diff --git a/backend/docker-compose.yml b/backend/docker-compose.yml
index 1fc0aa2..661100c 100644
--- a/backend/docker-compose.yml
+++ b/backend/docker-compose.yml
@@ -403,6 +403,30 @@ services:
     networks:
       - genex-network
 
+  referral-service:
+    build:
+      context: .
+      dockerfile: services/referral-service/Dockerfile
+    container_name: genex-referral-service
+    ports:
+      - "4013:3013"
+    environment:
+      - NODE_ENV=development
+      - PORT=3013
+      - SERVICE_NAME=referral-service
+      - DB_HOST=postgres
+      - DB_PORT=5432
+      - DB_USERNAME=genex
+      - DB_PASSWORD=${DB_PASSWORD}
+      - DB_NAME=genex
+      - JWT_ACCESS_SECRET=dev-access-secret-change-in-production
+      - KAFKA_BROKERS=kafka:9092
+    depends_on:
+      postgres:
+        condition: service_healthy
+    networks:
+      - genex-network
+
   # ============================================================
   # Go Services (3)
   # ============================================================
diff --git a/backend/migrations/047_create_referral_profiles.sql b/backend/migrations/047_create_referral_profiles.sql
new file mode 100644
index 0000000..7f28930
--- /dev/null
+++ b/backend/migrations/047_create_referral_profiles.sql
@@ -0,0 +1,51 @@
+-- Migration 047: Create referral_profiles table
+-- 推荐关系表: 每个用户一条记录，记录推荐码、推荐人、推荐链
+
+CREATE TABLE IF NOT EXISTS referral_profiles (
+    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+
+    -- 用户 ID (对应 users.id)
+    user_id UUID NOT NULL,
+
+    -- 此用户的推荐码 (用于邀请他人注册)
+    referral_code VARCHAR(20) NOT NULL,
+
+    -- 推荐人 userId (注册时使用了他人推荐码时才有值)
+    referrer_id UUID,
+
+    -- 注册时填写的推荐码 (即推荐人的推荐码)
+    used_code VARCHAR(20),
+
+    -- 推荐链: 从直接推荐人到顶层的 userId 数组 (PostgreSQL 原生 text[])
+    referral_chain TEXT[] NOT NULL DEFAULT '{}',
+
+    -- 直推下级人数
+    direct_referral_count INTEGER NOT NULL DEFAULT 0,
+
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+-- 唯一约束
+CREATE UNIQUE INDEX IF NOT EXISTS idx_referral_profiles_user
+    ON referral_profiles(user_id);
+
+CREATE UNIQUE INDEX IF NOT EXISTS idx_referral_profiles_code
+    ON referral_profiles(referral_code);
+
+-- 推荐人查询加速
+CREATE INDEX IF NOT EXISTS idx_referral_profiles_referrer
+    ON referral_profiles(referrer_id);
+
+-- updated_at 自动更新触发器
+CREATE OR REPLACE FUNCTION update_referral_profiles_updated_at()
+RETURNS TRIGGER AS $$
+BEGIN
+    NEW.updated_at = NOW();
+    RETURN NEW;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE TRIGGER trg_referral_profiles_updated_at
+    BEFORE UPDATE ON referral_profiles
+    FOR EACH ROW EXECUTE FUNCTION update_referral_profiles_updated_at();
diff --git a/backend/services/auth-service/src/application/services/auth.service.ts b/backend/services/auth-service/src/application/services/auth.service.ts
index 960ec70..3767934 100644
--- a/backend/services/auth-service/src/application/services/auth.service.ts
+++ b/backend/services/auth-service/src/application/services/auth.service.ts
@@ -22,6 +22,7 @@ export interface RegisterDto {
   smsCode: string;
   password?: string;
   nickname?: string;
+  referralCode?: string; // 推荐人的推荐码（可选）
 }
 
 export interface LoginDto {
@@ -103,6 +104,7 @@ export class AuthService {
       phone: user.phone,
       email: user.email,
       role: user.role,
+      referralCode: dto.referralCode?.toUpperCase() ?? null,
       timestamp: new Date().toISOString(),
     });
 
diff --git a/backend/services/auth-service/src/application/services/event-publisher.service.ts b/backend/services/auth-service/src/application/services/event-publisher.service.ts
index 069bdcf..8de67f3 100644
--- a/backend/services/auth-service/src/application/services/event-publisher.service.ts
+++ b/backend/services/auth-service/src/application/services/event-publisher.service.ts
@@ -1,4 +1,5 @@
-import { Injectable } from '@nestjs/common';
+import { Injectable, Logger, OnModuleInit, OnModuleDestroy } from '@nestjs/common';
+import { Kafka, Producer } from 'kafkajs';
 import {
   UserRegisteredEvent,
   UserLoggedInEvent,
@@ -10,66 +11,75 @@ import {
 } from '../../domain/events/auth.events';
 
 /**
- * Event publisher using Outbox pattern.
- * Events are written to the outbox table within the same DB transaction,
- * then published to Kafka by the OutboxRelay or Debezium CDC.
+ * Event publisher — 直接发布到 Kafka (fire-and-forget, Kafka 不可用时静默丢弃)
+ * 生产环境可改为 Outbox pattern 保证 at-least-once 语义
  */
 @Injectable()
-export class EventPublisherService {
-  async publishUserRegistered(event: UserRegisteredEvent): Promise<void> {
-    // In Phase 1, we use direct Kafka publish.
-    // In production, this would use OutboxService.publishWithinTransaction()
-    // to ensure atomicity with the user creation.
-    await this.publishToOutbox('genex.user.registered', 'User', event.userId, 'user.registered', event);
-  }
+export class EventPublisherService implements OnModuleInit, OnModuleDestroy {
+  private readonly logger = new Logger(EventPublisherService.name);
+  private producer: Producer | null = null;
+  private connected = false;
 
-  async publishUserLoggedIn(event: UserLoggedInEvent): Promise<void> {
-    await this.publishToOutbox('genex.user.logged-in', 'User', event.userId, 'user.logged_in', event);
-  }
-
-  async publishUserLoggedOut(event: UserLoggedOutEvent): Promise<void> {
-    await this.publishToOutbox('genex.user.logged-out', 'User', event.userId, 'user.logged_out', event);
-  }
-
-  async publishPasswordChanged(event: PasswordChangedEvent): Promise<void> {
-    await this.publishToOutbox('genex.user.password-changed', 'User', event.userId, 'user.password_changed', event);
-  }
-
-  async publishAccountLocked(event: AccountLockedEvent): Promise<void> {
-    await this.publishToOutbox('genex.user.locked', 'User', event.userId, 'user.account_locked', event);
-  }
-
-  async publishPhoneChanged(event: PhoneChangedEvent): Promise<void> {
-    await this.publishToOutbox('genex.user.phone-changed', 'User', event.userId, 'user.phone_changed', event);
-  }
-
-  async publishPasswordReset(event: PasswordResetEvent): Promise<void> {
-    await this.publishToOutbox('genex.user.password-reset', 'User', event.userId, 'user.password_reset', event);
-  }
-
-  private async publishToOutbox(
-    topic: string,
-    aggregateType: string,
-    aggregateId: string,
-    eventType: string,
-    payload: any,
-  ): Promise<void> {
-    // This will be wired to OutboxService in the module setup
-    // For now, stores the event intent. The actual Kafka publish happens via OutboxRelay.
-    if (this.outboxService) {
-      await this.outboxService.publish({
-        aggregateType,
-        aggregateId,
-        eventType,
-        topic,
-        payload,
-      });
+  async onModuleInit() {
+    const brokers = (process.env.KAFKA_BROKERS || 'localhost:9092').split(',').map((b) => b.trim());
+    try {
+      const kafka = new Kafka({ clientId: 'auth-service', brokers, retry: { retries: 3 } });
+      this.producer = kafka.producer({ idempotent: false });
+      await this.producer.connect();
+      this.connected = true;
+      this.logger.log(`Kafka producer connected [${brokers.join(', ')}]`);
+    } catch (err) {
+      this.logger.warn(`Kafka 不可用，事件将被丢弃: ${err.message}`);
     }
   }
 
-  private outboxService: any;
+  async onModuleDestroy() {
+    if (this.connected && this.producer) {
+      await this.producer.disconnect();
+    }
+  }
 
-  setOutboxService(outboxService: any): void {
-    this.outboxService = outboxService;
+  async publishUserRegistered(event: UserRegisteredEvent): Promise<void> {
+    await this.publish('genex.user.registered', event.userId, 'user.registered', event);
+  }
+
+  async publishUserLoggedIn(event: UserLoggedInEvent): Promise<void> {
+    await this.publish('genex.user.logged-in', event.userId, 'user.logged_in', event);
+  }
+
+  async publishUserLoggedOut(event: UserLoggedOutEvent): Promise<void> {
+    await this.publish('genex.user.logged-out', event.userId, 'user.logged_out', event);
+  }
+
+  async publishPasswordChanged(event: PasswordChangedEvent): Promise<void> {
+    await this.publish('genex.user.password-changed', event.userId, 'user.password_changed', event);
+  }
+
+  async publishAccountLocked(event: AccountLockedEvent): Promise<void> {
+    await this.publish('genex.user.locked', event.userId, 'user.account_locked', event);
+  }
+
+  async publishPhoneChanged(event: PhoneChangedEvent): Promise<void> {
+    await this.publish('genex.user.phone-changed', event.userId, 'user.phone_changed', event);
+  }
+
+  async publishPasswordReset(event: PasswordResetEvent): Promise<void> {
+    await this.publish('genex.user.password-reset', event.userId, 'user.password_reset', event);
+  }
+
+  private async publish(topic: string, key: string, eventType: string, payload: any): Promise<void> {
+    if (!this.connected || !this.producer) return;
+    try {
+      await this.producer.send({
+        topic,
+        messages: [{
+          key,
+          value: JSON.stringify(payload),
+          headers: { eventType, timestamp: new Date().toISOString(), source: 'auth-service' },
+        }],
+      });
+    } catch (err) {
+      this.logger.warn(`事件发布失败 topic=${topic}: ${err.message}`);
+    }
   }
 }
diff --git a/backend/services/auth-service/src/domain/events/auth.events.ts b/backend/services/auth-service/src/domain/events/auth.events.ts
index 467cd86..de5006b 100644
--- a/backend/services/auth-service/src/domain/events/auth.events.ts
+++ b/backend/services/auth-service/src/domain/events/auth.events.ts
@@ -3,6 +3,7 @@ export interface UserRegisteredEvent {
   phone: string | null;
   email: string | null;
   role: string;
+  referralCode: string | null; // 注册时填写的推荐码（推荐人的码）
   timestamp: string;
 }
 
diff --git a/backend/services/auth-service/src/interface/http/dto/register.dto.ts b/backend/services/auth-service/src/interface/http/dto/register.dto.ts
index f4d3464..a4fdb2f 100644
--- a/backend/services/auth-service/src/interface/http/dto/register.dto.ts
+++ b/backend/services/auth-service/src/interface/http/dto/register.dto.ts
@@ -24,4 +24,10 @@ export class RegisterDto {
   @IsString()
   @MaxLength(50)
   nickname?: string;
+
+  @ApiPropertyOptional({ description: '推荐码（可选）', example: 'GNX1A2B3' })
+  @IsOptional()
+  @IsString()
+  @Matches(/^[A-Z0-9]{6,20}$/i, { message: '推荐码格式无效' })
+  referralCode?: string;
 }
diff --git a/backend/services/referral-service/Dockerfile b/backend/services/referral-service/Dockerfile
new file mode 100644
index 0000000..55fc6be
--- /dev/null
+++ b/backend/services/referral-service/Dockerfile
@@ -0,0 +1,23 @@
+FROM node:20-alpine AS builder
+WORKDIR /app
+
+# Install service dependencies
+COPY services/referral-service/package*.json ./services/referral-service/
+WORKDIR /app/services/referral-service
+RUN npm install
+
+# Copy service source and build
+COPY services/referral-service/ ./
+RUN npm run build
+
+FROM node:20-alpine
+WORKDIR /app
+RUN apk add --no-cache dumb-init
+COPY --from=builder /app/services/referral-service/dist ./dist
+COPY --from=builder /app/services/referral-service/node_modules ./node_modules
+COPY --from=builder /app/services/referral-service/package.json ./
+USER node
+EXPOSE 3013
+HEALTHCHECK --interval=30s --timeout=5s --start-period=20s --retries=3 \
+    CMD wget --no-verbose --tries=1 --spider http://localhost:3013/api/v1/health || exit 1
+CMD ["dumb-init", "node", "dist/main"]
diff --git a/backend/services/referral-service/nest-cli.json b/backend/services/referral-service/nest-cli.json
new file mode 100644
index 0000000..2566481
--- /dev/null
+++ b/backend/services/referral-service/nest-cli.json
@@ -0,0 +1,5 @@
+{
+  "$schema": "https://json.schemastore.org/nest-cli",
+  "collection": "@nestjs/schematics",
+  "sourceRoot": "src"
+}
diff --git a/backend/services/referral-service/package.json b/backend/services/referral-service/package.json
new file mode 100644
index 0000000..c3d2ff9
--- /dev/null
+++ b/backend/services/referral-service/package.json
@@ -0,0 +1,39 @@
+{
+  "name": "@genex/referral-service",
+  "version": "1.0.0",
+  "description": "Genex Referral Service - referral code generation, relationship tracking, chain management",
+  "scripts": {
+    "start": "nest start",
+    "start:dev": "nest start --watch",
+    "start:prod": "node dist/main",
+    "build": "nest build",
+    "test": "jest"
+  },
+  "dependencies": {
+    "@nestjs/common": "^10.3.0",
+    "@nestjs/core": "^10.3.0",
+    "@nestjs/platform-express": "^10.3.0",
+    "@nestjs/typeorm": "^10.0.1",
+    "@nestjs/jwt": "^10.2.0",
+    "@nestjs/passport": "^10.0.3",
+    "@nestjs/swagger": "^7.2.0",
+    "@nestjs/throttler": "^5.1.0",
+    "typeorm": "^0.3.19",
+    "pg": "^8.11.3",
+    "passport": "^0.7.0",
+    "passport-jwt": "^4.0.1",
+    "kafkajs": "^2.2.4",
+    "class-validator": "^0.14.0",
+    "class-transformer": "^0.5.1",
+    "reflect-metadata": "^0.2.1",
+    "rxjs": "^7.8.1"
+  },
+  "devDependencies": {
+    "@nestjs/cli": "^10.3.0",
+    "@nestjs/testing": "^10.3.0",
+    "@types/node": "^20.11.0",
+    "@types/passport-jwt": "^4.0.1",
+    "typescript": "^5.3.0",
+    "ts-node": "^10.9.0"
+  }
+}
diff --git a/backend/services/referral-service/src/app.module.ts b/backend/services/referral-service/src/app.module.ts
new file mode 100644
index 0000000..007b2db
--- /dev/null
+++ b/backend/services/referral-service/src/app.module.ts
@@ -0,0 +1,25 @@
+import { Module } from '@nestjs/common';
+import { TypeOrmModule } from '@nestjs/typeorm';
+import { ReferralModule } from './referral.module';
+
+@Module({
+  imports: [
+    TypeOrmModule.forRoot({
+      type: 'postgres',
+      host: process.env.DB_HOST || 'localhost',
+      port: parseInt(process.env.DB_PORT || '5432', 10),
+      username: process.env.DB_USERNAME || 'genex',
+      password: process.env.DB_PASSWORD || 'genex_dev_password',
+      database: process.env.DB_NAME || 'genex',
+      autoLoadEntities: true,
+      synchronize: false,
+      logging: process.env.NODE_ENV === 'development',
+      extra: {
+        max: parseInt(process.env.DB_POOL_MAX || '10', 10),
+        min: parseInt(process.env.DB_POOL_MIN || '2', 10),
+      },
+    }),
+    ReferralModule,
+  ],
+})
+export class AppModule {}
diff --git a/backend/services/referral-service/src/application/event-handlers/user-registered.handler.ts b/backend/services/referral-service/src/application/event-handlers/user-registered.handler.ts
new file mode 100644
index 0000000..bdc9972
--- /dev/null
+++ b/backend/services/referral-service/src/application/event-handlers/user-registered.handler.ts
@@ -0,0 +1,90 @@
+import { Injectable, Logger, OnModuleInit } from '@nestjs/common';
+import { Kafka, Consumer, EachMessagePayload } from 'kafkajs';
+import { ReferralService } from '../services/referral.service';
+
+interface UserRegisteredPayload {
+  userId: string;
+  phone: string | null;
+  email: string | null;
+  role: string;
+  referralCode: string | null; // 注册时填写的推荐码 (推荐人的码)
+  timestamp: string;
+}
+
+/**
+ * 监听 auth-service 发布的 genex.user.registered 事件
+ * 自动为新用户创建推荐档案
+ */
+@Injectable()
+export class UserRegisteredHandler implements OnModuleInit {
+  private readonly logger = new Logger(UserRegisteredHandler.name);
+  private consumer: Consumer;
+
+  constructor(private readonly referralService: ReferralService) {}
+
+  async onModuleInit() {
+    const brokers = (process.env.KAFKA_BROKERS || 'localhost:9092').split(',').map((b) => b.trim());
+    const kafka = new Kafka({
+      clientId: 'referral-service',
+      brokers,
+      retry: { retries: 5 },
+    });
+
+    this.consumer = kafka.consumer({ groupId: 'genex-referral-service' });
+
+    try {
+      await this.consumer.connect();
+      await this.consumer.subscribe({
+        topic: 'genex.user.registered',
+        fromBeginning: false,
+      });
+
+      await this.consumer.run({
+        eachMessage: async (payload: EachMessagePayload) => {
+          await this.handleMessage(payload);
+        },
+      });
+
+      this.logger.log('已订阅 genex.user.registered');
+    } catch (err) {
+      // Kafka 不可用时不阻断服务启动
+      this.logger.warn(`Kafka 连接失败 (将跳过事件监听): ${err.message}`);
+    }
+  }
+
+  private async handleMessage(payload: EachMessagePayload): Promise<void> {
+    const raw = payload.message.value?.toString();
+    if (!raw) return;
+
+    let event: UserRegisteredPayload;
+    try {
+      event = JSON.parse(raw);
+    } catch {
+      this.logger.error('事件消息解析失败');
+      return;
+    }
+
+    if (!event.userId) {
+      this.logger.warn('无效事件: 缺少 userId');
+      return;
+    }
+
+    try {
+      await this.referralService.createProfile({
+        userId: event.userId,
+        usedCode: event.referralCode ?? null,
+      });
+    } catch (err) {
+      this.logger.error(`创建推荐档案失败 userId=${event.userId}: ${err.message}`);
+      // 不 rethrow — 避免死锁，允许 Kafka 继续消费
+    }
+  }
+
+  async onModuleDestroy() {
+    try {
+      await this.consumer?.disconnect();
+    } catch {
+      // ignore
+    }
+  }
+}
diff --git a/backend/services/referral-service/src/application/services/referral.service.ts b/backend/services/referral-service/src/application/services/referral.service.ts
new file mode 100644
index 0000000..087dee3
--- /dev/null
+++ b/backend/services/referral-service/src/application/services/referral.service.ts
@@ -0,0 +1,166 @@
+import {
+  Injectable,
+  Logger,
+  Inject,
+  NotFoundException,
+  ConflictException,
+  BadRequestException,
+} from '@nestjs/common';
+import { ReferralProfile } from '../../domain/entities/referral-profile.entity';
+import { ReferralCode } from '../../domain/value-objects/referral-code.vo';
+import { ReferralChain } from '../../domain/value-objects/referral-chain.vo';
+import {
+  REFERRAL_PROFILE_REPOSITORY,
+  IReferralProfileRepository,
+} from '../../domain/repositories/referral-profile.repository.interface';
+
+export interface CreateReferralCommand {
+  userId: string;
+  usedCode: string | null; // 注册时填写的推荐码 (推荐人的码)
+}
+
+export interface ReferralInfo {
+  userId: string;
+  referralCode: string;
+  referrerId: string | null;
+  usedCode: string | null;
+  referralChain: string[];
+  directReferralCount: number;
+  createdAt: Date;
+}
+
+export interface DirectReferralItem {
+  userId: string;
+  referralCode: string;
+  joinedAt: Date;
+}
+
+@Injectable()
+export class ReferralService {
+  private readonly logger = new Logger(ReferralService.name);
+
+  constructor(
+    @Inject(REFERRAL_PROFILE_REPOSITORY)
+    private readonly profileRepo: IReferralProfileRepository,
+  ) {}
+
+  /**
+   * 用户注册后创建推荐档案
+   * 由 UserRegisteredHandler 在收到 Kafka 事件后调用
+   */
+  async createProfile(command: CreateReferralCommand): Promise<{ referralCode: string }> {
+    if (await this.profileRepo.existsByUserId(command.userId)) {
+      this.logger.warn(`推荐档案已存在, userId=${command.userId}`);
+      const existing = await this.profileRepo.findByUserId(command.userId);
+      return { referralCode: existing!.referralCode };
+    }
+
+    // 生成唯一推荐码
+    const referralCode = await this.generateUniqueCode();
+
+    // 查找推荐人
+    let referrerId: string | null = null;
+    let referralChain: string[] = [];
+
+    if (command.usedCode) {
+      const referrerProfile = await this.profileRepo.findByCode(command.usedCode);
+      if (!referrerProfile) {
+        // 推荐码无效，静默忽略 (不阻止注册)
+        this.logger.warn(`无效推荐码 ${command.usedCode}, userId=${command.userId}, 忽略推荐关系`);
+      } else {
+        // 防止自引用
+        if (referrerProfile.userId === command.userId) {
+          throw new BadRequestException('不能使用自己的推荐码');
+        }
+
+        // 防止循环推荐
+        const chain = ReferralChain.fromArray(referrerProfile.referralChain);
+        if (chain.contains(command.userId)) {
+          this.logger.warn(`检测到循环推荐, userId=${command.userId}`);
+        } else {
+          referrerId = referrerProfile.userId;
+          referralChain = ReferralChain.buildFromReferrer(
+            referrerProfile.userId,
+            referrerProfile.referralChain,
+          ).toArray();
+
+          // 递增推荐人的直推计数
+          referrerProfile.incrementDirectReferral();
+          await this.profileRepo.save(referrerProfile);
+        }
+      }
+    }
+
+    const profile = ReferralProfile.create({
+      userId: command.userId,
+      referralCode,
+      referrerId,
+      usedCode: command.usedCode ? command.usedCode.toUpperCase() : null,
+      referralChain,
+    });
+
+    const saved = await this.profileRepo.save(profile);
+    this.logger.log(
+      `推荐档案已创建: userId=${command.userId} code=${referralCode} referrer=${referrerId ?? 'none'}`,
+    );
+
+    return { referralCode: saved.referralCode };
+  }
+
+  /** 获取我的推荐信息 */
+  async getMyInfo(userId: string): Promise<ReferralInfo> {
+    const profile = await this.profileRepo.findByUserId(userId);
+    if (!profile) {
+      throw new NotFoundException('推荐档案不存在');
+    }
+    return this.toInfo(profile);
+  }
+
+  /** 验证推荐码是否有效 */
+  async validateCode(code: string): Promise<{ valid: boolean; referrerId?: string }> {
+    const profile = await this.profileRepo.findByCode(code);
+    if (!profile) return { valid: false };
+    return { valid: true, referrerId: profile.userId };
+  }
+
+  /** 获取直推列表 */
+  async getDirectReferrals(
+    userId: string,
+    offset = 0,
+    limit = 20,
+  ): Promise<{ items: DirectReferralItem[]; total: number }> {
+    const [profiles, total] = await this.profileRepo.findDirectReferrals(userId, offset, limit);
+    return {
+      items: profiles.map((p) => ({
+        userId: p.userId,
+        referralCode: p.referralCode,
+        joinedAt: p.createdAt,
+      })),
+      total,
+    };
+  }
+
+  /* ── Private ── */
+
+  private async generateUniqueCode(maxRetries = 10): Promise<string> {
+    for (let i = 0; i < maxRetries; i++) {
+      const code = ReferralCode.generate().value;
+      if (!(await this.profileRepo.existsByCode(code))) {
+        return code;
+      }
+    }
+    throw new Error('推荐码生成失败，请重试');
+  }
+
+  private toInfo(profile: ReferralProfile): ReferralInfo {
+    return {
+      userId: profile.userId,
+      referralCode: profile.referralCode,
+      referrerId: profile.referrerId,
+      usedCode: profile.usedCode,
+      referralChain: profile.referralChain,
+      directReferralCount: profile.directReferralCount,
+      createdAt: profile.createdAt,
+    };
+  }
+}
diff --git a/backend/services/referral-service/src/domain/entities/referral-profile.entity.ts b/backend/services/referral-service/src/domain/entities/referral-profile.entity.ts
new file mode 100644
index 0000000..3347520
--- /dev/null
+++ b/backend/services/referral-service/src/domain/entities/referral-profile.entity.ts
@@ -0,0 +1,98 @@
+import {
+  Entity,
+  PrimaryGeneratedColumn,
+  Column,
+  CreateDateColumn,
+  UpdateDateColumn,
+  Index,
+} from 'typeorm';
+import { ReferralCode } from '../value-objects/referral-code.vo';
+import { ReferralChain } from '../value-objects/referral-chain.vo';
+
+/**
+ * ReferralProfile — 推荐关系聚合根
+ *
+ * 职责:
+ * - 为每个注册用户持有唯一推荐码
+ * - 记录推荐人 (usedCode / referrerId)
+ * - 维护推荐链 (referralChain)
+ * - 统计直推数量
+ */
+@Entity('referral_profiles')
+@Index('idx_referral_profiles_code', ['referralCode'], { unique: true })
+@Index('idx_referral_profiles_user', ['userId'], { unique: true })
+@Index('idx_referral_profiles_referrer', ['referrerId'])
+export class ReferralProfile {
+  @PrimaryGeneratedColumn('uuid')
+  id: string;
+
+  /** 用户 ID (UUID, 外键指向 users 表) */
+  @Column({ name: 'user_id', type: 'uuid' })
+  userId: string;
+
+  /** 此用户的推荐码 (用于邀请他人) */
+  @Column({ name: 'referral_code', type: 'varchar', length: 20 })
+  referralCode: string;
+
+  /** 推荐人 userId (注册时填写的推荐码对应的用户) */
+  @Column({ name: 'referrer_id', type: 'uuid', nullable: true })
+  referrerId: string | null;
+
+  /** 注册时填写的推荐码 (即推荐人的推荐码) */
+  @Column({ name: 'used_code', type: 'varchar', length: 20, nullable: true })
+  usedCode: string | null;
+
+  /**
+   * 推荐链: [直接推荐人 userId, 推荐人的推荐人 userId, ...]
+   * PostgreSQL text[] 类型
+   */
+  @Column({ name: 'referral_chain', type: 'text', array: true, default: [] })
+  referralChain: string[];
+
+  /** 直推下级人数 */
+  @Column({ name: 'direct_referral_count', type: 'int', default: 0 })
+  directReferralCount: number;
+
+  @CreateDateColumn({ name: 'created_at' })
+  createdAt: Date;
+
+  @UpdateDateColumn({ name: 'updated_at' })
+  updatedAt: Date;
+
+  /* ── Domain Logic ── */
+
+  /**
+   * 工厂方法: 创建新推荐档案
+   */
+  static create(params: {
+    userId: string;
+    referralCode: string;
+    referrerId: string | null;
+    usedCode: string | null;
+    referralChain: string[];
+  }): ReferralProfile {
+    const profile = new ReferralProfile();
+    profile.userId = params.userId;
+    profile.referralCode = params.referralCode;
+    profile.referrerId = params.referrerId;
+    profile.usedCode = params.usedCode;
+    profile.referralChain = params.referralChain;
+    profile.directReferralCount = 0;
+    return profile;
+  }
+
+  /** 新用户加入后递增直推计数 */
+  incrementDirectReferral(): void {
+    this.directReferralCount += 1;
+  }
+
+  /** 获取推荐链值对象 */
+  getChain(): ReferralChain {
+    return ReferralChain.fromArray(this.referralChain);
+  }
+
+  /** 获取推荐码值对象 */
+  getCode(): ReferralCode {
+    return ReferralCode.create(this.referralCode);
+  }
+}
diff --git a/backend/services/referral-service/src/domain/repositories/referral-profile.repository.interface.ts b/backend/services/referral-service/src/domain/repositories/referral-profile.repository.interface.ts
new file mode 100644
index 0000000..9f8b933
--- /dev/null
+++ b/backend/services/referral-service/src/domain/repositories/referral-profile.repository.interface.ts
@@ -0,0 +1,12 @@
+import { ReferralProfile } from '../entities/referral-profile.entity';
+
+export const REFERRAL_PROFILE_REPOSITORY = 'REFERRAL_PROFILE_REPOSITORY';
+
+export interface IReferralProfileRepository {
+  findByUserId(userId: string): Promise<ReferralProfile | null>;
+  findByCode(code: string): Promise<ReferralProfile | null>;
+  existsByCode(code: string): Promise<boolean>;
+  existsByUserId(userId: string): Promise<boolean>;
+  findDirectReferrals(referrerId: string, offset: number, limit: number): Promise<[ReferralProfile[], number]>;
+  save(profile: ReferralProfile): Promise<ReferralProfile>;
+}
diff --git a/backend/services/referral-service/src/domain/value-objects/referral-chain.vo.ts b/backend/services/referral-service/src/domain/value-objects/referral-chain.vo.ts
new file mode 100644
index 0000000..1c38c31
--- /dev/null
+++ b/backend/services/referral-service/src/domain/value-objects/referral-chain.vo.ts
@@ -0,0 +1,58 @@
+/**
+ * ReferralChain Value Object
+ * 推荐链: 存储从直接推荐人到顶层的有序 userId 数组
+ * chain[0] = 直接推荐人, chain[1] = 推荐人的推荐人, ...
+ */
+export class ReferralChain {
+  private static readonly MAX_DEPTH = 50;
+
+  private constructor(private readonly _chain: string[]) {
+    if (_chain.length > ReferralChain.MAX_DEPTH) {
+      throw new Error(`推荐链深度不能超过 ${ReferralChain.MAX_DEPTH}`);
+    }
+  }
+
+  static empty(): ReferralChain {
+    return new ReferralChain([]);
+  }
+
+  static fromArray(chain: string[]): ReferralChain {
+    return new ReferralChain([...chain]);
+  }
+
+  /**
+   * 构建新用户的推荐链: 将推荐人 prepend 到其推荐链前
+   */
+  static buildFromReferrer(referrerId: string, referrerChain: string[]): ReferralChain {
+    const chain = [referrerId, ...referrerChain];
+    return new ReferralChain(chain.slice(0, ReferralChain.MAX_DEPTH));
+  }
+
+  get depth(): number {
+    return this._chain.length;
+  }
+
+  /** 直接推荐人 (chain[0]) */
+  get directReferrer(): string | null {
+    return this._chain[0] ?? null;
+  }
+
+  /** 获取第 N 级上级 (1-based, 1 = 直接推荐人) */
+  getReferrerAtLevel(level: number): string | null {
+    return this._chain[level - 1] ?? null;
+  }
+
+  /** 所有祖先 */
+  getAllAncestors(): string[] {
+    return [...this._chain];
+  }
+
+  toArray(): string[] {
+    return [...this._chain];
+  }
+
+  /** 检查 userId 是否已在链中 (防止循环推荐) */
+  contains(userId: string): boolean {
+    return this._chain.includes(userId);
+  }
+}
diff --git a/backend/services/referral-service/src/domain/value-objects/referral-code.vo.ts b/backend/services/referral-service/src/domain/value-objects/referral-code.vo.ts
new file mode 100644
index 0000000..102dc4f
--- /dev/null
+++ b/backend/services/referral-service/src/domain/value-objects/referral-code.vo.ts
@@ -0,0 +1,39 @@
+/**
+ * ReferralCode Value Object
+ * 格式: GNX + 5位大写字母数字 (共8位, 去除易混淆字符 0/O/I/1)
+ */
+export class ReferralCode {
+  private static readonly ALPHABET = 'ABCDEFGHJKLMNPQRSTUVWXYZ23456789';
+  private static readonly PATTERN = /^[A-Z0-9]{6,20}$/;
+
+  private constructor(public readonly value: string) {
+    if (!ReferralCode.PATTERN.test(value)) {
+      throw new Error(`推荐码格式无效: ${value}`);
+    }
+  }
+
+  static create(raw: string): ReferralCode {
+    return new ReferralCode(raw.toUpperCase().trim());
+  }
+
+  /**
+   * 基于 userId 生成确定性推荐码 (GNX + 5位随机字符)
+   * 调用方应检查唯一性后重试
+   */
+  static generate(): ReferralCode {
+    const prefix = 'GNX';
+    let suffix = '';
+    for (let i = 0; i < 5; i++) {
+      suffix += ReferralCode.ALPHABET[Math.floor(Math.random() * ReferralCode.ALPHABET.length)];
+    }
+    return new ReferralCode(`${prefix}${suffix}`);
+  }
+
+  equals(other: ReferralCode): boolean {
+    return this.value === other.value;
+  }
+
+  toString(): string {
+    return this.value;
+  }
+}
diff --git a/backend/services/referral-service/src/infrastructure/persistence/referral-profile.repository.ts b/backend/services/referral-service/src/infrastructure/persistence/referral-profile.repository.ts
new file mode 100644
index 0000000..30dc313
--- /dev/null
+++ b/backend/services/referral-service/src/infrastructure/persistence/referral-profile.repository.ts
@@ -0,0 +1,48 @@
+import { Injectable } from '@nestjs/common';
+import { InjectRepository } from '@nestjs/typeorm';
+import { Repository } from 'typeorm';
+import { ReferralProfile } from '../../domain/entities/referral-profile.entity';
+import { IReferralProfileRepository } from '../../domain/repositories/referral-profile.repository.interface';
+
+@Injectable()
+export class ReferralProfileRepository implements IReferralProfileRepository {
+  constructor(
+    @InjectRepository(ReferralProfile)
+    private readonly repo: Repository<ReferralProfile>,
+  ) {}
+
+  async findByUserId(userId: string): Promise<ReferralProfile | null> {
+    return this.repo.findOne({ where: { userId } });
+  }
+
+  async findByCode(code: string): Promise<ReferralProfile | null> {
+    return this.repo.findOne({ where: { referralCode: code.toUpperCase() } });
+  }
+
+  async existsByCode(code: string): Promise<boolean> {
+    const count = await this.repo.count({ where: { referralCode: code.toUpperCase() } });
+    return count > 0;
+  }
+
+  async existsByUserId(userId: string): Promise<boolean> {
+    const count = await this.repo.count({ where: { userId } });
+    return count > 0;
+  }
+
+  async findDirectReferrals(
+    referrerId: string,
+    offset: number,
+    limit: number,
+  ): Promise<[ReferralProfile[], number]> {
+    return this.repo.findAndCount({
+      where: { referrerId },
+      order: { createdAt: 'DESC' },
+      skip: offset,
+      take: limit,
+    });
+  }
+
+  async save(profile: ReferralProfile): Promise<ReferralProfile> {
+    return this.repo.save(profile);
+  }
+}
diff --git a/backend/services/referral-service/src/infrastructure/strategies/jwt.strategy.ts b/backend/services/referral-service/src/infrastructure/strategies/jwt.strategy.ts
new file mode 100644
index 0000000..08d1c50
--- /dev/null
+++ b/backend/services/referral-service/src/infrastructure/strategies/jwt.strategy.ts
@@ -0,0 +1,18 @@
+import { Injectable } from '@nestjs/common';
+import { PassportStrategy } from '@nestjs/passport';
+import { ExtractJwt, Strategy } from 'passport-jwt';
+
+@Injectable()
+export class JwtStrategy extends PassportStrategy(Strategy) {
+  constructor() {
+    super({
+      jwtFromRequest: ExtractJwt.fromAuthHeaderAsBearerToken(),
+      ignoreExpiration: false,
+      secretOrKey: process.env.JWT_ACCESS_SECRET || 'dev-access-secret',
+    });
+  }
+
+  async validate(payload: any) {
+    return { sub: payload.sub, role: payload.role, kycLevel: payload.kycLevel };
+  }
+}
diff --git a/backend/services/referral-service/src/interface/http/controllers/health.controller.ts b/backend/services/referral-service/src/interface/http/controllers/health.controller.ts
new file mode 100644
index 0000000..c119fa5
--- /dev/null
+++ b/backend/services/referral-service/src/interface/http/controllers/health.controller.ts
@@ -0,0 +1,11 @@
+import { Controller, Get } from '@nestjs/common';
+import { ApiTags } from '@nestjs/swagger';
+
+@ApiTags('Health')
+@Controller('health')
+export class HealthController {
+  @Get()
+  check() {
+    return { status: 'ok', service: 'referral-service' };
+  }
+}
diff --git a/backend/services/referral-service/src/interface/http/controllers/internal-referral.controller.ts b/backend/services/referral-service/src/interface/http/controllers/internal-referral.controller.ts
new file mode 100644
index 0000000..f3963a8
--- /dev/null
+++ b/backend/services/referral-service/src/interface/http/controllers/internal-referral.controller.ts
@@ -0,0 +1,41 @@
+import { Controller, Post, Body, Get, Param, HttpCode } from '@nestjs/common';
+import { ApiTags, ApiOperation } from '@nestjs/swagger';
+import { IsString, IsOptional } from 'class-validator';
+import { ReferralService } from '../../../application/services/referral.service';
+
+class CreateProfileDto {
+  @IsString()
+  userId: string;
+
+  @IsOptional()
+  @IsString()
+  usedCode?: string;
+}
+
+/**
+ * 内网专用接口 (不经过 Kong 对外暴露)
+ * 供 auth-service 在无 Kafka 时直接调用
+ */
+@ApiTags('Internal - Referral')
+@Controller('internal/referral')
+export class InternalReferralController {
+  constructor(private readonly referralService: ReferralService) {}
+
+  @Post('profiles')
+  @HttpCode(201)
+  @ApiOperation({ summary: '[内网] 创建推荐档案 (注册成功后调用)' })
+  async createProfile(@Body() dto: CreateProfileDto) {
+    const result = await this.referralService.createProfile({
+      userId: dto.userId,
+      usedCode: dto.usedCode ?? null,
+    });
+    return { code: 0, data: result };
+  }
+
+  @Get('profiles/:userId')
+  @ApiOperation({ summary: '[内网] 获取用户推荐档案' })
+  async getProfile(@Param('userId') userId: string) {
+    const info = await this.referralService.getMyInfo(userId);
+    return { code: 0, data: info };
+  }
+}
diff --git a/backend/services/referral-service/src/interface/http/controllers/referral.controller.ts b/backend/services/referral-service/src/interface/http/controllers/referral.controller.ts
new file mode 100644
index 0000000..8b4adba
--- /dev/null
+++ b/backend/services/referral-service/src/interface/http/controllers/referral.controller.ts
@@ -0,0 +1,55 @@
+import {
+  Controller,
+  Get,
+  Query,
+  Req,
+  UseGuards,
+  ParseIntPipe,
+  DefaultValuePipe,
+  BadRequestException,
+} from '@nestjs/common';
+import { ApiTags, ApiOperation, ApiBearerAuth, ApiQuery } from '@nestjs/swagger';
+import { AuthGuard } from '@nestjs/passport';
+import { ReferralService } from '../../../application/services/referral.service';
+
+@ApiTags('Referral')
+@Controller('referral')
+export class ReferralController {
+  constructor(private readonly referralService: ReferralService) {}
+
+  /** 获取我的推荐信息 (推荐码 + 推荐人 + 直推人数) */
+  @Get('my')
+  @UseGuards(AuthGuard('jwt'))
+  @ApiBearerAuth()
+  @ApiOperation({ summary: '获取我的推荐信息' })
+  async getMyInfo(@Req() req: any) {
+    const userId: string = req.user.sub;
+    const info = await this.referralService.getMyInfo(userId);
+    return { code: 0, data: info };
+  }
+
+  /** 验证推荐码是否有效 (公开接口，注册页面调用) */
+  @Get('validate')
+  @ApiOperation({ summary: '验证推荐码' })
+  @ApiQuery({ name: 'code', description: '推荐码', example: 'GNXAB123' })
+  async validateCode(@Query('code') code: string) {
+    if (!code) throw new BadRequestException('缺少推荐码参数');
+    const result = await this.referralService.validateCode(code);
+    return { code: 0, data: result };
+  }
+
+  /** 获取我的直推列表 */
+  @Get('direct')
+  @UseGuards(AuthGuard('jwt'))
+  @ApiBearerAuth()
+  @ApiOperation({ summary: '获取直推下级列表' })
+  async getDirectReferrals(
+    @Req() req: any,
+    @Query('offset', new DefaultValuePipe(0), ParseIntPipe) offset: number,
+    @Query('limit', new DefaultValuePipe(20), ParseIntPipe) limit: number,
+  ) {
+    const userId: string = req.user.sub;
+    const result = await this.referralService.getDirectReferrals(userId, offset, Math.min(limit, 100));
+    return { code: 0, data: result };
+  }
+}
diff --git a/backend/services/referral-service/src/main.ts b/backend/services/referral-service/src/main.ts
new file mode 100644
index 0000000..f512d15
--- /dev/null
+++ b/backend/services/referral-service/src/main.ts
@@ -0,0 +1,37 @@
+import { NestFactory } from '@nestjs/core';
+import { ValidationPipe, Logger } from '@nestjs/common';
+import { SwaggerModule, DocumentBuilder } from '@nestjs/swagger';
+import { AppModule } from './app.module';
+
+async function bootstrap() {
+  const app = await NestFactory.create(AppModule);
+  const logger = new Logger('ReferralService');
+
+  app.setGlobalPrefix('api/v1');
+  app.useGlobalPipes(
+    new ValidationPipe({ whitelist: true, forbidNonWhitelisted: true, transform: true }),
+  );
+  app.enableCors({
+    origin: process.env.CORS_ORIGINS?.split(',') || ['http://localhost:3000'],
+    credentials: true,
+  });
+
+  const swaggerConfig = new DocumentBuilder()
+    .setTitle('Genex Referral Service')
+    .setDescription('推荐码管理 — 推荐关系追踪、推荐链维护、直推统计')
+    .setVersion('1.0')
+    .addBearerAuth()
+    .addTag('Referral')
+    .build();
+  const document = SwaggerModule.createDocument(app, swaggerConfig);
+  SwaggerModule.setup('docs', app, document);
+
+  app.enableShutdownHooks();
+
+  const port = process.env.PORT || 3013;
+  await app.listen(port);
+  logger.log(`Referral Service running on port ${port}`);
+  logger.log(`Swagger docs: http://localhost:${port}/docs`);
+}
+
+bootstrap();
diff --git a/backend/services/referral-service/src/referral.module.ts b/backend/services/referral-service/src/referral.module.ts
new file mode 100644
index 0000000..40d112f
--- /dev/null
+++ b/backend/services/referral-service/src/referral.module.ts
@@ -0,0 +1,41 @@
+import { Module } from '@nestjs/common';
+import { TypeOrmModule } from '@nestjs/typeorm';
+import { PassportModule } from '@nestjs/passport';
+import { JwtModule } from '@nestjs/jwt';
+
+// Domain
+import { ReferralProfile } from './domain/entities/referral-profile.entity';
+import { REFERRAL_PROFILE_REPOSITORY } from './domain/repositories/referral-profile.repository.interface';
+
+// Infrastructure
+import { ReferralProfileRepository } from './infrastructure/persistence/referral-profile.repository';
+import { JwtStrategy } from './infrastructure/strategies/jwt.strategy';
+
+// Application
+import { ReferralService } from './application/services/referral.service';
+import { UserRegisteredHandler } from './application/event-handlers/user-registered.handler';
+
+// Interface
+import { ReferralController } from './interface/http/controllers/referral.controller';
+import { InternalReferralController } from './interface/http/controllers/internal-referral.controller';
+import { HealthController } from './interface/http/controllers/health.controller';
+
+@Module({
+  imports: [
+    TypeOrmModule.forFeature([ReferralProfile]),
+    PassportModule.register({ defaultStrategy: 'jwt' }),
+    JwtModule.register({
+      secret: process.env.JWT_ACCESS_SECRET || 'dev-access-secret',
+      signOptions: { expiresIn: '15m' },
+    }),
+  ],
+  controllers: [HealthController, ReferralController, InternalReferralController],
+  providers: [
+    { provide: REFERRAL_PROFILE_REPOSITORY, useClass: ReferralProfileRepository },
+    JwtStrategy,
+    ReferralService,
+    UserRegisteredHandler,
+  ],
+  exports: [ReferralService],
+})
+export class ReferralModule {}
diff --git a/backend/services/referral-service/tsconfig.json b/backend/services/referral-service/tsconfig.json
new file mode 100644
index 0000000..86c3af3
--- /dev/null
+++ b/backend/services/referral-service/tsconfig.json
@@ -0,0 +1,17 @@
+{
+  "compilerOptions": {
+    "module": "commonjs",
+    "target": "ES2021",
+    "lib": ["ES2021"],
+    "outDir": "./dist",
+    "rootDir": "./src",
+    "strict": false,
+    "declaration": true,
+    "esModuleInterop": true,
+    "experimentalDecorators": true,
+    "emitDecoratorMetadata": true,
+    "skipLibCheck": true,
+    "forceConsistentCasingInFileNames": true
+  },
+  "include": ["src/**/*"]
+}
diff --git a/frontend/genex-mobile/lib/app/i18n/strings/en.dart b/frontend/genex-mobile/lib/app/i18n/strings/en.dart
index 8239133..0b1f945 100644
--- a/frontend/genex-mobile/lib/app/i18n/strings/en.dart
+++ b/frontend/genex-mobile/lib/app/i18n/strings/en.dart
@@ -85,6 +85,10 @@ const Map<String, String> en = {
   'register.errorCodeInvalid': 'Please enter a 6-digit code',
   'register.errorPasswordWeak': 'Password must be 8+ characters with letters and numbers',
   'register.errorTermsRequired': 'Please agree to the Terms of Service',
+  'register.referralCode': 'Referral Code (optional)',
+  'register.referralCodeHint': 'Enter inviter\'s referral code',
+  'register.referralCodeValid': 'Referral code is valid',
+  'register.referralCodeInvalid': 'Invalid referral code',
 
   'forgot.title': 'Reset Password',
   'forgot.inputAccount': 'Enter phone or email',
diff --git a/frontend/genex-mobile/lib/app/i18n/strings/ja.dart b/frontend/genex-mobile/lib/app/i18n/strings/ja.dart
index 4ef42e2..755cd2d 100644
--- a/frontend/genex-mobile/lib/app/i18n/strings/ja.dart
+++ b/frontend/genex-mobile/lib/app/i18n/strings/ja.dart
@@ -85,6 +85,10 @@ const Map<String, String> ja = {
   'register.errorCodeInvalid': '6桁の認証コードを入力してください',
   'register.errorPasswordWeak': 'パスワードは8文字以上で英字と数字を含む必要があります',
   'register.errorTermsRequired': '利用規約に同意してください',
+  'register.referralCode': '紹介コード（任意）',
+  'register.referralCodeHint': '招待者の紹介コードを入力',
+  'register.referralCodeValid': '紹介コードは有効です',
+  'register.referralCodeInvalid': '紹介コードが無効です',
 
   'forgot.title': 'パスワード再設定',
   'forgot.inputAccount': '電話番号またはメールを入力',
diff --git a/frontend/genex-mobile/lib/app/i18n/strings/zh_cn.dart b/frontend/genex-mobile/lib/app/i18n/strings/zh_cn.dart
index 7648528..a5c146f 100644
--- a/frontend/genex-mobile/lib/app/i18n/strings/zh_cn.dart
+++ b/frontend/genex-mobile/lib/app/i18n/strings/zh_cn.dart
@@ -85,6 +85,10 @@ const Map<String, String> zhCN = {
   'register.errorCodeInvalid': '请输入6位验证码',
   'register.errorPasswordWeak': '密码需要8位以上且包含字母和数字',
   'register.errorTermsRequired': '请先阅读并同意用户协议',
+  'register.referralCode': '推荐码（选填）',
+  'register.referralCodeHint': '输入邀请人的推荐码',
+  'register.referralCodeValid': '推荐码有效',
+  'register.referralCodeInvalid': '推荐码无效',
 
   'forgot.title': '找回密码',
   'forgot.inputAccount': '输入手机号或邮箱',
diff --git a/frontend/genex-mobile/lib/app/i18n/strings/zh_tw.dart b/frontend/genex-mobile/lib/app/i18n/strings/zh_tw.dart
index 9f1cf95..7696cdb 100644
--- a/frontend/genex-mobile/lib/app/i18n/strings/zh_tw.dart
+++ b/frontend/genex-mobile/lib/app/i18n/strings/zh_tw.dart
@@ -85,6 +85,10 @@ const Map<String, String> zhTW = {
   'register.errorCodeInvalid': '請輸入6位驗證碼',
   'register.errorPasswordWeak': '密碼需要8位以上且包含字母和數字',
   'register.errorTermsRequired': '請先閱讀並同意使用者協議',
+  'register.referralCode': '推薦碼（選填）',
+  'register.referralCodeHint': '輸入邀請人的推薦碼',
+  'register.referralCodeValid': '推薦碼有效',
+  'register.referralCodeInvalid': '推薦碼無效',
 
   'forgot.title': '找回密碼',
   'forgot.inputAccount': '輸入手機號或信箱',
diff --git a/frontend/genex-mobile/lib/core/services/auth_service.dart b/frontend/genex-mobile/lib/core/services/auth_service.dart
index b09de09..8ce926e 100644
--- a/frontend/genex-mobile/lib/core/services/auth_service.dart
+++ b/frontend/genex-mobile/lib/core/services/auth_service.dart
@@ -62,6 +62,19 @@ class AuthService {
     return data['expiresIn'] as int;
   }
 
+  /* ── 推荐码 ── */
+
+  /// 验证推荐码是否有效 (调用 referral-service)
+  Future<bool> validateReferralCode(String code) async {
+    try {
+      final resp = await _api.get('/api/v1/referral/validate', queryParameters: {'code': code});
+      final data = resp.data['data'] as Map<String, dynamic>;
+      return data['valid'] == true;
+    } catch (_) {
+      return false;
+    }
+  }
+
   /* ── 注册 ── */
 
   /// 手机号注册 (需先获取 REGISTER 类型验证码)
@@ -70,12 +83,15 @@ class AuthService {
     required String smsCode,
     required String password,
     String? nickname,
+    String? referralCode,
   }) async {
     final resp = await _api.post('/api/v1/auth/register', data: {
       'phone': phone,
       'smsCode': smsCode,
       'password': password,
       if (nickname != null) 'nickname': nickname,
+      if (referralCode != null && referralCode.isNotEmpty)
+        'referralCode': referralCode.toUpperCase(),
     });
     final result = AuthResult.fromJson(resp.data['data']);
     _setAuth(result);
diff --git a/frontend/genex-mobile/lib/features/auth/presentation/pages/register_page.dart b/frontend/genex-mobile/lib/features/auth/presentation/pages/register_page.dart
index 0570f64..fffc421 100644
--- a/frontend/genex-mobile/lib/features/auth/presentation/pages/register_page.dart
+++ b/frontend/genex-mobile/lib/features/auth/presentation/pages/register_page.dart
@@ -24,10 +24,13 @@ class _RegisterPageState extends State<RegisterPage> {
   final _accountController = TextEditingController();
   final _codeController = TextEditingController();
   final _passwordController = TextEditingController();
+  final _referralCodeController = TextEditingController();
   bool _obscurePassword = true;
   bool _agreeTerms = false;
   bool _loading = false;
   String? _errorMessage;
+  // null=未验证, true=有效, false=无效
+  bool? _referralCodeValid;
 
   final _authService = AuthService.instance;
 
@@ -42,9 +45,23 @@ class _RegisterPageState extends State<RegisterPage> {
     _accountController.dispose();
     _codeController.dispose();
     _passwordController.dispose();
+    _referralCodeController.dispose();
     super.dispose();
   }
 
+  Future<void> _validateReferralCode(String code) async {
+    if (code.isEmpty) {
+      setState(() => _referralCodeValid = null);
+      return;
+    }
+    try {
+      final resp = await _authService.validateReferralCode(code);
+      setState(() => _referralCodeValid = resp);
+    } catch (_) {
+      setState(() => _referralCodeValid = false);
+    }
+  }
+
   String _extractError(DioException e) {
     final data = e.response?.data;
     if (data is Map && data['message'] != null) {
@@ -96,10 +113,12 @@ class _RegisterPageState extends State<RegisterPage> {
 
     setState(() { _loading = true; _errorMessage = null; });
     try {
+      final referralCode = _referralCodeController.text.trim();
       await _authService.register(
         phone: phone,
         smsCode: code,
         password: password,
+        referralCode: referralCode.isNotEmpty ? referralCode : null,
       );
       if (mounted) Navigator.pushReplacementNamed(context, '/main');
     } on DioException catch (e) {
@@ -238,7 +257,40 @@ class _RegisterPageState extends State<RegisterPage> {
               ),
               const SizedBox(height: 8),
               _buildPasswordStrength(),
-              const SizedBox(height: 32),
+              const SizedBox(height: 20),
+
+              // Referral code (optional)
+              Text(context.t('register.referralCode'), style: AppTypography.labelMedium),
+              const SizedBox(height: 8),
+              TextField(
+                controller: _referralCodeController,
+                textCapitalization: TextCapitalization.characters,
+                onChanged: (v) {
+                  setState(() => _referralCodeValid = null);
+                  if (v.length >= 6) _validateReferralCode(v.trim());
+                },
+                decoration: InputDecoration(
+                  hintText: context.t('register.referralCodeHint'),
+                  prefixIcon: const Icon(Icons.card_giftcard_rounded, color: AppColors.textTertiary),
+                  suffixIcon: _referralCodeValid == null
+                      ? null
+                      : Icon(
+                          _referralCodeValid! ? Icons.check_circle_rounded : Icons.cancel_rounded,
+                          color: _referralCodeValid! ? AppColors.success : AppColors.error,
+                          size: 20,
+                        ),
+                  helperText: _referralCodeValid == null
+                      ? null
+                      : _referralCodeValid!
+                          ? context.t('register.referralCodeValid')
+                          : context.t('register.referralCodeInvalid'),
+                  helperStyle: TextStyle(
+                    color: _referralCodeValid == true ? AppColors.success : AppColors.error,
+                    fontSize: 12,
+                  ),
+                ),
+              ),
+              const SizedBox(height: 24),
 
               // Step 3: Terms + Submit
               Row(