feat: add api liveness and readiness checks

backend/apps/api/src/api.module.ts

@@ -2,9 +2,10 @@ import { Module } from '@nestjs/common';
 import { ConfigurationModule } from '../../../libs/configuration/src';
 import { AppController } from './app.controller';
 import { AppService } from './app.service';
+import { HealthModule } from './health/health.module';
 
 @Module({
-  imports: [ConfigurationModule],
+  imports: [ConfigurationModule, HealthModule],
   controllers: [AppController],
   providers: [AppService],
 })

backend/apps/api/src/health/health.controller.spec.ts

@@ -0,0 +1,29 @@
+import { Test } from '@nestjs/testing';
+import { HealthController } from './health.controller';
+import { ReadinessService } from './readiness.service';
+
+describe('HealthController', () => {
+  it('returns liveness without dependency checks', async () => {
+    const readiness = { check: jest.fn() };
+    const moduleRef = await Test.createTestingModule({
+      controllers: [HealthController],
+      providers: [{ provide: ReadinessService, useValue: readiness }],
+    }).compile();
+
+    expect(moduleRef.get(HealthController).live()).toEqual({ status: 'ok' });
+    expect(readiness.check).not.toHaveBeenCalled();
+  });
+
+  it('delegates readiness to dependency checks', async () => {
+    const readiness = { check: jest.fn().mockResolvedValue({ status: 'ok' }) };
+    const moduleRef = await Test.createTestingModule({
+      controllers: [HealthController],
+      providers: [{ provide: ReadinessService, useValue: readiness }],
+    }).compile();
+
+    await expect(moduleRef.get(HealthController).ready()).resolves.toEqual({
+      status: 'ok',
+    });
+    expect(readiness.check).toHaveBeenCalledTimes(1);
+  });
+});

backend/apps/api/src/health/health.controller.ts

@@ -0,0 +1,17 @@
+import { Controller, Get } from '@nestjs/common';
+import { ReadinessService } from './readiness.service';
+
+@Controller()
+export class HealthController {
+  constructor(private readonly readiness: ReadinessService) {}
+
+  @Get('health/live')
+  live(): { status: 'ok' } {
+    return { status: 'ok' };
+  }
+
+  @Get('health/ready')
+  ready(): Promise<{ status: 'ok' }> {
+    return this.readiness.check();
+  }
+}

backend/apps/api/src/health/health.module.ts

@@ -0,0 +1,14 @@
+import { Module } from '@nestjs/common';
+import {
+  PostgresModule,
+  RedisModule,
+} from '../../../../libs/infrastructure/src';
+import { HealthController } from './health.controller';
+import { ReadinessService } from './readiness.service';
+
+@Module({
+  imports: [PostgresModule, RedisModule],
+  controllers: [HealthController],
+  providers: [ReadinessService],
+})
+export class HealthModule {}

backend/apps/api/src/health/readiness.service.ts

@@ -0,0 +1,22 @@
+import { Inject, Injectable } from '@nestjs/common';
+import type { Pool } from 'pg';
+import type Redis from 'ioredis';
+import {
+  POSTGRES_POOL,
+  REDIS_CLIENT,
+} from '../../../../libs/infrastructure/src';
+
+@Injectable()
+export class ReadinessService {
+  constructor(
+    @Inject(POSTGRES_POOL) private readonly postgresPool: Pool,
+    @Inject(REDIS_CLIENT) private readonly redis: Redis,
+  ) {}
+
+  async check(): Promise<{ status: 'ok' }> {
+    await this.postgresPool.query('SELECT 1');
+    const pong = await this.redis.ping();
+    if (pong !== 'PONG') throw new Error('Redis ping failed');
+    return { status: 'ok' as const };
+  }
+}

backend/apps/api/src/main.ts

@@ -1,10 +1,16 @@
+import { RequestMethod } from '@nestjs/common';
 import { NestFactory } from '@nestjs/core';
 import { ApiModule } from './api.module';
 
 export async function bootstrapApi(): Promise<void> {
   const app = await NestFactory.create(ApiModule);
   app.enableShutdownHooks();
-  app.setGlobalPrefix('api/v1');
+  app.setGlobalPrefix('api/v1', {
+    exclude: [
+      { path: 'health/live', method: RequestMethod.GET },
+      { path: 'health/ready', method: RequestMethod.GET },
+    ],
+  });
   await app.listen(3000, '0.0.0.0');
 }
 

backend/apps/worker/src/worker.module.ts

@@ -1,7 +1,8 @@
 import { Module } from '@nestjs/common';
 import { ConfigurationModule } from '../../../libs/configuration/src';
+import { PostgresModule, RedisModule } from '../../../libs/infrastructure/src';
 
 @Module({
-  imports: [ConfigurationModule],
+  imports: [ConfigurationModule, PostgresModule, RedisModule],
 })
 export class WorkerModule {}