# NestJS v12.0.0

- Product: NestJS (https://whatsnew.fyi/product/nestjs)
- Vendor: NestJS
- Date: 2026-08-27
- Version: v12.0.0
- Original notes: https://github.com/nestjs/nest/releases/tag/v12.0.0
- Permalink: https://whatsnew.fyi/product/nestjs/releases/v12.0.0

What's New is an index, not a publisher: every entry below links to the vendor's own release notes, which are the authoritative source. Entries are labelled where they are hand-curated sample data, pre-releases, or drawn from a secondary source such as a developer blog.

Reuse: the summaries, labels and curation here are © What's New. Quote freely with attribution and a link back; wholesale republication of the corpus is not permitted — terms: https://whatsnew.fyi/terms. The vendors' own release notes remain their publishers'.

---

- **added** — ESM packages for all core Nest packages with CommonJS compatibility through require(esm) in Node.js v20.19+ or v22.12+
- **added** — Standard Schema validation support via schema option in @Body(), @Query(), @Param(), and @RawBody() decorators
- **added** — StandardSchemaValidationPipe for validating requests against Standard Schema compatible libraries
- **added** — StandardSchemaSerializerInterceptor for validating and transforming outgoing responses with Standard Schema
- **added** — @nestjs/observe SDK for native observability with automatic instrumentation of HTTP, GraphQL, gRPC, microservice transports, queue consumers, and cron runs
- **added** — Route conflict diagnostics with routeConflictPolicy and routeResolutionStrategy options to detect duplicate and shadow routes
- **added** — Machine-readable error codes via errorCode option in HttpExceptionOptions
- **added** — Structured logging params in ConsoleLogger treating plain objects after messages as structured fields
- **changed** — @nestjs/config validation now accepts Standard Schema compatible schemas via validationSchema option
- **changed** — nest new command now offers choice to scaffold CommonJS or ESM projects
- **changed** — nest upgrade command applies mechanical migrations including webpack options, GraphQL playground to graphiql rename, NATS package replacement, and Jest and Joi bumps
- **changed** — Node.js minimum requirement is v20.19+ or v22.12+
- **removed** — Implicit CommonJS-only packages support removed in favor of ESM-ready packages

#### NestJS v12.0.0

NestJS 12 is centered around **ESM-ready packages**, **first-class [Standard Schema](https://standardschema.dev/) support** for validation and serialization, a **rebuilt CLI**, and **native observability** through the new `@nestjs/observe` SDK.

Existing CommonJS applications keep working — migrating your own code to ESM is entirely optional.

📖 Full [migration guide](https://docs.nestjs.com/migration-guide) 

---

##### Upgrading

Upgrade the CLI first, since the upgrade command ships with it:

```bash
npm i -g @nestjs/cli@latest
```

Then, from the root of your project:

```bash
nest upgrade
```

`nest upgrade` moves every `@nestjs/*` package to its v12-compatible major at once and applies the mechanical parts of the migration for you — `nest-cli.json` webpack options, the GraphQL `playground` → `graphiql` rename and subscriptions transport swap, the NATS package replacement, `@nestjs/config` validation options, Jest and Joi bumps — then prints a report of everything it changed and everything you still need to review by hand. Run it with `--dry-run` first to see that report without touching your files.

It deliberately does **not** migrate your project to ESM, Vitest, or oxlint. Those are the defaults for newly generated projects; existing projects adopt them on their own schedule.

**Node.js:** v12 requires **Node.js v20.19+ or v22.12+**. Both `require(esm)` and the ESM packages depend on it; the upgrade command refuses to run on older releases (including the 21.x line). The latest active LTS is recommended.

---

##### Highlights

###### ESM packages

All core Nest packages now ship as ESM. Thanks to `require(esm)` in modern Node.js, most existing CommonJS applications continue to work without a rewrite. Review custom bootstrapping scripts, build tooling, and test runners if they assume CommonJS-only packages.

`nest new` now asks whether to scaffold a **CommonJS** or an **ESM** project.

###### Standard Schema validation

Route parameter decorators — `@Body()`, `@Query()`, `@Param()`, `@RawBody()` — accept a new `schema` option, designed for Standard Schema compatible libraries such as Zod, Valibot, and ArkType:

```ts
@Post()
create(@Body({ schema: createUserSchema }) body: CreateUserDto) {
  return this.usersService.create(body);
}

@Get(':id')
findOne(@Param('id', { schema: z.coerce.number().int().positive() }) id: number) {
  return this.usersService.findOne(id);
}
```

The decorator only attaches metadata; register the new `StandardSchemaValidationPipe` to validate against it:

```ts
app.useGlobalPipes(new StandardSchemaValidationPipe());
```

The same schemas feed OpenAPI generation. The decorator-based `class-validator` workflow remains fully supported, with no plan to remove it.

###### Standard Schema serialization

`StandardSchemaSerializerInterceptor` validates and transforms outgoing responses with the same ecosystem:

```ts
@UseInterceptors(StandardSchemaSerializerInterceptor)
@SerializeOptions({ schema: userResponseSchema })
@Get(':id')
findOne(@Param('id') id: string) {
  return this.usersService.findOne(id);
}
```

Pick per use case: `ValidationPipe` / `ClassSerializerInterceptor` for class-based DTOs, the Standard Schema variants when your schemas already exist.

###### Native observability — `@nestjs/observe`

The official [NestJS Observe](https://observe.nestjs.com) SDK plugs into Nest's own request lifecycle through the `instrument` application option, rather than patching the HTTP server like a generic APM agent. Requests, jobs, errors, and traces are reported in terms of your controllers, providers, resolvers, and queue consumers:

```ts
export const { ObserveModule, ObserveInstrument } = createObserveModule();

const app = await NestFactory.create(AppModule, {
  instrument: ObserveInstrument,
});
```

Auto-instrumentation covers HTTP, GraphQL, gRPC, and microservice transports, plus queue

_[Truncated at 4000 characters — full notes: https://github.com/nestjs/nest/releases/tag/v12.0.0]_