Deployment

A Nest application is an ordinary Node.js server: you compile TypeScript to JavaScript and run dist/main.js with Node. This chapter covers production builds, environment configuration, and deploying with a process manager or containers. Express apps deploy the same way.

Production build

npm run build runs nest build, compiling src into dist. The output runs on plain Node.js without the Nest CLI.

npm ci
npm run build
NODE_ENV=production node dist/main
# or the generated script
npm run start:prod

Production servers do not need dev dependencies: remove them after building with npm prune --omit=dev, or install with npm ci --omit=dev. Avoid running production with ts-node or nest start. An Express app without a compile step simply runs as node src/server.js.

Production configuration

Keep configuration out of code and pass it as environment variables: the port via PORT, database URLs and secrets via your platform's secret store or environment settings. Never bake a .env file into an image or repository. A production main.ts typically adds the following.

// src/main.ts
import { ValidationPipe } from "@nestjs/common";
import { NestFactory } from "@nestjs/core";
import helmet from "helmet";
import { AppModule } from "./app.module";

async function bootstrap() {
  const app = await NestFactory.create(AppModule);
  app.use(helmet()); // security-related HTTP headers
  app.enableCors({ origin: process.env.CORS_ORIGIN });
  app.useGlobalPipes(new ValidationPipe({ whitelist: true }));
  app.enableShutdownHooks(); // clean up on SIGTERM
  await app.listen(process.env.PORT ?? 3000, "0.0.0.0");
}
bootstrap();

helmet (installed with npm i helmet) is Express middleware, and Nest uses it as is through app.use(). With enableShutdownHooks(), lifecycle hooks such as onModuleDestroy run when the container sends a termination signal, so database connections close cleanly. Behind a reverse proxy, enable Express's trust proxy setting to read the real client IP and protocol; in Nest, create the app with NestFactory.create<NestExpressApplication>() and call app.set("trust proxy", 1).

Running under a process manager

On a VM or bare server, you need something that restarts the process if it dies. PM2 is a popular Node.js process manager and can run one process per CPU core in cluster mode.

npm i -g pm2
pm2 start dist/main.js --name api -i max
pm2 logs api
pm2 save      # remember the current process list
pm2 startup   # start automatically after a reboot