: NotificationType.IN_APP },
+      { enabled: prefs.emailEnabled, type: NotificationType.EMAIL },
+      { enabled: prefs.pushEnabled, type: NotificationType.PUSH },
+      { enabled: prefs.smsEnabled, type: NotificationType.SMS },
+    ];
+
+    const saved: Notification[] = [];
+
+    for (const channel of channels) {
+      if (channel.enabled) {
+        const notification = this.notificationRepository.create({
+          userId: dto.userId,
+          title: rendered.subject ?? dto.templateName,
+          content: rendered.body,
+          type: channel.type,
+          status: NotificationStatus.SENT,
+          metadata: {
+            templateName: dto.templateName,
+            templateVersion: rendered.templateVersion,
+            eventType: dto.eventType,
+          },
+        });
+        saved.push(await this.notificationRepository.save(notification));
+      }
+    }
+
+    return saved;
   }
+
   async findForUser(userId: string, query?: PaginationQueryDto) {
     const limit = query?.limit ?? 20;
-    const offset = query?.offset ?? (query?.cursor ? undefined : ((query?.page ?? 1) - 1) * limit);
+    const offset =
+      query?.offset ?? (query?.cursor ? undefined : ((query?.page ?? 1) - 1) * limit);
 
     const qb = this.notificationRepository
       .createQueryBuilder('notification')
@@ -66,13 +166,55 @@ export class NotificationsService {
 
     return this.paginationService.paginate(qb, query?.cursor, limit, offset, 'createdAt');
   }
-  async create(_dto: any) {
-    return null;
+
+  async markRead(id: string, userId: string) {
+    const notification = await this.notificationRepository.findOne({
+      where: { id },
+    });
+
+    if (!notification) {
+      throw new NotFoundException(`Notification ${id} not found`);
+    }
+
+    if (notification.userId !== userId) {
+      throw new BadRequestException('You do not own this notification');
+    }
+
+    if (notification.isRead) {
+      return notification;
+    }
+
+    notification.isRead = true;
+    notification.readAt = new Date();
+
+    return this.notificationRepository.save(notification);
   }
-  async markRead(_id: string, _userId: string) {
-    return null;
+
+  async markManyRead(ids: string[], userId: string) {
+    if (!ids.length) {
+      return;
+    }
+
+    const notifications = await this.notificationRepository.find({
+      where: { id: In(ids) },
+    });
+
+    if (notifications.length !== ids.length) {
+      throw new NotFoundException('One or more notifications not found');
+    }
+
+    const owned = notifications.filter((n) => n.userId === userId);
+    if (owned.length !== ids.length) {
+      throw new BadRequestException('You do not own one or more of these notifications');
+    }
+
+    await this.notificationRepository.update(
+      { id: In(ids), userId },
+      { isRead: true, readAt: new Date() },
+    );
   }
-  async markManyRead(_ids: string[], _userId: string) {
-    return;
+
+  async unsubscribe(userId: string, eventType: string) {
+    return this.preferencesService.unsubscribe(userId, eventType);
   }
 }
diff --git a/src/notifications/preferences/preferences.service.ts b/src/notifications/preferences/preferences.service.ts
index 4b466b3c..00da3dd6 100644
--- a/src/notifications/preferences/preferences.service.ts
+++ b/src/notifications/preferences/preferences.service.ts
@@ -57,4 +57,27 @@ export class PreferencesService {
     preferences[channel] = !preferences[channel];
     return this.preferencesRepository.save(preferences);
   }
+
+  /**
+   * Unsubscribe user from a specific event type or all notifications.
+   * If eventType is 'all', sets globalUnsubscribe to true.
+   * Otherwise, sets the event frequency to 'never' for that event type.
+   */
+  async unsubscribe(
+    userId: string,
+    eventType: string,
+  ): Promise<NotificationPreferences> {
+    const preferences = await this.getPreferences(userId);
+
+    if (eventType === 'all') {
+      preferences.globalUnsubscribe = true;
+    } else {
+      if (!preferences.eventFrequency) {
+        preferences.eventFrequency = {};
+      }
+      preferences.eventFrequency[eventType] = 'never';
+    }
+
+    return this.preferencesRepository.save(preferences);
+  }
 }