Health Endpoint Configuration and Shutdown

FULL_STACK_DEVELOPER_2026_COMPLETE - Phase 04 Health Endpoint, Configuration and Shutdown

VOLUME 02 - FRONTEND + BACKEND FOUNDATIONS

Health Endpoint, Configuration and Shutdown Create the first durable TaskFlow backend checkpoint

Next.js NestJS + Fastify separate applications apps/web - already built apps/api - this phase

Browser

renders TaskFlow UI

Figure - Phase 04 keeps frontend and backend independent. They will communicate later in Phase 06.

Book 6 of Phase 04

FULL_STACK_DEVELOPER_2026_COMPLETE - Phase 04 Health Endpoint, Configuration and Shutdown

Build a health endpoint as the backend proof point

GET /health HealthController HealthService 200 JSON

HTTP request route boundary returns status observable result

A health endpoint proves the API process is alive before database or authentication complexity is added.

Figure - Health endpoint as a minimal, verifiable backend checkpoint.

apps/api/src/health/health.service.ts
import { Injectable } from '@nestjs/common';

@Injectable()
export class HealthService {
getStatus() {
return {
status: 'ok',
service: 'taskflow-api',
};
}
}

apps/api/src/health/health.controller.ts
import { Controller, Get } from '@nestjs/common';
import { HealthService } from './health.service.js';

@Controller('health')
export class HealthController {
constructor(private readonly healthService: HealthService) {}

@Get()
getHealth() {
return this.healthService.getStatus();
}
}

apps/api/src/health/health.module.ts
import { Module } from '@nestjs/common';
import { HealthController } from './health.controller.js';
import { HealthService } from './health.service.js';

@Module({
controllers: [HealthController],
providers: [HealthService],
})
export class HealthModule {}

Compose the feature into AppModule
apps/api/src/app.module.ts
import { Module } from '@nestjs/common';
import { HealthModule } from './health/health.module.js';

@Module({
imports: [HealthModule],
})
export class AppModule {}

FULL_STACK_DEVELOPER_2026_COMPLETE - Phase 04 Health Endpoint, Configuration and Shutdown

Once HealthModule owns the working endpoint, the generated AppController and AppService no longer have a responsibility and can be removed. This is cleanup based on responsibility, not cleanup for aesthetics.

Add a minimal startup configuration main.ts - relevant section async function bootstrap() { const app = await NestFactory.create<NestFastifyApplication>( AppModule, new FastifyAdapter(), );

app.enableShutdownHooks();

const port = Number(process.env.PORT ?? 4000);
await app.listen(port, '127.0.0.1');
}

At this phase, PORT is the only environment-aware value we need. We do not introduce @nestjs/config or a large configuration system until configuration complexity exists.

Shutdown hooks

enableShutdownHooks() lets Nest participate in process shutdown signals. Later, database connections and background workers will have meaningful cleanup work. Introducing the hook now establishes the lifecycle without creating those dependencies early.

Verify without the frontend Second PowerShell window Invoke-RestMethod -Uri 'http://127.0.0.1:4000/health' -Method Get

Expected PowerShell object view status service ------ ------- ok taskflow-api

Checkpoint D

GET /health succeeds independently. The backend is now a verifiable application even though TaskFlow web has not called it yet.

Official source notes This phase is written against NestJS 12.0.3 and the Nest CLI 12.0.3 release line. Fastify remains on the stable v5 line; the September 17, 2026 stable patch reference is 5.12.5. The course does not adopt Fastify 6 alpha builds.

Primary references: docs.nestjs.com/modules, docs.nestjs.com/providers, docs.nestjs.com/techniques/performance, github.com/nestjs/nest/releases, github.com/nestjs/nest-cli/releases, github.com/fastify/fastify/releases.